WO2001001876A1 - Monopole tip for ablation catheter and methods for using same - Google Patents
Monopole tip for ablation catheter and methods for using same Download PDFInfo
- Publication number
- WO2001001876A1 WO2001001876A1 PCT/US2000/014953 US0014953W WO0101876A1 WO 2001001876 A1 WO2001001876 A1 WO 2001001876A1 US 0014953 W US0014953 W US 0014953W WO 0101876 A1 WO0101876 A1 WO 0101876A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- monopole antenna
- section
- antenna
- catheter
- transmission line
- Prior art date
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
- A61B18/04—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
- A61B18/12—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current
- A61B18/14—Probes or electrodes therefor
- A61B18/1492—Probes or electrodes therefor having a flexible, catheter-like structure, e.g. for heart ablation
Definitions
- the present invention relates generally to ablation catheter systems that use electromagnetic energy in the microwave frequency range to ablate internal bodily tissues. More particularly, the present invention relates to a monopole tip for a catheter that enables distal fire capabilities while enabling a relatively even electromagnetic field to be created at the sides of the monopole tip to facilitate the ablation of cardiac tissue.
- RF energy radio frequency
- Cardiac arrhythmias which may be treated using catheter ablation, are generally circuits, known as "arrhythmia circuits," which form within the chambers of the heart.
- arrhythmia circuits are abnormal electrical connections that may form in various areas of the heart. For example, arrhythmia circuits may form around veins and/or arteries which lead away from and to the heart. Cardiac arrhythmias may occur in any area of the heart where arrhythmia circuits are formed.
- the catheters used for treatment of cardiac arrythmias, disrhythmias, and tachycardia may have a variety of different antenna configurations to create electromagnetic fields used in ablation. Some catheters have antennas that essentially protrude from the distal ends of the catheters. In other words, some catheters have antennas which form the distal tips of the catheters. A monopole antenna is typically configured to form the distal tip of a catheter.
- Figure la is a diagrammatic representation of a distal end of a catheter with a monopole antenna at its tip.
- a distal end 102 of a catheter has a monopole antenna 108 at its tip.
- monopole antenna 108 has a rounded shape, and is coupled to a center conductor 112 of a co-axial transmission line 116.
- monopole antenna 108 is formed from a metallic material.
- Distal end 102 of the catheter may also include electrodes 120, which may be used for mapping processes, that may be coupled to processing equipment (not shown) using ECG wires 122.
- Monopole antenna 108 is often arranged to be used in ablating tissue.
- Center conductor 112 transmits energy, e.g., electromagnetic energy, to monopole antenna 108 to allow an electromagnetic field to be formed with respect to monopole antenna.
- Figure lb is a diagrammatic representation of a monopole antenna, i.e., monopole antenna 108 of Figure la, shown with electromagnetic field lines.
- Electromagnetic field lines 130 generally radiate from monopole antenna 108 in a substantially ellipsoidal pattern.
- hot spots 138 of electromagnetic energy are typically formed. Hot spots 138 are generally associated with the highest amounts of electromagnetic energy radiated by monopole antenna 108.
- the existence of hot spots 138 causes certain portions of a myocardium of heart, for example, such as those that are substantially contacted by a hot spot to be ablated more than other portions.
- the depth of cuts formed may not be uniform, since electromagnetic field lines 130 are not uniform. That is, the shape, or profile, of electromagnetic field lines 130 are such that when ablation is performed, the depth associated with the ablation may not be even.
- the lack of even depth in an ablation procedure may cause the ablation, e.g., an ablation in the myocardium of a heart, to be unsuccessful, as all of the cardiac tissue may not be effectively ablated. Hence, the ablation procedure may have to be repeated, which is both time-consuming and inefficient.
- a monopole antenna structure for use with an ablation catheter that efficiently allows tissue to be ablated. More specifically, what is desired is a monopole antenna structure that is capable of producing a relatively uniform field, e.g., electromagnetic field, a deep lesion, and a microwave power deposition at the tip of a catheter, i.e., a tip-firing catheter.
- a relatively uniform field e.g., electromagnetic field, a deep lesion, and a microwave power deposition at the tip of a catheter, i.e., a tip-firing catheter.
- an ablation catheter with a monopole antenna that is arranged to provide an electric field that is able to produce a deep lesion, e.g., in the myocardium or a heart, and has a tip-firing capability.
- an ablation catheter includes an elongated flexible tubular member that is adapted to be inserted into the body of a patient, and a transmission line that is disposed within the tubular member.
- the transmission line has a distal end and a proximal end which is arranged to be connected to an electromagnetic energy source.
- the catheter also includes a monopole antenna with tip section and a body section that includes a distal end and a proximal end.
- the tip section and the body section are arranged to produce a relatively uniform electric field around the monopole antenna which is sufficiently strong to cause deep tissue ablation.
- the proximal end of the body section of the monopole antenna is arranged to be electrically coupled to the transmission line.
- the transmission line is a coaxial cable, which has a center conductor and an outer conductor.
- the proximal end of the monopole antenna is arranged to be electrically coupled to the center conductor.
- the body section of the monopole antenna is tapered such that the diameter at the proximal end of the body section of the monopole antenna is smaller than the diameter at the distal end of the body section of the monopole antenna.
- an antenna structure arranged to be used in an ablation catheter has a longitudinal axis, and includes a body section with a first end and a second end, a tip section, and a transition section.
- the body section is sized such that the axial cross-sectional area about the longitudinal axis of the second end is smaller than the axial cross-sectional area about the longitudinal axis of the first end.
- the second end is arranged to be electrically coupled to a transmission line, and the body section is shaped to allow a relatively uniform electric field to be formed with respect to the antenna structure.
- the tip section has a proximal portion that has an axial cross-sectional area about the longitudinal axis which is greater than or approximately equal to the axial cross- sectional area of the first end, and the transition section is disposed between the proximal portion and the first end.
- a microwave ablation catheter in one embodiment, includes an elongated flexible tubular member, which has a distal portion, a proximal portion, and a longitudinal catheter axis, and is adapted to be inserted into a vessel in the body of a patient.
- the microwave ablation catheter also includes a transmission line with a proximal end and a distal end.
- the transmission line is disposed within the tubular member, and the proximal end of the transmission line is suitable for connection to an electromagnetic energy source.
- a monopole antenna which is part of the microwave ablation catheter is coupled to the transmission line for generating an electric field sufficiently strong to cause tissue ablation, and includes a frusto-conically shaped emitting surface with an axis that is substantially parallel to the longitudinal catheter axis.
- the monopole antenna further includes a rounded distal emitter surface.
- the antenna may also include a trough region between the frusto- conically shaped emitting surface and the distal emitter surface, as well as an encapsulating material that encapsulates the trough and frusto-conically shaped emitting surface such that the trough forms an anchor for the encapsulating material.
- Figure la is a diagrammatic representation of a distal end of a catheter with a monopole tip.
- Figure lb is a diagrammatic representation of a monopole antenna, i.e., monopole antenna 108 of Figure la, shown with electromagnetic field lines.
- Figure 2a is a diagrammatic representation of an ablation catheter in accordance with an embodiment of the present invention.
- Figure 2b is a perspective representation of a monopole antenna with a tapered configuration, i.e., monopole antenna 202 of Figure 2a, in accordance with an embodiment of the present invention.
- Figure 3a is a diagrammatic side view representation of a monopole antenna, shown with a contour plot of the magnitude of electric field lines, in accordance with an embodiment of the present invention.
- Figure 3b is a diagrammatic side view representation of a monopole antenna, i.e., monopole antenna 302 of Figure 3a, shown with relative specific absorption rates, in accordance with an embodiment of the present invention.
- Figure 4 is a diagrammatic cross-sectional representation of a distal end of a catheter which includes a monopole antenna in accordance with an embodiment of the present invention.
- An ablation catheter that has a monopole antenna which is shaped to enable a substantially uniform field, e.g., electromagnetic or electric field, to be formed around the monopole antenna allows the depth of an ablation of tissue to occur substantially uniformly
- a monopole antenna allows the catheter to have forward firing, or tip-firing, capabilities. That is, the distal tip of the monopole antenna may also be used to ablate tissue.
- an overall ablation process may be more efficiently performed, as it may be unnecessary to repeatedly ablate the same area of tissue to obtain an even depth of ablation.
- an overall ablation process is more efficient, in that the time spent performing ablation may be reduced.
- a monopole antenna which includes a tip section and a tapered body section enables hot spots in the electromagnetic field formed around the body section to be substantially eliminated.
- Figure 2a is a diagrammatic representation of an ablation catheter with a monopole antenna, which includes a tip section and a tapered body section, in accordance with an embodiment of the present invention.
- An ablation catheter 180 which is suitable for use as a microwave ablation catheter, is generally arranged to be introduced into the body of a patient through a blood vessel, e.g., the femoral vein.
- Catheter 180 may be considered to be an overall elongated, flexible, tube. It should be appreciated that for ease of illustration, catheter 180 has not been drawn to scale.
- catheter 180 is arranged to be used within the body of a patient, materials used to form catheter 180 are typically biocompatible materials. Suitable biocompatible materials used to form catheter 180 include, but are not limited to medical grade polyolefins, fluoropolymers, polyurethane, polyethylene, or polyvinylidene fluoride. In one embodiment, a PEBAX resin, which is available commercially from Elf Atochem of Germany, may be used in the formation of catheter 180.
- Catheter 180 includes a monopole antenna 202 from which an electric field may be emitted to cause ablation. As shown, monopole antenna 202 is located at the distal end of catheter 180. Monopole antenna 202, which may be machined from a material such as stainless steel using a mill or a lathe, will be discussed below with reference to Figure 2b. Typically, once catheter 180 is introduced into the body of a patient, catheter 180 is manipulated through a blood vessel and into the heart such that monopole antenna 202 may be positioned within a cardiac chamber in which an ablation procedure is to be performed. Catheter 180 also includes electrodes 204 which are positioned on catheter 180 such that they are located proximally with respect to monopole antenna 202.
- Electrodes 204 are generally arranged to detect electro-physiological signals from cardiac tissue. Hence, electrodes 204, which are generally electrode bands, may be used to map the relevant region of the heart, i.e., the portion of the heart with which an ablation procedure is associated, prior to or after an ablation procedure. Electrodes 204 may also be used to aid in positioning catheter 180 during an ablation procedure. In general, although electrodes 204 may be formed from any suitable material which has biocompatible characteristics, electrodes 204 are typically formed from materials which include, but are not limited to, stainless steel and iridium platinum.
- a handle 205 is often located near a proximal end of catheter 180, although it should be appreciated that handle 205 is not necessarily included as a part of catheter 180.
- Handle 205 is arranged to enable a user, i.e., an individual who is performing an ablation procedure on a patient, to grip and to manipulate catheter 180.
- a connector 206 is located on catheter 180 such that connector 206 is proximal to handle 205.
- Connector 206 is arranged to couple a transmission line (not shown), which is located within catheter 180, to a power supply, or similar device, that is designed to generate controlled electromagnetic energy.
- monopole antenna 202 is arranged to provide an electric field, e.g., an electromagnetic field, to allow tissue to be ablated.
- monopole antenna 202 is shaped such that the electric field which is generated is effectively confined to the monopole region associated with monopole antenna 202.
- Figure 2b is a perspective representation of monopole antenna 202 of Figure 2a.
- Monopole antenna 202 includes a body section 208, an intermediate section 210, and a tip section 214.
- body section 208 has a tapered shape, e.g., body section 208 is shaped substantially as a conical structure with no single apex point. That is, body section 208, which includes an emitting surface, may have a frusto-conical shape.
- a proximal end 218 of body section 208 generally has the smallest axial cross-sectional area, about a longitudinal axis of monopole antenna 202, associated with body section 208.
- the diameter of proximal end 218, about the longitudinal axis of monopole antenna 202 is typically smaller than any other diameter, along the same axis, that is associated with body section 208.
- Intermediate section 210 effectively separates body section 208 from tip section 214.
- One purpose of intermediate, or "trough,” section 210 is to allow a material which is used to encase body section 208 to be anchored with respect to monopole antenna 202.
- intermediate section 210 is shaped such that a material which effectively encapsulates body section 208 and, further, at least part of intermediate section 210, is generally prevented from "peeling away” from intermediate section 210 and body section 208.
- the encapsulating material serves as a plug that holds monopole antenna 202 against a catheter, e.g. , catheter 180 of Figure 2a.
- any suitable material may be used to form a plug that essentially encases body section 208.
- intermediate section 210 has an axial cross-sectional area that is less than the largest axial cross-sectional area associated with body section 208, i.e., the axial cross-sectional area associated with a distal end 222 of body section 208. In one embodiment, since intermediate section 210 and body section 208 have substantially circular cross-sectional areas, the diameter of intermediate section 210 is less than the diameter of distal end 222 of body section 208.
- Tip section 214 typically includes a distal portion 214a and a proximal portion 214b.
