Bioacoustic sensor with active noise correction

Patent metadata

Field	Value
Publication number	US-9462994-B2
Application number	US-201314400082-A
Country	US
Kind code	B2
Filing date	May 9, 2013
Priority date	May 11, 2012
Publication date	Oct 11, 2016
Grant date	Oct 11, 2016

Abstract

A bioacoustic sensor assembly is described including a transducer generating an acoustic signal and an actuator configured to deform a portion of the transducer to increase a signal-to-noise ratio of the acoustic signal. The disclosure also provides methods and systems for reducing the impact of noise vibrations at the transducer.

First claim

We claim:

1. A system for acquiring bioacoustic signals, the system comprising:
a transducer assembly including a transducer configured to sense a manifestation of acoustic energy and an actuator physically coupled to a major surface of the transducer, wherein the transducer is configured to generate an acoustic signal;
a reference sensor configured to generate a reference signal;
a processor coupled to the reference sensor and the transducer; and
noise vibration control circuitry coupled to the reference sensor and the actuator, the noise vibration control circuitry configured to generate an anti-noise signal based at least partially on a component of the reference signal, the anti-noise signal operable to cause the actuator to deform at least a portion of the transducer, wherein the deformation of the transducer increases a signal-to-noise ratio of the acoustic signal.

2. The system of claim 1 , wherein the transducer is coupled to the actuator by an electrically insulating material.

3. The system of claim 1 , wherein at least one of the transducer and the actuator comprises a piezoelectric material.

4. The system of claim 1 , wherein the references signal comprises a component representative of noise, the noise comprising at least one of environmental and structure borne noise.

5. The system of claim 1 , wherein the actuator is operable to deform the transducer by applying mechanical energy to at least a portion of the first major surface of the transducer.

6. The system of claim 1 , wherein the deformation of the transducer comprises reducing at least a portion of a vibration sensed at the transducer, the portion of vibration being reduced indicative of unwanted noise and wherein the extent of deformation corresponds at least partially to a component of the reference signal.

7. A bioacoustic sensor comprising:
a housing configured for hand-held manipulation;
a transducer assembly supported by the housing that senses auscultation signals, the transducer assembly comprising a transducer having a first major surface and an actuator physically coupled to the transducer;
a headset coupled to the housing and configured to deliver audio corresponding to the auscultation signals through earpieces on the headset;
a reference sensor configured to generate a reference signal;
a processor disposed in the housing and configured to convert the auscultation signals to first digital signals representative of the auscultation signals; and
noise vibration control circuitry coupled to the reference sensor and the actuator, the noise vibration control circuitry configured to generate an anti-noise signal, wherein the anti-noise signal is based at least partially on a component of the reference signal and is operable to cause the actuator to deform at least a portion of the transducer, and wherein the deformation of the transducer increases a signal-to-noise ratio of the acoustic signal.

8. The bioacoustic sensor of claim 7 , wherein the transducer assembly further comprises an electrical insulating material disposed between the transducer and the actuator.

9. The bioacoustic sensor of claim 8 , wherein the transducer and the actuator comprise piezoelectric material.

10. The bioacoustic sensor of claim 7 , wherein the housing comprises a chamber having an opening to the exterior environment so that ambient noise may enter the chamber, wherein the housing comprises an interfacing portion configured to establish coupling with a body part during use and an inner surface opposite the interfacing portion, wherein a second major surface of the transducer is coupled to the inner surface of the housing, wherein the actuator is coupled to the first major surface opposite the second major surface of the transducer and wherein the actuator does not extend to the periphery of the transducer.

11. A method of increasing the signal-to-noise ratio of a signal generated by an acoustic sensor, the method comprising:
providing a transducer assembly and a reference sensor remote from the assembly, wherein the transducer assembly comprises a transducer and an actuator coupled to a major surface of the transducer;
providing noise vibration control circuitry coupled to the reference sensor and the actuator;
generating an acoustic signal from the transducer and a reference signal from the reference sensor;
providing at least the reference signal to the noise vibration control circuitry;
generating an anti-noise signal based at least partially on a component of the reference signal;
providing the anti-noise signal to the actuator; and
deforming at least a portion of the transducer via the actuator.

12. The method of claim 11 , wherein deforming the transducer comprises transferring mechanical energy via the actuator to at least a portion of the major surface of the transducer.

13. The method of claim 12 , wherein the magnitude of the energy is determined at least partially by at least one characteristic of a component of the reference signal.

14. The method of claim 11 , wherein generating an anti-noise signal comprises filtering the reference signal and the acoustic signal through an adaptive filter.

Assignees

• 3M Innovative Properties Co

Inventors

• Rogers Daniel J
• Tungjunyatham Justin
• Roed Christopher J

Classifications

• H04R1/46

  Special adaptations for use as contact microphones, e.g. on musical instrument, on stethoscope (throat mountings H04R1/14) · CPC title

• H04R2410/05

  Noise reduction with a separate noise microphone · CPC title

• H04R17/025

  using a piezoelectric polymer · CPC title

• A61B7/04 Primary

  Electric stethoscopes · CPC title

• A61B5/7203

  for noise prevention, reduction or removal · CPC title