Contactless Vital Sign Monitoring of Macaques in the MRI Room via RF Sensing

Subgenual deep brain stimulation (DBS) is an experimental treatment for treatment-resistant depression (TRD). It involves implanting electrodes in the subgenual cingulate gyrus (SCG) of the brain.

Patients who receive subgenual DBS report acute effects, such as sudden calmness or lightness, disappearance of the void, sense of heightened awareness, increased interest, and connectedness.

To understand the physiological and behavioral effects induced by subgenual DBS and to examine emotional state in animals, several key observations can be made including:

• Eye gaze position and pupil size of the animal (via eye-tracking system)
• Facial and body movements (video and deep learning model)
• Heart and respiratory rate

While the first two elements can be reliably measured, measuring vital signs remains as a challenging task due to invasive implants or tedious behavioral training, such as training for respiratory belt that needs to be wrapped around an awake animal.

To solve this problem, we are working on implementing a novel radar solution that can record heart rate and respiratory rate from distance when an animal is in the MRI scanner. Radars can detect subtle radial motions in an observed scene (which is our animal in the scanner) with high temporal and spatial precision in a contactless fashion. Our solution consists of several signal processing steps including clutter removal, range-angle finding, spatial and bandpass filtering, random body movement correction and time frequency analysis of the received RF signal.