US 20070282333 A1
An ultrasonic clamp coagulator assembly that is configured to permit selective cutting, coagulation and clamping of tissue during surgical procedures. An elongated portion of the instrument can be configured for endoscopic applications and has an outside diameter of less than 6 mm. The construction includes a waveguide and blade that enable larger wave amplitude and a longer active blade length and still provide sufficient frequency margin or window. The waveguide is provided with a series of gain steps located at the distal portion of the waveguide preferably at the two most distal nodes in relation to the handpiece, or the two most proximal nodes in relation to the blade tip.
1. An ultrasonic surgical waveguide having a proximal portion and a distal portion and the distal portion comprising an ultrasonic surgical blade body, the blade body having a distal tip, which is the most-distal vibration antinode; wherein the distal portion comprises a first gain step greater than unity and a second gain step greater than unity.
2. The surgical waveguide of
3. The surgical waveguide of
4. The surgical waveguide of
5. The surgical waveguide of
6. The surgical waveguide of
7. The surgical waveguide of
8. The surgical waveguide of
9. The surgical waveguide of
10. The surgical waveguide of
11. An ultrasonic surgical waveguide having a proximal portion and a distal portion and the distal portion comprising an ultrasonic surgical blade body, the blade body having a distal tip, which is the most-distal vibration antinode; wherein the distal portion, proximal to the blade body, comprises a first gain step greater than unity and a second gain step greater than unity.
12. The surgical waveguide of
13. An ultrasonic surgical waveguide having a proximal portion and a distal portion and the distal portion comprising an ultrasonic surgical blade body, the blade body having a distal tip, which is the most-distal vibration antinode; wherein the distal portion comprises a first gain step greater than unity and a second gain step less than unity.
14. The surgical waveguide of
15. The surgical waveguide of
16. The surgical waveguide of
17. The surgical waveguide of
18. The surgical waveguide of
19. An ultrasonic surgical waveguide having a proximal portion and a distal portion and the distal portion comprising an ultrasonic surgical blade body, the blade body having a distal tip, which is the most-distal vibration antinode; wherein the distal portion, proximal to the blade body, comprises a first gain step greater than unity and a second gain step less than unity.
The present application claims the priority benefit of U.S. provisional patent application Ser. No. 60/809,971, filed on Jun. 1, 2006.
The present invention relates, in general, to ultrasonic surgical instruments and, more particularly, to an ultrasonic surgical clamp coagulator apparatus particularly configured to provide increased tissue transection forces.
This application contains subject matter that relates to and incorporates by reference in their entirety, for any and all purposes, the following non-provisional applications:
ULTRASONIC SURGICAL BLADE AND INSTRUMENT HAVING A GAIN STEP, U.S. Pat. No. 7,163,548.
TISSUE PAD FOR USE WITH AN ULTRASONIC SURGICAL INSTRUMENT, Ser. No. 11/245,819, filed Oct. 7, 2005;
COMBINATION TISSUE PAD FOR USE WITH AN ULTRASONIC SURGICAL INSTRUMENT, Ser. No. 11/246,794, filed Oct. 7, 2005;
ACTUATION MECHANISM FOR USE WITH AN ULTRASONIC SURGICAL INSTRUMENT, Ser. No. 11/246,826, filed Oct. 7, 2005;
CLAMP MECHANISM FOR USE WITH AN ULTRASONIC SURGICAL INSTRUMENT, Ser. No. 11/246,264, filed Oct. 7, 2005;
FEEDBACK MECHANISM FOR USE WITH AN ULTRASONIC SURGICAL INSTRUMENT, Ser. No. 11/246,384, filed Oct. 7, 2005;
HANDLE ASSEMBLY HAVING HAND ACTIVATION FOR USE WITH AN ULTRASONIC SURGICAL INSTRUMENT, Ser. No. 11/246,330, filed Oct. 7, 2005;
ULTRASONIC SURGICAL SHEARS AND TISSUE PAD FOR SAME, Ser. No. 11/065,378, filed Feb. 24, 2005; and
HAND ACTIVATED ULTRASONIC INSTRUMENT, Ser. No. 10/869,351, filed Jun. 16, 2004.
Further, this application shares a common specification with the following U.S. patent applications filed contemporaneously herewith: TISSUE PAD FOR ULTRASONIC SURGICAL INSTRUMENT, Ser. No. [Atty docket no. END5881 USNP]; ULTRASONIC BLADE SUPPORT, Ser. No. [Atty docket no. END5881 USNP2]; and MECHANISM FOR ASSEMBLY OF ULTRASONIC INSTRUMENT, Ser. No. [Atty docket no. END5881 USNP3].
