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Abstract Background There is a scarcity of evidence regarding the potential relationship between the size and location of necrotic lesions, which must be understood to provide optimal joint-preserving treatment. The purpose of this study was to characterize the distribution patterns of necrotic lesions of varying sizes in early-stage osteonecrosis of femoral head (ONFH) with the use of three-dimensional mapping. Methods We retrospectively evaluated clinical CT images of the hips that were performed in the Third Hospital of Hebei Medical University from January 2018 to December 2022 and collected all CT images diagnosed with stage I and II ONFH. Three-dimensional structures that included both necrotic lesions and normal areas of the femoral heads were reconstructed and divided into eight regions to record their size and location. CT images for all lesions were superimposed onto a standard template, and three-dimensional mapping was created to determine the presence of concentrated areas of lesions. Results In a cohort of 143 patients with stage I and II ONFH, a total of 150 hips were reviewed. For lesions with less than 15% of the femoral head volume, necrotic lesions predominantly involve regions I, III, and V, with region I showing concentration. For lesions with volumes ranging from 15 to 30%, necrotic lesions exhibited a wider distribution across regions I, II, III, IV, V, and VII, with significant concentrations in regions I, III, and V. For lesions exceeding 30% of the femoral head volume, the necrotic lesions were extensively distributed across nearly the entire femoral head, with a notable expansion of the concentrated necrotic areas. Conclusions The distribution of necrotic lesions varies with lesion size, with smaller lesions primarily concentrated in the anterior and medial regions of the femoral head, particularly in the anterosuperior region, while larger lesions expand to the lateral and inferior regions. These findings enhance existing classification systems and provide crucial insights for guiding hip-preserving surgical planning and approaches.

Introduction: The novel cryoballoon with 28 mm or 31 mm adjustable diameters, aims to achieve a wide antral pulmonary vein isolation (PVI). However, the distribution of antral lesions and their variations based on left atrial (LA) remodeling require further clarification. Methods: We evaluated 22 patients (67 [59.5–74.8] years, 19 males) who underwent PVI of atrial fibrillation (AF) (13 paroxysmal AF [PAF] and 9 non‐PAF) using size‐adjustable cryoballoons. LA electro‐anatomical mapping was performed post‐PVI with three‐dimensional mapping systems. We assessed the shapes of the LA and pulmonary veins (PVs) and the distribution of isolated areas (IAs), comparing the results between PAF and non‐PAF patients. Results: In the left PVs (LPVs), the distance between the PV orifice and IA edge (PVos‐IA) was larger on the roof and posterior segments (~15 mm) but relatively smaller on the anterior segment near the PV ridge (<10 mm). For the right PVs (RPVs), it was more extensive in the posterior segment (10–15 mm). Comparing PAF and non‐PAF, there were no significant differences in the PVos‐IA except for the right posterior‐carina segment, antrum IA (LPVs: 5.9 ± 1.6 vs. 5.8 ± 0.8 cm², p =.81; RPVs: 4.8 ± 2.3 vs. 4.8 ± 1.2 cm², p =.81), distances between the right and left IAs on the LA posterior wall (LAPW), and un‐isolated LAPW area (9.0 ± 4.9 vs. 9.9 ± 2.5 cm², p =.62). No individual PVIs were observed in either group. Two patients exhibited overlapping IAs on the roof, and one patient who underwent 31 mm balloon applications for all PVs exhibited an LAPW isolation. Conclusion: The size‐adjustable cryoballoon achieved a wide antral PVI even in non‐PAF patients. [ABSTRACT FROM AUTHOR]

In this study, we analyzed the success rate of cryoablation for septal accessory pathways in pediatric patients using a three-dimensional mapping method. 102 pediatric patients underwent septal accessory pathway ablation, with cryoablation performed for an average of 4 minutes in each application using a 6 or 8-mm cryoablation catheter with three-dimensional mapping. The mean age and weight of the patients were 11.3 ± 5.4 years and 35.6 ± 14.3 kg, respectively. Most patients (70.6%) had a manifest accessory pathway, while 29.4% had a concealed one. The locations of the accessory pathways were anteroseptal (37.3%), midseptal (22.5%), and posteroseptal (40.2%). The successful ablation effect time was 8.9 ± 7.3 seconds. Two patients experienced early recurrence on the day after the procedure, but the second procedure was successful in both cases. Throughout the course of the procedure, nodal rhythm manifested in five individuals, representing 4.9% of the sample; incomplete right bundle branch block was observed in four patients, accounting for 3.9% of the cohort; prolongation of the PR interval occurred in four cases, making up 3.9% of the total; and second-degree atrioventricular block was identified in two patients, constituting 1.9% of the study population. These electrocardiographic (ECG) changes returned to normal the following day, except for two patients with right bundle branch block, whose ECG findings returned to normal within the first month. The mean follow-up period was 56.71 ± 29.5 months, during which recurrence was observed in two patients with manifest preexcitation in the first and third months after the procedure. However, a second ablation procedure was successfully performed in these patients, and no second recurrence was detected during the follow-up period. Cryoablation with electroanatomic mapping system is a safe and effective procedure with high success rates in pediatric patients with septal and perinodal accessory pathways. [ABSTRACT FROM AUTHOR]

