According to a report from the American Heart Association (AHA), cardiovascular and cerebrovascular diseases have become one of the three major causes (heart disease, stroke and vascular diseases) of death in human beings. With the rapid development of medical technologies, vascular interventional surgery (VIS), due to its smaller incisions, quicker recovery and fewer complications, has become the common practice for diagnosing and treating various cardiac and vascular diseases. Nonetheless, some potential challenges also have been introduced in. The surgeon’s fatigue and physiological tremors will affect the success of the surgery, long radiation exposure has the risk to the surgeon’s health. What’s more, the surgeon must be highly skilled and specialized due to the high risks involved.
To solve these disadvantages mentioned above, researchers combine the robot-assisted technology with VIS to develop many kinds of robot-assisted catheter systems for endovascular procedures.
1) The current system doesn’t consider the adaptive, stable and lossless clamping for the catheter/guidewire, and effective force feedback during the catheterization remains unrealized.
2) No collision protection function in the current system, thus increasing the incidence of medical accidents.
3) The current system doesn’t consider the collaborative propulsion of the catheter and guide wire. The single operation will affect operation time and success rate.
3.Research purposes and approaches
1) Focus on the lossless clamping of the catheter and design a new force measuring unit to realize the effective force feedback.
2) Add the collision protection mechanism in the slave manipulator, so as to effectively avoid vessel puncture caused by system malfunction or human error.
3) Realize the collaborative propulsion function of the catheter and guide wire, thus reducing the operation time and improving the success rate of the task in complex surgeries.
Topic 1: Design a novel type of slave side with effective force feedback.
Topic 2: Realization of the collision protection function on the slave manipulator.
Topic 3: Performance evaluation of collaborative motion for the catheter and guide wire in the novel robotic catheter system.
5. Conclusions and future work
In this paper, the novel robot-assisted catheter system is developed to augment the surgeon’s actions and improve the safe operation of catheterization.
1) The novel robotic catheter system is based on two rotary encoders to transmit and feedback the motion information. The experimental results of bilateral operation show that the maximum absolute transmission error in axial and radial directions are 0.79mm and 1.7°, respectively.
2) The application of the haptic interface based on magnetorheological (MR) fluid and high-precision force sensor makes the collision warning in haptic cues possible. The accuracy of the measured force has important influence on the safety of surgeries. The results of the step response experiment show that the hysteresis for force measurement is generated, with an average value of 8.89mN. However, the hysteresis is very small in the whole load range, particularly at lower load.
3) The collision protection mechanism (CPM) based on electromagnetic braking is proposed to realize the vascular tissue protection. Based on the results of these evaluation experiments, the CPM equipped the robot-assisted catheter system has made great contribution to remit the collision trauma during the endovascular catheterization.
4) In addition, we use two slave manipulators to operate the catheter and guidewire respectively to complete the complex surgical operation, reduce the operation time and improve the success rate of the task.
For widespread use of robot-assisted endovascular catheterization systems, the development of high intelligence and high-precision robotic catheter system incorporating natural manipulation skills is a potential area for future research.