Ultrasonic surgical instruments are finding increasingly widespread applications in surgical procedures by virtue of the unique performance characteristics of such instruments. Depending upon specific instrument configurations and operational parameters, ultrasonic surgical instruments can provide substantially simultaneous cutting of tissue and hemostasis by coagulation, desirably minimizing patient trauma. The cutting action is typically effected by an end-effector or blade tip at the distal end of the instrument, which transmits ultrasonic energy to tissue brought into contact with the end-effector. Ultrasonic instruments of this nature can be configured for open surgical use, laparoscopic or endoscopic surgical procedures including robotic-assisted procedures.
Ultrasonic surgical instruments have been developed that include a clamp mechanism to press tissue against the blade of the end-effector in order to couple ultrasonic energy to the tissue of a patient. Such an arrangement (sometimes referred to as a clamp coagulator shears or an ultrasonic transactor) is disclosed in U.S. Pat. Nos. 5,322,055; 5,873,873 and 6,325,811, all of which are incorporated herein by reference. The surgeon activates the clamp arm to press the clamp pad against the blade by squeezing on the handgrip or handle.
Some current ultrasonic shears devices, however, have the tendency to create tissue tags. Tissue tags are the tissue that remains clamped in the jaw that is not transected after the majority of the tissue in the jaw has been transected and falls away. Tissue tags may result from insufficient end-effector or blade tip proximal loading and/or lower proximal blade activity. Surgeons may mitigate tissue tags either through the addition of vertical tension (i.e. putting tension on the tissue using the blade) or rearward traction on the device in order to move the untransected tissue to a more active portion of the blade to complete the cut.
Some current ultrasonic shears devices utilize tissue pads that close in parallel with the surface of the blade. This presents certain problems in terms of the pressure profile exerted on the tissue. As tissue is compressed between the jaw and the blade, the distal portion of the blade deflects under load more than the proximal portion of the blade. This deflection is created in part by the portion of the blade distal to the most distal node of the device. It is also partly created by the deflection of the waveguide or transmission rod proximal to the most distal node. Additionally, the fact that blade amplitude decreases moving proximal of the tip of the blade makes the situation worse since the amount of energy transferred to the tissue, even if the pressure was constant, is reduced.
Current tissue pad designs utilize PTFE material to contact the tissue and blade. Although these designs have been adequate, they tend to suffer from longevity issues since the pads tend to deteriorate over long surgical procedures. Additionally, newer designs of clamp coagulator shears increase blade amplitude and/or the loading of the pad against the tissue and blade and overwhelm the pad material, resulting in less than required tissue pad life. The pad material limits the amount of force that may be applied against the tissue and blade, which in turn limits the tissue thickness or vessel size that some current clamp coagulator shears may effectively cut and coagulate. Current composite pads may be difficult or expensive to manufacture.
Some current designs of clamp coagulator ultrasonic shears are limited in the length of the active blade available for use by surgeons due to inherent limitations in the effective transfer of mechanical motion along the longitudinal path of the blade from the transducer assembly. Although new blade geometry has mitigated some of these problems, longer active blade lengths, or blades that have more mass (created by larger diameter or larger lengths) have a tendency to shrink the frequency window between resonant and anti-resonant frequencies making it difficult or impossible for ultrasonic generators to lock on to the proper frequency to drive the waveguide, blade and transducer assembly.
Some current designs of clamp coagulator shears utilize elastomer material such as silicone for node supports along the length of the blade. The most distal node support is typically silicone to provide for a seal around the blade. Where higher clamp forces are desired, as is the case with longer active blade lengths, it is desirable to have a rigid distal node support. Many problems, however, are inherent with rigid node supports. Materials such as thermoset polymers that are capable of withstanding the pressure and temperature requirements of an ultrasonic blade node support are often too expensive to be utilized in production. The use of thermoplastics would improve manufacturability from a cost perspective but may not hold up to the pressure and temperature requirements of an ultrasonic blade node support.
Some current designs of clamp coagulator shears utilize a constant force spring mechanism that prevents the application of too much force to the clamp arm and blade. Although the mechanism provides relatively constant force to the system, the spring imparts some slope to the force curve. In applications where the clamp force is low, the slope is not significant. In applications with high clamp forces, however, the difference in force attributable to the slope over the possible range of spring compressions becomes very significant and may exceed the maximum force allowable in the blade, in the tube assemblies or in other components of the system. The high slope could allow the maximum force to be exceeded under abuse modes or through normal manufacturing tolerance variations. If this occurs, the blade may bend, the actuation mechanism may fail or undesirable tissue effects may occur (i.e. fast cutting, but minimal tissue coagulation). This situation is aggravated by the fact that a portion of the jaw (the clamp arm and pad) of the device can meet sufficient resistance to engage the force limiting mechanism when the clamp pad almost contacts the blade (when transecting thin tissue or at the end of the transection or clamping solid objects such as other devices) or when the clamp arm is still open with respect to the blade (when transecting thick tissue).
