Systematic review on visual aid technologies for surgical assistant robotic devices. PROGRESS IN BIOMEDICAL ENGINEERING (BRISTOL, ENGLAND) 2025;7:022006. [PMID: 39999565 DOI: 10.1088/2516-1091/adba20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

This review comprehensively analyzes the modern literature on including visual aids in diverse surgical assistant robotic systems. The review considered a deep analysis of diverse technical and scientific sources that provide precise information on how the more recent surgical systems, especially those considering robotic devices, perform automatic operations on patients. The search procedure and the corresponding analytics considered only those conditions where vision systems played a significant role in the surgical procedure, despite the type of end-effector and if only position or force were used as part of the feedback analysis. This review is organized considering the robot configuration, the type of end-effector, the vision systems considered for those cases, and the associated control actions, which must include the acquired image or video. The study analyzes the key contributions of the published cases. It provides a critical description of the advantages and shortcomings of the technological implementation of vision systems in surgical robotic devices. Finally, this review provides a general prospective view of ongoing research on vision aids for surgical robotic systems, which will become an ordinary actor in future surgical systems.

An advanced robotic system incorporating haptic feedback for precision cardiac ablation procedures

This study introduces an innovative master-slave cardiac ablation catheter robot system that employs magnetorheological fluids. The system incorporates magnetorheological fluid to enable collision detection through haptic feedback, thereby enhancing the operator's situational awareness. A modular clamping and propulsion mechanism has been engineered for the ablation catheter, facilitating omnidirectional operation and force feedback within the cardiac cavity. To evaluate the proposed system, an in vitro experiment was performed. Results from the experiment indicate that the system demonstrates high motion transmission accuracy. Furthermore, the system effectively alerts operators to potential collisions, enabling swift catheter position adjustments, minimizing the risk of vascular perforation, and ultimately enhancing the overall safety and efficiency of the procedure.

Multi-axis robotic forceps with decoupled pneumatic actuation and force sensing for cochlear implantation

Delicate manual microsurgeries rely on sufficient hands-on experience for safe manipulations. Automated surgical devices can enhance the effectiveness, but developing high-resolution, multi-axis force-sensing devices for micro operations remains challenging. In this study, a 6-axis force-sensing pneumatic forceps with a serial-parallel robotic platform for cochlear implantation is developed. The forceps features a curved body shape embedded with parallel and inclined fiber Bragg grating sensors for 6-axis force sensing, and a pneumatic gripper with decoupled actuation is located at its end for actively grasping and releasing the electrode array. The robotic platform comprises a customized spherical parallel mechanism and a robotic arm, which can provide independent 3-DOF rotations and 3-DOF translations. The feasibility of the developed robotic forceps is validated through cadaveric studies on a temporal bone and a human cadaveric head. In summary, the robotic forceps provides a decoupled mechanism for pneumatic actuation and force sensing, further demonstrating its potential for force interaction and stable operation during robotic microsurgery.

An intuitive guidewire control mechanism for robotic intervention

PURPOSE

Teleoperated Interventional Robotic systems (TIRs) are developed to reduce radiation exposure and physical stress of the physicians and enhance device manipulation accuracy and stability. Nevertheless, TIRs are not widely adopted, partly due to the lack of intuitive control interfaces. Current TIR interfaces like joysticks, keyboards, and touchscreens differ significantly from traditional manual techniques, resulting in a shallow, longer learning curve. To this end, this research introduces a novel control mechanism for intuitive operation and seamless adoption of TIRs.

METHODS

An off-the-shelf medical torque device augmented with a micro-electromagnetic tracker was proposed as the control interface to preserve the tactile sensation and muscle memory integral to interventionalists' proficiency. The control inputs to drive the TIR were extracted via real-time motion mapping of the interface. To verify the efficacy of the proposed control mechanism to accurately operate the TIR, evaluation experiments using industrial grade encoders were conducted.

RESULTS

A mean tracking error of 0.32 ± 0.12 mm in linear and 0.54 ± 0.07° in angular direction were achieved. The time lag in tracking was found to be 125 ms on average using pade approximation. Ergonomically, the developed control interface is 3.5 mm diametrically larger, and 4.5 g. heavier compared to traditional torque devices.

