Modular auscultation sensor and telemetry system

• US 5,467,775 A
• Filed: 03/17/1995
• Issued: 11/21/1995
• Est. Priority Date: 03/17/1995
• Status: Expired due to Fees

• Current Assignee: University Research Engineers & Associates Incorporated
• Original Assignee: University Research Engineers & Associates Incorporated
• Inventors: Callahan, Thomas F., Callahan, Matthew G.
• Primary Examiner(s): Manuel, George
• Assistant Examiner(s): SCHAETZLE, KENNEDY
• Application Number:
  US08/405,879
• Time in Patent Office: 249 Days
• Field of Search: 128/715, 128/773, 181/131, 181/132, 381/67, D24/134
• US Class Current: 600/528
• CPC Class Codes: A61B 2562/0204 Acoustic sensors
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 7/04 Electric stethoscopes microphones, acoustic transducers therefor H04R

Abstract

A modular auscultation sensor and telemetry system ("MASTS") for sensing body sounds of a patient in a noisy environment where both desired body sounds and undesirable noise may be detected. The MASTS includes a transducer head that comprises two sensors that are substantially acoustically and mechanically isolated from each other. The first sensor is positioned to sense body sounds of a patient when the transducer head is placed against a patient'"'"'s skin, and the second sensor is positioned to sense primarily noise, if any. The sound signals are transmitted to a digital signal processor carried in a waist-pack or similar container. The digital signal processor processes the sound signals using an adaptive filter scheme to produce an output signal that is indicative of primarily of the body sounds emanating from the patient. A receiving device such as earphones, a hybrid noise reduction ("HNR") headset, an HNR helmet, a tape deck, or a computer may be plugged into the waist-pack and coupled to the digital signal processor to receive the output signals.

Claims

1. A modular auscultation sensor and telemetry system for use in sensing body sounds emanating from a living body, comprising:

a transducer head having a first chamber and a second chamber substantially acoustically isolated from said first chamber, wherein said first chamber has an opening, said transducer head comprising

a first sensor positioned adjacent to or in said first chamber, and

a second sensor positioned adjacent to or in said second chamber;

a telemetry conduit coupled to said transducer head and comprising a first signal conductor operably coupled to said first sensor and a second signal conductor operably coupled to said second sensor; and

a signal processor operably coupled to said first and second signal conductors for receiving signals from said first and second sensors and producing an output signal that is indicative of the body sounds emanating from a living body when the transducer head is brought in contact with a living body.

2. A modular auscultation sensor and telemetry system according to claim 1, further comprising a receiver operably coupled to said signal processor.

3. A modular auscultation sensor and telemetry system according to claim 2, wherein said receiver comprises speaker means for converting the output signal from said signal processor into audible sonic waves that may heard by a user.

4. A modular auscultation sensor and telemetry system according to claim 3, wherein said speaker means comprises a hybrid noise reduction headset.

5. A modular auscultation sensor and telemetry system according to claim 2, wherein said receiver comprises a computer.

6. A modular auscultation sensor and telemetry system according to claim 1, wherein said transducer head further comprises an outer housing and an inner housing positioned within said outer housing.

7. A modular auscultation sensor and telemetry system according to claim 2, wherein said outer housing has a channel and said transducer head further comprises an isolator positioned at least partially in said channel, said isolator having an interior chamber that at least partially constitutes said second chamber.

8. A modular auscultation sensor and telemetry system according to claim 7, wherein said isolator has at least one opening connecting said interior chamber to the exterior of said isolator, and said second sensor is positioned in said opening.

9. A modular auscultation sensor and telemetry system according to claim 7, wherein said isolator comprises an elastomer material.

10. A modular auscultation sensor and telemetry system according to claim 6, wherein said inner housing is positioned within said outer housing such that a chamber is formed therebetween, and wherein said chamber at least partially constitutes said second chamber.

11. A modular auscultation sensor and telemetry system according to claim 10, wherein said outer housing is provided with a channel and an opening connecting said channel to said chamber between said inner and outer housings, and said transducer head further comprises an isolator positioned at least partially in said channel, said isolator having an interior chamber and said second sensor being at least partially positioned in said interior chamber.

