Dynamic Referencing for 3D Localization of Fiber-Optic Shape Estimation in Endovascular Interventions

In current clinical practice, fluoroscopy is used to track the catheter shape during endovascular navigation. To reduce radiation exposure for clinicians and patients, alternative approaches relying on electromagnetic (EM) tracking and fiber-optic shape sensing (FOSS) have been investigated. EM sensors can be fragile and sensitive to EM disturbances. FOSS alone does not provide localization which is essential for catheter navigation. In this work, a method for localizing a catheter's shape-sensing fiber with respect to a static reference frame without relying on additional sensors is proposed. The method exploits the approximate follow-the-leader motion that typically arises during catheter insertion. The proposed approach foresees hereto a method to dynamically identify stable reference segments to be used for localization. This method explores the potential to offer both shape sensing <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">and</i> localization with a single shape sensing fiber. The proposed method was validated in 3D vessel mock-ups. Results demonstrate the feasibility of the approach, with tip localization errors of -0.29 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 1.86 mm and 3.82 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 2.66 mm along and perpendicular to the vessel centerline, respectively, achieved over insertion depths up to 800 mm. This work offers an important step toward reducing reliance on radiation-based imaging and EM sensors in catheter-based interventions.