Haptic feedback in robotic endovascular neurosurgical intervention: A necessity or a commodity?

Traditionally, both visual and haptic feedback have been regarded as elementary aspects of endovascular neurosurgical intervention. The literature acknowledges that the lack of haptic feedback and the reliance on visual feedback alone in robotic endovascular neurosurgical intervention (RENI) is a limitation. However, several operators who are at the forefront of applying this technology appear to have become quickly accustomed to visual feedback alone. Some have explained their initial scepticism, but upon using the technology they eventually saw the lack of haptic feedback as less of an obstacle and started to regard visual feedback alone as a feasible and safe means to perform procedures. Therefore, this begs the question as to whether haptic feedback is in effect a necessity or a commodity. In this commentary, several considerations are made, presenting arguments supporting the idea that haptic feedback may not be an absolute necessity, and their potential counterarguments. Such reflection and discussion on the topic of haptic feedback in RENI is timely and presently warranted to guide its research and development.

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.

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.

Robotics in neurointerventional surgery: a systematic review of the literature

BACKGROUND

Robotically performed neurointerventional surgery has the potential to reduce occupational hazards to staff, perform intervention with greater precision, and could be a viable solution for teleoperated neurointerventional procedures.

OBJECTIVE

To determine the indication, robotic systems used, efficacy, safety, and the degree of manual assistance required for robotically performed neurointervention.

METHODS

We conducted a systematic review of the literature up to, and including, articles published on April 12, 2021. Medline, PubMed, Embase, and Cochrane register databases were searched using medical subject heading terms to identify reports of robotically performed neurointervention, including diagnostic cerebral angiography and carotid artery intervention.

RESULTS

A total of 8 articles treating 81 patients were included. Only one case report used a robotic system for intracranial intervention, the remaining indications being cerebral angiography and carotid artery intervention. Only one study performed a comparison of robotic and manual procedures. Across all studies, the technical success rate was 96% and the clinical success rate was 100%. All cases required a degree of manual assistance. No studies had clearly defined patient selection criteria, reference standards, or index tests, preventing meaningful statistical analysis.

CONCLUSIONS

Given the clinical success, it is plausible that robotically performed neurointerventional procedures will eventually benefit patients and reduce occupational hazards for staff; however, there is no high-level efficacy and safety evidence to support this assertion. Limitations of current robotic systems and the challenges that must be overcome to realize the potential for remote teleoperated neurointervention require further investigation.

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 Intravascular Catheter Bending Recognition Method for Interventional Surgical Robots

Robot-assisted interventional surgery can greatly reduce the radiation received by surgeons during the operation, but the lack of force detection and force feedback is still a risk in the operation which may harm the patient. In those robotic surgeries, the traditional force detection methods may have measurement losses and errors caused by mechanical transmission and cannot identify the direction of the force. In this paper, an interventional surgery robot system with a force detection device is designed and a new force detection method based on strain gauges is proposed to detect the force and infer the bending direction of the catheter in the vessel by using BP neural network. In addition, genetic algorithm is used to optimize the BP neural network, and the error between the calculated results and the actual results is reduced by 37%, which improves the accuracy of catheter bending recognition. Combining this new method with traditional force sensors not only reduces the error caused by the traditional mechanical transmission, but also can detect the bending direction of the catheter in the blood vessel, which greatly improves the safety of the operation.

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.

A Vascular Intervention Assist Device Using Bi-Motional Roller Cartridge Structure and Clinical Evaluation

Conventional vascular intervention procedures present issues including X-ray exposure during operation, and an experience-dependent success rate and clinical outcome. This paper presents a novel robotic system using modularized bi-motional roller cartridge assemblies for robotic vascular interventions, specifically percutaneous coronary interventions (PCIs). The patient-side robot manipulates instruments such as the guiding catheter, guidewire, balloon/stent catheter, and diagnostic sensor catheter via commands from the user interface device, which is controlled by the physician. The proposed roller cartridge assembly can accommodate instruments of various sizes with an active clamping mechanism, and implements simultaneous translation and rotation motions. It also implements force feedback in the physician-side system, to effectively monitor the patient-side system’s status. The positioning accuracy and precision in using the robotic system showed satisfactory performance in a phantom-based test. It was also confirmed, through animal experiments and a pilot clinical trial, that the system demonstrates feasibility for clinical use.

