Position Of Device Research Articles

3D Remote Assistance for NDT Inspections

In this work, we present a system architecture that is especially designed for remote ultrasound testing inspections (UT). The system itself is realized using a real-time session service and a web service based on a REST API (REST: Representational State Transfer; API: application programming interface). This web service is used to store data persistently, e.g., sample geometries, raw nondestructive testing (NDT) data and derived inspection results in a shared dataspace. In the current development state, the results consist of textures mapped onto the sample geometry. This approach allows us to display the UT results directly on the real sample using mixed reality technologies. We also implemented a feature to assist the inspector remotely by making use of the availability of this digital representation. Hence, it is necessary to share additional data like the current UT-signal, temporary position marks, user and device positions, etc. between the different participants. A real-time distribution of this highly dynamic data is required to create an effective assistance environment. Therefore, a separate session service is used. The inspection data generated in this temporary session can also be transferred to the afore mentioned dataspace to be saved persistently. The system features mixed reality visualization for the inspector and optionally a virtual reality or a 3D Desktop environment for one or more remote assistants.

Clock synchronizing radio access networks to picosecond precision using optical clock distribution and clock phase caching

Performing positioning of future mobile devices using trilateration through radio access networks would provide a robust alternative to currently used global navigation satellite systems. However, the positioning accuracy is strongly dependent on the time synchronization accuracy of the antennas used as location reference points. Consequently, achieving sub-30 cm positioning accuracies requires the synchronization of radio access network antennas to sub-nanosecond accuracy. Here we show a clock phase synchronization and optical clock signal distribution approach to clock synchronization in radio access networks that achieves 0.98-ps root-mean-square precision clock synchronization, in a real-time field-trial demonstration on 37.6-km dark fiber, with optical clock frequency synchronization and clock phase caching operating using 25.6-Gb/s commercial transceivers. We quantify the clock synchronization performance of our approach using standard metrics, including time deviation (TDEV) and mean time interval error (MTIE). Furthermore, we estimate the impact of varying the phase update rate used in clock phase caching on the clock synchronization performance of our approach. Through our two combined approaches, we explore a route towards achieving sub-nanosecond clock synchronization in radio access networks.

Analysis of a Novel Automated Positioning Device

As a matter of fact, with the development of science and technology and the advancement of industrialization, automation equipment is more and more widely used in all walks of life, which deep into every link of the production line. With this in mind, whether it is automated manufacturing equipment or home and office automation equipment, they are greatly improving the productivity and quality of life. However, many existing automation equipment still face some challenges in practical applications. On this basis, this study proposed a novel automated positioning devices in order to solve certain limitation issues. To be specific, the innovation analysis and facility fabrication are demonstrated. According to the analysis, it is believed that the new designs will have better ability as well as performance. The possible improvements are also claimed and the further ability enhancements are also evaluated. Overall, these results shed light on guiding further exploration of automated positioning device.

Feasibility of contrast-free left atrial appendage closure with WATCHMAN FLX device for patients with chronic kidney disease.

Contrast media are generally necessary for transcatheter left atrial appendage closure (LAAC), however, it should be avoided in patients with chronic kidney disease (CKD). The objective of this study was to evaluate the safety and feasibility of contrast-free LAAC with WATCHMAN FLX device for patients with CKD. Among 141 patients undergoing LAAC using the WATCHMAN FLX between May 2021 and March 2023, we performed LAAC without contrast media in 10 patients. Procedural and follow-up results were evaluated. The device size was selected based on the transesophageal echocardiographic (TEE) measurements. The device shape was assessed by fluoroscopy, and the device position was adjusted by TEE images. The mean age was 78 ± 4.9years, CHADS2 score was 3.2 ± 1.1, and the estimated glomerular filtration rate (eGFR) was 28 ± 12mL/min/1.73m2. The procedure was completed without contrast media in ten patients. Partial recapture of the device was required in four patients, but the initially selected device was finally implanted in all patients. Mean procedure time was significantly shorter in the contrast-free LAAC than in the contrast-use LAAC (41.6 ± 14.1min vs 30.3 ± 7.6min, p = 0.01). Postprocedural eGFR did not change from baseline, and there were no adverse events during the hospital stay. Follow-up TEE or cardiac computed tomography performed within 3months after the procedure revealed no device-related thrombus or peri-device leak > 3mm, and oral antithrombotic therapy was discontinued in all patients. Our experience shows that contrast-free LAAC using the WATCHMAN FLX device was safe and feasible. Non-contrast LAAC is one of the therapeutic options for patients with severe CKD.

