The beam theory-based collision force detection of the catheter operating system

The catheter-based operating system is a specific surgical technique that can reduce the pain of the patients and permit a faster recovery compared with the conventional open surgery. It has gained increasing acceptance by the clinicians and patients. This technology has gradually matured. And it has started to extend from the therapeutic areas of cardiovascular disease to the cerebral vascular disease with the continuous development of the intravascular interventional operative technique. However, compared to the cardiovascular, the cerebral blood vessel is more fragile. So it is necessary to strictly control the operating force during the process of catheter insertion in order to avoid the irreparable damage. Simultaneously, the cerebral vascular is more narrow than the cardio blood vessel, which makes it impossible to use the catheter equipped with the special sensors during the surgery procedure. Hence it is hard to achieve the real-time monitoring and detection of the tool/tissue contact forces. Therefore, it is essential to realize the collision force detection in the distal of the catheter for the cerebral vascular interventional procedures. In order to improve the safety of surgery and avoid the contact force between the catheter and the blood vessel wall over the threshold value that the vessel can withstand. This paper proposed a method that modelling the distal part of the catheter using the beam theory that based on the morphology captured from the image. Meanwhile, a static force-tip model by using a pseudo-rigid-body 3R model have been developed and validated in this paper. The presented model detected the collision force at the catheter tip on the basis of the distal position and orientation information through extensive experimentally. It is demonstrated that the proposed method can estimate the constant force in the distal catheter without directly measuring the applied force at the tip.