Novel, magnetically guided catheter for endocardial mapping and radiofrequency catheter ablation

A Human-Scale Clinically Ready Electromagnetic Navigation System for Magnetically Responsive Biomaterials and Medical Devices

Magnetic navigation systems are used to precisely manipulate magnetically responsive materials enabling the realization of new minimally invasive procedures using magnetic medical devices. Their widespread applicability has been constrained by high infrastructure demands and costs. The study reports on a portable electromagnetic navigation system, the Navion, which is capable of generating a large magnetic field over a large workspace. The system is easy to install in hospital operating rooms and transportable through health care facilities, aiding in the widespread adoption of magnetically responsive medical devices. First, the design and implementation approach for the system are introduced and its performance is characterized. Next, in vitro navigation of different microrobot structures is demonstrated using magnetic field gradients and rotating magnetic fields. Spherical permanent magnets, electroplated cylindrical microrobots, microparticle swarms, and magnetic composite bacteria-inspired helical structures are investigated. The navigation of magnetic catheters is also demonstrated in two challenging endovascular tasks: 1) an angiography procedure and 2) deep navigation within the circle of Willis. Catheter navigation is demonstrated in a porcine model in vivo to perform an angiography under magnetic guidance.

Robotic magnetic navigation-guided catheter ablation establishes highly effective pulmonary vein isolation in patients with paroxysmal atrial fibrillation when compared to conventional ablation techniques

INTRODUCTION

Pulmonary vein isolation (PVI) is a pivotal part of ablative therapy for atrial fibrillation (AF). Currently, there are multiple techniques available to realize PVI, including: manual-guided cryoballoon (MAN-CB), manual-guided radiofrequency (MAN-RF), and robotic magnetic navigation-guided radiofrequency ablation (RMN-RF). There is a lack of large prospective trials comparing contemporary RMN-RF with the more conventional ablation techniques. This study prospectively compared three catheter ablation techniques as treatment of paroxysmal AF.

METHODS

This multicenter, prospective study included patients with paroxysmal AF who underwent their first ablation procedure. Procedural parameters (including procedural efficiency), complication rates, and freedom of AF during 12-month follow-up, were compared between three study groups which were defined by the utilized ablation technique.

RESULTS

A total of 221 patients were included in this study. Total procedure time was significantly shorter in MAN-CB (78 ± 21 min) compared to MAN-RF (115 ± 41 min; p < .001) and compared to RMN-RF (129 ± 32 min; p < .001), whereas it was comparable between the two radiofrequency (RF) groups (p = .062). A 3% complication rate was observed, which was comparable between all groups. At 12-month follow-up, AF recurrence was observed in 40 patients (19%) and was significantly lower in the robotic group (MAN-CB 19 [24%], MAN-RF 16 [23%], RMN-RF 5 [8%] AF recurrences, p = .045) (multivariate hazard ratio of RMN-RF on AF recurrence 0.32, 95% confidence interval: 0.12-0.87, p = .026).

CONCLUSION

RMN-guided PVI results in high freedom of AF in patients with paroxysmal AF, when compared to cryoablation and manual RF ablation. Cryoablation remains the most time-efficient ablation technique, whereas RMN nowadays has comparable efficiency with manual RF ablation.

The performance of dipole charge density mapping integrated with robotic magnetic navigation in the treatment of atrial tachycardias

BACKGROUND

Catheter ablation (CA) has become a well-established first-line therapy for a broad spectrum of arrhythmias, including atrial tachycardias (ATs). In this study we aimed to assess the performance of the integrated novel high-resolution new generation noncontact mapping system (AcQMap) with robotic magnetic navigation (RMN) system in CA procedures for patients with ATs including comparing patient subgroups based on the utilized mapping modality, arrhythmia mechanism, localization and type of procedure.

METHODS

All patients undergoing CA for AT using the AcQMap-RMN system were included. Procedural safety and efficacy were characterized by intra- and post-procedural complications. Acute procedural success and the long-term outcome were assessed in the overall group and in the subgroups.

RESULTS

A total number of 70 patients were referred for CA with atrial arrhythmias including 67 AT/AFL (mean age 57.1 ± 14.4 years), and 3 additional patients with inappropriate sinus tachycardia. Thirty-eight patients had de novo AT, 24 had post-PVI AT including 2 patients with perinodal AT, and 5 had post-MAZE AT. Two patients (2.9%) suffered post-procedural complications including 1 patient with groin hematoma and 1 patient with a transient ischemic attack. Acute success was achieved in 63/67 (94.0%) procedures. Thirteen patients (19.4%) had documented recurrence at the end of the 12-months follow-up period. The performance of AcQMap was equally good in focal vs. reentry mechanisms (p = 0.61, acute success), in the left and right atrium (p = 0.21).

CONCLUSIONS

AcQMap-RMN integration might improve success rates in CA of ATs with low number of complications.

Dipole charge density mapping integrated in remote magnetic navigation: First-in-human feasibility study

Aims

Robotic magnetic navigation (RMN) provides increased catheter precision and stability. Formerly, only the CARTO 3 mapping system was integrated with the RMN system (CARTO-RMN). Recently, a novel high-resolution non-contact mapping system (AcQMap) has been integrated with the RMN system (AcQMap-RMN) for the treatment of atrial fibrillation (AF) and atrial tachycardias (AT). We aim to compare the safety, efficiency, and efficacy of AcQMap-RMN with CARTO-RMN guided catheter ablation (CA) procedures.