Development and evaluation of ultrasound navigation for free-hand biopsies of small masses in the head and neck area

Ultrasound is an important imaging method in the head and neck area. It is readily available, dynamic, inexpensive, and does not involve radiation exposure. Interventions in the complex head and neck anatomy require good orientation, which is supported by navigation systems. This work aimed to develop anew ultrasound-controlled navigation system for taking biopsies of small target structures in the head and neck region. Aneck phantom with sonographically detectable masses (size: 8-10 mm) was constructed. These were automatically segmented using aResNet-50-based deep neural network. The ultrasound scanner was equipped with an individually manufactured tracking tool. The positions of the ultrasound device, the masses, and apuncture needle were recorded in the world coordinate system. In 8out of 10cases, an 8‑mm mass was hit. In aspecial evaluation phantom, the average deviation was calculated to be 2.5 mm. The tracked biopsy needle is aligned and navigated to the masses by auditory feedback. Outstanding advantages compared to conventional navigation systems include renunciation of preoperative tomographic imaging, automatic three-dimensional real-time registration that considers intraoperative tissue displacements, maintenance of the surgeon's optical axis at the surgical site without having to look at anavigation monitor, and working freely with both hands without holding the ultrasound scanner during biopsy taking. The described functional model can also be used in open head and neck surgery.

Evolutionary Algorithm-Based Attack Strategy With Swarm Robots in Denied Environments

An attack-defense confrontation problem arises from a robot swarm attacking a territory protected by another one. In denied environments, global positioning and communication are hardly available. It becomes difficult for a swarm to realize collaboration and handle confrontation against another. Commonly-used deep reinforcement learning relies on pre-training, which is time-consuming and has strong environmental dependence, especially in denied environments. To study attack strategies in denied environments, this work proposes a novel Evolutionary Algorithm-based Attack Strategy with Swarm Robots for the first time. Each robot obtains its situation information through perceiving its nearby peers and enemies. Such information is utilized to evaluate the benefits or threats of a robot’s next perceptible attack positions. Then, each robot uses the evolutionary algorithm to optimize its fitness function and searches for its optimal position. A collision avoidance strategy is integrated into the algorithm. Hence, a robot swarm realizes collaboration and handles confrontation as long as each robot can sense its surroundings. They utilize their own sensors to detect others locally without using global positioning and communication devices. The experimental analyses show that the evolutionary algorithm-based attack strategy has better scalability and more potential in solving large-scale confrontational problems than the deep reinforcement learning-based algorithms. Rationales of the proposed method is presented to verify the great capability of the proposed method.

Towards Smarter Positioning through Analyzing Raw GNSS and Multi-Sensor Data from Android Devices: A Dataset and an Open-Source Application

The state-of-the-art Android environment, available on a major market share of smartphones, provides an open playground for sensor data gathering. Moreover, the rise in new types of devices (e.g., wearables/smartwatches) is further extending the market opportunities with a variety of new sensor types. The existing implementations of biometric/medical sensors can allow the general public to directly access their health measurements, such as Electrocardiogram (ECG) or Oxygen Saturation (SpO2). This access greatly increases the possible applications of these devices with the combination of all the onboard sensors that are broadly in use nowadays. In this study, we look beyond the current state of the art into the positioning capacities of Android smart devices and wearables, with a focus on raw Global Navigation Satellite Systems (GNSS) measurements that are still mostly lacking in the research world. We develop a novel open-source Android application working in both smartphone and smartwatch environments for multi-sensor measurement data logging that also includes GNSS, an Inertial Navigation System (INS) magnetometer, and a barometer. Four smartphones and one smartwatch are used to perform surveys in different scenarios. The extraction of GNSS raw data from a wearable device has not been reported yet in the literature and no open-source app has existed so far for extracting GNSS data from wearables. Not only the developed app but also the results of these measurement surveys are provided as an open-access dataset. We start by defining our methodology and the acquisition protocol, and we dive into the structure of the dataset files. We also propose a first analysis of the data logged and evaluate the data according to several performance metrics. A discussion reviewing the capacities of smart devices for advanced positioning is proposed, as well as the current open challenges.

