Physiological sensors with combined signal outputs

A method of processing a plurality of voltage signals received from a plurality of sensing electrodes of a physiological sensor, the method comprising:

• receiving, at a signal combining chip, a plurality of voltage signals that are measured by the plurality of sensing electrodes, wherein each voltage signal of the plurality of voltage signals is measured by a corresponding sensing electrode of the plurality of sensing electrodes;
• selecting, with a scan controller associated with the signal combining chip, a set of voltage signals from the plurality of voltage signals;
• generating, using a waveform generator in the signal combining chip, a set of modulation signals corresponding to the selected set of voltage signals;
• applying each modulation signal of the set of modulation signals to a corresponding selected voltage signal to form a corresponding encoded voltage signal of a set of encoded voltage signals;
• superimposing the set of encoded voltage signals, using a summing circuit, to form a combined voltage signal;
• outputting, at an output channel of the signal combining chip, the combined voltage signal
• receiving, through a receiving channel at a signal processing chip communicably coupled to the signal combining chip, the combined voltage signal;
• digitizing, using an analog-to-digital converter at the signal processing chip, the combined voltage signal to generate a digital combined signal;
• and
• demodulating the digital combined signal to generate a corresponding digital signal for each of the plurality of voltage signals received from the plurality of sensing electrodes of the physiological sensor.

A device for measuring voltage signals comprising:

• a physiological sensor comprising a plurality of sensing electrodes;
• and
• a signal combining chip comprising:
• a plurality of input channels configured to receive a plurality of voltage signals from the plurality of sensing electrodes, wherein each input channel of the plurality of input channels is configured to receive a corresponding voltage signal of the plurality of voltage signals from a corresponding sensing electrode of the plurality of sensing electrodes;
• a waveform generator configured to generate a set of modulation signals, wherein each of the set of modulation signals is applied to a corresponding voltage signal of the plurality of voltage signals to generate a corresponding encoded voltage signal of a set of encoded voltage signals;
• and
• a summing circuit configured to superimpose the set of encoded voltage signals to form a combined voltage signal;
• a digital interface driver configured to receive one or more control signals through a control channel;
• and
• an output channel configured to output the combined voltage signal.