INTERFERENCE DETECTOR FOR PATIENT MONITOR

• US 20150012231A1
• Filed: 06/05/2014
• Published: 01/08/2015
• Est. Priority Date: 07/24/2009
• Status: Active Grant

• Current Assignee: Masimo Corporation
• Original Assignee: Cercacor Laboratories
• Inventors: Poeze, Jeroen, Chen, Jesse, Paul, Mathew, Lamego, Marcelo, Kiani, Massi Joe E.
• Granted Patent: US 9,989,560 B2
• Time in Patent Office: Days
• US Class Current: 702/58
• CPC Class Codes: A61B 2560/0242 adapted to measure environmental factors, e.g. temperature, pollution
• CPC Class Codes: A61B 2560/0276 Determining malfunction
• CPC Class Codes: A61B 5/0015 characterised by features of the telemetry system
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7228 Signal modulation applied to the input signal sent to patient or subject; demodulation to recover the physiological signal modulation H03C
• CPC Class Codes: G01R 13/0281 using electro-optic elements
• CPC Class Codes: G01R 29/0814 Field measurements related to measuring influence on or from apparatus, components or humans EMC, EMI and similar testing in general G01R31/001, e.g. in ESD, EMI, EMC, EMP testing, measuring radiation leakage; detecting presence of micro- or radiowave emitters; dosimetry; testing shielding; measurements related to lightning

Abstract

A system is disclosed for detecting and calculating the level of ambient and/or environmental noise, such as electromagnetic interference generated by electric power lines, ambient lights, light dimmers, television or computer displays, power supplies or transformers, and medical equipment. In some embodiments, the system performs frequency analysis on the interference signal detected by light photodetectors and determines the power of the interference signal concentrated in the analyzed frequency bands. The worst-case interference level can be determined by selecting the maximum from the computed power values. In some embodiments, the determined interference signal power can be compared with the noise tolerance of a patient monitoring system configured to reliably and noninvasively detect physiological parameters of a user. The results of the comparison can be presented to the user audio-visually. In some embodiments, the system can be used to perform spot check measurements of electromagnetic interference.

Claims

1-20. -20. (canceled)

21. A noninvasive monitor configured to test a suitability of an environment for patient monitoring with a sensor including an optical radiation source and one or more detectors housed in a sensor housing, the sensor housing configured to position the optical radiation source and the one or more detectors proximate tissue of a patient, the noninvasive monitor comprising:

an input configured to receive from a sensor a first sensor signal responsive to light attenuated by tissue of a patient and a second sensor signal responsive to ambient electronic interference proximate the sensor; and

a hardware processor configured to;

process the first sensor signal to determine measurement values for one or more physiological parameters of the patient,

process the second sensor signal differently from the first sensor signal to determine a level of ambient electronic interference proximate the sensor,

determine at least one of an audio or visual indication of the level of ambient electronic interference, and

output the at least one of the audio or visual indication.

22. The noninvasive monitor of claim 21, wherein the hardware processor is configured to:

compare the level of ambient electronic interference to a threshold to determine a suitability of a testing environment for patient monitoring; and

vary the threshold according at least to the one or more physiological parameters monitored for the patient.

23. The noninvasive monitor of claim 21, wherein the hardware processor is configured to:

process the second sensor signal differently from the first sensor signal to determine levels of ambient electronic interference proximate the sensor at a plurality of frequencies; and

determine a likelihood of successful processing of the first sensor signal given the levels of ambient electronic interference proximate the sensor at the plurality of frequencies.

24. The noninvasive monitor of claim 23, wherein the levels of ambient electronic interference proximate the sensor at the plurality of frequencies comprise measures of energy or power of ambient electronic interference proximate the sensor at the plurality of frequencies.

25. The noninvasive monitor of claim 21, wherein the hardware processor is configured to set a modulation rate of an optical radiation source of the sensor based at least on the level of ambient electronic interference to reduce an impact of the level of ambient electronic interference on the first sensor signal.

26. The noninvasive monitor of claim 21, wherein the hardware processor is configured to output the visual indication so that the visual indication is shown relative to ranges of ambient electronic interference on a display.

27. The noninvasive monitor of claim 26, wherein the ranges of ambient electronic interference include a first range associated with a low severity of ambient electronic interference, a second range associated with a medium severity of ambient electronic interference, and a third range associated with a high severity of ambient electronic interference.

28. The noninvasive monitor of claim 21, wherein the input is configured to receive the first sensor signal at a different time from when the input receives the second sensor signal.

29. The noninvasive monitor of claim 21, wherein the hardware processor is configured to output the at least one of the audio or visual indication via a communication network to a device.

30. The noninvasive monitor of claim 21, wherein the second sensor signal is responsive to ambient electronic interference proximate the sensor after attenuation by the tissue of the patient.

31. A method of testing an environment to be suitable for patient monitoring with a sensor including an optical radiation source and one or more detectors housed in a sensor housing, the sensor housing configured to position the optical radiation source and the one or more detectors proximate tissue of a patient, the sensor configured to output a sensor signal responsive to optical radiation attenuated by the tissue of the patient, the method comprising:

receiving from a sensor, at an input, a first sensor signal responsive to light attenuated by tissue of a patient and a second sensor signal responsive to ambient electronic interference proximate the sensor;

electronically processing the first sensor signal to determine measurement values for one or more physiological parameters of the patient;

electronically processing the second sensor signal differently from the first sensor signal to determine a level of ambient electronic interference proximate the sensor;

determining at least one of an audio or visual indication of the level of ambient electronic interference; and

outputting the at least one of the audio or visual indication.

32. The method of claim 31, further comprising comparing the level of ambient electronic interference to a threshold to determine a suitability of a testing environment for patient monitoring and varying the threshold according at least to the one or more physiological parameters monitored for the patient.

33. The method of claim 31, wherein said electronically processing the second sensor signal comprises electronically processing the second sensor signal to determine levels of ambient electronic interference proximate the sensor at a plurality of frequencies, and further comprising determining a likelihood of successful processing of the first sensor signal given the levels of ambient electronic interference proximate the sensor at the plurality of frequencies.

34. The method of claim 33, wherein the levels of ambient electronic interference proximate the sensor at the plurality of frequencies comprise measures of energy or power of ambient electronic interference proximate the sensor at the plurality of frequencies.

35. The method of claim 31, further comprising setting a modulation rate of an optical radiation source of the sensor based at least on the level of ambient electronic interference to reduce an impact of the level of ambient electronic interference on the first sensor signal.

36. The method of claim 31, wherein said outputting comprises outputting the visual indication so that the visual indication is shown relative to ranges of ambient electronic interference on a display.

37. The method of claim 36, wherein the ranges of ambient electronic interference include a first range associated with a low severity of ambient electronic interference, a second range associated with a medium severity of ambient electronic interference, and a third range associated with a high severity of ambient electronic interference.

38. The method of claim 31, wherein said receiving comprises receiving the first sensor signal at a first time and receiving the second sensor signal at a second time different from the first time.

39. The method of claim 31, wherein said outputting comprises outputting the at least one of the audio or visual indication via a communication network to a device.

40. The method of claim 31, further comprising:

determining the level of ambient electronic interference at a first location; and

in response to determining that the first location is not a suitable testing environment for determining the measurement values, determining the level of ambient electronic interference at a second location different from the first location.