- Distal portion 214a generally has a rounded shape. In the described embodiment, distal portion 214a has an approximately hemispherical shape.
- Proximal portion 214b has a substantially cylindrical shape, although it should be appreciated that the shape of proximal portion 214b may vary widely. In some embodiments, tip section 214 may include only distal portion 214a.
- the dimensions associated with monopole antenna 202 may vary, depending upon the overall configuration of a catheter in which monopole antenna 202 is used. By way of example, the dimensions may vary in order to achieve electric field lines of a particular shape.
- body section 208 has a longitudinal length in the range of approximately 0.25 inches to approximately 0.4 inches, e.g., approximately 0.3 inches.
- the longitudinal length of intermediate section 210 may range from approximately 0.07 inches to approximately 0.10 inches, e.g., the longitudinal length of intermediate section 210 may be approximately 0.09 inches.
- the longitudinal length of tip section 214 may range from total length of approximately 0.08 inches to approximately 0.1 inches. In one embodiment, distal portion 214a of tip section 214 may have a longitudinal length of approximately 0.06 inches.
- monopole antenna 202 has diameters that may also be widely varied.
- body section 208 may have a tapered shape, e.g., a frusto-conical shape. Accordingly, the diameters along the longitudinal axis of body section 208 will generally vary.
- the proximal end 218 of body section 208 may have a diameter which ranges between approximately 0.025 inches to approximately 0.04 inches, while the distal end 222 of body section 208 may have a diameter which ranges from approximately 0.06 inches to approximately 0.08 inches. It should be appreciated that the ranges of diameters may vary widely depending upon the requirements of an overall catheter system.
- the diameter of intermediate section 210 may also be widely varied.
- the diameter of intermediate section 210 may be any suitable diameter that is less than or equal to the diameter of distal end 222 of body section 208.
- the diameter of intermediate section 210 is preferably less than the diameter of distal end 222 of body section 208, in order for a plug to be securely formed around body section 208, as previously mentioned.
- distal end 222 of body section 208 has a diameter which ranges between approximately 0.6 inches and approximately 0.8 inches
- intermediate section 210 may have a diameter which ranges between approximately 0.04 inches to approximately 0.06 inches.
- the diameter associated with tip section 214 may also vary.
- the diameter associated with proximal portion 214b is substantially the same as a diameter associated with distal portion 214a. That is, when proximal portion 214b is approximately cylindrical in shape, and distal portion 214a is substantially hemispherical in shape, the diameters of proximal portion 214b and distal portion 214a may be approximately the same. For instance, the diameters may be in the range of approximately 0.08 inches to approximately 0.1 inches, although it should be understood that the diameters may be widely varied.
- a monopole antenna such as monopole antenna 202 may be formed from substantially any conductive material.
- monopole antennas are preferably formed from materials with relatively high conductivity characteristics. Since catheters which include monopole antennas are typically arranged to be inserted into human bodies, the monopole antennas are further formed from biocompatible materials, or are coated with a conductive biocompatible material, e.g., silver or
- Monopole antenna 202 is shaped to enable a substantially elliptical electromagnetic field to be formed around antenna 202.
- Figure 3 a is a diagrammatic side view representation of a monopole antenna, shown with contour lines associated with the magnitude of an associated electric field, in accordance with an embodiment of the present invention.
- Contour lines 304 are shown with respect to field propagation at ninety degrees of a cycle.
- a cycle is a phase shift of 360 degrees.
- the number of cycles per second will generally vary depending upon the frequency that is being used, which often varies depending upon the needs of a particular system. By way of example, in one embodiment, at a frequency of approximately 2.45 GigaHertz (GHz), the number of cycles per second is approximately 2.45 x 10 9 .
- GHz GigaHertz
- contour lines 304 of the magnitude of an electric field have been shown, although it should be appreciated that many more contour lines 304 associated with the magnitude of an electric field will generally exist.
- the magnitude of an electric field generally varies with the distance from monopole antenna 202. Specifically, the magnitude of an electric field decreases as the distance from monopole antenna 202 increases. For example, the magnitude of the portion of the electric field represented by contour line 304a is greater than the magnitude of the portion of the electric field represented by contour line 304c.
- the output power associated with monopole antenna 202 is approximately one Watt (W)
- the magnitude of the electric field represented by contour line 304a is approximately 1000 Volts per meter (V/m).
- the magnitude of electric field line 304c may be approximately
- Ablation procedures that are performed with monopole antenna 202 may be more efficient than those performed using a conventional monopole antenna, in that the ablation of tissue is generally more even, e.g., the depth of an ablation made in cardiac tissue may be uniform.
- the tip-firing capabilities of monopole antenna 202, as well as the deep penetration of the energy which emanates from monopole antenna 202 may allow for a more efficient treatment of flutters and tachychardias, for example.
- Monopole antenna 202 has an associated specific abso ⁇ tion rate (SAR), as will be understood by those skilled in the art.
- Figure 3b is a diagrammatic side view representation of a monopole antenna, i.e., monopole antenna 302 of Figure 3a, shown with a pattern specific abso ⁇ tion rates, in accordance with an embodiment of the present invention.
- the specific abso ⁇ tion rate associated with an antenna may be expressed as follows:
- ⁇ is the associated electrical conductivity at a particular frequency, e.g.,
- E 2 is the square of the magnitude of the electric field.
- E 2 is the square of the magnitude of the electric field.
- the specific abso ⁇ tion rate As the magnitude of the electric field varies with distance from monopole antenna 202, the specific abso ⁇ tion rate also varies. Since the specific abso ⁇ tion rate is a function of the magnitude of the electric field, the specific abso ⁇ tion rate decreases as the distance from monopole antenna 202 increases.
- specific abso ⁇ tion rate 354a is the highest rate associated with monopole antenna 202, while specific abso ⁇ tion rate 354c is the lowest rate associated with monopole antenna 202.
- the pattern of specific abso ⁇ tion rates have been shown as including three rates 354, it should be appreciated that more rates generally exist although, in some embodiments, fewer rates may be in existence.
- FIG. 4 is a diagrammatic cross-sectional representation of a distal end of a catheter which includes a monopole antenna in accordance with an embodiment of the present invention.
- a distal end 400 of a catheter includes a monopole antenna 402 which has a tapered body section 408, an intermediate section 410, and a tip section 414.
- monopole antenna 402 also includes a surface finish 418, or coating, that covers the exterior of tip section 414.
- Surface finish 418 may be formed from a variety of different materials.
- surface finish 418 may be a silver plating. It should be appreciated that in another embodiment, monopole antenna 402 may not include a surface finish.
- monopole antenna 402 is coupled to an electromagnetic wave generator that is external to the catheter (not shown) through a coaxial cable 430.
- a center conductor 432 is electrically coupled to a proximal end of body section 408.
- body section 408 is bored out, e.g., includes a proximal bore 409, that is arranged to allow center conductor 432 to be electrically coupled to monopole antenna 402.
- center conductor 432 extends past an outer conductor 436, or a shield, of coaxial cable 430.
- a variety of different methods may be used to couple center conductor 432 to body section 408.
- center conductor 432 may be coupled to body section 408 using a crimping process.
- An inner dielectric 434 of coaxial cable 430 serves to separate center conductor 432, which is arranged to carry electrical current, from shield 436 of coaxial cable 430.
- outer conductor 436 is often used for grounding pu ⁇ oses.
- coaxial cable 430 is arranged to provide power to monopole antenna 402, it should be appreciated that substantially any transmission line may be used in lieu of coaxial cable 430.
- a flexible tubing 440 is effectively an outer sleeve that is formed over coaxial cable 430.
- flexible tubing 440 may be made from any flexible, biocompatible material including, but not limited to, Teflon, polyethylene, and polyurethane.
- the thickness of flexible tubing 440 may vary widely depending upon the requirements of a particular catheter. By way of example, the thickness of flexible tubing 440 may vary between approximately 0.005 inches and approximately 0.015 inches.
- Electrode bands 444 are often "pressed into” flexible tubing 440 such that electrode bands 444 may make contact with fluids and tissue that are external to the catheter.
- electrode bands are electrically coupled to an external power supply (not shown) through electrode wires 448 which are located between flexible tubing 440 and co-axial cable 430.
- Electrode bands 444 may be used to monitor electrocardiogram signals from a patient during an ablation procedure.
- electrode band 444b which is the electrode band which is most distally positioned with respect to distal end 400 of catheter, is substantially electrically coupled to outer conductor 436 through wires 462.
- Such a connection to outer conductor 436 is generally made as close to the distal end of outer conductor 436 as possible, as will be understood by those skilled in the art.
- electrode bands 444 may each have a width of approximately 0.004 inches, or approximately 1 millimeter, although the width of each electrode band 444 may vary.
- electrode bands 444 may be formed from substantially any suitable biocompatible, material including, but not limited to, stainless steel and iridium platinum. Typically, the location of electrode bands 444 is such that electrode bands 444 are relatively close to monopole antenna 402.
- a plug 460 which is formed around body section 408 and intermediate section 410 of monopole antenna 402, is arranged to hold monopole antenna 402 with respect to flexible tubing 440. Such a plug may be molded around at least a portion of monopole antenna 402 in order to hold monopole antenna 402.
- plug 460 may be formed from any suitable, preferably biocompatible, material, which is capable of withstanding electromagnetic fields that may be produced using monopole antenna 402.
- plug 460 may be formed from a material such as Teflon or polyethylene.
- the configuration of intermediate section 410, with respect to body section 408 and tip section 414, is arranged to hold plug 460 securely in place with respect to monopole antenna 402.
- an ablation catheter that includes a monopole antenna which generates a substantially deep electric field with respect to the monopole antenna has been generally described as being a microwave ablation catheter.
- a monopole antenna may be use with various other catheters including, but not limited, to catheters which operate using radio frequency waves.
- a monopole antenna has been described as being formed from a material such as stainless steel, it should be appreciated that materials used in the fabrication of a monopole antenna may vary widely.
- monopole antenna may be formed from substantially any material having a good electrical conductivity.
- the sections of a monopole antenna may take on various shapes without departing from the spirit or the scope of the present invention.
- the shape of the electric field which emanates from the monopole antenna may be varied.
- the body section of a monopole antenna may not have a tapered shape.
- varying the shapes associated with a monopole antenna may still enable the generated electric field to be substantially uniform.
- varying the shapes may result in the generation of relatively non-uniform electric fields.
- the generation of relatively non-uniform electric fields may be desirable, for instance, when a monopole antenna is to be used for an ablation procedure that requires a specifically shaped electric field. That is, the tip section, the intermediate section, and the body section of a monopole antenna may be shaped to provide electric fields of particular shapes as required for specific ablation procedures.
- a transmission line e.g., the center conductor of a co-axial cable
- a transmission line may be electrically coupled to the monopole antenna using various other methods, and at different locations with respect to the monopole antenna. Therefore, the present examples are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims.
Abstract
An ablation catheter apparatus with a monopole antenna that is arranged to provide a relatively uniform electric field and a method for using such an ablation catheter apparatus are disclosed. According to one aspect of the present invention, an ablation catheter includes an elongated flexible tubular member that is adapted to be inserted into the body of a patient, and a transmission line that is disposed within the tubular member. The transmission line has a distal end and a proximal end which is arranged to be connected to an electromagnetic energy source. The catheter also includes a monopole antenna with tip section and a body section that includes a distal end and a proximal end. The tip section and the body section are arranged to produce a relatively uniform electric field around the monopole antenna which is sufficiently strong to cause tissue ablation. The proximal end of the body section of the monopole antenna is arranged to be electrically coupled to the transmission line.
Description
MONOPOLE TIP FOR ABLATION CATHETER AND METHODS FOR USING
SAME
BACKGROUND OF THE INVENTION 1. Field of Invention
The present invention relates generally to ablation catheter systems that use electromagnetic energy in the microwave frequency range to ablate internal bodily tissues. More particularly, the present invention relates to a monopole tip for a catheter that enables distal fire capabilities while enabling a relatively even electromagnetic field to be created at the sides of the monopole tip to facilitate the ablation of cardiac tissue.
2. Description of the Related Art
Catheter ablation is a therapy that is becoming more widely used for the treatment of medical problems such as cardiac arrhythmias, cardiac disrhythmias, and tachycardia. Most presently approved ablation catheter systems utilize radio frequency (RF) energy as the ablating energy source. However, RF energy has several limitations which include the rapid dissipation of energy in surface tissues.
This rapid dissipation of energy often results in shallow "burns," as well as a failure to access deeper arrhythmic tissues. As such, catheters which utilize electromagnetic energy in the microwave frequency range as the ablation energy source are currently being developed. Microwave frequency energy has long been recognized as an effective energy source for heating biological tissues and has seen use in such hyperthermia applications as cancer treatment and the preheating of blood prior to infusions. Catheters which utilize microwave energy have been observed to be
capable of generating substantially larger lesions than those generated by RF catheters, which greatly simplifies the actual ablation procedures. Some catheter systems which utilize microwave energy are described in the U.S. Patent Numbers 4,641,649 to Walinsky; 5,246,438 to Langberg; 5,405,346 to Grundy, et al.; and 5,314,466 to Stern, et al., each of which is incorporated herein by reference in its entirety.
