Noninvasive tissue assessment

• US 20050113691A1
• Filed: 09/07/2004
• Published: 05/26/2005
• Est. Priority Date: 09/05/2003
• Status: Active Grant

• Current Assignee: Rice University
• Original Assignee: Rice University
• Inventors: Liebschner, Michael A. K.
• Granted Patent: US 7,435,232 B2
• Time in Patent Office: Days
• US Class Current: 600/437
• CPC Class Codes: A61B 5/0051 by applying vibrations
• CPC Class Codes: A61B 5/4504 Bones A61B5/4547 takes precedence
• CPC Class Codes: A61B 5/4509 Bone density determination
• CPC Class Codes: A61B 5/4514 Cartilage
• CPC Class Codes: A61B 5/4519 Muscles A61B5/389, A61B5/224 take precedence
• CPC Class Codes: A61B 5/4523 Tendons
• CPC Class Codes: A61B 5/4533 Ligaments
• CPC Class Codes: A61B 9/00 Instruments for examination by percussion; Pleximeters
• CPC Class Codes: Y10S 128/92 Computer assisted medical diagnostics
• CPC Class Codes: Y10S 128/923 by comparison of patient data to other data

Abstract

Methods and apparatus for non-invasively assessing physiological hard of soft tissue of human and other species are described. In a preferred embodiment, tissue is vibrationally stimulated in vivo through a frequency spectrum. The tissue reacts against the stimulus and the reaction is preferably measured and recorded. Based on analytical algorithms or comparisons with previously taken measurements, changes within the tissue can be detected and used for diagnostic purposes. Further embodiments describe the usage of the device and methods for in vivo intra-operative and post-operative implant evaluations and as a therapeutic tool.

Claims

1. A device for tissue quality assessment comprising:

(a) a signal generator capable of generating a signal;

(b) a means for inducing vibration based on the signal from (a) over a frequency range into one or more tissues at a point of origin;

(c) a means for measuring a tissue response at the point of origin in (b);

wherein both (a), (b) and (c) are contained in a single original device.

2. The device according to claim 1 wherein the frequency range is about 20 Hz to about 1.5 MHz.

3. The device according to claim 1 wherein the frequency range is about 20 Hz to about 600 kHz.

4. The device according to claim 1 wherein the frequency range is about 800 Hz to about 1.5 MHz.

5. The device according to claim 1 wherein the means for vibration comprises a shaker.

6. The device according to claim 5 wherein the shaker induces vibration using one or more devices selected from the group consisting of a piezoelectric device, an electromagnetic device, an electromechanical device, a pneumatic device and a hydraulic device.

7. The device according to claim 1 wherein the means for measuring a tissue response comprises an impedance transducer.

8. The device according to claim 7 wherein the impedance transducer comprises a means for measuring an input and output signal.

9. The device according to claim 7 wherein the impedance transducer comprises one or more selected from the group consisting of an accelerometer, a displacement transducer and a load cell.

10. The device according to claim 1 further comprising one or more means for measuring localized tissue damage.

11. The device according to claim 10 wherein the means for measuring localized tissue damage comprises one or more remote devices selected from the group consisting of an accelerometer and a displacement transducer.

12. The device according to claim 11 wherein one or more of the remote devices further comprise a load cell.

13. The device according to claim 1 further comprising a power amplifier capable of increasing the signal from the signal generator.

14. An apparatus for measuring a frequency response comprising:

(a) a vibration generator comprised of one or more actuators selected from the group consisting of piezoelectric, electromagnetic, electromechanical, pneumatic and hydraulic actuators,

wherein the vibration generator is capable of inducing a vibration over the frequency range of low to high frequencies;

(b) an impedance transducer;

(c) one or more load cells, each in connection with a measure device of (b); and

wherein the device both (a), (b) and (c) are contained in a single housing and

wherein the apparatus is capable of vibration generation and responsive measurement at a single point of origin.

15. The apparatus according to claim 14 wherein the frequency range is from about 20 Hz to about 1.5 MHz.

16. The apparatus according to claim 14 wherein the impedance transducer comprises one or more selected from the group consisting of an accelerometer, displacement transducer and load cell.

17. A method for tissue quality assessment comprising:

(a) generating a vibration over a frequency range based on a given set of operational parameters;

(b) inputting said vibration into one or more tissues at a desired anatomic region;

(c) measuring the tissue response resulting from step (b) at the anatomic region used in step (b), and

(d) providing a user response based on the tissue response from step (c).

18. The method according to claim 17 wherein the frequency range is from about 20 Hz to about 1.5 MHz.

19. The method according to claim 17 wherein the frequency range is from about 20 Hz to about 600 kHz.

20. The method according to claim 17 wherein the frequency range is from about 800 Hz to about 1.5 MHz.

21. The method according to claim 17 further comprising selecting the operational parameters prior to step (a).

22. The method according to claim 21 wherein the operational parameters comprise one or more inputs selected from the group consisting of anatomic site, age, sex, body weight and shoe size.

23. The method according to claim 17 wherein the user response of step (d) comprises calculating a relative value based on comparative data from a database.

24. The method according to claim 17 wherein the user response of step (d) comprises calculating a relative value based on an analytical method.

25. The method according to claim 23 wherein the user response of step (d) comprises a diagnostic value for osteoporosis.

26. The method according to claim 17 wherein the user response of step (d) comprises a diagnostic value for bone fractures.

27. A method for testing an anatomical region, the method comprising:

(a) selecting an anatomical region for testing;

(b) selecting operational information;

(c) apply a force to the anatomical region to achieve constant contact pressure with the region;

(d) inducing a frequency sweep at the anatomical region while maintaining the contact pressure;

(e) collecting tissue response data; and

(f) providing a response based on the data from step (e).

28. The method according to claim 27 wherein the force applied is from about 10 N to about 100 N.

29. The method according to claim 27 wherein the constant contact pressure maintains a force from about 10 N to about 20 N.

30. The method according to claim 27 wherein the operational information comprised anatomic site, age, sex, body weight and shoe size.

31. The method according to claim 30 wherein the operational information further includes a file name.

32. The method according to claim 27 wherein the frequency sweep is from about 20 Hz to about 600 kHz.

33. The method according to claim 27 wherein the frequency sweep is from about 800 Hz to about 1.5 MHz.

34. The method according to claim 27 wherein step (f) comprises a confirmation that the data collected in step (e) was a valid sample.

35. The method according to claim 27 wherein step (f) comprises calculating one or more relative values based on comparative data from a database.

36. The method according to claim 27 wherein step (f) comprises

(i) confirming that the data collected in step (e) was a valid sample;

(ii) calculating one or more raw values based on the data collected in step (e);

(iii) comparing the raw values from (ii) to either;

(1) one or more previous calculated raw values for a given patient, or

(2) a database of similar values;

(iv) determining a relative diagnosis based on the comparison in step (iii); and

(v) communicating the relative diagnosis to a user.

37. The method according to claim 36 wherein the relative diagnosis comprises one or more forms selected from the group consisting of alpha-numeric characters, electronic data, graphs, pictures, video, charts, icons or sounds.