Design Of Full HD Laparoscopic System

Laparoscopy is one of the most important diagnostic and surgical devices for minimally invasive surgery.The minimally invasive incision enters the human body to observe the fine lesions,so the clarity of the laparoscopic requirements is getting higher and higher.Fluorescent staining-assisted laparoscopic surgery was performed by binding the fluorescent contrast agent indocyanine green(ICG)to plasma proteins.When absorbing infrared light,ICG can release fluorescence,judge the tumor contour,and eradicate the tumor to the maximum extent without damaging blood vessels.The clarity of laparoscopic and its functional expansion have become the focus of laparoscopy research.The laparoscope consists of an objective lens,a relay system,and an eyepiece.The image formed by the objective lens is imaged by human eyes in the form of parallel light through a relay system and an eyepiece.Due to the imaging requirements of the visual optical system,the size of the exit pupil is only 1 mm to 2 mm.With the development of optoelectronic imaging devices such as CCD and COMS and high-resolution displays,TV laparoscopy has replaced traditional laparoscopy.The principle is to add optical interface optical system based on visual laparoscopy,and the focal length is generally 25 mm~ 30 mm,so the relative aperture of the TV laparoscope is generally about 1:13,which can not meet the requirements of high resolution.Electronic laparoscopy is limited by the built-in digital camera.In this paper,by changing the design structure of laparoscopic,the laparoscopic design is simplified into three parts: endoscopic objective lens,relay system and microscopic objective lens.The structure of the laparoscopic eyepiece and the optical interface was eliminated,and the overall design of the laparoscope was performed to increase the diameter of the entrance pupil and the relative aperture,achieving a relative aperture of 1:8,a full field of view of 80° and a 1080P(Full HD)resolution.According to the imaging characteristics of the fluorescence endoscope,the system adopts a dual-band common optical path imaging design.A set of equipment for optical laparoscopy and fluorescent laparoscopic surgery,the visible light band is 400 nm-700 nm,and the near-infrared band is 780 nm-850 nm.A spectroscopic prism is added to the rear end of the optical system to separate near-infrared light and visible light,which are respectively received by the infrared COMS and the visible COMS.Laparoscopic use requires the design of the laparoscopic structure,first of all to have a focusing structure to meet the target imaging of different distances.Secondly,there must be a detachable structure to meet the needs of disinfection,and analyze the stray light generated by the system,propose a suppression method,and then carry out processing and adjustment.The processed laparoscopic detection includes resolution,angle of view,viewing angle,distortion and other performance indicators,and the resolution of the object is 53 lp/mm,which can achieve full HD imaging.