Acoustic detection of vascular conditions

• US 20020099286A1
• Filed: 01/15/2002
• Published: 07/25/2002
• Est. Priority Date: 01/16/2001
• Status: Active Grant

• Current Assignee: Biomedical Acoustic Research Corporation
• Original Assignee: Biomedical Acoustic Research Corporation
• Inventors: Sandler, Richard H., Mansy, Hussein A.
• Granted Patent: US 6,780,159 B2
• Time in Patent Office: Days
• US Class Current: 600/407
• CPC Class Codes: A61B 2562/0204 Acoustic sensors
• CPC Class Codes: A61B 5/026 Measuring blood flow A61B3/1233, A61B3/1241 take precedence
• CPC Class Codes: A61B 5/6824 Arm or wrist
• CPC Class Codes: A61B 7/00 Instruments for auscultation
• CPC Class Codes: A61B 7/026 comprising more than one sound collector
• CPC Class Codes: A61M 1/3656 Monitoring patency or flow at connection sites; Detecting disconnections
• CPC Class Codes: A61M 2205/3375 Acoustical, e.g. ultrasonic, measuring means

Abstract

A system and method of detecting a vascular condition within a body receives vibrations emitted in response to blood flowing through a vascular structure within the body and converts the received vibrations into vibration information. The system and method generates spectral information from the vibration information, calculates a spectral parameter based on the spectral information and detects the vascular condition based on the spectral parameter.

Claims

1. A method of detecting a vascular condition within a body, the method comprising:

receiving vibrations emitted in response to blood flowing through a vascular structure within the body;

converting the received vibrations into vibration information;

generating spectral information from the vibration information;

calculating a spectral parameter based on the spectral information; and

detecting the vascular condition based on the spectral parameter.

2. The method of claim 1, wherein receiving the vibrations emitted in response to the blood flowing through the vascular structure within the body includes receiving the vibrations at one of a vibration sensor located adjacent to an outer surface of the body and a plurality of vibration sensors located adjacent to the outer surface of the body.

3. The method of claim 1, wherein receiving the vibrations emitted in response to the blood flowing through the vascular structure within the body includes receiving vibrations emitted in response to the blood flowing through one of a shunt, a vein and an artery.

4. The method of claim 1, wherein generating spectral information from the vibration information includes calculating an autospectrum based on the vibration information and identifying groups of spectral data, each of which corresponds to one of a plurality of cardiac cycles associated with the body.

5. The method of claim 1, wherein calculating the spectral parameter based on the spectral information includes calculating a time dependent dominant frequency.

6. The method of claim 1, wherein calculating the spectral parameter based on the spectral information includes calculating a time dependent amplitude signal and calculating an amplitude ratio based on the time dependent amplitude signal.

7. The method of claim 1, wherein calculating the spectral parameter based on the spectral information includes calculating a plurality of energy values associated with a respective plurality of frequency bands within the spectral information and calculating an energy ratio based on the plurality of energy values.

8. The method of claim 1, wherein generating the spectral information from the vibration information includes aligning groups of data, each of which is associated with one of a plurality of cardiac cycles, and averaging the aligned groups of data to generate an average time dependent spectrum for the plurality of cardiac cycles.

9. The method of claim 1, wherein detecting the vascular condition based on the spectral parameter includes comparing the spectral parameter to a reference value.

10. The method of claim 9, wherein comparing the spectral parameter to the reference value includes comparing the spectral parameter to a value indicative of an abnormal vascular condition.

11. The method of claim 10, wherein comparing the spectral parameter to the value indicative of the abnormal condition includes comparing the spectral parameter to a value associated with one of a vascular patency, a vascular occlusion and a vascular stenosis.

12. The method of claim 1, wherein generating spectral information from the vibration information includes identifying groups of temporal data, each of which is associated with one of a plurality of cardiac cycles, and averaging the groups of temporal data to generate an average time domain signal representative of an average cardiac cycle.

13. The method of claim 12, wherein generating spectral information from the vibration information further includes subtracting the average time domain signal from each of the groups of temporal data.

15. The system of claim 14, wherein the vibration information is detected by a vibration sensor located adjacent to a vascular structure within the body.

16. The system of claim 15, wherein the vibration sensor is adapted to detect vibrations associated with blood flowing through the vascular structure.