Navigation and autonomous operation in farmland or greenhouse environments present significant challenges for agricultural mobile robots on account of unstructured scene conditions and complex task requirements. The immersive interfaces based on human–robot interaction have been extensively developed, which bridge the high‐level decision of human beings and the precise sensing and high motion ability of robots. In this study, we propose a human–robot interaction framework based on three‐dimensional mapping and virtual reality (VR) visualization. On the construction client, dense three‐dimensional point‐cloud maps are created based on the simultaneous localization and mapping real‐time appearance‐based mapping algorithm with a Kinect‐style depth camera. Subsequently, point‐cloud filtering and mesh creation methods are introduced for postprocessing the map models. A data communication network is employed to transmit the optimized models to the VR‐based exploration client. Utilizing VR visualization, the operator can gain an intuitive and comprehensive understanding of the environments to be explored. The three‐dimensional agricultural scenes are mapped into VR models through the system, which can combine the physical worlds with the VR spaces in a better manner. Compared with the video streaming‐based method for three‐dimensional mapping, the map models with colors and textures are entirely displayed in the VR headset, thus providing robust and global human–robot interaction interfaces and enhancing the immersive exploration for human beings to a considerable extent. Experimental results indicate that the three‐dimensional map models exhibit relatively sufficient construction integrity and yield favorable optimization effects. Additionally, according to a user questionnaire survey, immersive VR‐based interfaces can be more effectively utilized for the three‐dimensional mapping of mobile robots. Research evidence and results demonstrate that our proposed system framework offers positive assistance and support for enhancing human–robot interaction and executing specific robotic tasks in unstructured field agricultural environments. Code implementation and related data sets are shared at the link https://github.com/WangDongBUAA/Mapping_Interfacing. [ABSTRACT FROM AUTHOR]

Background: There is a scarcity of evidence regarding the potential relationship between the size and location of necrotic lesions, which must be understood to provide optimal joint-preserving treatment. The purpose of this study was to characterize the distribution patterns of necrotic lesions of varying sizes in early-stage osteonecrosis of femoral head (ONFH) with the use of three-dimensional mapping. Methods: We retrospectively evaluated clinical CT images of the hips that were performed in the Third Hospital of Hebei Medical University from January 2018 to December 2022 and collected all CT images diagnosed with stage I and II ONFH. Three-dimensional structures that included both necrotic lesions and normal areas of the femoral heads were reconstructed and divided into eight regions to record their size and location. CT images for all lesions were superimposed onto a standard template, and three-dimensional mapping was created to determine the presence of concentrated areas of lesions. Results: In a cohort of 143 patients with stage I and II ONFH, a total of 150 hips were reviewed. For lesions with less than 15% of the femoral head volume, necrotic lesions predominantly involve regions I, III, and V, with region I showing concentration. For lesions with volumes ranging from 15 to 30%, necrotic lesions exhibited a wider distribution across regions I, II, III, IV, V, and VII, with significant concentrations in regions I, III, and V. For lesions exceeding 30% of the femoral head volume, the necrotic lesions were extensively distributed across nearly the entire femoral head, with a notable expansion of the concentrated necrotic areas. Conclusions: The distribution of necrotic lesions varies with lesion size, with smaller lesions primarily concentrated in the anterior and medial regions of the femoral head, particularly in the anterosuperior region, while larger lesions expand to the lateral and inferior regions. These findings enhance existing classification systems and provide crucial insights for guiding hip-preserving surgical planning and approaches. [ABSTRACT FROM AUTHOR]

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Background Double-wave macrore-entry is a rare mechanism of atrial tachycardia with limited documentation in the literature. We present a three-dimensional documentation of a double-wave 'typical' atrial flutter in a patient with extensive atrial cardiomyopathy. Case summary A 78-year-old female with a history of atrial cardiomyopathy and dual-chamber pacemaker for sinus node disease presented with palpitations and incessant atrial flutter. Electrophysiological study revealed a regular tachycardia with a cycle length (TCL) of 230 ms, with proximal to distal coronary sinus (CS) activation. Three-dimensional mapping identified two independent wavefronts circulating the cavotricuspid isthmus (CTI), each with a TCL of 460 ms. Cavotricuspid isthmus ablation resulted in conversion into a distinct tachycardia with left atrial roof origin. Linear ablation in this location slowed the TCL to 435 ms with concentric CS activation and another CTI dependent atrial flutter was mapped, this time with only one wavefront of activation. Further ablation with a second, more lateral, line in the CTI led to tachycardia interruption. Given the extensive atrial scarring and high arrhythmic recurrence risk, atrioventricular node ablation was performed. Discussion Double-wave re-entrant tachycardias were primarily observed in experimental models, precipitating acceleration of ventricular and supraventricular tachycardias via extrastimulation. In our case, there is documentation of a spontaneous double-wave of activation around the CTI, representing the first documented double-wave 'typical' atrial flutter. Unlike other cases in the literature, the two wavefronts were equidistant, which resulted in a regular tachycardia with TCL that was half of the single-wave cycle length. Three-dimensional propagation mapping was essential to visualize the two distinct wavefronts. [ABSTRACT FROM AUTHOR]