Force feedback controls of multi-gripper robotic endovascular intervention: design, prototype, and experiments

PURPOSE

Robotic endovascular intervention system (REIS) has the advantages of telemanipulation without radiation damage, precise location, and isolation of hand quiver. However, current REIS lacks a force feedback, which leads to high clinical risks. For the high operational safety of remote operations, this research proposes a force feedback control method for a novel manipulator with multi-grippers and develops a prototype to verify its expected telepresence.

METHODS

A high-resolution force sensor is used to acquire and transmit the intervention resistance force to the control handle. When the handle is translated or rotated, a loading mechanism composed of a servomotor, a screw pair, a spring, and friction roller generates the resistance force transmitted to the doctor's hand through the handle. A force/displacement hybrid control and PID control algorithm are used for the smaller feedback force error and lower delay.

RESULTS

This manipulator and its control handle are tested in the simulated catheter and vascular cases. The experiments show that force feedback precision can reach 0.05 N and the delay is not more than 50 ms, and the bandwidth is 9 Hz@-3 dB.

CONCLUSION

The proposed force feedback method can recreate resistance force from the intervention devices. The control model is valid with higher precision and wide bands, which has laid foundations to the application of REIS in clinic.

Haptic Telerobotic Cardiovascular Intervention: A Review of Approaches, Methods, and Future Perspectives

Cardiac diseases are recognized as the leading cause of mortality, hospitalization, and medical prescription globally. The gold standard for the treatment of coronary artery stenosis is the percutaneous cardiac intervention that is performed under live X-ray imaging. Substantial clinical evidence shows that the surgeon and staff are prone to serious health problems due to X-ray exposure and occupational hazards. Telerobotic vascular intervention systems with a master-slave architecture reduced the X-ray exposure and enhanced the clinical outcomes; however, the loss of haptic feedback during surgery has been the main limitation of such systems. This paper is a review of the state of the art for haptic telerobotic cardiovascular interventions. A survey on the literature published between 2000 and 2019 was performed. Results of the survey were screened based on their relevance to this paper. Also, the leading research disciplines were identified based on the results of the survey. Furthermore, different approaches for sensor-based and model-based haptic telerobotic cardiovascular intervention, haptic rendering and actuation, and the pertinent methods were critically reviewed and compared. In the end, the current limitations of the state of the art, unexplored research areas as well as the future perspective of the research on this technology were laid out.

Analysis of Interventionalists' Natural Behaviors for Recognizing Motion Patterns of Endovascular Tools During Percutaneous Coronary Interventions

Many robotic platforms can indeed reduce radiation exposure to clinicians during percutaneous coronary intervention (PCI), however, interventionalists' natural manipulations are rarely involved in robot-assisted PCI. This requires more attention to analyze interventionalists' natural behaviors during conventional PCI. In this study, four types of natural behavior (i.e., muscle activity, hand motion, proximal force, and finger motion) were synchronously acquired from ten subjects while performing six typical types of guidewire manipulation. These behaviors are evaluated by a hidden Markov model (HMM) based analysis framework for relevant behavior selection. Relevant behaviors are further used as the input of two HMM-based classification frameworks to recognize guidewire motion patterns. Experimental results show that under the basic classification framework (BCF), 91.01% and 93.32% recognition accuracies can be achieved by using all behaviors and relevant behaviors, respectively. Furthermore, the hierarchical classification framework can significantly enhance the recognition ability of relevant behaviors with an accuracy of 96.39%. These promising results demonstrate great potential of proposed methods for promoting the future design of human-robot interfaces in robot-assisted PCI.