Material and methods

In this prospective registry, procedural safety efficiency and outcome data from total of 238 consecutive patients (147 AcQMap-RMN and 91 CARTO-RMN patients) were compared.

Results

AcQMap-RMN is non-inferior in the primary endpoint of safety as compared to CARTO-RMN across the whole group (overall procedural complications in 5 (3.4%) vs. 3 (3.3%) patients, p = 1.0). Overall procedure durations were longer and associated with more fluoroscopy use with AcQMap-RMN (172.5 vs. 129.6 min, p < 0.01; 181.0 vs. 131.0 mGy, p = 0.02, respectively). Procedure duration and fluoroscopy use decreased significantly between the first 30 and the last 30 AcQMap-RMN procedures. The AcQMap-RMN system had fewer recurrences after persistent AF ablations and was non-inferior in paroxysmal AF patients compared to CARTO-RMN at 12 months (36.6% vs. 75.0%, p = 0.04, PAF 6.6% vs. 12.5%, p = 0.58; respectively). CA of AT outcomes were better using the AcQMap-RMN system (1 year recurrence 17.1% vs. 38.7%, p < 0.05).

Conclusion

AcQMap-RMN integration has no negative impact on the excellent safety profile of RMN guided ablations. It improves outcomes of CA procedures for persAF and AT but requires longer procedure times and higher fluoroscopy use during the initial learning phase.

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.

Going Hands-Free: MagnetoSuture™ for Untethered Guided Needle Penetration of Human Tissue Ex Vivo

The application of force in surgical settings is typically accomplished via physical tethers to the surgical tool. While physical tethers are common and critical, some internal surgical procedures may benefit from a tetherless operation of needles, possibly reducing the number of ports in the patient or the amount of tissue damage caused by tools used to manipulate needles. Magnetic field gradients can dynamically apply kinetic forces to magnetizable objects free of such tethers, possibly enabling ultra-minimally invasive robotic surgical procedures. We demonstrate the untethered manipulation of a suture needle in vitro, exemplified by steering through narrow holes, as well as needle penetration through excised rat and human tissues. We present proof of principle manipulations for the fully untethered control of a minimally modified, standard stainless steel surgical suture needle.

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.

Remote magnetic navigation shows superior long-term outcomes in pediatric atrioventricular (nodal) tachycardia ablation compared to manual radiofrequency and cryoablation

Background

Catheter ablation (CA) is the first-choice treatment for tachyarrhythmia in children. Currently available CA techniques differ in mechanism of catheter navigation and energy sources. There are no large studies comparing long-term outcomes between available CA techniques in a pediatric population with atrioventricular reentry tachycardia (AVRT) or atrioventricular nodal reentry tachycardia (AVNRT) mechanisms.

Objective

This study aimed to compare procedural and long-term outcomes of remote magnetic navigation-guided radiofrequency (RF) ablation (RMN), manual-guided RF ablation (MAN) and manual-guided cryoablation (CRYO).

Methods

This single-center, retrospective study included all first consecutive CA procedures for AVRT or AVNRT performed in children without structural heart disease from 2008 to 2019. Three study groups were defined by the ablation technique used: RMN, MAN or CRYO. Primary outcome was long-term recurrence of tachyarrhythmia.

Results

In total, we included 223 patients, aged 14 (IQR 12-16) years; weighting 56 (IQR 47-65) kilograms. In total, 108 procedures were performed using RMN, 76 using MAN and 39 using CRYO. RMN had significantly lower recurrence rates compared to MAN and CRYO at mean follow-up of 5.5 ± 2.9 years (AVRT: 4.3% versus 15.6% versus 54.5%, P < 0.001; AVNRT: 7.7% versus 8.3% versus 35.7%, P = 0.008; for RMN versus MAN versus CRYO respectively). In AVNRT ablation, RMN had significantly lower fluoroscopy doses compared to CRYO [30 (IQR 20-41) versus 45 (IQR 29-65) mGy, P = 0.040).

Conclusion

In pediatric patients without structural heart disease who underwent their first AV(N)RT ablation, RMN has superior long-term outcomes compared to MAN and CRYO, in addition to favorable fluoroscopy doses.

Artificial intelligence in the diagnosis and management of arrhythmias

The field of cardiac electrophysiology (EP) had adopted simple artificial intelligence (AI) methodologies for decades. Recent renewed interest in deep learning techniques has opened new frontiers in electrocardiography analysis including signature identification of diseased states. Artificial intelligence advances coupled with simultaneous rapid growth in computational power, sensor technology, and availability of web-based platforms have seen the rapid growth of AI-aided applications and big data research. Changing lifestyles with an expansion of the concept of internet of things and advancements in telecommunication technology have opened doors to population-based detection of atrial fibrillation in ways, which were previously unimaginable. Artificial intelligence-aided advances in 3D cardiac imaging heralded the concept of virtual hearts and the simulation of cardiac arrhythmias. Robotics, completely non-invasive ablation therapy, and the concept of extended realities show promise to revolutionize the future of EP. In this review, we discuss the impact of AI and recent technological advances in all aspects of arrhythmia care.

