Three-dimensional System Research Articles

Percutaneous endocardial septal radiofrequency ablation on syncope in patients with hypertrophic obstructive cardiomyopathy: a short-term safety and efficacy study.

Syncope is a serious consequence in patients with hypertrophic obstructive cardiomyopathy (HOCM). Percutaneous endocardial septal radiofrequency ablation (PESA) has emerged as a promising intervention to alleviate symptoms and enhance the quality of life for HOCM patients. However, little is known about the effects of PESA on syncope in HOCM. The authors aimed to study the effects of PESA on syncope in patients with HOCM. Nineteen patients with HOCM and syncope were enrolled. The left ventricular outflow tract gradient (LVOTG) of the patients was more than 50mmHg despite medication. The participants underwent PESA under the guidance of intracardiac echocardiography (ICE) combined with a three-dimensional electrophysiological mapping system. The patients were followed for 3 (3-5.5) months. The mean age of the patients was 54.8±13.7 years. Out of the 19 participants, 7 (37%) were females. During the follow-up, the syncope was completely alleviated in 14 patients (73.7%) or the syncope episodes were reduced greater than or equal to 80% in 16 patients (84.2%). The mean NYHA functional class significantly improved from 2.2±0.7 at baseline to 1.7±0.6 during follow-up (P=0.002). The LVOTG and septal thickness showed a decreasing trend from baseline to follow-up (LVOTG: P=0.083, septal thickness: P=0.086). The authors' investigation provides evidence supporting the effectiveness of PESA in reducing syncope episodes in patients with HOCM.

Existence of long-range magnetic order in Heisenberg spin nanoribbons with edge modification

Long-range magnetic order appears on a side decorated Heisenberg spin nanoribbon at nonzero temperature, although no spontaneous magnetization exists in a one- or two-dimensional isotropic Heisenberg model at any nonzero temperature according to the Mermin–Wagner theorem. By use of the spin Green’s function method, we calculated the magnetizations of Heisenberg nanoribbons decorated by side spins with single-ion anisotropy and found that the system exhibits a nonzero transition temperature, whether the decorated edge spins of the system link together or separate from each other. When the width of the nanoribbon achieves infinite limit, the transition temperatures of the system tend to the same finite constant eventually whether one edge or both edges are decorated by side spins in the nanoribbon. The results reveal that the magnetism of a low-dimensional spin system is different from that of a three-dimensional spin system. When the single-ion anisotropy of edge spins in a Heisenberg spin nanoribbon can be modulated by an electric field experimentally, various useful long-range magnetic orders of the system can be obtained. This work can provide a detailed theoretical basis for designing and fabricating next-generation low-dimensional magnetic random-access memory.

Initial real-world data on catheter ablation in patients with persistent atrial fibrillation using the novel lattice-tip focal pulsed-field ablation catheter.

Technological advancements have contributed to the enhanced precision and lesion flexibility in pulsed-field ablation (PFA) by integrating a three-dimensional mapping system combined with a point-by-point ablation strategy. Data regarding the feasibility of this technology remain limited to some clinical trials. This study aims to elucidate initial real-world data on catheter ablation utilizing a lattice-tip focal PFA/radiofrequency ablation (RFA) catheter in patients with persistent atrial fibrillation (AF). Consecutive patients who underwent catheter ablation for persistent AF via the lattice-tip PFA/RFA catheter were enrolled. We evaluated acute procedural data including periprocedural data as well as the clinical follow-up within a 90-day blanking period. In total, 28 patients with persistent AF underwent AF ablation either under general anaesthesia (n = 6) or deep sedation (n = 22). In all patients, pulmonary vein isolation was successfully achieved. Additional linear ablations were conducted in 21 patients (78%) with a combination of successful anterior line (n = 13, 46%) and roof line (n = 19, 68%). The median procedural and fluoroscopic times were 97 (interquartile range, IQR: 80-114) min and 8.5 (IQR: 7.2-9.5) min, respectively. A total of 27 patients (96%) were interviewed during the follow-up within the blanking period, and early recurrent AF was documented in four patients (15%) including one case of recurrent AF during the hospital stay. Neither major nor minor procedural complication occurred. In terms of real-world data, our data confirmed AF ablation feasibility utilizing the lattice-tip focal PFA/RFA catheter in patients with persistent AF.

