Weighted bioacoustic sensor and method of using same

• US 7,998,091 B2
• Filed: 11/23/2005
• Issued: 08/16/2011
• Est. Priority Date: 11/23/2005
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: DeRoos, Fred L., Carim, Hatim M., Bharti, Vivek
• Primary Examiner(s): Hindenburg; Max
• Assistant Examiner(s): Eiseman; Adam J
• Application Number:
  US11/287,179
• Publication Number:
  US 20070113654A1
• Time in Patent Office: 2,092 Days
• Field of Search: 734/31, 736/49, 181/126, 181/131, 181/132, 181/137, 181/167, 600/534, 600/535, 600/586, 381/67
• US Class Current: 600/586
• CPC Class Codes: A61B 2562/0204 Acoustic sensors
• CPC Class Codes: A61B 7/04 Electric stethoscopes microphones, acoustic transducers therefor H04R
• CPC Class Codes: G01N 2291/0255 (Bio)chemical reactions, e.g. on biosensors
• CPC Class Codes: G01N 2291/101 one transducer
• CPC Class Codes: G01N 29/14 using acoustic emission techniques echo of particles G01N29/046; measuring mechanical vibrations or acoustic waves in solids in general G01H1/00
• CPC Class Codes: G01N 29/2437 Piezoelectric probes
• CPC Class Codes: G01N 29/46 by spectral analysis, e.g. Fourier analysis or wavelet analysis spectral signal processing per se G06F17/14

Abstract

A sensor for sensing bioacoustic energy includes a housing comprising an interfacing portion configured to establish coupling with a body part during use. The sensor includes a transducer element coupled to the interfacing portion of the housing and configured to sense sounds produced by matter of biological origin. One or more conductors are coupled to the transducer element. A mass element is compliantly coupled to a surface of the transducer element. Intervening material is disposed between the transducer element surface and the mass element, and allows for differential motion between the transducer element surface and the mass element during excitation of the transducer element.

Claims

1. A bioacoustic sensor, comprising:

a housing comprising an interfacing portion configured to establish coupling with a body part during use;

a transducer assembly comprising;

a transducer element coupled to the interfacing portion of the housing and configured to sense sound within a frequency range produced by matter of biological orgin, the transducer element configured to modulate or generate a signal in response to deformation of the transducer element; and

a mass element compliantly coupled to a surface of the transducer element, the mass element positioned to improve the sensitivity of the transducer element in the frequency range, such that the transducer element includes a substantially uniform broadband improved sensitivity in the frequency range, wherein the transducer assembly is mounted on the inner surface of the interfacing portion within the housing so that the transducer element is preferentially sensitive to bioacoustic energy transmitted to the transducer element via the interfacing portion; and

one or more conductors coupled to the transducer element.

2. The sensor of claim 1, wherein the mass element and transducer element are configured to amplify a signal producible by the transducer element.

3. The sensor of claim 1, wherein the mass element and transducer element are configured to allow for mechanical deformation of the transducer element in response to bioacoustic energy impinging on the transducer element.

4. The sensor of claim 1, wherein at least a surface of the mass element facing the transducer element has a high reflection coefficient to acoustic waves.

5. The sensor of claim 1, wherein the mass element covers substantially all of an effective transducing portion of the transducer element surface.

6. The sensor of claim 1, wherein the mass element comprises metal or non-metallic material.

7. The sensor of claim 1, wherein the mass element has a substantially uniform weight distribution profile relative to an x-y plane of the transducer element.

8. The sensor of claim 1, wherein the mass element has a substantially non-uniform weight distribution profile relative to an x-y plane of the transducer element.

9. The sensor of claim 1, wherein the mass element comprises a plurality of discrete mass arrangements.

10. The sensor of claim 1, wherein the mass element is a unitary mass element.

11. The sensor of claim 1, wherein the transducer element comprises a polymeric piezoelectric film.

12. The sensor of claim 1, wherein the transducer element comprises piezoresistive material, one or more strain gauges, one or more capacitive elements, ceramic material or crystalline material.

13. The sensor of claim 1, wherein the transducer element further comprises a laminate structure, the laminate structure comprising piezoelectric film, a weight in film form, and one or more adhesive layers.

14. The sensor of claim 1, wherein the transducer element is configured for auscultation.

15. The sensor of claim 1, wherein the sensor comprises an arrangement configured to modify a frequency response of the transducer element.

16. The sensor of claim 1, wherein the at least one conductor comprises at least one optical conductor.

17. The sensor of claim 16, wherein the at least one optical conductor is coupled to converter circuitry, the converter circuitry situated remote from the sensor and configured to convert a received optical signal to an output electrical signal.

18. The sensor of claim 17, wherein the converter circuitry is coupled to one or more electrical-to-audio converters.

19. The sensor of claim 1, wherein the housing comprises a base and a cover, the base comprising the interfacing portion and the cover coupled to the base via a compliant joint arrangement.

20. The sensor of claim 1, wherein the housing comprises a base and a cover, the cover comprising acoustically absorptive material.

21. The sensor of claim 1, wherein the interfacing portion of the housing is substantially stiff.

22. The sensor of claim 1, wherein the interfacing portion of the housing comprises a polymeric material, metal or alloy, a composite material, a ceramic material, or a crystalline material.

23. The sensor of claim 1, comprising a fixing arrangement coupled to the housing and configured to establish affixation between the housing and the body part during use.

24. The sensor of claim 1, comprising an adhesion arrangement coupled to the housing and configured to establish adhesive coupling between the housing and the body part during use.

25. The sensor of claim 1, further comprising signal conditioning circuitry coupled to the transducer member and disposed at, near, or integrally or in a unitary relationship with respect to the transducer member.

