Steerable ultrasound catheter

Airship Ultrasound Catheter

Background of the invention

The present invention relates generally to medical devices. More specifically, the present invention relates to ultrasonic catheter devices for the treatment of occlusive intravascular lesions.

Catheters that employ various types of ultrasonic transmission members have been used successfully for ablation or fragmentation of blockages in blood vessels. Specifically, ablation of the atherosclerotic plaque or thromboembolic obstructions of peripheral blood vessels such as the femoral arteries has been particularly successful. Various ultrasonic catheter devices have been developed for use in the ablation or removal of obstructive material from the blood vessels. For example, US Pat. Nos. 5,267,954 and 5,380,274, granted to an inventor of the present invention, describe ultrasonic catheter devices for the removal of occlusions. Other examples of ultrasonic ablation devices for removing blockages of blood vessels include those described in US Pat. Nos. 3,433,226 (Boyd), 3,823,717 (Pohlman, et al.), 4,808,153 (Parisi), 4,936,281 (Stasz), 3,565,062 (Kuris), 4,924,863 (Sterzer),

4,870,953 (Don Michael, et al.), And 4,920,954 (Alliger, et al.), As well as other patent publications W087-05739 (Cooper), W089-06515 (Bernstein, et al.), W090- 0130 (Sonic Needle Corp.), EP, EP316789 (Don Michael, et al.), DE3,821,836 (Schubert) and DE2438648 (Pohlman). However, although many ultrasound catheters have been developed, there are still attempts to find improvements.

Typically, an ultrasound catheter system for ablation of occlusive material includes three basic components: an ultrasonic generator, an ultrasound transducer, and an ultrasound catheter. The generator converts power from the grid into a high frequency current that is delivered to the transducer. The transducer contains piezoelectric crystals that, when excited by the high frequency current, expand and contract at high frequency. These small high-frequency expansions (relative to a transducer shaft and catheter) are amplified by the transducer horn to convert them into vibrational energy. The vibrations are then transmitted from the transducer through the ultrasonic catheter through an ultrasonic transmission member (or cable) that passes longitudinally through the catheter. The transmission member transmits the vibration energy to the distal end of the catheter where the energy is used for the ablation or fragmentation of a vascular obstruction.

To effectively reach the various sites for the treatment of intravascular occlusions, ultrasound catheters of the type described above typically have lengths of approximately 150 cm or longer. To allow the advancement of such ultrasound catheters through small and / or tortuous blood vessels such as the aortic arch, coronary vessels, and the peripheral vasculature of the lower extremities, the catheters (and their respective ultrasonic transmission cables) normally They must be small and flexible enough. Also, due to the attenuation of ultrasonic energy along the long and thin ultrasonic transmission cable, a sufficient amount of vibration energy must be applied at the proximal end of the cable to provide a desired amount of energy at the end. distal

However, improvements are always sought. For example, it remains a challenge to develop a catheter that is rigid enough to be push or "steerable" through the vasculature and yet flexible enough, at least along part of its length, to navigate the blood vessels Tortuous and small such as coronary arteries or tortuous peripheral vasculature. It is also sometimes difficult to manipulate the ultrasonic catheter devices currently available, for example, to twist or twist the proximal end of the catheter to move the distal end in a way that aids navigation through the vasculature. The passage of a guide wire through an ultrasonic catheter can also be improved, such that the guide wire does not interfere with, and can even improve, the fragmentation of vascular occlusions.

US 6,450,975 B1 refers to an ultrasound catheter. It comprises a catheter body having a proximal portion, a distal portion and a lumen, in which the distal portion is more flexible than the rest of the catheter body. It also comprises an ultrasonic transmission member that extends longitudinally through the lumen of the catheter body and has a proximal end and a distal end, the ultrasonic transmission member having a narrowing towards its distal end. It also comprises a distal head totally attached to the catheter body. It also comprises a connector to an ultrasonic transducer for mounting the guide wire to the ultrasonic transducer. The distal head also comprises a guide wire light that extends through the distal head. US 6,296,620 B1, US 6,508,781 B1, US 5,267,954 are other prior art documents. WO 98/51224 discloses an ultrasound catheter according to the preamble of claim 1.

Therefore, there is a need for improved ultrasonic catheter devices that provide ablation

or the fragmentation of vascular occlusions. Ideally, such ultrasound catheters would have a greater ability to navigate through small, tortuous blood vessels such as coronary arteries.

It would also be advantageous to have catheters that could be easily manipulated by a user. Ideally, such devices would allow the passage of a guide wire without interfering with, and perhaps even improving, the fragmentation of vascular obstructions. At least some of these objectives will be achieved by the present invention.

