High speed, area CMOS camera for phase stable imaging and Computational Adaptive Optics

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Optical methods that can image the structure and blood flow of biological tissue and probe its normal / abnormal function in-vivo, non-invasively and with cellular-level resolution, can be used clinically for real-time, non-contact optical (virtual) biopsy. As such, they have the potential to revolutionize the early diagnostics and to aid the treatment (surgical and non-surgical) of many diseases, from potentially blinding neurodegenerative retinal diseases to various types of cancer. Optical Coherence Tomography (OCT) is an imaging modality that can image in-vivo, non-invasively and simultaneously the cellular structure, blood flow and physiological function of biological tissue. However, the OCT images suffer from optical aberrations such as defocus, astigmatism and chromatic aberrations, which cause image distortions and blur. When applied to OCT images, an image processing algorithm named Computational Adaptive Optics (CAO), can compensate numerically these aberrations. Processing OCT images with CAO requires that the images are free of motion artefacts. Heart rate, breathing rate and involuntary muscle twitching which occur at frequencies of ~0.5Hz to ~3Hz, can introduce motion artefacts in the images if the OCT image acquisition rate is comparable to or slower than these motions. Current OCT systems use linear array cameras with frame rates < 200 fps, therefore the volumetric OCT imaging rate is < 0.2 Hz. Recently, our research group has developed OCT technology based on an ultrafast area camera (~2,500 fps) that can achieve volumetric imaging rate of ~2.5Hz which can suppress some, though not all motion artefacts and especially fast eye motion. Here, we propose to replace the old camera with a new one which offers a frame rate of 4,500 fps, sufficiently high to suppress effectively motion-induced image artefacts and therefore allow for processing of the OCT images with CAO. The new ultrafast camera provides optimal combination of pixel resolution (2560 x 1920), fast frame rate (4,500 fps) and low noise. The camera can be integrated easily into a fully operational OCT system already available in our research lab and the integration will require minimal hardware and software modifications of the current OCT system. As an integral part of the OCT system, the new camera will be utilized for a number of collaborative research projects focusing on fundamental and applied biomedical research of various diseases such as potentially blinding ocular pathologies (age related macular degeneration, diabetic retinopathy, glaucoma, etc.), neurodegenerative conditions (Alzheimer's, etc.) and various types of cancer. Students working on this research will benefit from research that is made more competitive through the addition of the new camera to the OCT system and the capabilities it will provide. It will enable their work to be published in high-impact factor journals such as “Nature Biophotonics” and Light Science and Applications”.