CONCLUSION

With uncanny resemblance to traditional torque devices while maintaining results comparable to state-of-the-art commercially available TIRs, this research successfully provides an intuitive control interface for potential wider clinical adoption of robot-assisted interventions.

Development of an Intuitive Interface With Haptic Enhancement for Robot-Assisted Endovascular Intervention

Robot-assisted endovascular intervention has the potential to reduce radiation exposure to surgeons and enhance outcomes of interventions. However, the success and safety of endovascular interventions depend on surgeons' ability to accurately manipulate endovascular tools such as guidewire and catheter and perceive their safety when cannulating patient's vessels. Currently, the existing interventional robots lack a haptic system for accurate force feedback that surgeons can rely on. In this paper, a haptic-enabled endovascular interventional robot was developed. We proposed a dynamic hysteresis compensation model to address the challenges of hysteresis and nonlinearity in magnetic powder brake-based haptic interface, which were used for providing high-precision and higher dynamic range haptic perception. Also, for the first time, a human perceptual-based haptic enhancement model and safety strategy were integrated with the custom-built haptic interface for enhancing sensation discrimination ability during robot-assisted endovascular interventions. This can effectively amplify even subtle changes in low-intensity operational forces such that surgeons can better discern any vessel-tools interaction force. Several experimental studies were performed to show that the haptic interface and the kinesthetic perception enhancement model can enhance the transparency of robot-assisted endovascular interventions, as well as promote the safety awareness of surgeon.

Design and Evaluation of Augmented Reality-Enhanced Robotic System for Epidural Interventions

The epidural injection is a medical intervention to inject therapeutics directly into the vicinity of the spinal cord for pain management. Because of its proximity to the spinal cord, imprecise insertion of the needle may result in irreversible damage to the nerves or spinal cord. This study explores enhancing procedural accuracy by integrating a telerobotic system and augmented reality (AR) assistance. Tele-kinesthesia is achieved using a leader-follower integrated system, and stable force feedback is provided using a novel impedance-matching force rendering approach. In this domain, augmented reality employs a magnetic-tracker-based approach for real-time 3D model projection onto the patient's body, aiming to augment the physician's visual field and improve needle insertion accuracy. Preliminary results indicate that our AR-enhanced robotic system may reduce the cognitive load and improve the accuracy of ENI, highlighting the promise of AR technologies in complex medical procedures. However, further studies with larger sample sizes and more diverse clinical settings must comprehensively validate these findings. This work lays the groundwork for future research into integrating AR into medical robotics, potentially transforming clinical practices by enhancing procedural safety and efficiency.

Remote-Controlled and Teleoperated Systems: Taking Robotic Image Guided Interventions to the Next Stage

Remote-controlled and teleoperated robotic systems mark transformative advancements in interventional radiology (IR), with the potential to enhance precision, reduce radiation exposure, and expand access to care. By integrating robotic devices with imaging guidance, these systems enable precise instrument placement and navigation, thereby improving the efficacy and safety of minimally invasive procedures. Remote-controlled and teleoperated robotic systems-operated by clinicians using control interfaces from within or adjacent to the procedure room-are being adopted for both percutaneous and endovascular interventions. In contrast, although their application is still experimental, teleoperation over long distances hold promise for extending IR services to medically underserved areas by enabling remote procedures. This review details the definitions and components of remote-controlled and teleoperated robotic systems in IR, examines their clinical applications in percutaneous and endovascular interventions, and discusses relevant challenges and future directions for their incorporation into IR practices.

A Hydraulic Haptic Actuator for Simulation of Cardiac Catheters

This article presents a haptic actuator made of silicone rubber to provide both passive and active haptic forces for catheter simulations. The haptic actuator has a torus outer shape with an ellipse-shaped inside chamber which is actuated by hydraulic pressure. Expansion of the chamber by providing positive pressure can squeeze the inside passage to resist the catheter traveling through. Further expansion can hold and push back the catheter in the axial direction to render active haptic forces. The size of the catheter passage is increased by providing negative pressure to the chamber, allowing various diameters of the actual medical catheters to be used and exchanged during the simulation. The diameter of the catheter passage can be enlarged up to 1.6 times to allow 5 to 7 Fr (1 Fr = 1/3 mm) medical catheters to pass through. Experiment results show that the proposed haptic actuator can render 0 to 2.0 N passive feedback force, and a maximum of 2.0 N active feedback force, sufficient for the cardiac catheter simulation. The haptic actuator can render the commanded force profile with 0.10 N RMS (root-mean-squares) and 10.51% L2-norm relative errors.

