Research On Detection Technology Of Surgical Interaction Force Applied On Minimally Invasive Surgical Robot

Robot-assisted minimally invasive surgery(RMIS)improves the flexibility and stability of the operation compared with the traditional open surgery and minimally invasive surgery.However,the surgeon cannot feel the surgical interaction force between the surgical instrument and the soft tissue.Therefore,the surgeon cannot distinguish the characteristics of the tissue or organ lesion by tactile sensation.At present,researchers still face many problems such as low sensing accuracy,poor real-time ability,poor biocompatibility,difficult sterilization of surgical instrument and so on.Therefore,the further development of RMIS is limited.In this paper,we develop a force feedback mechanism for RMIS to solve these problems.We study the methodology to collect the interaction information between the surgical instrument and soft tissue and then calculate the force information based on the biological soft tissue model of different surgical operation and then feedback the interaction force to the surgeon.Specific contents as following:Firstly,we analyze the surgical interaction force based on the mechanical characteristic of biological soft tissue.And then we completed numerous vitro experiments to imitate the surgical operation as well as collect the surgical force information simultaneously to establish the force model to reflect the change law of the surgical interaction force.Secondly,the CT images of human abdominal cavity is pre-processed to enhance the features of the image.And we adopt the optimized image segmentation algorithm to segment the CT images to extract the target region.Then we adopt the three-dimensional reconstruction technology to process segmented tissue to reconstruct the virtual 3D model of human organ.The contour information and position information are extracted based on the 3D model.Thirdly,we develop the optimized fast collision detection algorithm.According to the motion and position information of the surgical instrument and the position and contour information of the human organ extracted from the reconstructed model,the collision moment and position are determined.The motion information of the instrument is loaded on the force model of different surgical operation to reflect the change rule of the surgical interaction force when the instrument is in collision with the human organ.Finally,we compare the output of the experiment in actual environment with the output of the detection method.The result shows the method could reflect the change rule of the surgical interaction force.