In-stent restenosis detection device

• US 6,729,336 B2
• Filed: 03/28/2002
• Issued: 05/04/2004
• Est. Priority Date: 11/27/2001
• Status: Expired due to Fees

• Current Assignee: Pearl Technology Holdings LLC
• Original Assignee: Pearl Technology Holdings LLC
• Inventors: Esch, Victor C., Hares, Jonathan, Collins, Gilbert W., Kilkenny, Joseph D., Da Silva, Luiz B., Rubenchik, Alexander M., Weber, Paul J.
• Primary Examiner(s): Lacyk, John P.
• Application Number:
  US10/109,150
• Publication Number:
  US 20030100815A1
• Time in Patent Office: 768 Days
• Field of Search: 600/9, 600/454, 600/459, 600/500, 600/504, 600/505, 128/897-99, 607/60, 607/61, 607/62, 607/65
• US Class Current: 128/897
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/05 Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves impedance plethysmography A61B5/0295; measuring movement of the entire body or parts thereof A61B5/11; detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof A61B5/24
• CPC Class Codes: A61B 5/0507 using microwaves or terahertz waves
• CPC Class Codes: A61B 8/08 Detecting organic movements or changes, e.g. tumours, cysts, swellings A61B8/02 - A61B8/06 take precedence
• CPC Class Codes: A61N 1/40 Applying electric fields by inductive or capacitive coupling microwave apparatus A61N5/00; Applying radio-frequency signals

Abstract

A medical device is described that can be used to detect in stent restenosis. This invention consists of a stent of current or modified technology, an electromagnetic wave transmitter to excite the stent and an acoustic sensor to detect stent acoustic oscillations.

Claims

1. An apparatus, comprising:

a stent;

means for exciting said stent with an electromagnetic (EM) waves to produce an acoustic waves; and

means for detecting said acoustic waves.

2. The apparatus of claim 1, further comprising means for analyzing said acoustic waves to determine if stent restenosis has occurred.

3. The apparatus of claim 1, wherein said means for exciting said stent comprises an EM wave transmitter capable of transmitting waves within a frequency range from 10 MHz to 10 GHz to excite acoustic oscillations in said stent.

4. The apparatus of claim 1, wherein said means for detecting said acoustic waves comprises an ultrasound detector.

5. The apparatus of claim 1, further comprising means for modulating said EM waves.

6. The apparatus of claim 2, wherein said means for analyzing said acoustic waves comprises a computer readable medium including software with an algorithm that determines if a change in acoustic spectrum has occurred and if so, uses said change to identify restenosis.

7. The apparatus of claim 3, further comprising EM wave transmitter includes a transmitter selected from the group consisting of a pair of coils, a single coil, a fractal antenna, an open dipole transmitter and a patch antenna.

8. The apparatus of claim 5, wherein said means for modulating said EM waves produces a modulation selected from the group consisting of a sinusoidal modulation and a square wave modulation.

9. The apparatus of claim 5, wherein said EM waves are modulated at a frequency selected to effectively couple energy into said stent.

10. The apparatus of claim 5, wherein said EM waves are modulated at a frequency selected to be near the stent acoustic resonance frequency.

11. The apparatus of claim 5, wherein said EM waves are modulated at a frequency within a range from about 100 kHz to about 2 MHz).

12. The apparatus of claim 4, further comprising an acoustic lens for directing acoustic waves onto said acoustic detector.

14. The apparatus of claim 1, wherein said stent comprises an electrically conductive portion.

15. The apparatus of claim 1, wherein said stent has an imprinted resonance circuit tuned to a RF frequency.

16. The apparatus of claim 1, wherein said algorithm comprises a peak detection algorithm.

13. The apparatus of claim, wherein said means for detecting said acoustic waves includes a lock-in amplifier.

17. A method for detecting in-stent restenosis, comprising:

exciting a stent with electromagnetic (EM) waves to produce an acoustic waves; and

detecting said acoustic waves.

18. The method of claim 17, further comprising analyzing said acoustic waves to determine if stent restenosis has occurred.

19. The method of claim 17, wherein the step of exciting said stent comprises is carried out with EM waves within a frequency range from 10 MHz to 10 GHz.

20. The method of claim 17, further comprising modulating said EM waves.

21. The method of claim 18, wherein the step of analyzing said acoustic waves comprises determining if a change in acoustic spectrum has occurred to identify restenosis.

22. The method of claim 20, wherein the step of modulating said EM waves is carried out with a modulation selected from the group consisting of a sinusoidal modulation and a square wave modulation.

23. The method of claim 20, wherein said EM waves are modulated at a frequency selected to effectively couple energy into said stent.

24. The method of claim 20, wherein said EM waves are modulated at a frequency selected to be near the stent acoustic resonance frequency.

25. The method of claim 20, wherein said EM waves are modulated at a frequency within a range from about 100 kHz to about 2 MHz).

26. The method of claim 18, wherein the step of analyzing said acoustic waves is carried out with a peak detection algorithm.