Some current designs of clamp coagulator shears utilize force-limiting springs to ensure that clamp forces are within a specified range. It is also necessary for the force-limiting spring design to allow the surgeon to “feather” (apply less than the maximum force and slowly increase to the maximum force). In these mechanisms, therefore, the jaw closes until a predetermined force is met and then the additional stroke drives the mechanism into the force limiting range. In some cases, though, the surgeon may, unknowingly, fail to apply the full force of the jaw against the tissue resulting in incomplete tissue cuts or insufficient coagulation. Alternatively, the surgeon may unknowingly open the clamp arm during a transection that results in incomplete tissue cuts or insufficient coagulation.
Some current designs of clamp coagulator shears utilize a foot pedal to energize the surgical instrument. The surgeon operates the foot pedal while simultaneously applying pressure to the handle to press tissue between the jaw and blade to activate a generator that provides energy that is transmitted to the cutting blade for cutting and coagulating tissue. Key drawbacks with this type of instrument activation include the loss of surgeon focus on the surgical field while the surgeon searches for the foot pedal, the foot pedal gets in the way of the surgeon's movement during a procedure and surgeon leg fatigue during long cases.
Some current designs of torque wrenches for ultrasonic surgical instruments utilize a multi-piece torque wrench for use in properly torqueing an instrument to an ultrasonic handpiece. A multi-piece assembly is more costly in that separate pieces have to be molded and then assembled. In addition, the pieces have a tendency to wear rapidly leading to failure of the wrench.
It would be desirable to provide an ultrasonic surgical instrument that overcomes some of the deficiencies of current instruments. The ultrasonic surgical instrument described herein overcomes those deficiencies.
The present invention meets the above stated needs for an waveguide and blade that enable larger wave amplitude and a longer active blade length and still provide sufficient frequency margin or window. The waveguide is provided with a series of gain steps located at the distal portion of the waveguide preferably at the two most distal nodes in relation to the handpiece, or the two most proximal nodes in relation to the blade tip.
The novel features of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to organization and methods of operation, may best be understood by reference to the following description, taken in conjunction with the accompanying drawings in which:
Before explaining the present invention in detail, it should be noted that the invention is not limited in its application or use to the details of construction and arrangement of parts illustrated in the accompanying drawings and description. The illustrative embodiments of the invention may be implemented or incorporated in other embodiments, variations and modifications, and may be practiced or carried out in various ways. Further, unless otherwise indicated, the terms and expressions employed herein have been chosen for the purpose of describing the illustrative embodiments of the present invention for the convenience of the reader and are not for the purpose of limiting the invention.
Further, it is understood that any one or more of the following-described embodiments, expressions of embodiments, examples, etc. can be combined with any one or more of the other following-described embodiments, expressions of embodiments, examples, etc.
The present invention is particularly directed to an improved ultrasonic surgical clamp coagulator apparatus which is configured for effecting tissue cutting, coagulation, and/or clamping during surgical procedures. The present apparatus can be readily configured for use in open surgical procedures, as well as laparoscopic or endoscopic procedures and robot-assisted surgical procedures. Versatile use is facilitated by selective use of ultrasonic energy. When ultrasonic components of the apparatus are inactive, tissue can be readily gripped and manipulated, as desired, without tissue cutting or damage. When the ultrasonic components are activated, the apparatus permits tissue to be gripped for coupling with the ultrasonic energy to effect tissue coagulation, with application of increased pressure efficiently effecting tissue cutting and coagulation. If desired, ultrasonic energy can be applied to tissue without use of the clamping mechanism of the apparatus by appropriate manipulation of the ultrasonic blade.
As will become apparent from the following description, the present clamp coagulator apparatus is particularly configured for disposable use by virtue of its straightforward construction. As such, it is contemplated that the apparatus be used in association with an ultrasonic generator unit and transducer of a surgical system, whereby ultrasonic energy from the generator unit provides the desired ultrasonic actuation through the transducer for the present clamp coagulator apparatus. It will be appreciated that a clamp coagulator apparatus embodying the principles of the present invention can be configured for non-disposable or multiple uses, and non-detachably integrated with an associated hand piece (or transducer) unit. However, detachable connection of the present clamp coagulator apparatus with an associated ultrasonic hand piece is presently preferred for single-patient use of the apparatus.