Modeling and experimental study of the intervention forces between the guidewire and blood vessels

A profound investigation of the interaction mechanics between blood vessels and guidewires is necessary to achieve safe intervention. An interactive force model between guidewires and blood vessels is established based on cardiovascular fluid dynamics theory and contact mechanics, considering two intervention phases (straight intervention and contact intervention at a corner named "J-vessel"). The contributing factors of the force model, including intervention conditions, guidewire characteristics, and intravascular environment, are analyzed. A series of experiments were performed to validate the availability of the interactive force model and explore the effects of influential factors on intervention force. The intervention force data were collected using a 2-DOF mechanical testing system instrumented with a force sensor. The guidewire diameter and material were found to significantly impact the intervention force. Additionally, the intervention force was influenced by factors such as blood viscosity, blood vessel wall thickness, blood flow velocity, as well as the interventional velocity and interventional mode. The experiment of the intervention in a coronary artery physical vascular model confirms the practicality validation of the predicted force model and can provide an optimized interventional strategy for vascular interventional surgery. The enhanced intervention strategy has resulted in a considerable reduction of approximately 21.97 % in the force exerted on blood vessels, effectively minimizing the potential for complications associated with the interventional surgery.

Kirchhoff rod-based three-dimensional dynamical model and real-time simulation for medical-magnetic guidewires

BACKGROUND AND OBJECTIVE

Magnetic guidewire, fabricated from hard-magnetic soft composites, has recently emerged as an appropriate candidate for magnetic actuation systems to perform intravascular surgical navigation, owing to its elastic, magnetically steerable properties and good interphase with biological tissues. A suitable and efficient mathematical model for the magnetic guidewire is essential in the system to execute remote manipulation and active control.

METHODS

This paper presents a real-time Kirchhoff rod-based dynamical modeling approach, the magneto-elastic rod model, to simulate magnetic guidewire, which provides accurate simulations for two- and three-dimensional dynamic deflections induced by external magnetic fields and obtains deformed guidewire shapes in quasi-static status.

RESULTS

The proposed model is capable of describing the intrinsic principles of elastic body actuation by torques generated from the hard-magnetic soft matrix. The effectiveness of the developed model is validated, and the real-time simulation application is conducted via the semi-implicit numerical integration method.

CONCLUSIONS

It has been shown that the presented dynamical model captures large nonlinear deformations and transient responses of the magnetic guidewire in an imitated human blood environment, which could offer robust support for the construction of a simulated magnetically driven surgical system.

Learning-Based Multimodal Information Fusion and Behavior Recognition of Vascular Interventionists' Operating Skills

The operating skills of vascular interventionists have an important impact on the effect of surgery. However, current research on behavior recognition and skills learning of interventionists' operating skills is limited. In this study, an innovative deep learning-based multimodal information fusion architecture is proposed for recognizing and analyzing eight common operating behaviors of interventionists. An experimental platform integrating four modal sensors is used to collect multimodal data from interventionists. The ANOVA and Manner-Whitney tests is used for relevance analysis of the data. The analysis results demonstrate that there is almost no significant difference ( p <0.001) between the actions related to the unimodal data, which cannot be used for accurate behavior recognition. Therefore, a study of the fusion architecture based on the existing machine learning classifier and the proposed deep learning fusion architecture is carried out. The research findings indicate that the proposed deep learning-based fusion architecture achieves an impressive overall accuracy of 98.5%, surpassing both the machine learning classifier (93.51%) and the unimodal data (90.05%). The deep learning-based multimodal information fusion architecture proves the feasibility of behavior recognition and skills learning of interventionist's operating skills. Furthermore, the application of deep learning-based multimodal fusion technology of surgeon's operating skills will help to improve the autonomy and intelligence of surgical robotic systems.