Introduction: Mapping system is useful in ablation of atrioventricular nodal reentry tachycardia (AVNRT) and localization of anatomic variances. Voltage mapping identifies a low voltage area in the Koch triangle called low‐voltage‐bridge (LVB); propagation mapping identifies the collision point (CP) of atrial wavefront convergence. We conducted a prospective study to evaluate the relationship between LVB and CP with successful site of ablation and identify standard value for LVB. Materials and Methods: Three‐dimensional (3D) maps of the right atria were constructed from intracardiac recordings using the ablation catheter. Cut‐off values on voltage map were adjusted until LVB was observed. On propagation map, atrial wavefronts during sinus rhythm collide in the site representing CP, indicating the area of slow pathway conduction. Ablation site was selected targeting LVB and CP site, confirmed by anatomic position on fluoroscopy and atrioventricular ratio. Results: Twenty‐seven consecutive patients were included. LVB and CP were present in all patients. Postprocedural evaluation identified standard cut‐off of 0.3−1 mV useful for LVB identification. An overlap between LVB and CP was observed in 23 (85%) patients. Procedure success was achieved in all patient with effective site at first application in 22 (81%) patients. There was a significant correlation between LVB, CP, and the site of effective ablation (p = .001). Conclusion: We found correlation between LVB and CP with the site of effective ablation, identifying a voltage range useful for standardized LVB identification. These techniques could be useful to identify ablation site and minimize radiation exposure. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) mapping of the ventricular conduction system is challenging. The purpose of this study was to use ripple mapping to distinguish conduction system activation to that of adjacent myocardium in order to characterize the conduction system in the postinfarct left ventricle (LV). High-density mapping (PentaRay, CARTO) was performed during normal rhythm in patients undergoing ventricular tachycardia ablation. Ripple maps were viewed from the end of the P wave to QRS onset in 1-ms increments. Clusters of >3 ripple bars were interrogated for the presence of Purkinje potentials, which were tagged on the 3D geometry. Repeating this process allowed conduction system delineation. Maps were reviewed in 24 patients (mean 3112 ± 613 points). There were 150.9 ± 24.5 Purkinje potentials per map, at the left posterior fascicle (LPF) in 22 patients (92%) and at the left anterior fascicle (LAF) in 15 patients (63%). The LAF was shorter (41.4 vs 68.8 mm; P =.0005) and activated for a shorter duration (40.6 vs 64.9 ms; P =.002) than the LPF. Fourteen of 24 patients had left bundle branch block (LBBB), with 11 of 14 (78%) having Purkinje potential–associated breakout. There were fewer breakouts from the conduction system during LBBB (1.8 vs 3.4; 1.6 ± 0.6; P =.039) and an inverse correlation between breakout sites and QRS duration (P =.0035). We applied ripple mapping to present a detailed electroanatomic characterization of the conduction system in the postinfarct LV. Patients with broader QRS had fewer LV breakout sites from the conduction system. However, there was 3D mapping evidence of LV breakout from an intact conduction system in the majority of patients with LBBB. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Cardiac pacing from right ventricular (RV) sites may cause electromechanical ventricular dyssynchrony. Invasive and noninvasive mapping studies showed left ventricular (LV) activation sequence in adults. Aim of this study was to seek out the LV endocardial activation (LVEA) in pediatric patients who underwent RV pacing. Methods: Single‐center, prospective study conducted on pediatric patients who underwent left sided catheter ablation of accessory pathways with the Carto Univu mapping system. After successful ablation procedures, LVEA was recorded by the ablation catheter during sinus rhythm (SR) and during para‐hisian (PHP), midseptum (MSP), and apical (RVAP) pacing. Results: Seventeen patients, 13 males, aged 12 (10–15) years, registered LV activation maps and times (LVAT). SR showed significantly shorter LVAT than during pacing. LVAT of PHP was shorter than MSP, while there were not significant differences among PHP and MSP versus RVAP. In SR initial LV endocardial activation occurred in two midseptum sites, inferior‐posterior and superior‐anterior. During PHP, initial activation occurred at parahisian basal septum, rapidly followed by midseptum as in SR. During MSP and RVAP initial activation occurred at midseptum and apex, respectively. From all initial sites, the excitation spreads toward the base of the lateral LV free wall. A mild linear correlation was found between QRS duration and LVAT for MSP and for PHP. Conclusions: In pediatric patients LVEA maps during RV pacing showed that the shortest LVAT was obtained with PHP. The LV activation pattern seemed similar in sinus rhythm, PHP and MSP, from midseptum to LV lateral base. [ABSTRACT FROM AUTHOR]

Transcatheter radiofrequency ablation has been widely introduced for the treatment of tachyarrhythmias. The demand for catheter ablation continues to grow rapidly as the level of recommendation for catheter ablation. Traditional catheter ablation is performed under the guidance of X‐rays. X‐rays can help display the heart contour and catheter position, but the radiobiological effects caused by ionizing radiation and the occupational injuries worn caused by medical staff wearing heavy protective equipment cannot be ignored. Three‐dimensional mapping system and intracardiac echocardiography can provide detailed anatomical and electrical information during cardiac electrophysiological study and ablation procedure, and can also greatly reduce or avoid the use of X‐rays. In recent years, fluoroless catheter ablation technique has been well demonstrated for most arrhythmic diseases. Several centers have reported performing procedures in a purposefully designed fluoroless electrophysiology catheterization laboratory (EP Lab) without fixed digital subtraction angiography equipment. In view of the lack of relevant standardized configurations and operating procedures, this expert task force has written this consensus statement in combination with relevant research and experience from China and abroad, with the aim of providing guidance for hospitals (institutions) and physicians intending to build a fluoroless cardiac EP Lab, implement relevant technologies, promote the standardized construction of the fluoroless cardiac EP Lab. [ABSTRACT FROM AUTHOR]

Background: Catheter ablation (CA) remains challenging due to suboptimal success rates in persistent atrial fibrillation (AF). Existing mapping technologies cannot reliably distinguish sources in this patient population. Recently, the novel electrographic flow (EGF) mapping system was developed using a modified Horn‐Schunk optical flow algorithm to detect and quantify patterns of electrical wavefront propagation in the atria. Objectives: To test the hypothesis that targeted source ablation based on EGF mapping is superior to empiric AF ablation. Methods: We included all consecutive patients undergoing EGF guided ablation for persistent AF. All patients underwent pulmonary vein isolation (PVI) and were treated with the same EAM system (CARTO). The outcome of PVI+EGF guided CA was compared with data of PVI‐only procedures (PVI‐only group) and PVI plus additional empiric adjunctive linear and substrate ablations (PVI+LINES group). 12‐months outcome as freedom from AF and atrial tachycardia/flutter (AT/AFL), procedural safety and efficiency characterized by procedure duration, fluoroscopy use, radiofrequency applications and duration, were analyzed. Both intention‐to‐treat and per protocol analysis were conducted. Results: A total number of 70 patients (39 in PVI+EGF, 16 in PVI‐only and 15 patients in PVI+LINES group) were enrolled. Intention‐to‐treat analysis showed fewer AF recurrences in PVI+EGF as compared with the PVI‐only or PVI+LINES groups at 12 months (25.6% vs. 62.5% vs. 53.3%, p =.02). There were no differences in AT/AFL recurrence (17.9% vs. 37.5% vs. 20.0%, p =.37). Procedure times were longer in PVI+EGF group (p <.01), and there were no differences in fluoroscopy use (p =.67). Conclusion: Our data suggest that patients treated with EGF‐guided CA developed fewer AF recurrences. Although the procedure times are longer, it seems to be safe and offers a more targeted, patient‐specific ablation strategy beyond PVI than adjunctive empiric lines and substrate ablation in this complex group of patients. [ABSTRACT FROM AUTHOR]

