High resolution fiber optic manometer based on FBG and polymer diaphragm.

Abstract

Use of in-vivo blood pressure sensors is important during surgeries where a constant measurement of the blood pressure indicates the patient’s status and reaction to anesthesia. This allows the surgeons to plan their responses accordingly. In order for easier intubation and demodulation, smaller and more flexible devices need to be innovated thus Fiber Bragg Grating (FBG) based sensors are increasingly being studied for its application to monitor distributed pressure caused by in-vivo disorders. However, as a bare FBG often has a very low sensitivity to external pressure, a polymer diaphragm was used in this study to enhance and transduce surrounding changes to the employed FBG, thus leading to Bragg wavelength shift to acquire target parameters. Substrates differing in material, shape, and area of opening, were tested and compared to see which could increase the FBG sensor sensitivity. An added modification using a basal wood block was also tested. It is shown that a rectangular aluminium substrate with the added design modification yields the highest sensitivity. However, in order for the FBG sensor to be functional in surgical applications, further improvements need to be implemented to ensure higher biocompatibility and easier intubation.