Outcomes of manual versus remote magnetic navigation for catheter ablation of ventricular tachycardia: a systematic review and updated meta-analysis

PURPOSE

Ventricular tachycardia (VT) ablation is a complex procedure that requires remarkable catheter manipulation skill, great mapping accuracy and catheter stability, and can expose patients to serious complications. Magnetic navigation system (RMN)-guided ablation and contact force-sensing (CFS) catheters have the potential to overcome these obstacles. We performed a systematic review and updated meta-analysis of all available studies evaluating the outcomes of VT ablation by using RMN-guided compared to manual navigation (MAN)-guided, with and without CFS catheters.

METHODS

MEDLINE/PubMed, Cochrane, and Google Scholar were searched for randomized controlled trials (RCT) or observational studies with multivariate adjustment comparing RMN-guided versus MAN-guided VT ablation.

RESULTS

Thirteen studies enrolling 1348 patients (656 RMN-guided vs. 692 MAN-guided) were included. CFS catheter were used in 14% of MAN-guided patients. In comparison to MAN-guided and CFS-guided, RMN-guided VT ablation was associated with a significant higher acute ablation success (OR 2.32, 1.66-3.23 and OR 2.91, 1.29-6.53, respectively) but similar results in term of long-term VT recurrence (OR 0.75, 0.56-1.01 and OR 0.79, 0.27-2.36, respectively). RMN-guided showed a better safety profile (for all complications, OR 0.52, 0.34-0.81) and allowed a significant x-ray reduction compared to MAN-guided (OR 0.21, 0.14-0.32) and CFS-guided VT ablation (OR 0.23, 0.11-0.52, all 95% CI).

CONCLUSIONS

RMN-guided was superior to MAN-guided and CFS-guided VT ablation in term of acute ablation success, all complications endpoint, and reduction of fluoroscopy exposure, but did not reduce long-term VT recurrence. Large prospective multicenter randomized trials are needed to confirm these findings.

Magnetic Forces Enable Control of Biological Processes In Vivo

Similar to mechanical forces that can induce profound biological effects, magnetic fields can have a broad range of implications to biological systems, from magnetoreception that allows an organism to detect a magnetic field to perceive direction, altitude, or location, to the use of heating induced by magnetic field for altering neuron activity. This review focuses on the application of magnetic forces generated by magnetic iron oxide nanoparticles (MIONs), which can also provide imaging contrast and mechanical/thermal energy in response to an external magnetic field, a special feature that distinguishes MIONs from other nanomaterials. The magnetic properties of MIONs offer unique opportunities for enabling control of biological processes under different magnetic fields. Here, we describe the approaches of utilizing the forces generated by MIONs under an applied magnetic field to control biological processes and functions, including the targeting of drug molecules to a specific tissue, increasing the vessel permeability for improving drug delivery, and activating a particular viral vector for spatial control of genome editing in vivo. The opportunities of using nanomagnets for a broad range of biomedical applications are briefly discussed.

Advanced fully integrated radiofrequency/optical-coherence-tomography irrigated catheter for atrial fibrillation ablation

The inability of current catheter ablation procedures to accurately monitor lesion formation limits their safety and efficacy. An advanced fully integrated radiofrequency (RF)/optical coherence tomography (OCT) ablation catheter is developed, which enables real-time monitoring during ablation. An OCT fiber array is especially designed, developed and integrated into an off-the-shelf irrigated RF ablation catheter. In-vitro experimental studies performed on poultry and ovine hearts demonstrate the ability of the integrated RF/OCT system to provide information on the quality and orientation of catheter/wall contact. Experimental results show that adipose tissue can be accurately identified from normal myocardial tissue with 94% accuracy and lesion formation is monitored with an overall accuracy of 93%. The ability to predict pop events is also demonstrated, with an accuracy of 86%.

Animal Experiment of a Novel Neurointerventional Surgical Robotic System with Master-Slave Mode

In order to inspect and improve the system performance of the neuro-interventional surgical robot and its effectiveness and safety in clinical applications, we conducted ten animal experiments using this robotic system. Cerebral angiography was performed on ten experimental animals, and various mechanical performance indicators, operating time, X-ray radiation dosage to the experimental animals and the experimenter, and arterial damage in the experimental animals were recorded when the robotic system completed cerebral angiography. The results show that the robotic system can successfully complete the cerebral angiography surgery, and the mechanical performance is up to standard. The operating time is almost the same as the physician's operating time. And the mean X-ray radiation dosage received by the experimental animals and experimenter was 0.893 Gy and 0.0859 mSv, respectively. There were no complications associated with damage to the vascular endothelium. The robotic system can basically complete the relevant assessment indicators, and its system performance, effectiveness, and safety in clinical applications meet the standards, basically meeting the requirements of clinical applications of neurointerventional surgery.

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

Contact feedback improves 1-year outcomes of remote magnetic navigation-guided ischemic ventricular tachycardia ablation

INTRODUCTION

Remote magnetic navigation (RMN)-guided catheter ablation (CA) is a feasible treatment option for patients presenting with ischemic ventricular tachycardia (VT). Catheter-tissue contact feedback, enhances lesion formation and may consequently improve CA outcomes. Until recently, contact feedback was unavailable for RMN-guided CA. The novel e-Contact Module (ECM) was developed to continuously monitor and ensure catheter-tissue contact during RMN-guided CA.