Abstract Background A three‐dimensional (3D) mapping system is essential to reduce radiation exposure during catheter ablation. When using the CARTO 3D mapping system, only the catheter with magnetic sensor can visualize its location. However, once target chamber matrix is created using the catheter, even the catheters without magnetic sensors (CWMS) can enable visualization. We aimed to investigate the feasibility and safety of placing a CWMS in the coronary sinus (CS) without fluoroscopic guidance. Methods The study group comprised 88 consecutive patients who underwent catheter ablation. CWMS placement was performed without fluoroscopic guidance in 47 patients and with fluoroscopic guidance in 41 patients. Placement without fluoroscopic guidance was performed after creating a visualization matrix of the CS, right atrium, and superior vena cava using a catheter with a magnetic sensor. Feasibility and safety were compared between the two groups. Results Successful catheter placement was achieved in all patients without fluoroscopic guidance, with no inter‐group difference in the median procedure time: with guidance, 120.0 [96.0–135.0] min, and without guidance, 110.0 [97.5–125.0] min; p = .22. However, radiation exposure was significantly shorter, and the effective dose was lower without fluoroscopic guidance (0 [0–17.5] s and 0 [0–0.004] mSv, respectively) than with fluoroscopic guidance (420.0 [270.0–644.0] s and 0.73 mSv [0.36–1.26], respectively); both p

A technique of two-stage three-dimensional mapping of the optical breakdown threshold in diamond crystals is proposed. In the first stage diamond is irradiated by high-energy ultrashort laser pulses, which initiate multiple microbreakdowns in the probed volume of material; these breakdowns cause formation of graphite microinclusions. A sharp decrease in the spatial density of microinclusions in some crystal zone indicates a significant increase in the average value of breakdown threshold in this zone as compared with the neighborhood. The second stage of mapping implies measurement of the absolute values of breakdown threshold by choosing the minimum laser pulse energy necessary for the formation of a graphite microinclusion at a point studied. The "abnormal" crystal zones revealed in the first stage are investigated especially thoroughly, with optimal spatial resolution. Application of this technique to synthetic diamond single crystals from different manufacturers, grown by chemical vapor deposition (CVD), revealed zones in these crystals where the breakdown threshold changes by a factor of more than 10. The boundaries of these zones are located parallel to the (100) growth face; the layer thickness and position vary unpredictably. [ABSTRACT FROM AUTHOR]

Three-dimensional mapping is an essential component of autonomous Micro Aerial Vehicle (MAV) navigation. The paper focuses on the 3D spatial representation method of MAV to overcome the collision problem caused by soft constraints, control error, and planning with the center of mass by inflating the occupancy grid map. A fast incremental inflated map construction method is proposed, which reduces the time-consumption caused by the increase of map range and inflated size. The method focuses on areas of the map that occupied state changes and introduces two arrays that record newly appearing and disappearing obstacles. Then, a series of breadth-first search algorithms are used to traverse the parts of the inflated map that need local modification to update the inflated map. Moreover, a sliding map model is designed based on the MAV position, which is suitable for large-range autonomous flight. The effectiveness of the proposed approach is verified with simulated and actual flight data. The proposed method takes about 3 ms to construct the inflated map with a local update range of 16 m × 16 m × 6 m. [ABSTRACT FROM AUTHOR]

Objective: Few studies have been conducted to establish animal models of left bundle branch block by using three-dimensional mapping systems. This research was aimed at creating a canine left bundle branch block model by using a three-dimensional mapping system. Materials and Methods: We used a three-dimensional mapping system to map and ablate the left bundle branch in beagles. Results: Ten canines underwent radiofrequency ablation, among which left bundle branch block was successfully established in eight, one experienced ventricular fibrillation, and one developed third-degree atrioventricular block. The maximum HV interval measured within the left ventricle was 29.00 ± 2.93 ms, and the LBP-V interval at the ablation site was 20.63 ± 2.77 ms. The LBP-V interval at the ablation target was 71.08% of the maximum HV interval. Conclusion: This three-dimensional mapping system is a reliable and effective guide for ablation of the left bundle branch in dogs. [ABSTRACT FROM AUTHOR]

Ectopic potentials in the SVC can act not only as a trigger but also as a driver of AF. These potentials may be refractory to conventional pulmonary vein isolation for AF. In the present case, the atrium resumed a sinus rhythm spontaneously on the completion of SVC isolation and AF could no longer be induced. However, there was residual fibrillatory activity in the SVC. These findings suggest that residual activity in the SVC worked as a driver of AF. SVC reconnection is commonly reported, with a prevalence of 70%. Thus, we decided to eliminate residual fibrillatory activity in the SVC to prevent recurrence of AF after the third catheter ablation session. In the presence of a fibrillatory pattern, conventional activation mapping techniques cannot map residual SVC activity; however, ICL mapping using the CARTO system can identify the target site of ablation in the isolated SVC. [ABSTRACT FROM AUTHOR]

