Award type：Award from international society, conference, symposium, etc.  Country：Korea, Republic of

Award type：Award from Japanese society, conference, symposium, etc.  Country：Japan

長谷川泰久先生は，人の上肢／下肢の運動支援，遠隔操作，医療支援ロボットなど，人の活動を支援するロボットに関する多大な研究業績によるロボメカ部門の学術発展への貢献，長年にわたるロボメカ部門運営への貢献が高く評価されています． 日本機械学会では，2021年にロボティクス・メカトロニクス部門長を務められるなど，学会，部門運営に大きく貢献されています．

Award type：Honored in official journal of a scientific society, scientific journal  Country：Japan

ROBOMECH Journal に掲載された優秀な論文の著者全員．

Award type：Award from Japanese society, conference, symposium, etc.  Country：Japan

Award type：Award from international society, conference, symposium, etc.  Country：Japan

Award type：Award from international society, conference, symposium, etc.  Country：Japan

Award type：Award from Japanese society, conference, symposium, etc.  Country：Japan

Award type：Award from Japanese society, conference, symposium, etc.  Country：Japan

Award type：Award from Japanese society, conference, symposium, etc.  Country：Japan

Award type：Award from Japanese society, conference, symposium, etc.  Country：Japan

Award type：Award from Japanese society, conference, symposium, etc.  Country：Japan

Country：Japan

Award type：Award from Japanese society, conference, symposium, etc.  Country：Japan

Award type：Honored in official journal of a scientific society, scientific journal  Country：Japan

Award type：Award from international society, conference, symposium, etc.  Country：Japan

Award type：Award from Japanese society, conference, symposium, etc.  Country：Japan

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Award type：Award from Japanese society, conference, symposium, etc.  Country：Japan

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Award type：Award from international society, conference, symposium, etc.  Country：Japan

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Award type：Award from Japanese society, conference, symposium, etc.  Country：Japan

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Award type：Award from international society, conference, symposium, etc. 

Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEEE Robotics and Automation Letters  

This study proposed an innovative teleoperation system utilizing video conferencing applications to enhance availability and operability in mobile networks. The proposed system accomplished this by transmitting video through screen sharing and embedding control signals into audio signals by converting them into sine waves whose amplitudes correspond to control values. Compared with conventional VPN-based approaches, our approach reduced communication delay over mobile data networks by more than 1 s and, in evaluation experiments using Toyota's Human Support Robot, demonstrated improved operational accuracy. The proposed method expanded the operational range beyond Wi-Fi or cable limitations, enabling outdoor remote control via mobile data communication. This advancement opens new possibilities in hazardous environment operations, elderly care, and data collection for AI model training. Our approach improved the flexibility of teleoperation systems, paving the way for widespread adoption across various industries and research domains. Future improvements in video conferencing applications and next-generation mobile networks could further enhance system performance.

DOI： 10.1109/LRA.2025.3544092

Open Access

Scopus

Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： doi: 10.1109/TOH.2024.3522897

Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/LRA.2024.3521682

Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.1002/rcs.70019

Language：English   Publishing type：Research paper (scientific journal)  

Many haptic guidance systems have been studied over the years; however, most of them have been limited to predefined guidance methods. Calculating guidance according to the operator's motion is important for efficient human motor adaptation and learning. In this study, we developed a system that haptically provides guidance trajectory by sequential weighting between the operator's trajectory and the ideal trajectory calculated from a predictive-vision system. We investigated whether motion completion with a predictive-vision system affects human motor accuracy and adaptation in time-constrained goal-directed reaching and ball-hitting tasks through subject experiments. The experiment was conducted with 12 healthy participants, and all participants performed ball-hitting tasks. Half of the participants get forceful guidance from the proposed system in the middle of the experiment. We found that the use of the proposed system improved the operator's motor performance. Furthermore, we observed a trend in which the improvement in motor performance using this system correlated with that after the washout of this system. These results suggest that the predictive-vision system effectively enhances motor accuracy to the target error in dynamic and time-constrained reaching and hitting tasks and may contribute to facilitating motor learning.

DOI： 10.1038/s41598-024-52811-z

Open Access

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：International Journal of Medical Robotics and Computer Assisted Surgery  

Background: Robot-assisted systems have predominantly relied on teleoperation, where visual feedback is the primary source of information. However, advances in tactile sensing and displays offer new opportunities to enhance surgical transparency, efficiency, and safety. Methods: A PRISMA-guided search was conducted across PubMed, IEEE Xplore, Scopus, and Web of Science databases to identify relevant studies. Results: Out of 645 screened articles, 98 met the inclusion criteria, and 33 were included in the final review. The review discusses various tactile feedback stimulus types, applications, and challenges in the context of robot-assisted minimally invasive surgery. Conclusion: While kinaesthetic feedback has been extensively explored to restore the natural interaction between the surgeon and the surgical environment, tactile feedback remains largely confined to research settings. This is due to significant challenges in integrating tactile feedback into robotic systems and current limitations of sensing technologies.

DOI： 10.1002/rcs.70019

Scopus

Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.1016/j.softx.2024.101979

Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/LRA.2024.3495591

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Robotics  

Force-feedback devices enhance task performance in most robot teleoperations. However, their increased size with additional degrees of freedom can limit the robot’s applicability. To address this, an interface that visually presents force feedback is proposed, eliminating the need for bulky physical devices. Our telepresence system renders robotic hands transparent in the camera image while displaying virtual hands. The forces applied to the robot deform these virtual hands. The deformation creates an illusion that the operator’s hands are deforming, thus providing pseudo-haptic feedback. We conducted a weight comparison experiment in a virtual reality environment to evaluate force sensitivity. In addition, we conducted an object touch experiment to assess the speed of contact detection in a robot teleoperation setting. The results demonstrate that our method significantly surpasses conventional pseudo-haptic feedback in conveying force differences. Operators detected object touch 24.7% faster using virtual hand deformation compared to conditions without feedback. This matches the response times of physical force-feedback devices. This interface not only increases the operator’s force sensitivity but also matches the performance of conventional force-feedback devices without physically constraining the operator. Therefore, the interface enhances both task performance and the experience of teleoperation.

DOI： 10.3390/robotics13100143

Open Access

Scopus

Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.3390/robotics13100143

DOI： https://doi.org/10.3390/robotics13100143

Other Link： https://www.mdpi.com/2218-6581/13/10/143

Authorship：Last author   Language：English  

DOI： https://doi.org/10.3390/s24186050

DOI： https://doi.org/10.3390/s24186050

Other Link： https://www.mdpi.com/1424-8220/24/18/6050

Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/LRA.2024.3461550

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Sensors  

Template matching is a common approach in bin-picking tasks. However, it often struggles in complex environments, such as those with different object poses, various background appearances, and varying lighting conditions, due to the limited feature representation of a single template. Additionally, during the bin-picking process, the template needs to be frequently updated to maintain detection performance, and finding an adaptive template from a vast dataset poses another challenge. To address these challenges, we propose a novel template searching method in a latent space trained by a Variational Auto-Encoder (VAE), which generates an adaptive template dynamically based on the current environment. The proposed method was evaluated experimentally under various conditions, and in all scenarios, it successfully completed the tasks, demonstrating its effectiveness and robustness for bin-picking applications. Furthermore, we integrated our proposed method with YOLO, and the experimental results indicate that our method effectively improves YOLO’s detection performance.

DOI： 10.3390/s24186050

Open Access

Scopus

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/LRA.2024.3415931

Scopus

Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.1080/01691864.2024.2376024

Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/ACCESS.2024.3418206

Language：English   Publishing type：Research paper (scientific journal)  

In the context of medical imaging and machine learning, one of the most pressing challenges is the effective adaptation of pre-trained models to specialized medical contexts. Despite the availability of advanced pre-trained models, their direct application to the highly specialized and diverse field of medical imaging often falls short due to the unique characteristics of medical data. This study provides a comprehensive analysis on the performance of various fine-tuning methods applied to pre-trained models across a spectrum of medical imaging domains, including X-ray, MRI, Histology, Dermoscopy, and Endoscopic surgery. We evaluated eight fine-tuning strategies, including standard techniques such as fine-tuning all layers or fine-tuning only the classifier layers, alongside methods such as gradually unfreezing layers, regularization based fine-tuning and adaptive learning rates. We selected three well-established CNN architectures (ResNet-50, DenseNet-121, and VGG-19) to cover a range of learning and feature extraction scenarios. Although our results indicate that the efficacy of these fine-tuning methods significantly varies depending on both the architecture and the medical imaging type, strategies such as combining Linear Probing with Full Fine-tuning resulted in notable improvements in over 50% of the evaluated cases, demonstrating general effectiveness across medical domains. Moreover, Auto-RGN, which dynamically adjusts learning rates, led to performance enhancements of up to 11% for specific modalities. Additionally, the DenseNet architecture showed more pronounced benefits from alternative fine-tuning approaches compared to traditional full fine-tuning. This work not only provides valuable insights for optimizing pre-trained models in medical image analysis but also suggests the potential for future research into more advanced architectures and fine-tuning methods.

DOI： 10.1016/j.imavis.2024.105012

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DOI： https://doi.org/10.1093/jcde/qwae047

Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s11548-024-03101-6

Language：English   Publishing type：Research paper (scientific journal)  

Robotic exoskeletons, which assist in stand-to-kneel and kneel-to-stand (STK-KTS) movements and static kneeling postures are in great demand in the nursing field. This movement involves continuous adjustment of the center of gravity without a sufficient support polygon, which enhances the required joint effort of the ankle and knee. This study proposes a novel passive lower limb exoskeleton to support the movement. The exoskeleton was attached to the right leg and comprised a gas spring. The design followed an assistive strategy of the expanded support polygon. During the STK-KTS, the gas spring provided extra contact with the ground, thereby expanding the support polygon to increase motion stability and propping the knee to provide torque to the leg. The effectiveness of the gas spring was analyzed using a Lagrange dynamics-based simulation. Moreover, it was confirmed that the support polygon was expanded due to the proposed exoskeleton in real-world experiments. Further, experiments with seven healthy subjects showed that the exoskeleton reduced the time-integrated myoelectric potentials of the legs during STK-KTS (13.6%) and static posture (37.9%). These results imply that the proposed exoskeleton has the potential to reduce physical loads and provide a comfortable working environment for nursing workers.

DOI： 10.1109/TMECH.2023.3294255

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1080/01691864.2024.2324303

Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.1038/s41598-024-52811-z

Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.3390/s24020711

DOI： https://doi.org/10.3390/s24020711

Other Link： https://www.mdpi.com/1424-8220/24/2/711

Language：English   Publishing type：Research paper (scientific journal)  

Wearable robotic limbs support sit-to-stand (STS) transfer with increased stability while maintaining a compact size, as well as providing body weight support. This paper proposes a new robotic limb, Variable Grounding Flexible Limb (VGFL). The VGFL achieved a novel strategy in which its grounding point tracks the forward shift of the wearer's center of gravity (CoG) during STS. Since the strategy keeps the distance between the grounding point and the CoG close, an upward force can efficiently work for the STS assistance. To implement the strategy, this paper utilized the High-Strength and Flexible Mechanism (HSFM). The HSFM can change its grounding point while being capable of lifting body weight with one motor. Owing to these unique characteristics, the VGFL can realize the strategy without multiple actuators and complex controllers. Furthermore, real-world experiments confirmed that the grounding point of the VGFL accurately tracked the forward shift of the CoG during the STS assistance. Moreover, experiments conducted with three healthy subjects showed that the VGFL reduced the surface myoelectricity of the lower limbs during STS transfer. The VGFL could demonstrate high support performance in STS with the CoG tracking strategy.

DOI： 10.1109/LRA.2023.3328449

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.1109/ACCESS.2023.3349169

DOI： 10.1109/ACCESS.2023.3349169

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Other Link： https://ieeexplore.ieee.org/abstract/document/10379610

Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEEE Robotics and Automation Letters  

This letter presents a novel approach to fabric manipulation through the development and optimization of a single-actuator-driven roller gripper. Focused on addressing the challenges inherent in handling fabrics with diverse thicknesses and materials, our gripper employs a passive adaptable mechanism driven by springs, enabling effective manipulation of fabrics ranging from 0.1 mm to 2.25 mm in thickness. We analyze gripper-fabric interaction forces to identify the parameters that influence successful grasping. We then optimize the gripper's normal forces and the roller's tangential force using the proposed model. Systematic evaluations demonstrated the gripper's capability to separate individual layers from fabric stacks, achieving a 94.9% success rate across multiple fabric types. Overall, this research offers a compact, cost-effective solution with broad applicability in diverse industrial automation contexts, providing valuable insights for advancing robotic fabric handling systems.

DOI： 10.1109/LRA.2024.3461550

Open Access

Scopus

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/CBS61689.2024.10860490

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEEE Robotics and Automation Letters  

Intuitive teleoperation enables operators to embody remote robots, providing the sensation that the robot is part of their own body during control. The sense of agency (SoA), i.e., the feeling of controlling the robot, contributes to enhanced motivation and embodiment during teleoperation. However, the SoA can be diminished by time-varying communication delays associated with teleoperation. We propose a visual guidance system to assist operations while maintaining a high SoA when teleoperating robots with time-varying delays, thereby improving positioning accuracy. In the proposed system, a recurrent neural network (RNN) model, trained on the pouring tasks of skilled operators, predicts the input position 500 ms ahead of the input from the novice operator and visually presents it in real-time as the end-effector target position. Experiments with time-varying delays confirmed that the proposed method provides a visual representation of the target position interpolated in time and space from the real-time input of the operator, guiding the operator to align with the trajectory of the skilled operator. The proposed method significantly improves task performance even under time-varying delays while maintaining a high SoA compared with other conditions. Applying the prediction system developed in this study to human-robot collaborative control may enable interventions that maintain the SoA.

DOI： 10.1109/LRA.2024.3495591

Scopus

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/AIM55361.2024.10637238

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Language：English   Publishing type：Research paper (scientific journal)  

In recent years, many countries, including Japan, have rapidly aging populations, making the preservation of seniors' quality of life a significant concern. For elderly people with impaired physical abilities, support for toileting is one of the most important issues. This paper details the design, development, experimental assessment, and potential application of the gripper system, with a focus on the unique requirements and obstacles involved in aiding elderly or hemiplegic individuals in dressing and undressing trousers. The gripper we propose seeks to find the right balance between compliance and grasping forces, ensuring precise manipulation while maintaining a safe and compliant interaction with the users. The gripper's integration into a custom-built robotic manipulator system provides a comprehensive solution for assisting hemiplegic individuals in their dressing and undressing tasks. Experimental evaluations and comparisons with existing studies demonstrate the gripper's ability to successfully assist in both dressing and dressing of trousers in confined spaces with a high success rate. This research contributes to the advancement of assistive robotics, empowering elderly, and physically impaired individuals to maintain their independence and improve their quality of life.

DOI： 10.1080/01691864.2024.2376024

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Authorship：Last author   Language：English  

DOI： https://doi.org/10.3390/s23249865

DOI： https://doi.org/10.3390/s23249865

Other Link： https://www.mdpi.com/1424-8220/23/24/9865

Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGERNATURE  

Wearable body weight support systems can assist individuals with mobility impairments in performing daily living activities with greater ease and independence. However, existing systems have limitations in terms of balancing their strength, compact size, interaction with the ground, and driving. In this paper, we present the High-Strength and Flexible Mechanism (HSFM) designed for body weight support. The HSFM utilizes a coiling truss mechanism to perform flexible transformation between a straight and spiral shape. Its complex linkages create the mechanical constraints of the structure and enhance its stiffness. Additionally, the HSFM achieved a high extension rate, effective wire-driven mechanism, and smooth shift of the grounding point. We provide a detailed description of the HSFM, including the simplest 4-linkage mechanism, its mechanical constraints, and the wire-driven mechanism. Moreover, we conducted parametric analysis and geometric calculation on the link structure. The results justified the mechanical constraints of the HSFM and ensured the high extension rate. Further, its functionality for body weight support was evaluated with the hardware and showed sufficient results in terms of strength, smooth grounding, and wire-driven. This novel mechanism has the potential to develop a wearable body weight support robot enhancing daily living activities such as sit-to-stand transfer and walking.

DOI： 10.1186/s40648-023-00255-x

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Web of Science

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Language：English   Publishing type：Research paper (scientific journal)  

Robotic teleoperation is highly valued for its ability to remotely execute tasks that demand sophisticated human decision-making or that are intended to be carried out by human operators from a distance. However, when using the internet as a communication framework for teleoperation, high latency, and fluctuations make accurate positioning and time-dependent tasks difficult. To mitigate the negative effects of time delay, this paper proposes a teleoperation system that uses cross reality (XR) as a predictive display of the outcome of operators’ intended actions and develops a time-delay aware shared control to fulfill the intention. The system targets a liquid pouring task, wherein a white ring that indicates the intended height of the liquid surface is overlayed onto the beaker in a delayed camera image to close the visual feedback loop on the leader side. Simultaneously, the shared control automatically completes the pouring action to track the intended liquid height. The performance of the proposed system is validated based on liquid pouring experiments performed by human subjects. When compared with direct control, the absolute error rate decreased significantly for a constant round-trip time delay of 0.8 s and 1.2 s, similarly for a time-varying delay of 0.4 s and 0.8 s. Moreover, when the time-varying delay was 0.8 s, operators achieved significantly higher accuracy while maintaining comparable operation time. These results indicate that our proposed system improves operability even in the presence of time-varying delays in communication networks.

DOI： 10.1186/s40648-023-00258-8

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Sensors  

In the context of Minimally Invasive Surgery, surgeons mainly rely on visual feedback during medical operations. In common procedures such as tissue resection, the automation of endoscopic control is crucial yet challenging, particularly due to the interactive dynamics of multi-agent operations and the necessity for real-time adaptation. This paper introduces a novel framework that unites a Hierarchical Quadratic Programming controller with an advanced interactive perception module. This integration addresses the need for adaptive visual field control and robust tool tracking in the operating scene, ensuring that surgeons and assistants have optimal viewpoint throughout the surgical task. The proposed framework handles multiple objectives within predefined thresholds, ensuring efficient tracking even amidst changes in operating backgrounds, varying lighting conditions, and partial occlusions. Empirical validations in scenarios involving single, double, and quadruple tool tracking during tissue resection tasks have underscored the system’s robustness and adaptability. The positive feedback from user studies, coupled with the low cognitive and physical strain reported by surgeons and assistants, highlight the system’s potential for real-world application.

DOI： 10.3390/s23249865

Open Access

Scopus

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/aisy.202300152

Open Access

Scopus

Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

The growing need for high levels of autonomy in Autonomous Robotic Surgery Systems (ARSS) calls for innovative approaches to reduce surgeons' cognitive load, optimize hospital workflows, and ensure efficient task-level reasoning and adaptation during execution. This paper presents a novel hybrid framework that synergistically combines Task-Motion Planning and Dynamic Behavior Trees for ARSS in Minimally Invasive Surgery. Our approach is designed to address the challenges of coordinating multiple surgical tools within a small workspace, thereby making complex surgical tasks like multi-throw suturing feasible and efficient. Through an extensive evaluation in simulation across diverse initial conditions and noise scenarios, the proposed method demonstrates improved success rates, reduced execution times, and fewer regrasps compared to standalone approaches. Furthermore, it showcases robustness under increased noise conditions. By applying our framework to a complex multi-throw suturing task, we illustrate its capability to seamlessly handle comprehensive suturing tasks, including needle picking, insertion, extraction, and the handover of the needle between Patient Side Manipulators. The results suggest that our hybrid approach not only enhances ARSS autonomy but also adapts effectively to unexpected environmental changes, laying the groundwork for its potential applicability in real-world surgical robotics.

DOI： 10.1109/ACCESS.2023.3308619

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEEE Access  

Remote teleoperation has shown significant advancements since the first teleoperation system was proposed by Goertz in the 1940s. In recent years, the research on shared control methodologies in which the robot assists the operators in accomplishing the desired tasks has gained extensive attention. One such important task in teleoperation is object grasping. In this paper, we propose a shared control framework to enhance the teleoperated grasping performance. The proposed framework is built upon a virtual reality device-based direct teleoperation system. In this framework, a template matching-based object point cloud compensation is introduced for multi-angle grasping pose generation. Then, the feasible grasping candidates are selected considering joint constraints-aware manipulability. Finally, the grasping assistance is achieved by trajectory blending with dynamic authority adjustment. To validate the performance of the proposed framework, we carried out experimental evaluations. The output results indicate improved grasping performance in terms of reduced task completion time, linear trajectory, and workload.

DOI： 10.1109/ACCESS.2023.3292410

Scopus

Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEEE Journal of Biomedical and Health Informatics  

Objective: While neuroscience research has established a link between vision and intention, studies on gaze data features for intention recognition are absent. The majority of existing gaze-based intention recognition approaches are based on deliberate long-term fixation and suffer from insufficient accuracy. In order to address the lack of features and insufficient accuracy in previous studies, the primary objective of this study is to suppress noise from human gaze data and extract useful features for recognizing grasp intention. Methods: We conduct gaze movement evaluation experiments to investigate the characteristics of gaze motion. The target-attracted gaze movement model (TAGMM) is proposed as a quantitative description of gaze movement based on the findings. A Kalman filter (KF) is used to reduce the noise in the gaze data based on TAGMM. We conduct gaze-based natural grasp intention recognition evaluation experiments to collect the subject's gaze data. Four types of features describing gaze point dispersion (f_{var}), gaze point movement (f_{gm}), head movement (f_{hm}), and distance from the gaze points to objects (f_{d_{j}}) are then proposed to recognize the subject's grasp intentions. With the proposed features, we perform intention recognition experiments, employing various classifiers, and the results are compared with different methods. Results: The statistical analysis reveals that the proposed features differ significantly across intentions, offering the possibility of employing these features to recognize grasp intentions. We demonstrated the intention recognition performance utilizing the TAGMM and the proposed features in within-subject and cross-subject experiments. The results indicate that the proposed method can recognize the intention with accuracy improvements of 44.26% (within-subject) and 30.67% (cross-subject) over the fixation-based method. The proposed method also consumes less time (34.87 ms) to recognize the intention than the fixation-based method (about 1 s). Conclusion: This work introduces a novel TAGMM for modeling gaze movement and a variety of practical features for recognizing grasp intentions. Experiments confirm the effectiveness of our approach. Significance: The proposed TAGMM is capable of modeling gaze movements and can be utilized to process gaze data, and the proposed features can reveal the user's intentions. These results contribute to the development of gaze-based human-robot interaction.

DOI： 10.1109/JBHI.2023.3238406

Scopus

Authorship：Last author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Robotics Society of Japan  

<p>The microinjection technique is widely applied in fields such as biology, medicine, and intracytoplasmic sperm injection (ICSI). Microinjection process requires special skill and, thus, generally ICSI is conducted by embryologists. However, the shortage of embryologists has become a problem in clinics, and there is a need for an easy injection system that does not rely on embryologists. In this study, we propose a micromanipulation interface that assists to perceive cell extension for easy injection system. The proposed interface provides 2-dimensional force/tactile feedback through a fabric actuator with air pressure based on real-time visual sensing of cell deformation. The effectiveness of the proposed interface is verified through puncturing experiments on perceiving cell extension perfumed by inexperienced subjects. </p>

DOI： 10.7210/jrsj.41.322

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Language：English   Publishing type：Research paper (scientific journal)  

Minimally invasive surgery has undergone significant advancements in recent years, transforming various surgical procedures by minimizing patient trauma, postoperative pain, and recovery time. However, the use of robotic systems in minimally invasive surgery introduces significant challenges related to the control of the robot’s motion and the accuracy of its movements. In particular, the inverse kinematics (IK) problem is critical for robot-assisted minimally invasive surgery (RMIS), where satisfying the remote center of motion (RCM) constraint is essential to prevent tissue damage at the incision point. Several IK strategies have been proposed for RMIS, including classical inverse Jacobian IK and optimization-based approaches. However, these methods have limitations and perform differently depending on the kinematic configuration. To address these challenges, we propose a novel concurrent IK framework that combines the strengths of both approaches and explicitly incorporates RCM constraints and joint limits into the optimization process. In this paper, we present the design and implementation of concurrent inverse kinematics solvers, as well as experimental validation in both simulation and real-world scenarios. Concurrent IK solvers outperform single-method solvers, achieving a 100% solve rate and reducing the IK solving time by up to 85% for an endoscope positioning task and 37% for a tool pose control task. In particular, the combination of an iterative inverse Jacobian method with a hierarchical quadratic programming method showed the highest average solve rate and lowest computation time in real-world experiments. Our results demonstrate that concurrent IK solving provides a novel and effective solution to the constrained IK problem in RMIS applications.

DOI： 10.3390/s23063328

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Language：English   Publishing type：Research paper (scientific journal)  

Robot-assisted minimally invasive surgery (RMIS) has been shown to be effective in improving surgeon capabilities, providing magnified 3D vision, highly dexterous surgical tools, and intuitive human-robot interfaces for high-precision tool motion control. Robotic surgical tools (RST) are a critical component that defines the performance of an RMIS system. Current RSTs still represent a high cost, with few commercially available options, which limits general access and research on RMIS. We aim to take advantage of recent progress in biocompatible 3D printing and contribute to the development of RMIS technologies, presenting an open platform for low-cost, biocompatible, and customizable RSTs. The proposed design concept consists of a 3-DOF end-effector with a decoupled wrist mechanism, a tool interface module, and a tool drive unit. We validated our end-effector design using Finite Element Analysis (FEA) to confirm that stress generated by high grip forces is maintained below the material yield stress. Validation experiments showed that the proposed RST could provide up to 10N grip forces and up to 3N pulling forces. The proposed control framework exhibited a mean absolute positioning tracking error of approximately 0.1 rad. Finally, we also demonstrated the use of the proposed RST in two surgical training tasks: pick-and-place and stitching. The designs and software control framework are open-access and freely available for customization and fast development at https://github.com/jcolan/OpenRST.

DOI： 10.1109/ACCESS.2023.3236821

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.1109/ACCESS.2023.3264785

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.1109/ACCESS.2023.3271003

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DOI： 10.1109/TNSRE.2023.3314503

Open Access

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1186/s40648-022-00228-6

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

There is a growing need for robots that can be remotely controlled to perform tasks of one’s own choice. However, the SoA (Sense of Agency: the sense of recognizing that the motion of an observed object is caused by oneself) is reduced because the subject of the robot motion is identified as external due to shared control. To address this issue, we aimed to suppress the decline in SoA by presenting auditory feedback that aims to blur the distinction between self and others. We performed the tracking task in a virtual environment under four different auditory feedback conditions, with varying levels of automation to manipulate the virtual robot gripper. Experimental results showed that the proposed auditory feedback suppressed the decrease in the SoA at a medium level of automation. It is suggested that our proposed auditory feedback could blur the distinction between self and others, and that the operator attributes the subject of the motion of the manipulated object to himself.

DOI： 10.3390/s22249779

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DOI： 10.3390/surgeries3040036

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DOI： DOI 10.1109/TNSRE.2022.3213823

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.3390/mi13101725

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.3390/s22197198

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.3390/s22166309

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Promising treatments for upper motor neuron disease are emerging in which motor function is restored by brain–computer interfaces and functional electrical stimulation. At present, such technologies and procedures are not applicable to lower motor neuron disease. We propose a novel therapeutic strategy for lower motor neuron disease and injury integrating neural stem cell transplantation with our new functional electrical stimulation control system. In a rat sciatic nerve transection model, we transplanted embryonic spinal neural stem cells into the distal stump of the peripheral nerve to reinnervate denervated muscle, and subsequently demonstrated that highly responsive limb movement similar to that of a healthy limb could be attained with a wirelessly powered two-channel neurostimulator that we developed. This unique technology, which can reinnervate and precisely move previously denervated muscles that were unresponsive to electrical stimulation, contributes to improving the condition of patients suffering from intractable diseases of paralysis and traumatic injury.

DOI： 10.3390/ijms23158760

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DOI： https://doi.org/10.1186/s40648-022-00228-6

Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/TMRB.2022.3176100

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/TMECH.2021.3068138

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEEE Transactions on Neural Systems and Rehabilitation Engineering  

Gait analysis and evaluation are vital for disease diagnosis and rehabilitation. Current gait analysis technologies require wearable devices or high-resolution vision systems within a limited usage space. To facilitate gait analysis and quantitative walking-ability evaluation in daily environments without using wearable devices, a mobile gait analysis and evaluation system is proposed based on a cane robot. Two laser range finders (LRFs) are mounted to obtain the leg motion data. An effective high-dimensional Takagi-Sugeno-Kang (HTSK) fuzzy system, which is suitable for high-dimensional data by solving the saturation problem caused by softmax function in defuzzification, is proposed to recognize the walking states using only the motion data acquired from LRFs. The gait spatial-temporal parameters are then extracted based on the gait cycle segmented by different walking states. Besides, a quantitative walking-ability evaluation index is proposed in terms of the conventional Tinetti scale. The plantar pressure sensing system records the walking states to label training data sets. Experiments were conducted with seven healthy subjects and four patients. Compared with five classical classification algorithms, the proposed method achieves the average accuracy rate of 96.57%, which is improved more than 10%, compared with conventional Takagi-Sugeno-Kang (TSK) fuzzy system. Compared with the gait parameters extracted by the motion capture system OptiTrack, the average errors of step length and gait cycle are only 0.02 m and 1.23 s, respectively. The comparison between the evaluation results of the robot system and the scores given by the physician also validates that the proposed method can effectively evaluate the walking ability.

DOI： 10.1109/TNSRE.2022.3213823

Open Access

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEEE Transactions on Medical Robotics and Bionics  

Wearable robots have become a prevalent method in the field of human augmentation and medical rehabilitation. Typical wearable robots mainly include exoskeletons and prostheses. However, their functions are limited due to dedicated design. In recent years, Supernumerary Robotic Limbs (SRLs) have become a hot spot in the field of wearable robots. Different from exoskeletons and prostheses, SRLs compensate and strengthen human abilities by providing extra limbs. This advantage allows SRLs to assist users in a novel way, rather than substituting missing limbs or enhancing existing limbs. However, finding a trade-off between wearability, efficiency, and usability of those SRLs is still an issue. This paper presents the state of the art in SRLs and discusses some open questions about SRLs’ design and control for further research. This review covers the following areas: (1) Basic concepts and classifications of SRLs; (2) The literature retrieval methodology; (3) Design functions of different types of SRLs, including their positive and negative aspects; (4) Different control strategies of SRLs, including positive and negative aspects, and some improvement methods in applying SRLs; (5) The impact on human body schema while using SRLs; (6) Open challenges and suggestions for future development. This review will help researchers understand the current state of SRLs and provide comprehensive knowledge foundations for them.

DOI： 10.1109/TMRB.2021.3086016

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.3390/mi12040379

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Language：English   Publishing type：Research paper (scientific journal)  

The microinjection technique, in which DNA is injected into cells, is widely applied in fields such as biology, medicine, and pharmacy. However, the implementation of the microinjection process requires skill and, thus, it is necessary to improve the operability. To this end, this study proposes a microinjection system that improves depth visibility through real-time 3D image presentation. An algorithm to estimate 3D position and size of micro-targets using a focal position adjustment mechanism is implemented to the system. In addition, a calibration method to adjust relative position and orientation between a target object and micromanipulators is developed. Then, the system presents reconstructed 3D images of a target and micromanipulators. Finally, the effectiveness of the proposed system is verified through manipulation experiments involving porcine embryos.

DOI： 10.1109/LRA.2021.3067857

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：(一社)日本手外科学会  

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Robotics  

The reduced workspace in endonasal endoscopic surgery (EES) hinders the execution of complex surgical tasks such as suturing. Typically, surgeons need to manipulate non-dexterous long surgical instruments with an endoscopic view that makes it difficult to estimate the distances and angles required for precise suturing motion. Recently, robot-assisted surgical systems have been used in laparoscopic surgery with promising results. Although robotic systems can provide enhanced dexterity, robot-assisted suturing is still highly challenging. In this paper, we propose a robot-assisted stitching method based on an online optimization-based trajectory generation for curved needle stitching and a constrained motion planning framework to ensure safe surgical instrument motion. The needle trajectory is generated online by using a sequential convex optimization algorithm subject to stitching kinematic constraints. The constrained motion planner is designed to reduce surrounding damages to the nasal cavity by setting a remote center of motion over the nostril. A dual concurrent inverse kinematics (IK) solver is proposed to achieve convergence of the solution and optimal time execution, in which two constrained IK methods are performed simultaneously; a task-priority based IK and a nonlinear optimization-based IK. We evaluate the performance of the proposed method in a stitching experiment with our surgical robotic system in a robot-assisted mode and an autonomous mode in comparison to the use of a conventional surgical tool. Our results demonstrate a noticeable improvement in the stitching success ratio in the robot-assisted mode and the shortest completion time for the autonomous mode. In addition, the force interaction with the tissue was highly reduced when using the robotic system.

DOI： 10.3390/robotics10010027

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Robotics Society of Japan  

<p>This study proposes a micromanipulation system that improves depth visibility through real-time 3D image presentation. A calibration method to adjust relative position and orientation between a target object and micromanipulators is implemented to the system; then the system presents reconstructed 3D images of a target and micromanipulators. The effectiveness of the proposed system is demonstrated through manipulation of an embryo. </p>

DOI： 10.7210/jrsj.39.467

CiNii Research

Authorship：Last author   Language：English   Publishing type：Research paper (international conference proceedings)  

In this paper, we present a mechanism that can facilitate soft actuator position control, bidirectional actuation, and getting rid of tether/hose. We proposed a simplistic piston pump as a source of actuation fluid for driving fluidic soft actuators instead of the traditional compressor-based approach to establish an expeditious position control for soft actuators. We explored the conceptual design of a bi-directional soft actuator and the piston pump thoroughly and calculated design and operating parameters. Further, deriving the mathematical model for the proposed system in terms of the position of the piston inside the piston pump and the angular position of the soft actuator. Subsequently, we discuss potential applications of the proposed mechanism.

DOI： 10.1109/MHS53471.2021.9767140

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In this study, new artificial dura-mater models were developed using a multilayered structure of a rubber material (represent an elastic component of a dura-mater) and a fiber sheet (represent fiber component of a dura-mater). The artificial dura-mater models were prepared for use in a brain surgery simulator, especially for transnasal pituitary surgery. The mechanical characteristics of the artificial dura-mater models were tested to check the similarities with porcine dura-mater. Tensile stress, viscoelasticity, and the cutting force generated by microscissors were tested to evaluate the fabricated models. Neurosurgeons also assessed the dura-mater models to evaluate their characteristics. The results indicate that these models made of two different non-woven fiber sheets emulated accurately the actual dura-mater.

DOI： 10.3390/app10249000

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DOI： 10.1186/s40648-020-00169-y

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1080/01691864.2020.1844797

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Language：English   Publishing type：Research paper (scientific journal)  

This paper presents our development of an intuitive teleoperation system for Toyota's Human Support Robot. While this robot has been widely used as an autonomous agent in the field of service robotics, we explore a possibility of this robot for the use of remote assistance of daily activities in home environments. For rapid prototyping an affordable teleoperation system, we adopt a commercially available VR device as a user interface and develop a Robot Operating System (ROS)-based control framework building on the software application programming interfaces (APIs). In particular, we implement a singularity robust inverse kinematics algorithm to achieve a coordinated whole-body motion of the robot for safe and intuitive operation. We empirically evaluate the practical feasibility of the proposed teleoperation system through various test tasks. We discuss the potential and limitations of the current development for its future improvement.

DOI： 10.1080/01691864.2020.1813623

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In this study, we developed a procedure for assembling hepatic microstructures into tube shapes using magnetic self-assembly for in vitro 3D micro-tissue fabrication. To this end, biocompatible hydrogels, which have a toroidal shape, were made using the micro-patterned electrodeposition method. Ferrite particles were used to coat the fabricated toroidal hydrogel microcapsules using a poly-L-lysine membrane. The microcapsules were then magnetized with a 3 T magnetic field, and assembled using a magnetic self-assembly process. During electrodeposition, hepatic cells were trapped inside the microcapsules, and they were cultured to construct tissue-like structures. The magnetized toroidal microstructures then automatically assembled to form tube structures. Shaking was used to enhance the assembly process, and the shaking speed was experimentally optimized to achieve the high-speed assembly of longer tube structures. The flow velocity inside the dish during shaking was measured by particle image velocimetry. Hepatic functions were evaluated to check for side-effects of the magnetized ferrite particles on the microstructures. Collectively, our findings indicated that the developed method can achieve the high-speed assembly of a large number of microstructures to form tissue-like hepatic structures.

DOI： 10.1088/1748-605X/ab8487

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In pneumatic muscle actuators (PMAs)-driven robotic applications, there might exist unpredictable shocks which lead to the sudden change of desired trajectories and large tracking errors. This is dangerous for physical systems. In this article, we propose a novel adaptive proxy-based robust controller (APRC) for PMAs, which is effective in realizing a damped response and regulating the behaviors of the PMA via a virtual proxy. Moreover, the integration of the APRC and the nonlinear disturbance observer further handles the system uncertainties/disturbances and improves the system robustness. According to the Lyapunov theorem, the tracking states of the closed-loop PMA control system are proven to be globally uniformly ultimately bounded through two motion phases. Extensive experiments are conducted to verify the superior performance of our approach, in multiple tracking scenarios.

DOI： 10.1109/TMECH.2020.2997041

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Endoscopic endonasal surgery (EES) is a minimally invasive technique for removal of pituitary adenomas or cysts at the skull base. This approach can reduce the invasiveness and recovery time compared to traditional open surgery techniques. However, it represents challenges to surgeons because of the constrained workspace imposed by the nasal cavity and the lack of dexterity with conventional surgical instruments. While robotic surgical systems have been previously proposed for EES, issues concerned with proper interface design still remain. In this paper, we present a cooperative, compact, and versatile bimanual human-robot interface aimed to provide intuitive and safe operation in robot-assisted EES. The proposed interface is attached to a robot arm and holds a multi-degree-of-freedom (DOF) articulated forceps. In order to design the required functionalities in EES, we consider a simplified surgical task scenario, with four basic instrument operations such as positioning, insertion, manipulation, and extraction. The proposed cooperative strategy is based on the combination of force based robot control for tool positioning, a virtual remote-center-of-motion (VRCM) during insertion/extraction tasks, and the use of a serial-link interface for precise and simultaneous control of the position and the orientation of the forceps tip. Virtual workspace constraints and motion scaling are added to provide safe and smooth control of our robotic surgical system. We evaluate the performance and usability of our system considering reachability, object manipulability, and surgical dexterity in an anatomically realistic human head phantom compared to the use of conventional surgical instruments. The results demonstrate that the proposed system can improve the precision, smoothness and safety of the forceps operation during an EES.

DOI： 10.3390/app10144809

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DOI： 10.3390/s20082210

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Language：English   Publishing type：Research paper (scientific journal)  

In recent years, the use of microinjections has increased in life science and biotechnology fields; specific examples include artificial insemination and gene manipulation. Microinjections are mainly performed based on visual information; thus, the operator needs high-level skill because of the narrowness of the visual field. Additionally, microinjections are performed as the operator views a microscopic image on a display; the position of the display requires the operator to maintain an awkward posture throughout the procedure. In this study, we developed a microscopic image display apparatus for microinjections based on a view-expansive microscope. The prototype of the view-expansive microscope has problems related to the variations in brightness and focal blur that accompany changes in the optical path length and amount of reflected light. Therefore, we propose the use of a variable-focus device to expand the visual field and thus circumvent the above-mentioned problems. We evaluated the observable area of the system using this variable-focus device. We confirmed that the observable area is 261.4 and 13.9 times larger than that of a normal microscope and conventional view-expansive microscopic system, respectively. Finally, observations of mouse embryos were carried out by using the developed system. We confirmed that the microscopic images can be displayed on a head-mounted display in real time with the desired point and field sizes.

DOI： 10.3390/s20071967

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Robotic teleoperation with force feedback has been studied extensively since it was first developed in the 1940 s. Time delay is a common problem of bilateral teleoperation systems. Although many efforts on optimizing the control architectures have been made, there is always a trade-off between transparency and stability for bilateral systems, and the perfect transparency and stability can only be achieved simultaneously in ideal situations. In this letter, we propose a novel approach to compensate for the degraded transparency while using the conventional passivity-based approach to maintain system stability under time-delay. The proposed approach is based on visual feedback and enhances the transparency by displaying different kinds of onomatopoeia according to contact force detected on the slave side. The basic performance is evaluated by conducting a stiffness classification task under constant round trip time delays (0 ms, 500 ms and 1000 ms). The preliminary results indicate that the subjects have higher accuracy for classifying the stiffness of a remote object by using onomatopoeia enhanced force feedback compared with the conventional passivity-based position-force feedback.

DOI： 10.1109/LRA.2020.2972896

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DOI： 10.3390/jfb11010018

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Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/TMECH.2019.2957494

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Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.robot.2019.103326

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Authorship：Last author   Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1186/s40648-019-0135-0

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Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1186/s40648-019-0145-y

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：THE INSTITUTE OF SYSTEMS, CONTROL AND INFORMATION ENGINEERS  

DOI： 10.11509/isciesci.63.10_424

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© 2019 IEEE. In this letter, we introduce our approach to walking assistance for elderly adults through predictive optimization of gait assistive force. We focus on providing supportive interaction force to the user during walking with a robotic assistive device with an admittance controlled mobile base. Appropriate physical human-robot interaction (pHRI) could be beneficial in reducing the risk associated with immobility such as disuse syndrome by encouraging physical activities with proper assistance. We propose an optimization algorithm based on a model predictive control approach in order to provide desirable assistive forces according to the estimated user's state during walking. Using a simplified human gait model with a linear inverted pendulum, we formulate the optimization of the assistive forces as a linear quadratic programming problem that can be suitable for real-time pHRI. Numerical simulations and experimental results demonstrate the feasibility of our gait support strategy in achieving appropriate compliant interactions during walking, fall prevention, and suitable positioning for user companion.

DOI： 10.1109/LRA.2019.2928770

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Nonlinear Dynamics  

This paper focuses on a transition motion between bipedal walking and running, whose characteristics have been revealed through numerous biological experiments. Although hysteresis in walk-to-run and run-to-walk transitions, the amount of which is proportional to the magnitude of acceleration/deceleration, is observed, it has not been elucidated yet. This is due to difficulty to conduct any biological experiments without the hysteresis in locomotion. From the viewpoint of nonlinear dynamics, the hysteresis is caused by dependency of the state history. Delays in perception and action for the walk–run transition can be assumed as the cause of the hysteresis. This paper therefore investigates i) whether the delays really cause the hysteresis in the walk–run transition, and ii) how they contribute to locomotion performance. To this end, in numerical simulations, we employ a controller for bipedal gait, named unified bipedal gait (UBG), which has capabilities of walking, running, and transitions between them like bipeds do. UBG is first optimized in pursue of biologically plausible controller with the same characteristics about the transition motion for reliable investigation. This optimized UBG reveals that the delays in perception and action actually cause the hysteresis with linearity of its amount and the magnitude of acceleration/deceleration. In addition, the delays play the key role of a bridge between latent representations of walking and running, thereby improving the success rate of the transition by nearly 40% from the case without the delays.

DOI： 10.1007/s11071-019-05097-0

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Language：English   Publishing type：Research paper (scientific journal)  

© 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group and The Robotics Society of Japan. Robot rehabilitation is now recognized as an important method for the efficient recovery. In European Project FP7 BioMot, we have discussed the potential of the robot rehabilitation and proposed the suitable process for it. In this paper, we describe the proposed rehabilitation process and create the theoretical basis for the robot rehabilitation through designing the control system and the patient model. To design the patient model, we describe the source of paralysis and motion controller separately and define the recovery function from the paralysis. In the theoretical analysis of the control system, we show that the robot motions are first adapted to the patient abnormal motions and gradually drive the patient motions to the better ones by the motion support. The singular perturbation analysis proves that the stabilities of the two different process, adaptation to the patient motions and the motion support to the better ones, as a slow motion subsystem and a fast motion subsystem, respectively. The simulation results show that the proposed control system can drive the patients to the better state depending on the patient conditions such as recovery speed and recovery potential. The proposed system can be tuned to fit to the variety of the real patient conditions when we apply it to the real applications.

DOI： 10.1080/01691864.2019.1633402

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DOI： 10.1186/s406480190136z

Language：English   Publishing type：Research paper (scientific journal)  

© 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group and The Robotics Society of Japan. Extra robotic limbs in a robotic system that are designed to augment and expand human abilities have received attention in the field of wearable robotics. We aim to develop a robotic system that is controlled by body parts that are not used on a daily basis in order to augment and expand human abilities. This paper presents operational learning experiments for manipulating a robotic thumb using the posterior auricular muscle, a body part that is not used in everyday life. In these experiments, reaching motions were executed using sensory feedback in the robotic thumb through a device that continuously displays its position. The experimental results indicate the proposed operational learning experiments improve the ability to contract the posterior auricular muscles. In addition, the results indicate the operability of a robotic thumb could be improved by acquiring internal models through repetitive operational learning.

DOI： 10.1080/01691864.2019.1566090

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Authorship：Last author   Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1186/s40648-018-0100-3

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Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1186/s40648-018-0115-9

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Language：English   Publishing type：Research paper (scientific journal)  

© 2018 IEEE. This paper proposes an electrical stimulation system to provide a lower limb motion state for paraplegic patients wearing an exoskeleton. The system consists of a glove-type exoskeleton controller and an electric stimulation device. In addition, a mechanical leg, which simulates a paraplegic&#039;s lower limb wearing an exoskeleton, was developed to conduct the preliminary experiment. The operator using his finger voluntarily controls the movement of the mechanical leg through the glove-type controller. Meanwhile, he receives electrical stimulation feedback that represents the output torque of the mechanical leg. In this manner, the system makes a connection between finger&#039;s motion and electrical stimulation. The operator could predict the feedback when he controls the mechanical leg. Finally, weight discrimination experiments were implemented to evaluate the accuracy of the electrical stimulation system. The subjects control the mechanical leg and receive electrical stimulation with different weight loading on the mechanical leg. The experimental results indicate that: 1) The dynamic of the mechanical leg is integrated into the body scheme of the subjects after training. 2) The subjects are capable of distinguishing a 17 percent change of weight loading at the minimum under the feedback of electric stimulation.

DOI： 10.1109/IISR.2018.8535936

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Authorship：Last author   Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1115/1.4040354

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.3389/fnbot2018.00043

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Language：English   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.robot.2018.02.005

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEEE Robotics and Automation Magazine  

The IEEE Robotics and Automation Society (RAS) Technical Committee (TC) on Wearable Robotics was approved during the IEEE RAS Technical Activities Board meeting that was held 15 May 2016 in Stockholm, Sweden, along with the IEEE International Conference on Robotics and Automation (ICRA) 2016. The TC maintained a high level of activities, including the organization of a series of scientific events such as conferences, summer schools, and special sessions/workshops in major RAS and non-RAS conferences, as well as leading special issues in prestigious Institute for Scientific Information journals. The TC provided a platform to promote international initiatives, innovative and industrial solutions for the assistance of frail people, which would provide an excellent opportunity to share information and technology transfer between experts from different fields such as medical, social, caregiving, and industry.

DOI： 10.1109/MRA.2017.2787222

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Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1088/1748-605X/aaa4c4

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Authorship：Last author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Robotics Society of Japan  

<p>Recent progress in the Lab on Chip (LOC) technology has made it possible to analyze microscale objects in microfluidic devices under a microscopic environment. Vision-based microscopic analysis systems have a limitation in terms of their analysis range owing to the limited view area of the optical microscope used in photomicroscopy. Thus, expansion of the view area during microscopic observation is required. In this paper, we propose a view expansion system for photomicroscopy based on the viewpoint movement using a Galvano mirror. We develop a prototype of the proposed microscopic view expansion system that consists of a microscope, a Galvano mirror, and a vision system. Experiments are conducted to compare the view area of the proposed microscopic system and a normal microscopic system; the photographable range of the developed system is experimentally derived and evaluated. Finally, our system is demonstrated through panoramic image developing experiments for an expanded view area. </p>

DOI： 10.7210/jrsj.36.294

CiNii Research

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Frontiers in Neurorobotics  

An important function missing from current robotic systems is a human-like method for creating behavior from symbolized information. This function could be used to assess the extent to which robotic behavior is human-like because it distinguishes human motion from that of human-made machines created using currently available techniques. The purpose of this research is to clarify the mechanisms that generate automatic motor commands to achieve symbolized behavior. We design a controller with a learning method called tacit learning, which considers system-environment interactions, and a transfer method called mechanical resonance mode, which transfers the control signals into a mechanical resonance mode space (MRM-space). We conduct simulations and experiments that involve standing balance control against disturbances with a two-degree-of-freedom inverted pendulum and bipedal walking control with humanoid robots. In the simulations and experiments on standing balance control, the pendulum can become upright after a disturbance by adjusting a few signals in MRM-space with tacit learning. In the simulations and experiments on bipedal walking control, the robots realize a wide variety of walking by manually adjusting a few signals in MRM-space. The results show that transferring the signals to an appropriate control space is the key process for reducing the complexity of the signals from the environment and achieving diverse behavior.

DOI： 10.3389/fnbot.2018.00043

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Authorship：Last author   Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.ifacol.2018.11.543

Scopus

Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEEE-RAS International Conference on Humanoid Robots  

When a paraplegic patient walks with the aid of an exoskeleton, the patient can only follow the preset walking trajectory and cannot receive any lower limb sensory feedback. This paper firstly proposes an index finger interface that allows a paraplegic patient to control the walking trajectory through an index finger voluntarily. The proposed interface consists of two rotatable links and one ring, and the interface is installed in the front of a crutch handle. The user controls the foot position of the foot position via a ring while keeping the balance with the crutch. On this basis, this paper also proposes an electrical stimulation feedback pattern that conveys the foot position to the user to assist the walking control. The electrical stimulation device contains 20 stimulation points that correspond to the spatial position. The electrical stimulus presents the foot position by switching the stimulation frequency and the stimulation position. For safety reasons, we conducted a preliminary study of the interface and feedback model with a healthy subject and a walking robot. We validated the effectiveness of the index finger interface and the electrical stimulation pattern through three experiments:1)pseudo-Trajectory recognition under electrical stimulation feedback condition, 2) robot walking control under visual feedback condition, and 3) robot walking control under electrical stimulation feedback condition.

DOI： 10.1109/HUMANOIDS.2017.8246963

Scopus

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE International Conference on Intelligent Robots and Systems  

In this paper, we introduce a walking load control strategy with a cane-type robot for gait training. The population of elderly people is increasing in most of the developed countries, and there is a growing demand for caregivers. Assistive robots are expected as a solution to provide aid in order to reduce the burden of caregivers in gait training of elderly people. Our research group has been developing a series of cane-type walking assistive robots named Intelligent Cane on admittance control to provide safe and efficient gait training. We propose an adaptive design method of the admittance control model in order to control user's walking load for the purpose of rapid improvement of user's physical strength. In the proposed method, the cane robot automatically adjusts control parameters of an admittance control model based on a correlation between a set of admittance parameters and a user's walking energy consumption. We conducted experiments to evaluate the proposed adaptive control strategy through a convergence error between estimated walking load and target one while walking training. We confirm the advantage of using the cane robot in rehabilitation.