OBJECTIVE

The present study aims to evaluate the effect of ECM implementation on acute and long-term outcomes in RMN-guided ischemic VT ablation.

METHOD

This retrospective, two-center study included consecutive ischemic VT patients undergoing RMN-guided CA from 2010 to 2017. Baseline clinical data, procedural data, including radiation times, and acute success rates were compared between CA procedures performed with ECM (ECM+) and without ECM (ECM-). One-year VT-free survival was analyzed using Cox-proportional hazards models, adjusting for potential confounders: age, left ventricular function, VT inducibility at baseline and substrate based ablation strategy.

RESULTS

The current study included 145 patients (ECM+ N = 25, ECM- N = 120). Significantly lower fluoroscopy times were observed in the ECM+ group (9.5 (IQR 5.3-13.5) versus 12.5 min (IQR 8.0-18.0), P = 0.025). Non-inducibility of the clinical VT at the end of procedure was observed in 92% ECM+ versus 72% ECM- patients (P = 0.19). ECM guidance was associated with significantly lower VT-recurrence rates during 1-year follow-up (16% ECM+ versus 40% ECM-; multivariable HR 0.29, 95%-CI 0.10-0.69, P = 0.021, reference group: ECM-).

CONCLUSION

Contact feedback by the ECM further decreases fluoroscopy exposure and improves VT-free survival in RMN-guided ischemic VT ablation.

Introducing a novel catheter-tissue contact feedback feature in robotic navigated catheter ablation: Utility, feasibility, and safety

Background

The quality of catheter–tissue contact is one of the most important determinants of catheter ablation (CA) success. The absence of catheter–tissue contact feedback has been regarded a major limitation of remote magnetic navigation (RMN)–guided CA. The e-Contact module (ECM) is a novel feature designed for RMN that measures the quality of catheter–tissue contact.

Objective

The purpose of this study was to describe the first clinical experience with this feature and to test its effect on procedural parameters and interference with other ablation equipment during CA procedures as well as its safety.

Methods

This was a prospective, single-center, 2-phase study investigating ECM use during complex RMN procedures in 30 patients. Impact of ECM on procedural parameters was evaluated in the feasibility phase (FP), and its interference with other equipment was tested in the interference phase (IP) using pacing maneuvers at 3 randomly selected right atrial sites. Intracardiac electrograms were evaluated for disturbances by 2 independent electrophysiologists.

Results

For FP, mean procedural time was 162 ± 66 minutes, fluoroscopy time 21 ± 9 minutes, and ablation time 34 ± 21 minutes. For IP, no significant differences in pacing capture or thresholds were found (ECM– vs ECM+: site 1: 2.05 vs 2.21 mA; P = .320; site 2: 2.15 vs 2.12 mA; P = .873; site 3: 2.51 vs 2.50 mA; P = .976). Electrogram disturbances did not significantly differ between ECM– and ECM+. No adverse events were reported.

Conclusion

The ECM is a novel catheter–tissue contact technology designed for RMN-guided CA. Our study suggests that this feature is feasible and does not interfere with other electrophysiology equipment while maintaining an excellent safety profile.

Liquid seal for compact micropiston actuation at the capillary tip

Actuators at the tip of a submillimetric catheter could facilitate in vivo interventional procedures at cellular scales by enabling tissue biopsy and manipulation or supporting active micro-optics. However, the dominance of frictional forces at this scale makes classical mechanism problematic. Here, we report the design of a microscale piston, with a maximum dimension of 150 μm, fabricated with two-photon lithography onto the tip of 140-μm-diameter capillaries. An oil drop method is used to create a seal between the piston and the cylinder that prevents any leakage below 185-mbar pressure difference while providing lubricated friction between moving parts. This piston generates forces that increase linearly with pressure up to 130 μN without breaking the liquid seal. The practical value of the design is demonstrated with its integration with a microgripper that can grasp, move, and release 50-μm microspheres. Such a mechanism opens the way to micrometer-size catheter actuation.

Progress in zero-fluoroscopy implantation of cardiac electronic device

Fluoroscopy is the imaging modality routinely used for cardiac device implantation. Due to the rising concern regarding the harmful effects of radiation exposure to both the patients and operation staffs, many efforts have been made to develop alternative techniques to achieve zero-fluoroscopy implantation. In this review, we describe the different methods aimed at avoiding the application of fluoroscopy in recent years, and evaluate their feasibility and safety in cardiac electronic device implantation.

Irrigated vs. Non-irrigated Catheters in the Ablation of Accessory Pathways

There is a paucity of data comparing irrigated to non-irrigated catheters in the ablation of accessory pathways (AP) in adult patients. Retrospective analysis of first-time AP ablations performed at our institution from May 2010 to June 2017. A total of 69 AP ablations were studied; irrigated catheters were used in 78.3% cases. Mean age was 40.9 ± 14.3 years and 56.7% were male. Among APs, 63.8% were left sided and 56.5% were concealed. The total procedure time was 232.0 ± 89.0 min, ablation time was 3.1 ± 5.1 min, and fluoroscopy time was 13.9 ± 15.4 min. The overall acute success rate of ablation was 62/69 (89%). Success rates trended higher with irrigated catheters in both groups and were significant for the population as a whole (94.4% vs. 73.3%, p = 0.04). Analyzing the entire cohort, success rates were significantly higher in ablations using irrigated catheters.

