Adaptive Clamping Mechanism-based a Novel Slave Manipulator for Endovascular Catheterization

Linshuai Zhang1,4, Shuxiang Guo2*,3*, Huadong Yu4*, Yu Song1, Dapeng Song1

1Faculty of Engineering, Kagawa University, Takamatsu,

Kagawa, Japan

s16d502@stu.kagawa-u.ac.jp

2Key Laboratory of Convergence Medical Engineering System

and Healthcare Technology, The Ministry of Industry and

Information Technology, School of Life Science, Beijing

Institute of Technology, Haidian District, Beijing 100081,

China

3Department of Intelligent Mechanical Systems Engineering,

Kagawa University, Takamatsu, Kagawa 761-0396, Japan

4 School of Mechatronical Engineering,

Changchun University of Science and Technology,

Changchun, Jilin, China

guo@eng.kagawa-u.ac.jp yuhuadong@cust.edu.cn *Corresponding author

Abstract - Robot-assisted catheter systems can obviously reduce the radiation exposure to the surgeon and lessen the fatigue caused by standing for long time in protective clothing. However, few designs have taken the adaptive clamping of a catheter/guidewire manipulator into consideration. Additionally, limited research has been conducted in the damage of the clamping mechanism to the catheter. This paper presents an adaptive clamping mechanism based on the electromagnetic braking for a catheter/guidewire manipulator which can be used in vascular interventional surgeries training system. A valuable contribution is that the proposed clamping structure can adaptively clamping catheters or guidewires of different diameters without replacing the corresponding clamping structure, thus reducing operation time and improving the safety of the surgery. In addition, the force measurement experiments for different clamping objects were conducted. The experimental results show that the contract force can be measured for each bending region of the vascular model without using the corresponding clamping structure. Therefore, the presented clamping structure hinge-based provides important insights into the development of safe and reliable robotic catheter manipulators incorporating effective and convenience clamping for endovascular catheterization. Index Terms -Electromagnetic force, Lossless clamping mechanism, Slave manipulator, Collision protection

I. INTRODUCTION

A report from the American Heart Association (AHA) showed that: the cardiovascular and cerebrovascular diseases remain one of the major causes of mortality in human beings, accounting for 34% of deaths each year, which is a serious threat to human health [1]. Along with the rapid development of the medical technologies, endovascular techniques have been embraced as a minimally-invasive treatment approach for vascular diseases [2]. It has a great application in the world

because of its many advantages, such as smaller incisions, quicker recovery and fewer complications [3]. Nonetheless, the current practice of endovascular procedures is limited by a number of factors including surgeon’s fatigue and physiological tremors, long radiation exposure, limited 3D guiding, and lack of contact force sensing from the endovascular tools. These potential challenges will affect the success of the surgery and have the risk to the surgeon’s health [4]. What’s more, the surgeon must be highly skilled and specialized due to the high risks involved.

In recent years, advances in steerable catheters and development of master-slave robots have aimed to solve the above limitations by keeping the operator away from the radiation source and increasing the precision and stability of catheter motion [2]. Some robot-assisted catheter systems have been developed by the commercial companies. The Amigo TM (Catheter Robotics, Inc., Mount Olive, NJ) remote catheter system (RCS) can position the catheter into the right side of the heart safely and effectively [5]. The Sensei X robotic catheter system (Hansen Medical, Inc., Mountain View, CA, USA) combined 3D technology is a combination of collaborative technologies, which can provide physicians with better accuracy and stability [6, 7]. In addition, many research groups in universities or research institutions are committed to the development of robotic catheter systems. Yogesh et al. [8] proposed a novel remote catheter navigation system with high motion resolution in the axial and radial directions, respectively. It can reduce the physical stress and irradiation to operators under the X-ray 2D fluoroscopy for image guidance. Tavallaei et al. [9] developed a new compact remote catheter system with 3-degrees-of-freedom, which allowed the operator to deftly steer a conventional catheter from a safe place. More recently, an assembly-type and low cost master-slave system with 4-degrees-of-freedom was proposed to reduce radiation