A marker-based contactless catheter-sensing method to detect surgeons' operations for catheterization training systems

It is challenging to position a catheter or a guidewire within a patient's complicated and delicate vascular structure due to the lack of intuitive visual feedback by only manipulating the proximal part of the surgical instruments. Training is therefore critical before an actual surgery because any mistake due to the surgeon's inexperience can be fatal for the patient. The catheter manipulation skills of experienced surgeons can be useful as input for training novice surgeons. However, few research groups focused on designs with consideration of the contactless catheter motion measurement, which allows obtaining expert surgeons' catheter manipulation trajectories whilst still allowing them to employ an actual catheter and apply conventional pull, push and twist of the catheter as used in bedside intravascular interventional surgeries. In this paper, a novel contactless catheter-sensing method is proposed to measure the catheter motions by detecting and tracking a passive marker with four feature-point groups. The passive marker is designed to allow simultaneously sensing the translational and rotational motions of the input catheter. Finally, the effectiveness of the proposed contactless catheter-sensing method is validated by conducting a series of comparison experiments. The accuracy and error analysis are quantified based on the absolute error, relative error, mean absolute error, and the success rate of the detection.

Design and Development of Surgeon Augmented Endovascular Robotic System

OBJECTIVE

Inadequate visual and force feedback while navigating surgical tools elevate the risk of endovascular procedures. It also poses occupational hazard due to repeated exposure to X-rays. A teleoperated robotic system that augments surgeon's actions is a solution.

METHOD

We have designed and developed an endovascular robotic system that augments surgeon's actions using conventional surgical tools, as well as generates feedback in order to ensure safety during the procedure. The reaction force from vasculature is estimated from motor current that drives the surgical tool. Calibration required for force estimation is based on bilevel optimization. Input shaping is used in conjunction with a cascaded controller to avoid large responses due to faster inputs and to track tool position. The design, realization, and testing of our system are presented.

RESULTS

The responses of the system in comparison with the dynamics model is similar vis-à-vis the same input commands. Any error in the position tracking is reduced by the cascaded controller. Phase-portrait analysis of the system showed that the system is stable. The reaction force estimation is validated against load cell measurements. The safety mechanism in the events of excessive reaction forces while interacting with vasculature is demonstrated.

CONCLUSION AND SIGNIFICANCE

Our system is a step toward intelligent robots that can assist surgeons during endovascular procedures by monitoring and alerting the surgeons regarding detrimental parameters. It arrests any unintended excursions of the surgical tools or surgeon's actions. This will also eliminate the need for surgeons to be in radiation environment.

Performance evaluation of a robot-assisted catheter operating system with haptic feedback

In this paper, a novel robot-assisted catheter operating system (RCOS) has been proposed as a method to reduce physical stress and X-ray exposure time to physicians during endovascular procedures. The unique design of this system allows the physician to apply conventional bedside catheterization skills (advance, retreat and rotate) to an input catheter, which is placed at the master side to control another patient catheter placed at the slave side. For this purpose, a magnetorheological (MR) fluids-based master haptic interface has been developed to measure the axial and radial motions of an input catheter, as well as to provide the haptic feedback to the physician during the operation. In order to achieve a quick response of the haptic force in the master haptic interface, a hall sensor-based closed-loop control strategy is employed. In slave side, a catheter manipulator is presented to deliver the patient catheter, according to position commands received from the master haptic interface. The contact forces between the patient catheter and blood vessel system can be measured by designed force sensor unit of catheter manipulator. Four levels of haptic force are provided to make the operator aware of the resistance encountered by the patient catheter during the insertion procedure. The catheter manipulator was evaluated for precision positioning. The time lag from the sensed motion to replicated motion is tested. To verify the efficacy of the proposed haptic feedback method, the evaluation experiments in vitro are carried out. The results demonstrate that the proposed system has the ability to enable decreasing the contact forces between the catheter and vasculature.