Brief Summary of the Invention

Ultrasound catheter devices provide improved fragmentation of blood vessel blockages. In general, ultrasound catheters include a flexible elongated catheter body with a

or more lights, an ultrasonic transmission member that extends longitudinally through the light of the catheter body, and a distal head coupled with the transmission member and located adjacent to the distal end of the catheter body to fragment occlusions.

Enhanced features include, but are not limited to, catheter bodies and ultrasonic transmission members with greater flexibility towards their distal ends, devices that concomitantly bend with one or more elbows in a guide wire and / or a vessel blood, a proximal shell coupled with an ultrasound catheter body to improve catheter body manipulation, a guide wire light configured to allow contact between a guide wire and an ultrasonic transmission member, distal heads with improved guide wire lights and the like.

In one aspect of the present invention, an ultrasound catheter is provided to fragment occlusions in the blood vessels having the characteristics of claim 1. The ultrasonic catheter generally includes a flexible elongated catheter body, an ultrasonic transmission member that extends longitudinally through the light of the catheter body, a distal head coupled with the distal end of the ultrasonic transmission member and adjacently arranged to the distal end of the catheter body, and at least one coupling member for coupling the ultrasonic transmission member with an ultrasonic energy source. The catheter body has a proximal portion, a distal portion and at least one lumen, the proximal portion being more rigid than the distal portion, the distal portion being more flexible near the distal end of the catheter body than near the proximal portion of the catheter body The ultrasonic transmission member has a proximal end and a distal end and is more flexible near its distal end than near its proximal end. Therefore, both the distal portion of the catheter body and the ultrasonic transmission member are more flexible towards the distal end of the device.

Increasing the flexibility of the catheter body and the ultrasonic transmission cable towards the distal end of the catheter device can be achieved by any suitable manufacturing process. In some embodiments, for example, the ultrasonic transmission cable, the catheter body, or both can be narrowed, such that the diameter of its cross section decreases distally. In one embodiment, for example, the cross-sectional diameter of a catheter body may vary from about 0.102 cm to about 0.178 cm along its proximal end to between about 0.076 cm and about 0.127 cm along its length. distal end, and the cross-sectional diameter of an ultrasonic transmission member may vary from about 0.051 cm to about 0.102 cm near its proximal end to between about 0.013 cm and about 0.038 cm near its distal end. Additionally or alternatively, the wall thickness of the catheter body may decrease from proximal to distal. For example, in one embodiment, the wall thickness of a catheter body can measure approximately 0.007 cm to approximately 0.020 cm along its proximal portion and approximately 0.005 cm to approximately 0.013 cm along its distal portion. In these or other embodiments, various combinations of materials can be used to give the catheter body, the transmission cable or both a desired flexibility profile. Providing an ultrasound catheter with a catheter body and an ultrasound transmission cable that both increase flexibility towards the distal end of the device will improve navigation of the distal end of the device through tortuous blood vessels. In one embodiment, for example, the distal portion of the device will be flexible enough to pass, without twisting, through at least 5 cm in length of a blood vessel having at least one curve and an inside diameter of between about 2 mm and approximately 5 mm. A "tortuous glass," for the purposes of this application, means that it has at least one elbow or curve, and bend or bend may have any angle or radius of curvature. In some embodiments, for example, at least one elbow in a vessel may have a radius of approximately 1.0 cm or less. In some cases, of course, a tortuous blood vessel will have multiple elbows or curves.

In another aspect of the invention, an ultrasound catheter for fragmenting blood vessel occlusions that can be guided along a guide wire from an access site in a patient's body to a target site adjacent to an occlusion. includes a flexible elongated catheter body, an ultrasonic transmission member that extends longitudinally through the light of the catheter body, a distal head coupled with the distal end of the ultrasonic transmission member and disposed adjacent to the distal end of the catheter body, and at least one coupling member for coupling the ultrasonic transmission member with an ultrasonic energy source. In this aspect, the catheter body has a proximal portion, a distal portion and at least one light, the proximal portion has a cross-sectional diameter larger than the distal portion, the proximal portion is rigid enough to push the distal portion through of a blood vessel that has at least one elbow, and the distal portion is flexible enough to pass through the elbow in the vessel

blood The ultrasonic transmission member has a proximal end and a distal end, the diameter of the cross section of the ultrasonic transmission member is smaller near its distal end than near its proximal end, and a distal portion of the transmission member of Ultrasound is flexible enough to pass through the elbow in the blood vessel. Again, in some embodiments, the wall of the catheter body may be thinner along the distal portion than along the proximal portion.

