ACOUSTIC RESPIRATORY MONITORING SENSOR HAVING MULTIPLE SENSING ELEMENTS

• US 20170079594A1
• Filed: 12/01/2016
• Published: 03/23/2017
• Est. Priority Date: 10/15/2009
• Status: Active Grant

• Current Assignee: Masimo Corporation
• Original Assignee: Masimo Corporation
• Inventors: Telfort, Valery G., Dimitrov, Dimitar, Trang, Phi
• Granted Patent: US 10,349,895 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 2560/0412 Low-profile patch shaped housings
• CPC Class Codes: A61B 2562/0204 Acoustic sensors
• CPC Class Codes: A61B 2562/182 Electrical shielding, e.g. using a Faraday cage
• CPC Class Codes: A61B 2562/222 Electrical cables or leads therefor, e.g. coaxial cables or ribbon cables
• CPC Class Codes: A61B 2562/227 Sensors with electrical connectors
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/02444 Details of sensor A61B5/02427 takes precedence
• CPC Class Codes: A61B 5/08 Detecting, measuring or recording devices for evaluating the respiratory organs A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/082 Evaluation by breath analysis, e.g. determination of the chemical composition of exhaled breath A61B5/083, A61B5/091 take precedence
• CPC Class Codes: A61B 5/145 Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissuemeasuring of blood pressure or blood flow A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• CPC Class Codes: A61B 5/4818 Sleep apnoea
• CPC Class Codes: A61B 5/6822 Neck
• CPC Class Codes: A61B 5/6833 Adhesive patches
• CPC Class Codes: A61B 5/721 using a separate sensor to detect motion or using motion information derived from signals other than the physiological signal to be measured
• CPC Class Codes: A61B 5/7214 using signal cancellation, e.g. based on input of two identical physiological sensors spaced apart, or based on two signals derived from the same sensor, for different optical wavelengths
• CPC Class Codes: A61B 7/003 Detecting lung or respiration noise
• CPC Class Codes: A61B 7/008 Detecting noise of gastric tract, e.g. caused by voiding
• CPC Class Codes: A61B 7/04 : Electric stethoscopes microphones, acoustic transducers therefor H04R
• CPC Class Codes: Y10T 29/49005 : Acoustic transducer

Abstract

According to certain described aspects, multiple acoustic sensing elements are employed in a variety of beneficial ways to provide improved physiological monitoring, among other advantages. In various embodiments, sensing elements can be advantageously employed in a single sensor package, in multiple sensor packages, and at a variety of other strategic locations in the monitoring environment. According to other aspects, to compensate for skin elasticity and attachment variability, an acoustic sensor support is provided that includes one or more pressure equalization pathways. The pathways can provide an air-flow channel from the cavity defined by the sensing elements and frame to the ambient air pressure.

Claims

1. (canceled)

2. An acoustic sensor comprising:

first and second piezoelectric elements each including respective first and second electrodes; and

a noise attenuator coupled to the first electrode of the first piezoelectric element and the first electrode of the second piezoelectric element, the noise attenuator configured to;

at least partially constructively combine a physiological signal component of a first signal output by the first piezoelectric element and a physiological signal component of a second signal output by the second piezoelectric element; and

at least partially destructively combine a noise component of the first signal output by the first piezoelectric element a noise component of the second signal output by the second piezoelectric element.

3. The acoustic sensor of claim 2, wherein the first piezoelectric element and the second piezoelectric element are arranged in a stack, and wherein the second electrode of the first piezoelectric element and the second electrode of the second piezoelectric element are coupled to a common potential.

4. The acoustic sensor of claim 3, wherein the first and second piezoelectric elements each comprise:

first electrode coatings disposed on surfaces of the respective piezoelectric elements corresponding to an outer portion of the stack; and

second electrode coatings disposed on surfaces of the respective piezoelectric elements corresponding to an inner portion of the stack,

wherein the first electrode coatings are configured to shield the second electrode coatings from electromagnetic noise.