Cardiac arrhythmias, which may be treated using catheter ablation, are generally circuits, known as "arrhythmia circuits," which form within the chambers of the heart. As is known to those skilled in the art, arrhythmia circuits are abnormal electrical connections that may form in various areas of the heart. For example, arrhythmia circuits may form around veins and/or arteries which lead away from and to the heart. Cardiac arrhythmias may occur in any area of the heart where arrhythmia circuits are formed.
The catheters used for treatment of cardiac arrythmias, disrhythmias, and tachycardia may have a variety of different antenna configurations to create electromagnetic fields used in ablation. Some catheters have antennas that essentially protrude from the distal ends of the catheters. In other words, some catheters have antennas which form the distal tips of the catheters. A monopole antenna is typically configured to form the distal tip of a catheter.
Figure la is a diagrammatic representation of a distal end of a catheter with a monopole antenna at its tip. A distal end 102 of a catheter has a monopole antenna 108 at its tip. As shown, monopole antenna 108 has a rounded shape, and is coupled
to a center conductor 112 of a co-axial transmission line 116. Typically, monopole antenna 108 is formed from a metallic material. Distal end 102 of the catheter may also include electrodes 120, which may be used for mapping processes, that may be coupled to processing equipment (not shown) using ECG wires 122.
Monopole antenna 108 is often arranged to be used in ablating tissue. Center conductor 112 transmits energy, e.g., electromagnetic energy, to monopole antenna 108 to allow an electromagnetic field to be formed with respect to monopole antenna. Figure lb is a diagrammatic representation of a monopole antenna, i.e., monopole antenna 108 of Figure la, shown with electromagnetic field lines. Electromagnetic field lines 130 generally radiate from monopole antenna 108 in a substantially ellipsoidal pattern. Hence, near sides 134, "hot spots" 138 of electromagnetic energy are typically formed. Hot spots 138 are generally associated with the highest amounts of electromagnetic energy radiated by monopole antenna 108. The existence of hot spots 138 causes certain portions of a myocardium of heart, for example, such as those that are substantially contacted by a hot spot to be ablated more than other portions.
When an ablation procedure is performed using monopole antenna 108, the depth of cuts formed may not be uniform, since electromagnetic field lines 130 are not uniform. That is, the shape, or profile, of electromagnetic field lines 130 are such that when ablation is performed, the depth associated with the ablation may not be even. The lack of even depth in an ablation procedure may cause the ablation, e.g., an ablation in the myocardium of a heart, to be unsuccessful, as all of the cardiac tissue
may not be effectively ablated. Hence, the ablation procedure may have to be repeated, which is both time-consuming and inefficient.
Therefore, what is needed is a monopole antenna structure for use with an ablation catheter that efficiently allows tissue to be ablated. More specifically, what is desired is a monopole antenna structure that is capable of producing a relatively uniform field, e.g., electromagnetic field, a deep lesion, and a microwave power deposition at the tip of a catheter, i.e., a tip-firing catheter.
SUMMARY OF THE INVENTION
The present invention relates generally to an ablation catheter with a monopole antenna that is arranged to provide an electric field that is able to produce a deep lesion, e.g., in the myocardium or a heart, and has a tip-firing capability. According to one aspect of the present invention, an ablation catheter includes an elongated flexible tubular member that is adapted to be inserted into the body of a patient, and a transmission line that is disposed within the tubular member. The transmission line has a distal end and a proximal end which is arranged to be connected to an electromagnetic energy source. The catheter also includes a monopole antenna with tip section and a body section that includes a distal end and a proximal end. The tip section and the body section are arranged to produce a relatively uniform electric field around the monopole antenna which is sufficiently strong to cause deep tissue ablation. The proximal end of the body section of the monopole antenna is arranged to be electrically coupled to the transmission line.
In one embodiment, the transmission line is a coaxial cable, which has a center conductor and an outer conductor. In such an embodiment, the proximal end of the monopole antenna is arranged to be electrically coupled to the center conductor. In another embodiment, the body section of the monopole antenna is tapered such that the diameter at the proximal end of the body section of the monopole antenna is smaller than the diameter at the distal end of the body section of the monopole antenna.
According to another aspect of the present invention, an antenna structure arranged to be used in an ablation catheter has a longitudinal axis, and includes a body section with a first end and a second end, a tip section, and a transition section. The body section is sized such that the axial cross-sectional area about the longitudinal axis of the second end is smaller than the axial cross-sectional area about the longitudinal axis of the first end. The second end is arranged to be electrically coupled to a transmission line, and the body section is shaped to allow a relatively uniform electric field to be formed with respect to the antenna structure. The tip section has a proximal portion that has an axial cross-sectional area about the longitudinal axis which is greater than or approximately equal to the axial cross- sectional area of the first end, and the transition section is disposed between the proximal portion and the first end.
In one embodiment, the first end has a diameter that is greater than the diameter of the second end, and the proximal portion has a diameter that is greater than or equal to the diameter of the first end. In such an embodiment, the tip section may have a diameter that is less than the diameter of the first end.
In accordance with still another aspect of the present invention, a microwave ablation catheter includes an elongated flexible tubular member, which has a distal portion, a proximal portion, and a longitudinal catheter axis, and is adapted to be inserted into a vessel in the body of a patient. The microwave ablation catheter also includes a transmission line with a proximal end and a distal end. The transmission line is disposed within the tubular member, and the proximal end of the transmission line is suitable for connection to an electromagnetic energy source. A monopole antenna which is part of the microwave ablation catheter is coupled to the transmission line for generating an electric field sufficiently strong to cause tissue ablation, and includes a frusto-conically shaped emitting surface with an axis that is substantially parallel to the longitudinal catheter axis. In one embodiment, the monopole antenna further includes a rounded distal emitter surface. In such an embodiment, the antenna may also include a trough region between the frusto- conically shaped emitting surface and the distal emitter surface, as well as an encapsulating material that encapsulates the trough and frusto-conically shaped emitting surface such that the trough forms an anchor for the encapsulating material.
These and other advantages of the present invention will become apparent upon reading the following detailed descriptions and studying the various figures of the drawings.
DETAILED DESCRIPTION OF THE DRAWINGS
The invention may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which:
Figure la is a diagrammatic representation of a distal end of a catheter with a monopole tip.
Figure lb is a diagrammatic representation of a monopole antenna, i.e., monopole antenna 108 of Figure la, shown with electromagnetic field lines.
Figure 2a is a diagrammatic representation of an ablation catheter in accordance with an embodiment of the present invention. Figure 2b is a perspective representation of a monopole antenna with a tapered configuration, i.e., monopole antenna 202 of Figure 2a, in accordance with an embodiment of the present invention.
Figure 3a is a diagrammatic side view representation of a monopole antenna, shown with a contour plot of the magnitude of electric field lines, in accordance with an embodiment of the present invention.
Figure 3b is a diagrammatic side view representation of a monopole antenna, i.e., monopole antenna 302 of Figure 3a, shown with relative specific absorption rates, in accordance with an embodiment of the present invention.
Figure 4 is a diagrammatic cross-sectional representation of a distal end of a catheter which includes a monopole antenna in accordance with an embodiment of the present invention.
BRIEF DESCRIPTION OF THE EMBODIMENTS
When the electromagnetic field associated with an antenna in an ablation catheter is not uniform, the depth of an ablation formed in cardiac tissue using the catheter is often uneven. Ablation catheters with conventional monopole antennas generally do not emit uniform electric fields. Instead, the contour of electric field lines, as well as hot spots in the electric field around a monopole antenna, are such that ablation of cardiac tissue, as for example in a myocardium of a heart, are often uneven. As a result, the ablation of the tissue may not be successful.
An ablation catheter that has a monopole antenna which is shaped to enable a substantially uniform field, e.g., electromagnetic or electric field, to be formed around the monopole antenna allows the depth of an ablation of tissue to occur substantially uniformly In addition, such a monopole antenna allows the catheter to have forward firing, or tip-firing, capabilities. That is, the distal tip of the monopole antenna may also be used to ablate tissue.
When the depth of an ablation is relatively uniform, i.e., has a substantially uniform depth, an overall ablation process may be more efficiently performed, as it may be unnecessary to repeatedly ablate the same area of tissue to obtain an even depth of ablation. When an overall ablation process is more efficient, in that the time spent performing ablation may be reduced.
A monopole antenna which includes a tip section and a tapered body section enables hot spots in the electromagnetic field formed around the body section to be substantially eliminated. Figure 2a is a diagrammatic representation of an ablation
catheter with a monopole antenna, which includes a tip section and a tapered body section, in accordance with an embodiment of the present invention. An ablation catheter 180, which is suitable for use as a microwave ablation catheter, is generally arranged to be introduced into the body of a patient through a blood vessel, e.g., the femoral vein. Catheter 180 may be considered to be an overall elongated, flexible, tube. It should be appreciated that for ease of illustration, catheter 180 has not been drawn to scale.
Since catheter 180 is arranged to be used within the body of a patient, materials used to form catheter 180 are typically biocompatible materials. Suitable biocompatible materials used to form catheter 180 include, but are not limited to medical grade polyolefins, fluoropolymers, polyurethane, polyethylene, or polyvinylidene fluoride. In one embodiment, a PEBAX resin, which is available commercially from Elf Atochem of Germany, may be used in the formation of catheter 180.
Catheter 180 includes a monopole antenna 202 from which an electric field may be emitted to cause ablation. As shown, monopole antenna 202 is located at the distal end of catheter 180. Monopole antenna 202, which may be machined from a material such as stainless steel using a mill or a lathe, will be discussed below with reference to Figure 2b. Typically, once catheter 180 is introduced into the body of a patient, catheter 180 is manipulated through a blood vessel and into the heart such that monopole antenna 202 may be positioned within a cardiac chamber in which an ablation procedure is to be performed.
Catheter 180 also includes electrodes 204 which are positioned on catheter 180 such that they are located proximally with respect to monopole antenna 202. Electrodes 204 are generally arranged to detect electro-physiological signals from cardiac tissue. Hence, electrodes 204, which are generally electrode bands, may be used to map the relevant region of the heart, i.e., the portion of the heart with which an ablation procedure is associated, prior to or after an ablation procedure. Electrodes 204 may also be used to aid in positioning catheter 180 during an ablation procedure. In general, although electrodes 204 may be formed from any suitable material which has biocompatible characteristics, electrodes 204 are typically formed from materials which include, but are not limited to, stainless steel and iridium platinum.
A handle 205 is often located near a proximal end of catheter 180, although it should be appreciated that handle 205 is not necessarily included as a part of catheter 180. Handle 205 is arranged to enable a user, i.e., an individual who is performing an ablation procedure on a patient, to grip and to manipulate catheter 180. In the described embodiment, a connector 206 is located on catheter 180 such that connector 206 is proximal to handle 205. Connector 206 is arranged to couple a transmission line (not shown), which is located within catheter 180, to a power supply, or similar device, that is designed to generate controlled electromagnetic energy.
As mentioned above, monopole antenna 202 is arranged to provide an electric field, e.g., an electromagnetic field, to allow tissue to be ablated. In the described embodiment, monopole antenna 202 is shaped such that the electric field which is generated is effectively confined to the monopole region associated with monopole antenna 202. With reference to Figure 2b, a monopole antenna with a tapered body
section will be described in accordance with an embodiment of the present invention. Figure 2b is a perspective representation of monopole antenna 202 of Figure 2a. Monopole antenna 202 includes a body section 208, an intermediate section 210, and a tip section 214. In the described embodiment, body section 208 has a tapered shape, e.g., body section 208 is shaped substantially as a conical structure with no single apex point. That is, body section 208, which includes an emitting surface, may have a frusto-conical shape. A proximal end 218 of body section 208 generally has the smallest axial cross-sectional area, about a longitudinal axis of monopole antenna 202, associated with body section 208. By way of example, the diameter of proximal end 218, about the longitudinal axis of monopole antenna 202, is typically smaller than any other diameter, along the same axis, that is associated with body section 208.
Intermediate section 210 effectively separates body section 208 from tip section 214. One purpose of intermediate, or "trough," section 210 is to allow a material which is used to encase body section 208 to be anchored with respect to monopole antenna 202. In other words, intermediate section 210 is shaped such that a material which effectively encapsulates body section 208 and, further, at least part of intermediate section 210, is generally prevented from "peeling away" from intermediate section 210 and body section 208. The encapsulating material serves as a plug that holds monopole antenna 202 against a catheter, e.g. , catheter 180 of Figure 2a. In general, any suitable material may be used to form a plug that essentially encases body section 208. Such materials include, but are not limited to, Teflon, such as PolyTetraFluoroEthylene (PTFE), and Polyethylene (PE).