In another aspect of the present invention, an ultrasound catheter for fragmenting occlusions in the blood vessels that can be guided from an access site in a patient's body to a target site adjacent to an occlusion includes a flexible elongated catheter body that it has a proximal portion, a distal portion and at least one light, an ultrasonic transmission member that extends longitudinally through the light of the catheter body, a distal head coupled with the distal end of the ultrasonic transmission member and disposed adjacent to the distal end of the catheter body, and at least one coupling member for coupling the ultrasonic transmission member with an ultrasonic energy source. In this aspect, the distal portion of the catheter body is more flexible near a distal end of the catheter body than near the proximal portion of the catheter body, and the ultrasonic transmission member is more flexible near its distal end than near its proximal end. In addition, the distal portion of the catheter body and the ultrasonic transmission member are sufficiently flexible to adapt concomitantly with at least one elbow in a guide wire extended through the at least one light.

By "concomitantly adapting" it is meant that the catheter body and the ultrasonic transmission member are adapted to at least one elbow in the guide wire such that the catheter body, the transmission member and the guide wire they curve at an approximately similar angle. In some embodiments, the distal portion of the catheter body and the ultrasonic transmission cable are flexible enough to concomitantly accommodate multiple elbows in the guide wire. Also in some embodiments, the distal portion of the catheter body and the ultrasound transmission member are flexible enough to concomitantly accommodate multiple elbows in a blood vessel. In several embodiments, the catheter can be advanced on a guide wire, a guide wire can be passed through the catheter body, or the catheter body, the ultrasonic transmission cable and the guide wire can be advanced through a vessel blood simultaneously. Therefore, in several embodiments, the distal portion of the catheter body, the ultrasonic transmission cable and the guide wire can be passed together or sequentially through the multiple elbows in the blood vessel while concomitantly adapting to The multiple elbows.

In another aspect of the present invention, an ultrasound catheter for fragmenting occlusions in the blood vessels that can be guided from an access site in a patient's body to a target site adjacent to an occlusion includes a flexible elongated catheter body that it has a proximal portion, a distal portion and at least one light, an ultrasonic transmission member that extends longitudinally through the light of the catheter body, a distal head coupled with the distal end of the ultrasonic transmission member and disposed adjacent to the distal end of the catheter body, and at least one coupling member for coupling the ultrasonic transmission member with an ultrasonic energy source. In this aspect, the distal portion of the catheter body has at least one elbow, and at least one lumen, the proximal portion of the catheter body is more rigid than the distal portion, and the distal portion is more flexible near a distal end. of the catheter body that near the proximal portion of the catheter body. The ultrasonic transmission member is more flexible near its distal end than near its proximal end, the ultrasonic transmission member fits at least one elbow in the distal portion of the catheter body, and the distal portion of the body of Catheter and ultrasonic transmission member are flexible enough to concomitantly fit at least one elbow in a guide wire.

In yet another aspect of the present invention, an ultrasound catheter for fragmenting occlusions in the blood vessels that can be guided from an access site in a patient's body to a target site adjacent to an occlusion includes an elongated flexible catheter body. having a proximal portion, a distal portion and at least one light, an ultrasonic transmission member that extends longitudinally through the light of the catheter body, a distal head coupled with the distal end of the ultrasonic transmission member and disposed adjacent to the distal end of the catheter body, and at least one coupling member for coupling the ultrasonic transmission member with an ultrasonic energy source. In this aspect, the catheter body includes a guide wire tube disposed within the light, and the proximal body portion is more rigid than the distal portion. The guide wire tube includes at least one opening within the catheter body to provide contact between a guide wire that extends through the guide wire tube and the ultrasonic transmission member.

Allowing a guide wire to contact the ultrasonic transmission member can facilitate the passage of the guide wire into or through a vascular occlusion, by allowing a portion of the ultrasonic energy transmitted by the transmission member to be transferred to the guide wire. In various embodiments, the guide wire may contact the transmission member near the proximal end of the catheter device, near the distal end, near the middle, or some combination thereof. In some embodiments, the guide wire tube includes two openings in the catheter body, to allow the transmission member to pass through the tube. Any other configuration to allow contact between a guide wire and the ultrasonic transmission member is also

contemplate

In another aspect of the present invention, an ultrasound catheter for fragmenting occlusions in the blood vessels that can be guided from an access site in a patient's body to a target site adjacent to an occlusion includes a flexible elongated catheter body that it has a proximal portion, a distal portion and at least one light, an ultrasonic transmission member that extends longitudinally through the light of the catheter body, a distal head coupled with the distal end of the ultrasonic transmission member and disposed adjacent to the distal end of the catheter body, and at least one coupling member for coupling the ultrasonic transmission member with an ultrasonic energy source. In this aspect, the distal head includes a guide wire opening in the center of its distal end and a guide wire light extending through the distal head. The guide wire light, in turn, has a different longitudinal axis than the longitudinal axis of the catheter body.