Toward a novel soft robotic system for minimally invasive interventions

PURPOSE

During minimally invasive surgery, surgeons maneuver tools through complex anatomies, which is difficult without the ability to control the position of the tools inside the body. A potential solution for a substantial portion of these procedures is the efficient design and control of a pneumatically actuated soft robot system.

METHODS

We designed and evaluated a system to control a steerable catheter tip. A macroscale 3D printed catheter tip was designed to have two separately pressurized channels to induce bending in two directions. A motorized hand controller was developed to allow users to control the bending angle while manually inserting the steerable tip. Preliminary characterization of two catheter tip prototypes was performed and used to map desired angle inputs into pressure commands.

RESULTS

The integrated robotic system allowed both a novice and a skilled surgeon to position the steerable catheter tip at the location of cylindrical targets with sub-millimeter accuracy. The novice was able to reach each target within ten seconds and the skilled surgeon within five seconds on average.

CONCLUSION

This soft robotic system enables its user to simultaneously insert and bend the pneumatically actuated catheter tip with high accuracy and in a short amount of time. These results show promise concerning the development of a soft robotic system that can improve outcomes in minimally invasive interventions.

A Novel Master-Slave Interventional Surgery Robot with Force Feedback and Collaborative Operation

In recent years, master-slave vascular robots have been developed to address the problem of radiation exposure during vascular interventions for surgeons. However, the single visual feedback reduces surgeon immersion and transparency of the system. In this work, we have developed a haptic interface based on the magnetorheological fluid (MRF) on the master side. The haptic interface can provide passive feedback force with high force fidelity and low inertia. Additionally, the manipulation of the master device does not change the operating posture of traditional surgery, which allows the surgeon to better adapt to the robotic system. For the slave robot, the catheter and guidewire can be navigated simultaneously which allows the two degrees of action on the catheter and axial action of a guidewire. The resistance force of the catheter navigation is measured and reflected to the user through the master haptic interface. To verify the proposed master-slave robotic system, the evaluation experiments are carried out in vitro, and the effectiveness of the system was demonstrated experimentally.

A novel catheter interaction simulating method for virtual reality interventional training systems

Endovascular robotic systems have been applied in robot-assisted interventional surgery to improve surgical safety and reduce radiation to surgeons. However, this surgery requires surgeons to be highly skilled at operating vascular interventional surgical robot. Virtual reality (VR) interventional training systems for robot-assisted interventional surgical training have many advantages over traditional training methods. For virtual interventional radiology, simulation of the behaviors of surgical tools (here mainly refers to catheter and guidewire) is a challenging work. In this paper, we developed a novel virtual reality interventional training system. This system is an extension of the endovascular robotic system. Because the master side of this system can be used for both the endovascular robotic system and the VR interventional training system, the proposed system improves training and reduces the cost of education. Moreover, we proposed a novel method to solve catheterization modeling during the interventional simulation. Our method discretizes the catheter by the collision points. The catheter between two adjacent collision points is treated as thin torsion-free elastic rods. The deformation of the rod is mainly affected by the force applied at the collision points. Meanwhile, the virtual contact force is determined by the collision points. This simplification makes the model more stable and reduces the computational complexity, and the behavior of the surgical tools can be approximated. Therefore, we realized the catheter interaction simulation and virtual force feedback for the proposed VR interventional training system. The performance of our method is experimentally validated.

Design and evaluation of vascular interventional robot system for complex coronary artery lesions

At present, most vascular intervention robots cannot cope with the more common coronary complex lesions in the clinic. Moreover, the lack of effective force feedback increases the risk of surgery. In this paper, a vascular interventional robot that can collaboratively deliver multiple interventional instruments has been developed to assist doctors in the operation of complex lesions. Based on the doctor's skills and the delivery principle of interventional instruments, the main and slave manipulators of the robot system are designed. Haptic force feedback is generated through resistance measuring mechanism and active drag system. In addition, a force feedback control strategy based on force-velocity mapping is proposed to realize the continuous change of force and avoid vibration. The proposed robot system was evaluated through a series of experiments. The experimental results show that the system can accurately measure the delivery resistance of interventional instruments, and provide haptic force feedback to doctors. The capability of the system to collaboratively deliver multiple interventional instruments is effective. Therefore, it can be considered that the robot system is feasible and effective.