Operation evaluation in-human of a novel remote-controlled vascular interventional robot

Remote-controlled vascular interventional robots (RVIRs) are being developed to increase the accuracy of surgical operations and reduce the number of occupational risks sustained by intervening physicians, such as radiation exposure and chronic neck/back pain. However, complex control of the RVIRs improves the doctor's operation difficulty and reduces the operation efficiency. Furthermore, incomplete sterilization of the RVIRs will increase the risk of infection, or even cause medical accidents. In this study, we introduced a novel method that provides higher operation efficiency than a previous prototype and allows for complete robot sterilization. A prototype was fabricated and validated through laboratory setting experiments and an in-human experiment. The results illustrated that the proposed RVIR has better performance compared with the previous prototype, and preliminarily demonstrated that the proposed RVIR has good safety and reliability and can be used in clinical surgeries.

Operating force information on-line acquisition of a novel slave manipulator for vascular interventional surgery

Vascular interventional surgery has its advantages compared to traditional operation. Master-slave robotic technology can further improve the operation accuracy, efficiency and safety of this complicated and high risk surgery. However, on-line acquisition of operating force information of catheter and guidewire remains to be a significant obstacle on the path to enhancing robotic surgery safety. Thus, a novel slave manipulator is proposed in this paper to realize on-line sensing of guidewire torsional operating torque and axial operation force during robotic assisted operations. A strain sensor is specially designed to detect the small scale torsional operation torque with low rotational frequency. Additionally, the axial operating force is detected via a load cell, which is incorporated into a sliding mechanism to eliminate the influence of friction. For validation, calibration and performance evaluation experiments are conducted. The results indicate that the proposed operation torque and force detection device is effective. Thus, it can provide the foundation for enabling accurate haptic feedback to the surgeon to improve surgical safety.

Design and performance evaluation of collision protection-based safety operation for a haptic robot-assisted catheter operating system

The robot-assisted catheter system can increase operating distance thus preventing the exposure radiation of the surgeon to X-ray for endovascular catheterization. However, few designs have considered the collision protection between the catheter tip and the vessel wall. This paper presents a novel catheter operating system based on tissue protection to prevent vessel puncture caused by collision. The integrated haptic interface not only allows the operator to feel the real force feedback, but also combines with the newly proposed collision protection mechanism (CPM) to mitigate the collision trauma. The CPM can release the catheter quickly when the measured force exceeds a certain threshold, so as to avoid the vessel puncture. A significant advantage is that the proposed mechanism can adjust the protection threshold in real time by the current according to the actual characteristics of the blood vessel. To verify the effectiveness of the tissue protection by the system, the evaluation experiments in vitro were carried out. The results show that the further collision damage can be effectively prevented by the CPM, which implies the realization of relative safe catheterization. This research provides some insights into the functional improvements of safe and reliable robot-assisted catheter systems.

A cooperation of catheters and guidewires-based novel remote-controlled vascular interventional robot

Remote-controlled vascular interventional robots (RVIRs) are being developed to increase the overall accuracy of surgical operations and reduce the occupational risks of intervening physicians, such as radiation exposure and chronic neck/back pain. Several RVIRs have been used to operate catheters or guidewires accurately. However, a lack of cooperation between the catheters and guidewires results in the surgeon being unable to complete complex surgery by propelling the catheter/guidewire to the target position. Furthermore, it is a significant challenge to operate the catheter/guidewire accurately and detect their proximal force without damaging their surfaces. In this study, we introduce a novel method that allows catheters and guidewires to be operated simultaneously in complex surgery. Our method accurately captures force measurements and enables precisely controlled catheter and guidewire operation. A prototype is validated through various experiments. The results demonstrate the feasibility of the proposed RVIR to operate a catheter and guidewire accurately, detect the resistance forces, and complete complex surgical operations in a cooperative manner.