Having a guide wire light that exits the center of the distal head is advantageous for advancing the guide wire as well as the catheter device. Tilting the guide wire light away from the longitudinal axis of the catheter body allows a guide wire and the ultrasonic transmission member to pass through a narrower catheter body, thereby decreasing the diameter of the catheter device and facilitating passage to through tortuous glasses. In some embodiments, the guidewire light in the distal head includes a cavity in which a distal end of a guidewire tube of the catheter body is disposed. In some embodiments, the cavity extends through the distal end of the distal head, such that the distal end of the guide wire tube is level with the distal end of the distal head. In other embodiments, the cavity partially extends through the distal head, such that the distal end of the guide wire tube is disposed proximal to the distal end of the distal head.

In another aspect of the present invention, an ultrasound catheter for fragmenting occlusions in the blood vessels that can be guided from an access site in a patient's body to a target site adjacent to an occlusion includes a flexible elongated catheter body that it has a proximal portion, a distal portion and at least one light, an ultrasonic transmission member that extends longitudinally through the light of the catheter body, a distal head coupled with the distal end of the ultrasonic transmission member and disposed adjacent to the distal end of the catheter body, and at least one coupling member for coupling the ultrasonic transmission member with an ultrasonic energy source. In this aspect of the invention, the at least one coupling member comprises a housing fixedly coupled with the proximal end of the catheter body such that the torque applied to the housing is transmitted along the catheter body. to its distal portion.

In yet another aspect of the description, a procedure for fragmenting an occlusion in a blood vessel involves: advancing an ultrasound catheter through a blood vessel that has at least one elbow, adapting the catheter concomitantly to at least one elbow , in which the advance includes contacting an ultrasonic transmission member of the ultrasonic catheter with a guide wire in one or more locations within the catheter; position a distal end of the ultrasound catheter adjacent to an occlusion in the blood vessel; and transmitting ultrasound energy to the ultrasonic transmission member to fragment the occlusion into multiple occlusion fragments, wherein the transmission includes transmitting ultrasound energy to the guide wire. Optionally, the procedure may also include removing at least some of the blood vessel occlusion fragments through the ultrasound catheter. In some examples, the ultrasound catheter is advanced along the guide wire. Alternatively, the guide wire can be passed through the catheter, or the catheter and guide wire can be advanced together through the blood vessel. Positioning may also involve advancing the ultrasonic catheter and the guide wire along multiple elbows in the blood vessel, where a catheter body of the catheter, the ultrasonic transmission member and the guide wire are concomitantly adapted to multiple elbows. The elbows can have any suitable angle or radius of curvature. In one embodiment, for example, one or more elbows may have a radius of approximately 1.0 cm or less. The procedure may also involve applying a radial force to a proximal housing of the ultrasound catheter to radially rotate the distal end of the ultrasound catheter in the blood vessel.

Other specific aspects and embodiments of the invention will be described below, with reference to the figures in the accompanying drawings.

Brief description of the drawings

FIG. 1 is a perspective view of an ultrasonic catheter system that includes an ultrasonic catheter device and an ultrasonic energy source according to an embodiment of the present invention;

FIG. 1A is a side view of the cross section of an ultrasonic catheter device according to an embodiment of the present invention;

FIG. 2 is a perspective view of a human heart and an ultrasonic catheter device, showing a possible path along which a device can be advanced according to an embodiment of the present

invention;

FIG. 3 is a side view of the cross section of a portion of an ultrasonic catheter device not according to an embodiment of the present invention;

FIG. 4 is a side view of the cross section of a distal portion of an ultrasonic catheter device and a guide wire not according to an embodiment of the present invention;

FIG. 5 is a side view of the cross section of a distal portion of an ultrasonic catheter device and a guide wire according to an embodiment of the present invention;

FIG. 6 is a side view of the cross section of the distal end of the ultrasonic catheter device and a guide wire shown in FIG. 5;

FIG. 7 is a side view of the cross section of a distal end of an ultrasonic catheter device and a guide wire according to an embodiment of the present invention; and

FIG. 8 is a perspective view of an ultrasonic catheter device having a fixed proximal housing according to an embodiment of the present invention.

