Wearable Sensing in Low-Field (0.55 T) MRI Environment

Abstract

Wearable sensors in the magnetic resonance imaging (MRI) environment enable the use of wearable devices to monitor vital signs, such as heart rate, respiration rate, blood pressure, temperature, and biochemical markers, during an MRI scan. Here, we demonstrate the efficacy of Bluetooth Low Energy (BLE)-enabled optical photoplethysmogram (PPG) sensors at a low-field MRI strength of 0.55 T. We evaluate the noise in a wearable device caused by eddy currents from the rapidly switching MRI gradients, as well as the MRI noise and artifacts introduced by the BLE wearable into the MR receiver. Our results show that a custom-made BLE PPG sensor can operate effectively during 0.55 T MRI scanning, providing precise (within 20 ms) wireless monitoring of PPG with no observable effect on either the sensor signal or image quality. These results are encouraging for future wearable sensing in the MRI environment.