Research On Information Collection And Control Of Medical Robot

Minimally invasive surgical robot(MISR) technology which based on traditional minimally invasive operation had combined robotics with medical science and promoted the development of surgical operation. The MISR has the advantages of less blood loss, little trauma, high operational precision, high flexibility, comfortable operation for a doctor and the removal of hand shake. The motion control is an important part of independent research and development for the MISR system, especially for the isomeric master-slave robot system. In this study, we researched on the motion control, force sensing and force feedback function based on the developed MISR hardware system. The main research contents are as follows:1. We fully analyzed the mechanical structure of both master and slave part developed by our group and found the forward kinematics and inverse kinematics solution of them. The feasibility was proofed in the case of there is a fixed point during the MISR by calculating the work space of both master and slave part. We analyzed the situation of the master and slave part suffering force and torque, determined the kinetic model and properties which provided the basis for force-position bilateral control. In order to achieve master-slave control as the goal, this study has proposed a control method for the isomeric master-slave MISR. In view of this robot system has the characteristics of multi degree of freedom and a different structure, control strategy has been proposed to separation of position and posture to reduce calculation and improve real-time performance. Through the analysis of the control algorithm of PID effect on motor control, we used the fuzzy PID algorithm for motion control. This study has built a hardware control system for MISR and developed a software control program with a good interactive performance. The system showed good motion performance with the control algorithm in the master-slave following experiment, and satisfied the basic requirements of surgical operation. In addition, in the aspect of human computer interaction, this study has designed Alfa filter to carry out the shake of hand. Experiments show that the filter has a good smooth effect on the out of the motor.2. Aiming at the lack of force perception of MISR, this paper has put forward a method to determine the calibration matrix of a novel six axis force/torque sensor with small size for MISR. We analyzed the situation of the sensor suffering different force and torque and the sensitivity and cross axis coupling by using the finite element analysis(FEA) and. In addition, we designed a calibration platform and completed static calibration for the sensor. The calibration curves and coupling coefficient matrix were acquired by using the least squares method(LSM). Experimental tests and calibration error analysis showed that the proposed sensor has high accuracy and appropriate range. We placed the sensor in the end of slave part, and experimented touching and twisting as similar actions in surgery with pork liver. Experimental tests showed that the proposed sensor can meet the need of force sense perception of the minimally invasive surgical operation due to its high accuracy and appropriate range.3. According to the MISR developed by our laboratory, we researched the force feedback function in this paper, focusing on how to reproduce the force information collecting by the sensor on the master manipulator. We explored the relationship between the force and torque current and determined the linear relationship between them. This study has proposed an algorithm to achieve the force perception and force feedback function for MISR. The force perception and force feedback function of MISR has been preliminary achieved thr ough collecting force information by six axis force sensor in real time.4. Furthermore, according to the upper limb rehabilitation equipment developed by our group, this study has proposed a method to quantify the upper limb rehabilitation training and assessment. We have developed the data collecting system. The joint angle data was used to fit reality and virtual environment together. And the electromyographic signal was used to evaluate the influence of the equipment on the human muscles. Finally, the rehabilitation effect of the equipment was researched by the patients experiment.