Registration in the supine position improve the accuracy of cup placement in total hip arthroplasty using a portable navigation system

Portable navigation systems have been developed for use in total hip arthroplasty (THA) in recent years. Although intraoperative registration in the lateral decubitus position or the supine position is need to create the three-dimensional coordinate system, it is not clear which position is appropriate. The purpose of this study was to assess the accuracy of cup placement in primary THA in the lateral decubitus position using an image-free handheld navigation device with registration in the lateral decubitus or the supine position, and clarify which position is appropriate. This retrospective study included 129 consecutive cementless THAs performed using an image-free handheld navigation device in the lateral decubitus position. Registration in the first 68 hips was performed in the lateral decubitus position and the last 61 hips was performed in the supine position. Postoperative cup radiographic inclination and radiographic anteversion were assessed, and the accuracy was compared between the two groups. The mean absolute errors of the postoperative measured inclination and anteversion from the target angles were 3.9° ± 2.2° and 4.8° ± 3.5° in the lateral group and 2.9° ± 2.7° and 3.2° ± 2.7° in the supine group (p < 0.05). The percentage of cups inside Lewinnek’s safe zone was 94% in the lateral group and 95% in the supine group (ns). The mean absolute values of navigation error in inclination and anteversion were 3.1° ± 2.1° and 4.2° ± 2.8° in the lateral group and 2.3° ± 2.0° and 3.1° ± 2.4° in the supine group (p < 0.05 and p < 0.05). Registration in the supine position improved the accuracy of cup insertion compared with the lateral decubitus position in THA using an image-free handheld navigation device in the lateral decubitus position.

Supported standing and stepping device use in young children with cerebral palsy, gross motor function classification system III, IV and V: A descriptive study

ABSTRACT This study described and compared use of supported-standing and stepping devices by young children with cerebral palsy, Gross-Motor Function Classification System (GMFCS) levels III-V following power mobility introduction. Data was collected at two time-points, 5–6 months apart, for 42 participants, aged 18–80 months, using the Home Use of Technology for CHildren (HUTCH). Supported-standing and stepping device choice and time in each device remained stable over 6 months. Associations between device use and three functional classifications were examined. Children with more impaired motor, postural and manual abilities were more likely to use a supine stander rather than a prone/upright stander or no stander. Children at GMFCS V tended to use hands-free stepping devices, while support-arms stepping devices were more common for children at GMFCS IV. Only children at GMFCS III used convertible stepping devices. Using power mobility, standers and supported-stepping devices was feasible and 19/34 classified at GMFCS IV/V used all three devices over 6 months. A key finding was that introduction of power mobility did not reduce use of supported-stepping devices at any GMFCS level. Use of multiple upright positioning and mobility devices may assist children with limited mobility to be actively engaged and participate in daily life.

Effect of left atrial appendage occlusion device type and position on potential determinants of device-related thrombus

