Abstract 11194: Reducing Arm Muscle Activation by Using an Ablation Catheter Torque Tool: Electromyographic Analysis and User Perception

Background: Cardiac ablation catheters are small in diameter and require significant finger dexterity and grip strength to maintain stability and maneuver safely. We designed a catheter torque tool to reduce the muscle activation required to manipulate cardiac ablation catheters and improve user perception of task workload. Objective: The purpose of this study was to evaluate muscle usage and user perception when completing a simulated ablation task with and without the use of a novel ablation catheter torque tool. Methods: Participants, comprised of cardiology attendings and fellows, were fitted with surface electromyographic (EMG) sensors on 6 key muscle groups in the left hand and forearm. Maximum voluntary contraction (MVC) was collected for equal comparison among participants. A standard ablation catheter was inserted into a pediatric cardiac ablation simulator and subjects navigated the catheter tip to 6 specific electrophysiologic targets including a 1-minute simulated radiofrequency lesion. EMG activity normalized to percentage of MVC was collected throughout the task. The task was repeated 4 times, twice with and twice without the torque tool, in randomized order. A NASA Task Load Index (TLX) survey was completed by the participant at the conclusion each task. Results: Thirteen participants completed the study. Using Wilcoxon’s test, there was a significant difference (P &lt; 0.01) in mean percent of MVC in 4 of the 6 muscle groups when comparing bare catheter versus catheter with torque tool: abductor pollicis, brachioradialis, flexor carpi ulnaris, and extensor carpi radialis. The total expended energy for the abductor pollicis (P &lt; 0.01) and extensor carpi radialis (P = 0.02) were significantly reduced. Perceived physical demand, effort, and frustration were also significantly reduced when using the torque tool (P &lt; 0.01). Conclusions: Use of our novel catheter torque tool reduced the amount of muscle activation necessary to manipulate an ablation catheter during a simulated ablation task. Users’ perceived physical demand, effort, and frustration were less when the tool was used. This tool may improve catheter stability, increase procedure safety, and reduce operator stress and muscle fatigue when performing catheter ablation procedures. </jats:p

Percutaneous epicardial pacing in infants using direct visualization: A feasibility animal study

BACKGROUND: Pacemaker implantation in infants and small children is limited to epicardial lead placement via open chest surgery. We propose a minimally invasive solution using a novel percutaneous access kit. OBJECTIVE: To evaluate the acute safety and feasibility of a novel percutaneous pericardial access tool kit to implant pacemaker leads on the epicardium under direct visualization. METHODS: A custom sheath with optical fiber lining the inside wall was built to provide intrathoracic illumination. A Veress needle inside the illumination sheath was inserted through a skin nick just to the left of the xiphoid process and angled toward the thorax. A needle containing a fiberscope within the lumen was inserted through the sheath and used to access the pericardium under direct visualization. A custom dilator and peel-away sheath with pre-tunneled fiberscope was passed over a guidewire into the pericardial space via modified Seldinger technique. A side-biting multipolar pacemaker lead was inserted through the sheath and affixed against the epicardium. RESULTS: Six piglets (weight 3.7-4.0 kg) had successful lead implantation. The pericardial space could be visualized and entered in all animals. Median time from skin nick to sheath access of the pericardium was 9.5 (interquartile range [IQR] 8-11) min. Median total procedure time was 16 (IQR 14-19) min. Median R wave sensing was 5.4 (IQR 4.0-7.3) mV. Median capture threshold was 2.1 (IQR 1.7-2.4) V at 0.4 ms and 1.3 (IQR 1.2-2.0) V at 1.0 ms. There were no complications. CONCLUSION: Percutaneous epicardial lead implantation under direct visualization was successful in six piglets of neonatal size and weight with clinically acceptable acute pacing parameters

Supervised autonomous robotic soft tissue surgery.