17. The system of claim 15, wherein the vascular structure within the body is one of a shunt, an artery and a vein.

18. The system of claim 14, wherein the vibration information is detected by a plurality of vibration sensors, at least one of which is located adjacent to a structure within the body.

19. The system of claim 14, wherein the processor is further programmed to calculate an autospectrum based on the vibration information and to identify groups of spectral data, each of which corresponds to one of a plurality of cardiac cycles.

20. The system of claim 14, wherein the processor is further programmed to calculate a time dependent dominant frequency.

21. The system of claim 14, wherein the processor is further programmed to calculate a time dependent amplitude signal and to calculate an amplitude ratio based on the time dependent amplitude signal.

22. The system of claim 14, wherein the processor is further programmed to calculate a plurality of energy values associated with a respective plurality of frequency bands within the spectral information and to calculate an energy ratio based on the plurality of energy values.

23. The system of claim 14, wherein the processor is further programmed to align groups of data, each of which is associated with one of a plurality of cardiac cycles, and to average the aligned groups of data to generate an average time dependent spectrum for the plurality of cardiac cycles.

24. The system of claim 14, wherein the processor is further programmed to compare the spectral parameter to a reference value.

25. The system of claim 14, wherein the processor is further programmed to compare the spectral parameter to a value indicative of an abnormal vascular condition.

26. The system of claim 14, wherein the processor is further programmed to compare the spectral parameter to a value associated with one of a vascular patency, a vascular occlusion and a vascular stenosis.

27. The system of claim 14, wherein the processor is further programmed to identify groups of temporal data, each of which is associated with one of a plurality of cardiac cycles, and to average the groups of temporal data to generate an average time domain signal representative of an average cardiac cycle.

28. The system of claim 27, wherein the processor is further programmed to subtract the average time domain signal from each of the groups of temporal data.

30. The system of claim 29, wherein the first software is further adapted to receive vibration information from a plurality of vibration sensors, at least one of which is located adjacent to the vascular structure.

31. The system of claim 29, wherein the second software is further adapted to calculate an autospectrum based on the vibration information and to identify groups of spectral data, each of which corresponds to one of a plurality of cardiac cycles.

32. The system of claim 29, wherein the third software is further adapted to calculate a time dependent dominant frequency.

33. The system of claim 29, wherein the third software is further adapted to calculate a time dependent amplitude signal and to calculate an amplitude ratio based on the time dependent amplitude signal.

34. The system of claim 29, wherein the third software is further adapted to calculate a plurality of energy values associated with a respective plurality of frequency bands within the spectral information and to calculate an energy ratio based on the plurality of energy values.

35. The system of claim 29, wherein the second software is further adapted to align groups of data, each of which is associated with one of a plurality of cardiac cycles, and to average the aligned groups of data to generate an average time dependent spectrum for the plurality of cardiac cycles.

36. The system of claim 29, wherein the fourth software is further adapted to compare the spectral parameter to a reference value.

37. The system of claim 29, wherein the fourth software is further adapted to compare the spectral parameter to a value indicative of an abnormal vascular condition.

38. The system of claim 29, wherein the fourth software is further adapted to compare the spectral parameter to a value associated with one of a vascular patency, a vascular occlusion and a vascular stenosis.

39. The system of claim 29, further including a fifth software adapted to be executed by the processor to identify groups of temporal data, each of which is associated with one of a plurality of cardiac cycles, and to average the groups of temporal data to generate an average time domain signal representative of an average cardiac cycle.

40. The system of claim 39, wherein the fifth software is further adapted to subtract the average time domain signal from each of the groups of temporal data.

14. A system for detecting a vascular condition within a body, the system comprising:

a memory;

a processor communicatively coupled to the memory, wherein the processor is adapted to receive vibration information, wherein the processor is programmed to generate spectral information from the vibration information and to calculate a spectral parameter based on the spectral information and wherein the processor is programmed to detect the vascular condition based on the spectral parameter.

29. A system for detecting a vascular condition within a body, the system comprising:

a memory;

a first software adapted to be executed by a processor to receive vibration information associated with the vascular condition;

a second software adapted to be executed by the processor to generate spectral information from the vibration information;

a third software adapted to be executed by the processor to calculate a spectral parameter based on the spectral information; and

a fourth software adapted to be executed by the processor to detect the vascular condition based on the spectral parameter.