Detailed description of the invention

The ultrasonic catheter devices of the present invention generally provide an improved treatment of occlusive intravascular lesions. Catheter devices generally include a catheter body, an ultrasonic energy transmission member disposed within the catheter body and a distal head coupled with the energy transmission member and disposed adjacent to the distal end of the catheter body. The ultrasonic transmission member transmits ultrasound energy from an ultrasound transducer to the distal head, causing the head to vibrate and, therefore, fragment vascular occlusions. Several improved features of such ultrasonic catheter devices are described more fully below.

Referring now to FIG. 1, an embodiment of an ultrasonic catheter system 20 conveniently includes an ultrasonic catheter device 10, which includes a proximal end connector 12 for coupling the device 10 with an ultrasonic transducer 14, and an ultrasonic generator 16 coupled with the transducer 14 and an on / off switch operated with the foot 18 to provide ultrasound energy to the transducer 14 and, therefore, to the ultrasonic catheter 10. In general, the catheter 10 includes an ultrasonic transmission member, or cable (not shown), to transmit energy from the transducer 14 to a distal head 26 of the catheter 10. In some embodiments, the transducer 14 further includes a device clamping 15 to improve catheter coupling 10 to transducer 14. System components 20 may be coupled by any suitable means, such as connection cables of any type, wireless connections or the like.

In addition to the proximal connector 12, the ultrasonic catheter device 10 may include one or more other additional components, such as a Y-connector 11 or the like to provide access for irrigation, the passage of the guide wire, aspiration or the like. Some embodiments of the device include a monorail guide wire 13, some include a proximal guide wire hole 17 for delivery via guide wire, and some embodiments include both. In some embodiments, the Y-connector may include an irrigation orifice, to provide access to an irrigation tube 24. The irrigation tube 24, in some embodiments, can be used to introduce one or more fluids, apply vacuum, or both. Generally, the catheter device 10 may include any suitable number of lateral arms or holes for the passage of a guide wire, infusion and / or removal of irrigation fluid, dye and / or the like, or any other suitable hole or connection. Also, the ultrasonic catheters 10 of the present invention can be used with any suitable proximal device, such as any suitable ultrasonic transducer 14, ultrasonic generator 16, coupling device (s) and / or the like. Therefore, exemplary Figure 1 and any following description of proximal devices or systems for use with ultrasonic catheters 10 should not be construed as limiting the scope of the present invention as defined in the appended claims.

Referring now to Figure 1A, a side view of the cross section of an embodiment of the ultrasonic catheter device 10 is shown. In general, the ultrasonic catheter 10 suitably includes an elongated catheter body 22 with a transmission member of ultrasound 24 arranged longitudinally through a catheter light 21 and terminates in a distal head (not shown). The catheter body 22 is generally a flexible, elongated tubular member, having any suitable diameter and length to reach a vascular occlusion for treatment. In one embodiment, for example, catheter body 22 preferably has an outside diameter of between about 0.5 mm and about 5.0 mm. In other embodiments, such as in catheters intended for use in relatively small vessels, the catheter body 22 may have an outside diameter of between about 0.25 mm and about 2.5 mm. The body of

Catheter 22 can also have any suitable length. As briefly described above, for example, some ultrasound catheters have a length in the range of approximately 150 cm. However, any other suitable length can be used without departing from the scope of the present invention. Examples of catheter bodies similar to those that can be used in the present invention are described in US Pat. Nos. 5,267,954 and 5,989,208, referred to above.

In some embodiments, catheter body 22 is made of a polymeric material. Sometimes, the polymer will have a desired amount of flexibility, such as in an embodiment where the catheter body 22 is made of a polymer having a flexural modulus of less than about 160 psi (1103.16 kPa). In some embodiments, such a polymer will be one of any number of polyether block amides, although, of course, other polymers can be used. In some embodiments, such polyether block amides may have a Shore D hardness value ranging from about 55 to about 75, while in other embodiments they may have a Shore D hardness value ranging from about 25 to about 55. In In some embodiments, the polymeric material includes up to about 5 percent by weight of a dye.