Adaptive Dynamic Control for Magnetically Actuated Medical Robots

In the present work we discuss a novel dynamic control approach for magnetically actuated robots, by proposing an adaptive control technique, robust towards parametric uncertainties and unknown bounded disturbances. The former generally arise due to partial knowledge of the robots' dynamic parameters, such as inertial factors, the latter are the outcome of unpredictable interaction with unstructured environments. In order to show the application of the proposed approach, we consider controlling the Magnetic Flexible Endoscope (MFE) which is composed of a soft-tethered Internal Permanent Magnet (IPM), actuated with a single External Permanent Magnet (EPM). We provide with experimental analysis to show the possibility of levitating the MFE - one of the most difficult tasks with this platform - in case of partial knowledge of the IPM's dynamics and no knowledge of the tether's behaviour. Experiments in an acrylic tube show a reduction of contact of the 32% compared to non-levitating techniques and 1.75 times faster task completion with respect to previously proposed levitating techniques. More realistic experiments, performed in a colon phantom, show that levitating the capsule achieves faster and smoother exploration and that the minimum time for completing the task is attained by the proposed approach.

A vascular interventional surgical robot based on surgeon's operating skills

Interventional surgery is widely used in the treatment of cardiovascular and cerebrovascular diseases, and the development of surgical robots can greatly reduce the fatigue and radiation risks brought to surgeons during surgery. In this paper, we present a novel interventional surgical robot which allows surgeons to fully use their operating skills during remote control. Fuzzy control theory is used to guarantee control precision during the master-slave operation. The safety force feedback control is designed based on the catheter and guidewire spring model, and the force-position control is designed to decrease the potential damage due to the control delay. This study first evaluates the force-position control strategy using a vascular model experiment, and then an in vivo experiment is used to evaluate the precision of the surgical robot controlling the catheter and guidewire to the designated position. The in vivo experiment results and surgeon's feedback demonstrate that the proposed surgical robot is able to perform complex remote surgery in clinical application. Graphical abstract Surgeons perform remote interventional animal surgery using interventional surgical robots.

Steerable catheters for minimally invasive surgery: a review and future directions

The steerable catheter refers to the catheter that is manipulated by a mechanism which may be driven by operators or by actuators. The steerable catheter for minimally invasive surgery has rapidly become a rich and diverse area of research. Many important achievements in design, application and analysis of the steerable catheter have been made in the past decade. This paper aims to provide an overview of the state of arts of steerable catheters. Steerable catheters are classified into four main groups based on the actuation principle: (1) tendon driven catheters, (2) magnetic navigation catheters, (3) soft material driven catheters (shape memory effect catheters, steerable needles, concentric tubes, conducting polymer driven catheters and hydraulic pressure driven catheters), and (4) hybrid actuation catheters. The advantages and limitations of each of them are commented and discussed in this paper. The future directions of research are summarized.

Robotic navigation shows superior improvement in efficiency for atrial fibrillation ablation

Background

Because of the expanding atrial fibrillation (AF) burden, AF catheter ablation (CA) techniques have to become more efficient. Efficient AF CA procedures are characterized by successful pulmonary vein isolation (PVI) within reasonable procedure time. Currently there are many PVI techniques available and all show substantial improvements over time. However, the magnitude of improvement in procedural efficiency has not yet been compared between different techniques. The aim of this study was to compare efficiency improvement between manually (MAN) guided, cryoballoon (CB) and remote magnetic navigation (RMN) guided PVI.

Methods

A total of 221 patients were included in this retrospective study. Procedural parameters of 115 patients treated with first-generation PVI techniques (MAN-1, CB-1, RMN-1) performed in 2010, were compared to 106 patients who were treated with the latest, second generation techniques (MAN-2, CB-2, RMN-2). Efficiency was characterized by the following parameters: total ablation time, total procedure time, first pass isolation (FPI) (i.e. successful isolation after the first pulmonary vein (PV) encirclement) and touch-up rates.

Results

Every technique showed significant improvement of procedure times from the first to the second generation (P<0.001). In-between second generation techniques, the procedure times were comparable. The greatest magnitude of procedure time improvement was observed within the RMN groups (∆-180min), which was significantly greater compared to CB (∆-48 min, P<0.001) and MAN (∆-98min, P=0.011) groups. The highest FPI rates were observed in RMN-2 (78% and 74%; left and right PVs respectively), which was significantly higher compared to other techniques (MAN-2: 24% and 24%; CB-2: 50% and 48%; P<0.001).

Conclusions

The highest magnitude of efficiency improvement was detected in RMN guided PVI.

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

Atrioventricular node reentrant tachycardia: Remote magnetic navigation ablation versus manual ablation - impact on operator fluoroscopy time

INTRODUCTION AND AIMS

Remote magnetic navigation systems have demonstrated benefits in the ablation of difficult substrates. Their role in the ablation of atrioventricular nodal reentrant tachycardia (AVNRT), however, has only been studied in small patient series. The aim of this study was to compare the results of AVNRT ablation using magnetic navigation, in a center where every procedure is performed with this system, with manual ablation.