Supervised autonomous in vivo robotic surgery is possible on soft tissues and outperforms standard clinical techniques in a dynamic preclinical environment.</jats:p

Design and Functionality of a Multilumen Thoracic Access Port for Pericardial Access Under Direct Visualization

Abstract Small vasculature, venous obstruction, or congenital anomalies can preclude transvenous access to the heart, often resulting in open chest surgery to implant cardiac therapy leads for pacing, defibrillation, or cardiac resynchronization. A minimally invasive approach under direct visualization could reduce tissue damage, minimize pain, shorten recovery time, and obviate the need for fluoroscopy. Therefore, PeriPath was designed as a single-use, low-cost pericardial access tool based on clinical requirements. Its mechanical design aids in safe placement of conductive leads to the pericardium using a modified Seldinger technique. The crossed working channels provide an optimal view of the surgical field under direct visualization. Finite element analysis (FEA) confirms that the device is likely not to fail under clinical working conditions. Mechanical testing demonstrates that the tensile strength of its components is sufficient for use, with minimal risk of fracture. The PeriPath procedure is also compatible with common lead implantation tools and can be readily adopted by interventional cardiologists and electrophysiologists, allowing for widespread implementation. Prior animal work and a physician preliminary validation study suggest that PeriPath functions effectively for minimally invasive lead implantation procedures.</jats:p

Role of surgeon intuition and computer-aided design in Fontan optimization: a computational fluid dynamics simulation study

OBJECTIVE: Customized Fontan designs, generated by computer-aided design (CAD) and optimized by computational fluid dynamics simulations, can lead to novel, patient-specific Fontan conduits unconstrained by off-the-shelf grafts. The relative contributions of both surgical expertise and CAD to Fontan optimization have not been addressed. In this study, we assessed hemodynamic performance of Fontans designed by both surgeon\u27s unconstrained modeling (SUM) and by CAD. Methods: Ten cardiac magnetic resonance imaging datasets were used to create 3-dimensional (3D) models of Fontans. Baseline computational fluid dynamics simulations assessed Fontan indexed power loss (iPL), hepatic flow distribution, and percentage of conduit surface area with abnormally low wall shear stress for venous flow (\u3c1 dyne/cm2). Fontans not meeting thresholds were redesigned using 2 methods: SUM (ie, original venous anatomy without the Fontan was 3D printed and sent to surgeon for Fontan redesign with clay modeling) and CAD (ie, the same 3D geometry was sent to engineers for iterative Fontan redesign guided by computational fluid dynamics). Both groups were blinded to each other\u27s results. RESULTS: Eight Fontans were redesigned by SUM and CAD methods. Both SUM and CAD redesigns met iPL thresholds. SUM had lower iPL, whereas CAD demonstrated balanced hepatic flow distribution and lower wall shear stress percentage. Wall shear stress percentage shared an inverse relationship with iPL, preventing oversized Fontan designs. CONCLUSIONS: Customized Fontan conduits with low iPL can be created by either a surgeon or CAD. CAD can also improve hepatic flow distribution and prevent oversized Fontan designs. Future studies should investigate workflows that combine SUM and CAD to optimize Fontan conduits

Design and Evaluation of an Eye Mountable AutoDALK Robot for Deep Anterior Lamellar Keratoplasty

Partial-thickness corneal transplants using a deep anterior lamellar keratoplasty (DALK) approach has demonstrated better patient outcomes than a full-thickness cornea transplant. However, despite better clinical outcomes from the DALK procedure, adoption of the technique has been limited because the accurate insertion of the needle into the deep stroma remains technically challenging. In this work, we present a novel hands-free eye mountable robot for automatic needle placement in the cornea, AutoDALK, that has the potential to simplify this critical step in the DALK procedure. The system integrates dual light-weight linear piezo motors, an OCT A-scan distance sensor, and a vacuum trephine-inspired design to enable the safe, consistent, and controllable insertion of a needle into the cornea for the pneumodissection of the anterior cornea from the deep posterior cornea and Descemet’s membrane. AutoDALK was designed with feedback from expert corneal surgeons and performance was evaluated by finite element analysis simulation, benchtop testing, and ex vivo experiments to demonstrate the feasibility of the system for clinical applications. The mean open-loop positional deviation was 9.39 µm, while the system repeatability and accuracy were 39.48 µm and 43.18 µm, respectively. The maximum combined thrust of the system was found to be 1.72 N, which exceeds the clinical penetration force of the cornea. In a head-to-head ex vivo comparison against an expert surgeon using a freehand approach, AutoDALK achieved more consistent needle depth, which resulted in fewer perforations of Descemet’s membrane and significantly deeper pneumodissection of the stromal tissue. The results of this study indicate that robotic needle insertion has the potential to simplify the most challenging task of the DALK procedure, enable more consistent surgical outcomes for patients, and standardize partial-thickness corneal transplants as the gold standard of care if demonstrated to be more safe and more effective than penetrating keratoplasty