In most embodiments, the ultrasonic transmission member 24, which may comprise a cable, waveguide or the like, extends longitudinally through the light of the catheter body 21 to transmit ultrasound energy from the ultrasound transducer 14 (Fig. 1) to the distal end of catheter 10. The ultrasonic transmission member 24 may be formed of any material capable of effectively transmitting ultrasound energy from the ultrasonic transducer 14 to the distal end of the catheter body 22, including but not limited to metals such as pure titanium or aluminum, or alloys of titanium or aluminum. According to one aspect of the invention, all or a portion of the ultrasonic transmission member 24 may be formed of one or more materials having super elastic properties. Such material (s) should preferably exhibit superelasticity consistently within the range of temperatures normally found by the ultrasonic transmission member 24 during operation of the ultrasonic catheter apparatus 10. For example, in some embodiments, the material is an alloy that has a tensile strength of between about 170,000 psi (1172108.73 kPa) and about 250,000 psi (1723689.32 kPa). In some embodiments, the alloy has an elongation of between about 7% and about 17%. For example, in some embodiments the alloy is a nickel-titanium alloy having a nickel content of between about 50.50 and about 51.50 by atomic weight.

The use of superelastic metal alloys in ultrasonic transmission members is described in US Patent No. 5,267,954, referred to above. Examples of superelastic metal alloys that can be used are described in detail in US Patent Nos. 4,665,906 (Jervis); US 4,565,589 (Harrison); US 4,505,767 (Quin); and US

4,337,090 (Harrison), to whose full descriptions reference is made here to the extent that they describe the compositions, chemical properties, and the behavior of specific metal alloys that are super elastic within the temperature range in which the member of ultrasonic transmission 24 of the present invention, Each and every one of the superelastic metal alloys can be used to form the ultrasonic transmission member 24 of the present invention. In some embodiments, for example, the alloy has a superelastic temperature range of about 10 degrees Celsius to about 50 degrees Celsius.

With continued reference to Figure 1A, an embodiment of the proximal end connector 12 suitably includes a housing 42 with a hollow inner bore 44. The bore 44 may have a uniform internal diameter along its length or, alternatively, may have multiple segments, such as a proximal segment 47, a middle segment 45 and a distal segment 49, each of which may surround one or more different components of the proximal end connector 12. In general, the proximal segment 47 of the perforation 44 is configured to allow coupling with the ultrasonic transducer 14 (not shown) through any suitable coupling means, such as a snap fit, complementary threads or the like. The proximal segment 47 includes a sonic connector 52 for transmitting vibration energy from the transducer 14 to the ultrasonic transmission member 24. The sonic connector 52 can be held inside the housing 42 by any suitable means. In some embodiments, for example, a pin may extend through the sonic connector 52 to hold it inside the housing 42. In another embodiment, the sonic connector 52 may be fixed within the housing 42 by means of a cavity in the housing 42 .

The middle segment 45 of the bore 44, in some embodiments, may surround a portion of the sonic connector 52, while in other embodiments, the sonic connector 52 may be housed only within the proximal segment 47. The sonic connector 52 is coupled with the proximal end of the ultrasonic transmission member 24 by any means suitable for transmitting ultrasound energy to the transmission member 24 from the transducer 14. Absorption members 50, such as o-rings, surround a portion of the ultrasonic transmission member 24 to provide transverse vibration absorption. The absorption members 50 may be used in any number or combination and have any suitable size and configuration, depending on the desired level of vibration absorption or damping. Alternatively or additionally, other damping structures may be used. Therefore, the invention is not limited to the combination shown in Figure 1A.

The distal segment 49 of the perforation 44 typically surrounds a portion of the ultrasonic transmission member 24 and may also contain one or more additional sets of absorption members 50. The distal segment 49 may also contain a portion of a Y-connector 11, which is coupled with the distal end of the housing 42. The coupling of the Y-connector 11 with the distal end of the housing 42 can be carried out through complementary threads, pressure adjustment, or any other suitable means. A light of the Y-connector 48 of the Y-connector 11 allows the passage of the ultrasonic transmission member 24 and is in fluid communication with the light of the catheter body 21.

In general, a pressurized fluid such as a coolant can be infused through a side arm 13 of the Y connector, through the light of the Y connector 48 or through the light of the catheter body 21 to flow out of one or more fluid outlet openings in the distal head 26. The temperature and flow rate of such a coolant can be specifically controlled to maintain the temperature of the ultrasonic transmission member 24 at a desired temperature within its optimum working range. In particular, in embodiments of the invention in which the ultrasonic transmission member 24 is formed of a metal alloy having optimal physical properties (eg, super-elasticity) within a specific range of temperatures, The temperature and flow rate of infused coolant through the fluid infusion side arm 13 can be specifically controlled to maintain the temperature of the ultrasonic transmission member 24 within a temperature range in which it exhibits its most desirable physical properties. For example, in embodiments of the invention in which the ultrasonic transmission member 24 is formed of a memory alloy so that it exhibits superelasticity when it is in its martensitic state, but loses superrelasticity in the transition to an austenitic state, it will be desirable to adjust the temperature and flow rate of the infused coolant through the fluid infusion side arm 13 to maintain the shape memory alloy of the ultrasonic transmission member 24 within a temperature range in which the alloy will remain in its martensitic state and will not change to the austenitic state. The temperature at which such shape memory alloys change from a martensitic state to an austenitic state is known as the "martensitic transition temperature" of the material. Therefore, in these embodiments, the fluid infused through the side arm 13 will be at such a temperature, and will be infused at such a rate, that the shape memory alloy of the ultrasonic transmission member 24 is kept below its Martensitic transition temperature

