Spatial Surgical is developing a novel, first-in-class orthopedic laser system that rapidly and safely ablates soft tissue and bone through a single handpiece. Spatial?s technology couples a laser with a real-time digital video system to offer computer-guided surgery that stands to replace traditional orthopedic saws, drills, and cauterization tools. The digital 3D video system is two miniaturized CMOS-based cameras built into the laser hand- piece. By eliminating mechanical tools an unobstructed, intra-operative view of the surgical site is possible for the first time ever. In-between the laser pulses, the cameras flash to capture an unobstructed view of the surgical site. The dual cameras are connected to a 3D display. Advances in autostereoscopic 3D displays have eliminated the need for 3D glasses, referred to as ?glasses-free?, and enabled wide angle viewing. 3D viewing of the surgical area promotes increased spatial understanding of complex/ambiguous scenes and enhances surgical efficiency (McIntire 2014). Coupling image recognition software with the 3D vision enables AI measurement and computer assisted navigation. Orthopedic surgical success, measured as less patient pain and fewer revisions, has been shown when measurement and navigation are used, but existing systems are expensive and slow. A laser surgical hand-piece coupled with HD 3D vision and measurement will enable more accurate implant placement and restored range of motion while reducing infections and decreasing surgical times. This SBIR program models, tests, and demonstrates 3D viewing including digital zoom. Initially a multi-element design is modeled to predict what lens assembles would match with the digital CMOS imager appropriate for the orthopedic HD 3D application. Secondly off-the-shelf, OTS, lens stacks are chosen based on the optical modeling, and are tested to define the balance between the FOV, focal length, object distance and image size. Lens stack stereo characteristics are recorded and subsequently derive the forward-looking design requirements. Additionally, various illumination levels are explored to determine the optimum lighting for each lens stack. A standard vision calibration chart, like Mil-Std-150A, is used for alignment and the edge response is used to define spatial resolution. Multiple bone cut samples are measured with a confocal microscope and then viewed in 2D with the various OTS lens stacks. Optical measurement software is used to process the OTS lens camera images and are graphed versus the microscope data to determine peak image performance for spatial resolution.
The introduction of HD autostereoscopic monitors and high pixel count CMOS global imagers enable a 3D surgical vision system to aid in orthopedic surgical applications by providing 3D glasses-free and wide angle viewing to improve spatial understanding of joints for faster and more precise surgery.
