ADAPTIVE SAMPLING OF HEART SOUNDS

• US 20170252566A1
• Filed: 05/18/2017
• Published: 09/07/2017
• Est. Priority Date: 11/29/2006
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Stahmann, Jeffrey E., Siejko, Krzysztof Z., Haro, Carlos, Patangay, Abhilash, Carlson, Gerrard M., Belalcazar, Andres
• Granted Patent: US 10,729,909 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• 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 5/1116 Determining posture transitions
• CPC Class Codes: A61B 5/4806 Sleep evaluation A61B5/4821 takes precedence; devices for inducing sleep A61M21/02
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• CPC Class Codes: A61B 7/00 Instruments for auscultation
• CPC Class Codes: A61B 7/04 Electric stethoscopes microphones, acoustic transducers therefor H04R
• CPC Class Codes: A61N 1/36514 controlled by a physiological quantity other than heart potential, e.g. blood pressure controlled by two or more physical parameters A61N1/36585
• CPC Class Codes: A61N 1/36578 controlled by mechanical motion of the heart wall, e.g. measured by an accelerometer or microphone

Abstract

A system and method to sense heart sounds with one or more implantable medical devices according to one or more signal processing parameters. The method alters one or more of the parameters as a function of one or more physiologic triggering events. The method then senses heart sounds with the one or more implantable medical devices according to at least the one or more altered signal processing parameters.

Claims

1. (canceled)

2. A system comprising:

a control circuit;

a sensor, coupled to the control circuit, the sensor configured to sense energy and produce a heart sound signal;

a heart sound detector, coupled to the sensor and the control circuit, the heart sound detector configured to detect heart sounds within the heart sound signal; and

a triggering circuit, coupled to the control circuit, the triggering circuit configured to detect one or more physiologic triggering events,

wherein the control circuit is configured to identify a type of heart sound to sense as a function of the one or more physiologic triggering events, and to alter a heart sound signal processing parameter according to the identified type of heart sound to sense.

3. The medical device of claim 2, wherein, to alter the heart sound signal processing parameter, the control circuit is configured to select a signal sampling bit resolution based on the identified type of heart sound to sense, and

wherein the heart sound detector is configured to detect heart sounds according to the altered heart sound signal processing parameter.

4. The medical device of claim 3, wherein the control circuit is configured to select a first signal sampling bit resolution when the identified heart sound is an S3 heart sound and to select a second different signal sampling bit resolution when the identified heart sound is an S1 heart sound.

5. The medical device of claim 2, wherein, to alter the heart sound signal processing parameter, the control circuit is configured to change one or more of a noise blanking interval or a data acquisition buffer length based on the identified type of heart sound to sense.

6. The medical device of claim 5, wherein the control circuit is configured to change the data acquisition buffer length to include a segment of the heart sound signal that includes the identified type of heart sound.

7. An apparatus, comprising:

a control circuit configured to;

receive heart sound information sensed according to one or more heart sound signal processing parameters;

identify a type of heart sound to sense as a function of one or more detected physiologic triggering events; and

alter the one or more heart sound signal processing parameters according to the identified type of heart sound to sense.

8. The apparatus of claim 7, wherein the one or more heart sound signal processing parameters includes at least one of:

a signal sampling bit resolution;

a noise blanking interval;

or

a data acquisition buffer length.

9. The apparatus of claim 7, wherein the control circuit is configured to provide the altered one or more heart sound signal processing parameters to a heart sound detector configured to detect heart sounds using a sensed heart sound signal according to the one or more heart sound signal processing parameters.

10. A process of controlling a medical device, the process comprising:

receiving heart sound information sensed according to one or more heart sound signal processing parameters;

identifying, using a control circuit, a type of heart sound to sense as a function of one or more detected physiologic triggering events; and

altering, using the control circuit, the one or more heart sound signal processing parameters according to the identified type of heart sound to sense.

11. The process of claim 10, wherein altering the one or more heart sound signal processing parameters includes selecting a signal sampling bit resolution based on the identified type of heart sound to sense.

12. The process of claim 11, wherein selecting the signal sampling bit resolution includes selecting a first signal sampling bit resolution when the identified heart sound is an S3 heart sound and selecting a second different signal sampling bit resolution when the identified heart sound is an S1 heart sound.

13. The process of claim 11, wherein selecting the signal sampling bit resolution includes increasing the sampling bit resolution when the identified heart sound includes one of or more of a regurgitant heart murmur, a stenotic heart murmur sound, and a coronary vascular blood turbulence sound.

14. The process of claim 11, wherein selecting the signal sampling bit resolution includes selecting a first bit resolution when the identified heart sound is an S1 heart sound and selecting a second different bit resolution when the identified heart sound includes an S4 heart sound.

15. The process of claim 10, wherein identifying the type of heart sound to sense includes:

detecting an occurrence or change in a splitting of an S1 or an S2 heart sound, and

identifying the S1 or the S2 heart sound as the heart sound to sense in response to the detected occurrence or change in the splitting of the S1 or the S2 heart sound, and

wherein altering the one or more heart sound signal processing parameters includes selecting a sampling bit resolution according to the identified S1 or the S2 heart sound as the heart sound to sense, and the detected occurrence or change in the splitting of the S1 or the S2 heart sound.

16. The process of claim 10, including:

sensing heart sounds using a heart sound sensor according to the one or more heart sound signal processing parameters; and

synchronizing the sensing heart sounds with another physiological event as a function of the one or more detected physiologic triggering events.

17. The process of claim 10, wherein altering the one or more heart sound signal processing parameters includes selecting a data acquisition interval according to the identified type of heart sound to sense.

18. The process of claim 10, wherein altering the one or more heart sound signal processing parameters includes selecting a data acquisition buffer size according to the identified type of heart sound to sense.

19. The process of claim 10, wherein altering the one or more heart sound signal processing parameters includes changing one or more of a noise blanking interval and a data acquisition buffer length based on the identified type of heart sound to sense.

20. The process of claim 19, wherein changing the noise blanking interval includes changing the noise blanking interval to include a segment of the heart sound signal that does not include the identified type of heart sound.

21. The process of claim 19, wherein changing the data acquisition buffer length includes changing the data acquisition buffer length to include a segment of the heart sound signal that includes the identified type of heart sound.