Therapeutic ultrasound system

E11187071

11-08-2014

DESCRIPTION

Therapeutic Ultrasound System

5 Background of the invention

1. Field of the Invention

The present invention relates to medical equipment, and more particularly, to an ultrasound therapeutic system 10 for ablating obstructions within tubular anatomical structures such as blood vessels.

two. Description of the prior art

So far, several ultrasound systems and devices have been proposed for use when submitting

fifteen ablation or removal of obstructive material from blood vessels. However, all these systems and devices generally encounter some problems that do not always adequately address these systems and devices.

A first type of problem refers in general to the efficient transmission of ultrasound energy from a source

twenty of ultrasound to the distal tip of the device where ultrasound energy is applied to ablate or remove obstructive material. Since the ultrasonic source, such as a transducer, is usually located outside the human body, it is necessary to supply the ultrasonic energy over a large distance, such as approximately 150 cm, along an ultrasonic transmission wire from the source to the distal tip. The attenuation of acoustic energy along the length of the transmission wire means that the

25 energy that reaches the distal tip. To ensure that sufficient energy reaches the distal tip, a greater amount of energy must be supplied along the transmission wire from the source to the distal tip. This increase in energy transmission along the transmission wire can increase the fatigue experienced by the transmission wire in certain critical locations, such as in the connection between the transducer and the transmission wire.

30 In addition to the above, it is important to be able to conveniently connect and disconnect the ultrasonic transmission element of the transducer without creating unnecessary tensions in the ultrasonic transmission wire, nor weakening the ultrasonic transmission wire. Since the transducer is a non-sterile unit and the ultrasonic transmission wire is a sterile unit, a transducer with numerous ultrasonic transmission wires can be used

35 different in numerous different procedures.

Therefore, there is also a need to provide a separable connection between the ultrasonic transmission wire and the transducer that can effectively transmit ultrasonic energy while maintaining the integrity of the ultrasonic transmission wire.

40 A second type of problem refers to the need to precisely place the ultrasound device inside a patient's vasculature, and in particular, when the vasculature contains smaller and more tortuous vessels. To address this need, flexible and low profile ultrasound devices have been provided that allow the device to navigate through small, tortuous vessels. However, these devices do not

Four. Five They have been completely satisfactory in meeting these navigation needs.

A third type of problem refers to the removal of particles that occur when the obstructive material is ablated or disintegrated. It is important that these particles be removed from the patient's vascular system to avoid distal embolization and other clinical complications.

fifty Therefore, there is still a need for improved ultrasound systems that have catheters or ultrasound devices that address the problems mentioned above.

EP 0 820 728 A2 refers to an ultrasonic angioplasty catheter device and discloses

55 the features according to the preamble of claim 1. This device refers to a ultrasonic wire catheter comprising a flexible tubular catheter body having a proximal end, a distal end, and a light extending longitudinally therethrough, an ultrasonic transmission element that extends longitudinally through the light of the catheter body, the ultrasonic transmission element having a proximal end and a distal end that is placed at the distal end of the catheter body,

60 a proximal connector placed at the proximal end of the ultrasonic transmission element for connecting the ultrasonic transmission element to a separate ultrasonic generating device, and a front element having a perforation housing the ultrasonic transmission element, and a grip splint substantially surrounding the ultrasonic transmission element to dampen the transverse movements of the ultrasonic transmission element. Documents DE 40 42 435 C2 and US 5,255,669 are documents

65 Additional prior art.

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Description Summary

The terms "ultrasonic transmission wire" and "ultrasonic transmission element" will be used interchangeably herein and are intended to refer to the same element.

An object of the present invention is to provide an ultrasonic device that provides an improved connection between the ultrasonic transmission element and the transducer.

Another object of the present invention is to provide an ultrasonic device that has a separable connection between the ultrasonic transmission element and the transducer.

Still another object of the present invention is to provide an ultrasound device with a distal end that can effectively navigate smaller and tortuous vessels.

Still another object of the present invention is to provide an ultrasound device that effectively removes particles from the patient's vascular system.