METHODS

We selected 139 consecutive patients undergoing AVNRT ablation with magnetic navigation by a single operator between January 2009 and June 2016 and compared them to a group of 101 consecutive patients undergoing manual ablation in the same period by the same operator in another hospital. The methodology was the same in both groups. Success rates, complications, procedure time, radiofrequency time, total and operator fluoroscopy time, and recurrence rates were compared.

RESULTS

There were no differences in success and complication rates. Procedure and total fluoroscopy times were not significantly different, but operator fluoroscopy time was significantly shorter with the magnetic navigation system (2.4±1.5 min vs. 7.2±4 min; p<0.001). The recurrence rate was higher in the manual group, although without statistical significance.

CONCLUSIONS

The ablation of AVNRT with magnetic navigation is feasible using the same methodology as for manual ablation. Success and complication rates were similar. Operator fluoroscopy time was significantly less with the magnetic navigation system.

Magnetic Levitation for Soft-Tethered Capsule Colonoscopy Actuated With a Single Permanent Magnet: A Dynamic Control Approach

The present letter investigates a novel control approach for magnetically driven soft-tethered capsules for colonoscopy-a potentially painless approach for colon inspection. The focus of this work is on a class of devices composed of a magnetic capsule endoscope actuated by a single external permanent magnet. Actuation is achieved by manipulating the external magnet with a serial manipulator, which in turn produces forces and torques on the internal magnetic capsule. We propose a control strategy which, counteracting gravity, achieves levitation of the capsule. This technique, based on a nonlinear backstepping approach, is able to limit contact with the colon walls, reducing friction, avoiding contact with internal folds, and facilitating the inspection of nonplanar cavities. The approach is validated on an experimental setup, which embodies a general scenario faced in colonoscopy. The experiments show that we can attain 19.5% of contact with the colon wall, compared to the almost 100% of previously proposed approaches. Moreover, we show that the control can be used to navigate the capsule through a more realistic environment-a colon phantom-with reasonable completion time.

The Use of Innovative Technologies to Guide Cardiac Procedures

The advantages of intracardiac echocardiography (ICE) include shorter procedure times, reduced radiation exposure and the elimination of the need for general anesthesia. It is also effective in the safe performance of transseptal punctures. These have led to its increasing use in electrophysiology (EP) procedures. The use of ICE provides unrestricted access to the cardiac anatomy and guides interventional cardiac procedures by providing high-quality images of intracardiac structures and devices. As well as their use as imaging in catheter ablation of atrial fibrillation and other arrhythmias, ICE ultrasound catheters may be used in cardiac valve repair and the closure of atrial septal defects (ASDs). Integration of ICE catheters with electroanatomical mapping systems that construct three dimensional (3D) images have further increased the application of the technique. The use of magnetic navigation systems (MNS) have conferred further advantages including reduced exposure to fluoroscopy and increased operator comfort. This article presents four clinical cases and reviews clinical studies of these techniques.

Remote vs. conventional navigation for catheter ablation of atrial fibrillation: insights from prospective registry data

BACKGROUND

Robotic (RNS) or magnetic navigation systems (MNS) are available for remotely performed catheter ablation for atrial fibrillation (AF).

OBJECTIVE

The present study compares remotely assisted catheter navigation (RAN) to standard manual navigation (SMN) and both systems amongst each other.

METHODS

The analysis is based on a sub-cohort enrolled by five hospitals from the multicenter German ablation Registry.

RESULTS

Out of 2442 patients receiving catheter ablation of AF, 267 (age 61.4 ± 10.4, 69.7% male) were treated using RAN (RNS n = 187, 7.7% vs. MNS n = 80, 3.3%). Fluoroscopy time [RNS median 17 (IQR 12-25) min vs. MNS 22 (16-32) min; p < 0.001] and procedure duration [RNS 180 (145-220) min vs. MNS 265 (210-305) min; p < 0.001] were significantly different. Comparing RAN (11%) to SMN (89%) fluoroscopy time (RAN 19 (13-27) min, vs. SMN 25 (16-40) min; p < 0.001), energy delivery (RAN 3168 (2280-3840) s vs. SMN 2640 (IQR 1799-3900) s; p = 0.008) and procedure duration [RAN 195 (150-255) min vs. SMN 150 (120-150) min; p = 0.001] differed significantly. In terms of acute and 12 months outcome, no differences were seen between the two systems or in comparison to SMN.

CONCLUSION

AF ablation can be performed safely, with high acute success rates using RAN. RNS results in less fluoroscopy burden and shorter procedure durations. Compared to SMN, a reduced fluoroscopy burden, prolonged procedure and ablation duration were observed using RAN. Overall, the number of RAN procedures is small suggesting low impact on clinical routine of AF ablation.