Abstract Introduction Device-related thrombus (DRT) after left atrial appendage occlusion (LAAO) is potentially linked to adverse events. Clinical reports suggest an association between the device type/position and the DRT risk, in-depth studies of its mechanistic basis are needed. Purpose To generate in silico model with precise geometry of LAAO devices and assess the impact of device type and position on local hemodynamics and surrogate markers of DRT risk. Methods Watchman (plug-type device) and Amulet (pacifier device) LAAO devices were modeled with precise geometry and virtually implanted in different positions into a patient-specific left atrium. Using computational fluid dynamics, the following surrogate markers of thrombogenicity were quantified: residual blood, wall shear stress (WSS) and endothelial cell activation potential (ECAP). Results In comparison to ostium-fitted device positions, deep implantations were associated with more residual blood surrounding the device (after six cardiac cycles: plug-type device 12% vs 8%; pacifier device 6% vs 5%). Furthermore, deep implantations resulted in lower average WSS that indicates increased risk in platelet adhesion (plug-type device 0.21 vs. 0.26 Pa; pacifier device 0.30 vs 0.35 Pa) and higher ECAP that represents higher potential in endothelial dysfunction (plug-type device 2.23 vs. 0.85 Pa-1; pacifier device 0.16 vs 0.10 Pa-1). For plug-type device, an off-axis orientation towards mitral valve resulted in even more residual blood (15% vs. 8%), higher ECAP (1.10 vs. 0.85 Pa-1) and a similar average WSS as compared to an ostium-fitted device position. In addition, the precise geometry of the LAAO device models allowed indication of residual blood accumulation on the device’s atrial surface surrounding the threaded insert as well as on the lateral device surface and on the left atrium tissue around the device landing zone. Similarly, low WSS and high ECAP were mostly found in these areas, suggesting an increased risk for potential thrombus in these areas, which corresponds to the clinical observational series. Conclusions This study demonstrated the effect of LAAO device type and position on potential DRT risk factors. In comparison to the plug-type device, the pacifier device showed lower blood stasis, platelet adhesion and endothelial dysfunction and, therefore, lower DRT risk. For both device types, deep implantations are associated to higher surrogate markers of DRT compared to ostium-fitted device positions. In addition, an off-axis device position of plug-type device were associated with higher DRT risk.

Development of an in vitro platform for transesophageal echocardiographic and color Doppler hemodynamic assessments of left atrial appendage occlusion devices

Abstract Introduction Device-related thrombus (DRT) remains a significant complication after left atrial appendage occlusion (LAAO) and is associated with device position. Clinical prospective study of the influence of device position on DRT is cumbersome. Purpose To establish an in vitro bench test platform that allows visual, transesophageal echocardiographic and color Doppler hemodynamic assessments of left atrial appendage occlusion devices. Methods Based on a mock circulatory system, an in vitro platform was developed to create pathophysiological environment and left atrium wall motion under atrial fibrillation condition. Results LAAO devices could be visualized in the left atrium phantom model using transesophageal echocardiography and color Doppler measurement of local blood velocity at LAAO devices were proven to be capable. Deep implantations resulted in uncovered left upper pulmonary vein ridges. In comparison to ostium-fitted device positions, deep implantations were associated with reduced velocity of blood and the local velocity in the "cul-de-sac" remained lower than the critical threshold of 0.2 m/s. Conclusions An in vitro platform was developed that allows transesophageal echocardiographic and color Doppler hemodynamic assessments of left atrial appendage occlusion devices.

Accuracy of computer-assisted design and manufactured three-dimensional device for condylar positioning in mandibular bilateral sagittal split osteotomy (clinical trial)

Aligning dental arches in orthognathic treatment after undergoing LeFort I osteotomy or bilateral sagittal split osteotomy (BSSO) relies on occlusal splints, which do not provide precise control over the condylar head. To clinically and radiographically assess the accuracy of computer-assisted design and manufactured (CAD/CAM) surgical guide for condylar positioning in a BSSO. The study recruited 8 patients with a non-syndromic dentofacial deformity who underwent a BSSO. Surgery was planned according to CAD/CAM technology. After osteotomy, a pre-operative guide was used, followed by a repositioning guide. Computed tomography scans were conducted on all patients 1 week pre-operatively, immediately, and 3 months postoperatively. The data are presented as median values with the 25th and 75th percentiles. Eight patients (37.50% females and 62.50% males) between the ages of 19 and 24 underwent BSSOs. The surgical procedure successfully corrected their skeletal deformities. The absolute change between immediate postoperative and pre-operative condylar angle was 0.15 (0.00-0.3). The absolute change between 3 months postoperative and pre-operative condylar angle was 0.20 (0.00-0.30). The stability of the condylar head in position is well assessed by 3-dimensional condylar positioning devices designed and manufactured by CAD/CAM technology in the mandibular BSSO.

