# Advantage of Steerable Catheter and Haptic Feedback for a 5-DOF Vascular Intervention Robot System
## 5 Discussion  
We examined the effectiveness of a steering catheter and a haptic function in the vascular intervention procedure. A 5-DOF vascular interventional robot system and a 7-DOF master device were employed for a blood-vessel phantom experiment. The experimental results indicated that the haptic feedback and steerable catheter were useful for reducing the procedure time and minimizing  
Figure 16: Reaction force in the three different scenarios for Target 2.  
Figure 17: Reaction force in the three different scenarios for Target 3.  
Figure 15: Reaction force in the three different scenarios for Target 1.  
the damage to the vessel wall. Therefore, applying the steerable catheter and haptic feedback during vascular intervention can reduce the radiation dose to the patient, as well as the vascular perforation. The proposed 5-DOF vascular interventional robot system and 7-DOF master device can assist inexperienced surgeons to easily drive catheters and guidewires in vascular intervention. When the catheter and guidewire must pass through complex blood vessels, manipulating them is difficult for inexperienced surgeons. By using our proposed robot, inexperienced surgeons can easily access difficult vessels with a steerable catheter and haptic feedback. Regarding safety, the insulation problem should be resolved in accordance with IEC60601-1 3.1 ed. Adding more sensors to the final commercial product is not recommended. Instead of using a force/torque sensor, the interaction force can be indirectly measured according to the current change in the motor controller. The application areas of this device are diverse, including chemotherapy for liver cancer and stent installation on the heart.  
Many future studies related to this research can be performed. In recent studies, various sensors and artificial intelligence were applied to surgical robots [24; 25; 26]. In the present study, force measurements using the FT sensor were performed only on the catheters. This is because the catheter contacted most of the vascular line, while only the distal part of the guidewire contacted the vascular line. However, it is necessary to measure the repulsive force induced by the guidewire, particularly when the vascular line is already closed. Recently, research has been conducted on the use of deep neural networks in a vascular interventional robot. Research is also being performed to predict the force generated during vascular intervention according to the motor current data by using deep neural networks instead of an FT sensor. The force measured by an FT sensor can be initially used as the ground truth, but the FT sensor can be removed once the learning process is complete. In the future, it is expected that the degree of autonomy in robotic vascular intervention can be increased. [PERSON] et al. [27] reported vascular intervention path planning using reinforcement learning. Similarly, we plan to apply a reinforced learning algorithm to our vascular intervention robotic system for successful insertion of the catheter into the vascular lines. Precise haptic rendering is another important research topic [28].  
[PERSON] and [PERSON] contributed to the software and experiments, acquired the data, analyzed the data, and wrote the paper; [PERSON] contributed to the paper review and editing; and [PERSON] contributed to the supervision, project administration, and review and editing. All the authors contributed to the paper.  
This work was supported by the Technology Innovation Program (or Industrial Strategic Technology Development Program-Artificial intelligence bio-robot medical convergence project) (20001257, Artificial intelligence algorithm based vascular intervention robot system for reducing radiation exposure and achieving 0.5 mm accuracy) funded by the Ministry of Trade, Industry & Energy (MOTIE, Korea), the Ministry of Health & Welfare (MOHW), Ministry of Science and ICT (MSIT), and the Korea Evaluation Institute of Industrial Technology (KEIT).  
The authors declare no conflict of interest.