Trans-blood Imaging in the Heart using a Real-time Infrared Endoscopic System
Intra-operative imaging during cardiac surgery remains insufficient for many applications. For example, intra-operative visualization of heart valves has not been standardized and current research techniques primarily utilize ultrasound, which exhibits poor contrast at the interface of blood and valve tissue. Sufficient resolution and contrast have been obtained with MRI, but the technique is slow and it is not currently practical nor routine to perform real-time MRI imaging for intraoperative use. Standard optical endoscopy has not translated because of the significant scattering and absorption of blood at the UV/VIS wavelengths. However, based on Mie optical scattering theory, imaging through blood using infrared light is theoretically feasible. In this project, we utilized components and technology from IR wavelengths (e.g. 1550 nm) to design a rigid endoscope that optimized tradeoffs between absorption and scattering to achieve optical imaging in real-time through blood. The results of optical ray-tracing simulations demonstrated that a rigid endoscopic system that images through blood with 50 μm resolution is feasible.