BR and HR estimation by applying frequency analysis on the phase of mmWave signals

Invention Summary:

Existing real-time cardiovascular disease monitoring methods are mostly based on wearable solutions, such as finger pulse meters, smart watches, electro-cardiograms (ECGs). These methods are intrusive, costly, require direct contact with the patient and can only obtain one single vital sign information at a time. To overcome these problems, devices were developed to use radio frequency (RF) signals for contact-less vital sign monitoring. However, these devices operate at fixed frequencies, and thus have limited ability to disentangle echo signals from targets at different ranges. Such limitation precludes their use in health monitoring of multiple individuals.

Rutgers researchers have designed and implemented a time- division multiplexing (TDM) phased-MIMO radar sensing system that allows high precision vital sign monitoring of multiple subjects. By utilizing frequency-modulated continuous-waveform (FMCW) techniques, the system can separate individuals at different radial distances. The sensing system can steer a signal beam towards the desired directions with a micro‐second delay and the steerable beam enables capturing the vital signs of multiple individuals at the same radial distance to the radar. A virtual array with larger aperture can be constructed providing a higher angular resolution. Under two-subject scenario, this system can achieve more than 98.06% accuracy for breathing rate (BR) and more than 82.89% accuracy for heart rate (HR) estimation at a subject‐to‐radar distance of 1.6 m when the targets are facing the radar. The minimal subject-to-subject distance required is about 0.3 m between the two subjects.

Related Technology: Non-contact Vital Sign and Motion Detection Sensor


  • Non-intrusive, contact-free
  • Continuous & remote monitoring
  • This technology can track the breathing rate and heart rate of two closely seated people
  • Simultaneous monitoring of multiple individuals

Market Applications:

  • Sleep apnea detection
  • Surveillance of multiple people

Intellectual Property & Development Status: 

Provisional patent application filed, patent pending. Available for licensing and/or search collaboration. Please contact


Patent Information: