Publications by authors named "Hiroshi Takemura"

Postural control is one of the primary body functions for fall prevention. Unexpected perturbation-based balance training is effective for improving postural control. However, the effect of perturbation-based training using assistive devices on muscle activity and co-contraction for standing balance is still unclear.

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In this study, we developed a rigid-scope system that can perform hyperspectral imaging (HSI) between visible and 1600 nm wavelengths using a supercontinuum light source and an acousto-optic tunable filter to emit specific wavelengths. The system optical performance was verified, and the classification ability was investigated. Consequently, it was demonstrated that HSI (490-1600 nm) could be performed.

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Article Synopsis
  • The article discusses a method for mobile robots to navigate through dense crowds by predicting where pedestrians will likely move in the future.
  • It uses a system that generates cost maps from these predicted trajectories, allowing the robot to navigate smoothly without constantly swerving.
  • Evaluation results indicate that this approach enables the robot to reach its destination 26.4% faster than traditional 2D path planning methods in simulations involving 50 pedestrians.
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Reactive postural control is an important component of the balance function for fall prevention. Perturbation-based balance exercises improve reactive postural control; however, these exercises require large, complex instruments and expert medical guidance. This study investigates the effects of unexpected perturbation-based balance exercises using a wearable balance exercise device (WBED) on reactive postural control.

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Significance: Determining the extent of gastric cancer (GC) is necessary for evaluating the gastrectomy margin for GC. Additionally, determining the extent of the GC that is not exposed to the mucosal surface remains difficult. However, near-infrared (NIR) can penetrate mucosal tissues highly efficiently.

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The insertion of conventional colonoscopes can sometimes cause patients to experience pain during the procedure owing to the stretching of the mesentery. In this study, a prototype of a robotic colonoscope with a double-balloon and double-bend tube based on the conventional double-balloon endoscope was developed to simplify insertion and prevent the overstretching of the colon. Both the outer and inner tubes were confirmed to be free from interference from wires and sheaths.

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  • Autism spectrum disorder (ASD) is a condition that makes it hard for some people to understand how others move and interact, which can lead to clumsiness when walking around others.
  • The study checked how 26 adults without a diagnosis but with some autistic traits see and react to life-sized moving avatars in videos, using a special questionnaire and brain activity measurements.
  • The results showed that those with more autistic traits reacted slower and less strongly to the approaching avatars, suggesting they might struggle more with noticing when someone is getting close in real life.
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Purpose: The authors have been using improved superelastic Nickel-Titanium alloy wire (ISW) to close and align extraction spaces simultaneously, instead of separately using rigid wires for closing extraction spaces and Ni-Ti alloy wires for leveling and aligning. ISW has a low stiffness, which makes it challenging to generate sufficient moments. This study aimed to demonstrate the forces and moments exerted on adjacent brackets using an orthodontic simulator (OSIM) attached to a high-precision 6-axis sensor.

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A markerless gait analysis system can measure useful gait metrics to determine effective clinical treatment. Although this gait analysis system does not require a large space, several markers, or time constraints, it inaccurately measure lower limb joint kinematics during gait. In particular, it has a substantial ankle joint angle error.

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Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by a combination of atypicalities in social cognition. Previous studies showed that people with autistic traits have atypicality in motion perception on a point-light display by measuring visual event-related potentials (ERPs). Although some studies have focused on the association between motion perception and autistic traits, visual ERPs to biological motion as large as actual person have not been investigated.

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Background: A previous study on 2-dimensional evaluation of the subtalar joint functioning in varus ankle osteoarthritis concluded that varus deformity was compensated for by the subtalar joint during early stages but not in the advanced stages. Although compensatory function is expected both along the axial and coronal planes, compensatory function in all 3 dimensions (3D) remains unevaluated. This study evaluated the 3D-compensatory function of a varus subtalar joint using Globally Optimal Iterative Closest Points (Go-ICP), a 3D-shape registration algorithm, after 3D-bone shape reconstruction using computed tomography.

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Background: Most orthodontic cases consist of varying degrees of crowding. To manage crowded dentitions, nickel-titanium archwires with various ligation methods are often used.

Objective: We aimed to investigate the effect of different ligation methods with respect to force and moment and suggest the efficient ligation method for treating rotation and displacement simultaneously.

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Carbon-fiber running-specific prostheses have enabled individuals with lower extremity amputation to run by providing a spring-like leg function in their affected limb. When individuals without amputation run at a constant speed on level ground, the net external mechanical work is zero at each step to maintain a symmetrical bouncing gait. Although the spring-like "bouncing step" using running-specific prostheses is considered a prerequisite for running, little is known about the underlying mechanisms for unilateral transfemoral amputees.

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A cost-effective gait analysis system without attachments and specialized large environments can provide useful information to determine effective treatment in clinical sites. This study investigates the capability of a single camera-based pose estimation system using OpenPose (OP) to measure the temporo-spatial and joint kinematics parameters during gait with orthosis. Eleven healthy adult males walked under different conditions of speed and foot progression angle (FPA).

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Article Synopsis
  • The mouse serves as an important animal model for understanding complex brain functions and testing new drugs.
  • A new simple and cost-effective method for 3D pose estimation using a single RGB-D camera has been developed, enhancing the accuracy of tracking various mouse body parts compared to previous methods.
  • This research aims to bridge the gap between subtle behavioral changes in mice and emotional responses, potentially advancing neuroscience and pharmaceutical developments.
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In this study, a laparoscopic imaging device and a light source able to select wavelengths by bandpass filters were developed to perform multispectral imaging (MSI) using over 1000 nm near-infrared (OTN-NIR) on regions under a laparoscope. Subsequently, MSI (wavelengths: 1000-1400 nm) was performed using the built device on nine live mice before and after tumor implantation. The normal and tumor pixels captured within the mice were used as teaching data sets, and the tumor-implanted mice data were classified using a neural network applied following a leave-one-out cross-validation procedure.

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Although weight transfer is an important component of gait rehabilitation, the biomechanical strategy underlying the vertical ground reaction force loading/unloading in individuals with unilateral transfemoral amputation between intact and prosthetic limbs remains unclear. We investigated weight transfer between limbs at different walking speeds in 15 individuals with unilateral transfemoral amputation and 15 individuals without amputation as controls, who walked on an instrumented treadmill. The normalized unloading and loading rates were calculated as the slope of decay and rise phase of the vertical ground reaction force, respectively.

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The diagnosis of gastrointestinal stromal tumor (GIST) using conventional endoscopy is difficult because submucosal tumor (SMT) lesions like GIST are covered by a mucosal layer. Near-infrared hyperspectral imaging (NIR-HSI) can obtain optical information from deep inside tissues. However, far less progress has been made in the development of techniques for distinguishing deep lesions like GIST.

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As a fundamental motor pattern, the ability to run at a range of constant speeds is a prerequisite for participating in competitive games and recreational sports. However, it remains unclear how unilateral transfemoral amputees modulate anterior and posterior ground reaction force impulses (GRFIs) in order to maintain constant running speeds. The purpose of this study was to investigate anterior and posterior GRFIs across a wide range of constant running speeds in unilateral transfemoral amputees wearing a running-specific prosthesis.

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During orthodontic treatment, plaque tends to form around fixed orthodontic appliances, which increases the risk of dental caries. It has been reported that ultarafine bubble with a diameter <1 μm water (UFBW) effectively removes organic matter. In addition, UFBW is harmless and stable for at least one month with refrigeration.

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A pulsed laser cause vaporization of tissue by plasma if a laser can provide high-density energy within a very short pulse duration. Such phenomena are called laser-induced plasma ablation. The influence of the laser-induced plasma ablation for tissue is unclear because the ablation mechanism is differing regardless of two lasers provide almost the same power density.

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Previous studies have shown that people with autistic traits have difficulties in motion perception, such as human gait as depicted on a point-light display. A recent study reported that adults with autism spectrum disorders showed atypical visual event-related evoked potentials (ERPs) in response to radial optic flow. To determine the correlation between gait perception and autistic traits in the general population, the present study recorded ERPs time-locked to the onset of approaching and receding point-light walkers.

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A lot of elderly people need to care for joint disease, and one of the treatments for ankle osteoarthritis is artificial joint replacement surgery. Estimating the relative positional difference (alignment) between the bone before the deformation and the deformed bone, artificial joint replacement surgery can be performed precisely. By using the estimated alignment, the artificial ankle joint can obtain high satisfaction with less pain and enough function as an alternative.

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