The present invention will be described in combination with an ultrasonic instrument as described herein. Such description is exemplary only, and is not intended to limit the scope and applications of the invention. For example, the invention is useful in combination with a multitude of ultrasonic instruments including those described in, for example, U.S. Pat. Nos. 5,938,633; 5,935,144; 5,944,737; 5,322,055, 5,630,420; and 5,449,370.
With reference to
The ultrasonic surgical instrument 100 includes a multi-piece handle 70 adapted to isolate the operator from the vibrations of the acoustic assembly contained within transducer 50. The handle 70 can be shaped to be held by a user in a conventional manner, but it is contemplated that the present ultrasonic surgical instrument 100 principally be grasped and manipulated by a scissor-like arrangement provided by a handle assembly of the instrument, as will be described. While single-piece handle 70 is illustrated, the handle 70 may comprise a single or unitary component. The proximal end of the ultrasonic surgical instrument 100 receives and is fitted to the distal end of the ultrasonic transducer 50 by insertion of the transducer into the handle 70. The ultrasonic surgical instrument 100 may be attached to and removed from the ultrasonic transducer 50 as a unit.
Referring specifically now to
The transmission assembly 71 may include an outer tubular member or outer sheath 72, an inner tubular actuating member 76, a waveguide 80 and end-effector 81 (blade 79, clamp arm 56, pin 56 b and one or more clamp pads 58). As will be described, the outer sheath 72, the actuating member 76, and the waveguide or transmission rod 80 may be joined together for rotation as a unit (together with ultrasonic transducer 50) relative to handle 70. The waveguide 80, which is adapted to transmit ultrasonic energy from transducer 50 to blade 79 may be flexible, semi-flexible or rigid.
The ultrasonic waveguide 80 may further include at least one radial hole or aperture 66 extending there through, substantially perpendicular to the longitudinal axis of the waveguide 80. The aperture 66, which may be positioned at a node, is configured to receive an insulated connector pin 27, which connects the waveguide 80, to the tubular actuating member 76, and the tubular outer sheath 72, as well the outer tube retainer 29. A rotation knob 28 (not shown) may be added to or may replace retainer 29 to facilitate rotation of the blade assembly 80, including the end effector 81 relative to instrument handle 70, as is known and understood in the art.
The blade 79 may be integral with the waveguide 80 and formed as a single unit. In an alternate expression of the current embodiment, a threaded connection, a welded joint, or other coupling mechanisms may connect blade 79 to waveguide 80. The distal end of the blade 79 is disposed near an anti-node in order to tune the acoustic assembly to a preferred resonant frequency fo when the acoustic assembly is not loaded by tissue. When ultrasonic transducer 50 is energized, the distal end of blade 79 is configured to move longitudinally in the range of, for example, approximately 10 to 500 microns peak-to-peak, and preferably in the range of about 20 to about 200 microns at a predetermined vibrational frequency fo of, for example, 55,500 Hz.
Referring now to
In one embodiment of the present invention, the waveguide 80 includes a hollow bore 101 located between the most distal vibration node and the distal tip of the blade 79 a. This hollow bore 101 in the instant embodiment, facilitates longer active blade length by stretching or expanding wavelength as is known and understood in the art. This longer active blade length may require larger diameter blades 79 to facilitate the bore. To ensure proper performance of the blade 79 and to achieve desired cutting and coagulation action of the blade, a larger wave amplitude may be used. Increasing active blade length and wave amplitude may create difficulties for the system to achieve resonance. For instance, a system tuned to resonate at 55,500 Hz, with the hollow bore blade, may achieve anti-resonance at 55,550 Hz. This narrow frequency window may make it difficult or impossible for the generator 30 (see
To enable larger wave amplitude and longer active blade lengths and still provide sufficient frequency margin or window, a waveguide 80 is provided with a series of gain steps in the waveguide 80. The gain of a gain step less than unity results from an increase in mass of the ultrasonic waveguide at a node, and the gain of a gain step greater than unity results from a decrease in mass of the waveguide at a node. A gain feature is any one of geometric constructions of the waveguide or blade that either increases or decreases the mass of the waveguide or blade at a node and include: a discrete change in outer diameter or perimeter, a taper, a longitudinal hole, a transverse hole, a void, a surface flat, a surface slot, and a change in material. The term hole includes a through hole and a non-through hole. Other gain features are left to the artisan.
