A FBG-OCT Catheter to Reconstruct Vascular Shape in Intravascular Optical Coherence Tomography

We propose a novel fiber Bragg grating (FBG)-optical coherence tomography (OCT) catheter to reconstruct vascular shape by intravascular OCT imaging of the actual curvature as well as the bending direction of the vascular in real-time. Compared with the traditional OCT catheter, the FBG-OCT catheter uses the FBG encapsulated with half- sectioned stainless-steel tube as a flexural sensitive component. With the 360-degree rotation of the catheter, the encapsulated FBG will produce maximum tension and maximum compression at the bend of the blood vessel, and then get the solution of the curvature and direction of the bending catheter as well as the OCT imaging simultaneously. To test the proposed catheter for real-time measurement, a bending calibration system and a vascular prosthesis model to simulate the actual vascular bending morphology are manufactured through three-dimension (3D) printing. Experimental data shows that the new FBG-OCT catheter can acquire the OCT images and FBG bending parameters real-timely and synchronously. Further, the obtained bending parameters and OCT images are used to restore the morphology of the vascular model, which will provide corrective data for accurate measurements of further vascular plaques, blood flow, and intravascular pressure.