Ultrasound catheter probe

• US 5,779,644 A
• Filed: 09/11/1996
• Issued: 07/14/1998
• Est. Priority Date: 02/01/1993
• Status: Expired due to Term

• Current Assignee: Volcano Corporation (Koninklijke Philips N.V.)
• Original Assignee: Endosonics Corporation (JOMED NV)
• Inventors: Eberle, Michael J., Kiepen, Horst F., Rizzuti, Gary P.
• Primary Examiner(s): JAWORSKI, FRANCIS J
• Application Number:
  US08/712,166
• Time in Patent Office: 671 Days
• Field of Search: 127/660.03, 127/662.06, 29/25.35
• US Class Current: 600/463
• CPC Class Codes: A61B 8/06 Measuring blood flow measuring volume flow in general G01F, e.g. G01F1/66, G01F1/72; measuring speed of fluids in general G01P5/00
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/445 Details of catheter construction
• CPC Class Codes: A61B 8/4483 characterised by features of the ultrasound transducer
• CPC Class Codes: A61B 8/4488 the transducer being a phased array
• CPC Class Codes: A61B 8/4494 characterised by the arrangement of the transducer elements devices for short-range imaging using particular transducer elements arrangements under G01S15/8909; arrangements of transducers in generation of mechanical vibrations of infrasonic, sonic or ultrasonic frequency B06B1/0607
• CPC Class Codes: B06B 1/0633 Cylindrical array
• CPC Class Codes: B06B 1/067 which is used as, or combined with, an impedance matching layer
• CPC Class Codes: B06B 1/0674 and a low impedance backing, e.g. air
• CPC Class Codes: B06B 2201/76 Medical, dental
• CPC Class Codes: G01S 15/892 the array being curvilinear
• CPC Class Codes: G01S 15/8979 Combined Doppler and pulse-echo imaging systems
• CPC Class Codes: G01S 15/8981 Discriminating between fixed and moving objects or between objects moving at different speeds, e.g. wall clutter filter
• CPC Class Codes: G01S 15/899 Combination of imaging systems with ancillary equipment
• CPC Class Codes: G10K 11/004 Mounting transducers, e.g. provided with mechanical moving or orienting device mountings specially adapted to a particular sound-producing device, see the preceding groups G10K1/00 - G10K9/00, e.g. G10K1/26, G10K1/28, G10K9/22; arrangements of sonic watch equipment on submarines B63G8/39; buoys B63B22/00
• CPC Class Codes: G10K 11/008 Arrays of transducers seismic streamers, see G01V1/20
• CPC Class Codes: Y10T 29/42 Piezoelectric device making

Abstract

An ultrasound catheter is disclosed for providing substantially real-time images of small cavities. The ultrasound catheter is characterized by separate and distinct materials for backing the transducers and for carrying the electronics components. The separate materials comprise an electronics carrier meeting the requirements for holding the integrated circuitry of the ultrasound device and a backing material displaying superior characteristics relating to reducing ringing and minimizing the effect of other sources of signal degradation in the transducer assembly. Also, in accordance with the present invention, a technique is described for connecting the conductor lines of the separate transducer assembly and electronics body.

Claims

1. A method of making an ultrasound transducer probe assembly for insertion into a cavity and emitting ultrasonic waves to facilitate construction of a usable image in accordance with detected reflected ultrasonic acoustic waves, said method comprising the steps:

manufacturing a planar sheet comprising a set of transducer elements and a substrate;

re-shaping the planar sheet into a substantially non-planar shape; and

communicatively coupling the set of transducer elements to integrated circuits on the ultrasound transducer probe.

2. The method of claim 1 wherein the step of manufacturing a planar sheet comprises forming a layered structure including a set of conducting electrodes, a transducer material, a continuous layer conducting electrode, and a matching layer.

3. The method of claim 2 wherein the re-shaping step comprises reforming the planar sheet such that the matching layer is located at a convex side of the set of transducer elements.

4. The method of claim 2 wherein the matching layer that is re-formed during said re-shaping step has a thickness of approximately a quarter wavelength of the ultrasound waves emitted by the set of transducer elements.

5. The method of claim 1 further comprising physically isolating each transducer element of the set of transducer elements from other ones of the set of transducer elements.

6. The method of claim 5 wherein the planar sheet comprises a continuous sheet of transducer material and wherein the step of physically isolating each transducer element comprises dicing the continuous sheet of transducer material.

7. The method of claim 1 wherein the set of transducer elements formed during said manufacturing step comprises PZT.

8. The method of claim 1 wherein the planar sheet is re-shaped during the re-shaping step into a cylindrical shape.

9. The method of claim 8 further comprising at least partially filling the cylindrical shape with a backing material.

10. The method of claim 9 wherein the step of at least partially filling the cylindrical shape is performed after the re-shaping step in order to render the cylindrical shape at least partially filled with the backing material.

11. The method of claim 9 further comprising forming an electronics carrier for supporting the integrated circuits, and wherein the backing material has a relatively lower acoustic impedance and a relatively higher loss coefficient than that of the electronics carrier.

12. The method of claim 11 wherein the backing material, added to the ultrasound transducer assembly during the at least partially filling step, comprises an epoxy resin.

13. A method for fabricating an ultrasound transducer probe assembly comprising a flexible substrate, integrated circuitry, and a set of transducer elements for use in providing images of a blood vessel from within a vasculature, the method comprising the steps:

manufacturing a planar sheet comprising the set of transducer elements upon the flexible substrate;

electrically coupling the integrated circuitry to the ultrasound transducer elements via a set of conducting lines; and

re-shaping the planar sheet into a non-planar shape.

14. The method of claim 13 wherein the manufacturing step includes providing a suitable material for the flexible substrate such that when completed, the flexible substrate comprises a matching layer for the ultrasound transducer assembly.

15. The method of claim 13 wherein the step of manufacturing a planar sheet comprises forming a layered structure including a set of conducting electrodes, a transducer material, a continuous layer conducting electrode, and a matching layer.

16. The method of claim 15 wherein the re-shaping step comprises re-forming the planar sheet such that the matching layer is located at a convex side of the set of transducer elements.

17. The method of claim 16 wherein the matching layer that is re-formed during said re-shaping step has a thickness of approximately a quarter wavelength of the ultrasound waves emitted by the set of transducer elements.

18. The method of claim 13 further comprising physically isolating each transducer element of the set of transducer elements from other ones of the set of transducer elements.

19. The method of claim 18 wherein the planar sheet comprises a continuous sheet of transducer material and wherein the step of physically isolating each transducer element comprises dicing the continuous sheet of transducer material.

20. The method of claim 13 wherein the set of transducer elements formed during said manufacturing step comprises PZT.

21. The method of claim 13 wherein the planar sheet is re-shaped during the re-shaping step into a cylindrical shape.

22. The method of claim 21 further comprising at least partially filling the cylindrical shape with a backing material.

23. The method of claim 22 wherein the step of at least partially filling the cylindrical shape is performed after the re-shaping step in order to render the cylindrical shape at least partially filled with the backing material.

24. The method of claim 22 further comprising forming an electronics carrier for supporting the integrated circuits, and wherein the backing material has a relatively lower acoustic impedance and, a relatively higher loss coefficient than that of the electronics carrier.

25. The method of claim 24 wherein the backing material, added to the ultrasound transducer assembly during the at least partially filling step, comprises an epoxy resin.