exposure [10]. Some researchers embed force measuring devices to robotic catheter systems in order to reflect the force information more intuitively during the endovascular procedure. A novel master-slave catheter operating system with a load cell and torque sensor was proposed to train the novice to perform the endovascular procedure with force feedback and visual feedback [11]. A compact, cost-effective force-sensing device based on strain gauges was designed to obtain the force information directly without any mechanical transmission [12, 13]. To complete more complex surgeries, Bao et al. [14] developed a novel remote vascular interventional robot based on the cooperation of the catheter manipulator and the guidewire manipulator in series. It can provide precise position control and force information feedback. Currently, the virtual reality (VR)-based technology as an emerging technology was being applied in catheter operating systems [15, 16]. The vasculature [17,18] and catheter [19, 20] models can be built and displayed by the VR simulator. A catheter operating system integrated VR simulator was proposed to improve the skill of catheter manipulation and the coordination of surgeon’s eye-hand for novices [21]. In addition, the collision trauma is still an important theme during the catheterization, despite of the visual assistance. Surgeons often rely on visualization to avoid major vascular collision in the catheterization study. It is difficult to determine whether a vascular collision occurs, due to the absence of depth perception and low definition of the fluoroscopic images [22]. Thus, the surgeon has to observe the deflection of the catheter to determine whether the collision occurred. For this, a novel master manipulator based magnetorheological (MR) fluid was developed to realize the true force feedback [23, 24]. The application of magnetorheological (MR) fluid in the catheter operating system can give surgeons a sense of being like a catheter operating around a patient. Based upon the same principle, a haptic interface on the master side was designed to realize the safety operation consciousness when the catheter tip collided with the blood vessel during the surgery practice [25-28]. On this basis, a speed adjustable mechanism (SAM) installed before the haptic interface device was designed for tissue protection [16]. Guo et al. [29] proposed an operation safety early warning system based on LabView, which can effectively avoid excessive collisions according to the operating force feedback. Nevertheless, because the novices do not have enough experience to quickly regulate the operation of catheter, the fragile vessels (especially cerebral vessels) are in danger of being penetrated by the catheter tip in the event of collision. Thus, based on the theory of collision protection threshold, Zhang et al. [30] reported on a catheter operating system, which prevented vessel puncture provoked by collision thanks to tissue protection. Compared to the traditional vascular interventional surgery, the development of robotic catheter systems can solve many problems such as improving operation precision and stability, reducing radiation exposure and collision trauma, as well as eliminating physiological tremors. However, these robotic systems still have such disadvantage that guidewires or catheters with different diameters need have relative clamping

Fig. 1 The overview of the master-slave robotic catheter system

devices. Replacing clamping device will increase operation time and accident risk. Motivated by such consideration, it is extremely necessary to design a clamping device with uniform force, stable clamping and adjustable clamping range for robotic catheter systems.

In this paper, the novel developed robotic catheter system devotes to provide an adaptive clamping mechanism to catheters or guidewires and realize force measurement, thus reducing the operation time and improving the safety of catheterization. In this system, the clamping structure based on electromagnetic brake is introduced to realize the clamping and relaxation of the catheter. The structure of conical collet can provide big contact area and reliable clamping. In addition, the clamping force can be adjusted by the electromagnetic force, which can prevent catheters from being injured [31]. More importantly, the designed clamping structure can adaptively clamp the catheter or guidewire with different diameters. To sum up, the novel developed robotic catheter system contributes to the adaptive clamping and force measurement in case of replacing catheters or guides with different diameters.

II. STRUCTURE DESIGN OF THE NOVEL CLAMPING MECHANISM

The conceptual diagram of the robotic catheter system, shown in Fig.1, displays the flow chart of the operational process. The robotic catheter system is made up of four subsystems: master subsystem, slave subsystem, communication subsystem and feedback subsystem. A surgeon can operate the master manipulator in a safety place to control the catheter motion on the salve side, thus preventing the surgeon from the radiation of X-ray. Besides, tactile feedback and visual feedback are also very necessary for endovascular procedure.

For these functions, however, the premise is a stable clamping. Insufficient and excessive clamping both can affect the success of operation. Base on such reason, the design of adjustable clamping structure is especially important.