In one embodiment of the present invention, a gain step 102, located at the second most distal vibration node (see
As is known and understood in the art, in an ultrasonic blade system, a generator produces a current to drive a transducer located within handpiece 50. This transducer imparts mechanical energy at a specific frequency to a waveguide and to a blade attached thereto. The generator continues to impart electrical energy to convert to mechanical energy as it varies the frequency in an effort to find and drive the system at its resonant frequency. Equating the transducer and waveguide as an equivalent electrical model, as the frequency of cycling is increased, starting at a non-resonant condition below the desired resonant frequency, the system's oscillations first approach a frequency at which impedance is minimum (maximum admittance). This minimum impedance frequency approximates the series resonance frequency, the frequency at which impedance in an electrical circuit describing the element is zero (assuming resistance caused by mechanical losses is ignored). The minimum impedance frequency also is the resonant frequency of the waveguide and blade assembly, which by design is nominally the same resonant frequency of the transducer. The composition of the transducer material and the shape and volume of the waveguide and blade assembly determine the resonance frequency. As the cycling frequency is further increased, impedance increases to a maximum (minimum admittance). The maximum impedance frequency, approximates the parallel resonance frequency, the frequency at which parallel resistance in the equivalent electrical circuit is infinite (assuming resistance caused by mechanical losses is ignored). The maximum impedance frequency also is the anti-resonance frequency. The larger the difference between resonant and anti-resonant frequencies (that is, the frequency window or phase margin), the easier it is for a generator to establish and maintain resonance in the waveguide and blade assembly as frequency tolerances are relaxed.
In the present invention, the gain step described above may cause a significant acoustic impedance mismatch, causing some of the mechanical energy transmitted along the waveguide to be reflected. As is seen in
Applicants have determined that locating the gain steps in the distal portion of the waveguide results in a greater phase margin or wider trough between resonant and anti-resonant frequencies. What is meant as the “distal portion” is the distal half of the waveguide. By delaying waveguide narrowing to the distal end of the waveguide, more mechanical energy is stored along the waveguide and any negative effects due to reflection at the gain steps are mitigated. It is appreciated that the gain step or combination step up/down/up may be located anywhere along the waveguide. For ideal system performance, however, the gain step(s) should be located in the distal half of the blade, preferably at the two most distal nodes in relation to the handpiece, or the two most proximal nodes in relation to the blade tip. Surprisingly, the Applicants found that the phase margin increased by almost 100% by relocating the gain steps to the distal portion of the waveguide. In early experiments of a waveguide having two gain steps, one at the proximal end and one at the distal end, the phase margin measured 30 to 40 Hz. In experiments of a waveguide having two gain steps, both located at the distal portion, the phase margin measured between 50 and 80 Hz. In experiments of a waveguide having two gain steps, one at each of the two most distal nodes, the phase margin measured between 75 and 80 Hz.
In another embodiment (not shown), a single gain step is located at either the first or second most distal node in relation to the tip of the blade 79 a. A single gain step may obviate the need for a step up and step down on the blade. To accommodate the hollow tip blade, the waveguide 80 must be of sufficient cross section to transmit a wave from the handpiece to the first gain step 102 and the difference in diameters between the waveguide and the blade must be sufficient to result in the wave amplitude gain from a step down, step up and step down combination. The diameter difference must be large enough to achieve correct blade longitudinal excursion while providing a sufficient frequency window for the system to lock on to resonance.
Referring again to
Referring now to
Referring back to
Ultrasonic transducer 50, and an ultrasonic waveguide 80 together provide an acoustic assembly of the present surgical system 19, with the acoustic assembly providing ultrasonic energy for surgical procedures when powered by generator 30. The acoustic assembly of surgical instrument 100 generally includes a first acoustic portion and a second acoustic portion. In the present embodiment, the first acoustic portion comprises the ultrasonically active portions of ultrasonic transducer 50, and the second acoustic portion comprises the ultrasonically active portions of transmission assembly 71. Further, in the present embodiment, the distal end of the first acoustic portion is operatively coupled to the proximal end of the second acoustic portion by, for example, a threaded connection.
With particular reference to
The force limiting mechanism 95 provides a portion of the clamp drive mechanism of the instrument 100, which affects pivotal movement of the clamp member 60 by reciprocation of actuating member 76. The clamp drive mechanism further includes a drive yoke 33 which is operatively connected with an operating trigger handle 34 of the instrument, with the operating trigger handle 34 thus interconnected with the reciprocable actuating member 76 via drive yoke 33 and force limiting mechanism 91. Trigger handle 34 is connected to drive yoke 33 and link 37 via pins 35 and 36. Spring 12 is located between drive yoke 33 and handle assembly 68 and 69 biasing reciprocable actuating member 76 to the open position.