In order to achieve the objects of the present invention, an ultrasonic catheter with the features according to claim 1 is provided. In one example, the distal end of the catheter body may be deflected. The ultrasonic system of the present invention can incorporate one of several embodiments of sonic connectors that connect the ultrasonic transmission element to an ultrasonic transducer. The ultrasonic catheter of the present description also provides a procedure for inverse irrigation and particle removal.

Brief description of the drawings

Fig. 1 is a perspective view of an ultrasound system according to the present description.

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.

Fig. 3 is a cross-sectional view of the distal end of another ultrasonic catheter that can be used with the system of fig. 1.

Fig. 4 is a cross-sectional view of the catheter of fig. 3 shown with the distal end deviated.

Fig. 5 is a cross-sectional view of an embodiment of a sonic connector assembly that can be used with the system of fig. 1.

Fig. 6 is an enlarged cross-sectional view of the sonic connector in fig. 5.

Figs. 7-11 are cross-sectional views of different embodiments of sonic connector assemblies that can be used with the system of fig. 1.

The examples shown in Figures 5, 6, 7 and 11 are not part of the invention.

Detailed description of the preferred embodiments

The following detailed description is one of the best ways currently contemplated for carrying out the invention. This description is not to be taken in a limiting sense, but is merely made in order to illustrate the general principles of the embodiments of the invention. The scope of the invention is best defined by the appended claims. In certain cases, detailed descriptions of well-known devices, compositions, components, mechanisms and procedures are omitted so as not to complicate the description of the present invention with unnecessary details.

Fig. 1 illustrates an ultrasound system according to the present invention for use in ablation and removal of occlusive material within the vessel of an animal or human being. The ultrasound system includes an ultrasonic catheter device 10 having an elongated catheter body 12 having a proximal end 14, a distal end 16 and defining at least one longitudinally extending light therethrough. The ultrasonic catheter device 10 is operatively coupled, via a proximal connector assembly 20, to an ultrasonic transducer 22. The ultrasonic transducer 22 is connected to a signal generator 24. The signal generator 24 may be provided of an on-off switch 26 operated with the foot. When the on-off switch 26 is pressed, the signal generator 24 sends an electrical signal to the ultrasonic transducer 22, which converts the electrical signal into ultrasonic energy. Such ultrasound energy subsequently passes through catheter device 10 and is supplied to distal end 16. A guidewire 28 may be used in conjunction with catheter device 10, as will be described further.

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completely below.

Fig. 2 illustrates a non-limiting configuration for the distal end 16 of the catheter body 12 of the catheter device 10. The catheter body 12 is formed of a flexible polymeric material such as nylon (Pebax ™) manufactured by Atochimie, Cour be Voie, Hauts Ve-Sine, France. The flexible catheter body 12 is preferably in the form of an elongated tube having one or more lights extending longitudinally therethrough.

Referring now to fig. 2, the catheter body 12 has a light 18. Extending longitudinally through the light 18 of the catheter body 12 is an elongated ultrasonic transmission element 30 having a proximal end that can be detachably connected to the ultrasonic transducer 22 so that the ultrasonic energy will pass through the ultrasonic transmission element 30. As such, when the on-off switch 26 operated with the foot operatively connected to the ultrasonic transducer 22 is pressed, the ultrasonic energy will pass through the ultrasonic transmission element 30 to the distal end 16 of the catheter body 12. More particularly, the ultrasonic transmission element 30 serves to transmit the ultrasonic energy from the proximal connector assembly 20 to a distal head 34 mounted at the distal end 16 of the catheter body 12.

The distal head 34 has a substantially rigid element fixed to the distal end 16 of the catheter body 12. In the embodiment shown, the distal head 34 has a generally rounded configuration and has a proximal portion 34b whose outer diameter is slightly smaller than the outer diameter of the distal part 34a of the distal head 34, to define an annular projection 38 to which a distal end 42 of a loop 40 is attached. The proximal end 44 of the loop 40 is attached to the open distal end 46 of the catheter body 12 so that the proximal part 34b is not housed within the catheter body 12 but is separated therefrom. Preferably, the outer diameter of the loop 40 is approximately the same as the outer diameter of the catheter body 12 and the distal portion 34a, thereby forming a generally smooth outer surface at the junction of the distal head 34, the loop 40 and the body of catheter 12, as shown in fig. two.