A. Design of The Adaptive Clamping Structure The electromagnetic breaking-based adaptive clamping

structure, shown in Fig.2, consists of a wedge ring, a collet, two hinges and a connector. When the connector is exerted a force from its right side, the two parts of the collet will have the radial movement toward the center under the action of the

Fig. 2 Schematic diagram of the adaptive clamping structurewedge ring and the hinges. The movement stops automatically

until a catheter or guidewire is clamped stably. It does not cause excessive clamping to damage the catheter/guidewire. This adaptive clamping can facilitate the replacement of catheters and guidewires with different diameters (see Fig.2). Compared with the previous clamping structures [23, 31-33], the line-surface clamping with relative direction can make the catheter or guidewire clamping more stable and more uniform. In addition, a layer of silica gel is attached to the clamping surface of the collet, thus further improving the clamping effect due to the increase of static friction coefficient.

B. Principle of The Adaptive Clamping Mechanism The principle diagram of adaptive clamping mechanism,

electromagnetic braking-based, is shown in Fig.3. The specific assembly relations are as follows: the compression spring is fitted around the iron core which connects with the connector by screws. The end of the collet connects with the connector by two hinges, and the front of the collet contacts with the conical surface of the wedge ring. These structures are nested inside the sleeve which is fixed with the electromagnetic chuck. When the power is off state, the collet will clamp the catheter or guidewire under the action of the compression spring. Then the catheter with the whole structure can perform the forward motion, backward motion and rotation. On the contrary, when the power is on state, the collet will close to the iron core side under the action of electromagnetic force which can be adjusted by the current, so as to release the catheter. After that, we can compensate the catheter or guidewire to carry on the subsequent insertion. In addition, the electromagnetic force can also be used to adjust the clamping force in case of energization, thus preventing the catheter from being overly clamped [31]. Furthermore, the adopted wedge ring is removable, which can be controlled by two screws. It can adjust the initial clamping force under the condition of no electromagnetic force, so as to achieve the effect of clamping without damaging the catheter.

Fig. 3 Principle of the adaptive clamping mechanism

III. DESIGN OF THE SLAVE MANIPULATOR

The schematic diagram of the slave manipulator is shown in Fig.4. Fig.4 (a) and (b) describe the front view and the isometric view of the catheter/guidewire manipulator based on the electromagnetic breaking mechanism, respectively. The slave manipulator consists of the force measurement mechanism, electromagnetic clamping mechanism, rotation driving mechanism and insertion driving mechanism [34, 35]. Force measurement mechanism based on a load cell (resolution: 0.0002) is used to measure the haptic force (including tip collision force, viscous force and friction force) [13] between the catheter/guidewire and the blood vessel. Electromagnetic clamping mechanism with the adaptive clamping structure is used for stably clamping the catheter/guidewire to perform the forward motion, retraction and rotation. Rotation driving mechanism and insertion driving mechanism are used for imitating a surgeon’s insertion motion and twisting motion with the catheter/guidewire. Transmission with high accuracy and stability is a necessary condition for successful operation. Therefore, the ball screw and synchronous belt are adopted to transmit axial and radial motion. In order to minimize the influence of contact friction components on the performance of force measurement, two

(a) The front view of the catheter manipulator

(b) The isometric view of the catheter manipulator

Fig. 4 Structure diagram of the slave side

omnibearing bearings are used to support the catheter/guidewire clamping mechanism. In addition, the tightness of the synchronous belt will also be adjusted to the right extent.

IV. PERFORMANCE EVALUATION OF FORCE MEASUREMENT IN

VITRO

For investigating the performance of force measurement, the slave manipulator with catheters/guidewires is used to track a vascular model shown in Fig.5. It is divided into five regions (shown in Fig.5) according to the bending positions. The experimental setup is displayed in Fig.6. The slave manipulator is used for operating a catheter/guidewire to insert into the vascular model and measuring the haptic force. The data collector will acquire the force information and display them on the PC screen. The power source is used to control the electromagnetic clamping mechanism to clamp or release a catheter/guidewire to realize the feed compensation. To verify the adaptability of the clamping structure, one catheter-5Fr and two guidewires (035 and 014) were used to perform the insertion experiment with random tip direction. Their diameters are about 1.67mm, 0.9mm and 0.36mm, respectively.