Background: A three‐dimensional (3D) mapping system is essential to reduce radiation exposure during catheter ablation. When using the CARTO 3D mapping system, only the catheter with magnetic sensor can visualize its location. However, once target chamber matrix is created using the catheter, even the catheters without magnetic sensors (CWMS) can enable visualization. We aimed to investigate the feasibility and safety of placing a CWMS in the coronary sinus (CS) without fluoroscopic guidance. Methods: The study group comprised 88 consecutive patients who underwent catheter ablation. CWMS placement was performed without fluoroscopic guidance in 47 patients and with fluoroscopic guidance in 41 patients. Placement without fluoroscopic guidance was performed after creating a visualization matrix of the CS, right atrium, and superior vena cava using a catheter with a magnetic sensor. Feasibility and safety were compared between the two groups. Results: Successful catheter placement was achieved in all patients without fluoroscopic guidance, with no inter‐group difference in the median procedure time: with guidance, 120.0 [96.0–135.0] min, and without guidance, 110.0 [97.5–125.0] min; p =.22. However, radiation exposure was significantly shorter, and the effective dose was lower without fluoroscopic guidance (0 [0–17.5] s and 0 [0–0.004] mSv, respectively) than with fluoroscopic guidance (420.0 [270.0–644.0] s and 0.73 mSv [0.36–1.26], respectively); both p <.001. Conclusions: CWMS placement without fluoroscopic guidance is feasible, safe to perform, and does not involve complications. Our technique provides an option to decrease radiation exposure during catheter ablation and electrophysiological testing. [ABSTRACT FROM AUTHOR]

A three-dimensional (3D) mapping system is safe and effective for catheter ablation of incisional atrial tachycardia (IAT). Prolongation of the PR interval is occasionally observed after this procedure. Although a first-degree atrioventricular block is typically benign, an excessively prolonged PR interval can indicate a worse prognosis. Currently, a method to predict the PR interval after ablation therapy for IAT is lacking. We report the case of a 70-year-old woman with paroxysmal atrial tachycardia, in which our maneuver using a 3D mapping system and the electrophysiological findings enabled us to preoperatively predict the post-ablation PR interval. We believe that this method is useful for determining treatment strategies for IAT. Three-dimensional (3D) mapping systems can clearly visualize macro-reentrant circuits and enable the creation of precise ablation lines. When creating ablation lines for incisional atrial tachycardia, attention should be paid to the prolongation of the PR interval, because an excessively prolonged PR interval may indicate a worse prognosis. Herein, we have presented a method for predicting the post-ablation PR interval using a 3D mapping system and electrophysiological findings. [ABSTRACT FROM AUTHOR]

• TCP/IP-based closed-loop system enables immersive VR control of machinery. • Remote operation framework enhances agricultural safety and productivity. • The VR system provides 3D spatial information suitable for remote control. • Enhanced SfM integrates OpenMVG and LoFTR to improve mapping accuracy. In agricultural settings, the unstructured nature of certain production environments, along with the high complexity and inherent risks of production tasks, poses significant challenges to achieving full automation and effective on-site machine control. Remote control technology, which leverages human intelligence and precise machine movements, ensures operator safety and boosts productivity. Recently, virtual reality (VR) has shown promise in remote control applications by overcoming single-view limitations and providing three-dimensional information, yet most studies have not focused on agricultural settings. Therefore, to bridge the gap, this study proposes a large-scale digital mapping and immersive human–machine teleoperation framework specifically designed for precision agriculture. In this research, a DJI unmanned aerial vehicle (UAV) was utilized for data collection, and a novel video segmentation approach based on feature points was introduced. To accommodate the variability of complex textures, this method proposes an enhanced Structure from Motion (SfM) approach. It integrates the open Multiple View Geometry (OpenMVG) framework with Local Features from Transformers (LoFTR). The enhanced SfM produces a point cloud map, which is further processed through Multi-View Stereo (MVS) to generate a complete map model. For control, a closed-loop system utilizing TCP/IP for VR control and positioning of agricultural machinery was introduced. This system offers a fully visual-based method for immersive control, allowing operators to utilize VR technology for remote operations. The experimental results demonstrate that the digital map reconstruction algorithm developed in this study offers superior detail reconstruction, along with enhanced robustness and convenience. The user-friendly remote control method also showcases its advantages over traditional video streaming-based remote operations, providing operators with a more comprehensive and immersive experience and a higher level of situational awareness. [ABSTRACT FROM AUTHOR]

Abstract Background Denis and Ferguson et al.’s three-column spinal theory has been widely accepted and applied. However, this three-column theory was proposed based solely on observation and experience without thorough documented data and analysis. The aim of this study was to analyze and improve Denis and Ferguson et al.’s three-column spinal theory to propose a novel three-column concept in epidemiology, morphology and biomechanics. Methods A retrospective analysis of the computed tomography imaging data of patients with a diagnosis of T11-L5 vertebral fractures was conducted between February 2010 and December 2018. Three-dimensional (3D) distribution maps of fracture lines of all subjects were obtained based on 3D mapping techniques. In addition, a 25-year-old health male volunteer was recruited for the vertebral finite element force analysis. Results The present study enrolled 459 patients (age: 48 ± 11.42 years), containing a total of 521 fractured vertebrae. The fracture lines peaked in the upper and the outer third sections of the vertebra, starting from the anterior part of the vertebral pedicles in 3-D maps. Regarding flexion and extension of the spine, the last third of the vertebral body in front of the spinal canal was one main stress center in the finite element analysis. The stress on the vertebral body was greater in front of the pedicles in the lateral bending. Conclusion The study reveals that the posterior one-third of the vertebral body in front of the spinal canal and the posterior one-third of the vertebral body in front of the pedicle are very different in terms of fracture characteristics and risks to spinal canal (3D maps and stress distributing graphs), therefore, they should be classified as different columns. We provide strong evidence that Su’s three-column theory complies with the characteristics of vertebral physiological structure, vertebral fracture, and vertebral biomechanics. Graphical abstract

