Cardioscopic Imaging to Guide Manual and Robotic Surgery Inside the Beating Heart

The transcatheter approach is gaining popularity for many cardiac procedures that have previously been performed as open-heart surgery. One of the major hurdles of transcatheter interventions, however, is providing imaging of sufficient quality for procedure guidance and monitoring. Ultrasound and X-ray fluoroscopy are the most common modalities utilized for the image guidance. While both are noninvasive, each has limitations in guiding interactions between the catheter and the tissue. Ultrasound images are of limited resolution and suffer from high noise. Fluoroscopy provides higher resolution, but the images are 2D and contain the catheter, but not the tissue. In short, both modalities lack ability to provide high-resolution images at the interventional site. Optical imaging at the tip of the catheter can augment the image guidance of these modalities by providing intuitive local images of the intervention site. The challenge of optical imaging inside the heart, however, is seeing through the blood. Three approaches have been attempted to overcome this challenge: infrared imaging [1], flushing with clear liquid [2] and introducing an optical window [3]. In the latter, a transparent optical window is pressed against the tissue to displace the blood so that the tissue becomes visible. The advantages of this approach are that it does not require continuous fluid injection into the bloodstream and also stabilizes the imaging location through the contact force for subsequent tool delivery. This abstract describes two of our cardioscope designs for intracardiac imaging. The first is a handheld instrument for tissue removal. The second smaller design, mounted on a robotic catheter, is being developed for transapical aortic paravalvular leak closure.