System for adjusting power employed by a medical device

• US 20070038049A1
• Filed: 07/07/2006
• Published: 02/15/2007
• Est. Priority Date: 07/08/2005
• Status: Active Grant

• Current Assignee: Dragerwerk AG & Company KGaA (FPS Vermögensverwaltung GmbH)
• Original Assignee: Draeger Medical Systems Incorporated (Dragerwerk AG)
• Inventors: Huang, Johnnie
• Granted Patent: US 8,116,837 B2
• Time in Patent Office: Days
• US Class Current: 600/323
• CPC Class Codes: A61B 2560/0209 adapted for power saving
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/7257 using Fourier transforms

Abstract

A system for adjusting power employed by a medical device incorporating light emitting devices and being used for measuring patient medical parameters, includes a plurality of light emitting devices. A power unit is coupled to the light emitting devices and powers the light emitting devices responsive to respective control signals which determine power to be applied to the light emitting devices. A control unit for provides the control signals and is coupled to the power unit. The control signals intermittently turn off at least one of the plurality of light emitting devices in a power save mode in response to a determination that a patient medical parameter value measured by the medical device, using an active light emitting device of the plurality of light emitting devices, is at a safe level.

Claims

1. A system for adjusting power employed by a medical device incorporating light emitting devices and being used for measuring patient medical parameters, comprising:

a plurality of light emitting devices;

a power unit coupled to said light emitting devices for powering said light emitting devices responsive to respective control signals for determining power applied to said light emitting devices; and

a control unit for providing said control signals and being coupled to the power unit, said control signals intermittently turning off at least one of said plurality of light emitting devices in a power save mode in response to a determination that a patient medical parameter value measured by said medical device, using an active light emitting device of said plurality of light emitting devices, is at a safe level.

2. The system according to claim 1, wherein said control unit determines a patient medical parameter value comprising a blood oxygen saturation representative value is at said safe level by being above a predetermined threshold.

3. The system according to claim 2, wherein said control unit determines a patient medical parameter value comprising a pulse rate is at said safe level by being within a predetermined range.

4. The system according to claim 1, wherein said patient medical parameter comprises at least one of:

a blood oxygen saturation representative parameter;

a change in a blood oxygen saturation representative parameter;

a rate-of-change of a blood oxygen saturation representative parameter;

a pulse rate;

a change in pulse rate;

patient temperature;

arterial blood pressure;

a hematocrit level; and

a cardiac index.

5. A system for adjusting power employed by a medical device incorporating light emitting devices and being used for measuring patient medical parameters, comprising:

a plurality of light emitting devices;

a power unit coupled to said light emitting devices for powering said light emitting devices and responsive to respective control signals for determining power applied to said light emitting devices; and

a control unit for providing said control signals and being coupled to the power unit, said control signals intermittently turning off at least first and second different light emitting devices of said plurality of light emitting devices in a power save mode in response to a determination that a patient medical parameter value measured by said medical device, using an active light emitting device of said plurality of light emitting devices, is at a safe level;

wherein;

said medical device stores a parameter value obtained using an active first light emitting device prior to turning off said active light emitting device.

6. The system according to claim 5, wherein said control unit uses said stored parameter value obtained using said first light emitting device together with a parameter value obtained using an active second light emitting device to determine said patient medical parameter value measured by said medical device is at a safe level.

7. The system according to claim 5, further comprising:

a data processor employing a plurality of different processing functions for processing data derived using said plurality of light emitting devices in determining said patient medical parameter value measured by said medical device;

wherein;

said control unit provides a control signal for turning off at least one processing function of said plurality of processing functions in said power save mode in response to a sensitivity determination, said sensitivity determination being used to turn off a function having least effect in said determination of said patient medical parameter value measured by said medical device.

8. The system according to claim 7, wherein said control unit provides control signals for progressively turning off processing functions of said plurality of processing functions in said power save mode in response to sensitivity determinations.

9. The system according to claim 7, wherein

a subset of the plurality of processing functions operates in the frequency domain;

the system further comprises a fast Fourier transform (FFT) processing function, for transforming a set of time domain input samples, representing respective signals from said plurality of light emitting devices, into a corresponding set of frequency domain samples; and

said control unit provides control signals for reducing the processing required to produce said frequency domain samples in said power save mode.

10. The system according to claim 9 wherein the number of samples in the set of time domain samples is reduced in said power save mode.

11. The system according to claim 9 wherein the rate at which successive sets of time domain samples are transformed into corresponding sets of frequency domain output samples is reduced in said power save mode.

12. The system according to claim 5, wherein

said control unit provides a control signal for turning off said at least one of said plurality of light emitting devices in a power save mode for a user configurable predetermined time duration and monitors a patient medical parameter that is measured without using said at least one of said plurality of light emitting devices;

and

in response to a determination said monitored patient medical parameter value is outside a predetermined range, said control unit terminates said power save mode and turns on said at least one of said plurality of light emitting devices.

13. A system for adjusting power employed by a medical device incorporating light emitting devices and being used for measuring patient medical parameters, comprising:

a light emitting device;

a power unit coupled to said light emitting device for powering said light emitting device and responsive to a control signal for determining power applied to said light emitting device; and

a control unit for;

providing said control signal and being coupled to the power unit, said control signal turning off said light emitting device in a power save mode for a predetermined time duration,

monitoring a patient medical parameter that is measured without using said light emitting device, and

in response to a determination said monitored patient medical parameter value is outside a predetermined range, terminating said power save mode and turning on said light emitting device.