Laboratory diffraction contrast tomography (LabDCT) is a recently developed technique to map crystallographic orientations of polycrystalline samples in three dimensions non‐destructively using a laboratory X‐ray source. In this work, a new theoretical procedure, named LabXRS, expanding LabDCT to include mapping of the deviatoric strain tensors on the grain scale, is proposed and validated using simulated data. For the validation, the geometries investigated include a typical near‐field LabDCT setup utilizing Laue focusing with equal source‐to‐sample and sample‐to‐detector distances of 14 mm, a magnified setup where the sample‐to‐detector distance is increased to 200 mm, a far‐field Laue focusing setup where the source‐to‐sample distance is also increased to 200 mm, and a near‐field setup with a source‐to‐sample distance of 200 mm. The strain resolution is found to be in the range of 1–5 × 10−4, depending on the geometry of the experiment. The effects of other experimental parameters, including pixel binning, number of projections and imaging noise, as well as microstructural parameters, including grain position, grain size and grain orientation, on the strain resolution are examined. The dependencies of these parameters, as well as the implications for practical experiments, are discussed. [ABSTRACT FROM AUTHOR]

Background: Conduction channels have been demonstrated within the postinfarct scar and seem to be co-located with the isthmus of ventricular tachycardia (VT). Mapping the local scar potentials (SPs) that define the conduction channels is often hindered by large far-field electrograms generated by healthy myocardium.Objective: The purpose of this study was to map conduction channel using ripple mapping to categorize SPs temporally and anatomically. We tested the hypothesis that ablation of early SPs would eliminate the latest SPs without direct ablation.Methods: Ripple maps of postinfarct scar were collected using the PentaRay (Biosense Webster) during normal rhythm. Maps were reviewed in reverse, and clusters of SPs were color-coded on the geometry, by timing, into early, intermediate, late, and terminal. Ablation was delivered sequentially from clusters of early SPs, checking for loss of terminal SPs as the endpoint.Results: The protocol was performed in 11 patients. Mean mapping time was 65 ± 23 minutes, and a mean 3050 ± 1839 points was collected. SP timing ranged from 98.1 ± 60.5 ms to 214.8 ± 89.8 ms post QRS peak. Earliest SPs were present at the border, occupying 16.4% of scar, whereas latest SPs occupied 4.8% at the opposing border or core. Analysis took 15 ± 10 minutes to locate channels and identify ablation targets. It was possible to eliminate latest SPs in all patients without direct ablation (mean ablation time 16.3 ± 11.1 minutes). No VT recurrence was recorded (mean follow-up 10.1 ± 7.4 months).Conclusion: Conduction channels can be located using ripple mapping to analyze SPs. Ablation at channel entrances can eliminate the latest SPs and is associated with good medium-term results. [ABSTRACT FROM AUTHOR]

Abstract A 17‐year‐old woman presented with frequent palpitations and shortness of breath and was diagnosed with drug‐refractory ventricular parasystole. We predicted that the parasystole originated from the left anterior fascicle (LAF). Detailed activation maps of both conduction systems, including the LAF, during sinus rhythm and ventricular parasystole were obtained using a parallel mapping system. We confirmed the earliest fascicular potential of the parasystole and performed catheter ablation with no complications. This novel mapping algorithm for simultaneous acquisition of multiple maps aided effective treatment of ventricular parasystole originating from the LAF.

Objectives: To evaluate the feasibility, safety, and clinical efficacy of non-fluoroscopic radiofrequency catheter ablation of atrial fibrillation (AF) in comparison to traditional fluoroscopy-guided ablation in a local Canadian community cohort. Methods: We retrospectively studied consecutive patients with paroxysmal and persistent AF undergoing pulmonary vein isolation (PVI) guided by intracardiac echocardiography (ICE) and Carto system (CartoSound module). ICE-guided PVI without fluoroscopy (Zero-fluoro group) was performed in 116 patients, and conventional fluoroscopy-guided PVI (Traditional group) was performed in 131 patients. Results: Two hundred and forty-seven patients with AF (60.7% male; mean age: 62.2 ± 10.6 years; paroxysmal AF =63.1%) who underwent PVI were studied. Mean procedure times were similar between both groups (136.8±33.4 minutes in the zero-fluoro group vs. 144.3±44.9 minutes in the traditional group; p=0.2). Acute PVI was achieved in all patients. Survival from early AF recurrence was 85% and 81% in the zero-fluoro and traditional groups, respectively (p = 0.06). Survival from late AF recurrence (12-months) between the zero-fluoro and traditional groups was also similar (p=0.1). Moreover, there were no significant differences between complication rates, including hematoma (p = 0.2) and tamponade (p = 1), between both groups. Conclusions: Zero-fluoroscopy ICE and CartoSound-guided AF ablation may be safe and feasible in patients undergoing PVI compared to conventional fluoroscopy-guided ablation. [ABSTRACT FROM AUTHOR]

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An editorial is presented on Potential advantages of the KODEX‐EPD system as the fourth 3D mapping system for atrial fibrillation ablation. Topics include cardiac arrest in a randomized fashion could not definitely reveal the advantage of catheter ablation compared with medical therapy among patients with AF; and distinct dielectric properties of biological tissue by measuring voltages between body surface sensors and the catheters.

Copyright of Herzschrittmachertherapie und Elektrophysiologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Atrioventricular node (AVN) ablation combined with His bundle pacing is an effective strategy for permanent atrial fibrillation (AF) with rapid ventricular rate refractory to pharmacological therapy. We aimed to access the feasibility and efficiency of His bundle pacing and AVN ablation guided by three‐dimensional (3‐D) mapping system throughout the procedure. Methods: Eighteen patients with permanent AF with refractory rate and symptoms were referred for His bundle pacing and AVN ablation guided by 3‐D mapping (CARTO3). Electroanatomic 3‐D mapping of the right atrium and right ventricle was performed by the ablation catheter with CARTO 3 system, followed by the visualization of the leads for implantation and AVN ablation. Results: Implantation of His bundle and ventricular leads and AVN ablation were achieved successfully with the help of 3‐D mapping in 17 patients. Selective His bundle pacing was achieved in five patients (29.4%), and the other (70.6%) were nonselective His bundle pacing. The mean procedure duration was 99.4 ± 16.4 minutes. The mean fluoroscopy time was 7.0 ± 2.6 minutes. The time spent on His lead implantation was 6.1 ± 3.2 minutes. One patient experienced AVN ablation from left side under aortic valves due to no effect of ablation in right atrium. Conclusion: His bundle pacing and AVN ablation guided by throughout real‐time 3‐D mapping system are of high‐efficiency and feasibility. [ABSTRACT FROM AUTHOR]