As shown, intermediate section 210 has an axial cross-sectional area that is less than the largest axial cross-sectional area associated with body section 208, i.e., the axial cross-sectional area associated with a distal end 222 of body section 208. In one embodiment, since intermediate section 210 and body section 208 have substantially circular cross-sectional areas, the diameter of intermediate section 210 is less than the diameter of distal end 222 of body section 208.
Tip section 214 typically includes a distal portion 214a and a proximal portion 214b. Distal portion 214a generally has a rounded shape. In the described embodiment, distal portion 214a has an approximately hemispherical shape. Proximal portion 214b has a substantially cylindrical shape, although it should be appreciated that the shape of proximal portion 214b may vary widely. In some embodiments, tip section 214 may include only distal portion 214a.
Generally, the dimensions associated with monopole antenna 202 may vary, depending upon the overall configuration of a catheter in which monopole antenna 202 is used. By way of example, the dimensions may vary in order to achieve electric field lines of a particular shape. Typically, body section 208 has a longitudinal length in the range of approximately 0.25 inches to approximately 0.4 inches, e.g., approximately 0.3 inches. The longitudinal length of intermediate section 210 may range from approximately 0.07 inches to approximately 0.10 inches, e.g., the longitudinal length of intermediate section 210 may be approximately 0.09 inches. Finally, the longitudinal length of tip section 214 may range from total length of approximately 0.08 inches to approximately 0.1 inches. In one embodiment, distal
portion 214a of tip section 214 may have a longitudinal length of approximately 0.06 inches.
In addition to having a longitudinal length that may vary, monopole antenna 202 has diameters that may also be widely varied. As discussed above, body section 208 may have a tapered shape, e.g., a frusto-conical shape. Accordingly, the diameters along the longitudinal axis of body section 208 will generally vary. For example, the proximal end 218 of body section 208 may have a diameter which ranges between approximately 0.025 inches to approximately 0.04 inches, while the distal end 222 of body section 208 may have a diameter which ranges from approximately 0.06 inches to approximately 0.08 inches. It should be appreciated that the ranges of diameters may vary widely depending upon the requirements of an overall catheter system.
The diameter of intermediate section 210 may also be widely varied. In general, the diameter of intermediate section 210 may be any suitable diameter that is less than or equal to the diameter of distal end 222 of body section 208. However, the diameter of intermediate section 210 is preferably less than the diameter of distal end 222 of body section 208, in order for a plug to be securely formed around body section 208, as previously mentioned. By way of example, when distal end 222 of body section 208 has a diameter which ranges between approximately 0.6 inches and approximately 0.8 inches, then intermediate section 210 may have a diameter which ranges between approximately 0.04 inches to approximately 0.06 inches.
Like the other diameters associated with monopole antenna 202, the diameter associated with tip section 214 may also vary. In the described embodiment, the diameter associated with proximal portion 214b is substantially the same as a diameter associated with distal portion 214a. That is, when proximal portion 214b is approximately cylindrical in shape, and distal portion 214a is substantially hemispherical in shape, the diameters of proximal portion 214b and distal portion 214a may be approximately the same. For instance, the diameters may be in the range of approximately 0.08 inches to approximately 0.1 inches, although it should be understood that the diameters may be widely varied.
A monopole antenna such as monopole antenna 202 may be formed from substantially any conductive material. In general, monopole antennas are preferably formed from materials with relatively high conductivity characteristics. Since catheters which include monopole antennas are typically arranged to be inserted into human bodies, the monopole antennas are further formed from biocompatible materials, or are coated with a conductive biocompatible material, e.g., silver or
platinum.
Monopole antenna 202, as mentioned above, is shaped to enable a substantially elliptical electromagnetic field to be formed around antenna 202. Figure 3 a is a diagrammatic side view representation of a monopole antenna, shown with contour lines associated with the magnitude of an associated electric field, in accordance with an embodiment of the present invention. Contour lines 304 are shown with respect to field propagation at ninety degrees of a cycle. As will be appreciated by those skilled in the art, a cycle is a phase shift of 360 degrees. The
number of cycles per second will generally vary depending upon the frequency that is being used, which often varies depending upon the needs of a particular system. By way of example, in one embodiment, at a frequency of approximately 2.45 GigaHertz (GHz), the number of cycles per second is approximately 2.45 x 109.
For purposes of illustration, representative contour lines 304 of the magnitude of an electric field have been shown, although it should be appreciated that many more contour lines 304 associated with the magnitude of an electric field will generally exist. The magnitude of an electric field generally varies with the distance from monopole antenna 202. Specifically, the magnitude of an electric field decreases as the distance from monopole antenna 202 increases. For example, the magnitude of the portion of the electric field represented by contour line 304a is greater than the magnitude of the portion of the electric field represented by contour line 304c. In the described embodiment, the output power associated with monopole antenna 202 is approximately one Watt (W), and the magnitude of the electric field represented by contour line 304a is approximately 1000 Volts per meter (V/m). In such an embodiment, the magnitude of electric field line 304c may be approximately
500 V/m.
Ablation procedures that are performed with monopole antenna 202 may be more efficient than those performed using a conventional monopole antenna, in that the ablation of tissue is generally more even, e.g., the depth of an ablation made in cardiac tissue may be uniform. Specifically, the tip-firing capabilities of monopole antenna 202, as well as the deep penetration of the energy which emanates from
monopole antenna 202, may allow for a more efficient treatment of flutters and tachychardias, for example.
Monopole antenna 202 has an associated specific absoφtion rate (SAR), as will be understood by those skilled in the art. Figure 3b is a diagrammatic side view representation of a monopole antenna, i.e., monopole antenna 302 of Figure 3a, shown with a pattern specific absoφtion rates, in accordance with an embodiment of the present invention. The specific absoφtion rate associated with an antenna may be expressed as follows:
SAR = —
2
where σ is the associated electrical conductivity at a particular frequency, e.g.,
approximately 2.45 GHz, and E2 is the square of the magnitude of the electric field. As the magnitude of the electric field varies with distance from monopole antenna 202, the specific absoφtion rate also varies. Since the specific absoφtion rate is a function of the magnitude of the electric field, the specific absoφtion rate decreases as the distance from monopole antenna 202 increases.
In the described embodiment, specific absoφtion rate 354a is the highest rate associated with monopole antenna 202, while specific absoφtion rate 354c is the lowest rate associated with monopole antenna 202. The pattern of specific absoφtion rates have been shown as including three rates 354, it should be appreciated that more rates generally exist although, in some embodiments, fewer rates may be in existence.
Figure 4 is a diagrammatic cross-sectional representation of a distal end of a catheter which includes a monopole antenna in accordance with an embodiment of the
present invention. A distal end 400 of a catheter includes a monopole antenna 402 which has a tapered body section 408, an intermediate section 410, and a tip section 414. For illustrative ptuposes, distal end 400 of catheter has not been drawn to scale. In the embodiment as shown, monopole antenna 402 also includes a surface finish 418, or coating, that covers the exterior of tip section 414. Surface finish 418 may be formed from a variety of different materials. By way of example, surface finish 418 may be a silver plating. It should be appreciated that in another embodiment, monopole antenna 402 may not include a surface finish.
In the described embodiment, monopole antenna 402 is coupled to an electromagnetic wave generator that is external to the catheter (not shown) through a coaxial cable 430. Specifically, a center conductor 432 is electrically coupled to a proximal end of body section 408. As shown, body section 408 is bored out, e.g., includes a proximal bore 409, that is arranged to allow center conductor 432 to be electrically coupled to monopole antenna 402. In order to facilitate coupling of center conductor 432 to body section 408, center conductor 432 extends past an outer conductor 436, or a shield, of coaxial cable 430. A variety of different methods may be used to couple center conductor 432 to body section 408. By way of example, center conductor 432 may be coupled to body section 408 using a crimping process. An inner dielectric 434 of coaxial cable 430 serves to separate center conductor 432, which is arranged to carry electrical current, from shield 436 of coaxial cable 430. As will be appreciated by those skilled in the art, outer conductor 436 is often used for grounding puφoses. Although coaxial cable 430 is arranged to provide power to monopole antenna 402, it should be appreciated that substantially any transmission line may be used in lieu of coaxial cable 430.
A flexible tubing 440, is effectively an outer sleeve that is formed over coaxial cable 430. Typically, flexible tubing 440 may be made from any flexible, biocompatible material including, but not limited to, Teflon, polyethylene, and polyurethane. The thickness of flexible tubing 440 may vary widely depending upon the requirements of a particular catheter. By way of example, the thickness of flexible tubing 440 may vary between approximately 0.005 inches and approximately 0.015 inches.
Electrode bands 444 are often "pressed into" flexible tubing 440 such that electrode bands 444 may make contact with fluids and tissue that are external to the catheter. In general, electrode bands are electrically coupled to an external power supply (not shown) through electrode wires 448 which are located between flexible tubing 440 and co-axial cable 430. Electrode bands 444 may be used to monitor electrocardiogram signals from a patient during an ablation procedure. As shown, electrode band 444b, which is the electrode band which is most distally positioned with respect to distal end 400 of catheter, is substantially electrically coupled to outer conductor 436 through wires 462. Such a connection to outer conductor 436 is generally made as close to the distal end of outer conductor 436 as possible, as will be understood by those skilled in the art.
In one embodiment, electrode bands 444 may each have a width of approximately 0.004 inches, or approximately 1 millimeter, although the width of each electrode band 444 may vary. As previously mentioned, electrode bands 444 may be formed from substantially any suitable biocompatible, material including, but
not limited to, stainless steel and iridium platinum. Typically, the location of electrode bands 444 is such that electrode bands 444 are relatively close to monopole antenna 402.
A plug 460, which is formed around body section 408 and intermediate section 410 of monopole antenna 402, is arranged to hold monopole antenna 402 with respect to flexible tubing 440. Such a plug may be molded around at least a portion of monopole antenna 402 in order to hold monopole antenna 402. As discussed above, plug 460 may be formed from any suitable, preferably biocompatible, material, which is capable of withstanding electromagnetic fields that may be produced using monopole antenna 402. By way of example, plug 460 may be formed from a material such as Teflon or polyethylene. The configuration of intermediate section 410, with respect to body section 408 and tip section 414, is arranged to hold plug 460 securely in place with respect to monopole antenna 402.
Although only a few embodiments of the present invention have been described, it should be understood that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the present invention. By way of example, an ablation catheter that includes a monopole antenna which generates a substantially deep electric field with respect to the monopole antenna has been generally described as being a microwave ablation catheter. However, such a monopole antenna may be use with various other catheters including, but not limited, to catheters which operate using radio frequency waves.
While a monopole antenna has been described as being formed from a material such as stainless steel, it should be appreciated that materials used in the fabrication of a monopole antenna may vary widely. In general, monopole antenna may be formed from substantially any material having a good electrical conductivity.
The sections of a monopole antenna, namely, the tip section, the intermediate section, and the body section, may take on various shapes without departing from the spirit or the scope of the present invention. By varying the shapes of the different sections, the shape of the electric field which emanates from the monopole antenna may be varied. For example, in one embodiment, the body section of a monopole antenna may not have a tapered shape. In some cases, varying the shapes associated with a monopole antenna may still enable the generated electric field to be substantially uniform. In other cases, varying the shapes may result in the generation of relatively non-uniform electric fields. The generation of relatively non-uniform electric fields may be desirable, for instance, when a monopole antenna is to be used for an ablation procedure that requires a specifically shaped electric field. That is, the tip section, the intermediate section, and the body section of a monopole antenna may be shaped to provide electric fields of particular shapes as required for specific ablation procedures.
A transmission line, e.g., the center conductor of a co-axial cable, has generally been described as being crimped, or otherwise coupled, to the proximal end of a monopole antenna. It should be appreciated that a transmission line may be electrically coupled to the monopole antenna using various other methods, and at different locations with respect to the monopole antenna. Therefore, the present
examples are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims.
Claims
What is claimed is:
1. An ablation catheter comprising: an elongated flexible tubular member, the elongated flexible tubular member being arranged to be inserted into the body of a patient; a transmission line disposed within the tubular member, the transmission line having a distal end and a proximal end, wherein the proximal end of the transmission line is suitable for connection to an electromagnetic energy source; and a monopole antenna, the monopole antenna having a tip section and a body section, the body section including a distal end and a proximal end, the tip section and the body section being arranged to produce a relatively uniform electric field around the monopole antenna, the relatively uniform electric field being sufficiently strong to cause tissue ablation, wherein the proximal end of the body section of the monopole antenna is arranged to be electrically coupled to the transmission line.
2. An ablation catheter according to claim 1 wherein the transmission line is a coaxial transmission line, the coaxial transmission line having a center conductor and an outer conductor, wherein the proximal end of the monopole antenna is arranged to be electrically coupled to the center conductor.
3. An ablation catheter according to claim 1 wherein the body section of the monopole antenna is tapered such that a diameter at the proximal end of the body section of the monopole antenna is smaller than a diameter at the distal end of the body section of the monopole antenna.