The connection of the loop 40 to the distal head 34 and the catheter body 12 can be carried out by any suitable way. One way is through the use of an adhesive that is applied to the contact surfaces to be joined. The adhesive may comprise any suitable adhesive, such as cyanoacrylate (e.g., Loctite ™ Corp., Ontario, Canada or Aron Alpha ™, Borden, Inc., Columbus, Ohio) or polyurethane (e.g., Dymax ™, Dymax Engineering Adhesive, Torrington, Connecticut). As an alternative to the use of adhesives, various mechanical or friction connections, such as screw threads, tabs or other surface modifications formed on a surface, with grooves, seals or corresponding surface modifications formed on the contact surface that can be used can also be used. will join

In addition, a guide wire tube 80 defining a guide wire light extends through the light 18, the spiral 40 and a perforation 82 formed through the distal head 34. The guide wire tube 80 can adhere or join in a location 84 to the perforation 82 according to one of the bonding or adhesion procedures described above. The guide wire tube 80 may extend along the length of the catheter body 12 if the catheter device 10 is a "wire" catheter device. If the catheter device 10 is a "monorail" catheter device, as shown in fig. 1, the guide wire tube 80 ends in an opening 86 of adjacent but slightly proximal guide wire 16 of the distal end 16 of the catheter body 12, in which the guide wire 28 exits the catheter body 12 (as is shown in fig. 1).

The distal head 34 may be formed of any suitable rigid material, such as metal or plastic. The distal head 34 is preferably formed of radiodense material so that it is easily discernible by radiographic means. Accordingly, the distal head 34 may preferably be formed of metal or, alternatively, may be formed of plastic, ceramic, glass or rubber materials, optionally having one or more radiodense markers attached thereto or formed therein. For example, the distal head 34 can be molded of plastic, such as acrylonitrile-butadiene-styrene (ABS) and one or more strip (s) of sheet metal or other radiopaque markers can be attached to such a distal head 34 of plastic for confer sufficient radiodensity to allow the distal head 34 to be easily located by radiographic means. Additionally, in embodiments in which the distal head 34 is formed of molded plastic or other non-metallic material, a number of radiodense charges, such as barium sulfate (BaSO4) or bismuth powder may be disposed within the plastic or other material. non-metallic of which the distal head 34 is formed to confer improved radiodensity thereto.

The ultrasonic transmission element 30 extends through the light 18 and the spiral 40, and is inserted into a perforation 62 extending longitudinally into the proximal part 34b of the distal head 34. The distal end of the ultrasonic transmission element 30 is held firmly within the perforation 62 by friction engagement thereof to the surrounding material of the distal head 34, or by other mechanical or chemical fastening means such as, but not limited to a, welded parts, adhesive, soft welding and crimping. Firm fixation of the ultrasonic transmission element 30 to the distal head 34 serves to facilitate the direct transmission of the quanta of the ultrasonic energy that passes through the ultrasonic transmission element 30 to the distal head 34. As a result, it is made that the distal head 34 and the distal end 16 of the

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Catheter device 10 is subjected to ultrasonic vibration according to the combined quanta of the ultrasonic energy that is being transmitted through the ultrasonic transmission element 30.

The loop 40 can be an individual loop, a braid, a multi-lead loop, a backspray, a rounded wire loop, a flat wire loop or any combination thereof. The loop 40 is preferably elastic and is composed of a material that has a high elongation to adapt to the configuration of the distal end 16 and to vibrate with the distal head 34 after the application of ultrasound energy. The loop 40 may be included within a polymeric jacket or coating, such as but not limited to PTFE, polyurethane, polyamide or nylon. The length of the loop 40 can range between 0.1 and 150 cm. Therefore, loop 40 provides several benefits. First, the loop 40 provides an elastic joint of the distal head 34 to the catheter body 12. Secondly, the loop 40 allows the distal head 34 to freely vibrate independently of the catheter body 12. Third, the loop 40 provides an additional connection between the catheter body 12 and the distal head 34 since the loop 40 will hold the distal head 34 to the catheter device 10 in case the ultrasonic transmission element 30 is broken or fractured.

