A multiple modality localization algorithm for catheter interventions.

摘要

Localization of steerable catheters in minimally invasive surgery is critical with respect to patient safety, surgeon manipulation, and procedural efficacy. While there are many potential benefits to patients including shorter recovery times, less tissue trauma, and lower infection rates than traditional surgeries, localization of surgical tools is still an area of much research. Current technology offers several sensory modalities including fluoroscopy, magnetic resonance imaging, computed tomography, and ultrasound. However, each system has drawbacks which do not provide a clear choice for best practice. This dissertation focuses on incorporating redundant commonplace surgical sensing technologies to reduce the likelihood of errors, failures, or inherent sensor characteristics possibly causing harm to the patient and/or surgeon while providing accurate localization. Dual particle filters are implemented using both a fluoroscopic-like stereo imaging system and an electromagnetic pose sensor for measurement updates in a prototype catheter test bed. A previously developed catheter model is modified and a rigorous calibration procedure is developed to increase accuracy in the particle filter outputs which are combined using a weighted average based on each filter's particle statistics. Experimental results implementing the combined particle filter multi-modal algorithm in feedback control validates the algorithms ability to provide accurate localization in a surgical setting while overcoming sensor limitations and possible failure modes.