4. An ablation catheter according to claim 3 wherein the tip section of the monopole antenna includes a first portion and a second portion, the first portion of the tip section of the monopole antenna having a diameter that is greater than or equal to the diameter at the distal end of the body section of the monopole antenna.
5. An ablation catheter according to claim 4 wherein the second portion of the tip section of the monopole antenna is substantially hemispherical in shape.
6. An ablation catheter according to claim 5 wherein the monopole antenna further includes an intermediate section, the intermediate section being disposed between the tip section of the monopole antenna and the body section of the monopole antenna.
7. An ablation catheter according to claim 6 wherein the intermediate section of the monopole antenna has a diameter that is less than the diameter of the distal end of the body section of the monopole antenna.
8. An ablation catheter according to claim 6 wherein the second portion of the tip section of the monopole antenna, the intermediate section of the monopole antenna, and the body section of the monopole antenna are substantially encased in a biocompatible material, wherein the intermediate section of the monopole antenna is arranged to anchor the biocompatible material.
9. An ablation catheter according to claim 8 wherein the biocompatible material is Teflon.
10. An ablation catheter according to claim 1 further including: an electrode, the electrode being located on the elongated flexible tubular member proximal to the monopole antenna, wherein the electrode is arranged to detect electro-physiological signals.
11. An ablation catheter according to claim 1 wherein the monopole antenna is formed from stainless steel.
13. An antenna structure arranged to be used in an ablation catheter, the antenna structure having a longitudinal axis therethrough, the antenna structure comprising: a body section, the body section having a first end and a second end, the body section being sized such that an axial cross-sectional area about the longitudinal axis of the second end is smaller than an axial cross-sectional area about the longitudinal axis of the first end, the second end being arranged to be electrically coupled to a transmission line, wherein the body section is shaped to allow a relatively uniform electric field to be formed with respect to the antenna structure; a tip section, the tip section having a proximal portion that has an axial cross- sectional area about the longitudinal axis that is greater than or approximately equal to the axial cross-sectional area of the first end; and a transition section, the transition section being disposed between the proximal
portion and the first end.
14. An antenna structure according to claim 13 wherein the first end has a diameter that is greater than the diameter of the second end, and the proximal portion has a diameter that is greater than or equal to the diameter of the first end.
15. An antenna structure according to claim 14 wherein the tip section has a diameter that is less than the diameter of the first end.
16. An antenna structure according to claim 13 wherein the antenna structure is formed from stainless steel.
17. An antenna structure according to claim 16 wherein the tip section is coated with a surface finish.
18. An antenna structure according to claim 17 wherein the surface finish is at least partially formed from silver.
19. An antenna structure according to claim 13 wherein the body section is substantially conically shaped.
20. A method for medical treatment using an ablation catheter system that includes a catheter having a transmission line disposed within a flexible tubular member and a monopole antenna coupled to the transmission line for generating a substantially uniform electric field sufficiently strong to cause tissue ablation, the monopole antenna being located at a distal tip portion of the catheter, the monopole
antenna being arranged to generate the substantially uniform electric field about the distal tip portion of the catheter, the method comprising: introducing the catheter into a first vessel of the body of a patient and into the heart of the patient such that the distal tip portion of the catheter is positioned within a cardiac chamber of the heart of the body of the patient; applying electromagnetic energy to the transmission line to generate a substantially uniform electric field about the distal tip portion of the catheter; and ablating cardiac tissue in a region adjacent to the distal tip portion of the catheter using the substantially uniform electric field generated about the distal tip portion of the catheter.
21. A method for medical treatment as recited in claim 20 wherein the monopole antenna includes a tip section, an intermediate section, and a tapered body section, and applying electromagnetic energy to the transmission line to generate the substantially uniform electric field about the distal tip portion of the catheter includes generating the substantially uniform electric field about the tip section and the tapered body section.
22. A microwave ablation catheter comprising: an elongated flexible tubular member adapted to be inserted into a vessel in the body of a patient, the flexible tubular member including a distal portion, a proximal portion and a longitudinal catheter axis; a transmission line disposed within the tubular member, the transmission line having proximal and distal ends, wherein the proximal end of the transmission line is suitable for connection to an electromagnetic energy source;
a monopole antenna coupled to the transmission line for generating an electric field sufficiently strong to cause tissue ablation, the monopole antenna including a frusto-conically shaped emitting surface having an axis that is substantially parallel to the longitudinal catheter axis.
23. A microwave ablation catheter as recited in claim 22 wherein the antenna further includes a rounded distal emitter surface.
24. A microwave ablation catheter as recited in claim 23 wherein: the antenna further includes a trough region between the frusto-conically shaped emitting surface and the distal emitter surface; and an encapsulating material that encapsulates the trough and frusto-conically shaped emitting surface, whereby the trough forms an anchor for the encapsulating
material.
25. A microwave ablation catheter as recited in claim 22 wherein the antenna further includes a proximal bore for receiving the transmission line.
26. A microwave ablation catheter as recited in claim 22 wherein the diameter of the frusto-conically shaped emitting surface of the antenna is narrowest on its proximal end.
27. A microwave ablation catheter as recited in claim 22 wherein the length of the frusto-conically shaped emitting surface of the antenna is in the range of approximately 0.25 inches to approximately 0.4 inches.
28. A microwave ablation catheter as recited in claim 22 wherein the diameter of the frusto-conically shaped emitting surface of the antenna is in the range of approximately 0.025 inches to approximately 0.08 inches.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP00932818A EP1189542A1 (en) | 1999-05-28 | 2000-05-30 | Monopole tip for ablation catheter and methods for using same |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/321,666 | 1999-05-28 | ||
US09/321,666 US6277113B1 (en) | 1999-05-28 | 1999-05-28 | Monopole tip for ablation catheter and methods for using same |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2001001876A1 true WO2001001876A1 (en) | 2001-01-11 |
Family
ID=23251503
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2000/014953 WO2001001876A1 (en) | 1999-05-28 | 2000-05-30 | Monopole tip for ablation catheter and methods for using same |
Country Status (3)
Country | Link |
---|---|
US (4) | US6277113B1 (en) |
EP (1) | EP1189542A1 (en) |
WO (1) | WO2001001876A1 (en) |
Families Citing this family (99)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20070066972A1 (en) * | 2001-11-29 | 2007-03-22 | Medwaves, Inc. | Ablation catheter apparatus with one or more electrodes |
US6277113B1 (en) | 1999-05-28 | 2001-08-21 | Afx, Inc. | Monopole tip for ablation catheter and methods for using same |
US6306132B1 (en) | 1999-06-17 | 2001-10-23 | Vivant Medical | Modular biopsy and microwave ablation needle delivery apparatus adapted to in situ assembly and method of use |
US6878147B2 (en) | 2001-11-02 | 2005-04-12 | Vivant Medical, Inc. | High-strength microwave antenna assemblies |
US7128739B2 (en) | 2001-11-02 | 2006-10-31 | Vivant Medical, Inc. | High-strength microwave antenna assemblies and methods of use |
JP2005511135A (en) * | 2001-11-29 | 2005-04-28 | メッドウェイブズ、インコーポレイテッド | High frequency based catheter system with improved deflection and steering mechanisms |
US6817999B2 (en) | 2002-01-03 | 2004-11-16 | Afx, Inc. | Flexible device for ablation of biological tissue |
US7099717B2 (en) | 2002-01-03 | 2006-08-29 | Afx Inc. | Catheter having improved steering |
US6893436B2 (en) | 2002-01-03 | 2005-05-17 | Afx, Inc. | Ablation instrument having a flexible distal portion |
US7197363B2 (en) | 2002-04-16 | 2007-03-27 | Vivant Medical, Inc. | Microwave antenna having a curved configuration |
US6752767B2 (en) | 2002-04-16 | 2004-06-22 | Vivant Medical, Inc. | Localization element with energized tip |
EP1617776B1 (en) | 2003-05-01 | 2015-09-02 | Covidien AG | System for programing and controlling an electrosurgical generator system |
US7311703B2 (en) | 2003-07-18 | 2007-12-25 | Vivant Medical, Inc. | Devices and methods for cooling microwave antennas |
US7244254B2 (en) * | 2004-04-29 | 2007-07-17 | Micrablate | Air-core microwave ablation antennas |
US20060276781A1 (en) * | 2004-04-29 | 2006-12-07 | Van Der Weide Daniel W | Cannula cooling and positioning device |
US7467015B2 (en) | 2004-04-29 | 2008-12-16 | Neuwave Medical, Inc. | Segmented catheter for tissue ablation |
EP1846873B1 (en) * | 2004-12-22 | 2009-03-25 | Precimed S.A. | Intelligent implement having metal encased passive radio frequency transponder and examples of use |
US7156570B2 (en) * | 2004-12-30 | 2007-01-02 | Cotapaxi Custom Design And Manufacturing, Llc | Implement grip |
US7799019B2 (en) | 2005-05-10 | 2010-09-21 | Vivant Medical, Inc. | Reinforced high strength microwave antenna |
US8932208B2 (en) | 2005-05-26 | 2015-01-13 | Maquet Cardiovascular Llc | Apparatus and methods for performing minimally-invasive surgical procedures |
WO2006138382A2 (en) | 2005-06-14 | 2006-12-28 | Micrablate, Llc | Microwave tissue resection tool |
WO2007112102A1 (en) | 2006-03-24 | 2007-10-04 | Micrablate | Center fed dipole for use with tissue ablation systems, devices, and methods |
EP1998699A1 (en) * | 2006-03-24 | 2008-12-10 | Neuwave Medical, Inc. | Energy delivery system |
WO2007112081A1 (en) | 2006-03-24 | 2007-10-04 | Micrablate | Transmission line with heat transfer ability |
US10376314B2 (en) | 2006-07-14 | 2019-08-13 | Neuwave Medical, Inc. | Energy delivery systems and uses thereof |
CN102784007B (en) | 2006-07-14 | 2015-09-30 | 纽华沃医药公司 | Energy transmission system and uses thereof |
US11389235B2 (en) | 2006-07-14 | 2022-07-19 | Neuwave Medical, Inc. | Energy delivery systems and uses thereof |
US8068921B2 (en) | 2006-09-29 | 2011-11-29 | Vivant Medical, Inc. | Microwave antenna assembly and method of using the same |
US7998139B2 (en) | 2007-04-25 | 2011-08-16 | Vivant Medical, Inc. | Cooled helical antenna for microwave ablation |
US8353901B2 (en) | 2007-05-22 | 2013-01-15 | Vivant Medical, Inc. | Energy delivery conduits for use with electrosurgical devices |
