Development and Evaluation of Tri-Axial Fiber Bragg Grating in a Measurement Module for Catheterization

Cardiac catheterization does not usually involve the use of a force sensor. During cardiac catheterization, whether to use a force sensor, which is based on electrical and solid-state sensors, is an important consideration for the physician. However, such sensors may cause electromagnetic interference (EMI) in the operating room, which contains many electrical instruments. It is one of technical challenge for removing EMI with applying a force sensor is a technical challenge. The use of an optical fiber force sensor can be an alternative force sensing method for achieving safe and minimally invasive surgery. Two different flexure structures for the catheter tip were designed and simulated using ANSYS to verify their sensitivity and durability. The flexure structures were used to protect the optical fiber sensor. Fiber Bragg Grating sensors were configured to measure the tri-axial force applied on the catheter tip. An optical sensing interrogator shows the variations of the Bragg wavelength. A lab-designed LabVIEW program was used to control the motion of the optical fiber force sensor and measure the force value and Bragg wavelength, separately. The experiment was carried out three times for repeatability. The calibrated wavelength output shows that an optical fiber force sensor can measure an axial force of up to 50 gF with 1 gF resolution for high accuracy. The results demonstrate the reliable measurement capability of the force measurement setup, as well as its high accuracy with repeatability.