CathROB: A Highly Compact and Versatile Remote Catheter Navigation System

Several remote catheter navigation systems have been developed and are now commercially available. However, these systems typically require specialized catheters or equipment, as well as time-consuming operations for the system set-up. In this paper, we present CathROB, a highly compact and versatile robotic system for remote navigation of standard tip-steerable electrophysiology (EP) catheters. Key features of CathROB include an extremely compact design that minimizes encumbrance and time for system set-up in a standard cath lab, a force-sensing mechanism, an intuitive command interface, and functions for automatic catheter navigation and repositioning. We report in vitro and in vivo animal evaluation of CathROB. In vitro results showed good accuracy in remote catheter navigation and automatic repositioning (1.5 ± 0.6 mm for the left-side targets, 1.7 ± 0.4 mm for the right-side targets). Adequate tissue contact was achieved with remote navigation in vivo. There were no adverse events, including absence of cardiac perforation or cardiac damage, indicative of the safety profile of CathROB. Although further preclinical and clinical studies are required, the presented CathROB system seems to be a promising solution for an affordable and easy-to-use remote catheter navigation.

An assembly-type master-slave catheter and guidewire driving system for vascular intervention

Current vascular intervention inevitably exposes a large amount of X-ray to both an operator and a patient during the procedure. The purpose of this study is to propose a new catheter driving system which assists the operator in aspects of less X-ray exposure and convenient user interface. For this, an assembly-type 4-degree-of-freedom master-slave system was designed and tested to verify the efficiency. First, current vascular intervention procedures are analyzed to develop a new robotic procedure that enables us to use conventional vascular intervention devices such as catheter and guidewire which are commercially available in the market. Some parts of the slave robot which contact the devices were designed to be easily assembled and dissembled from the main body of the slave robot for sterilization. A master robot is compactly designed to conduct insertion and rotational motion and is able to switch from the guidewire driving mode to the catheter driving mode or vice versa. A phantom resembling the human arteries was developed, and the master-slave robotic system is tested using the phantom. The contact force of the guidewire tip according to the shape of the arteries is measured and reflected to the user through the master robot during the phantom experiment. This system can drastically reduce radiation exposure by replacing human effort by a robotic system for high radiation exposure procedures. Also, benefits of the proposed robot system are low cost by employing currently available devices and easy human interface.

Design and control of a novel gastroscope intervention mechanism with circumferentially pneumatic-driven clamping function

BACKGROUND

Robot-assisted manipulation is promising for solving problems such as understaffing and the risk of infection in gastro-intestinal endoscopy. However, the commonly used friction rollers in few existing systems have a potential risk of deforming flexible endoscopes for non-uniform clamping.

METHODS

This paper presents a robotic system for a standard flexible endoscope and focuses on a novel gastroscope intervention mechanism (GIM), which provides circumferentially uniform clamping with an airbag. The GIM works with a relay-on mechanism in a way similar to manual operation. The shear stiffness of airbag and the critical slipping force (CSF) were analysed to determine the parameters of the airbag. A fuzzy PID controller was employed to realize a fast response and high accuracy of pneumatic actuation. Experiments were performed to evaluate the accuracy, stiffness and CSF. In vitro and in vivo animal experiments were also carried out.

RESULTS

The GIM realized an accuracy of 0.025 ± 0.2 mm and -0.03 ± 0.25° for push-pull and rotation without delivery resistance. Under < 10 N delivery resistance, the error caused by the airbag stiffness was < 0.24 mm. A quadratic polynomial could be used to describe the relationship between the CSF and pneumatic pressure.

CONCLUSIONS

The novel GIM could effectively deliver gastroscopes. The pneumatic-driven clamping method proposed could protect the gastroscope by circumferentially uniform clamping force and the CSF could be properly controlled to guarantee operating safety. Copyright © 2016 John Wiley & Sons, Ltd.