Technical and Clinical Progress on Robot-Assisted Endovascular Interventions: A Review

Prior methods of patient care have changed in recent years due to the availability of minimally invasive surgical platforms for endovascular interventions. These platforms have demonstrated the ability to improve patients' vascular intervention outcomes, and global morbidities and mortalities from vascular disease are decreasing. Nonetheless, there are still concerns about the long-term effects of exposing interventionalists and patients to the operational hazards in the cath lab, and the perioperative risks that patients undergo. For these reasons, robot-assisted vascular interventions were developed to provide interventionalists with the ability to perform minimally invasive procedures with improved surgical workflow. We conducted a thorough literature search and presented a review of 130 studies published within the last 20 years that focused on robot-assisted endovascular interventions and are closely related to the current gains and obstacles of vascular interventional robots published up to 2022. We assessed both the research-based prototypes and commercial products, with an emphasis on their technical characteristics and application domains. Furthermore, we outlined how the robotic platforms enhanced both surgeons' and patients' perioperative experiences of robot-assisted vascular interventions. Finally, we summarized our findings and proposed three key milestones that could improve the development of the next-generation vascular interventional robots.

Discrete soft actor-critic with auto-encoder on vascular robotic system

Instrument delivery is critical part in vascular intervention surgery. Due to the soft-body structure of instruments, the relationship between manipulation commands and instrument motion is non-linear, making instrument delivery challenging and time-consuming. Reinforcement learning has the potential to learn manipulation skills and automate instrument delivery with enhanced success rates and reduced workload of physicians. However, due to the sample inefficiency when using high-dimensional images, existing reinforcement learning algorithms are limited on realistic vascular robotic systems. To alleviate this problem, this paper proposes discrete soft actor-critic with auto-encoder (DSAC-AE) that augments SAC-discrete with an auxiliary reconstruction task. The algorithm is applied with distributed sample collection and parameter update in a robot-assisted preclinical environment. Experimental results indicate that guidewire delivery can be automatically implemented after 50k sampling steps in less than 15 h, demonstrating the proposed algorithm has the great potential to learn manipulation skill for vascular robotic systems.

Kinetics Analysis and ADRC-Based Controller for a String-Driven Vascular Intervention Surgical Robotic System

Vascular interventional surgery is a typical method for diagnosing and treating cardio-cerebrovascular diseases. However, a surgeon is exposed to significant X-radiation exposure when the operation is conducted for a long period of time. A vascular intervention surgical robotic system for assisting the surgeon is a promising approach to address the aforementioned issue. When developing the robotic system, a high displacement accuracy is crucial, and this can aid in enhancing operating efficiency and safety. In this study, a novel kinetics analysis and active disturbance rejection control (ADRC)-based controller is proposed to provide high accuracy for a string-driven robotic system. In this controller, kinetics analysis is initially used to improve the accuracy affected by the inner factors of the slave manipulator. Then, the ADRC controller is used to further improve the operating accuracy of the robotic system. Finally, the proposed controller is evaluated by conducting experiments on a vascular model. The results indicate maximum steady errors of 0.45 mm and 6.67°. The experimental results demonstrate that the proposed controller can satisfy the safety requirements of the string-driven robotic system.

Remote vascular interventional surgery robotics: a literature review

Vascular interventional doctors are exposed to radiation hazards during surgery and endure high work intensity. Remote vascular interventional surgery robotics is a hot research field, in which researchers aim to not only protect the health of interventional doctors, but to also improve surgical accuracy and efficiency. However, the current vascular interventional robots have numerous shortcomings, such as poor haptic feedback, few compatible surgeries and instruments, and cumbersome maintenance and operational procedures. Nevertheless, vascular interventional surgery combined with robotics provides more cutting-edge directions, such as Internet remote surgery combined with 5G network technology and the application of artificial intelligence in surgical procedures. To summarize the developmental status and key technical points of intravascular interventional surgical robotics research, we performed a systematic literature search to retrieve original articles related to remote vascular interventional surgery robotics published up to December 2020. This review, which includes 113 articles published in English, introduces the mechanical and structural characteristics of various aspects of vascular interventional surgical robotics, discusses the current key features of vascular interventional surgical robotics in force sensing, haptic feedback, and control methods, and summarizes current frontiers in autonomous surgery, long-distance robotic telesurgery, and magnetic resonance imaging (MRI)-compatible structures. On the basis of summarizing the current research status of remote vascular interventional surgery robotics, we aim to propose a variety of prospects for future robotic systems.

