Sensorless Real-Time Force Estimation in Microsurgery Robots Using a Time Series Convolutional Neural Network

Robotic-assisted microsurgeries provide several benefits to both patients and surgeons. Nevertheless, there are still some limitations and challenges associated with their outcome, one of which is a lack of force feedback. Without force information, the risk of delicate tissue damage from the excessive force applied by surgeons would be increased. Since it is difficult to install force sensors on microsurgical tools, a novel approach for estimating a force vector from the deformation of the surgical tool is proposed in this paper. In the proposed approach, a surgical instrument that deforms according to the magnitude of the tool-to-tissue force is designed, and a time series convolution neural network is used to make the nonlinear relationship between the visual information of the deformation of the surgical tool and the applied forces in such a way that the tool-to-tissue force can be estimated according to the deformation of the surgical instrument in a real-time manner. The experimental results prove that the applied force can be successfully estimated with high accuracy in three dimensions using the proposed method.