14. The system according the claim 13, wherein said control unit provides a control signal turning off operation of medical device functions unused in deriving said patient medical parameter that is measured without using said light emitting device.

15. The system according to claim 13, further comprising:

a data processor employing a plurality of different processing functions for processing data derived using said light emitting device in determining a patient medical parameter value measured by said medical device;

wherein;

said control unit provides a control signal for turning off at least one processing function of said plurality of processing functions in a power save mode in response to a sensitivity determination, said sensitivity determination being used to turn off a function having least effect in said determination of said patient medical parameter value measured by said medical device.

16. The system according to claim 13, wherein:

said monitored patient medical parameter value comprises at least one of;

a heart rate related parameter value;

a rate-of-change of a blood oxygen representative parameter;

patient temperature;

arterial blood pressure;

a hematocrit level, and

a cardiac index.

17. The system according to claim 13, wherein said predetermined time duration is user configurable.

18. The system according to claim 13, wherein said predetermined time duration is adjustable by said system.

19. A system for adjusting power employed by a medical device incorporating light emitting devices and being used for measuring patient medical parameters, comprising:

a light emitting device;

a power unit coupled to said light emitting device for powering said light emitting device and responsive to a control signal for determining power applied to said light emitting device; and

a control unit for;

providing said control signal and being coupled to the power unit, said control signal turning off said light emitting device in a power save mode for a predetermined time duration,

providing a control signal for turning off processing of data occurring in deriving a patient medical parameter using said light emitting device in said power save mode,

monitoring a patient medical parameter that is measured without using said light emitting device, and

in response to a determination said monitored patient medical parameter value is outside a predetermined range, terminating said power save mode and turning on said light emitting device.

20. The system according the claim 19, wherein said patient medical parameter derived using said light emitting device comprises at least one of, (a) a blood oxygen saturation representative parameter and (b) a pulse rate.

21. A system for adjusting power employed by a medical device incorporating light emitting devices and being used for measuring patient medical parameters, comprising:

a light emitting device;

a power unit coupled to said light emitting device for powering said light emitting device and responsive to a first control signal for determining power applied to said light emitting device;

a data processor employing a plurality of different processing functions for processing data derived using said light emitting device in determining a patient medical parameter value measured by said medical device; and

a control unit for providing said first control signal and a second control signal for turning off at least one processing function of said plurality of processing functions in a power save mode in response to a predetermined function disablement procedure.

22. The system according to claim 21, wherein said predetermined function disablement procedure turns off said at least one processing function in response to a sensitivity determination, said sensitivity determination being used to turn off a function having least effect in said determination of said patient medical parameter value measured by said medical device.

23. The system according to claim 22, wherein said control unit provides control signals for progressively turning off processing functions of said plurality of processing functions in said power save mode in response to sensitivity determinations.

24. The system according to claim 21, further comprising:

a plurality of light emitting devices;

wherein;

said power unit is coupled to said light emitting devices for powering said light emitting devices and responsive to respective control signals for determining power applied to said light emitting devices; and

said control unit provides control signals for intermittently turning off said plurality of light emitting devices in a power save mode in response to a determination a patient medical parameter value measured by said medical device, using an active light emitting device of said plurality of light emitting devices, is at a safe level.

25. The system according to claim 21, wherein

said first control signal turns off said light emitting device in a power save mode for a user configurable predetermined time duration;

and

said control unit monitors a patient medical parameter that is measured without using said light emitting device and in response to a determination said monitored patient medical parameter value is outside a predetermined range, terminates said power save mode and turns on said light emitting device.

28. The system according the claim 24, wherein said control unit provides a control signal turning off at least one processing function of a plurality of processing functions in response to a sensitivity determination, said sensitivity determination being used to turn of a function having least effect in said determination of said patient medical parameter value measured by said medical device.

26. A system for adjusting power employed by a medical device incorporating light emitting devices and being used for measuring patient medical parameters, comprising:

a light emitting device used in monitoring a first parameter comprising a blood oxygen related patient parameter;

a power unit coupled to said light emitting device for powering said light emitting device and responsive to a control signal for determining power applied to said light emitting device; and

a control unit for

providing said control signal and being coupled to the power unit, said control signal initiating switching off said light emitting device for a predetermined time duration in a power save mode, and

in response to a determination that a monitored second parameter has a value outside a predetermined range, said monitored second parameter comprising a patient medical parameter that is measured without using said light emitting device, switching on said light emitting device.

27. A system for adjusting power employed by a medical device incorporating light emitting devices and being used for measuring patient medical parameters, comprising:

a light emitting device;

a power unit coupled to said light emitting device for powering said light emitting device and responsive to a control signal for determining power applied to said light emitting device and for turning off processing of data occurring in deriving a patient medical parameter using said light emitting device; and

a control unit for,

providing said control signal, and

monitoring a patient medical parameter that is measured without using said light emitting device, and

in response to a determination said monitored patient medical parameter value is outside a predetermined range, turning on said light emitting device.