An Endovascular Catheterization Robotic System Using Collaborative Operation with Magnetically Controlled Haptic Force Feedback

Robot-assisted technology is often used to perform endovascular catheterization surgeries, which generally depend on the flexible operability and the accurate force feedback of a robotic system. In this paper, an endovascular catheterization robotic system (ECRS) was developed to improve collaborative operation and haptic force feedback. A couple of operating handles were designed to maximize the use of the natural operations of surgeons on the master side, which is a flexible and ergonomic device. A magnetically controlled haptic force feedback structure is proposed based on hydrogel and solid magnetorheological (MR) fluid to offer a sense of haptic feedback to operators; this has potential influence on the field of force feedback. In addition, a unique tremor-reduction structure is introduced to enhance operating safety. Tracking performance experiments and in vitro experiments were conducted to evaluate the performance of the developed ECRS. According to these experimental results, the average translation-tracking error is 0.94 mm, and the average error of rotation is 0.89 degrees. Moreover, in vitro experiments demonstrated that haptic feedback has the advantage of reducing workload and shortening surgery completion time. The developed ECRS also has the benefits of inspiring other researchers to study collaborative robots and magnetically controlled feedback.

ADRC-Based Control Method for the Vascular Intervention Master-Slave Surgical Robotic System

In vascular interventional surgery, surgeons operate guidewires and catheters to diagnose and treat patients with the assistance of the digital subtraction angiography (DSA). Therefore, the surgeon will be exposed to X-rays for extended periods. To protect the surgeon, the development of a robot-assisted surgical system is of great significance. The displacement tracking accuracy is the most important issue to be considered in the development of the system. In this study, the active disturbance rejection control (ADRC) method is applied to guarantee displacement tracking accuracy. First, the core contents of the proportional–integral–derivative (PID) and ADRC methods are analyzed. Second, comparative evaluation experiments for incremental PID and ADRC methods are presented. The results show that the ADRC method has better performance of than that of the incremental PID method. Finally, the calibration experiments for the ADRC control method are implemented using the master–slave robotic system. These experiments demonstrate that the maximum tracking error is 0.87 mm using the ADRC method, effectively guaranteeing surgical safety.

Design and Performance Evaluation of a Novel Vascular Robotic System for Complex Percutaneous Coronary Interventions

The robotic-assisted percutaneous coronary intervention is an emerging technology with great potential to solve the shortcomings of existing treatments. However, the current robotic systems can not manipulate two guidewires or ballons/stents simultaneously for coronary bifurcation lesions. This paper presents VasCure, a novel bio-inspired vascular robotic system, to deliver two guidewires and stents into the main branch and side branch of bifurcation lesions in sequence. The system is designed in master-slave architecture to reduce occupational hazards of radiation exposure and orthopedic injury to interventional surgeons. The slave delivery device has one active roller and two passive rollers to manipulate two interventional devices. The performance of the VasCure was verified by in vitro and in vivo animal experiments. In vitro results showed the robotic system has good accuracy to deliver guidewires and the maximum error is 0.38mm. In an animal experiment, the interventional surgeon delivered two guidewires and balloons to the left circumflex branch and the left anterior descending branch of the pig, which confirmed the feasibility of the vascular robotic system.

An MR-Safe Endovascular Robotic Platform: Design, Control, and Ex-Vivo Evaluation

OBJECTIVE

Cardiovascular diseases are the most common cause of global death. Endovascular interventions, in combination with advanced imaging technologies, are promising approaches for minimally invasive diagnosis and therapy. More recently, teleoperated robotic platforms target improved manipulation accuracy, stabilisation of instruments in the vasculature, and reduction of patient recovery times. However, benefits of recent platforms are undermined by a lack of haptics and residual patient exposure to ionising radiation. The purpose of this research was to design, implement, and evaluate a novel endovascular robotic platform, which accommodates emerging non-ionising magnetic resonance imaging (MRI).

