Design And Implementation Of A System For Rats Behaviour Analysis Based On DM642

Animal behaviour experiments are widely used in the research of animals’behaviour, brain science, drug effect analysing and so on. Rats are the mostcommonly used experimental animals in laboratory, and “Open-field test” is oneof the most popular methods to study animals’ behaviours. The recording methodhas been developed from manual recording, mechanical sensor recording, to analogvideo tracking and digital video processing. Manual recording costs a lot of labors, andresult varies from one to another. Mechanical sensor recording saves labors, but theinformation is limited; Comparing with analog video tracking, digital video processingis the trend of the future. Most of the digital video monitoring methods are based on PCat present, the costs are very high. So an embedded system based on DM642isproposed for rat’s Open-field test.The system contains four parts: rat’s moving platform, two cameras, videoprocessing hardware and video output module. Rat’s moving platform is a cubic box,one camera is placed above the box and the other is placed on the side of the box. Theprocessing hardware controls the two cameras, processes the data which transmittedfrom cameras and then displays them on an LCD. It is a video capture card design byauthor, it adopts TI’s TMS320DM642as MCU, and contains video encoding module,video decoding module, SDRAM module, FLASH module, keyboard module andpower supply module, which can meet the needs of two channel videos inputting, dataprocessing and video outputting in real time.The process of video processing including image binarization and imagemorphological operation, to extract the region of interest, then calculate thegeometric center of gravity position of the rat. After this, statistics rat’s movingdistance, position and total times of each state. At last, calculate the rats’average speed, staying position distribution and times of each state.Use a rat model to test the system, the results of experiments are consistentwith the theoretical values, the position result errors are less than0.1%anddistance result errors are less than3%. The next test includes two experimentsusing a rat: the open field test and the circadian rhythm experiment. In the openfield test, rats active less and stay long around the platform in the beginning because of fear; as experiment goes on, rats’ activities increase and theexploration activities to the center also increase. The circadian rhythmexperiment shows that rat’s most active time is9:00am, and the least active timeis15:00pm, Then the rat’s activity recovers at21:00pm. The results areconsistent with the references.The experiment results show that this system is able to monitor the rat’sbehaviour in open-field test, it has the advantage of low cost, low powerconsumption, non-invasion and stability. But its function is simple, and theimage processing algorithm also needs improvement, so further researches andexplorations are needed.