Ultrasonic detection of restenosis in stents

• US 6,308,715 B1
• Filed: 02/24/2000
• Issued: 10/30/2001
• Est. Priority Date: 03/24/1999
• Status: Expired due to Fees

• Current Assignee: PMD Holdings Corporation (Berkshire Hathaway Incorporated)
• Original Assignee: PMD Holdings Corporation (Berkshire Hathaway Incorporated)
• Inventors: Weissman, Eric M., Spillman, William B. Jr., Dickens, Elmer D. Jr.
• Primary Examiner(s): Lacyk, John P.
• Assistant Examiner(s): MARMOR II, CHARLES ALAN
• Application Number:
  US09/512,183
• Time in Patent Office: 614 Days
• Field of Search: 600/456, 600/454, 600/459, 600/500, 600/504, 600/505, 600/437, 601/2, 735/79, 735/84, 128/897, 128/899, 128/903, 623/1.1, 623/1.3, 623/11, 623/12, 607/60, 607/61, 607/65
• US Class Current: 128/899
• CPC Class Codes: A61B 2560/0219 of externally powered implanted units
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: A61B 5/726 using Wavelet transforms
• CPC Class Codes: A61B 8/0833 involving detecting or locating foreign bodies or organic structures
• 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 8/582 Remote testing of the device
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61F 2250/0001 Means for transferring electromagnetic energy to implants

Abstract

An analyzer apparatus and method is provided for analyzing restenosis associated with a stent implanted within a living body. The apparatus includes an input for receiving ultrasonic data from an ultrasonic imaging apparatus; digital memory for storing the ultrasonic data at least temporarily; a processor for analyzing the ultrasonic data, the processor being configured to analyze the data in accordance with at least one predefined criteria to diagnose a degree of restenosis experienced by the stent; and an output for outputting information indicative of the diagnosis.

Claims

1. An analyzer apparatus for analyzing restenosis associated with a stent implanted within a living body, comprising:

an input for receiving ultrasonic data from an ultrasonic imaging apparatus;

digital memory for storing the ultrasonic data at least temporarily;

a processor for analyzing the ultrasonic data, the processor being configured to analyze the data in accordance with at least one predefined criteria to diagnose a degree of restenosis experienced by the stent; and

an output for outputting information indicative of the diagnosis.

2. The apparatus of claim 1, wherein the processor analyzes the data based on predefined knowledge of a mechanical transfer function of the stent stored in the digital memory.

3. The apparatus of claim 1, wherein the processor analyzes the data by detecting a change in amplitude of the ultrasonic data relative to a predefined criteria.

4. The apparatus of claim 1, wherein the processor analyzes the data by detecting a reduction in resonance of the stent relative to a predefined criteria.

5. The apparatus of claim 1, wherein the processor analyzes the data by detecting a change in transfer function relative to a predefined criteria.

6. The apparatus of claim 1, wherein the processor analyzes the data by calculating an amplitude decay rate.

7. The apparatus of claim 1, further comprising a signature database for prestoring signature data associated with a plurality of different stents.

8. The apparatus of claim 7, wherein the processor analyzes the data based on the signature data stored in the signature database.

9. The apparatus of claim 8, wherein the processor performs pattern matching between the data and the signature data.

10. The apparatus of claim 9, wherein the processor comprises a digital signal processor.

11. The apparatus of claim 1, wherein the input is configured to receive ultrasonic data from an RF output of an ultrasonic imaging apparatus.

12. The apparatus of claim 11, further comprising an interface for providing remote control commands to the ultrasonic imaging apparatus.

13. The apparatus of claim 12, wherein the processor is configured to provide control commands to adjust a position of an ultrasonic beam produced by the ultrasonic imaging apparatus.

14. The apparatus of claim 13, wherein the control commands are provided in accordance with a predefined criteria to irradiate the stent with the ultrasonic beam.

15. A system for analyzing restenosis associated with a stent implanted within a living body, comprising:

an ultrasonic apparatus for non-invasively providing ultrasonic data related to the stent;

digital memory for storing the ultrasonic data at least temporarily;

a processor for analyzing the ultrasonic data, the processor being configured to analyze the data in accordance with at least one predefined criteria to diagnose a degree of restenosis experienced by the stent; and

an output for outputting information indicative of the diagnosis.

16. The system of claim 15, wherein the processor analyzes the data based on predefined knowledge of a mechanical transfer function of the stent stored in the digital memory.

17. The system of claim 15, wherein the processor analyzes the data by detecting a change in amplitude of the ultrasonic data relative to a predefined criteria.

18. The system of claim 15, wherein the processor analyzes the data by detecting a reduction in resonance of the stent relative to a predefined criteria.

19. The system of claim 15, wherein the processor analyzes the data by detecting a change in content relative to a predefined criteria.

20. The system of claim 15, wherein the processor analyzes the data by calculating an amplitude decay rate.

21. The system of claim 15, further comprising a signature database for prestoring signature data associated with a plurality of different stents.

22. The system of claim 21, wherein the processor analyzes the data based on the signature data stored in the signature database.

23. The system of claim 22, wherein the processor performs pattern matching between the data and the signature data.

24. The system of claim 23, wherein the processor comprises a digital signal processor.

25. A computer program for analyzing restenosis associated with a stent implanted within a living body, the computer program being stored on a machine-readable medium and comprising instructions and data for carrying out the following steps:

analyzing ultrasonic data obtained from the stent in accordance with at least one predefined criteria; and

diagnosing a degree of restenosis experienced by the stent based on the analysis of the ultrasonic data.