MEDICAL DEVICE WITH ADAPTIVE POWER CONSUMPTION

• US 20170095215A1
• Filed: 09/30/2016
• Published: 04/06/2017
• Est. Priority Date: 10/02/2015
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Watson, James N., Bartlett, Daniel, Addison, Paul S.
• Granted Patent: US 10,299,734 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 2560/0209 adapted for power saving
• CPC Class Codes: A61B 2560/0214 of power generation or supply
• 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 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/1123 Discriminating type of movement, e.g. walking or running A61B5/1116, A61B5/112 take precedence
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• 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 5/7285 for synchronising or triggering a physiological measurement or image acquisition with a physiological event or waveform, e.g. an ECG signal A61B6/5205, A61B6/541, A61B8/5207, A61B8/543 take precedence

Abstract

A system may include a photoplethysmograph (PPG) sensor configured to be secured to a patient and to generate a PPG signal for the patient. The system may also include a motion sensor configured to generate a motion signal indicative of motion of the patient. Further, the system may include a controller configured to receive the PPG signal from the PPG sensor and the motion signal from the motion sensor, to analyze the motion signal to detect motion of the patient, and to deactivate the at least one emitter of the PPG sensor based on the analysis of the motion signal when motion of the patient is detected.

Claims

1. A system, comprising:

a photoplethysmograph (PPG) sensor comprising at least one emitter configured to emit light into a tissue of a patient when activated and at least one detector configured to detect the light after interaction with the tissue and to generate a PPG signal based on the detected light;

a motion sensor configured to generate a motion signal indicative of motion of the patient; and

a processor configured to receive the PPG signal from the PPG sensor and the motion signal from the motion sensor, to analyze the motion signal to detect motion of the patient, and to deactivate the at least one emitter of the PPG sensor based on the analysis of the motion signal when motion of the patient is detected.

2. The system of claim 1, wherein the processor is configured to deactivate the at least one emitter of the PPG sensor in response to a determination that the motion signal exceeds a motion threshold for a period of time that exceeds a duration threshold.

3. The system of claim 1, wherein the processor is configured to deactivate the at least one emitter of the PPG sensor in response to a determination that the motion signal exceeds a motion degree threshold.

4. The system of claim 1, wherein the processor is configured to reactivate the at least one emitter in response to a determination that motion of the patient has ceased or in response to a determination that the at least one emitter has been deactivated for an amount of time that reaches a suppression threshold.

5. The system of claim 1, comprising a light drive coupled to the processor, wherein the light drive is configured to provide a drive signal to the at least one emitter to activate the at least one emitter, and wherein the processor is configured to control the light drive to control activation and deactivation of the at least one emitter.

6. The system of claim 1, comprising:

a power source configured to power the at least one emitter; and

a switch coupled to the power source and the at least one emitter, wherein the processor is configured to open the switch to deactivate the at least one emitter and to close the switch to reactivate the at least one emitter.

7. The system of claim 1, wherein the processor is configured to analyze the motion signal to determine a type of motion and to deactivate the at least one emitter of the PPG sensor based on the type of motion.

8. The system of claim 7, wherein the at least one emitter of the PPG sensor comprises a first light emitting diode (LED) and a second LED, and wherein the processor, in response to a determination that the type of motion is walking, is configured to:

calculate oxygen saturation and pulse rate based on the PPG signal, wherein the light detected by the detector to generate the PPG signal comprises light emitted from the first and second LEDs after interaction with the tissue; and

suppress processing of the PPG signal for a respiration rate calculation.

9. The system of claim 7, wherein the at least one emitter of the PPG sensor comprises a first light emitting diode (LED) and a second LED, and wherein processor, in response to a determination that the type of motion is tapping on the PPG sensor, is configured to:

deactivate the first LED of the PPG sensor, wherein the light detected by the detector to generate the PPG signal when the first LED is deactivated comprises light emitted from the second LED after interaction with the tissue;

calculate respiration rate based on the PPG signal; and

suppress processing of the PPG signal for an oxygen saturation calculation and a pulse rate calculation.

10. The system of claim 1, wherein the motion sensor is disposed in a housing of the PPG sensor.

11. The system of claim 1, comprising a patient-worn pulse oximeter having the processor and the PPG sensor, wherein the patient-worn pulse oximeter is configured to calculate physiological parameters of the patient based on the PPG signal, and wherein the motion sensor is disposed in a housing of the patient-worn pulse oximeter.

12. The system of claim 1, wherein the motion sensor is disposed in a patient-worn article configured to be secured to the patient.

13. The system of claim 1, wherein the motion sensor is disposed in a patient bed.

14. A patient monitor, comprising:

a memory encoding one or more processor-executable routines; and

a processor configured to access and execute the one or more processor-executable routines encoded by the memory, wherein the one or more processor-executable routines, when executed, cause the processor to;

receive a photoplethysmograph (PPG) signal from a PPG sensor configured to be secured to a patient;

receive a motion signal indicative of motion of the patient from a motion sensor;

detect patient motion in response to a determination that the motion signal exceeds a motion threshold; and

deactivate at least one emitter of the PPG sensor in response to a determination that a degree of the patient motion exceeds a motion degree threshold or a determination that a duration of the patient motion exceeds a motion duration threshold.

15. The patient monitor of claim 14, wherein the one or more processor-executable routines, when executed, cause the processor to:

determine a type of the patient motion; and

deactivate the at least one emitter of the PPG sensor based on the type of the patient motion.

16. The patient monitor of claim 15, wherein the type of the patient motion comprises tapping on the PPG sensor, and wherein the at least one emitter of the PPG sensor comprises a first light emitting diode (LED) and second LED, and wherein one or more processor-executable routines, when executed, cause the processor to:

deactivate the first LED of the PPG sensor in response to the determination that the degree of the patient motion exceeds the motion degree threshold or the determination that the duration of the patient motion exceeds the motion duration threshold; and

calculate respiration rate based on the PPG signal generated while the second LED is activated.

17. The patient monitor of claim 15, wherein the memory stores a plurality of suppression thresholds and each suppression threshold of the plurality of suppression thresholds is associated with one type of patient motion, and wherein the one or more processor-executable routines, when executed, cause the processor to:

select a suppression threshold from the plurality of suppression thresholds stored in the memory based on the type of the patient motion;

deactivate at least one emitter of the PPG sensor for a period of time; and

reactivate the at least one emitter of the PPG sensor when the period of time reaches the suppression threshold.

18. The patient monitor of claim 15, wherein the memory stores a plurality of motion profiles and each motion profile of the plurality of motion profiles is associated with one type of patient motion, and wherein the one or more processor-executable routines, when executed, cause the processor to:

compare the motion signal to one or more motion profiles of the plurality of motion profiles stored in the memory; and

determine a type of patient motion based on the comparison.

19. The patient monitor of claim 14, wherein the one or more processor-executable routines, when executed, cause the processor to open a switch disposed between a power source and the at least one emitter of the PPG sensor to deactivate the at least one emitter of the PPG sensor.

20. A method, comprising:

receiving, via a processor, a photoplethysmograph (PPG) signal from a PPG sensor configured to be secured to a patient;

receiving, via the processor, a motion signal indicative of motion of the patient from a motion sensor;

detecting, via the processor, patient motion in response to a determination that the motion signal exceeds a motion threshold; and

deactivating, via the processor, at least one emitter of the PPG sensor in response to a determination that a degree of the patient motion exceeds a motion degree threshold or a determination that a duration of the patient motion exceeds a motion duration threshold

21. The method of claim 20, comprising providing a drive signal, via a light drive coupled to the processor, to the at least one emitter to activate the at least one emitter, and wherein deactivating the at least one emitter comprises suppressing the drive signal to the at least one emitter.

22. The method of claim 20, comprising:

determining, via the processor, a type of the patient motion based on the motion signal; and

deactivating, via the processor, the at least one emitter based on the type of the patient motion.

23. The method of claim 20, comprising:

determining, via the processor, whether the patient motion has ceased; and

reactivating, via the processor, the at least one emitter in response to a determination that the patient motion has ceased.

24. The method of claim 23, comprising reactivating, via the processor, the at least one emitter in response to a determination that the patient motion has not ceased and a determination that the at least one emitter has been deactivated for a period of time that exceeds a suppression threshold.