Systems and methods for sensor calibration in photoplethysmography

A wireless photoplethysmography system, comprising:

• a monitor comprising a monitor processor;
• a wireless photoplethysmography sensor, comprising:
• a sensor body, comprising:
• an emitter configured to emit light;
• a memory storing a plurality of calibration coefficients or calibration curves each corresponding to respective wavelengths of light that may be emitted by the emitter;
• a calibration circuit coupled to an electrical input of the emitter to measure a first voltage present at the electrical input and coupled to an electrical output of the emitter to measure a second voltage present at the electrical output;
• a sensor processor configured to determine a voltage difference between the first voltage and the second voltage when a current is passed through the emitter, and to select an appropriate calibration coefficient or calibration curve for the photoplethysmography sensor from the plurality of calibration coefficients or calibration curves stored on the memory based on the voltage difference;
• and
• a wireless transmitter configured to wirelessly transmit the appropriate calibration coefficient or calibration curve to the monitor, wherein the appropriate calibration coefficient or calibration curve enables the monitor processor to calculate a physiological parameter.

A method of operating a wireless photoplethysmography system, comprising:

• passing a first current through an emitter positioned within a sensor body of a wireless photoplethysmography sensor to cause the emitter to emit light;
• measuring, using a calibration circuit positioned within the sensor body, a first voltage present at an electrical input of the emitter and a second voltage present at the electrical output of the emitter;
• determining, using a processor positioned within the sensor body, a voltage difference between the first voltage and the second voltage when the first current is passed through emitter;
• selecting, using the processor, an appropriate calibration coefficient or calibration curve for the wireless photoplethysmography sensor from a plurality of calibration coefficients or calibration curves stored on a memory positioned within the sensor body based on the voltage difference, wherein each of the plurality of calibration coefficients or calibration curves corresponds to respective wavelengths of light that may be emitted by the emitter;
• and
• transmitting, using a wireless transceiver, the appropriate calibration coefficient or calibration curve to a monitor to enable the monitor to calculate a physiological parameter.