Compensatory force measurement and multimodal force feedback for remote-controlled vascular interventional robot

Minimally invasive vascular interventional surgery is widely used and remote-controlled vascular interventional surgery robots (RVIRs) are being developed to reduce the occupational risk of the intervening physician in minimally invasive vascular interventional surgeries. Skilled surgeon performs surgeries mainly depending on the detection of collisions. Inaccurate force feedback will be difficult for surgeons to perform surgeries or even results in medical accidents. In addition, the surgeon cannot quickly and easily distinguish whether the proximal force exceeds the safety threshold of blood vessels or not, and thus it results in damage to the blood vessels. In this paper, we present a novel method comprising compensatory force measurement and multimodal force feedback (MFF). Calibration experiments and performance evaluation experiments were carried out. Experimental results demonstrated that the proposed method can measure the proximal force of catheter/guidewire accurately and assist surgeons to distinguish the change of proximal force more easily. This novel method is suitable for use in actual surgical operations.

Initial Clinical Trial of Robot of Endovascular Treatment with Force Feedback and Cooperating of Catheter and Guidewire

To evaluate the feasibility and safety of the robot of endovascular treatment (RobEnt) in clinical practice, we carried out a cerebral angiography using this robot system. We evaluated the performance of application of the robot system to clinical practice through using this robotic system to perform the digital subtraction angiography for a patient who was suspected of suffering intracranial aneurysm. At the same time, through comparing the postoperative head nuclear magnetic and blood routine with the preoperative examination, we evaluated the safety of application of the robot system to clinical practice. We performed the robot system to complete the bilateral carotid artery and bilateral vertebral arteriography. The results indicate that there was no obvious abnormality in the patient's cerebral artery. No obvious abnormality was observed in the examination of patients' check-up, head nuclear magnetism, and blood routine after the digital subtraction angiography. From this clinical trial, it can be observed that the robot system can perform the operation of cerebral angiography. The robot system can basically complete the related observation indexes, and its accuracy, effectiveness, stability, and safety basically meet the requirements of clinical application in neurointerventional surgery.

Long-term clinical outcomes of magnetically navigated rotor ablation as an adjunct to conventional pulmonary vein isolation

Aims

The objective of this study is to evaluate the outcomes of magnetically guided ablation of atrial fibrillation (AF) rotors in conjunction with magnetically guided pulmonary vein isolation (PVI) in a large consecutive series of patients.

Methods and results

A total of 110 consecutive patients with drug-refractory AF underwent rotor ablation followed by conventional PVI and ablation of other spontaneous arrhythmias, all of which were performed with remote magnetic navigation (RMN). The patients were followed to assess the recurrence of atrial arrhythmia. Patients had a mean age of 62.5 ± 9.9 years, 64.5% had persistent AF, and 36.4% had a prior failed PVI. All patients had mapped rotors (3.9 ± 1.5 per patient), with right atrial (RA) rotors in 77.3% (85/110) of patients. After a mean follow-up of 17.6 ± 9.5 months, 90.9% (100/110) were in stable sinus rhythm including patients on previously ineffective antiarrhythmic drugs (AADs). 69.1% (76/110) were in stable sinus rhythm without any AADs. Outcome did not differ between patients with persistent or paroxysmal AF (69.2% vs. 69.0%; P = 0.75), failed prior ablation or those undergoing an initial ablation (77.5% vs. 64.3%; P = 0.193), or patients with and without intra-procedural AF termination (67.3% vs. 70.5%; P = 0.723).

Conclusion

Ablation of rotors in combination with PVI using RMN was associated with a high success rate in this large cohort of consecutive patients. Significant proportion of patients exhibited RA rotors, which was associated with persistent AF, obstructive sleep apnoea, and obesity.

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.

Safety and feasibility of atrial fibrillation ablation using Amigo® system versus manual approach: A pilot study

BACKGROUND

The Amigo® Remote Catheter System is a relatively new robotic system for catheter navigation. This study compared feasibility and safety using Amigo (RCM) versus manual catheter manipulation (MCM) to treat paroxysmal atrial fibrillation (PAF). Contact force (CF) and force-time integral (FTI) values obtained during pulmonary vein isolation (PVI) ablation were compared.

METHODS

Forty patients were randomly selected for either RCM (20) or MCM (20). All were studied with the Thermocool® SmartTouch® force-sensing catheter (STc). Contact Force (CF), Force Time Integral (FTI) and procedure-related data, were measured/stored in the CARTO®3.

RESULTS

All cases achieved complete PVI without major complications. Mean CF was significantly higher in the RCM group (13.3 ± 7.7 g in RCM vs. 12.04 ± 7.42 g in MCM p < 0.001), as was overall mean FTI (425.6 gs ± 199.6 gs with RCM and 407.5 gs ± 288.0 gs in MCM (p = 0.007) and was more likely to fall into the optimal FTI range (400-1000) using RCM (66.1% versus 49.1%, p < 0.001). FTI was significantly more likely to fall within the optimal range in each PV, as was CF within its optimal range in the right PVs, but trended higher in the left PVs. Freedom from atrial tachyarrhythmia was 90.0% for the RCM and 70.0% for the MCM group (p = 0,12) at 540 days follow-up.

CONCLUSIONS

This pilot study suggests that use of the Amigo RCM system, with STc catheter, seems to be safe and effective for PVI ablation in paroxysmal AF patients. A not statistically significant favorable trend was observed for RCM in term of AF-free survival.

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.

