Image Processing Method Of Insect Development Based On OCT Technology

Insect resources are one of the richest resources in the world,with the characteristics of fast reproduction,high survival rate and easy rearing.Physiological studies on insects help to obtain precise knowledge of insect development and are of great value for the control of harmful insects and the conservation and utilization of beneficial insects.Traditional research methods are mostly invasive,such as microscopy and tissue sectioning,which consume a lot of experimental samples,experimental funds,and researcher's energy.At the same time,the morphology of the samples can be artificially changed or even damaged when the samples are fixed for observation.Therefore,it is necessary to introduce non-invasive methods into insect physiology research.Optical Coherence Tomography(OCT)is a new optical imaging technique developed in the 20th century,which takes advantage of the low coherence of near-infrared light to obtain a laminar image of the depth direction of the sample by detecting the interference information in the backscattered light of the sample.The imaging characteristics of OCT technology can achieve real-time developmental monitoring of insects,while being able to monitor the dorsal vascular pulsation of insects,and can extract changes in the pulsation rate and pulsation amplitude of dorsal vessels.However,when using OCT technology to track and monitor insects at the embryonic stage,the presence of the egg shell affects the visualization of the OCT 3D reconstruction map,making the 3D map of the embryo inside the egg cannot be clearly presented.Meanwhile,after acquiring the images of the pulsation changes of the dorsal blood vessels of insects,an effective image processing method is needed to extract the pulsation amplitude of the dorsal blood vessels in order to accurately acquire the amplitude changes of the dorsal blood vessels.Based on the study of insect embryonic stage,this paper combines the characteristics of OCT imaging,selects the East Asian flying locust as the insect sample,and designs an image processing algorithm to eliminate the effect of eggshell.The method can automatically identify the eggshell region and erase it,thus presenting only a clear 3D image of the embryo inside the insect egg.In combination with this algorithm,the development of the flying locust embryonic stage,including embryo rotation and embryo twisting phenomena,was recorded.This image processing algorithm is an important reference value for applying OCT technology to study insect embryo development.Meanwhile,the pulsation rate of the dorsal blood vessels of the flying locust was recorded by parameter settings.The dorsal vessels are the closed structures of the East Asian flying locust circulatory system,and the beat rate and beat amplitude of the dorsal vessels are of great value in the analysis of the physiological characteristics of the heart.In order to compare the difference of dorsal vascular pulsation rate between different developmental stages of the locust,the changes of dorsal vascular pulsation rate were observed and recorded during the whole life cycle of the locust,including embryonic stage,locust cyst stage and adult stage.In addition,we also compared the dorsal vascular pulsation rates of swarming locusts with those of dispersing locusts.In order to accurately obtain the variation of dorsal vascular pulsation amplitude,the horizontal set method was applied to extract dorsal vascular contours for the first time in this paper,and the horizontal set method was also compared with the minimum error method to analyze and compare the dorsal vascular pulsation amplitude.