Referring now to Figure 2, an ultrasound catheter device 100 may be used to treat one or more coronary arteries CA in a human heart H. Some embodiments include a flexible distal portion, configured to navigate one or more elbows 102 in a coronary artery CA or another vessel. In some embodiments, catheter device 100 will be placed in an AC coronary artery or other vessel by advancing it through (or along) a guide wire 104. Some embodiments may also include or be used with a guide catheter 106.

As mentioned earlier, a "tortuous blood vessel," for the purposes of this application, means a vessel that has at least one elbow (which can also be referred to as a "curve" or the like), which has any angle of curvature. In some cases, of course, the tortuous vessels also have relatively small internal diameters and multiple elbows, and various embodiments of the ultrasonic catheter device 100 are configured to navigate multiple elbows in a vessel. In some embodiments, the ultrasonic catheter device 100 is configured to accommodate one or more elbows in a vessel so that two or more components of the device are concomitantly bent with each other. For example, in some embodiments, when the device 100 extends through an elbow in a vessel, an ultrasonic transmission member and a catheter body of the device 100 will bend at approximately the same angle. In some embodiments, the ultrasonic transmission member, the catheter body and a guide wire that extends through the catheter can all be concomitantly bent to fit an elbow in a blood vessel. Such concomitant flexion contrasts with some prior art devices, in which the ultrasound transmission member, for example, is relatively stiffer than a distal portion of the catheter body, so that when the device is placed on an elbow in a blood vessel, the catheter body bends at an angle sharper than the transmission member.

Referring now to Figure 3, in one example an ultrasonic catheter device 110 of the present invention includes a catheter body 116 having a proximal portion 112 and a distal portion 114, an ultrasonic transmission member 118, and a distal head 111. As described above, the catheter body 116, the transmission member 118 and the distal head 111 can be manufactured from any suitable material (s) and can have any of several suitable configurations, dimensions, and the like. In fact, Figure 3 is not drawn to scale, and the distal portion 114, for example, may be relatively much longer than as shown in Figure 3.

The proximal portion 112 of the catheter body 116 is generally more rigid than the distal portion 114, such proximal portion 112 is used to push or direct, and the distal portion 114 is flexible enough to navigate through a tortuous blood vessel to reach A place of occlusion. The difference in stiffness / flexibility can be achieved using different materials for the different portions, by configuring the proximal portion 112 with a

wall thicker than the distal portion 114, giving the proximal portion 112 a larger outside diameter, any combination thereof, or any other suitable technique. In some embodiments, the proximal portion 112 and the distal portion 114 are made of a single piece of material, or an extrusion, while in other embodiments two or more pieces of material may be joined together. The ultrasonic transmission member 118 also becomes more flexible (less rigid) towards its distal end. This is typically achieved by narrowing the transmission member 118, and the narrowing can be gradual, as shown in Figure 3, or can be achieved in a

or more less gradual stages. By providing the catheter body 116 and the ultrasonic transmission member 118 with progressively increasing flexibility towards the distal end, the catheter device 110 can provide greater "pushing capacity" or "maneuverability", while also facilitating navigation of tortuous vessels with the distal portion 114.

Referring now to Figure 4, another example of an ultrasonic catheter device 120 includes a catheter body 126, an ultrasonic transmission member 128 and a guide wire tube 124 disposed within the body 126, and a distal head coupled with the ultrasonic transmission member 121. The guide wire tube 124 may enter the catheter body 126 at any suitable location and may extend distally to, partially through, or completely through the distal head 121, as will be explained more fully below. In one embodiment, the guide wire tube 124 includes at least one opening 125 disposed within the catheter body 126, to allow a guide wire 122 to contact the ultrasonic transmission member 128 128 in one or more places. In the embodiment shown, the guide wire tube 124 includes two openings 125 to allow the ultrasonic transmission member 128 to pass through the tube 124. Any other suitable opening (s) are also contemplated within the scope of the invention. By allowing the guide wire 122 to contact the ultrasonic transmission member 128, an amount of ultrasonic energy can be transferred from the transmission member 128 to the guide wire 122. This transferred energy can vibrate the guide wire 122, and such energy of vibration may increase the ability of guide wire 122 to pass through a vascular occlusion. In many procedures, it is often advantageous to penetrate or pass through an occlusion with the guide wire 122, and using the ultrasonic energy transferred to the guide wire 122 from the transmission member 128 will improve such procedures.

Referring now to Figures 5 and 6, another embodiment of an ultrasonic catheter device 130 suitably includes a catheter body 136, an ultrasonic transmission member 138 and a guide wire tube 134 disposed within the catheter body 136, and a distal head 131 coupled with the distal ends of the transmission member 128 and the guide wire tube 134. In these embodiments, the distal head 131 includes a guide wire light 135. The guide wire 135 135 has a cavity at its proximal end to accept the distal end of the guide wire tube 134. In alternative embodiments, the distal head 131 may not include a cavity, and the guide wire tube 134 may rest on the proximal end of the distal head 131, or the cavity may extend completely through the distal head 131, so that the tube of guide wire 134 extends completely through the distal head 131 and is level with the distal end of the distal head 131. Also in the embodiment depicted in Figures 5 and 6, the guide wire light 135 of the distal head 131 has a longitudinal axis 139 that is not parallel to the general longitudinal axis 137 of the catheter device 130. Therefore, at least a portion distal of the guide wire tube 134 is also arranged on the longitudinal axis 139 which is not parallel to the longitudinal axis 137 of the catheter device 130. At the same time, the guide wire light 135 of the distal head 131 approximately exits at the center of the distal end of the distal head 131. Typically, it is advantageous to have a guide wire outlet 132 approximately at the center of the distal head 131, to facilitate tracking of catheter device 130 along guide wire 132. It can also be advantageous, however, to move the guide wire tube 134 relative to the catheter body 136, so that the guide wire tube 134 and the ultrasonic transmission member 138 can fit into a catheter body having a smaller internal diameter. Of course, it is easier to advance smaller diameter catheters through the tortuous vasculature.

In general, any of the coupled components described above may be coupled by any suitable means, such as adhesives, complementary threaded members, press fittings, and the like. For example, the distal head 131 may be coupled with the ultrasonic transmission member 138, the guide wire tube 134, and / or the catheter body 136 with any suitable adhesive substance or by welding, bonding, pressure adjustment, adjustments threaded or similar. Adhesives may include, but are not limited to cyanoacrylate adhesives (eg, Loctite ™, Loctite Corp., Ontario, Canada or Dron Alfa ™, Borden, Inc., Columbus, OH.) Or polyurethane (eg, Dymax ™, Dymax Engineering Adhesive, Torrington CT). Some embodiments may also include one or more anchor members to further secure the distal head 131 to the ultrasonic catheter device 130. Examples of such anchor members are described more fully in Application No. 10/410617, referred to above.

Referring now to Figure 7, another embodiment of an ultrasonic catheter device 140 includes a catheter body 146, an ultrasonic transmission member 148, a guide wire tube 144 and a distal head 141 having a cable light guide 145. In this embodiment, as mentioned briefly above, the guidewire light 145 is configured such that the guidewire tube 144 extends through the entire length of the distal head 141 and ends level with the distal end of the distal head 141. Generally, the distal head 141 and the guide wire light 145 may have any size, shape, configuration, dimension and the like that are suitable, and the invention is in no way limited by the embodiments shown.

Referring now to Figure 8, some embodiments of an ultrasonic catheter device 150 include a proximal housing 152 that is fixedly coupled with a catheter body 156. 5 The housing 152 may be a handle, a coupling member for coupling the device 150 to an ultrasonic transducer, or any other suitable proximal device to allow a user to manipulate the catheter device 150. By providing fixed coupling between the housing 152 and the catheter body, a proximal rotational force 155a (or torque, or torque) applied in the housing 152 will be transmitted to the catheter body 156 to cause the distal end of the catheter body 156 and the distal head 151 rotate 155b. It has been discovered that applying a pair,

10 Twisting or rotating the ultrasonic catheter device 150 may facilitate navigation of the device through the tortuous vasculature and / or the dissolution of a vascular occlusion using the device.

WO 2005/053769

fifteen Although the invention has been described above with specific reference to the various embodiments and examples, it should be understood that various additions, modifications, deletions and alterations to such embodiments can be made without departing from the scope of the invention as defined by the appended claims. Accordingly, it is intended that all reasonably foreseeable additions, deletions, alterations and modifications be included within the scope of the invention as defined in the following claims.