LC-FBG Based Microwave Photonic System for Wheelchair Patient Pose Monitoring

Abstract

The paper presents the results of designing a data collection system aimed to prevent pressure sores and ulcers in immobile patients, most of the time are in a wheelchair. Three variants of sensor part of system are discussed. In all variants, two similar linearly chirped fiber Bragg gratings (LC-FBG) are used forming one system sensor: first for patient pressure sensing, second for temperature compensation. In first variant, we used classical LC-FBG. In second one, both gratings in center had one phase $\pi$-shift. The use of such gratings will reduce the cost of the spectral interrogation system, which limits the use of similar fiber-optic systems in medical practice. The interrogation system used for these type sensors belongs to microwave photonics class. In third variant, the second pressure sensor based on address LC-FBG with two phase $\pi$-shifts were utilized. The use of such type sensors will solve the problems of addressing the information received from specific wheelchair zones connected with right and left shoulder blades, buttocks and heels.