Patient monitor alarm speaker analyzer

1. A patient monitor that measures a physiological parameter of a patient, the patient monitor comprising:

a microphone;

a loudspeaker;

at least one physiological sensor; and

a hardware processor that:

receives a signal obtained from the at least one physiological sensor;

determines a measurement value for the physiological parameter of the patient from the signal;

determines that the measurement value triggers an alarm;

outputs the alarm to the loudspeaker;

subsequent to outputting the alarm to the loudspeaker, records a first microphone signal from the microphone;

determines that the first microphone signal level does not sufficiently match an expected alarm signal level;

responsive to the determination that the first microphone signal level does not sufficiently match the expected alarm signal level, determines a maximum volume of the loudspeaker has not been reached;

responsive to the determination that the maximum volume of the loudspeaker has not been reached, increases a volume of the loudspeaker;

records a second microphone signal from the microphone;

determines, subsequent to receiving the second microphone signal, that the second microphone signal also does not sufficiently match the expected alarm signal level;

responsive to the determination that the second microphone signal also does not sufficiently match the expected alarm signal level, determines the maximum volume of the loudspeaker has been reached; and

responsive to the determination that the maximum volume of the loudspeaker has been reached, outputs an error indication regarding the loudspeaker.

2. The patient monitor of claim 1 , wherein the error indication regarding the loudspeaker indicates the loudspeaker may be obstructed.

3. The patient monitor of claim 1 , wherein the error indication regarding the loudspeaker indicates the loudspeaker may be malfunctioning.

4. The patient monitor of claim 1 , wherein the hardware processor outputs the error indication as a buzzer output.

5. The patient monitor of claim 1 , wherein the hardware processor outputs the error indication as a textual indication.

6. The patient monitor of any of claim 1 , wherein the hardware processor outputs the error indication as an icon on a display.

7. The patient monitor of any of claim 1 , wherein the hardware processor outputs the error indication as a message to a remote server.

8. A patient monitor that measures a physiological parameter of a patient by emitting multiple wavelengths of light into body tissue of the patient, the patient monitor comprising:

a driver circuit that drives one or more emitters at the multiple wavelengths of light;

a front end processing circuit that: (1) receives a signal from a detector responsive to the multiple wavelengths of light from said emitters attenuated by body tissue of the patient, and (2) outputs a conditioned signal; and

a hardware processor that:

determines a measurement value for the physiological parameter of the patient from the conditioned signal;

determines that the measurement value triggers an alarm;

causes a loudspeaker to output an audio alarm responsive to the determination that the measurement value triggers an alarm;

receives a microphone input signal from a microphone;

detects the audio alarm in the microphone input signal;

determines that the detected audio alarm is below a threshold magnitude and that the loudspeaker may therefore be obstructed or partially obstructed;

responsive to the determination that the detected audio alarm is below the threshold magnitude and that the loudspeaker may therefore be obstructed or partially obstructed, determines a maximum volume of the loudspeaker has not been reached;

responsive to the determination that the maximum volume has not been reached, drives the loudspeaker at the maximum volume;

subsequent to driving the loudspeaker at the maximum volume, detects that the audio alarm is still below the threshold magnitude and that the loudspeaker therefore may be obstructed or partially obstructed;

responsive to the detection that the audio alarm is still below the threshold magnitude and that the loudspeaker may therefore be obstructed or partially obstructed, determines the maximum volume of the loudspeaker has been reached; and

responsive to the determination that the maximum volume of the loudspeaker has been reached, outputs an indication that the loudspeaker is obstructed or partially obstructed.

9. The patient monitor of claim 8 , wherein the hardware processor detects the audio alarm by performing frequency domain analysis of the microphone input signal.

10. The patient monitor of claim 8 , wherein the hardware processor detects the audio alarm by correlating the microphone input signal with the audio alarm output to the loudspeaker.

11. The patient monitor of claim 8 , wherein the hardware processor outputs the indication by outputting a second alarm to a buzzer.

12. The patient monitor of claim 8 , wherein the hardware processor outputs the indication as a message to a remote server for forwarding the message to a clinician or technician.

13. A patient monitoring method comprising:

under control of a patient monitor comprising a hardware processor,

determining a measurement value for a physiological parameter of a patient based on a signal received from a sensor coupled with the patient;

determining that the measurement value triggers an alarm;

outputting the alarm to a loudspeaker;

while outputting the alarm to the loudspeaker, receiving a microphone signal from a microphone;

analyzing the microphone signal to attempt to identify the alarm output by the loudspeaker;

determining that the microphone signal does not sufficiently match an expected alarm signal;

responsive to the determination that the microphone signal does not sufficiently match the expected alarm signal, determining that a maximum volume of the loudspeaker has not been reached;

responsive to the determination that the maximum volume of the loudspeaker has not been reached, driving the loudspeaker at the maximum volume;

determining, subsequent to driving the loudspeaker at the maximum volume, that the microphone signal still does not sufficiently match the expected alarm signal;

responsive to the determination that the microphone signal still does not sufficiently match the expected alarm signal, determining that the maximum volume of the loudspeaker has been reached; and

responsive to the determination that the maximum volume of the loudspeaker has been reached, outputting an error indication regarding the loudspeaker.

14. The patient monitoring method of claim 13 , wherein the error indication regarding the loudspeaker comprises an indication that the loudspeaker may be obstructed.

15. The patient monitoring method of claim 13 , wherein the error indication regarding the loudspeaker comprises an indication that the loudspeaker may be malfunctioning.

16. The patient monitoring method of claim 13 , wherein said outputting of the error indication regarding the loudspeaker comprises sending a message to a remote server.

17. The patient monitoring method of claim 13 , wherein said analyzing the microphone signal comprises performing frequency domain analysis and time domain analysis.

18. The patient monitoring method of claim 17 , wherein said frequency domain analysis comprises detecting harmonic tones in a frequency spectrum.

19. The patient monitoring method of claim 17 , wherein said time domain analysis comprises performing an autocorrelation or cross-correlation.

20. The patient monitoring method of claim 19 , further comprising comparing an output of the autocorrelation or cross-correlation with a threshold.