Clinical and Hemodynamic Outcomes of Balloon-Expandable Mitral Valve-in-Valve Positioning and Asymmetric Deployment: The VIVID Registry

BackgroundMitral valve-in-valve (ViV) is associated with suboptimal hemodynamics and rare left ventricular outflow tract (LVOT) obstruction. ObjectivesThis study aimed to determine whether device position and asymmetry are associated with these outcomes. MethodsPatients undergoing SAPIEN 3 (Edwards Lifesciences) mitral ViV included in the VIVID (Valve-in-Valve International Data) Registry were studied. Clinical endpoints are reported according to Mitral Valve Academic Research Consortium definitions. Residual mitral valve stenosis was defined as mean gradient ≥5 mm Hg. Depth of implantation (percentage of transcatheter heart valve [THV] atrial to the bioprosthesis ring) and asymmetry (ratio of 2 measures of THV height) were evaluated. ResultsA total of 222 patients meeting the criteria for optimal core lab evaluation were studied (age 74 ± 11.6 years; 61.9% female; STS score = 8.3 ± 7.1). Mean asymmetry was 6.2% ± 4.4%. Mean depth of implantation was 19.0% ± 10.3% atrial. Residual stenosis was common (50%; mean gradient 5.0 ± 2.6 mm Hg). LVOT obstruction occurred in 7 cases (3.2%). Implantation depth was not a predictor of residual stenosis (OR: 1.19 [95% CI: 0.92-1.55]; P = 0.184), but more atrial implantation was protective against LVOT obstruction (0.7% vs 7.1%; P = 0.009; per 10% atrial, OR: 0.48 [95% CI: 0.24-0.98]; P = 0.044). Asymmetry was found to be an independent predictor of residual stenosis (per 10% increase, OR: 2.30 [95% CI: 1.10-4.82]; P = 0.027). ConclusionsValve stenosis is common after mitral ViV. Asymmetry was associated with residual stenosis. Depth of implantation on its own was not associated with residual stenosis but was associated with LVOT obstruction. Technical considerations to reduce postdeployment THV asymmetry should be considered.

Transcatheter closure of large ostium secundum atrial septal defects in symptomatic small children: A single-center retrospective study.

In general, the risks associated with transcatheter atrial septal defect (ASD) device closure are reported to be relatively low, but the evidence stems from trials involving adults and older children. Current guidelines do not recommend ASD device closure in children with defect sizes >20 mm due to limited data available in this group of patients. This retrospective study sought to determine the clinical and procedural characteristics of successful transcatheter ASD device closure in small children with large defects and assess the complication rates and reasons for unsuccessful device closure. We retrospectively reviewed the data of all patients who underwent elective transcatheter closure of ostium secundum ASD in our department between September 2013 and February 2022. All children weighing <20 kg, requiring a device of size 20 mm or greater, were included. Major and minor complications were predefined and indications for referral were evaluated. Echocardiogram reports were reviewed from the time of referral, postcatheterization day 1, and at 1-year follow-up. We identified 40 patients meeting inclusion criteria with a median (interquartile range [IQR]) procedural age of 5 (4-7) years and median (IQR) weight of 14 (12-18) kg. Successful device closure was achieved in 39 patients with a success rate of 97.5%. The total complication rate was 2.5% (95% confidence interval: 0.44%- I2.8%) with only 1 major complication. All children had right heart enlargement and exertional dyspnea, 30% of patients had recurrent lower respiratory tract infections, and 10% had failure to thrive. At 1-year follow-up, a transthoracic echocardiogram showed a well-endothelialized device in a stable position in all the patients, and none of the patients had a residual shunt. In experienced centers, percutaneous ASD closure of large defects in symptomatic small children can be done effectively and safely with a great degree of predictability and a low complication rate.

