ACOUSTIC RESPIRATORY MONITORING SENSOR HAVING MULTIPLE SENSING ELEMENTS

• US 20190142344A1
• Filed: 11/16/2018
• Published: 05/16/2019
• 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 10,925,544 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 system comprising:

a first acoustic sensor comprising;

a first inner layer;

a first sensing element; and

a first outer layer; and

a second acoustic sensor comprising;

a second inner layer;

a second sensing element; and

a second outer layer,

wherein the first and second acoustic sensors are arranged in a stack,

wherein the first and second inner layers are positioned between the first and second sensing elements,

wherein the first and second sensing elements are positioned between the first and second outer layers, and

wherein the first and second outer layers are configured to shield the first and second inner layers from electromagnetic noise.

3. The acoustic sensor system of claim 2, wherein the first and second outer layers are coupled to a common potential.

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

5. The acoustic sensor system of claim 4, wherein the first and second inner layers and the first and second outer layers comprise electrode coatings.

6. The acoustic sensor system of claim 5, wherein the first inner layer covers a first percentage of an inner surface area of the first sensing element, and wherein the first outer layer covers a second percentage of an outer surface area of the first sensing element, the second percentage greater than the first percentage.

7. The acoustic sensor system of claim 6, wherein the second inner layer covers a third percentage of an inner surface area of the second sensing element, and wherein the second outer layer covers a fourth percentage of an outer surface area of the second sensing element, the fourth percentage greater than the third percentage.

8. The acoustic sensor system of claim 7, wherein the first acoustic sensor produces a first signal in response to acoustic vibrations and provides the first signal to a noise attenuator, and wherein the second acoustic sensor produces a second signal in response to acoustic vibrations and provides the second signal to the noise attenuator, wherein the noise attenuator is responsive to the first and second signals to produce a reduced noise signal having a higher signal to noise ratio than either of the first or second signals.

9. The acoustic sensor system of claim 8, wherein the first and second outer layers distribute electromagnetic noise incident on the acoustic sensor system substantially evenly between the first signal and the second signal.

10. The acoustic sensor system of claim 9, wherein the electromagnetic noise in the first signal is substantially in phase with the electromagnetic noise in the second signal.

11. The acoustic sensor system of claim 10, further comprising an intermediate layer positioned between the first and second inner layers, the intermediate layer configured electrically insulate the first and second acoustic sensors from one another.

12. The acoustic sensor system of claim 11, wherein the intermediate layer forms a substantially water resistant seal between the first and second acoustic sensors.

13. The acoustic sensor system of claim 12, wherein the intermediate layer is configured to at least partially bond the first and second sensors together such that mechanically active regions of the first and second sensing elements move together in response to acoustic vibrations.

14. The acoustic sensor system of claim 5 further comprising:

a noise attenuator coupled to the first inner layer of the first acoustic sensor and the second inner layer of the second acoustic sensor, the noise attenuator configured to;

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

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

15. The acoustic sensor system of claim 14, wherein the noise attenuator comprises at least one of:

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

16. The acoustic sensor system of claim 15, 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.

17. The acoustic sensor system of claim 16, wherein the reduced noise signal has a lower noise component than one or more of the first and second signals.

18. The acoustic sensor system of claim 17, wherein the noise attenuator generates the reduced noise signal using common-mode rejection.

19. A method comprising:

receiving signals from an acoustic sensor system according to claim 2 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.

20. The method of claim 19, wherein the acoustic sensor system further includes a coupling bump configured to apply pressure to at least one of the first and second sensing elements to push at least a portion of the one of the first and second sensing elements into a cavity of the acoustic sensor system.

21. The method of claim 20, wherein the coupling bump is configured to transmit acoustic vibrations to the one of the first and second sensing elements through the acoustic coupling bump when the acoustic sensor is attached to the medical patient.