Background: Denis and Ferguson et al.'s three-column spinal theory has been widely accepted and applied. However, this three-column theory was proposed based solely on observation and experience without thorough documented data and analysis. The aim of this study was to analyze and improve Denis and Ferguson et al.'s three-column spinal theory to propose a novel three-column concept in epidemiology, morphology and biomechanics.Methods: A retrospective analysis of the computed tomography imaging data of patients with a diagnosis of T11-L5 vertebral fractures was conducted between February 2010 and December 2018. Three-dimensional (3D) distribution maps of fracture lines of all subjects were obtained based on 3D mapping techniques. In addition, a 25-year-old health male volunteer was recruited for the vertebral finite element force analysis.Results: The present study enrolled 459 patients (age: 48 ± 11.42 years), containing a total of 521 fractured vertebrae. The fracture lines peaked in the upper and the outer third sections of the vertebra, starting from the anterior part of the vertebral pedicles in 3-D maps. Regarding flexion and extension of the spine, the last third of the vertebral body in front of the spinal canal was one main stress center in the finite element analysis. The stress on the vertebral body was greater in front of the pedicles in the lateral bending.Conclusion: The study reveals that the posterior one-third of the vertebral body in front of the spinal canal and the posterior one-third of the vertebral body in front of the pedicle are very different in terms of fracture characteristics and risks to spinal canal (3D maps and stress distributing graphs), therefore, they should be classified as different columns. We provide strong evidence that Su's three-column theory complies with the characteristics of vertebral physiological structure, vertebral fracture, and vertebral biomechanics. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the role of ultrahigh‐density mapping for conduction isthmus (CI) characterization in adult congenital heart disease (ACHD). Background: Catheter ablation remains suboptimal for ACHD with atypical intra‐atrial reentrant tachycardias (IART) that can be challenging to define using existing mapping technology. Methods: An ultrahigh‐density mapping system was selectively employed over a 1‐year period for procedures involving noncavotricuspid isthmus‐dependent‐IART. A global activation histogram (GAH) was assessed for the ability to predict ablation targets. Procedural characteristics were compared to a group of matched controls. Results: Twenty patients (mean age 43 ± 15, 70% male) underwent 20 procedures targeting 34 tachycardias during the study period. Diagnoses included single ventricle (8), tetralogy of Fallot (2), left heart obstruction (3), Ebstein's anomaly (2) atrial septal defect (2), Mustard operation (2), and Rasteilli operation (1). Prior catheter ablation/Maze operation had been performed in 12 (60%). The median time per map was 21 minutes (interquartile range [IQR], 16‐32), representing 14 834 points per map (IQR 9499‐43 191; P < .001 vs controls). Review of GAH maps showed lower trough values were associated with more favorable IART CI characteristics (P ≤ =.001 for all). Acute success was achieved in 19/20 (95%) procedures, with tachycardia termination during the first lesion in eight cases (P = .02 vs controls). There was one recurrence during 0.6 years follow‐up. Conclusions: Ultrahigh‐density mapping supplemented with the GAH tool was effective for CI identification in a cohort of complex ACHD patients. Catheter ablation was more efficient compared to controls, suggesting precise CI characterization using this technology. [ABSTRACT FROM AUTHOR]

With almost limitless applications across marine and freshwater environments, the number of people using, and wanting to use, remotely piloted aircraft systems (or drones) is increasing exponentially. However, successfully using drones for data collection and mapping is often preceded by hours of researching drone capabilities and functionality followed by numerous limited-success flights as users tailor their approach to data collection through trial and error. Working over water can be particularly complex and the published research using drones rarely documents the methodology and practical information in sufficient detail to allow others, with little remote pilot experience, to replicate them or to learn from their mistakes. This can be frustrating and expensive, particularly when working in remote locations where the window of access is small. The aim of this paper is to provide a practical guide to drone-based data acquisition considerations. We hope to minimise the amount of trial and error required to obtain high-quality, map-ready data by outlining the principles and practice of data collection using drones, particularly in marine and freshwater environments. Importantly, our recommendations are grounded in remote sensing and photogrammetry theory so that the data collected are appropriate for making measurements and conducting quantitative data analysis. With almost limitless applications across marine and freshwater environments, the number of people using, and wanting to use, drones is rapidly increasing. However, what appears simple at first glance can often become complicated when quantitative data collection is required. In this paper we provide a practical guide to drone-based data acquisition considerations, particularly in marine and freshwater environments. [ABSTRACT FROM AUTHOR]

A 17‐year‐old woman presented with frequent palpitations and shortness of breath and was diagnosed with drug‐refractory ventricular parasystole. We predicted that the parasystole originated from the left anterior fascicle (LAF). Detailed activation maps of both conduction systems, including the LAF, during sinus rhythm and ventricular parasystole were obtained using a parallel mapping system. We confirmed the earliest fascicular potential of the parasystole and performed catheter ablation with no complications. This novel mapping algorithm for simultaneous acquisition of multiple maps aided effective treatment of ventricular parasystole originating from the LAF. [ABSTRACT FROM AUTHOR]

