Respiratory and cardiac rates monitoring during MR examination by a sensorized smart textile

Wearable sensorized smart textile are gaining interests in medicine for monitoring physiological parameters. Moreover, sensing solutions based on fiber optic technologies have shown promising results for applications in Magnetic Resonance (MR) environment. The aim of the present study was to evaluate the functionality of an MR-compatible smart textile based on six fiber Bragg grating (FBG) sensors inside the MR environment for the monitoring of both respiratory and cardiac activities during apnea and quiet breathing stages. The proposed textile was tested on two healthy volunteers undergoing 1.5 Tesla MR examination. By analyzing the raw data collected by the six FBGs, respiratory parameters (i.e., respiratory rate, inspiratory and expiratory periods, inspiratory/respiratory ratio and inspiratory/expiratory ratio) have been computed. Thus, considering the raw data collected by the FBG sensor closest to the heart the resting heart rate was calculated by using the Fast Fourier transform (FFT). Results show that both the big displacements at low frequency (related to the breathing) and the small displacements at higher frequency (related to the heart activity) can be collected with the proposed system allowing the evaluation of both the respiratory and cardiac activities during quiet breathing and apnea without artifacts on images, providing useful information about patient condition.