In the preferred embodiment, the ultrasonic transmission element 30 may be formed of any material that can effectively transmit the ultrasonic energy from the ultrasonic transducer 22 to the distal head 34, including but not necessarily limited to metal, plastic, hard rubber, ceramics, fiber optics, glass, polymers and / or composite materials thereof. According to one aspect of the description, the whole

or a part of the ultrasonic transmission element 30 may be formed of one or more materials showing superelasticity. Such materials should preferably show systematic super elasticity within the range of temperatures normally found by the ultrasonic transmission element 30 during operation of the catheter device 10. Specifically, all or part of the ultrasonic transmission element 30 may be formed of one or more metal alloys known as "shape memory alloys."

Examples of superelastic metal alloys that can be used to form the ultrasonic transmission element 30 of the present description are described in detail in US Patent Nos. 4,665,906 (Jervis); 4,565,589 (Harrison); 4,505,767 (Quin); and 4,337,090 (Harrison). Reference is expressly made to the descriptions of US Patents Nos. 4,665,906; 4,565,589; 4,505,767; and 4,337,090 as they describe the compositions, properties, chemical reactions and behavior of specific metal alloys that are super elastic within the temperature range in which the ultrasonic transmission element 30 of the present description operates, each and every one of which can be used of the superelastic metal alloys to form the superelastic ultrasound transmission element 30.

In particular, the present description provides an ultrasonic transmission element 30, all or part of which may be composed of a superelastic metal alloy having the following physical properties:

<dl><dt>PROPERTY </dt><dd>UNITY VALUE </dd></dl>

<dl><dt>Nickel </dt><dd>Atomic weight Min. 50.50 - Max. 51.50</dd></dl>

<dl><dt>Weight percent </dt><dd>Min. 55.50 - Max. 56.07</dd></dl>

<dl><dt>Titanium </dt><dd>% Rest </dd></dl>

<dl><dt>Total gas content (O, H, N) </dt><dd>% 0.15 Max </dd></dl>

<dl><dt>Carbon content </dt><dd>% 0.010 Max. </dd></dl>

<dl><dt>Maximum tensile strength </dt><dd>GPa (PSI) 1.5 (220K) </dd></dl>

<dl><dt>Elongation </dt><dd> % 10-16 </dd></dl>

<dl><dt>Melting point </dt><dd>Celsius 1300 - 1350 </dd></dl>

<dl><dt>Density </dt><dd>g / cm3 6.5 </dd></dl>

This alloy provides an ultrasonic transmission element 30 that experiences minimal attenuation of ultrasound energy, and which has the ability to navigate through the complex curves of the tortuous vessels without experiencing any permanent deformation that would otherwise result in transmission losses

Referring now to fig. 1, the proximal connector assembly 20 of the catheter device 10 has a Y 320 connector. The front part of the Y connector 320 is connected to the proximal end 14 of the catheter body 12. The proximal end of the rear part of the proximal connector assembly 20 is attached to a sonic connector assembly 66 that is configured to effect operative and detachable connection of the proximal end of the ultrasonic transmission element 30 to the protrusion of the ultrasonic transducer 22. The sonic connector apparatus or assembly is preferably configured and constructed to allow ultrasound energy to pass through the ultrasonic transmission element 30 with a minimum side-to-side movement of the ultrasonic transmission element 30 while at the same time vibration or longitudinal forward / backward movement of the ultrasonic transmission element 30 is allowed. Next,

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describes a more detailed description of the sonic connector assembly 66 and the operative separable connection of the ultrasonic transmission element 30 to the ultrasonic transducer 22.

