Heart rate detection architecture

A heart rate detection device, configured to receive a photoplethysmography (PPG) raw data from a PPG detector and a microelectromechanical systems (MEMS) raw data from a MEMS accelerometer, the heart rate detection device comprising:

• a PPG hardware module configured to receive the PPG raw data, the PPG hardware module comprising:
• a first bandpass filter configured to filter the PPG raw data;
• a first conversion module configured to convert the filtered PPG raw data to PPG spectrum values and PPG frequency index;
• and
• a first peak extraction module configured to search PPG peak spectrum values among the PPG spectrum values, and output the PPG peak spectrum values and the PPG frequency index;
• a MEMS hardware module configured to receive the MEMS raw data, the MEMS hardware module comprising:
• a second bandpass filter configured to filter the MEMS raw data;
• a second conversion module configured to convert the filtered MEMS raw data to MEMS spectrum values and MEMS frequency index;
• and
• a second peak extraction module configured to search a MEMS peak spectrum value among the MEMS spectrum values, and output the MEMS peak spectrum values and the MEMS frequency index;
• and
• a microcontroller unit (MCU), electrically coupled to the PPG hardware module and the MEMS hardware module, and configured to estimate a heart rate according to the PPG peak spectrum values, the PPG frequency index, the MEMS peak spectrum values and the MEMS frequency index by
• determining a reference index according to a frequency index corresponding to the MEMS peak spectrum value in the MEMS spectrum values,
• determining a denoising range according to the reference index,
• removing the PPG spectrum values in the PPG spectrum values corresponding to the denoising range to generate denoised PPG frequency data, and
• calculating the heart rate according to a PPG peak spectrum value of the denoised PPG frequency data,
• wherein the PPG hardware module outputs the PPG peak spectrum values as well as the PPG frequency index and the MEMS hardware module outputs the MEMS peak spectrum value as well as the MEMS frequency index without MCU operation to share loading of the MCU, and
• wherein the estimated heart rate is configured to be shown on a display.