Abstract: Methods, systems and related apparatus are provided to enable an electronic device to operate an external sensor comprising one or more emitters for emitting electromagnetic radiation of two different wavelengths and a detector for generating a response signal based on received electromagnetic radiation of the two different wavelengths connectable to an audio interface by applying a harmonic driving signal to a first contact and a second contact of the audio interface for driving the emitters of the external sensor, receiving the response signal at a third contact of the audio interface, demodulating and demultiplexing the response signal into a first wavelength response signal and a second wavelength response signal, analyzing the first and second wavelength response signals to determine one or more vital signs, and outputting the determined one or more vital signs.

Abstract: Methods, systems and related apparatus are provided to enable an electronic device to operate an external sensor comprising one or more emitters for emitting electromagnetic radiation of two different wavelengths and a detector for generating a response signal based on received electromagnetic radiation of the two different wavelengths connectable to an audio interface by applying a harmonic driving signal to a first contact and a second contact of the audio interface for driving the emitters of the external sensor, receiving the response signal at a third contact of the audio interface, demodulating and demultiplexing the response signal into a first wavelength response signal and a second wavelength response signal, analyzing the first and second wavelength response signals to determine one or more vital signs, and outputting the determined one or more vital signs.

Abstract: Methods, systems and related apparatus are provided for controlling an electronic device to operate an external sensor connectable to an audio interface of the electronic device by applying a first harmonic driving signal to a first contact and a second harmonic driving signal to a second contact of the audio interface for driving the external sensor, receiving a response signal at a third contact of the audio interface, adjusting at least one of the first and second harmonic driving signals, determining one or more physiological parameters based on characteristics of the first and second harmonic driving signals and the response signal, and outputting the determined one or more physiological parameters.