Accuracy of Smartphone-Based Three-Dimensional Facial Scanning System: A Systematic Review.

Recently, the integration of 3D face scanning into smartphones has raised vast interest in plastic surgery. With the release of smartphones featuring 3D face scanning technology, users now can capture detailed 3D models of their faces using their smartphones. However, trueness and precision of this system is less well established. PubMed, Cochrane Library, Embase, ScienceDirect, Scopus, and Web of Science databases were searched for studies evaluating 3D scanning of smartphone devices and conventional 3D imaging systems from January 1, 2017, to June 1, 2023. A qualitative systematic review was conducted by two review authors after independently selecting studies, extracting data, and assessing the risk of bias of included studies. A total of 11 studies were included, all focusing on the accuracy of smartphone 3D facial scanning. The results show that although smartphones perform poorly on deep and irregular surfaces, they are accurate enough for clinical applications and have the advantage of being economical and portable. Smartphone-based 3D facial scanning has been basically validated for clinical application, showing broad clinical application prospects in plastic surgery. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The effect of boron anomaly on the dielectric properties and thermal expansion of barium borosilicate glasses for 3D packaging systems

Barium borosilicate (BBS) glass is a potential three-dimensional system packaging and sensor cover material. In this study, we prepared glass samples with different SiO2/B2O3 ratios based on the revised model of Dell and Bray and discussed the effect of boron anomaly on dielectric and thermal properties through Raman spectroscopy. The results indicate that the [BO4] tetrahedrons are beneficial in reducing the dielectric constant and dielectric loss to a certain extent, while the improvement in the coefficient of thermal expansion (CTE) is attributed to the depolymerization of the glass network by the [BO3] triangles. After the disappearance of the boron anomaly, a certain amount of dielectric performance is sacrificed in exchange for an increase in the CTE. When the substitution rate of B2O3 for SiO2 reaches 15.12 mol%, the CTE of the sample increases to 8.43 × 10−6/°C, in addition, the dielectric constant and dielectric loss decrease to 4.90 and 0.0071 (@1 GHz), respectively. In summary, this work provides a suitable method for preparing glass with a high coefficient of expansion and low dielectric loss to address the thermal mismatch effect of different materials in electronic packaging systems.

First experience with a vendor-neutral three-dimensional mapping system for cardiac magnetic resonance-guided electrophysiological procedures: a case report

Abstract Background Fluoroscopy-guided catheter ablation has become the gold standard for treatment of cardiac arrhythmias. High resolution electro-anatomical mapping systems have become fundamental to perform these procedures. Recently, interventional cardiac magnetic resonance (iCMR) has been proposed as an alternative for fluoroscopy to guide atrial flutter ablations. The clinical experience with iCMR and dedicated three-dimensional mapping systems is growing. NorthStar is currently the first available vendor-neutral mapping system. Case summary We performed a real-time CMR-guided cavotricuspid isthmus (CTI) catheter ablation (CA) on a 69-year-old man using a novel mapping system (NorthStar Mapping System, Imricor Medical Systems, MN, USA). Starting from the CMR imaging, a pre-rendered segmentation model was loaded on NorthStar and used to guide the catheters, display voltage and activation maps, show mapping and ablation points. NorthStar can also take full control of the CMR scanner (i.e. start/stop sequences for anatomical information, tissue characterization, and catheter visualization) and communicate with the recorder/stimulator system (Advantage-MR EP, Imricor Medical Systems, MN, USA). With comparable procedural time to standard fluoroscopy-guided CA, CTI bidirectional block was achieved, without any complication. Discussion Using the NorthStar Mapping System, we managed to achieve a successful CMR-guided CTI ablation without any complication. Its further use should be explored, especially in more complex arrhythmias where a substrate-guided ablation is critical, as it could significantly improve results in terms of arrhythmia recurrence.

Construction of a three-dimensional culture system based on Gelatin methacryloyl hydrogel for lung cancer cells

Abstract Hypoxia and acidity are key characteristics of the tumor microenvironment (TME). Gelatin methacryloyl (GelMA) is a versatile biomaterial extensively utilized in various biomedical fields. Studies have shown that during the photocrosslinking process of GelMA hydrogel, the commonly used photoinitiator Irgacure 2959 consumes oxygen and induces an acidic and hypoxia environment. However, there is currently limited research on its involvement in the three-dimensional (3D) culture of tumor cells. Therefore, we constructed a 3D culture system utilizing GelMA hydrogel and investigated its influence on the growth and drug response of lung cancer cells (A549). The results demonstrated that the GelMA hydrogel-based 3D culture system exhibited excellent biocompatibility and robust mechanical properties and provided an acidic microenvironment conducive to tumor cell proliferation. Furthermore, the cancer cells exhibited heightened sensitivity to chemotherapeutics in this 3D culture model. These results suggest that the GelMA hydrogel-based 3D culture system can serve as a perfect model for in vitro study of tumor cells.

