1 research outputs found
Fast 5DOF Needle Tracking in iOCT
Purpose. Intraoperative Optical Coherence Tomography (iOCT) is an
increasingly available imaging technique for ophthalmic microsurgery that
provides high-resolution cross-sectional information of the surgical scene. We
propose to build on its desirable qualities and present a method for tracking
the orientation and location of a surgical needle. Thereby, we enable direct
analysis of instrument-tissue interaction directly in OCT space without complex
multimodal calibration that would be required with traditional instrument
tracking methods. Method. The intersection of the needle with the iOCT scan is
detected by a peculiar multi-step ellipse fitting that takes advantage of the
directionality of the modality. The geometric modelling allows us to use the
ellipse parameters and provide them into a latency aware estimator to infer the
5DOF pose during needle movement. Results. Experiments on phantom data and
ex-vivo porcine eyes indicate that the algorithm retains angular precision
especially during lateral needle movement and provides a more robust and
consistent estimation than baseline methods. Conclusion. Using solely
crosssectional iOCT information, we are able to successfully and robustly
estimate a 5DOF pose of the instrument in less than 5.5 ms on a CPU