Method and Apparatus with Multi-Wavelength Optical Instruments for Blood Pressure Measurement

An apparatus for measuring blood pressure of a subject, comprising:

• a form factor configured to place the apparatus on a surface of the subject in a position that is proximate to blood vessels identified for blood pressure measurements;
• a plurality of LEDs directing a plurality of wavelengths of light from the apparatus toward the identified blood vessels;
• a plurality of photodetectors generating a plurality of respective photoplethysmography (PPG) waveforms and corresponding PPG data in response to each of the wavelengths of light, and the photodetectors being configured to transmit, for each of the wavelengths of light, wavelength data and the corresponding PPG data from the apparatus to a computer comprising a processor in communication with computer memory storing the wavelength data and the PPG data in a feature vector;
• software implemented by the computer to perform steps comprising:
• extracting feature values from the feature vector;
• calculating feature ratios of selected pairs of feature values that each comprise a corresponding PPG data value for a respective wavelength data value;
• and
• using the feature ratios as inputs in a machine learning model to predict systolic blood pressure (SBP), diastolic blood pressure (DBP), or mean arterial blood pressure (MAP) with the feature ratios.