Estimation-Based Control of a Magnetic Endoscope without Device Localization

Magnetically controlled catheters and endoscopes can improve minimally invasive procedures as a result of their increased maneuverability when combined with modern magnetic steering systems. However, such systems have two distinct shortcomings: they require continuous information about the location of the instrument inside the human body and they rely on models that accurately capture the device behavior, which are difficult to obtain in realistic settings. To address both of these issues, we propose a control algorithm that continuously estimates a magnetic endoscope’s response to changes in the actuating magnetic field. Experiments in a structured visual environment show that the control method is able to follow image-based trajectories under different initial conditions with an average control error that measures 1.8 % of the trajectory length. The usefulness for medical procedures is demonstrated with a bronchoscopic inspection task. In a proof-of-concept study, a custom 2[Formula: see text]mm diameter miniature camera endoscope is navigated through an anatomically correct lung phantom in a clinician-controlled manner. This represents the first demonstration of the controlled manipulation of a magnetic device without localization, which is critical for a wide range of medical procedures.

The Amigo™ Remote Catheter System: From Concept to Bedside

Radiation exposure is a serious concern during fluoroscopic procedures, including electrophysiology (EP) studies and radiofrequency catheter ablation of arrhythmias. Operators typically don lead aprons to protect themselves from radiation, but wearing lead can result in greater fatigue and orthopedic injury during long procedures. To address this problem, two robotic catheter systems (RCS) have previously been introduced on the market, the Niobe^® (Stereotaxis Inc., St. Louis, MO, USA) and Sensei^® X (Hansen Medical, Inc., Mountain View, CA, USA) systems. However, the widespread adoption of these systems has been limited by both cost and ease of use. In contrast, the Amigo™ RCS (Catheter Precision, Inc., Mount Olive, NJ, USA) was developed to provide a simple, lower profile, and less expensive remote catheter manipulation solution. Approved by the United States Food and Drug Administration (FDA), this technology allows for operators to remotely manipulate electrophysiology (EP) catheters from outside the fluoroscopy field. Notably, the Amigo™ RCS (Catheter Precision, Inc., Mount Olive, NJ, USA) first underwent an early study in dogs in 2008 to demonstrate its safety and efficacy in an animal model. After a clinical trial evaluating its safety and mapping capabilities in humans was completed in 2010, the Amigo™ RCS (Catheter Precision, Inc., Mount Olive, NJ, USA) underwent several scientific studies to examine its ability to assist in the mapping and ablation of various arrhythmias in comparison with the conventional manual approach. The Amigo™ RCS (Catheter Precision, Inc., Mount Olive, NJ, USA) achieved mapping and ablation success rates that were similar to those achieved with manual catheter manipulation, and no complications due to its use were observed. It was approved by the FDA for use in diagnostic EP studies of the right atrium and ventricle in 2012, with this indication later expanded in 2014 to include radiofrequency ablations. The device is currently compatible with the Blazer™ (Boston Scientific, Natick, MA, USA) and EZ STEER™ (Biosense Webster, Inc., Diamond Bar, CA, USA) catheter handles. Here, we present a clinical report in which the Amigo™ RCS (Catheter Precision, Inc., Mount Olive, NJ, USA) was employed to map and ablate symptomatic supraventricular tachycardia. Dr. Cohen’s clinical experience with this robotic system is also reviewed.

Iterative Jacobian-Based Inverse Kinematics and Open-Loop Control of an MRI-Guided Magnetically Actuated Steerable Catheter System

This paper presents an iterative Jacobian-based inverse kinematics method for an MRI-guided magnetically-actuated steerable intravascular catheter system. The catheter is directly actuated by magnetic torques generated on a set of current-carrying micro-coils embedded on the catheter tip, by the magnetic field of the magnetic resonance imaging (MRI) scanner. The Jacobian matrix relating changes of the currents through the coils to changes of the tip position is derived using a three dimensional kinematic model of the catheter deflection. The inverse kinematics is numerically computed by iteratively applying the inverse of the Jacobian matrix. The damped least square method is implemented to avoid numerical instability issues that exist during the computation of the inverse of the Jacobian matrix. The performance of the proposed inverse kinematics approach is validated using a prototype of the robotic catheter by comparing the actual trajectories of the catheter tip obtained via open-loop control with the desired trajectories. The results of reproducibility and accuracy evaluations demonstrate that the proposed Jacobian-based inverse kinematics method can be used to actuate the catheter in open-loop to successfully perform complex ablation trajectories required in atrial fibrillation ablation procedures. This study paves the way for effective and accurate closed-loop control of the robotic catheter with real-time feedback from MRI guidance in subsequent research.

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.

Catheter Ablation: General Principles and Advances

Besides antiarrhythmic medication, there are now very good options for a potentially curative therapy by catheter ablation targeting the origin of the underlying arrhythmias in patients with complex congenital heart disease. Three-dimensional (3D) reconstruction of tomographic imaging (MRI or computed tomography) is helpful to understand the underlying cardiac anatomy, identify the most likely target chamber, and help with planning access. Use of the available 3D mapping systems (sequential or simultaneous acquisition) and (if available) more advanced navigation systems, such as remote magnetic navigation, can improve the acute and long-term outcomes of catheter ablation in congenital heart disease.