Shape-sensing systems and methods for medical devices

A method for determining a tip of a catheter is positioned in a superior vena cava (“SVC”), comprising:

• advancing the tip of the catheter through a vasculature toward the SVC, the catheter including an integrated optical-fiber stylet having a plurality of fiber Bragg grating (“FBG”) sensors along at least a distal-end portion of the optical-fiber stylet for shape sensing with a shape-sensing system including the catheter;
• enabling an optical interrogator of the shape-sensing system to send input optical signals into the optical-fiber stylet while advancing the tip of the catheter through the vasculature;
• enabling the optical interrogator to receive FBG sensor-reflected optical signals from the optical-fiber stylet while advancing the tip of the catheter through the vasculature;
• enabling the optical interrogator to translate the FBG sensor-reflected optical signals into reflection data representative of the FBG sensor-reflected optical signals;
• enabling a console of the shape-sensing system to convert the reflection data into plottable data for at least a plot of curvature over time for a selection of the plurality of FBG sensors in the distal-end portion of the optical-fiber stylet;
• and
• identifying on a display screen of the shape-sensing system a distinctive change in the plot of curvature of the optical-fiber stylet over time for the selection of the plurality of FBG sensors in the distal-end portion of the optical-fiber stylet at a moment the tip of the catheter is advanced into the SVC, thereby determining the tip of the catheter is located within the SVC.