Posts with the tag: tracking
Recently, there has been a lot of interest in the application of optical coherence tomography (OCT) to retinal surgery. While OCT is already established as a tool for diagnosis and pre-surgical planning, the idea of imaging during the surgery itself hasn’t found much traction. Initially, this was partly due to the lack of commercial OCT systems that were well-integrated with ophthalmic microscopes. This meant that the surgery had to be halted, the ophthalmic microscope removed, and the OCT slid into place every time an OCT image was wanted. More recently, Carl Zeiss and Haag-Steit have begun marketing devices where the OCT is integrated into the surgical microscope, so that both can be used simultaneously. The OCT images can then be displayed to the surgeon in the microscope view. However, the authors of a recent paper in Biomedical Optics Express claim that these integrated OCT systems are still not ideal. Instead, they propose an OCT scanner which is built into the surgical instrument itself.
Optical Coherence Tomography (OCT) images are usually built up scanning a laser spot rapidly over the sample. For the common applications of eye and skin imaging there aren’t any particularly onerous size constraints on OCT systems, so bulky galvanometer mirrors can be used to generate the scan. But for endoscopic imaging we need to minimise the size of the mechanism. This has resulted in the development of a number of miniaturised scanning systems, mostly involving MEMS mirrors and fibre scanning cantilevers. One of the more esoteric solutions is the idea of free-hand scanning, where the operator builds up a scan simply by moving the probe manually. This reduces the hardware requirements to a minimum, but leads to the tricky problem of how to correctly assemble the image when we don’t know how the probe has been moved.