26. A sensor unit comprising a plurality of the transducer elements according to claim 1, wherein each of the plurality of transducer elements is configured to have a frequency response differing from that of at least one other transducer element of the plurality of transducer elements.

27. A sensor unit of claim 26, wherein each of the plurality of transducer elements has a stiffness, weight, shape, and thickness, at least one of the stiffness, weight configuration, shape, and thickness of each of the plurality of transducer elements differing from that of at least one other transducer element of the plurality of transducer elements.

28. A sensor unit of claim 26, wherein each of the plurality of transducer elements is supported from the housing by a common anchoring arrangement or separate anchoring arrangements.

29. A sensor unit of claim 26, further comprising gain control circuitry, wherein a gain response of each of the plurality of transducer elements is selectably adjustable via the gain control circuitry.

30. A sensor unit of claim 1, further comprising:

an auxiliary transducer element disposed within the housing other than at the interfacing portion of the housing; and

noise cancellation circuitry coupled to the transducer element and the auxiliary transducer.

31. A stethoscope comprising the sensor according to claim 1.

32. A helmet comprising one or more sensors according to claim 1, wherein the one or more sensors comprise one or more of the plurality of the transducer elements.

33. The sensor of claim 1, comprising communications circuitry configured to facilitate wired or wireless communication between the sensor and a device external of the housing.

34. The sensor of claim 1, further comprising signal processing circuitry coupled to the transducer element.

35. The sensor of claim 34, wherein the signal processing circuitry comprises digital and analog signal processing hardware and software circuitry coupled to the transducer element.

36. The sensor of claim 1, further comprising an intervening material disposed between the transducer element surface and the mass element, the intervening material allowing for differential motion between the transducer element surface and the mass element during excitation of the transducer element.

37. The sensor of claim 36, wherein the intervening material is capable of transmitting sound signals.

38. The sensor of claim 36, wherein the intervening material comprises an adhesive.

39. The sensor of claim 36, wherein the intervening material has a low acoustic impedance.

40. The sensor of claim 36, wherein the mass element comprises a mass and a stiff sheet, film or membrane having a first surface and a second surface, the first surface arranged to contact the intervening material and the mass disposed adjacent the second surface.

41. The sensor of claim 1, wherein the frequency range is 10 Hz to 700 Hz.

42. The sensor of claim 1, wherein the sensor is configured to have broadband sensitivity to normal and abnormal biological sounds.

52. The sensor of claim 40, wherein at least the first surface of the stiff sheet, film or membrane has a high reflection coefficient to acoustic waves.

43. A method of sensing bioacoustic energy using a transducer disposed in a housing comprising an interfacing portion configured to establish coupling with a body part during use, the method comprising:

providing the transducer coupled to the housing, wherein the transducer is mounted on the inner surface of the interfacing portion within the housing so that the transducer element is preferentially sensitive to a bioacoustic energy transmitted to the transducer element via the interfacing portion;

providing a stiff mass coupled to the transducer opposite the housing;

exciting the transducer in response to bioacoustic energy;

facilitating differential motion between the transducer and the stiff mass during excitation of the transducer;

modulating or generating a signal by the transducer in response to the excitation of the transducer; and

improving the sensitivity of the transducer with the stiff mass across a frequency range, such that the transducer includes a substantially uniform broadband improved sensitivity in the frequency range.

44. The method of claim 43, further comprising establishing coupling between the interfacing portion of the sensor housing and a body part from which the bioacoustic energy emanates.

45. The method of claim 43, wherein the signal is an electrical signal, the method further comprising converting the electrical signal to an optical signal and transmitting the optical signal remotely of the sensor housing.

46. The method of claim 43, comprising performing noise cancellation using the transducer element and at least one auxiliary transducer element disposed within the housing.

47. The method of claim 43, comprising establishing communication between a device disposed within the sensor housing and a device external of the sensor housing.

48. The method of claim 43, comprising performing signal processing or conditioning on the signal.

49. A bioacoustic sensor, comprising:

a housing comprising an interfacing portion configured to establish coupling with a body part during use;

a transducer assembly comprising;

a transducer element coupled to the interfacing portion of the housing and configured to sense sounds within a frequency range produced by matter of biological origin, the transducer element configured to modulate or generate a signal in response to deformation of the transducer element; and

a stiffening layer coupled to a surface of the transducer element, the stiffening layer positioned to improve the sensitivity of the transducer element in the frequency range, such that the transducer element includes a substantially uniform broadband improved sensitivity in the frequency range, wherein the transducer assembly is mounted on the inner surface of the interfacing portion within the housing so that the transducer element is preferentially sensitive to bioacoustic energy transmitted to the transducer element via the interfacing portion; and

one or more conductors coupled to the transducer element.

50. The sensor of claim 49, wherein the stiffening layer is coupled to the transducer element opposite the housing.

51. The sensor of claim 49, further comprising a mass element coupled to the stiffening layer, such that the stiffening layer is coupled between the mass element and the transducer element.

53. A bioacoustic sensor, comprising:

a housing comprising an interfacing portion configured to establish coupling with a body part during use and an inner surface opposite the interfacing portion;

a transducer element having an interfacing surface and coupled to the interfacing portion of the housing and configured to sense sounds within a frequency range produced by matter of biological origin, the transducer element configured to modulate or generate a signal in response to deformation of the transducer element, wherein the interfacing surface is directly affixed to the inner surface;

one or more conductors coupled to the transducer element; and

a mass element compliantly coupled to a surface opposite the first surface of the transducer element, the mass element positioned to improve the sensitivity of the transducer element in the frequency range, such that the transducer element includes a substantially uniform broadband improved sensitivity in the frequency range.