Combining three-dimensional acoustic coring and a convolutional neural network to quantify species contributions to benthic ecosystems.

The seafloor is inhabited by a large number of benthic invertebrates, and their importance in mediating carbon mineralization and biogeochemical cycles is recognized. However, the majority of fauna live below the sediment surface, so most means of survey rely on destructive sampling methods that are limited to documenting species presence rather than event driven activity and functionally important aspects of species behaviour. We have developed and tested a laboratory-based three-dimensional acoustic coring system that is capable of non-invasively visualizing the presence and activity of invertebrates within the sediment matrix. Here, we present reconstructed three-dimensional acoustic images of the sediment profile, with strong backscatter revealing the presence and position of individual benthic organisms. These data were used to train a three-dimensional convolutional neural network model and, using a combination of data augmentation and data correction techniques, we were able to identify individual species with an 88% accuracy. Combining three-dimensional acoustic coring with deep learning forms an effective and non-invasive means of providing detailed mechanistic information of in situ species-sediment interactions, opening new opportunities to quantify species-specific contributions to ecosystems.

Construction and application of a three-dimensional vascular variation-based nephrometry scoring system for completely endophytic renal tumors

BackgroundCompletely endophytic renal tumors (CERT) pose significant challenges due to their anatomical complexity and loss of visual clues about tumor location. A facile scoring model based on three-dimensional (3D) reconstructed images will assist in better assessing tumor location and vascular variations. MethodsIn this retrospective study, 80 patients diagnosed with CERT were included. Forty cases underwent preoperative assessment using 3D reconstructed imaging (3D-Cohort), while the remaining 40 cases were assessed using two-dimensional imaging (2D-Cohort). Vascular variations were evaluated by ascertaining the presence of renal arteries > 1, prehilar branching arteries, and arteries anterior to veins. The proposed scoring system, termed RAL, encompassed three critical components: (R)adius (maximal tumor diameter in cm), (A)rtery (occurrence of arterial variations), and (L)ocation relative to the polar line. Comparison of the RAL scoring system was made with established nephrometry scoring systems. ResultsA total of 48 (60 %) patients exhibited at least one vascular variation. In the 2D-Cohort, patients with vascular variations experienced significantly prolonged operation time, increased bleeding volume, and extended warm ischemia time compared with those without vascular variations. Conversely, the presence of vascular variations did not significantly affect operative parameters in the 3D-Cohort. Furthermore, the 2D-Cohort demonstrated a notable decline in both short- and long-term estimated glomerular filtration rate (eGFR) changes compared with the 3D-Cohort, a trend consistent across patients with warm ischemia time ≥ 25 min and those with vascular variations. Notably, the 2D-Cohort exhibited a larger margin of normal renal tissue compared with the 3D-Cohort. Elevated RAL scores correlated with larger tumor size, prolonged operation time, extended warm ischemia time, and substantial postoperative eGFR decrease. The RAL scoring system displayed superior predictive capabilities in assessing postoperative eGFR changes compared with conventional nephrometry scoring systems. ConclusionsOur proposed 3D vascular variation-based nephrometry scoring system offers heightened proficiency in preoperative assessment, precise prediction of surgical complexity, and more accurate evaluation of postoperative renal function in CERT patients.

