METHODS AND SYSTEMS FOR POWER OPTIMIZATION IN A MEDICAL DEVICE

• US 20130324855A1
• Filed: 05/31/2012
• Published: 12/05/2013
• Est. Priority Date: 05/31/2012
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Nellcor Puritan Bennett LLC (Medtronic Plc)
• Inventors: Lisogurski, Daniel, Baker, Clark R. Jr.
• Granted Patent: US 9,241,643 B2
• Time in Patent Office: Days
• US Class Current: 600/476
• CPC Class Codes: A61B 2560/0209 adapted for power saving
• CPC Class Codes: A61B 5/0095 by applying light and detecting acoustic waves, i.e. photoacoustic measurements
• 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 5/0261 using optical means, e.g. infrared light
• CPC Class Codes: A61B 5/0295 using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/7225 Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F
• CPC Class Codes: A61B 5/7292 Prospective gating, i.e. predicting the occurrence of a physiological event for use as a synchronisation signal
• CPC Class Codes: A61B 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B

Abstract

A physiological monitoring system may use photonic signals to determine physiological parameters. The system may vary parameters of a light drive signal used to generate the photonic signal from a light source such that power consumption is reduced or optimized. Parameters may include light intensity, firing rate, duty cycle, other suitable parameters, or any combination thereof. In some embodiments, the system may use information from a first light source to generate a light drive signal for a second light source. In some embodiments, the system may vary parameters in a way substantially synchronous with physiological pulses, for example, cardiac pulses. In some embodiments, the system may vary parameters in response to an external trigger.

Claims

1. A method of operating a physiological monitor, the method comprising:

generating a light drive signal for activating a light source to emit a photonic signal, wherein at least one parameter of the light drive signal is configured to vary substantially synchronously with physiological pulses of a subject and wherein the at least one parameter is at least one of light intensity, light source firing rate, and duty cycle.

2. The method of claim 1, wherein the at least one parameter of the light drive signal comprises the light intensity.

3. The method of claim 1, wherein the at least one parameter of the light drive signal comprises the light source firing rate.

4. The method of claim 1, further comprising:

receiving a light signal attenuated by the subject; and

sampling the light signal at a sampling rate, wherein the sampling rate varies substantially synchronously with the physiological pulses of the subject.

5. The method of claim 1, wherein the at least one parameter of the light drive signal comprises the duty cycle.

6. The method of claim 1, wherein generating the light drive signal comprises correlating a cardiac cycle modulation with periods of interest in the cardiac cycle.

7. The method of claim 1, wherein the physiological pulses of the subject are cardiac pulses.

8. The method of claim 1, wherein the physiological pulses of the subject are respiratory pulses.

9. The method of claim 1, wherein the light source comprises at least two emitters and wherein the light drive signal is configured to activate the at least two emitters.

10. The method of claim 1, further comprising:

receiving a light signal attenuated by the subject, wherein the light signal comprises a component corresponding to the photonic signal; and

analyzing the component of the light signal, wherein the light drive signal is generated based on the analysis of the component.

11. The method of claim 9, wherein analyzing the component of the light signal comprises determining information related to the physiological pulses of the subject.

12. The method of claim 1, further comprising receiving an external trigger, wherein the light drive signal is generated based on the external trigger.

13. The method of claim 1, further comprising:

receiving a light signal attenuated by the subject, wherein the light signal comprises a component corresponding to the photonic signal; and

determining a physiological parameter of the subject based on the component of the light signal.

14. A physiological monitoring system, comprising processing equipment configured to:

generate a light drive signal for activating a light source to emit a photonic signal, wherein at least one parameter of the light drive signal is configured to vary substantially synchronously with physiological pulses of a subject and wherein the at least one parameter is at least one of light intensity, light source firing rate, and duty cycle.

15. The system of claim 14, wherein the at least one parameter of the light drive signal comprises the light intensity.

16. The system of claim 14, wherein the at least one parameter of the light drive signal comprises the light source firing rate.

17. The system of claim 14, wherein the processing equipment is further configured to:

receive a light signal attenuated by the subject; and

sample the light signal at a sampling rate, wherein the sampling rate varies substantially synchronously with the physiological pulses of the subject.

18. The system of claim 14, wherein the at least one parameter of the light drive signal comprises the duty cycle.

19. The system of claim 14, wherein the light drive signal comprises a cardiac cycle modulation correlated with periods of interest in the cardiac cycle.

20. The system of claim 14, wherein the physiological pulses of the subject are cardiac pulses.

21. The system of claim 14, wherein the physiological pulses of the subject are respiratory pulses.

22. The system of claim 14, further comprising the light source coupled to the processing equipment, wherein the light source comprises at least two emitters and wherein the light drive signal is configured to activate the at least two emitters.

23. The system of claim 14, wherein the processing equipment is further configured to:

receive a light signal attenuated by the subject, wherein the light signal comprises a component corresponding to the photonic signal; and

analyze the component of the light signal, wherein the light drive signal is generated based on the analysis of the component.

24. The system of claim 23, wherein the processing equipment is further configured to analyze the component of the light signal to determine information related to the physiological pulses of the subject.

25. The system of claim 14, wherein the processing equipment is further configured to receive an external trigger, wherein the light drive signal is generated based on the external trigger.

26. The system of claim 14, wherein the processing equipment is further configured to:

receive a light signal attenuated by the subject, wherein the light signal comprises a component corresponding to the photonic signal; and

determine a physiological parameter of the subject based on the component of the light signal.