Novel Monthly Quality Assurance Regimen and 5-Year Analysis Using a Proton Metrology System

PurposeTo develop a novel, monthly quality assurance (QA) regimen for a proton therapy system that uses 2 custom phantoms, each housing a commercial scintillator detector and a charge-coupled device camera. The novel metrology system assessed QA trends at a pediatric proton therapy center from 2018 to 2022. Materials and MethodsThe measurement system was designed to accommodate horizontal and vertical positioning of the commercial device and to enable gantry and couch isocentricity measurements (using a star shot procedure), proton spot profile verification, and imaging and radiation congruence tests to be performed simultaneously in the dual-phantom setup. Gantry angles and proton beam energies were varied and alternated each month, using gantry angles of 0°, 30°, 60°, 90°, 120°, 150°, and 180° and discrete beam energies of 69.4, 84.5, 100, 139.1, 180.4, 200.4, and 221.3 MeV after radiographic verification. A total of 1176 individual monthly QA measurements of gantry and couch isocentricity, spot size, and congruence were analyzed. ResultsGantry and couch star shot measurements showed beam isocentricities of 0.3 ± 0.2 mm and 0.2 ± 0.2 mm, respectively, which were within the threshold of 1.0 mm. Spot sizes for each discrete energy were within the threshold of ± 10% of the baseline values for all 3 proton rooms. The imaging and radiation coincidence test results for the 1176 individual monthly QA measurements were 0.5 mm for the 50th percentile and 1.2 mm (the clinical threshold) for the 97.6th percentile. ConclusionsIntegrating a commercial device with custom phantoms improved the quality of proton system checks compared with previous methods using radiochromic films, loose ball bearings, and foam. The scheme of alternating beam angles with discrete energies in the monthly QA-enabled, clinically meaningful verification of beam energy and gantry angle combinations while the machine performance and accuracy were being checked.

Power Mobility, Supported Standing and Stepping Device Use in the First Two Years of Life: A Case Report of Twins Functioning at GMFCS V

Mobility experience has a positive impact on activity, participation, socialisation, language and cognition, but children with cerebral palsy (CP), Gross Motor Function Classification System (GMFCS) level V require assistive devices or assistance in all environments. Supported standing devices afford upright, weight-bearing positions to promote muscle, bone, joint and overall health. Supported stepping devices afford stepping and upright independent mobility, positively impacting self-esteem and participation, while power mobility is the only possibility for effective, independent community mobility. These devices and opportunities should be introduced at the age when children who are typically developing are pulling to stand, moving and exploring their environment. A detailed case description including lived experience and device use data is presented for female twins with dystonic tetraplegic CP born at 25 weeks gestational age and functioning at GMFCS level V. The feasibility of using power mobility, standing and stepping devices in home and community settings within the first two years is illustrated. The twins transitioned from spending 24 h in lying positions or being held in arms to spending more than 2 h daily in upright positions and having opportunities to move independently. Positioning and mobility devices can help to address all the F-words for child development: functioning, family, fitness, fun, friends and future.

Radio Map-Based Trajectory Design for UAV-Assisted Wireless Energy Transmission Communication Network by Deep Reinforcement Learning

In this paper, we consider a wireless energy-carrying communication network of a UAV. In this communication network, the internet of things (IoT) devices maintain their work via the power supply of batteries. The energy of batteries is slowly consumed over time. The UAV adopts the full-duplex working mode and the flight hover protocol, that is, they can power the target device in the hover position and collect base station data at the same time. Unlike traditional methods, which seek to achieve wireless energy transmission, this paper adopts deep reinforcement learning. On the one hand, the deep reinforcement learning algorithm seeks to solve the dynamic programming problem without a model. The traditional method often requires a prior channel model, to form a formula about variables for convex optimization, while reinforcement learning only requires the interaction between agents and the environment. Then, the strategy is optimized according to the reward function feedback. On the other hand, traditional optimization methods generally solve static programming problems. Since IoT devices constantly collect information from the surrounding physical environment, and their requirements for power supply change dynamically, traditional methods are relatively complex and require huge computational overhead, while deep reinforcement learning performs well in complex problems. The purpose of our work is that with the assistance of the radio map, a UAV can find the best hover position, maximize the energy supplied by the UAV, maximize the data throughput collected, and minimize the energy consumption. The simulation results show that the proposed algorithm can well find the best hovering position of the UAVs and significantly improve the performance of the UAV-assisted wireless energy transmission communication network.