US9023024B2 (en) | 2007-06-20 | 2015-05-05 | Covidien Lp | Reflective power monitoring for microwave applications |
US9861424B2 (en) | 2007-07-11 | 2018-01-09 | Covidien Lp | Measurement and control systems and methods for electrosurgical procedures |
US8152800B2 (en) | 2007-07-30 | 2012-04-10 | Vivant Medical, Inc. | Electrosurgical systems and printed circuit boards for use therewith |
US7645142B2 (en) | 2007-09-05 | 2010-01-12 | Vivant Medical, Inc. | Electrical receptacle assembly |
US8747398B2 (en) | 2007-09-13 | 2014-06-10 | Covidien Lp | Frequency tuning in a microwave electrosurgical system |
US8651146B2 (en) | 2007-09-28 | 2014-02-18 | Covidien Lp | Cable stand-off |
EP2209517A4 (en) | 2007-10-05 | 2011-03-30 | Maquet Cardiovascular Llc | Devices and methods for minimally-invasive surgical procedures |
US8292880B2 (en) | 2007-11-27 | 2012-10-23 | Vivant Medical, Inc. | Targeted cooling of deployable microwave antenna |
AU2009220201B2 (en) * | 2008-03-04 | 2013-06-20 | Cardiac Pacemakers, Inc. | Loaded RF antenna for implantable device |
US8972021B2 (en) * | 2008-03-04 | 2015-03-03 | Cardiac Pacemakers, Inc. | Detachable helical antenna for implantable medical device |
US8059059B2 (en) * | 2008-05-29 | 2011-11-15 | Vivant Medical, Inc. | Slidable choke microwave antenna |
US8728068B2 (en) * | 2009-04-09 | 2014-05-20 | Urologix, Inc. | Cooled antenna for device insertable into a body |
US9226791B2 (en) | 2012-03-12 | 2016-01-05 | Advanced Cardiac Therapeutics, Inc. | Systems for temperature-controlled ablation using radiometric feedback |
US9277961B2 (en) | 2009-06-12 | 2016-03-08 | Advanced Cardiac Therapeutics, Inc. | Systems and methods of radiometrically determining a hot-spot temperature of tissue being treated |
US8954161B2 (en) | 2012-06-01 | 2015-02-10 | Advanced Cardiac Therapeutics, Inc. | Systems and methods for radiometrically measuring temperature and detecting tissue contact prior to and during tissue ablation |
US8926605B2 (en) | 2012-02-07 | 2015-01-06 | Advanced Cardiac Therapeutics, Inc. | Systems and methods for radiometrically measuring temperature during tissue ablation |
EP2859862B1 (en) | 2009-07-28 | 2017-06-14 | Neuwave Medical, Inc. | Ablation system |
US8469953B2 (en) | 2009-11-16 | 2013-06-25 | Covidien Lp | Twin sealing chamber hub |
EP2528575B1 (en) * | 2010-01-28 | 2016-04-27 | ART Healthcare Ltd. | Device of detecting and/or blocking reflux |
US20110213353A1 (en) | 2010-02-26 | 2011-09-01 | Lee Anthony C | Tissue Ablation System With Internal And External Radiation Sources |
EP2549974B1 (en) | 2010-03-22 | 2016-10-26 | ART Healthcare Ltd. | Naso/orogastric tube having one or more backflow blocking elements, backflow blocking elements, and a method of using backflow blocking elements |
US9011426B2 (en) | 2010-04-22 | 2015-04-21 | Electromedical Associates, Llc | Flexible electrosurgical ablation and aspiration electrode with beveled active surface |
US9643255B2 (en) | 2010-04-22 | 2017-05-09 | Electromedical Associates, Llc | Flexible electrosurgical ablation and aspiration electrode with beveled active surface |
JP6153865B2 (en) | 2010-05-03 | 2017-06-28 | ニューウェーブ メディカル, インコーポレイテッドNeuwave Medical, Inc. | Energy delivery system |
US9241762B2 (en) | 2010-06-03 | 2016-01-26 | Covidien Lp | Specific absorption rate measurement and energy-delivery device characterization using image analysis |
US9377367B2 (en) | 2010-06-03 | 2016-06-28 | Covidien Lp | Specific absorption rate measurement and energy-delivery device characterization using thermal phantom and image analysis |
US9468492B2 (en) | 2010-06-03 | 2016-10-18 | Covidien Lp | Specific absorption rate measurement and energy-delivery device characterization using image analysis |
US8188435B2 (en) | 2010-06-03 | 2012-05-29 | Tyco Healthcare Group Lp | Specific absorption rate measurement and energy-delivery device characterization using thermal phantom and image analysis |
US10765473B2 (en) | 2010-11-08 | 2020-09-08 | Baylis Medical Company Inc. | Electrosurgical device having a lumen |
CA2845795A1 (en) | 2011-04-08 | 2013-07-18 | Covidien Lp | Flexible microwave catheters for natural or artificial lumens |
US9265958B2 (en) | 2011-04-29 | 2016-02-23 | Cyberonics, Inc. | Implantable medical device antenna |
US9240630B2 (en) | 2011-04-29 | 2016-01-19 | Cyberonics, Inc. | Antenna shield for an implantable medical device |
US9089712B2 (en) | 2011-04-29 | 2015-07-28 | Cyberonics, Inc. | Implantable medical device without antenna feedthrough |
US9259582B2 (en) | 2011-04-29 | 2016-02-16 | Cyberonics, Inc. | Slot antenna for an implantable device |
GB201121436D0 (en) | 2011-12-14 | 2012-01-25 | Emblation Ltd | A microwave applicator and method of forming a microwave applicator |
JP2015503963A (en) | 2011-12-21 | 2015-02-05 | ニューウェーブ メディカル, インコーポレイテッドNeuwave Medical, Inc. | Energy supply system and method of use thereof |
WO2013123089A1 (en) * | 2012-02-17 | 2013-08-22 | Cohen Nathaniel L | Apparatus for using microwave energy for insect and pest control and methods thereof |
JP6242884B2 (en) | 2012-06-22 | 2017-12-06 | コビディエン エルピー | Microwave temperature measurement for microwave ablation system |
WO2014008508A1 (en) | 2012-07-06 | 2014-01-09 | The Ohio State University | Compact dual band gnss antenna design |
US9044254B2 (en) | 2012-08-07 | 2015-06-02 | Covidien Lp | Microwave ablation catheter and method of utilizing the same |
US8932283B2 (en) | 2012-09-27 | 2015-01-13 | Electromedical Associates, Llc | Cable assemblies for electrosurgical devices and methods of use |
US11937873B2 (en) | 2013-03-12 | 2024-03-26 | Boston Scientific Medical Device Limited | Electrosurgical device having a lumen |
EP3378429B1 (en) | 2013-03-29 | 2020-08-19 | Covidien LP | Method of manufacturing of coaxial microwave ablation applicators |
US10624697B2 (en) | 2014-08-26 | 2020-04-21 | Covidien Lp | Microwave ablation system |
US10813691B2 (en) | 2014-10-01 | 2020-10-27 | Covidien Lp | Miniaturized microwave ablation assembly |
JP6673598B2 (en) | 2014-11-19 | 2020-03-25 | エピックス セラピューティクス,インコーポレイテッド | High resolution mapping of tissue with pacing |
CA2967829A1 (en) | 2014-11-19 | 2016-05-26 | Advanced Cardiac Therapeutics, Inc. | Systems and methods for high-resolution mapping of tissue |
EP3220843B1 (en) | 2014-11-19 | 2020-01-01 | EPiX Therapeutics, Inc. | Ablation devices and methods of using a high-resolution electrode assembly |
US9636164B2 (en) | 2015-03-25 | 2017-05-02 | Advanced Cardiac Therapeutics, Inc. | Contact sensing systems and methods |
KR20180075603A (en) | 2015-10-26 | 2018-07-04 | 뉴웨이브 메디컬, 인코포레이티드 | Apparatus for securing medical devices and related methods |
CA3003192A1 (en) | 2015-10-26 | 2017-05-04 | Neuwave Medical, Inc. | A device for delivering microwave energy and uses thereof |
US10813692B2 (en) | 2016-02-29 | 2020-10-27 | Covidien Lp | 90-degree interlocking geometry for introducer for facilitating deployment of microwave radiating catheter |
SG11201807618QA (en) | 2016-03-15 | 2018-10-30 | Epix Therapeutics Inc | Improved devices, systems and methods for irrigated ablation |
MX2018012563A (en) | 2016-04-15 | 2019-07-08 | Neuwave Medical Inc | Systems for energy delivery. |
US10376309B2 (en) | 2016-08-02 | 2019-08-13 | Covidien Lp | Ablation cable assemblies and a method of manufacturing the same |
US11197715B2 (en) | 2016-08-02 | 2021-12-14 | Covidien Lp | Ablation cable assemblies and a method of manufacturing the same |
US11065053B2 (en) | 2016-08-02 | 2021-07-20 | Covidien Lp | Ablation cable assemblies and a method of manufacturing the same |
GB201614581D0 (en) | 2016-08-26 | 2016-10-12 | Emblation Ltd | Microwave instrument |
WO2018200865A1 (en) | 2017-04-27 | 2018-11-01 | Epix Therapeutics, Inc. | Determining nature of contact between catheter tip and tissue |
US20190246876A1 (en) | 2018-02-15 | 2019-08-15 | Neuwave Medical, Inc. | Compositions and methods for directing endoscopic devices |
US20190247117A1 (en) | 2018-02-15 | 2019-08-15 | Neuwave Medical, Inc. | Energy delivery devices and related systems and methods thereof |
US11672596B2 (en) | 2018-02-26 | 2023-06-13 | Neuwave Medical, Inc. | Energy delivery devices with flexible and adjustable tips |
EP3776723A4 (en) * | 2018-03-29 | 2021-12-15 | Intuitive Surgical Operations, Inc. | Systems and methods related to flexible antennas |
CA3120832A1 (en) | 2018-11-27 | 2020-06-04 | Neuwave Medical, Inc. | Endoscopic system for energy delivery |
JP2022513468A (en) | 2018-12-13 | 2022-02-08 | ニューウェーブ メディカル,インコーポレイテッド | Energy delivery devices and related systems |
US11832879B2 (en) | 2019-03-08 | 2023-12-05 | Neuwave Medical, Inc. | Systems and methods for energy delivery |
US11786303B2 (en) * | 2021-03-19 | 2023-10-17 | Quicker-Instrument Inc. | Microwave ablation probe |
US20230088132A1 (en) | 2021-09-22 | 2023-03-23 | NewWave Medical, Inc. | Systems and methods for real-time image-based device localization |
WO2023156965A1 (en) | 2022-02-18 | 2023-08-24 | Neuwave Medical, Inc. | Coupling devices and related systems |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4641649A (en) | 1985-10-30 | 1987-02-10 | Rca Corporation | Method and apparatus for high frequency catheter ablation |
US5230349A (en) * | 1988-11-25 | 1993-07-27 | Sensor Electronics, Inc. | Electrical heating catheter |
US5246438A (en) | 1988-11-25 | 1993-09-21 | Sensor Electronics, Inc. | Method of radiofrequency ablation |
US5314466A (en) | 1992-04-13 | 1994-05-24 | Ep Technologies, Inc. | Articulated unidirectional microwave antenna systems for cardiac ablation |
US5405346A (en) | 1993-05-14 | 1995-04-11 | Fidus Medical Technology Corporation | Tunable microwave ablation catheter |
Family Cites Families (172)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1586645A (en) | 1925-07-06 | 1926-06-01 | Bierman William | Method of and means for treating animal tissue to coagulate the same |
US3598108A (en) | 1969-02-28 | 1971-08-10 | Khosrow Jamshidi | Biopsy technique and biopsy device |
US3827436A (en) | 1972-11-10 | 1974-08-06 | Frigitronics Of Conn Inc | Multipurpose cryosurgical probe |
DE7305040U (en) | 1973-02-10 | 1973-06-20 | Lindemann H | ELECTROCOAGULATION FORCEPS FOR TUBE STERILIZATION USING BIPOLAR HIGH-FREQUENCY HEAT RADIATION |
US3886944A (en) | 1973-11-19 | 1975-06-03 | Khosrow Jamshidi | Microcautery device |
NL7502008A (en) | 1974-02-25 | 1975-08-27 | German Schmitt | INTRAKARDIAL STIMULATING ELECTRODE. |
DE2513868C2 (en) | 1974-04-01 | 1982-11-04 | Olympus Optical Co., Ltd., Tokyo | Bipolar electrodiathermy forceps |
US4033357A (en) | 1975-02-07 | 1977-07-05 | Medtronic, Inc. | Non-fibrosing cardiac electrode |
US4045056A (en) | 1975-10-14 | 1977-08-30 | Gennady Petrovich Kandakov | Expansion compensator for pipelines |
US4073287A (en) | 1976-04-05 | 1978-02-14 | American Medical Systems, Inc. | Urethral profilometry catheter |
DE2646229A1 (en) | 1976-10-13 | 1978-04-20 | Erbe Elektromedizin | HIGH FREQUENCY SURGICAL EQUIPMENT |
US4245624A (en) | 1977-01-20 | 1981-01-20 | Olympus Optical Co., Ltd. | Endoscope with flexible tip control |
FR2421628A1 (en) | 1977-04-08 | 1979-11-02 | Cgr Mev | LOCALIZED HEATING DEVICE USING VERY HIGH FREQUENCY ELECTROMAGNETIC WAVES, FOR MEDICAL APPLICATIONS |
US4204549A (en) | 1977-12-12 | 1980-05-27 | Rca Corporation | Coaxial applicator for microwave hyperthermia |
GB2022640B (en) | 1978-05-25 | 1982-08-11 | English Card Clothing | Interlocking card-clothing wire |
US4448198A (en) | 1979-06-19 | 1984-05-15 | Bsd Medical Corporation | Invasive hyperthermia apparatus and method |