12. A modular auscultation sensor and telemetry system according to claim 6, wherein said inner housing has an inner chamber that defines said first chamber and an outer opening that defines said opening to said first chamber, and wherein said transducer head further comprises at least one isolator disposed between said inner and outer housings.

13. A modular auscultation sensor and telemetry system according to claim 12, wherein said at least one isolator comprises an elastomer material.

14. A modular auscultation sensor and telemetry system according to claim 12, wherein:

said at least one isolator includes a first isolator and a second isolator both disposed between said inner and outer housings,

said first isolator is disposed near a first end of said inner housing and said second isolator is disposed near a second end of said inner housing, and

said outer opening of said inner housing is located near said second end of said inner housing.

15. A modular auscultation sensor and telemetry system according to claim 14, wherein said transducer head further comprises a third isolator that at least partially surrounds said first sensor.

16. A modular auscultation sensor and telemetry system according to claim 15, wherein said third isolator has a generally wheel-like configuration with a substantially central through hole in which said sensor is at least partially received, an inner portion surrounding said central through hole, and a plurality of spoke members radiating outward from said inner portion such that spaces are formed between said spoke members.

17. A modular auscultation sensor and telemetry system according to claim 16, wherein said third isolator is positioned substantially within said inner chamber of said inner housing near said first end of said inner housing.

18. A modular auscultation sensor and telemetry system according to claim 16, wherein said third isolator is substantially positioned between a first wall of said inner housing and a first wall of said outer housing.

19. A modular auscultation sensor and telemetry system according to claim 18, wherein said first isolator is disposed at least partially between said third isolator and said first wall of said outer housing.

20. A modular auscultation sensor and telemetry system according to claim 15, wherein said transducer head further comprises a fourth isolator that at least partially surrounds said second sensor.

21. A modular auscultation sensor and telemetry system according to claim 20, wherein said outer housing has a channel and said fourth isolator is positioned at least partially within said channel.

22. A modular auscultation sensor and telemetry system according to claim 6, wherein:

said inner housing comprises first and second subchambers that are divided by a inwardly-extending protrusion of said inner housing that defines an inner opening between said first and second subchambers,

said first subchamber is defined by a surface of said protrusion and a circumferential side wall of said inner housing that is at an angle to said surface of said protrusion, and

said outer opening of said inner housing opens to said second subchamber; and

said transducer head further comprises a first isolator that at least partially surrounds said first sensor and is disposed substantially within said first subchamber of said inner housing.

23. A modular auscultation sensor and telemetry system according to claim 22, wherein:

said first isolator has a generally wheel-like configuration with a substantially central through hole in which said first sensor is at least partially received, a plurality of outer through holes spaced radially outward from said central through hole, and an outer side wall, said central through hole and said outer through holes extending from a first end of said first isolator to a second opposing end of said first isolator.

24. A modular auscultation sensor and telemetry system according to claim 23, wherein said circumferential side wall of said inner chamber is tapered such that said first chamber increases in diameter towards said outer opening, and said outer side wall of said first isolator substantially matches the taper of said circumferential side wall and is positioned adjacent to said circumferential side wall.

25. A modular auscultation sensor and telemetry system according to claim 24, wherein said transducer head further comprises a shim disposed between said second end of said first isolator and said surface of said protrusion.

26. A modular auscultation sensor and telemetry system according to claim 22, wherein said transducer head further comprises at least one isolator disposed between said inner and outer housings.

27. A modular auscultation sensor and telemetry system according to claim 26, wherein:

said at least one isolator includes a second isolator and a third isolator both disposed between said inner and outer housing,

said second isolator is disposed near a first end of said inner housing and said third isolator is disposed near a second end of said inner housing, and

said outer opening of said inner housing being located near said second end of said inner housing.

28. A modular auscultation sensor and telemetry system according to claim 22, wherein said second subchamber has a generally bell-shaped configuration defined by an inner surface of said inner housing that substantially follows the contour of a segment of an inverse paraboloid, and wherein said second subchamber at least partially constitutes said first chamber.

29. A modular auscultation sensor and telemetry system according to claim 28, wherein said first sensor is substantially aligned with an axis of symmetry of said inverse paraboloid.

