Processing of electrophysiological signals

A system comprising:

• a processor;
• and
• a non-transitory computer readable medium coupled to the processor, the computer readable medium comprising instructions that, when executed on the processor, cause the processor to:
• detect peaks and valleys in photoplethysmography (PPG) signal;
• segment the PPG signal to provide a first time series of PPG waveforms located between two subsequent valleys in the PPG signal;
• apply pattern recognition to the first time series with respect to a reference PPG waveform pattern produced based on a mathematical model of the PPG signal by assigning a recognition score to the waveforms in the first time series, wherein the reference PPG waveform pattern is produced with a reaction-diffusion model, with diastolic and systolic phases of a heart coupled with the reaction and diffusion properties of the reaction-diffusion model, and wherein the instructions to apply the pattern recognition comprises instructions to apply cross-correlation analysis between the waveforms in the first time series and the reference PPG waveform pattern;
• retain the waveforms in the first time series having a recognition score higher or equal to a recognition threshold;
• and
• discard the waveforms in the first time series having a recognition score lower than the recognition threshold to produce a resulting PPG signal.

A system comprising:

• a processor;
• and
• a non-transitory computer readable medium coupled to the processor, the computer readable medium comprising instructions that, when executed on the processor, cause the processor to:
• receive a photoplethysmography (PPG) signal collected by a PPG sensing apparatus;
• detect peaks and valleys in the PPG signal;
• segment the PPG signal to provide a first time series of PPG waveforms located between two subsequent valleys in the PPG signal;
• produce a reference PPG waveform pattern based on a mathematical model of the PPG signal, the reference PPG waveform pattern being produced with a reaction-diffusion model, with diastolic and systolic phases of a heart coupled with the reaction and diffusion properties of the reaction-diffusion model;
• apply pattern recognition to the first time series with respect to the reference PPG waveform pattern by assigning a recognition score to the waveforms in the first time series, wherein applying the pattern recognition comprises applying cross-correlation analysis between the waveforms in the first time series and the reference PPG waveform pattern;
• and
• based on the pattern recognition, produce a resulting PPG signal.