Surgical accuracy under virtual reality-enhanced ultrasound guidance: an in vitro epicardial dynamic study

In the context of our ongoing objective to reduce morbidity associated with cardiac interventions, minimizing invasiveness has inevitably led to more limited visual access to the target tissues. To ameliorate these challenges, we provide the surgeons with a complex visualization environment that integrates interventional ultrasound imaging augmented with pre-operative anatomical models and virtual surgical instruments within a virtual reality environment. In this paper we present an in vitro study on a cardiac phantom aimed at assessing the feasibility and targeting accuracy of our surgical system in comparison to traditional ultrasound imaging for intra-operative surgical guidance. The 'therapy delivery' was modeled in the context of a blinded procedure, mimicking a closed-chest intervention. Four users navigated a tracked pointer to a target, under guidance provide by either US imaging or virtual reality-enhanced ultrasound. A 2.8 mm RMS targeting error was achieved using our novel surgical system, which is adequate from both a clinical and engineering perspective, under the inherent procedure requirements and limitations of the system.