Patent ID: 8958859
Filing Date: 2015-02-17
Classification: A61B

Abstract:
1. A method for controlling an electronic device to operate an external sensor to obtain one or more vital signs, the electronic device having an audio interface comprising a plurality of contacts, the external sensor connectable to the audio interface and 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, the method comprising: applying a harmonic driving signal to a first contact and a second contact of the audio interface for driving the one or more emitters of the external sensor, the harmonic driving signal comprising a first sinusoidal driving signal applied to the first contact of the audio interface and a second sinusoidal driving signal to the second contact of the audio interface, the first and second sinusoidal signals being substantially 180 degrees out of phase; 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.