Development of vessel position estimation system based on pixel-wise refocusing using light field imaging

Venipuncture is a medical practice which is ordinarily performed in hospital. However, it is a difficult procedure as the occurrence of many failure of the puncture and sometimes medical accidents such as nerve damage and blood vessel damage are reported. This is caused by the difficulty of visually identification of the blood vessel. Although the depth information of the blood vessel is also important, the existing system in clinical practice can visualize vessels only by two dimensional images. In our previous work, we proposed a method that adds angle filtering to a refocus-based system using light field imaging to estimate the three-dimensional position of blood vessels. Angular filtering can reduce blurring of blood vessel image obtained using infrared light due to the strong scattering properties of biological tissue. By applying the refocusing technique to an image with reduced blur, it is possible to obtain enhanced cross-sectional information of a blood vessel using near-infrared light at each depth. However, in the previous study, only phantom model results were reported, and it was not possible to study practicality. In this paper, we report the results of applying and verifying the effectiveness of the proposed method to human hand.