In the ultrasonic system according to the present description, an injection pump 68 or IV bag is connected, via an infusion tube 70, to an infusion hole or side arm 72 of the Y-connector 320. The injection pump 68 It is used to infuse cooling fluid (e.g., 0.9% NaCl solution) into and / or through the catheter device 10, and more particularly into the lumen 18 of the catheter body 12. A flow of this type of refrigerant fluid can be used to prevent overheating of the ultrasonic transmission element 30 that extends longitudinally through the light 18. Due to the desire to infuse refrigerant fluid into the catheter body 12, at least one fluid outlet flow channel 74 extends longitudinally through the distal head 34 to allow the refrigerant fluid to flow from the light 18 out of the distal end 16 of the catheter body 12. See arrows 94 in fig. two. Such flow of the refrigerant fluid through the light 18 serves to bathe the outer surface of the ultrasonic transmission element 30, thereby providing a temperature balance between the refrigerant fluid and the ultrasonic transmission element 30. Thus, the temperature and / or flow rate of the refrigerant fluid can be adjusted to provide cooling and / or other suitable temperature control of the ultrasonic transmission element 30.

In addition to the above, the injection pump 68 can be used to infuse a radiographic contrast medium into the catheter device 10 for imaging purposes. Examples of iodinated radiographic contrast media that can be selectively infused into the catheter device 10 through the injection pump 68 are commercially available as Angiovist 370 from Berlex Labs, Wayne, NJ and Hexabrix from Malinkrodt, St. Louis, MO .

Although the catheter device 10 in fig. 1 is illustrated as a "monorail" catheter device, the catheter device 10 can be provided as a "wire" catheter device without departing from the scope of the present invention. The structural and operational principles of the guide wire "by thread" and "monorail" techniques are well known to those skilled in the art and are not discussed further herein.

The catheter body 12 illustrated in fig. 2 is deployed with the use of a guide wire as a catheter device either "monorail" or "by thread". On the other hand, the catheter body 12 can be deployed without the use of a guidewire, as illustrated in fig. 3, where the catheter body 12x and its distal end 16x are essentially the same as the catheter body 12 and its distal end 16, except that the channel 74, the guide wire tube 80 and the perforation 82 are omitted from the distal head 34x The turns 40x and the ultrasonic transmission element 30x can be the same as the turns 40 and the ultrasonic transmission element 30 in fig. 2. Fig. 3 further illustrates the supply of a deflection wire 88 that extends from the distal head 34x through the light 18x ​​and exits the catheter body 12x through an outlet opening adjacent to the proximal end 14 of the catheter body 12x (see Fig. 1). The deflection wire 88 may be rounded or flat, and may be composed of a flexible and resistant material such as stainless steel or nylon. The deflection wire 88 has a distal end that is attached to the distal head 34x by adhesion, welding, fusion and similar mechanisms, and a proximal end that is connected to a stretching handle 90 provided at the proximal end of the wire 88. When the handle 90 is pulled, the deflection thread 88 will be stretched, thereby causing the distal end 16x to deviate, as shown in fig. Four. When the pulling movement on the handle 90 is released, the thread 88 will relax and return to its normally straight orientation.

It is also possible to provide a 16x distal end of deflection by forming the distal end 16 or 16x of the catheter body 12 or 12x. The conformation of the distal end 16 or 16x at predetermined angles with respect to the catheter body 12 or 12x provides the same function as deflecting the distal end 16x. According to the present description, the conformation of the distal end 16 or 16x can be carried out by radiofrequency, steam or other heat generated procedures. It is important that the previous conformation or conformation of the distal end 16

or 16x does not induce stress or damage to the 30 or 30x ultrasonic transmission element. The conformation of the distal end 16 or 16x can be performed before the actual medical procedure or can be performed by the manufacturer or the physician using conformation techniques that are well known in the art. The shaped 12 or 12x catheter body can then be reshaped as desired using the same procedures.

The present invention further provides a sonic connector assembly 66 that effectively connects the ultrasonic transmission element 30 to the transducer 22 so as to reduce the amplification of the sonic stage and provides a smooth connection transition of the transmission element 30, thereby reducing mode the tension and fatigue experienced by the transmission element 30. The sonic connector assembly 66 includes a sonic connector that functions to grasp or otherwise retain the proximal end of the ultrasonic transmission element 30, and which can be detachably connected to the transducer 22. In other words, the sonic connector serves as connecting element that couples the ultrasonic transmission element 30 to the transducer 22. The present invention provides several different embodiments of sonic connectors that can be used with the sonic connector assembly 66. Each of these sonic connectors functions to detachably connect an ultrasonic catheter to a transducer 22 so that movement is minimized transverse in the connection zone while maintaining the longitudinal propagation of ultrasonic energy. With respect to this, longitudinal vibrations are desirable, while transverse vibrations can cause breakage in the

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ultrasonic transmission element 30. Since the greatest amount of transverse movement occurs in the connection zone between the ultrasonic transmission element 30 and the transducer 22, the elimination of transverse movements in the connection zone between the ultrasonic transmission element 30 and the transducer 22 It is crucial to protect the integrity of the ultrasonic transmission element 30 and minimize the possibility of rupture of the ultrasonic transmission element 30.

In an example that does not fall under the scope according to claim 1 illustrated in fig. 5, the sonic connector assembly 66 has a sonic connector 200 housed within the proximal bore 300 of a puller housing

302 Sonic connector 200 is enlarged in fig. 6 for clarity. The proximal perforation 300 in the handle housing 302 has a rear section 301 having a proximal opening in which a protrusion of the transducer (not shown) can be inserted to engage the sonic connector 200. An enlarged perforation 322 is provided at the distal end of the handle housing 302, communicating the enlarged bore 322 with a channel 310. The structure and characteristics of the puller housing and the transducer boss are well known in the art and are not described in greater detail herein. For example, the puller housing and transducer protrusion may be the same as those illustrated in US Patent No. 5,989,208 issued to Nita, to whose full description reference is made.

The sonic connector 200 has a central part 210 that has a vertical through hole 212 that houses a locking pin 306. The locking pin 306 is inserted through an opening 308 in the handle housing 302 and is housed inside the hole 212 through to retain the sonic connector 200 in a predetermined position within the proximal bore 300 of the handle housing 302, as best illustrated in fig. 12 of US Patent No. 5,989,208. The sonic connector 200 further includes a front shaft 218 that extends distally from the central part 210. The sonic connector 200 also has a threaded rod 226 that extends proximally from the central part 210 to allow the distal end of the projection of the The transducer is screwed in a threaded manner and is detachably connected to the sonic connector 200.

The distal end of the front axle 218 has a perforation 220 that terminates before the central part 210. The proximal end of the ultrasonic transmission element 30 extends through the channel 310 in the handle housing 302 and through the perforation 220, and is sized to fit perfectly within the perforation 220. The proximal end of the ultrasonic transmission element 30 is held within the internal perforation 220 by welding, adhesion, crimping, soft welding or other conventional joining mechanisms. As a non-limiting example, the proximal end of the ultrasonic transmission element 30 is crimped on the front axle 218 at location A.

An intermediate element 224 is seated in the enlarged bore 322 and has a perforation that houses (i.e. circumferentially surrounds) the ultrasonic transmission element 30. In other words, the intermediate element 224 is positioned between the ultrasonic transmission element 30 and the enlarged perforation 322. The intermediate element 224 is preferably composed of an elastic material and non-limiting examples include a polymer or rubber. The intermediate element 224 functions to absorb transverse micromovements, thereby minimizing unwanted transverse vibrations.

The proximal end of the Y-connector 320 can be threadedly engaged in the opening of the enlarged perforation 322. Thus, the intermediate element 224 is separated from the location A of crimping a distance of approximately a quarter of a wavelength.

Fig. 7 illustrates another example of a sonic connector 200b that is not within the scope of claim 1 that is similar to sonic connector 200 in fig. 5. As a result, the same numbers are used to designate the same elements in both figs. 5 and 7, except that the same element in fig. 7 includes a "b" in the designation. The sonic connector 200b has a separate tubular element 234 that is separated from the most distal end of the front shaft 218b. The tubular element 234 has a perforation that retains an intermediate element 224b, which in turn surrounds a part of the ultrasonic transmission element 30. Thus, the intermediate element 224b is now provided within a tubular element 234 as opposed to being provided in the handle housing 302 (as in fig. 5). The tubular element 234 can be crimped into the ultrasonic transmission element 30. Thus, there are two connection locations A and B in fig. 7. The crimping location A implies a crimping of the front shaft 218b and the ultrasonic transmission element 30. The crimping location B implies a crimping of the tubular element 234, the intermediate element 224b and the ultrasonic transmission element 30. In this way, these two connection locations actually provide two separate connection locations, one location (ie, B) being separated from the actual sonic connector 200b and acting as a transverse absorption element.

The sonic connector is normally attached to the transducer at the highest displacement point of the transducer, which is in connection with the sonic connector. Studies have shown that an area in which the ultrasonic transmission element 30 experiences a large amount of voltage is approximately a quarter of the wavelength of the connection with the sonic connector. Therefore, the embodiment in fig. 7 provides a transverse absorption element (i.e. 224b) that is placed at a location along the ultrasonic transmission element 30 that is approximately a quarter of a wavelength from the connection with the

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sonic connector The configuration in fig. 7 eliminates a greater amount of transverse energy at the proximal end of the ultrasonic transmission element 30, thereby minimizing the possible breakage of the ultrasonic transmission element 30. In addition, reducing the transverse movements that propagate towards the distal end of the catheter 10 will result in the generation of less heat, so that an ultrasonic transmission element 30 with a smaller cross-sectional area can be used. This will in turn result in a more flexible catheter 10 that allows the catheter 10 to execute a continuous wave mode (since pulsed emission is a method of reducing heat). The combined use of a continuous wave and pulsed emission mode of operation would allow ultrasound ablation of a greater variety of tissues (eg, soft, hard, fibrous).

The intermediate elements 224, 224b function as absorption elements that minimize unwanted transverse vibrations. To be effective in minimizing transverse vibrations, it is necessary that the absorption element sits firmly around the ultrasonic transmission element 30 to affect the movements or vibrations of transverse micromovements experienced by the ultrasonic transmission element 30. This seat, adjustment or firm grip is generally carried out by creating additional force or by pressing the absorption element against the ultrasonic transmission element 30, which can be done using one of two procedures. In a first procedure, the absorption element is pressed longitudinally. Unfortunately, this longitudinal force can deform the absorption element and can create a non-uniform grip that could in turn provide an inconsistent grip around the ultrasonic transmission element 30. Fortunately, this inconsistency can be overcome by providing a plurality of o-rings around the ultrasonic transmission element 30, as described below in relation to fig. 8. A second procedure uses a perpendicular (i.e., transverse) force to compress the absorption element around the ultrasonic transmission element 30 and the crimping techniques described in figs. 5 and 7 in this document are examples of this second procedure.

Fig. 8 illustrates how sonic connector 200 shown in fig. 6 with a slightly different handle housing to overcome the inconsistent grip around the ultrasonic transmission element 30 provided by a longitudinal grip force. The handle housing 302c in fig. 8 is similar to the handle housing 302 in fig. 5, so the same numbers are used to designate the same elements in both figs. 5 and 8, except that the same element in fig. 8 includes a "c" in the designation. In the puller housing 302c, the perforation 300c is provided as an individual perforation, without the channel 310 or the extended perforation 322. The ultrasonic transmission element 30 extends through the Y-connector 320 and into the perforation 300c, and a plurality of o-rings 330 are provided around the ultrasonic transmission element 30 within the perforation 300c. Thus, the O-rings 330 function as the absorption elements 224 and 224b, and sit firmly around the ultrasonic transmission element 30 adjacent to the connection area of ​​the ultrasonic transmission element 30 and the transducer 22 to affect the movements or vibrations of transverse micromovements experienced by the ultrasonic transmission element 30 in this location where the transverse movement is the greatest. In addition, the length of the plurality of o-rings combined 330 extends through a larger proximal area of ​​the ultrasonic transmission element 30 (when compared to the length of the absorption elements 224, 224b), so that the embodiment of fig. 8 is best suited for use in applications where the transverse movements are greater. In contrast, the embodiments in figs. 5 and 7 can best be adapted for use in applications where the transverse movements are smaller.

Fig. 9 illustrates a modification that can be made to the handle housing 302c in fig. 8. In the handle housing 302c in fig. 9, the O-rings 330 are replaced by a single absorption element 332 contained within the perforation 300c and around the ultrasonic transmission element 30. The absorption element 332 may have the same distinctive features, characteristics and materials as the intermediate elements 224 and 224b described above. The length of the absorption element 332 can be provided such that the absorption element 332 covers the distance from the distal end 334 of the absorption element 332 to the sonic connector 200, which is approximately a quarter of a wavelength. The embodiment in fig. 9 shares the same benefits as the embodiment in fig. 8.

Fig. 10 illustrates another modification that can be made to the handle housings 302c in figs. 8 and 9. In particular, a combination of o-rings 330d and absorption elements 332d may be contained within the perforation 300c and around the ultrasonic transmission element 30. In fig. 10, a group of o-rings 330d can be placed between two separate absorption elements 332d, although different arrangements of o-rings 330d and absorption elements 332d can also be used. The o-rings 330d and the absorption elements 332d may be the same as the o-rings 330 and the absorption element 332 described above. Again, the embodiment in fig. 10 shares the same benefits as the embodiments in figs. 8 and 9.

Fig. 11 illustrates modifications that do not fall within the scope of claim 1 that can be made to the puller housing 302 in fig. 5, which borrow the principles illustrated in figs. 8-10. The handle housing 302 in fig. 11 is identical to the handle housing 302 in fig. 5, whereby the same numbers are used to designate the same elements of the handle housing 302 in figs. 5 and 11. In fig. 11, one

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first plurality of o-rings 330e may be contained within the perforation 300 and around the ultrasonic transmission element 30, and a second plurality of o-rings 330f may be contained within the enlarged perforation 322 and around the ultrasonic transmission element 30 . In addition, an intermediate element 224e may be contained within the borehole 338 of the Y-connector 320 (at the connection location between the enlarged bore 322 and the proximal end of the Y-connector 320) and around the ultrasonic transmission element 30. The o-rings 330e, 330f and the intermediate element 224e can be the same as the o-rings 330 and the intermediate element 224 described above. The distance from intermediate element 224e to sonic connector 200 may be approximately a quarter of a wavelength.

The provision of sonic connectors and puller housings illustrated in figs. 5 and 7-11 is so effective in reducing stresses in the ultrasonic transmission element 30 that facilitate the use of a 16x distal end that can be deflected as described hereinbefore. The previously known ultrasound catheters have not been able to enjoy the luxury of a distal end that can be deflected because any curvature at the distal end of the ultrasonic transmission element 30 would cause the ultrasound transmission element 30 to also be curved thereby increasing the stresses already experienced by the ultrasonic transmission element 30, opposing resistance to the longitudinal propagation of ultrasonic energy and creating an additional heat source, all of which would increase the possibility of rupture of the ultrasonic transmission element 30. Therefore, the implementation of the sonic connectors illustrated in figs. 5 and 7-11 allows the distal end of the ultrasonic transmission element 30 to bend without experiencing many of these disadvantages.

The present description further provides reverse irrigation to remove particles that have undergone ablation during the ultrasound procedure. Referring to fig. 2, irrigation fluid may be injected through a guide catheter 240 (and along the outer surface of the catheter body 12) as shown by arrows 242. The irrigation fluid will travel to the distal head 34 of the catheter 10 and will carry the particles through the channel 74 in an inverse direction (i.e., from distal to proximal) and through the light

18. The irrigation fluid and particles will travel proximally along the light 18 to the infusion tube 70, and will be collected in a bottle or container 69 that can be connected to the infusion tube 70. During this operation, the Injection pump 68 can serve as a negative pressure pump.

Even as an additional alternative, the particles can be removed by applying vacuum to remove the particles through the light of the guide wire tube 80. For example, in one embodiment of a "wire" catheter, the particles can be removed through the light of the guide wire tube 80 using a pump or syringe.

Although the above description refers to particular embodiments of the present invention, it will be understood that many modifications can be made without departing from the scope thereof. It is intended that the appended claims cover such modifications as they will fall within the true scope of the present invention.