Movement of trigger handle 34 toward handgrip 70 translates actuating member 76 proximally, thereby pivoting clamp member 60 toward blade 79. The scissor-like action provided by trigger handle 34 and cooperating handgrip 70 facilitates convenient and efficient manipulation and positioning of the instrument, and operation of the clamping mechanism at the distal portion of the instrument whereby tissue is efficiently urged against the blade 79. Movement of trigger handle 34 away from handgrip 68 translates actuating member 76 distally, thereby pivoting clamp member 60 away from blade 79.
With particular reference to
Tissue pads having composite construction, while having benefits and advantages over TEFLON pads, have cost and manufacturing disadvantages. Composite tissue pads are typically compression molded into a flat coupon. Such compression molding can be time consuming and expensive. Once the flat coupon is produced, it must be machined to produce a tissue pad suitable for use with a clamping ultrasonic device adding further time and expense to the manufacturing process.
With particular reference to
In an alternate expression of the current embodiment, clamp pad 58 includes a proximal portion 58 b that is smoother than distal portion 58 a (not shown) where distal portion 58 a includes a saw tooth like configuration. Proximal portion 58 b may be devoid of saw-tooth-like teeth or other tissue engaging surfaces contemplated. Utilizing a smooth proximal portion 58 b on clamp pad 58 allows tissue in the proximal region to move distally, following the vibratory motion of the blade, to the more active region of the blade 79 to prevent tissue tagging. This concept takes advantage of the inherent motion profile of blade 79. Due to sinusoidal motion, the greatest displacement or amplitude of motion is located at the most distal portion of blade 79, while the proximal portion of the tissue treatment region is on the order of 50% of the distal tip amplitude. During operation, the tissue in the proximal region of end effector (area of portion 58 b) will desiccate and thin, and the distal portion of end effector 81 will transect tissue in that distal region, thereby allowing the desiccated and thin tissue within the proximal region to slide distally into the more active region of end effector 81 to complete the tissue transaction.
In another expression of the current embodiment of the present invention, clamp pad 58 a is formed from TEFLON® or any other suitable low-friction material. Pad insert 58 d is formed from a composite material, such as a polyimide.
In one expression of one embodiment of the invention, a pad insert 58 d is formed from a cylinder of composite material. Referring to
Several benefits and advantages obtain from one or more of the expressions of the invention. Having a tissue pad with a base material and at-least-one pad insert material allows the base material and the at-least-one pad insert material to be chosen with a different hardness, stiffness, lubricity, dynamic coefficient of friction, heat transfer coefficient, abradability, heat deflection temperature, glass transition temperature and/or melt temperature to improve the wearability of the tissue pad, which is important when high clamping forces are employed because tissue pads wear faster at higher clamping forces than at lower clamping forces. Further benefits and expressions of this embodiment are disclosed in U.S. patent application Ser. No. 11/065,378, filed on Feb. 24, 2005 and commonly assigned to the assignee of the present application.
Although a single clamp arm is depicted, clamp arm 56 may comprise a distal T-shaped slot for accepting a T-shaped flange of distal clamp pad and a proximal wedged-shaped or dove tailed-shaped slot for accepting a wedge-shaped flange of a proximal clamp pad as is known and understood in the art. As would be appreciated by those skilled in the art, flanges and corresponding slots have alternate shapes and sizes to secure the clamp pads to the clamp arm. The illustrated flange configurations shown are exemplary only and accommodate the particular clamp pad material of one embodiment, but the particular size and shape of the flange may vary, including, but not limited to, flanges of the same size and shape. For unitary tissue pads, the flange may be of one configuration. Further, other methods of mechanically attaching the clamp pads to the clamp arm, such as rivets, glue, press fit or any other fastening means well know to the artisan are contemplated.
A first expression of a method for replacing clamp pads 58 would include one or more of the steps of: a) removing weld pin 56 b; b) removing clamp arm 56 from outer sheath 72; c) removing clamp pad 58 from the clamp arm 56; c) removing a pad insert 58 d from the clamp pad 58; d) inserting a clamp pad into a clamp arm 56; and e) engaging clamp arm 56 with outer sheath 72 via weld pin 56 b. In this removal and replacement process, the new clamp pad 58 inserted in step “d” may be of unitary TEFLON construction, may be of composite construction, may be multiple pieces of TEFLON or composite material or may contain a pad insert or any combination thereof. Pad insert may be a new pad insert or may be the pad insert from the “used” clamp pad.
A second expression of a method for replacing clamp pads 58 would include one or more of the steps of: a) opening flanges on clamp arm 56 (see
A third expression of a method for replacing a clamp pad having a base material and at-least-one pad insert material would include one or more of the steps of: a) removing the clamp pads from clamp arm 56; b) providing a new clamp pad having an opening at a proximal end thereof; c) inserting a pad insert sized to fit the opening into the opening; and d) attaching the clamp pad to the clamp arm.