US4476872A (en) | 1980-03-07 | 1984-10-16 | The Kendall Company | Esophageal probe with disposable cover |
US4462412A (en) | 1980-04-02 | 1984-07-31 | Bsd Medical Corporation | Annular electromagnetic radiation applicator for biological tissue, and method |
JPS5725863A (en) | 1980-07-23 | 1982-02-10 | Olympus Optical Co | Endoscope with microwave heater |
US4565200A (en) | 1980-09-24 | 1986-01-21 | Cosman Eric R | Universal lesion and recording electrode system |
US4416276A (en) | 1981-10-26 | 1983-11-22 | Valleylab, Inc. | Adaptive, return electrode monitoring system |
JPS58173541A (en) | 1982-04-03 | 1983-10-12 | 銭谷 利男 | Operation by microwave |
US4445892A (en) | 1982-05-06 | 1984-05-01 | Laserscope, Inc. | Dual balloon catheter device |
US4465079A (en) | 1982-10-13 | 1984-08-14 | Medtronic, Inc. | Biomedical lead with fibrosis-inducing anchoring strand |
US4583556A (en) | 1982-12-13 | 1986-04-22 | M/A-Com, Inc. | Microwave applicator/receiver apparatus |
DE3300694A1 (en) | 1983-01-11 | 1984-08-09 | Siemens AG, 1000 Berlin und 8000 München | BIPOLAR ELECTRODE FOR MEDICAL APPLICATIONS |
DE3306402C2 (en) | 1983-02-24 | 1985-03-07 | Werner Prof. Dr.-Ing. 6301 Wettenberg Irnich | Monitoring device for a high-frequency surgical device |
US4655219A (en) | 1983-07-22 | 1987-04-07 | American Hospital Supply Corporation | Multicomponent flexible grasping device |
US4601296A (en) | 1983-10-07 | 1986-07-22 | Yeda Research And Development Co., Ltd. | Hyperthermia apparatus |
US4522212A (en) | 1983-11-14 | 1985-06-11 | Mansfield Scientific, Inc. | Endocardial electrode |
US5143073A (en) | 1983-12-14 | 1992-09-01 | Edap International, S.A. | Wave apparatus system |
USRE33590E (en) | 1983-12-14 | 1991-05-21 | Edap International, S.A. | Method for examining, localizing and treating with ultrasound |
CH662669A5 (en) | 1984-04-09 | 1987-10-15 | Straumann Inst Ag | GUIDE DEVICE FOR AT LEAST PARTIAL INSERTION IN A HUMAN OR ANIMAL BODY, WITH A HELM AT LEAST MADE FROM A LADDER. |
US4573473A (en) | 1984-04-13 | 1986-03-04 | Cordis Corporation | Cardiac mapping probe |
US4800899A (en) | 1984-10-22 | 1989-01-31 | Microthermia Technology, Inc. | Apparatus for destroying cells in tumors and the like |
US4564200A (en) | 1984-12-14 | 1986-01-14 | Loring Wolson J | Tethered ring game with hook configuration |
US5192278A (en) | 1985-03-22 | 1993-03-09 | Massachusetts Institute Of Technology | Multi-fiber plug for a laser catheter |
DE3511107A1 (en) | 1985-03-27 | 1986-10-02 | Fischer MET GmbH, 7800 Freiburg | DEVICE FOR BIPOLAR HIGH-FREQUENCY COAGULATION OF BIOLOGICAL TISSUE |
US4641646A (en) | 1985-04-05 | 1987-02-10 | Kenneth E. Schultz | Endotracheal tube/respirator tubing connecting lock mechanism and method of using same |
US4891483A (en) | 1985-06-29 | 1990-01-02 | Tokyo Keiki Co. Ltd. | Heating apparatus for hyperthermia |
US4841990A (en) | 1985-06-29 | 1989-06-27 | Tokyo Keiki Co., Ltd. | Applicator for use in hyperthermia |
US4660571A (en) | 1985-07-18 | 1987-04-28 | Cordis Corporation | Percutaneous lead having radially adjustable electrode |
US4681122A (en) | 1985-09-23 | 1987-07-21 | Victory Engineering Corp. | Stereotaxic catheter for microwave thermotherapy |
US4699147A (en) | 1985-09-25 | 1987-10-13 | Cordis Corporation | Intraventricular multielectrode cardial mapping probe and method for using same |
US4785815A (en) | 1985-10-23 | 1988-11-22 | Cordis Corporation | Apparatus for locating and ablating cardiac conduction pathways |
US4763668A (en) | 1985-10-28 | 1988-08-16 | Mill Rose Laboratories | Partible forceps instrument for endoscopy |
US4643186A (en) * | 1985-10-30 | 1987-02-17 | Rca Corporation | Percutaneous transluminal microwave catheter angioplasty |
US4924864A (en) | 1985-11-15 | 1990-05-15 | Danzig Fred G | Apparatus and article for ligating blood vessels, nerves and other anatomical structures |
US4700716A (en) | 1986-02-27 | 1987-10-20 | Kasevich Associates, Inc. | Collinear antenna array applicator |
IL78755A0 (en) | 1986-05-12 | 1986-08-31 | Biodan Medical Systems Ltd | Applicator for insertion into a body opening for medical purposes |
JPH01502090A (en) | 1986-09-12 | 1989-07-27 | オーラル・ロバーツ・ユニバーシティ | Surgical tools using electromagnetic waves |
US4825880A (en) | 1987-06-19 | 1989-05-02 | The Regents Of The University Of California | Implantable helical coil microwave antenna |
US5097845A (en) | 1987-10-15 | 1992-03-24 | Labthermics Technologies | Microwave hyperthermia probe |
US4841988A (en) | 1987-10-15 | 1989-06-27 | Marquette Electronics, Inc. | Microwave hyperthermia probe |
FR2622098B1 (en) | 1987-10-27 | 1990-03-16 | Glace Christian | METHOD AND AZIMUTAL PROBE FOR LOCATING THE EMERGENCY POINT OF VENTRICULAR TACHYCARDIES |
US4832048A (en) | 1987-10-29 | 1989-05-23 | Cordis Corporation | Suction ablation catheter |
US4924863A (en) | 1988-05-04 | 1990-05-15 | Mmtc, Inc. | Angioplastic method for removing plaque from a vas |
AU3696989A (en) | 1988-05-18 | 1989-12-12 | Kasevich Associates, Inc. | Microwave balloon angioplasty |
US4938217A (en) | 1988-06-21 | 1990-07-03 | Massachusetts Institute Of Technology | Electronically-controlled variable focus ultrasound hyperthermia system |
US4881543A (en) | 1988-06-28 | 1989-11-21 | Massachusetts Institute Of Technology | Combined microwave heating and surface cooling of the cornea |
US4920978A (en) | 1988-08-31 | 1990-05-01 | Triangle Research And Development Corporation | Method and apparatus for the endoscopic treatment of deep tumors using RF hyperthermia |
US5147355A (en) | 1988-09-23 | 1992-09-15 | Brigham And Womens Hospital | Cryoablation catheter and method of performing cryoablation |
US4932420A (en) | 1988-10-07 | 1990-06-12 | Clini-Therm Corporation | Non-invasive quarter wavelength microwave applicator for hyperthermia treatment |
US4966597A (en) | 1988-11-04 | 1990-10-30 | Cosman Eric R | Thermometric cardiac tissue ablation electrode with ultra-sensitive temperature detection |
US5150717A (en) | 1988-11-10 | 1992-09-29 | Arye Rosen | Microwave aided balloon angioplasty with guide filament |
US5108390A (en) | 1988-11-14 | 1992-04-28 | Frigitronics, Inc. | Flexible cryoprobe |
US4960134A (en) | 1988-11-18 | 1990-10-02 | Webster Wilton W Jr | Steerable catheter |
GB2226497B (en) | 1988-12-01 | 1992-07-01 | Spembly Medical Ltd | Cryosurgical probe |
US4976711A (en) | 1989-04-13 | 1990-12-11 | Everest Medical Corporation | Ablation catheter with selectively deployable electrodes |
CA2053909A1 (en) | 1989-05-03 | 1990-11-04 | Robert A. Roth | Instrument and method for intraluminally relieving stenosis |
US5007437A (en) | 1989-06-16 | 1991-04-16 | Mmtc, Inc. | Catheters for treating prostate disease |
US5188122A (en) | 1989-06-20 | 1993-02-23 | Rocket Of London Limited | Electromagnetic energy generation method |
DE3926934A1 (en) * | 1989-08-16 | 1991-02-21 | Deutsches Krebsforsch | HYPERTHERMIC MICROWAVE APPLICATOR FOR WARMING A LIMITED ENVIRONMENT IN A DISSIPATIVE MEDIUM |
US5104393A (en) | 1989-08-30 | 1992-04-14 | Angelase, Inc. | Catheter |
US5114403A (en) | 1989-09-15 | 1992-05-19 | Eclipse Surgical Technologies, Inc. | Catheter torque mechanism |
US5100388A (en) | 1989-09-15 | 1992-03-31 | Interventional Thermodynamics, Inc. | Method and device for thermal ablation of hollow body organs |
US5044375A (en) | 1989-12-08 | 1991-09-03 | Cardiac Pacemakers, Inc. | Unitary intravascular defibrillating catheter with separate bipolar sensing |
EP0548122A1 (en) * | 1990-09-14 | 1993-06-30 | American Medical Systems, Inc. | Combined hyperthermia and dilation catheter |
US5172699A (en) | 1990-10-19 | 1992-12-22 | Angelase, Inc. | Process of identification of a ventricular tachycardia (VT) active site and an ablation catheter system |
US5171255A (en) | 1990-11-21 | 1992-12-15 | Everest Medical Corporation | Biopsy device |
US5085659A (en) | 1990-11-21 | 1992-02-04 | Everest Medical Corporation | Biopsy device with bipolar coagulation capability |
US5139496A (en) | 1990-12-20 | 1992-08-18 | Hed Aharon Z | Ultrasonic freeze ablation catheters and probes |
US5156151A (en) | 1991-02-15 | 1992-10-20 | Cardiac Pathways Corporation | Endocardial mapping and ablation system and catheter probe |
US5147357A (en) | 1991-03-18 | 1992-09-15 | Rose Anthony T | Medical instrument |
US5207674A (en) | 1991-05-13 | 1993-05-04 | Hamilton Archie C | Electronic cryogenic surgical probe apparatus and method |
WO1992021285A1 (en) * | 1991-05-24 | 1992-12-10 | Ep Technologies, Inc. | Combination monophasic action potential/ablation catheter and high-performance filter system |
US5301687A (en) * | 1991-06-06 | 1994-04-12 | Trustees Of Dartmouth College | Microwave applicator for transurethral hyperthermia |
US5861002A (en) * | 1991-10-18 | 1999-01-19 | Desai; Ashvin H. | Endoscopic surgical instrument |
US5230334A (en) | 1992-01-22 | 1993-07-27 | Summit Technology, Inc. | Method and apparatus for generating localized hyperthermia |
US5222501A (en) | 1992-01-31 | 1993-06-29 | Duke University | Methods for the diagnosis and ablation treatment of ventricular tachycardia |
US5295955A (en) * | 1992-02-14 | 1994-03-22 | Amt, Inc. | Method and apparatus for microwave aided liposuction |
US5242441A (en) | 1992-02-24 | 1993-09-07 | Boaz Avitall | Deflectable catheter with rotatable tip electrode |
US5263493A (en) | 1992-02-24 | 1993-11-23 | Boaz Avitall | Deflectable loop electrode array mapping and ablation catheter for cardiac chambers |
AU4026793A (en) * | 1992-04-10 | 1993-11-18 | Cardiorhythm | Shapable handle for steerable electrode catheter |
US5281217A (en) | 1992-04-13 | 1994-01-25 | Ep Technologies, Inc. | Steerable antenna systems for cardiac ablation that minimize tissue damage and blood coagulation due to conductive heating patterns |
WO1993020768A1 (en) * | 1992-04-13 | 1993-10-28 | Ep Technologies, Inc. | Steerable microwave antenna systems for cardiac ablation |
US5281215A (en) | 1992-04-16 | 1994-01-25 | Implemed, Inc. | Cryogenic catheter |
US5281213A (en) | 1992-04-16 | 1994-01-25 | Implemed, Inc. | Catheter for ice mapping and ablation |
US5295484A (en) * | 1992-05-19 | 1994-03-22 | Arizona Board Of Regents For And On Behalf Of The University Of Arizona | Apparatus and method for intra-cardiac ablation of arrhythmias |
US5248312A (en) | 1992-06-01 | 1993-09-28 | Sensor Electronics, Inc. | Liquid metal-filled balloon |
WO1994002077A2 (en) * | 1992-07-15 | 1994-02-03 | Angelase, Inc. | Ablation catheter system |
US5322507A (en) * | 1992-08-11 | 1994-06-21 | Myriadlase, Inc. | Endoscope for treatment of prostate |
US5720718A (en) * | 1992-08-12 | 1998-02-24 | Vidamed, Inc. | Medical probe apparatus with enhanced RF, resistance heating, and microwave ablation capabilities |
US5470308A (en) * | 1992-08-12 | 1995-11-28 | Vidamed, Inc. | Medical probe with biopsy stylet |
US5293869A (en) * | 1992-09-25 | 1994-03-15 | Ep Technologies, Inc. | Cardiac probe with dynamic support for maintaining constant surface contact during heart systole and diastole |
WO1994010924A1 (en) * | 1992-11-13 | 1994-05-26 | American Cardiac Ablation Co., Inc. | Fluid cooled electrosurgical probe |
US5391147A (en) * | 1992-12-01 | 1995-02-21 | Cardiac Pathways Corporation | Steerable catheter with adjustable bend location and/or radius and method |
IT1266217B1 (en) * | 1993-01-18 | 1996-12-27 | Xtrode Srl | ELECTROCATHETER FOR MAPPING AND INTERVENTION ON HEART CAVITIES. |
US6161543A (en) * | 1993-02-22 | 2000-12-19 | Epicor, Inc. | Methods of epicardial ablation for creating a lesion around the pulmonary veins |