5. The acoustic sensor of claim 2, wherein the noise attenuator comprises at least one of:

circuitry including an amplifier, a signal processor, or a general-purpose processor.

6. The acoustic sensor of claim 2, wherein the noise attenuator is further configured to generate a reduced noise signal based on constructively combining the physiological signal components and destructively combining the noise components.

7. The acoustic sensor of claim 6, wherein the reduced noise signal has a lower noise component than one or more of the first and second signals.

8. The acoustic sensor of claim 6, wherein the noise attenuator generates the reduced noise signal using common-mode rejection.

9. The acoustic sensor of claim 2 further comprising:

a coupling bump configured to apply pressure to at least one of the first and second piezoelectric elements to push at least a portion of the one of the first and second piezoelectric elements into a cavity of the acoustic sensor.

10. The acoustic sensor of claim 9, wherein the coupling bump is configured to transmit acoustic vibrations to the one of the first and second piezoelectric elements through the acoustic coupling bump when the acoustic sensor is attached to the medical patient.

11. A method comprising:

receiving signals from an acoustic sensor that is attachable to a medical patient and configured to provide the signals responsive to acoustic vibrations indicative of one or more physiological parameters of the medical patient, the acoustic sensor including first and second piezoelectric elements each including respective first and second electrodes; and

by a noise attenuator;

at least partially constructively combine a physiological signal component of a first signal output by the first piezoelectric element and a physiological signal component of a second signal output by the second piezoelectric element; and

at least partially destructively combine a noise component of the first signal output by the first piezoelectric element a noise component of the second signal output by the second piezoelectric element,

wherein the noise attenuator is coupled to the first electrode of the first piezoelectric element and the first electrode of the second piezoelectric element.

12. The method of claim 11, wherein the first piezoelectric element and the second piezoelectric element are arranged in a stack, and wherein the second electrode of the first piezoelectric element and the second electrode of the second piezoelectric element are coupled to a common potential.

13. The method of claim 12, wherein the first and second piezoelectric elements each comprise:

first electrode coatings disposed on surfaces of the respective piezoelectric elements corresponding to an outer portion of the stack; and

second electrode coatings disposed on surfaces of the respective piezoelectric elements corresponding to an inner portion of the stack,

wherein the first electrode coatings are configured to shield the second electrode coatings from electromagnetic noise.

14. The method of claim 11, wherein the noise attenuator comprises at least one of:

circuitry including an amplifier, a signal processor, or a general-purpose processor.

15. The method of claim 11 further comprising:

by the noise attenuator, generating a reduced noise signal based on constructively combining the physiological signal components and destructively combining the noise components.

16. The method of claim 15, wherein the reduced noise signal has a lower noise component than one or more of the first and second signals.

17. The method of claim 15, wherein the noise attenuator generates the reduced noise signal using common-mode rejection.

18. The method of claim 11, wherein the acoustic sensor further includes a coupling bump configured to apply pressure to at least one of the first and second piezoelectric elements to push at least a portion of the one of the first and second piezoelectric elements into a cavity of the acoustic sensor.

19. The method of claim 18, wherein the coupling bump is configured to transmit acoustic vibrations to the one of the first and second piezoelectric elements through the acoustic coupling bump when the acoustic sensor is attached to the medical patient.

20. A method comprising:

at least partially constructively combining, by a noise attenuator, a physiological signal component of a first signal received from a first piezoelectric element of an acoustic sensor and a physiological signal component of a second signal received from a second piezoelectric element of the acoustic sensor; and

at least partially destructively combining, by the noise attenuator, a noise component of the first signal received from the first piezoelectric element a noise component of the second signal received from the second piezoelectric element,

wherein the noise attenuator is coupled to a first electrode of the first piezoelectric element and a first electrode of the second piezoelectric element.

21. The method of claim 20, wherein a second electrode of the first piezoelectric element and a second electrode of the second piezoelectric element are coupled to a common potential.

22. The method of claim 21, wherein the first and second piezoelectric elements are each stretched from a first side of a cavity of the acoustic sensor to a second side of the cavity of the acoustic sensor.