Precise minimally invasive treatment of mandibular fracture in children assisted by digital surgery technology

Objective: To explore the role of digital three-dimensional printing technology and multifunctional board in the treatment of mandibular fracture in children. Methods: From January 2006 to January 2022, 42 children with mandibular fracture were treated by Department of Stomatology, in The First Affiliated Hospital of Bengbu Medical College, including 25 males and 17 females. The patients, aged from 4 to 12 years, with the median age was 10 years old, were divided into observation group (22 cases) and routine group (20 cases) according to the treatment methods. In the observation group, the multifunctional board was made before operation, and the CT data of the children were imported into Mimics software in".dicom"format, and the displaced mandible was virtually reset. The jaw reduction model was made by three-dimensional printing, and the surgical operation was simulated on the reduction model to determine the model and position of the internal fixation device and shape it. During the operation, the fracture was reduced and fixed according to the preoperative design; The conventional group was treated with open reduction and internal fixation of mandibular fracture by traditional methods, and the clinical application value was compared and analyzed through the intraoperative situation, occlusal relationship, and follow-up of the two groups. Results: The total intraoperative bleeding volume [(30.25±4.02) ml] and surgical time [(64.3±9.2) min] in the observation group were significantly lower than those in the conventional group [(35.13±5.69) ml and (84.6±13.9) min, respectively] (F=6.18, P=0.003; F=1.32, P=0.001). The excellent and good rate of occlusal relationship in the observation group [96% (21/22)] was significantly higher than that in the conventional group [85% (17/20)] (F=4.27, P=0.039). The incidence of complications, the observation group, 1 case of poor occlusion, 1 case of postoperative infection; In the routine group, there were 3 cases with poor occlusion, 1 case with nerve injury, 1 case with root injury and 1 case with tooth germ injury. Conclusions: The application of digitization three-dimensional printing technology combined with multifunctional occlusal plate in children's mandibular fracture is minimally invasive, safe, efficient and accurate, and the clinical effect is good.

Risks that induce bicycle accidents: Measurement and analysis of bicyclist behavior while going straight and turning right using a bicycle simulator

In 2021, 69 % of those who died in Japan while riding a bicycle were of an older age. Preventing such accidents is an important issue because older bicyclists are more likely to be fatally injured in an accident. We developed a bicycle simulator that can safely simulate dangerous traffic environments by combining VR technology, motion capture technology, and various sensors to investigate the driving behavior of bicyclists who are involved in accidents. The simulator measures operating data such as floor reaction force, wheel rotation angle, brake lever displacement, position and posture of motion capture devices, and position and posture of the bicycle and vehicles at 60 Hz. We projected images of the virtual traffic environment to reflect the driving behavior in real-time onto three screens installed at the front, right side, and rear of the bicycle using three projectors. The constructed simulator was implemented for a “crossing inspection” where a rider checks for safety in front and behind while riding down a straight road with one lane and crossing this roadway and compared this to a “tracing inspection” where a model route is traced using a previously measured safe route taken by a younger rider. We measured and analyzed the bicyclist behaviors of nine younger and six older participants during two types of inspections as a usability study. In the crossing inspection, the crash rate for the older riders in the near lane was 5.3 times higher than that for the young. Riders collided with vehicles exhibited minimal rearward checking angles before entering a roadway, extended durations from the end of the last rearward check to roadway entry, and considerable standard deviations during road crossings. Moreover, in the tracing inspection, younger participants demonstrated superior trajectory passage rates and maintained closer proximity to the model, whereas older participants manifested diminished trajectory passage rates and remained at more extended distances from the model. Notably, a declining trajectory passage rate corresponded to an increase in the standard deviation of the crossing route and the time taken to enter the roadway.

In vitro and in silico assessment of flow modulation after deploying the Contour Neurovascular System in intracranial aneurysm models

BackgroundThe novel Contour Neurovascular System (Contour) has been reported to be efficient and safe for the treatment of intracranial, wide-necked bifurcation aneurysms. Flow in the aneurysm and posterior cerebral arteries...