Referring now to
Inner tube 76 translates along the longitudinal axis of outer sheath 72 and is grounded to the handle 70 through outer tube retainer 29. Legs 54 a,b on clamp arm 56 engage slots 54 c at the distal end of inner tube 76. The pivotal connection of clamp arm 56 to the inner and outer tubes 76, 72 provide more robustness to the end effector 81 and minimize failure modes due to excessive axial or torsional abuse loads. Further, the embodiment increases the effectiveness of the end effector 81 to provide clamp forces in excess of 5 lbs. Reciprocal movement of the actuating member 76, relative to the outer sheath 72 and the waveguide 80, thereby affects pivotal movement of the clamp arm 56 relative to the end-blade 79.
In one embodiment of the present invention, the inner tube 76 and outer sheath 72 are manufactured through rolled construction as is known and understood in the art. This rolled construction may result in significant cost savings over extrusion or other like manufacturing processes. Other manufacturing techniques, such as a drawn tube, are also contemplated herein.
Referring now to
Transducer 50 includes a first conductive ring 400 and a second conductive ring 410 which are securely disposed within the handpiece transducer body 50. In one expression of the current embodiment, first conductive ring 400 comprises a ring member, which is disposed between the transducer 50 and the horn 130. Preferably the first conductive ring 400 is formed adjacent to or as part of the flange member 160 within the cavity 162 and is electrically isolated from other electrical components. The first conductive ring 400 is anchored to and extends upwardly from a non-conductive platform or the like (not shown) which is formed within the transducer body 50. The first conductive ring 400 is electrically connected to the cable 22 (
The second conductive ring 410 of the transducer 50 similarly comprises a ring member that is disposed between the transducer body 150 and the horn 130. The second conductive ring 410 is disposed between the first conductive ring 400 and the horn 130 and therefore the first and second conductive rings 400, 410 are concentric members. The second conductive ring 410 is likewise electrically isolated from the first conductive ring 400 and other electrical components contained within the transducer 50. Similar to the first conductive ring 400, the second conductive ring 410 preferably is anchored to and extends upwardly from the non-conductive platform. It will be understood that the first and second conductive rings 400, 410 are sufficiently spaced from one another so that they are electrically isolated from each other. This may be accomplished by using one or more spacers 413 disposed between the first and second conductive rings 400, 410 or between the rings 400, 410 and other members within the transducer 50. The second conductive ring 410 is also electrically connected to the cable 22 (
In one expression of the current embodiment, the distal end of transducer 50 threadedly attaches to the proximal end of waveguide 80. The distal end of transducer 50 also interfaces with switch assembly 300 to provide the surgeon with finger-activated controls on surgical instrument 100.
With reference now to
With particular reference now to
A flex circuit 330 provides for the electromechanical interface between pushbuttons 311, 312 and the generator 30 via transducer 50. Flex circuit comprises two dome switches 332 and 334 that are mechanically actuated by depressing pushbuttons 311 or 312 respectively of corresponding pushbutton assembly 310. Dome switches 332 and 334 are electrical contact switches, that when depressed provide an electrical signal to generator 30 as shown by the electrical wiring schematic of
Flex circuit 330 is partially folded and is generally fixedly attached in handle assembly 68 so that dome switches 334 and 332 interface with backing surfaces on handle assembly 69 (not shown). Backing surfaces provide a firm support for the dome switches during operation, discussed below. Dome switches 334 and 332 may be fixedly attached to backing surfaces by any convenient method, such as, an adhesive. Flex circuit is secured to connector assembly 350 via alignment pins 354 on switch assembly 350 and corresponding alignment holes 338 on flex circuit 330. As is well appreciated by one skilled in the art various electrical constructions are available to provide electrical interface between the pushbuttons and the generator, which may include molded circuits or standard wire connections.
Layered on top of flex circuit is pushbutton assembly 310, which has a corresponding saddle-shape as flex circuit 330. Pushbutton assembly 310 comprises two pushbuttons, distal pushbutton 312 and proximal pushbutton 311 which have corresponding pressure studs 315 and 314 arranged in a rocker fashion. In one embodiment, push button assembly 310 comprises a rocker style pushbutton. Other types of switches, known to the skilled artisan, are equally applicable. Rocker pushbutton assembly 310 is rotationally attached to handle 70 to provide centering action to the pushbutton assembly 310. As is readily apparent, by depressing pushbuttons 311 and 312 the corresponding pressure studs 314 and 315 depress against corresponding dome switches 334 and 332 to activate the circuit illustrated in
Alternatively, the pushbuttons may be molded into the connector assembly 350 or into the handle assembly 68 to reduce the number of components and increase the reliability of the overall device. The pushbuttons may be attached through small cantilever sections, which allow for sturdy attachment of the pushbutton to the other components, while at the same time allowing for a low force to activate the pushbuttons.