The results of force measurement are displayed in Fig.7. Fig.7(a) shows the force information when a catheter-1.4mm passes through the vascular model. A, B, C, D and E represent the measuring forces generated by the collision between the tip of the catheter and the five bending regions in the vascular model, respectively. When the tip of catheter passes through a curved area of the vascular model, the measured force will decrease rapidly due to the disappearance of the tip collision force. However, the overall force information will increase with the insertion of catheter due to the increase of friction force between the catheter and the side wall of vascular model. Fig.7(b) displays the force information for a guidewire-0.9mm. The insertion process is the same as the catheter-1.4mm. A, B, C, D and E still represent the measuring forces generated by the collision with related bending regions in the vascular model, respectively. In region C, however, the measured force does not decrease as expected. The reason is that the special curvature of the region C will cause a collision between the bending area of the guidewire tip and the side wall when the guidewire passes through this region, but the tip of the guidewire will collide with the side wall again while the bending area of the tip is away from the collision region. This leads to the continuous increase of measured force due to the existence of tip collision. For the guidewire-0.4mm, the

Fig. 5 A vascular model for in vitro experiments

Fig. 6 The experimental setup for evaluating the performance of force measurement

measured force is shown in Fig.7(c). From the result we can see that, in region A, the force information is almost impossible to detect. Because the wire is too thin, it does not collide with the vascular model. In region E, the measured force does not increase as expected. When the guidewire passes through region E, the tip and tip bend of guidewire do not collide with the side wall of region E. It is caused by the small diameter of the guide wire and the bending shape of the tip. Therefore, the measured force will decrease due to the disappearance of tip collision force and the reduction of friction force. During the actual operation, the feedback force information can assist surgeons to judge whether the catheter safely passes through the curved area of blood vessels. Especially for cerebral vessels, the smaller the blood vessels can bear the smaller the collision force. Even a highly skilled surgeon can hardly feel the impact of a tiny collision because of the limits of human feeling. Therefore, a more precise measurement device and detection method is particularly important in the vascular interventional surgery.

(a) The measured force for the catheter-5Fr

(b) The measured force for the guidewire-035

(c) The measured force for the guidewire-014

Fig. 7 Force measurement results of the slave manipulator

V. CONCLUSION AND FUTURE WORK

In this paper, the clamping mechanism based on the electromagnetic braking for a novel catheter manipulator of robot-assisted catheterization system is proposed. The proposed clamping mechanism can offer a fast response and lossless clamping due to the big clamping contact area. The significant advantage of the proposed design is the adaptive clamping. The hinge structure is used as a support point for clamping changes. It can provide a stable clamping for catheters or guidewires of different diameters without replacing the clamping structure, thus reducing the operation time and ensuring the accuracy of force measurement (the accuracy of measurement may be influenced by frequent replacement of clamping structure). And the force measurement experiments for different clamping objects were carried out. The experimental results show that the contract force can also be detected for each bending region without using the corresponding clamping structure. The novel clamping structure can adaptively clamp catheters or guidewires of different diameters with the function of force measurement. Therefore, the presented clamping structure hinge-based is of great significance for improving the convenience of the surgery.

In the future work, some experimental tests for the whole system will be conducted for contributing to development of high intelligence and high precision robot-assisted catheterization system.

ACKNOWLEDGMENT

This research is partly supported by National High Tech. Research and Development Program of China (No.2015AA043202), and SPS KAKENHI Grant Number 15K2120.

REFERENCES

[1] D. Lloyd-Jones, R. Adams, T. Brown, et al., “Executive summary: heart disease and stroke statistics-2010 update: a report from the American Heart Association”, Circulation, vol.121, pp.948-954, 2010.

[2] H. Rafii-Tari, C. Payne, G. Yang, “Current and Emerging Robot-Assisted Endovascular Catheterization Technologies: A Review”, Annals of Biomedical Engineering, vol.42, no. 4, pp.697-715, 2013.

[3] J. Guo, S. Guo, T. Tamiya, H. Hirata, H. Ishihara, “A virtual reality-based method of decreasing transmission time of visual feedback for a teleoperative robotic catheter operating system”, The International of Medical Robotics and Computer Assisted Surgery, vol.12, no.1, pp.32-45, 2016.

[4] A. Mohapatra, R. Greenberg, T. Mastracci, M. Eagleton, B. Thornsberry, “Radiation exposure to operating room personnel and patients during endovascular procedures”, Journal of Vascular Surgery, vol.58, no.3, pp.702-709, 2013.

[5] E. M. Khan, W. Frumkin, G. Andre Ng, S. Neelagaru, F. M. Abi-Samra et al., “First experience with a novel robotic remote catheter system: AmigoTM mapping trial”, Journal of Interventional Cardiac Electrophysiology, vol.37, no.2, pp.124-129, 2013.