US5797960A (en) * | 1993-02-22 | 1998-08-25 | Stevens; John H. | Method and apparatus for thoracoscopic intracardiac procedures |
US5383922A (en) * | 1993-03-15 | 1995-01-24 | Medtronic, Inc. | RF lead fixation and implantable lead |
US5494039A (en) * | 1993-07-16 | 1996-02-27 | Cryomedical Sciences, Inc. | Biopsy needle insertion guide and method of use in prostate cryosurgery |
US5487757A (en) * | 1993-07-20 | 1996-01-30 | Medtronic Cardiorhythm | Multicurve deflectable catheter |
US5496312A (en) * | 1993-10-07 | 1996-03-05 | Valleylab Inc. | Impedance and temperature generator control |
US5673695A (en) * | 1995-08-02 | 1997-10-07 | Ep Technologies, Inc. | Methods for locating and ablating accessory pathways in the heart |
US5582609A (en) * | 1993-10-14 | 1996-12-10 | Ep Technologies, Inc. | Systems and methods for forming large lesions in body tissue using curvilinear electrode elements |
US5599346A (en) * | 1993-11-08 | 1997-02-04 | Zomed International, Inc. | RF treatment system |
US5484433A (en) * | 1993-12-30 | 1996-01-16 | The Spectranetics Corporation | Tissue ablating device having a deflectable ablation area and method of using same |
US5873828A (en) * | 1994-02-18 | 1999-02-23 | Olympus Optical Co., Ltd. | Ultrasonic diagnosis and treatment system |
US5492126A (en) * | 1994-05-02 | 1996-02-20 | Focal Surgery | Probe for medical imaging and therapy using ultrasound |
US5593405A (en) * | 1994-07-16 | 1997-01-14 | Osypka; Peter | Fiber optic endoscope |
US6030382A (en) * | 1994-08-08 | 2000-02-29 | Ep Technologies, Inc. | Flexible tissue ablatin elements for making long lesions |
US5603697A (en) * | 1995-02-14 | 1997-02-18 | Fidus Medical Technology Corporation | Steering mechanism for catheters and methods for making same |
US5707369A (en) * | 1995-04-24 | 1998-01-13 | Ethicon Endo-Surgery, Inc. | Temperature feedback monitor for hemostatic surgical instrument |
US5606974A (en) * | 1995-05-02 | 1997-03-04 | Heart Rhythm Technologies, Inc. | Catheter having ultrasonic device |
US5683382A (en) * | 1995-05-15 | 1997-11-04 | Arrow International Investment Corp. | Microwave antenna catheter |
US5718241A (en) * | 1995-06-07 | 1998-02-17 | Biosense, Inc. | Apparatus and method for treating cardiac arrhythmias with no discrete target |
US5868737A (en) * | 1995-06-09 | 1999-02-09 | Engineering Research & Associates, Inc. | Apparatus and method for determining ablation |
ES2154824T5 (en) * | 1995-06-23 | 2005-04-01 | Gyrus Medical Limited | ELECTROCHIRURGICAL INSTRUMENT. |
US5863290A (en) * | 1995-08-15 | 1999-01-26 | Rita Medical Systems | Multiple antenna ablation apparatus and method |
US5590657A (en) * | 1995-11-06 | 1997-01-07 | The Regents Of The University Of Michigan | Phased array ultrasound system and method for cardiac ablation |
CA2242356C (en) * | 1996-01-08 | 2005-08-23 | Biosense, Inc. | Methods and apparatus for myocardial revascularization |
US6182664B1 (en) * | 1996-02-19 | 2001-02-06 | Edwards Lifesciences Corporation | Minimally invasive cardiac valve surgery procedure |
US6032077A (en) * | 1996-03-06 | 2000-02-29 | Cardiac Pathways Corporation | Ablation catheter with electrical coupling via foam drenched with a conductive fluid |
US6027497A (en) * | 1996-03-29 | 2000-02-22 | Eclipse Surgical Technologies, Inc. | TMR energy delivery system |
US6047216A (en) * | 1996-04-17 | 2000-04-04 | The United States Of America Represented By The Administrator Of The National Aeronautics And Space Administration | Endothelium preserving microwave treatment for atherosclerosis |
US5904709A (en) * | 1996-04-17 | 1999-05-18 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Microwave treatment for cardiac arrhythmias |
AUPN957296A0 (en) * | 1996-04-30 | 1996-05-23 | Cardiac Crc Nominees Pty Limited | A system for simultaneous unipolar multi-electrode ablation |
NL1003024C2 (en) * | 1996-05-03 | 1997-11-06 | Tjong Hauw Sie | Stimulus conduction blocking instrument. |
US5861021A (en) * | 1996-06-17 | 1999-01-19 | Urologix Inc | Microwave thermal therapy of cardiac tissue |
US6016848A (en) * | 1996-07-16 | 2000-01-25 | W. L. Gore & Associates, Inc. | Fluoropolymer tubes and methods of making same |
US5720775A (en) * | 1996-07-31 | 1998-02-24 | Cordis Corporation | Percutaneous atrial line ablation catheter |
US6126682A (en) * | 1996-08-13 | 2000-10-03 | Oratec Interventions, Inc. | Method for treating annular fissures in intervertebral discs |
US5810803A (en) * | 1996-10-16 | 1998-09-22 | Fidus Medical Technology Corporation | Conformal positioning assembly for microwave ablation catheter |
US6719755B2 (en) * | 1996-10-22 | 2004-04-13 | Epicor Medical, Inc. | Methods and devices for ablation |
US6311692B1 (en) * | 1996-10-22 | 2001-11-06 | Epicor, Inc. | Apparatus and method for diagnosis and therapy of electrophysiological disease |
US5871481A (en) * | 1997-04-11 | 1999-02-16 | Vidamed, Inc. | Tissue ablation apparatus and method |
US6012457A (en) * | 1997-07-08 | 2000-01-11 | The Regents Of The University Of California | Device and method for forming a circumferential conduction block in a pulmonary vein |
US6024740A (en) * | 1997-07-08 | 2000-02-15 | The Regents Of The University Of California | Circumferential ablation device assembly |
US5873896A (en) * | 1997-05-27 | 1999-02-23 | Uab Research Foundation | Cardiac device for reducing arrhythmia |
US6514249B1 (en) * | 1997-07-08 | 2003-02-04 | Atrionix, Inc. | Positioning system and method for orienting an ablation element within a pulmonary vein ostium |
US6051018A (en) * | 1997-07-31 | 2000-04-18 | Sandia Corporation | Hyperthermia apparatus |
US6010516A (en) * | 1998-03-20 | 2000-01-04 | Hulka; Jaroslav F. | Bipolar coaptation clamps |
DE69924750T2 (en) * | 1998-11-16 | 2006-03-02 | United States Surgical Corp., Norwalk | DEVICE FOR THE THERMAL TREATMENT OF TISSUE |
US6178354B1 (en) * | 1998-12-02 | 2001-01-23 | C. R. Bard, Inc. | Internal mechanism for displacing a slidable electrode |
US6190382B1 (en) * | 1998-12-14 | 2001-02-20 | Medwaves, Inc. | Radio-frequency based catheter system for ablation of body tissues |
US6097985A (en) * | 1999-02-09 | 2000-08-01 | Kai Technologies, Inc. | Microwave systems for medical hyperthermia, thermotherapy and diagnosis |
US6174309B1 (en) * | 1999-02-11 | 2001-01-16 | Medical Scientific, Inc. | Seal & cut electrosurgical instrument |
US6508774B1 (en) * | 1999-03-09 | 2003-01-21 | Transurgical, Inc. | Hifu applications with feedback control |
US6179776B1 (en) * | 1999-03-12 | 2001-01-30 | Scimed Life Systems, Inc. | Controllable endoscopic sheath apparatus and related method of use |
US6277113B1 (en) | 1999-05-28 | 2001-08-21 | Afx, Inc. | Monopole tip for ablation catheter and methods for using same |
US6696844B2 (en) * | 1999-06-04 | 2004-02-24 | Engineering & Research Associates, Inc. | Apparatus and method for real time determination of materials' electrical properties |
US6689062B1 (en) * | 1999-11-23 | 2004-02-10 | Microaccess Medical Systems, Inc. | Method and apparatus for transesophageal cardiovascular procedures |
EP1261258A1 (en) * | 2000-03-10 | 2002-12-04 | The Pillsbury Company | Scoopable dough and products resulting therefrom |
US6692491B1 (en) * | 2000-03-24 | 2004-02-17 | Scimed Life Systems, Inc. | Surgical methods and apparatus for positioning a diagnostic or therapeutic element around one or more pulmonary veins or other body structures |
US6673068B1 (en) * | 2000-04-12 | 2004-01-06 | Afx, Inc. | Electrode arrangement for use in a medical instrument |
US6546935B2 (en) * | 2000-04-27 | 2003-04-15 | Atricure, Inc. | Method for transmural ablation |
US20020107514A1 (en) * | 2000-04-27 | 2002-08-08 | Hooven Michael D. | Transmural ablation device with parallel jaws |
US6948287B2 (en) * | 2000-06-09 | 2005-09-27 | Doris Korn | Gap seal on a building structure |
US6511478B1 (en) * | 2000-06-30 | 2003-01-28 | Scimed Life Systems, Inc. | Medical probe with reduced number of temperature sensor wires |
US6685715B2 (en) * | 2001-05-02 | 2004-02-03 | Novare Surgical Systems | Clamp having bendable shaft |
US6878147B2 (en) * | 2001-11-02 | 2005-04-12 | Vivant Medical, Inc. | High-strength microwave antenna assemblies |
-
1999
- 1999-05-28 US US09/321,666 patent/US6277113B1/en not_active Expired - Fee Related
-
2000
- 2000-05-30 EP EP00932818A patent/EP1189542A1/en not_active Withdrawn
- 2000-05-30 WO PCT/US2000/014953 patent/WO2001001876A1/en active Application Filing
-
2001
- 2001-07-31 US US09/904,156 patent/US6823218B2/en not_active Expired - Fee Related
-
2004
- 2004-11-12 US US10/988,028 patent/US7346399B2/en not_active Expired - Fee Related
-
2008
- 2008-02-12 US US12/029,693 patent/US20080132883A1/en not_active Abandoned
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4641649A (en) | 1985-10-30 | 1987-02-10 | Rca Corporation | Method and apparatus for high frequency catheter ablation |
US5230349A (en) * | 1988-11-25 | 1993-07-27 | Sensor Electronics, Inc. | Electrical heating catheter |
US5246438A (en) | 1988-11-25 | 1993-09-21 | Sensor Electronics, Inc. | Method of radiofrequency ablation |
US5314466A (en) | 1992-04-13 | 1994-05-24 | Ep Technologies, Inc. | Articulated unidirectional microwave antenna systems for cardiac ablation |
US5405346A (en) | 1993-05-14 | 1995-04-11 | Fidus Medical Technology Corporation | Tunable microwave ablation catheter |
Also Published As
Publication number | Publication date |
---|---|
US20020111613A1 (en) | 2002-08-15 |
US6277113B1 (en) | 2001-08-21 |
EP1189542A1 (en) | 2002-03-27 |
US6823218B2 (en) | 2004-11-23 |
US20080132883A1 (en) | 2008-06-05 |
US20060206107A1 (en) | 2006-09-14 |
US7346399B2 (en) | 2008-03-18 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7346399B2 (en) | Monopole tip for ablation catheter | |
US20180235694A1 (en) | Microwave ablation devices including expandable antennas and methods of use | |
EP1669036B1 (en) | Surgical microwave ablation assembly | |
US5800494A (en) | Microwave ablation catheters having antennas with distal fire capabilities | |
EP2226030B1 (en) | High-strenght microwave antenna assemblies | |
US5810803A (en) | Conformal positioning assembly for microwave ablation catheter | |
US6016811A (en) | Method of using a microwave ablation catheter with a loop configuration | |
US5741249A (en) | Anchoring tip assembly for microwave ablation catheter | |
US7998139B2 (en) | Cooled helical antenna for microwave ablation | |
US6673068B1 (en) | Electrode arrangement for use in a medical instrument | |
US9333032B2 (en) | Microwave antenna assembly and method of using the same | |
AU2011200329B2 (en) | System and method for performing an electrosurgical procedure using an ablation device with an integrated imaging device | |
US6379349B1 (en) | Arrangement for electrothermal treatment of the human or animal body | |
EP0745354A2 (en) | Radiofrequency ablation catheter | |
US20010029368A1 (en) | End-firing microwave ablation instrument with horn reflection device | |
JP2002532132A (en) | High frequency based catheter device and hollow coaxial cable for cutting body tissue | |
EP1145686B1 (en) | Ablation catheter with a directional hf irradiator | |
Rappaport | Treating cardiac disease with catheter-based tissue heating | |
Rappaport | Cardiac tissue ablation with catheter-based microwave heating | |
WO2024012822A1 (en) | Electrosurgical instrument for conveying and emitting microwave electromagnetic energy into biological tissue for tissue treatment |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
WWE | Wipo information: entry into national phase |
Ref document number: 2000932818 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 2000932818 Country of ref document: EP |