Optical system design of the head-mounted projective display for vein imaging

In order to assist venipuncture and related medical operations, a novel vein imaging device based on head-mounted projective display(HMPD) is designed. The correspondent optical system consists of near-infrared imaging system and see-through HMPD. With the help of optical design software ZEMAX, the near-infrared imaging system has a large numerical aperture with F number of 2.6, which is extremely conducive to receive and to image the weak reflected near-infrared light. The structure of the optical system of HMPD is same as that of near-infrared imaging part, which is conducive to simplify the processing and assembly. The results indicate that the performance of imaging system is excellent and the resolution is up to QXGA(2 048×1 536). The see-through HMPD possesses an 18 mm exit pupil and a 25 mm eye relief, with the field curvature less than 0.03 D, the distortion less than 0.32% and the resolution up to QXGA. Compared with the current vein imaging device, the proposed system is characterized by compact structure, comfort wearing and ultrahigh resolution, which is suitable for assistant tools in venipuncture techniques.