[6] S. Willems, D. Steven, H. Servatius, B. A. Hoffmann, I. Drewitz et al., “Persistence of Pulmonary Vein Isolation After Robotic Remote-Navigated Ablation for Atrial Fibrillation and its Relation to Clinical Outcome”, Journal Cardiovascular Electrophysiology, vol.21, no.10, pp.1079-1084, 2010.

[7] P. Hlivák, H. Mlčochová, P. Peichl, R. Čihák, D. Wichterle, J. Kautzner, “Robotic Navigation in Catheter Ablation for Paroxysmal Atrial Fibrillation: Midterm Efficacy and Predictors of Postablation Arrhythmia Recurrences”, Journal Cardiovascular Electrophysiology, vol.22, no.5, pp.534-540, 2011.

[8] T. Yogesh, S. Jeffrey, W. David, D. Maria, “Design and Performance Evaluation of a Remote Catheter Navigation System”, IEEE transactions on biomedical engineering, vol.56, no.7, pp.1901-1908, 2009

[9] M. Tavallaei, D. Gelman, M. Lavdas, A. Skanes, D. Jones, J. Bax, M. Drangova, “Design, development and evaluation of a compact telerobotic catheter navigation system”, The International Journal of Medical Robotics and Computer Assisted Surgery, vol.12, no.3, pp.442-452, 2016.

[10] H. Cha, B. Yi, J. Won, “An assembly-type master-slave catheter and guidewire driving system for vascular intervention”, Journal of Engineering in Medicine, vol.231, no.1, pp.69-79, 2017.

[11] J. Guo, S. Guo, N. Xiao, X. Ma, S. Yoshida, T. Tamiya, M. Kawanishi, “A novel robotic catheter system with force and visual feedback for vascular interventional surgery”, International Journal of Mechatronics and Automation, vol.2, no.1, pp. 15-24, 2012.

[12] L. Zhang, S. Guo, H. Yu, Y. Song, “Performance evaluation of a strain-gauge force sensor for a haptic robot-assisted catheter operating system”, Microsystem Technologies, vol.23, no.10, 5041-5050, 2017.

[13] Y. Zhao, S. Guo, N. Xiao, Y. Wang, Y. Li, Y. Jiang, “Operating force information on-line acquisition of a novel slave manipulator for vascular interventional surgery”, Biomedical Microdevices, 2018. https://doi.org/10.1007/s10544-018-0275-7

[14] X. Bao, S. Guo, N. Xiao, Y. Li, C. Yang, Y. Jiang, “A cooperation of catheters and guidewires-based novel remote-controlled vascular interventional robot”, Biomedical Microdevices, 2018. https://doi.org/10.1007/s10544-018-0261-0

[15] C. Zhou, L. Xie, X. Shen, M. Luo, Z. Wu, L. Gu, “Cardiovascular-interventional-surgery virtual training platform and its preliminary evaluation”, The International Journal of Medical Robotics and Computer Assisted Surgery, vol.11, pp.375-387, 2015.

[16] Y. Wang, S. Guo, Y. Li, T. Tamiya, Y. Song, “Design and evaluation of safety operation VR training system for robotic catheter surgery”, Medical & Biological Engineering & Computing, vol.56, no.1, pp.25-35, 2017.

[17] E. Johnson, Y. Zhang, K. Shimada, “Estimating an equivalent wall-thickness of a cerebral aneurysm through surface parameterization and a non-linear spring system”, International Journal for Numerical Methods in Biomedical Engineering, vol.27, no.7, pp.1054-1072, 2011.

[18] D. Zhang, T. Wang, D. Liu, G. Lin, “Vascular deformation for vascular interventional surgery simulation”, International Journal of Medical Robotics and Computer Assisted Surgery, vol.6, no.2, pp.171-177, 2010.

[19] J. Lenoir, S. Cotin, C. Duriez, P. Neumann, “Interactive physically-based simulation of catheter and guidewire”, Computers & Graphics, vol.30,

no.3, pp.416-422, 2006. [20] W. Tang, T. Wan, D. A. Gould, T. How, N. W. John, “A Stable and

Real-Time Nonlinear Elastic Approach to Simulating Guidewire and Catheter Insertions Based on Cosserat Rod”, IEEE Transactions on Biomedical Engineering, vol.59, no.8, pp.2211-2218, 2012.

