Shape Construction And Tip Estimation Of Continuum Robot Based On Ultrasound Images

Minimally invasive surgery is an important direction for the development of modern medical surgery.Because continuous robots can flexibly operate in complex and small bodies to meet the requirements of minimally invasive surgery,they are favored by researchers.In order to be able to accurately detect robots in the body,combined with the advantages of ultrasound without radiation,good real-time performance and relatively cheap,ultrasonic imaging technology is introduced as visual feedback.This paper proposes a method for detecting two types of continuous robots based on two-dimensional ultrasound images,one is a continuous robot without a prediction model,and the other is a continuous robot with a prediction model.By constructing an optical robotic arm ultrasound diagnostic system,the continuous robot in a parody can be accurately positioned in space.The system can collect data autonomously,realize the recognition,positioning and tracking of continuous robots through ultrasonic image processing and coordinate transformation,and combine curve fitting methods to complete shape reconstruction and end estimation.Based on the current continuous robot ultrasonic image sensing algorithm,using the principle of high sensitivity of metal to ultrasonic waves and preferential reflection on the upper surface to cause higher pixel values on the upper surface ultrasonic image,an ultrasonic image processing suitable for precise positioning in a small area is proposed.Algorithm,the histogram method.In this paper,shape reconstruction and end estimation experiments are performed for these two types of robots respectively.The puncture needle represents a robot without a prediction model,and the concentric tube represents a robot with a prediction model.In the experiment of the puncture needle,the subject uses the binary method to complete the preliminary positioning of the robot,then uses the Kalman filter algorithm to track the continuous robot,and finally uses the collected data to complete the shape reconstruction and end estimation of the puncture needle using curve fitting.Through the experimental error analysis,the puncture needle is scanned at a scanning interval of 4 mm,and the error of the end position estimation is less than 1 mm,which meets the requirements of most medical procedures,thereby basically solving the shape reconstruction and prediction of non-prediction models based on two-dimensional cross-sectional ultrasound images.Problems with end estimation.This method uses an optical robotic arm ultrasounddiagnostic system to achieve the conversion from a two-dimensional plane position to a three-dimensional space position through ultrasonic image calibration,and uses a Kalman filter algorithm to complete the tracking of a continuous robot in space.In the experiments of concentric tube robots,this project uses the positive kinematics model of the concentric tube,combines the drive control parameters and the constraints between the concentric tube and the tube to complete the prediction of the segment of concentric tubes,and simultaneously generates corresponding uniform ultrasound Probe scanning point.Then,the acquired data is combined with the ultrasonic image processing results to complete the robot spatial positioning.Finally,the constraint relationship between the tubes is used again,and the constraint equation obtained by the curve fitting formula is used to complete the shape reconstruction and end estimation of this segment.Through the experiments of two sets of concentric tubes,the average estimation error of the end position is less than 1 mm.This method uses positive kinematics model for the first time in combination with two-dimensional ultrasound imaging to complete the spatial positioning of a continuous robot with prior knowledge,and realizes its shape reconstruction and end estimation.The experimental results meet the requirements of most medical procedures.