Tribo-dynamic modeling method and application to three-dimensional flexible PRL system

Research on the tribo-dynamics of the piston-cylinder liner (PCL) and piston ring-cylinder liner (PRCL) is vital due to their role in generating over 50 % of total engine friction loss and the impact on carbon emissions. Traditional studies, hindered by the structural and functional differences between pistons and rings, required separate simulation models, often overlooking crucial coupling characteristics. A unified tribo-dynamics modeling method for the piston-ring-liner (PRL) system is proposed in this paper, integrating the ring pack and piston into one multi-body system. This article models with global coordinates, unifying the form of governing, film thickness, and load equations of discontinuous lubrication domains for more efficient dynamics-lubrication coupling. The described method is applied to a marine engine, and the new tribology characteristics discovered after calculations are exhibited. It shows how piston deformation impacts ring tribology, indicating that increased profile height reduces the squeezing effect by allowing more ring movement. Additionally, ring assembly position significantly affects tribology parameters' circumferential distribution. Installing the ring with the end gap facing the piston pin side should be avoided, as it maximizes the negative impact of elastic force and secondary motion, deteriorating lubrication.

Identifying problematic arteriovenous fistula with CFD-derived resistance: An exploratory study

Arteriovenous fistula (AVF) is the optimal form of vascular access for most haemodialysis dependant patients; however, it is prone to the formation of stenoses that compromise utility and longevity. Whilst there are many factors influencing the development of these stenoses, pathological flow-related phenomena may also incite the formation of intimal hyperplasia, and hence a stenosis. Repeated CFD-derived resistance was calculated for six patient who had a radiocephalic AVF, treated with an interwoven nitinol stent around the juxta-anastomotic region to address access dysfunction. A three-dimensional freehand ultrasound system was used to obtain patient-specific flow profiles and geometries, before performing CFD simulations to replicate the flow phenomena in the AVF, which enabled the calculation of CFD-derived resistance. We presented six patient cases who were examined before and after treatment and our results showed a 77% decrease in resistance, recorded after a surgical intervention to address access dysfunction. Problematic AVFs were found to have high resistance, particularly in the venous segment. AVFs with no reported clinical problems, and clinical patency, had low resistance in the venous segment. There did not appear to be any relationship with clinical problems/patency and resistance values in the arterial segment. Identifying changes in resistance along the circuit allowed stenoses to be identified, independent to that determined using standard sonographic criteria. Our exploratory study reveals thatCFD-derived resistance is a promising metric that allows for non-invasive identification of diseased AVFs. The pipeline analysis enabled regular surveillance of AVF to be studied to aid with surgical planning and outcome, further exhibiting its clinical utility.

Structural diversity of transition-metal coordination polymers and dinuclear metallocycles constructed by bispyridyl-substituted diphthalic diimide ligands

Four coordination polymers (CPs), namely, {[Ni(L1)2Cl2]·(CHCl3)}n(1), {[Co(L1)1.5(NO3)2]·(CHCl3)}n (2), {[Ag2(L2)2(NO3)2]·(CHCl3)}n (3), [Cd(L2)2(Cl)2]n (4), and two dinuclear metallocycles, namely, {[Zn2(L3)2(Cl)4]·2CHCl3}n (5) and [Cu2(L3)2(Cl)4] (6), (L1 = 2,2′-bis(pyridin-3-ylmethyl)-[5,5′-biisoindoline]-1,1′,3,3′-tetraone), L2 = 5,5′-oxybis(2-(pyridin-3-ylmethyl)isoindoline-1,3-dione), L3 = 5,5′-carbonylbis(2-(pyridin-3-ylmethyl)isoindoline-1,3-dione)), have been adeptly constructed using solvothermal conditions and successfully delineated by non-destructive single-crystal (X-ray) diffraction. Structural analyses provide insights into a two-dimensional (2D) 44 grid layer of complex 1 and a three-dimensional (3D) 63 network of 2. Additionally, the connection between these two complexes is established via hydrogen bonding (CH···O) to further accomplish a three-dimensional (3D) supramolecular framework system. Similarly, Complex 3 and 4 possess a one-dimensional (1D) wave-like chain and loop-like chains composed of olive-like metallacycle building units, respectively. These chains are bridged by CH···O hydrogen bond and π∙∙∙π stacking interactions to generate 3D supramolecular structure. Finally, complexes 5 and 6 occupies zero-dimensional (0D) square-like array also called as olive-like dimeric M2L2 metallacycles. The distinct structural configurations of the six complexes are in close alliance with different conformations of the N-donor pyridyl ligands and coordination arrangement of the transition metal centers.

Value of the three-dimensional visualization ablation planning system in ultrasound-guided percutaneous microwave ablation for malignant adrenal tumors: A clinical comparative study.