A novel gastroscope intervention mechanism with circumferentially pneumatic-driven clamping function

Robotic assisted gastroscope delivery could solve various problems like understaffing, radiation and infection risk. The friction rollers commonly used in the few existed systems for traditional flexible endoscope, however, has potential risk of destroying scopes for non-uniform clamping. This research develops a novel gastroscope intervention mechanism (GIM) with a specially designed airbag. It evenly clamps the gastroscope with circumferential uniform pneumatic pressure. The GIM realizes axial and radial motion by means of the relay delivery mode similar to clinician's operation. The critical slipping force at different air pressure was analyzed to provide guidelines for safe intervention. Experiments were performed to evaluate the delivery accuracy and velocity and measure the critical slipping force. The results showed the axial and radial accuracy for delivery are 0.025±0.2mm and -0.03±0.25deg, respectively. The average velocity of 6.00mm·s(-1) and 75 deg·s(-1) were achieved to push/pull and twist the gastroscope. The relationship between the critical slipping force and air pressure could be fitted with a quadratic polynomial.

Preliminary study for motion scaling based control in minimally invasive vascular interventional robot

Robot-assisted vascular interventions present promising trend for reducing the X-ray radiation to the surgeon during the operation. However, the control methods in the current vascular interventional robots only repeat the manipulation of the surgeon. While under certain circumstances, it is necessary to scale the manipulation of the surgeon to obtain a higher precision or a shorter manipulation time. A novel control method based on motion scaling for vascular interventional robot is proposed in this paper. The main idea of the method is to change the motion speed ratios between the master and the slave side. The motion scaling based control method is implemented in the vascular interventional robot we've developed before, so the operator can deliver the interventional devices under different motion scaling factors. Experiment studies verify the effectiveness of the motion scaling based control.

Design, development and evaluation of a compact telerobotic catheter navigation system

BACKGROUND

Remote catheter navigation systems protect interventionalists from scattered ionizing radiation. However, these systems typically require specialized catheters and extensive operator training.

METHODS

A new compact and sterilizable telerobotic system is described, which allows remote navigation of conventional tip-steerable catheters, with three degrees of freedom, using an interface that takes advantage of the interventionalist's existing dexterity skills. The performance of the system is evaluated ex vivo and in vivo for remote catheter navigation and ablation delivery.

RESULTS

The system has absolute errors of 0.1 ± 0.1 mm and 7 ± 6° over 100 mm of axial motion and 360° of catheter rotation, respectively. In vivo experiments proved the safety of the proposed telerobotic system and demonstrated the feasibility of remote navigation and delivery of ablation.

CONCLUSION

The proposed telerobotic system allows the interventionalist to use conventional steerable catheters; while maintaining a safe distance from the radiation source, he/she can remotely navigate the catheter and deliver ablation lesions. Copyright © 2015 John Wiley & Sons, Ltd.

Design and performance evaluation of a master controller for endovascular catheterization

PURPOSE

It is difficult to manipulate a flexible catheter to target a position within a patient's complicated and delicate vessels. However, few researchers focused on the controller designs with much consideration of the natural catheter manipulation skills obtained from manual catheterization. Also, the existing catheter motion measurement methods probably lead to the difficulties in designing the force feedback device. Additionally, the commercially available systems are too expensive which makes them cost prohibitive to most hospitals. This paper presents a simple and cost-effective master controller for endovascular catheterization that can allow the interventionalists to apply the conventional pull, push and twist of the catheter used in current practice.

METHODS

A catheter-sensing unit (used to measure the motion of the catheter) and a force feedback unit (used to provide a sense of resistance force) are both presented. A camera was used to allow a contactless measurement avoiding additional friction, and the force feedback in the axial direction was provided by the magnetic force generated between the permanent magnets and the powered coil.

RESULTS

Performance evaluation of the controller was evaluated by first conducting comparison experiments to quantify the accuracy of the catheter-sensing unit, and then conducting several experiments to evaluate the force feedback unit. From the experimental results, the minimum and the maximum errors of translational displacement were 0.003 mm (0.01 %) and 0.425 mm (1.06 %), respectively. The average error was 0.113 mm (0.28 %). In terms of rotational angles, the minimum and the maximum errors were 0.39°(0.33 %) and 7.2°(6 %), respectively. The average error was 3.61°(3.01 %). The force resolution was approximately 25 mN and a maximum current of 3A generated an approximately 1.5 N force.