30. A modular auscultation sensor and telemetry system according to claim 1, wherein a portion of said first chamber near said opening substantially follows the contour of an inverse paraboloid, and said first sensor is substantially aligned with an axis of symmetry of said inverse paraboloid.

31. A modular auscultation sensor and telemetry system according to claim 1, wherein said first sensor comprises a microphone, and said second sensor comprises a microphone.

32. A modular auscultation sensor and telemetry system according to claim 1, wherein said transducer head further comprises a diaphragm that extends across said opening of said first chamber.

33. A modular auscultation sensor and telemetry system according to claim 1, wherein said transducer head further comprises a shield that at least partially surrounds said outer housing.

34. A modular auscultation sensor and telemetry system according to claim 1, further comprising a portable pack in which said signal processor is positioned.

35. A modular auscultation sensor and telemetry system according to claim 1, wherein said first conductor comprises an electrical conductor and said second conductor comprises an electrical conductor.

36. A modular auscultation sensor and telemetry system for use in sensing body sounds emanating from a living body, comprising:

a transducer head having a first chamber and a second chamber substantially isolated from said first chamber, wherein said first chamber has an opening, said transducer head comprising

a first sensor positioned adjacent to or in said first chamber,

a second sensor positioned adjacent to or in said second chamber, and

a diaphragm that extends across said opening of said first chamber;

a telemetry conduit coupled to said transducer head and comprising a first signal conductor operably coupled to said first sensor and a second signal conductor operably coupled to said second sensor; and

digital signal processing means, operably coupled to said first and second conductors for receiving signals from said first and second sensors, processing said signals and producing an output signal that is indicative of body sounds when said diaphragm of said transducer head is brought into contact with a living body.

37. A modular auscultation sensor and telemetry system according to claim 36, wherein said digital signal processing means comprises:

a microprocessor that includes an adaptive filter for processing and conditioning samples of said signals from said second sensor and generating a filtered signal, and a subtractor for subtracting said filtered signal from said signal from said first sensor to generate said output signal that is indicative of the body sounds, wherein said output signal is fed back to said adaptive filter to dynamically adjust said adaptive filter.

38. A modular auscultation sensor and telemetry system according to claim 37, wherein said digital signal processing means further comprises:

an analog-to-digital converter that transforms said signals from said first and second sensors from analog signals to digital signals; and

a digital-to-analog converter that transforms said output signal from a digital signal to an analog signal.

39. A stethoscope comprising:

a transducer head having a first chamber and a second chamber substantially isolated from said first chamber, said transducer head comprising

an outer housing having an inner chamber,

an inner housing positioned within said inner chamber of said outer housing, said inner housing having an inner chamber that at least partially constitutes said first chamber, and an opening to said inner chamber;

a diaphragm that extends across said opening of said inner chamber,

a first sensor positioned adjacent to or in said first chamber of said inner housing, and

a second sensor positioned adjacent to or in said second chamber; and

a telemetry conduit coupled to said transducer head comprising a first signal conductor operably coupled to said first sensor and a second signal conductor operably coupled to said second sensor.

40. A stethoscope according to claim 39, wherein:

said transducer head further comprises a first isolator and a second isolator both disposed between said inner and outer housings,

said first isolator is disposed near a first end of said inner housing and said second isolator is disposed near a second end of said inner housing, and

said opening of said inner housing is located near said second end of said inner housing.

41. A stethoscope according to claim 40, wherein said transducer head further comprises a third isolator that at least partially surrounds said first sensor.

42. A stethoscope according to claim 41, wherein said transducer head further comprises a fourth isolator that at least partially surrounds said second sensor.

43. A stethoscope according to claim 42, wherein said outer housing has a channel and said fourth isolator is positioned at least partially in said channel.

44. A stethoscope according to claim 43, wherein said fourth isolator has an interior chamber that at least partially constitutes said second chamber.

45. A stethoscope according to claim 43, wherein said transducer head has a chamber formed between said inner housing and said outer housing that at least partially constitutes said second chamber, and wherein said outer housing has an opening connecting said channel to said chamber between said inner and outer housings, and said fourth isolator is positioned at least partially in said channel.