We aimed to assess the efficacy and safety of the three-dimensional visualization ablation planning system (3DVAPS) in ultrasound-guided percutaneous microwave ablation (US-PMWA) for malignant adrenal tumors (MATs). A retrospective analysis was conducted on a cohort of 62 unilateral MAT cases from March 2011 to November 2022. There were a total of 62 lesions, with a mean maximum diameter of 5.4 ± 2.7 cm (range, 1.4-15.7 cm). The patients were categorized into the following, based on the pre-operative planning method: 3D planning (n = 32) and 2D planning (n = 30) groups. A comparative analysis was performed on various parameters, including ablation techniques, tumor-related prognosis, and incidence of complications. This analysis encompassed indicators, such as overall survival (OS) rate and local tumor progression (LTP), among others. The median follow-up period was 30 months (range, 3-84 months). Notably, compared with the 2D planning group, the 3D planning group exhibited significant disparities in the number of punctures (P = 0.035) and incidence of complications (P = 0.029) and had no significant difference in the OS ( P > 0.05) but had a significantly lower LTP rate (6.2% vs. 23.3%, P = 0.033). In the 3D planning group, the sub-group with a tumor diameter of < 5 cm exhibited a significantly less number of punctures ( P = 0.039), lower input energy ( P = 0.002), and a shorter ablation time ( P = 0.001), compared with the sub-group with a tumor diameter of ≥ 5 cm, but there was no significant difference in the LTP and OS rates between the two sub-groups ( P > 0.05). The use of 3DVAPS in US-PMWA of MATs was advantageous, especially in lesions with a diameter of ≥ 5 cm. It can help in developing more rational surgical plans, reducing the incidence of complications, and extending the local recurrence-free survival time of patients and can add a certain value for precise treatment and expand the indications for ablation.

In vitro throughput screening of anticancer drugs using patient-derived cell lines cultured on vascularized three-dimensional stromal tissues

The development of high-throughput anticancer drug screening methods using patient-derived cancer cell (PDC) lines that maintain their original characteristics in an in vitro three-dimensional (3D) culture system poses a significant challenge to achieving personalized cancer medicine. Because stromal tissue plays a critical role in the composition and maintenance of the cancer microenvironment, in vitro 3D-culture using reconstructed stromal tissues has attracted considerable attention. Here, a simple and unique in vitro 3D-culture method using heparin and collagen together with fibroblasts and endothelial cells to fabricate vascularized 3D-stromal tissues for in vitro culture of PDCs is reported. Whereas co-treatment with bevacizumab, a monoclonal antibody against vascular endothelial growth factor, and 5-fluorouracil significantly reduced the survival rate of 3D-cultured PDCs to 30%, separate addition of each drug did not induce comparable strong cytotoxicity, suggesting the possibility of evaluating the combined effect of anticancer drugs and angiogenesis inhibitors. Surprisingly, drug evaluation using eight PDC lines with the 3D-culture method resulted in a drug efficacy concordance rate of 75% with clinical outcomes. The model is expected to be applicable to in vitro throughput drug screening for the development of personalized cancer medicine. Statement of significanceTo replicate the cancer microenvironment, we constructed a cancer-stromal tissue model in which cancer cells are placed above and inside stromal tissue with vascular network structures derived from vascular endothelial cells in fibroblast tissue using CAViTs method. Using this method, we were able to reproduce the invasion and metastasis processes of cancer cells observed in vivo. Using patient-derived cancer cells, we assessed the possibility of evaluating the combined effect with an angiogenesis inhibitor.Further, primary cancer cells also grew on the stromal tissues with the normal medium. These data suggest that the model may be useful for new in vitro drug screening and personalized cancer medicine.

Analysis of a new three-dimensional jerk chaotic system with transient chaos and its adaptive backstepping synchronous control

A new three-dimensional Jerk chaotic system with line equilibrium points is proposed. The system is researched in detail by the Lyapunov exponent graph, bifurcation diagram, phase diagram, and time domain waveform diagram, which show that the system has rich dynamical behaviors, such as eight types of coexisting attractors, extreme multistability of four different attractor states, and offset boosting in two directions. In addition, the system also has six types of transient chaos, which greatly increase the complexity of the system. We study the variation of the spectral entropy (SE) and C0 complexity when the system takes different initial values. Also, in this paper, the initial conditions under which the system is in a synchronized state are determined by initial values with higher complexity. The correctness of the theoretical analysis and numerical simulation is verified by circuit simulation and hardware experiments. Finally, the new system achieves synchronization control utilizing a designed adaptive backstepping controller, laying the foundation for its subsequent use in secure communications.

