Fiber Bragg Grating Strain Sensor Incorporated to Monitor Patient Vital Signs During MRI

This paper reports on results obtained from monitoring the respiration and cardiac activity of a patient during a magnetic resonance imaging (MRI) survey using an optical strain sensor based on a fiber Bragg grating. The sensor is proposed specifically to acquire ballistocardiographic signals from a patient exposed to high intensity electromagnetic radiation. A Bland-Altman analysis shows the measurements that have a satisfactory accuracy for monitoring purposes, and the relative error is <8%. The method is both noninvasive and safe for the patient. In addition, the sensor does not affect the MRI imaging quality.