Background: A new three‐dimensional heart anatomical simulator (3D HAS) has been created combining a physical heart model with an electroanatomic mapping (EAM) system. The aim of this study is to describe the development and the validation process of this device. Methods: We developed the 3D HAS combining a physical heart model with an EAM system. This simulator was then validated by 10 electrophysiologists, subdivided in two groups based on their experience in electrophysiology procedures. The performance of the experts was compared to the one of the novices in achieving three different tasks: fluoroless reconstruction of the right atrium, coronary sinus cannulation, and deployment of a linear ablation lesion in the cavotricuspid isthmus. For each operator, a score was calculated based on objective parameter for each task and for the overall performance. Results: The 3D HAS was located in an environment that allowed use of the main features of the EAM system including contact force sensing. No technical issue was encountered during the validation process. The experts' performance was significantly better than the one of the novices both overall (P = 0.009) and in each task (right atrium reconstruction, P = 0.016; coronary sinus cannulation, P = 0.008; ablation lesion, P = 0.03). Conclusions: The 3D HAS is reliable and allows use of the main features of an EAM system in the right atrium. The ability to discriminate different levels of experience suggests that this simulator is enough realistic and could be useful for electrophysiology training. [ABSTRACT FROM AUTHOR]

The present paper sheds light on the interfacial structural transformation taking place upon epitaxial growth of ferromagnetic 3d metal compounds – Co, Ni and CoFeB – on the surface of magnetically ordered iron oxides – Fe3O4, Fe2O3 and Y3Fe5O12. The reducing conditions due to the excess of neutral metal atoms at the surface cause reduction of the Fe3+ ions of the underlying iron oxide layer to the Fe2+ state and subsequent recrystallization of the subsurface region to an MeO‐like rock salt crystal structure. The corresponding change of the lattice symmetry can be readily recognized by in situ high‐energy electron diffraction reciprocal‐space mapping and ex situ X‐ray diffraction techniques. From an analysis of diffraction and X‐ray absorption data a tentative model of the structural transformation is proposed, based on penetration of Me atoms into the near‐surface region of the iron oxide lattice. Once a few nanometre thick oxidized layer is formed, further growth of pure metallic film with native crystal structure takes place. An important observation made is that the oxidation/reduction effects do not occur when 3d metals are deposited onto more stable MgO and Gd3Ga5O12 surfaces. This circumstance makes it appropriate to propose these materials for use as buffer layers to prevent formation of antiferromagnetic monoxide transition regions in multilayered magnetic structures. The presented results are supposed valuable for development of hybrid ferromagnetic heterostructures attractive for various spintronic applications. [ABSTRACT FROM AUTHOR]

We report the use of the Abbott three-dimensional mapping system (EnSite Precision) for the placement of an atrial pacemaker lead in a patient after modified Fontan procedure. The mapping system was used for the identification of a promising pacing site in the complexly modified right atrium and to visualize the successful placement of an atrial lead at the same spot.

Most cultivated upland areas of northeast Thailand are characterized by sandy and infertile soils, which are difficult to improve agriculturally. Information about the clay (%) and cation exchange capacity (CEC—cmol(+)/kg) are required. Because it is expensive to analyse these soil properties, electromagnetic (EM) induction instruments are increasingly being used. This is because the measured apparent soil electrical conductivity (ECa—mS/m), can often be correlated directly with measured topsoil (0−0.3 m), subsurface (0.3−0.6 m) and subsoil (0.6−0.9 m) clay and CEC. In this study, we explore the potential to use this approach and considering a linear regression (LR) between EM38 acquired ECa in horizontal (ECah) and vertical (ECav) modes of operation and the soil properties at each of these depths. We compare this approach with a universal LR relationship developed between calculated true electrical conductivity (σ—mS/m) and laboratory measured clay and CEC at various depths. We estimate σ by inverting ECah and ECav data, using a quasi-3D inversion algorithm (EM4Soil). The best LR between ECa and soil properties was between ECah and subsoil clay (R2 = 0.43) and subsoil CEC (R2 = 0.56). We concluded these LR were unsatisfactory to predict clay or CEC at any of the three depths, however. In comparison, we found that a universal LR could be established between σ with clay (R2 = 0.65) and CEC (R2 = 0.68). The LR model validation was tested using a leave-one-out-cross-validation. The results indicated that the universal LR between σ and clay at any depth was precise (RMSE = 2.17), unbiased (ME = 0.27) with good concordance (Lin’s = 0.78). Similarly, satisfactory results were obtained by the LR between σ and CEC (Lin’s = 0.80). We conclude that in a field where a direct LR relationship between clay or CEC and ECa cannot be established, can still potentially be mapped by developing a LR between estimates of σ with clay or CEC if they all vary with depth.

Background: Catheter ablation of right-sided accessory pathways (APs) has lower success and higher recurrence rates compared to left-sided substrates. Irrigated-tip catheter (ITC) ablation might offer an advantage in this setting but data about its use in patients below 18 years are scarce. The aim of this study was to compare an ITC approach to conventional catheter ablation. Methods: A retrospective analysis of all patients <18 years undergoing radiofrequency ablation (RFA) for right-sided APs from 2004 to 2014 at our institution was performed. Patients either underwent an ITC approach in combination with 3-D mapping (Group 1; n = 53) or a conventional non-ITC approach (Group 2; n = 52). Study endpoints were acute procedural success, safety, and recurrence rate. A total of 105 mostly adolescent patients (56.2% male;median age 14 years) with 107 right-sided APs were included. Results: The prevailing anatomic AP locations were right posteroseptal (44.9%), right anterior/anterolateral (24.3%), and right lateral (13.1%). Acute success (94.3% vs 94.2%) did not differ between the groups. One major complication (pericardial effusion) occurred in the non-ITC group. Overall, freedom from AP recurrence was 94% at 4 years in the ITC group, and 81% at 4 years in the non-ITC group (P = 0.04). Conclusions: The use of ITCs in combination with 3-D mapping system for ablation of rightsided APs in adolescents has a high acute success rate, is safe, and associated with a significantly reduced recurrence rate compared to a non-ITC/conventional approach. It might be considered as alternative approach in this age group. [ABSTRACT FROM AUTHOR]