Radiofrequency catheter ablation for redo procedures after pulmonary vein isolation with the cryoballoon technique: 9-year outcome

Abstract Catheter ablation has become the first line of therapy in patients with symptomatic, recurrent, drug-refractory atrial fibrillation. Cryoablation has been shown to be a safe and effective technique for pulmonary vein isolation. However, there is a significant arrhythmia recurrence rate after cryoablation procedures and there are no established strategies for redo procedures in these patients. Therefore, we have summarized our experience with radiofrequency catheter ablation for redo procedures after pulmonary vein isolation with the cryoballoon technique (including an analysis of pulmonary vein conduction recovery patterns after procedures performed with the first or second generation cryoballoon). Methods Two hundred and twenty patients (paroxysmal AF: 140 patients, persistent AF: 80 patients) had to undergo a redo procedure after initially successful circumferential PV isolation with the cryoballoon technique (First generation: 110 patients (group A); second generation: 110 patients (group B)). The redo ablation procedures were performed using a segmental approach or a circumferential ablation strategy (three-dimensional mapping system) depending on the intra-procedural findings. Results During the redo procedure, a mean number of 1.6 re-conducting PVs were detected (using a circular mapping catheter; group A: 2.2 re-conducting PVs, group B: 1.0 re-conducting PVs). There was a slightly higher incidence of chronic PV reconnections related to the left-sided PV ostia than to the right-sided PVs in both groups. Furthermore, sites of chronic PV reconnection were found more frequently in the inferior parts of the PV ostia than in the superior parts. In 97 patients in group A, a segmental approach was sufficient to eliminate the residual PV conduction because there were only a few recovered PV fibers (1-3 reconnected PVs; group A1). In the remaining 13 patients in group A, a circumferential ablation strategy was used because of a complete recovery of the PV-LA conduction of all four pulmonary veins (group A2). In group B, a segmental approach was sufficient in nearly all patients (109/110) because there was only a minor reconnection of 1-2 PVs. All recovered PVs could be isolated sucessfully again. At 108-month follow-up, 69.1 % of all patients were free from an arrhythmia recurrence (152/220 patients; group A: 72/110 patients (65.5 %), group B: 80/110 patients (72.3 %)). There were no major complications in both groups. Conclusions In patients with an initial circumferential PVI using the cryoballoon technique, a repeat ablation procedure can be performed safely and effectively using radiofrequency catheter ablation. In most cases only a few re-conducting PV fibers were found and therefore, a segmental re-ablation approach seems to be sufficient in the majority of patients (especially in patients treated with the second generation cryoballoon).

Intermittent hypoxia is significantly associated with low-voltage areas in patients with atrial fibrillation complicated by obstructive sleep apnea

Abstract Background Obstructive sleep apnea (OSA) is one of risk factors for atrial fibrillation (AF); however, how OSA affects the structural and electrical atrial remodeling is not well described. This study aimed to determine the association of OSA with left atrial (LA) size and LA low-voltage area (LVA), a known arrhythmogenic substrate for AF. Methods Eighty-three patients undergoing catheter ablation of AF (forty-nine with OSA [apnea–hypopnea index: AHI ≥ 5/h] and thirty-four control patients without OSA by full polysomnography or portable monitor) were studied. In all cases, LA maps were created using a three-dimensional electro-anatomical mapping system in sinus rhythm or pacing from the right atrium. LVA was defined as a bipolar voltage &amp;lt; 0.5 mV. %LVA is defined as ratio of LVA to LA area. Results LVA and %LVA were larger in OSA group as compared to Control group (6.0 ± 6.6 vs. 2.6 ± 3.2 cm2, P = 0.003 and 7.5 ± 8.5 vs. 3.5 ± 4.6 %, P = 0.008, respectively). On the other hand, there was no difference in LA size between the two groups. In addition, 3% oxygen desaturation index (ODI) was significantly correlated with %LVA (r = 0.282, P = 0.010), but not with LA size (r = 0.053, P = 0.637). Multiple regression analysis demonstrated that 3%ODI ≥ 30 (3.088, 1.078-8.851, P = 0.036) was significantly associated with %LVA after adjustment. Conclusion In patients with AF complicated by OSA, significant enlargement of the LVA was observed, but there was no evidence of enlargement in LA size. Intermittent hypoxia may be one of the mechanisms of this atrial electro-anatomical remodeling.figure 1figure 2

Reliability of Obstacle-Crossing Parameters during Overground Walking in Young Adults.

