Optically-guided Surgery

OCT-Guided Surgery

John was the optical systems designer and principal engineer on the Nighthawk™, the first-in-man intravascular image-guided plaque excision catheter. This was the first real-time optical coherence tomography (OCT)-guided intravascular surgical procedure performed in humans, and one of the earliest OCT-guided human surgical procedures of any kind. (Bibliography – Radvany & Kiesz, 2008, PDFs – Gammon NCVH 2007).

After FoxHollow, he led the imaging team at Avinger in the development of OCT-guided catheters for the treatment of chronic total occlusions (CTOs – Ocelot™), a severe end-stage form of peripheral / coronary artery disease that can lead to amputations and bypass surgery. The Ocelot™ is FDA approved and on the market.

These projects demonstrated unambiguously that modern fiber-optics technology can be applied to medical devices and considerably increase the capabilities of the device but without adding excessive cost or complexity to the device.

We are currently engaged in several projects in image-guided surgery including adding OCT and fluorescence guidance to surgical tools to give clinicians an unambiguous treatment decision, in real-time, with 50-micron placement precision and with identification of the tissue they are interacting with. We have also worked on applying OCT in robotics, with the OCT signal acting as guidance for probe placement and a sub-mm-scale, real-time collision avoidance system.

Optical Coherence Tomography

Coming soon

Tissue Optics

Absorption, remittance and fluorescence from tissue can be a powerful tool in identifying certain biological tissues. The image below shows a commercial VeinViewer™ being used to identify the blood vessels on the back of the hand. This device works via the differential absorption and remittance (“reflectance”) of various wavelengths in tissue where chromophores (absorbers) are spatially distributed. In this case the absorber (hemoglobin) reduces the amount of infra-red (> 700 nm) light being returned from the areas over the vessel – this absorption is registered by a camera in the system and the position of the vessel is back-projected on the hand by another visible laser.