CONCLUSION

Based on analysis of requirements and state-of-the-art computer-assisted and robot-assisted training systems for endovascular catheterization, a new master controller with force feedback interface was proposed to maintain the natural endovascular catheterization skills of the interventionalists.

Current and emerging robot-assisted endovascular catheterization technologies: a review

Endovascular techniques have been embraced as a minimally-invasive treatment approach within different disciplines of interventional radiology and cardiology. The current practice of endovascular procedures, however, is limited by a number of factors including exposure to high doses of X-ray radiation, limited 3D imaging, and lack of contact force sensing from the endovascular tools and the vascular anatomy. More recently, advances in steerable catheters and development of master/slave robots have aimed to improve these practices by removing the operator from the radiation source and increasing the precision and stability of catheter motion with added degrees-of-freedom. Despite their increased application and a growing research interest in this area, many such systems have been designed without considering the natural manipulation skills and ergonomic preferences of the operators. Existing studies on tool interactions and natural manipulation skills of the operators are limited. In this manuscript, new technical developments in different aspects of robotic endovascular intervention including catheter instrumentation, intra-operative imaging and navigation techniques, as well as master/slave based robotic catheterization platforms are reviewed. We further address emerging trends and new research opportunities towards more widespread clinical acceptance of robotically assisted endovascular technologies.

Accurate guidance of a catheter by ultrasound imaging and identification of a catheter tip by pulsed-wave Doppler

BACKGROUND

With the advent of numerous minimally invasive medical procedures, accurate catheter guidance has become imperative. We introduce and test an approach for catheter guidance by ultrasound imaging and pulsed-wave (PW) Doppler.

METHODS

A steerable catheter is fitted with a small piezoelectric crystal at its tip that actively transmits signals driven by a function generator. We call this an active-tip (AT) catheter. In a water tank, we immersed a "target" crystal and a rectangular matrix of four "reference" crystals. Two-dimensional (2D) ultrasound imaging was used for initial guidance and visualization of the catheter shaft, and then PW Doppler mode was used to identify the AT catheter tip and guide it to the simulated target that was also visible in the 2D ultrasound image. Ten guiding trials were performed from random initial positions of the AT catheter, each starting at approximately 8 cm from the target.

RESULTS

After the ten navigational trials, the average final distance of the catheter tip from the target was 2.4 ± 1.2 mm, and the range of distances from the trials was from a minimum of 1.0 mm to a maximum of 4.5 mm.

CONCLUSIONS

Although early in the development process, these quantitative in vitro results show promise for catheter guidance with ultrasound imaging and tip identification by PW Doppler.

Right-side RF ablation using remote catheter navigation: experimental results in vivo

INTRODUCTION

The close proximity between the interventionalist and patient during catheter-based interventions for cardiac arrhythmia exposes the interventionalist to harmful radiation. A prototype remote catheter navigation system (RCNS) has been developed to reduce occupational dose. The safety, feasibility of this RCNS and a comparison of remote and conventional navigation techniques is investigated in vivo.

METHODS

Seven anatomical locations in the right side of the heart in porcine models were chosen as navigation targets. Using fluoroscopy and electrogram analysis, an experienced electrophysiology interventionalist manipulated a radiofrequency (RF) ablation catheter to each target using the RCNS and conventional navigation. Success rate, navigation time, exposure, exposure time and procedure time was recorded for all anatomical targets. Time to integrate the RCNS with the procedure suite was also measured.

RESULTS

All targets were successfully reached with the RCNS and conventional navigation. No erratic catheter motion was observed with the RCNS whereas 1 operation failure occurred. The anatomical targets were found to have the largest effect on navigation time (P < 0.05), exposure (P < 0.05), and exposure time (P < 0.01), although the navigation method had little to no effect on the metrics. These results suggest that remote navigation procedures can be performed with navigation times comparable to conventional bedside navigation.

CONCLUSION

Remote navigation with the RCNS may present a safe method of reducing occupational dose, while providing comparable navigation time with conventional bedside navigation.