METHODS

We proposed a pneumatically actuated MR-safe teleoperation platform to manipulate endovascular instrumentation remotely and to provide operators with haptic feedback for endovascular tasks. The platform task performance was evaluated in an ex vivo cannulation study with clinical experts ( N = 7) under fluoroscopic guidance and haptic assistance on abdominal and thoracic phantoms.

RESULTS

The study demonstrated that the robotic dexterity involving pneumatic actuation concepts enabled successful remote cannulation of different vascular anatomies with success rates of 90%-100%. Compared to manual cannulation, slightly lower interaction forces between instrumentation and phantoms were measured for specific tasks. The maximum robotic interaction forces did not exceed 3N.

CONCLUSION

This research demonstrates a promising versatile robotic technology for remote manipulation of endovascular instrumentation in MR environments.

SIGNIFICANCE

The results pave the way for clinical translation with device deployment to endovascular interventions using non-ionising real-time 3D MR guidance.

The squeeze strengthening effect on the rheological and microstructured behaviors of magnetorheological fluids: a molecular dynamics study

Systematic molecular dynamics simulations are conducted on magnetorheological (MR) fluids under steady state, squeeze flows and shear flows. The present study concerns the squeeze-assisted MR fluid strengthening and correlates the suspensions' macroscopic rheological properties to their microstructure evolution in terms of the aggregation kinetics. Simulation results demonstrate that the squeeze strengthening effect on the rheological properties of MR fluids is enhanced with the increasing magnetic field and becomes more prominent for dilute suspensions, but weakened with the increasing squeeze rate after the critical squeeze rate is surpassed. By microscopic inspection, it is found that the rheological properties of MR fluids under squeeze flows are consistent with the microstructured behaviors of MR suspensions in terms of the particle distribution, cluster kinetics, particle connectivity and magnetic energy. This study provides a microstructural insight into the squeeze-assisted MR fluid strengthening, which helps to attain an elegant design of MR devices with high shear performance requirements.

Investigation of a Haptic Actuator Made with Magneto-Rheological Fluids for Haptic Shoes Applications

This paper presents a magneto-rheological (MR) actuator that can be easily inserted into haptic shoes and can haptically simulate the material properties of the ground. To increase the resistive force of the proposed actuator, we designed a movable piston having multiple operation modes of MR fluids. Further, the design of a solenoid coil was optimized to maximize the resistive force in a limited-sized MR actuator. Simulations were conducted to predict the actuation performance and to show that the magnetic flux flows well by forming a closed loop in the proposed actuator. The quantitative evaluation of the proposed actuator was investigated by measuring the resistive force as a function of the input current and its pressed depth. From the result, we found that the proposed actuator can create over 600 N by adjusting the input current.

Machine learning-based operation skills assessment with vascular difficulty index for vascular intervention surgery

An accurate assessment of surgical operation skills is essential for improving the vascular intervention surgical outcome and the performance of endovascular surgery robots. In existing studies, subjective and objective assessments of surgical operation skills use a variety of indicators, such as the operation speed and operation smoothness. However, the vascular conditions of particular patients have not been considered in the assessment, leading to deviations in the evaluation. Therefore, in this paper, an operation skills assessment method including the vascular difficulty level index for catheter insertion at the aortic arch in endovascular surgery is proposed. First, the model describing the difficulty of the vascular anatomical structure is established with characteristics of different aortic arch branches based on machine learning. Afterwards, the vascular difficulty level is set as an objective index combined with operating characteristics extracted from the operations performed by surgeons to evaluate the surgical operation skills at the aortic arch using machine learning. The accuracy of the assessment improves from 86.67 to 96.67% after inclusion of the vascular difficulty as an evaluation indicator to more objectively and accurately evaluate skills. The method described in this paper can be adopted to train novice surgeons in endovascular surgery, and for studies of vascular interventional surgery robots. Graphical abstract Operation skill assessment with vascular difficulty for vascular interventional surgery.