Research On Key Technologies Of Robot Assisted Ultrasound Image Surgical Navigation

Computer-aided surgical navigation is a technology that combines multiple disciplines such as computer science,information management,and image processing.This technology is designed to use computer technology to simulate the entire surgical environment during the operation,and then visualize the entire operation in 3D to help doctors successfully complete the operation.Among them,image-guided surgical technology is the most widely used,which is an emerging minimally invasive treatment method.At present,the technology of applying computed tomography,X-ray imaging,and nuclear magnetic resonance imaging is relatively mature,but computed tomography and X-ray imaging will cause radiation damage to the human body during the imaging process.Therefore,thesis studies the technique of tracking the puncture needle tip using ultrasound images.The research focuses on the calibration of the ultrasound probe,the calibration of the puncture needle tip,and the tracking of the puncture needle tip based on the ultrasound image,and focuses on the tracking of the puncture needle tip based on the ultrasound image.The main research results are as follows:1.A new calibration method for puncture needle tip is proposed,which calibrates the coordinates of the puncture needle tip in the instrument coordinate system.A template coordinate system is obtained by optimization using 253 optical spherical image coordinates in the camera coordinate systems.Then,the coordinates in the template coordinate system are transformed into the instrument coordinate system to obtain the coordinates in the instrument coordinate system.Next,the needle tip coordinates in the instrument coordinate system are transformed into the camera coordinate system,and the needle tip coordinates are obtained by optimizing the gradient descent method,which proves the accuracy of the puncture needle tip calibration method.The calibration error of the puncture needle tip obtained by this method is 0.1644 mm.2.A new method of ultrasonic probe calibration based on N-line is proposed,which calibrates the transformation matrix from the image coordinate system to the ultrasonic probe coordinate system.In view of the advantages and disadvantages of the traditional N-line ultrasound probe calibration method,a puncture needle tip calibration method is proposed to find the coordinates of the two ends of each N-line to solve the N-line equation,and to calculate the transformation matrix from the image coordinate system to the ultrasound probe coordinate system.,which proves the accuracy of the ultrasonic probe calibration method.The pixel deviation of the ultrasound image obtained by this method is 1.5373 mm.3.A method of puncture needle tip tracking based on ultrasound image is proposed,which tracks the position of the xoy plane.In the xoy plane,use the controller to position the ultrasound probe.Then,the coordinates of the needle tip puncture needle in the fixed coordinate system are calculated.At the same time,a Kalman filter is added to reduce the influence of noise on the tip and predict the subsequent state.Finally,whether the image information of the puncture needle tip can be detected by the ultrasonic image is used to servo the speed of the ultrasonic probe,so that the ultrasonic probe can track the puncture needle tip in real time.The tracking performance of the method using Kalman filtering for position and velocity is better.Experiments show that the method of Kalman filtering based on the position and angle of the needle tip improves the tracking performance.