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Reasearch On The Localization Of Capsule Robot For Matching Anatomical Structure

Posted on:2021-01-27Degree:MasterType:Thesis
Country:ChinaCandidate:M WangFull Text:PDF
GTID:2428330611499808Subject:Mechanical engineering
Abstract/Summary:PDF Full Text Request
The advent of wireless capsule robots greatly reduces the patient's discomfort during gastrointestinal examinations,which increases the safety and stability of examinations in such complex environments as the gastrointestinal tract.How to accurately describe the position of the robot is one of the key issues in the research of capsule robots.Based on permanent magnet tracking technology,this paper proposes a relative position tracking method to match intestinal anatomy.Magnetic positioning tracking technology has the advantages of high positioning accuracy,small footprint and low price.The relative position refers to the position information of the capsule robot relative to a certain feature point or the length of the oral cavity in the gastrointestinal tract,and its description has important reference significance for the insertion of the instrument during the endoscopic surgery of the doctor.In order to describe the relative position,we propose a relative position tracking method.Firstly,the position of the capsule robot in space is obtained by magnetic positioning technology,and then the movement direction of the robot is judged by judging the change of the movement angle of the robot up and down time,and then the motion paths of different directions are fitted to fit the length of the intestine,and the superposition of the fitting paths of the individual parts finally gives us the relative position of the capsule robot calculated from a certain intestinal feature point.One disadvantage of the magnetic positioning technology is that the positioning range is narrow,and the magnetic field strength of the permanent magnet is attenuated with the cube of the distance,so that when the target is far away from the sensor,the tracking accuracy will be greatly affected due to the reduction of the signal-to-noise ratio.In order to better describe the position of the capsule robot,this paper proposes a largescale tracking technology based on magnetic field servo.By preset the distance threshold,when the target exceeds the threshold range,the magnetic positioning system will follow the target to ensure the target is always Both remain in the most efficient area for tracking accuracy.The experimental results of the intestinal model show that the proposed method has good positioning accuracy.The average positioning error rate of relative position in static positioning is 1.27%,and the maximum positioning error rate is 3.3%.In the proposed large-range tracking method based on magnetic field servo,the positioning error is greatly improved compared with the case of no servo,and the positioning accuracy is basically the same as that of the static small range.This paper demonstrates the effectiveness of the proposed method in positioning over a large area covered by the upper body.The relative position description can provide important positional reference information for endoscopic surgery.
Keywords/Search Tags:magnetic localization, relative position tracking, magnetic field servo, capsule robot
PDF Full Text Request
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