In the foregoing embodiment of the present invention, switches 311 and 312 configured in such a way to provide an ergonomically pleasing grip and operation for the surgeon. Switches may be placed in the range of the natural swing of the surgeon's index or middle fingers, whether gripping surgical instrument 100 right-handed or left handed. Referring again to
In an alternate expression of the invention, trigger handle 34 and grip handle 70 have a soft-touch molded thermo plastic elastomer liner (not shown) on their inner surfaces defining openings 34 a and 68 a. Plastic liner provides comfort to the surgeon and prevents finger and hand fatigue. The plastic liner also provides an enhanced gripping surface between the handles and the surgeon's thumb and fingers. This is particularly advantageous for accepting multiple digit sizes of male and female surgeons and still providing a comfortable and positive gripping surface. Plastic liner be smooth or have contours molded onto the surface of liner, such as ribs. Other contours may be bumps, and peaks and valleys. Various other shapes and interfaces are within the scope of this invention as would be obvious to one skilled in the art.
Referring now to
Referring now to
In operation, torque wrench opening 502 is aligned with outer sheath 72 and guided along substantially the entire length of sheath 72. Torque wrench lip 503 engages the distal end of handgrip 70. Cantilever teeth 501 a slidably engage spline gears 29 a on outer tube retainer 29. Cam ramp 501 b slidably engages retainer cam ramps 29 b. Clockwise annular motion or torque is imparted to torque wrench 500 through paddles 504. The torque is transmitted through arms 501 and teeth 501 a to gears 29 a, which in turn transmit the torque to the waveguide 80 via insulated pin 27. When a user imparts 5-12 in-lbs. of torque and holds the handpiece 50 stationary, the ramps 501 b and 29 b cause the arms 501 to move or flex away from the centerline of wrench 500 ensuring that the user does not over-tighten the waveguide 80 onto horn 130 (
In another embodiment (not shown), the paddles and cantilever arm assembly may be separate components attached by mechanical means or chemical means such as adhesives or glue.
Referring now to
In one expression of the current embodiment, wave spring 94 has a spring constant about 43 pounds per inch. Wave spring 94 is preloaded to a force necessary to achieve the desired transection force, and is a function of the mechanical advantage of the clamp arm 56 coupling means and frictional losses in the device. In a second expression of the current embodiment, wave spring 94 is preloaded at about 13 pounds.
Referring now to
Referring now to
Clicker 339 is generally planar and made of a flexible plastic that adequately deflects when it engages trigger handle tab 34 a thereby providing an audible and/or tactile signal to the surgeon that there is full end effector 81 closure. Advantageously, tab 34 a strikes and deflects clicker 339 when trigger handle 34 is rotated from the full closure position and in the opposite direction thereby providing an audible and/or tactile signal to the surgeon that full closure of end effector 81 no longer exists. As would be appreciated by the skilled artisan, the indicating means may be either tactile, audible or visual or a combination. Various types of indicators may be used including dome switches, solid stops, cantilever springs or any number of mechanical or electrical switches known to those skilled in the art. Further various means may be used to provide feedback to the surgeon, including, but not limited to, lights, buzzers, and vibratory elements.
Preferably, the ultrasonic clamp coagulator apparatus described above will be processed before surgery. First, a new or used ultrasonic clamp coagulator apparatus is obtained and if necessary cleaned. The ultrasonic clamp coagulator apparatus can then be sterilized. In one sterilization technique the ultrasonic clamp coagulator apparatus is placed in a closed and sealed container, such as a plastic or TYVEK bag. Optionally, the ultrasonic clamp coagulator apparatus can be bundled in the container as a kit with other components, including a torque wrench. The container and ultrasonic clamp coagulator apparatus, as well as any other components, are then sterilized in any conventional medical sterilization technique, such as gamma radiation, x-rays, high-energy electrons or ETO (ethylene oxide). The sterilization kills bacteria on the ultrasonic clamp coagulator apparatus and in the container. The sterilized ultrasonic clamp coagulator apparatus can then be stored in the sterile container. The sealed container keeps the ultrasonic clamp coagulator apparatus sterile until it is opened in the medical facility.
While the present invention has been illustrated by description of several embodiments, it is not the intention of the applicant to restrict or limit the spirit and scope of the appended claims to such detail. Numerous variations, changes, and substitutions will occur to those skilled in the art without departing from the scope of the invention. Moreover, the structure of each element associated with the present invention can be alternatively described as a means for providing the function performed by the element. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims.