Intravascular ultrasonic angioplasty probe

• US 5,069,664 A
• Filed: 01/25/1990
• Issued: 12/03/1991
• Est. Priority Date: 01/25/1990
• Status: Expired due to Term

• Current Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Original Assignee: InterTherapy, Inc. (Boston Scientific Corporation)
• Inventors: Guess, Joe F., Zalesky, Paul J.
• Primary Examiner(s): Apley, Richard J.
• Assistant Examiner(s): Thomas, L.
• Application Number:
  US07/469,770
• Time in Patent Office: 677 Days
• Field of Search: 128/24 R, 128/660.03, 128/662.06, 604/22
• US Class Current: 604/22
• CPC Class Codes: A61B 17/2202 the ultrasound transducer being inside patient's body at the distal end of the catheter
• CPC Class Codes: A61B 2217/005 with suction drainage system
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers

Abstract

A probe for ultrasonically removing unwanted biological material, for example, from a vessel in a patient'"'"'s cardiovascular system, includes a catheter assembly having distal and proximal catheter sections, each defining a respective lumen. A subassembly is connected to and between these catheter sections and houses piezoceramic transducer elements which are adapted to vibrate at ultrasonic frequencies. An elongate flexible working element (e.g., one or more wire elements) is housed within the distal catheter section and projects beyond that section'"'"'s distal end so as to be adapted to contact unwanted biological material. The proximal end of the working element is coupled to the transducer elements via ultrasonic coupling structures so as to responsively vibrate at ultrasonic frequencies. The subassembly also defines an aspiration channel which fluid-connects the lumens of the proximal and distal catheter sections so that unwanted biological material removed by the ultrasonically vibrated working element may be aspirated to a patient-external specimen collection site.

Claims

1. An probe for ultrasonically removing unwanted biological tissue comprising an elongate probe assembly having proximal and distal end portions, and a transducer subassembly located near said distal end portion of said probe assembly, wherein said transducer subassembly includes:

transducer means having a predetermined length dimension and adapted to vibrate at ultrasonic frequencies in response to electrical driving signals;

elongate ultrasonic horn means positioned laterally adjacent to said transducer means and aligned substantially parallel to said length dimension thereof;

coupling means rigidly coupling the proximal ends of said transducer means and said ultrasonic horn means one to another so as to allow said vibratory displacements of said transducer means to be transferred to said horn means; and

flexible wire means operatively connected to and distally extending from said horn means so that said vibratory displacements of said horn means are responsively transferred to said wire means, wherein said wire means includes a terminal end portion adapted to contact said unwanted biological tissue and to remove the same by means of said responsive vibratory displacements thereof.

4. A probe as in any one of claim 1-3, wherein said transducer means comprises diametrically opposed sets piezoelectric transducer elements.

2. A probe assembly for removing unwanted biological tissue comprising an elongate probe assembly which includes a distally located transducer subassembly, said transducer subassembly including:

ultrasonic transducer means having proximal and distal ends, said transducer means undergoing vibratory displacements at ultrasonic frequencies in response to receiving an electrical stimulus;

ultrasonic horn means having proximal and distal ends and positioned laterally adjacent and parallel to said transducer means; and

coupling means, which is located essentially at a node position whereby minimum vibratory displacements occur, for rigidly coupling said proximal end of said transducer means to said proximal end of said horn means so that said proximal ends of said transducer means and said horn means are likewise located essentially at said node position;

wherein

said distal ends of said transducer means and said horn means are unconnected to one another and are each located at an antinode portion whereby maximum vibratory displacements occur, and wherein

said vibratory displacement of said horn means distal end is out of phase with said vibratory displacement of said transducer means distal end such that when one of said distal ends is displaced to a maximum extent in one direction, the other of said distal ends is displaced to a maximum extent in an opposite direction; and

wherein

said probe assembly further includes working element means operatively coupled to said horn means distal end for responsive vibratory displacements therewith.

3. A probe for ultrasonically removing unwanted biological material from a vessel in a patient'"'"'s vascular system comprising a catheter assembly which is sized and configured to be inserted within the vessel of a patient'"'"'s vascular system containing the unwanted biological material, said catheter assembly including:

(i) distal and proximal extending catheter sections each defining a respective lumen;

(ii) a subassembly connected to and between said distally and proximally extending catheter sections;

(iii) an elongate working element housed within said distal catheter section and having a proximal end located adjacent said subassembly and a distal end which is exposed beyond a terminal end of said distal catheter section;

(iv) said subassembly including (a) transducer means having a pair of transducer elements adapted which are laterally separated relative to a longitudinal direction of the catheter assembly so as to establish a longitudinal space therebetween, said pair of transducer elements adapted to vibrate at ultrasonic frequencies in response to electrical driving signals, (b) means for coupling said ultrasonic vibration of said transducer means to said working element so that said working element responsively vibrates at ultrasonic frequencies, said means for coupling including an ultrasonic horn disposed in said space between said pair of transducer elements and oriented substantially parallel thereto, and (c) means establishing an aspiration channel longitudinally through said subassembly so as to fluid-connect the lumens of said proximally and distally extending catheter sections.

5. A probe as in claim 3, wherein said working element includes at least one elongate flexible wire element.

6. A probe as in claim 3, wherein said coupling means includes an elongate horn element.

7. A probe as in claim 6, wherein said coupling means includes acoustic coupling means operatively connected to said horn element for acoustically coupling said horn element and said transducer means.

8. A probe as in claim 7, wherein said horn element has one end rigidly fixed to said coupling means and another end opposite to said one end, said horn element being unsupported along its length between said one and another ends.

9. A probe as in claim 7, wherein said horn element has one end rigidly fixed to said coupling means and another end opposite to said one end, and including means for supporting an axial length of said horn element between said one and another ends thereof.

10. A medical probe assembly for removing selected tissue, comprising:

a catheter defining a catheter lumen;

transducer means positioned at a distal end portion of said catheter and oriented along a length-wise dimension of said catheter, said transducer being capable of vibratory movements at ultrasonic frequencies in response to receiving an electrical stimulus;

a flexible working element extending distally relative to said transducer means; and

coupling means for transferring said ultrasonic vibratory movements of said transducer means to said flexible working element;

wherein said coupling means includes

(i) an elongate horn element positioned laterally adjacent and parallel to said transducer means; and

(ii) acoustic coupling means for acoustically coupling said horn element and said transducer means to transfer vibratory movements of said transducer means to said horn element.

11. A probe assembly as in claim 10, wherein said horn element has one end rigidly fixed to said coupling means and another unsupported end opposite to said one end.

12. A medical probe assembly for removing selected tissue, comprising:

a catheter defining a catheter lumen;

transducer means having a pair of laterally separated transducer elements positioned at a distal end portion of said catheter and oriented in a lengthwise direction of said catheter, said transducer being capable of vibratory movements at ultrasonic frequencies in reponse to receiving an electrical stimulus;

a flexible working element extending distally relative to said transducer means; and

coupling means for (i) coupling said vibratory movements of said transducer means to said flexible working element, and (ii) amplifying the magnitude of said ultrasonic vibratory movements of said transducer means to produce a relatively greater magnitude of vibratory movement of said flexible working element wherein said coupling means includes,

an elongate horn element positioned laterally adjacent and parallel to said transducer means between said laterally separated transducer elements, and

acoustic coupling means for acoustically coupling said horn element and said transducer means for vibration in a longitudinal direction, wherein

said horn element has an end rigidly fixed to said coupling means and an unsupported end opposite to said fixed end, said horn element being unsupported along its length between said fixed and unsupported ends.

13. A probe assembly as in claim 12, wherein said transducer means includes diametrically opposed sets of transducer elements.

14. An axially elongate medical probe assembly for removing selected tissue, comprising:

a catheter defining a catheter lumen;

transducer means located at a distal portion of said catheter and adapted to vibrate at ultrasonic frequencies in response to receiving an electrical stimulus;

at least one flexible wire working element; and

coupling means for acoustically coupling said transducer means and said working element, said coupling means including acoustic horn means having one end operatively coupled to said transducer means and an opposite end operatively coupled to said working element, wherein

said transducer means including (i) a diametrically opposed, laterally separated set of transducer elements axially oriented relative to said catheter, (ii) an annular rigid disc positioned in axially spaced relation to said coupling means, (iii) said set of transducers being positionally fixed between said coupling means and said rigid disc so as to maintain said lateral separation of said set of transducer elements, and (iv) a horn element having a proximal end operatively coupled to said coupling means and extending distally therefrom so as to be disposed between said laterally separated set of transducer elements.

15. An intravascular probe for removing arterial obstructions, comprising in combination:

an elongate catheter defining a catheter lumen;

said catheter including a distally positioned subassembly adapted to being inserted into a patient'"'"'s vascular system, said subassembly establishing distal (and proximal catheter portions having respective distal and) proximal lumens;

said subassembly including (i) an ultrasonic transducer comprised of diametrically opposed and laterally separated sets of piezoelectric ceramic elements, (ii) means defining at least one channel which fluid-connects said distal and proximal lumens to allow fluid to flow through said subassembly between said laterally separated sets of piezoelectric ceramic elements, and (iii) an ultrasonic horn element positioned between said diametrically opposed and laterally separated sets of piezoelectric ceramic elements;

at least one flexible wire element disposed within said distal lumen and having a terminal end adapted to contact an arterial obstruction; and

means for acoustically coupling said ultrasonic transducer and said at least one flexible wire element so as to transfer ultrasonic vibrations of said transducer to said wire element, whereby said vibrating wire element is adapted to remove arterial obstructions.

16. A probe as in claim 15, wherein said acoustic coupling means further includes an elongate horn element operatively coupled to and positioned between sets of piezoelectric ceramic elements at one end thereof, wherein said flexible wire element is secured to an opposite end thereof.

17. A system for removing intravascular obstructions comprising:

a probe assembly which includes,

(i) distal and proximal catheter portions each defining distal and proximal catheter lumens, respectively;

(ii) a subassembly connected to and between said distal and proximal catheter portions, said subassembly housing a pair of laterally separated ultrasonic transducer elements, said subassembly defining an aspiration channel which fluid-connects said distal and proximal catheter lumens and allows fluid to flow through said subassembly between said pair of laterally separated transducer elements, and a ultrasonic horn element positioned between said pair of laterally separated transducer elements;

(iii) at least one elongate wire element connected to said horn element and extending from said subassembly within said distal catheter portion, said wire element having a proximal end in operative association with said transducer so as to be responsively vibrated ultrasonically by means of said transducer, and a distal end adapted to contact said intravascular obstruction, whereby ultrasonic vibration of said wire element removes at least a portion of said obstruction in contact with said wire element distal end;

said system further comprising,

ultrasonic driver means operatively coupled to said transducer for causing said transducer to vibrate ultrasonically; and

aspiration means in fluid communication with said proximal catheter lumen for aspirating said removed obstruction portion sequentially through said distal catheter lumen, said subassembly via said aspiration channel and said proximal catheter lumen to a patient-external collection site.

18. A system as in claim 17, wherein said piezoceramic transducer comprises diametrically opposed sets of piezoelectric crystal elements positionally fixed within said subassembly.