Keynote address: The role of augmented reality displays for guiding intra-cardiac interventions

Many inter-cardiac interventions are performed either via open-heart surgery, or using minimally invasive approaches, where instrumentation is introduced into the cardiac chambers via the vascular system or heart wall. While many of the latter procedures are often employed under x-ray guidance, for some of these xray imaging is not appropriate, and ultrasound is the preferred intra-operative imaging modality. Two such procedures involves the repair of a mitral-valve leafet, and the replacement of aortic valves. Both employ instruments introduced into the heart via the apex. For the mitral procedure, the standard of care for this procedure employs a 3D Trans-esophageal echo (TEE) probe as guidance, but using primarily its bi-plane mode, with full 3D only being used sporadically. In spite of the clinical success of this procedure, many problems are encountered during the navigation of the instrument to the site of the therapy. To overcome these diffculties, we have developed a guidance platform that tracks the US probe and instrument, and augments the US mages with virtual elements representing the instrument and target, to optimise the navigation process. Results of using this approach on animal studies have demonstrated increased performance in multiple metrics, including total tool distance from ideal pathway, total navigation time, and total tool path lengths, by factors of 3,4, and 5 respectively, as well as a 40 fold reduction in the number of times an instrument intruded into potentially unsafe zones in the heart.