We aimed to evaluate the intra-session relative and absolute reliability of obstacle-crossing parameters during overground walking in young adults, and to determine the number of trials required to ensure reliable assessment. We analysed data from 43 young male adults who were instructed to walk at a self-selected velocity on a pathway and to step over an obstacle (height = 15 cm; width = 80 cm, thickness = 2 cm) three times. Spatial-temporal gait parameters of the approaching and crossing phases (i.e., before and after the obstacle) and obstacle clearance parameters (i.e., vertical and horizontal distance between the foot and the obstacle during crossing) were computed using a three-dimensional motion analysis system. Intraclass correlation coefficients were used to compute the relative reliability, while standard error of measurement and minimal detectable change were used to assess the absolute reliability for all possible combinations between trials. Results showed that most spatial-temporal gait parameters and obstacle clearance parameters are reliable using the average of three trials. However, the mean of the second and third trials ensures the best relative and absolute reliabilities of most obstacle-crossing parameters. Further works are needed to generalize these results in more realistic conditions and in other populations.

An Enhanced Indoor Three-Dimensional Localization System with Sensor Fusion Based on Ultra-Wideband Ranging and Dual Barometer Altimetry.

Accurate three-dimensional (3D) localization within indoor environments is crucial for enhancing item-based application services, yet current systems often struggle with localization accuracy and height estimation. This study introduces an advanced 3D localization system that integrates updated ultra-wideband (UWB) sensors and dual barometric pressure (BMP) sensors. Utilizing three fixed UWB anchors, the system employs geometric modeling and Kalman filtering for precise tag 3D spatial localization. Building on our previous research on indoor height measurement with dual BMP sensors, the proposed system demonstrates significant improvements in data processing speed and stability. Our enhancements include a new geometric localization model and an optimized Kalman filtering algorithm, which are validated by a high-precision motion capture system. The results show that the localization error is significantly reduced, with height accuracy of approximately ±0.05 m, and the Root Mean Square Error (RMSE) of the 3D localization system reaches 0.0740 m. The system offers expanded locatable space and faster data output rates, delivering reliable performance that supports advanced applications requiring detailed 3D indoor localization.

Categorizing knee hyperextension patterns in hemiparetic gait and examining associated impairments in patients with chronic stroke

BackgroundPost-stroke hemiparetic gait exhibits considerable variations in motion patterns and abnormal muscle activities, notably knee hyperextension during the stance phase. Existing studies have primarily concentrated on its joint angle or moment. However, the underlying causes remain unclear. Thus, the causes of knee hyperextension were explored from a new perspective based on temporal-durational factors. Research QuestionDoes the temporal-durational difference of knee hyperextension presence result from specific decreased motor functions? MethodsBarefoot gait at a comfortable speed was captured using a three-dimensional camera system. Scores of knee hyperextension used a metric with the temporal-durational factor of knee hyperextension presence in each of four stance phases (1st double support, DS1; early single-leg stance, ESS; late single-leg stance, LSS; 2nd double support, DS2). These scores were used in cluster analysis. The classification and regression tree analysis characterizing each knee hyperextension cluster used the clinical measures of the lower limb and trunk motor function, muscle strength, and spasticity as explanatory variables. ResultsThirty patients with hemiparetic chronic stroke who exhibited knee hyperextension during gait were included. Four knee hyperextension clusters were shown: Momentary (almost no hyperextension), Continuous (DS1–DS2), ESS–LSS, and ESS–DS2. Knee flexor strength was lower in the groups with long hyperextension durations (Continuous and ESS–DS2) compared with short durations (ESS–LSS and Momentary). ESS–DS2 exhibited higher trunk motor function than Continuous, whereas more severe spasticity was observed in ESS–LSS than in Momentary. SignificanceThis study successfully classified four hemiparetic gait patterns with knee hyperextension based on the temporal-durational factor, providing valuable perspectives for understanding and addressing specific functional physical impairments. These findings offer guidance for focusing on related physical functions when striving for gait improvement with knee hyperextension and are expected to serve as a reference for treatment decision-making.