1 ULTRASOUND CATHETER HAVING PROTECTIVE FEATURE AGAINST BREAKAGE
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains to medical equipment, and more particularly, to a therapeutic ultrasound system for ablating obstructions within tubular anatomical structures such as blood vessels. The ultrasound system includes a protective feature that minimizes the introduction of debris into the patient’s vasculature if the ultrasound transmission member were to break, fracture or become dislodged during a medical procedure.
2. Description of the Prior Art
A number of ultrasound systems and devices have heretofore been proposed for use in ablating or removing obstructive material from blood vessels. Ultrasound catheters have been utilized to ablate various types of obstructions from blood vessels of humans and animals. Successful applications of ultrasound energy to smaller blood vessels, such as the coronary arteries, requires the use of relatively small diameter ultrasound catheters which are sufliciently small and flexible to undergo transluminal advancement through the tortuous vasculature of the aortic arch and coronary tree. However, because of its small diameter, the ultrasound transmission member which extends through such catheters is particularly susceptible to losses in the transmitted ultrasound energy, and breakage.
Breakage of ultrasound transmission members often occurs near the proximal end thereof, generally at the coupling between the ultrasound catheter coupling and the ultrasound transducer. This is believed to be because energy concentrations and stresses are highest at these points. Thus, any external forces applied to the ultrasound transmission member in this region may result in stresses exceeding the elastic limit of the ultrasound transmission member.
External forces may be inadvertently and undesirably applied to the ultrasound transmission member by pressing upon, pushing, pulling, torquing, bending or bumping the ultrasound transmission member coupling during use of the ultrasound catheter. Such forces when applied to the ultrasound catheter coupling area further result in limited ultrasound energy transmission through the ultrasound transmission member. If ultrasound energy is being transmitted by the ultrasound transmission member at the instant such forces are applied thereto, additional stresses occur which may result in breakage of the ultrasound transmission member.
Breakage of ultrasound transmission members can also occur near the distal end thereof, generally at the area of the smallest cross-section. Therefore, it is important that any debris resulting from the breakage of the ultrasound transmission member not be allowed to be introduced into a patient’ s vasculature during a medical procedure.
Thus, there still exists a need to protect against breakage of the ultrasound transmission member during a medical procedure.
SUMMARY OF THE DISCLOSURE
It is an object of the present invention to provide an ultrasound catheter system with a protective feature that prevents or minimizes the introduction of debris into the patient’s vasculature if the ultrasound transmission member were to break or fracture during a medical procedure.
In order to accomplish the objects of the present invention, there is provided an ultrasound catheter having an elongate flexible catheter body having a lumen extending longitudinally therethrough, and an ultrasound transmission member extending longitudinally through the lumen of the catheter body. The ultrasound transmission member has a proximal end that is coupled to a separate ultrasound generating device, and a distal end that terminates at the distal end of the catheter body, with at least a portion of the distal end of the ultrasound transmission member extending outside the lumen of the catheter body and beyond the distal end of the catheter body, and with the ultrasound transmission member directly attached to the catheter body via an attachment device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an ultrasound system according to the present invention.
FIG. 2 is a cross-sectional view of the distal end of an ultrasound catheter that can be used with the system of FIG. 1 according to one embodiment thereof.
FIG. 3 is a side sectional view of an ultrasound transmission member that can be used with the system of FIG. 1.
FIGS. 4-9 are cross-sectional views of the distal end of various ultrasound catheters that can be used with the system of FIG. 1 according to different embodiments thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following detailed description is of the best presently contemplated modes of carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating general principles of embodiments of the invention. The scope of the invention is best defined by the appended claims. In certain instances, detailed descriptions of well-known devices, compositions, components, mechanisms and methods are omitted so as to not obscure the description of the present invention with unnecessary detail.
FIG. 1 illustrates an ultrasound system according to the present invention for use in ablating and removing occlusive material inside the vessel of an animal or human. Referring to FIGS. 1 and 2, the ultrasound system includes an ultrasound catheter device 10 which has an elongate catheter body 11 having a proximal end 12, a distal end 14, and defining at least one lumen 15 extending longitudinally therethrough. The ultrasound catheter device 10 is operatively coupled at its proximal end 12, by way of aY-connector 18, a catheter knob 20, and a slide collar 22, to an ultrasound transducer 24. The ultrasound transducer 24 is connected to a signal generator 26, which can be provided with a foot actuated on-off switch 28. The signal generator 26 canbe supported by an IVpole 27. When the on-off switch 28 is depressed, the signal generator 26 sends an electrical signal to the ultrasound transducer 24, which converts the electrical signal to ultrasound energy. Such ultrasound energy subsequently passes through the catheter device 10 and is delivered to the distal end 14. A guidewire 25 may be utilized in conjunction with the catheter device 10, as will be more fully described below.
The catheter body 11 is formed of a flexible polymeric material such as nylon (PebaxTM) manufactured by Atochimie, Cour beVoie, Hauts Ve-Sine, France. The flexible catheter body 11 is preferably in the form of an elongate tube having one or more lumens extending longitudinally therethrough. The catheter body 11 defines a main lumen 15. Extending longitudinally through the main lumen 15 is an