Development of Tri-axial Fiber Bragg Grating Force Sensor in Catheter Application

Abstract

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 operation room since many electrode instruments are existed. 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 a safe and minimally invasive surgery. Two different flexure structures for catheter tip were designed and simulated using ANSYS to verify their sensitivity and durability. The flexure structure was 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 Bragg wavelength. A lab designed LabVIEW program was used to control motion of the optical fiber force sensor and measure the force value and Bragg wavelength, separately. The experiment was carried out at three times for repeatability. The calibrated wavelength output shows that an optical fiber force sensor can measure an axial force of up to 0.5 N with 0.02 N resolution for high accuracy. The results demonstrate the reliable measurement capability of the force measurement setup, as well as its high accuracy with repeatability.