[21] Y. Wang, S. Guo, T. Tamiya, H. Hirata, H. Ishihara, X. Yin, “A virtual-reality simulator and force sensation combined catheter operation training system and its preliminary evaluation”, International Journal of Medical Robotics and Computer Assisted Surgery, vol.13, no.3, pp.e1769, 2017.

[22] C. J.Payne, H. Rafii-Tari and G. Yang, “A Force Feedback System for Endovascular Catheterisation”, Proceedings of the 2012 IEEE/RSJ International Conference on Intelligent Robots and Systems, pp.1298-1304, Portugal, 2012.

[23] J. Guo, S. Guo, L. Shao, P. Wang, Q. Gao, “Design and performance evaluation of a novel robotic catheter system for vascular interventional surgery”, Microsystem Technologies, vol.22, no.9, pp.2167-2176, 2015.

[24] J. Guo, S. Guo, Y. Yu, “Design and characteristics evaluation of a novel teleoperated robotic catheterization system with force feedback for vascular interventional surgery”, Biomedical Microdevices, 2016. https://doi.org/10.1007/s10544-016-0100-0

[25] X. Yin, S. Guo, H. Hirata, H. Ishihara, “Design and experimental evaluation of teleoperated haptic robot-assisted catheter operating system”, Journal of Intelligent Material Systems and Structures, vol.27, no.1, pp.3–16, 2014.

[26] X. Yin, S. Guo, N. Xiao, T. Tamiya, “Safety Operation Consciousness Realization of a MR Fluids-based Novel Haptic Interface for Teleoperated Catheter Minimally Invasive Neuro Surgery”, IEEE/ASME Transactions on Mechatronics, vol.21, no.2, pp.1043-1054, 2015.

[27] Y. Song, S. Guo, X. Yin, L. Zhang, Y. Wang, H. Hirata and H. Ishihara, “Design and Performance Evaluation of a Haptic Interface based on MR Fluids for Endovascular Tele-surgery”, Microsystem Technologies, vol.24, no.2, pp.909-918, 2018.

[28] Y. Song, S. Guo, L. Zhang and X. Yin, “MR Fluid Interface of Endovascular Catheterization Based on Haptic Sensation”, Proceedings of the 2016 IEEE International Conference on Mechatronics and Automation, pp. 454-458, China, 2016.

[29] J. Guo, X. Jin, S. Guo, “Study of the Operational Safety of a Vascular Interventional Surgical Robotic System”, Micromachines, vol.9, no.3, 2018.

[30] L. Zhang, S. Guo, H. Yu, Y. Song, T. Tamiya, H. Hirata, H. Ishihara, “Design and performance evaluation of collision protection-based safety operation for a haptic robot-assisted catheter operating system”, Biomedical Microdevices, 2018. https://doi.org/10.1007/s10544-018-0266-8

[31] L. Zhang, S. Guo, H. Yu, Y. Song, “Design and Principle Analysis for Electromagnetic Brake Clamping Mechanism of a Novel Slave Manipulator”, Proceedings of the 2016 IEEE International Conference on Mechatronics and Automation, pp. 490-495, China, 2016.

[32] N. Xiao, J. Guo, S. Guo, T. Tamiya, “A robotic catheter system with real-time force feedback and monitor”, Journal of Australasian Physical and Engineering Sciences in Medicine, vol.35, no.3, pp.283-289, 2012.

[33] J. Guo, S. Guo, N. Xiao, X. Ma, S. Yoshida, T. Tamiya, M. Kawanishi, “A novel robotic catheter system with force and visual feedback for vascular interventional surgery”, International Journal of Mechatronics and Automation, vol.2, no.1, pp.15-24, 2012.

[34] L. Zhang, S. Guo, H. Yu, S. Gu, Y. Song, M. Yu, “Electromagnetic Braking-based Collision Protection of a Novel Catheter Manipulator”, Proceedings of the 2017 IEEE International Conference on Mechatronics and Automation, pp.1726-1731, China, 2017.

[35] X. Bao, S. Guo, N. Xiao, Y. Wang, M. Qin, Y. Zhao, C. Xu and W. Peng, “Design and Evaluation of a Novel Guidewire Navigation Robot”, Proceedings of the 2016 IEEE International Conference on Mechatronics and Automation, pp. 431-436, China, 2016.