DOI： 10.1109/IROS.2017.8202202

Scopus

Authorship：Last author   Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.robot.2017.09.009

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Scopus

Authorship：Last author   Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/TBCAS.2017.2764118

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DOI： https://doi.org/10.1155/2017/1610372

Authorship：Last author   Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：2017 IEEE International Conference on Cyborg and Bionic Systems, CBS 2017  

Our research purpose is to improve the utility of wearable robotic devices such as an extra robotic limb or finger with the help of acquiring a new body representation. One of the challenging problems of the conventional robotic prosthesis or wearable systems is their difficulty in the coordination of multiple degrees of freedom. Newly acquired body representation of the wearable robotic extremities could be helpful for a user to control the device as if they were a part of user's body. This paper introduces a posterior auricular muscle to obtain a new body representation of an extra robotic thumb. The posterior auricular muscle is one of vestigial muscle which does not have any body representation, while a daily used muscle has already had a certain body representation related with its functionality. In this paper, we conduct an experiment to test our hypothesis that a new body representation can be more easily acquired with the use of vestigial muscles than that of the muscles used in daily basis for the control of the extra robotic thumb. We compare the operability of the extra robotic thumb in reaching experiments by the use of muscles with different functionalities.

DOI： 10.1109/CBS.2017.8266101

Scopus

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/MHS.2017.8305257

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Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/LRA.2017.2655625

Web of Science

Scopus

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.actbio.2016.12.020

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Scopus

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.3390/app7020170

Web of Science

Scopus

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/978-3-319-32180-6_23

Web of Science

Authorship：Lead author   Publishing type：Research paper (scientific journal)   Publisher：The Society of Instrument and Control Engineers  

DOI： 10.9746/sicetr.53.1

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)  

This paper proposes an wearable MRI-compatible hand exoskeleton robot that supports a subject moving his fingers voluntarily or involuntarily in high electromagnetic field. The hand robot consists of four exoskeletal fingers excluding a thumb, which is fabricated with nonmagnetic materials through 3D printing. In order to work in an MRI environment, pneumatic actuators are applied to drive the joints of the wearable robot. Potentiometers are installed in the MP and PIP joints of four fingers to measure the angles of finger’s motions. Basic performances of the robot are evaluated by flexion rang of fingers, time delay and fingertip force. In the future, the compatibility of robot in MRI environment will be confirmed through measurement experiments of a subject’s brain activity.

DOI： 10.1007/978-3-319-65289-4_23

Scopus

Language：English   Publishing type：Research paper (scientific journal)   Publisher：16th International Conference on Nanotechnology - IEEE NANO 2016  

Nanotool feeding system (NTFS) is presented for efficient nanomanipulation. We constructed a unique bio-nanomanipulation system inside an Environmental-SEM (E-SEM) using various nanotools, for example stiffness measurement nanotool, dual electrical nanoprobe, nanopicker, nanofork, nanocutter, nanoputter, and nanoinjector. For continues usage of different multiple tools, it needs to exchange the nanotools continuously. In this paper, the Rotary-table Nanotool Feeding System (R-NTFS) is proposed to realize continuous exchange of different multiple tools individually. An efficient continuous nanomanipulation was achieved by a short exchange time which was about 13 seconds. Finally, the multiple nanoinjection was demonstrated using the proposed R-NTFS.

DOI： 10.1109/NANO.2016.7751541

Scopus

Language：English   Publishing type：Research paper (scientific journal)  

© 2016, Springer Science+Business Media Dordrecht. In this paper, we propose an adaptive speed controller (ASC) for a limit-cycle-based gait classified as a three-dimensional (3-D) bipedal gait. The limit-cycle-based gait of bipedal robots is excellent for energy efficiency. However, the forward and sideward moving speeds of these robots are difficult to control since they are autonomous systems and their behavior depends upon the initial states of every step. Therefore, in this study, we design a swing leg motion to appropriately adjust the initial states of every step. First, the forward speed is controlled by injecting the momentum of the swing leg, which shifts an energy equilibrium point from the original point to the reference point where the reference forward speed is achieved. Second, the sideward speed is controlled by asymmetric touchdown positions on the right and the left legs, which separate the limit cycle into two different limit cycles for each leg, and this separation leads to the sideward motion. The proposed ASC can be easily applied to an arbitrary limit-cycle-based gait because it is independent of the dynamics of the gait model. The performance of the proposed ASC was validated in terms of the residual error, step response, and disturbance rejection capabilities in numerical simulations for two examples of walking. The proposed ASC also achieved a highly energy-efficient gait, which was consistent with the analytical results. Further, the proposed ASC could adapt a robot to various environments that contained up and down slopes or an obstacle.

DOI： 10.1007/s11071-016-2645-0

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.actbio.2016.03.045.

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/TMECH.2015.2477996

Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/SII.2015.7405154

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Other Link： https://dblp.uni-trier.de/db/conf/sii/sii2015.html#AyamuraNTHPHF15

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 50 Adaptive speed controller using swing leg motion for 3-D limit-cycle-based bipedal gait

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers Inc.  

© 2016 IEEE. Constructing 3D cell module with certain shape and high cell density is a very important issue for artificial tissue engineering. In this letter, we present a novel method of fabricating compact microtissue with gear-like shape by electrodepositing of Ca 2+ induced cross-linked alginate hydrogel. The fabrication procedure is demonstrated and the fabricated gear-like tissues are characterized. Briefly, an array of gear-shaped microelectrodes are first fabricated by coating a patterned photoresist layer onto fluorine-doped tin oxide (FTO) glass slide based on photolithography technique. Then, Ca-alginate gel structures embedded with RLC-18 (rat liver) cells are electrodeposited onto the microelectrodes. These 2D cell-laden gel structures are then manually detached from the microelectrodes and treated with special reagent to be transformed into 3D alginate-Poly-L-lysine (PLL) microcapsules while maintaining the gear shape. Finally, the RLC-18 cells within the microcapsules are further promoted into compact microtissues by cultivation. The size of the fabricated gear-like tissue is about 975±25 μm in outer diameter and 320±10 μm in inner diameter based on the design of microelectrodes. 3-D images of the fabricated microtissues are obtained by a confocal microscope. The experimental results indicate the proposed method can successfully fabricate movable microtissues with predefined gear shape while maintaining the viability (∼94%). We believe the fabricated movable gear-like microtissues can be further assembled and applied to tissue engineering.

DOI： 10.1109/LRA.2016.2514500

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.3390

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Fuji Technology Press Ltd.  

<p>This study proposes a vision-based mowing boundary detection algorithm for an autonomous lawn mower. An autonomous lawn mower requires high moving accuracy for efficient mowing. This problem is solved by using a vision system to detect the boundary of two regions, i.e., before and after the lawn mowing process. The mowing boundary cannot be detected directly because it is ambiguous. Therefore, we utilize a texture classification method with a bank of filters for classifying the input image of the lawn field into two regions as mentioned above. The classification is performed by threshold processing based on a chi-squared statistic. Then, the boundary line is detected from the classified regions by using Random sample consensus (RANSAC). Finally, we apply the proposed method to 12 images of the lawn field and verified that the proposed method can detect a mowing boundary line with centimeter accuracy in a dense lawn field.</p>

DOI： 10.20965/jaciii.2016.p0049

Open Access

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CiNii Research

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/TNB.2015.2507064

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1299/transjsme.14-00634

Language：English   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/HUMANOIDS.2014.7041360

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Other Link： https://dblp.uni-trier.de/db/conf/humanoids/humanoids2014.html#KobayashiSAHF14

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Mechanical Engineers  

This paper proposes a presentation interface of hip joint angle for paraplegic patient using a small electrode array. Current powered exoskeletons help the patient's walk on the basis of biopotential signal. However, the exoskeletons have two problems. First, patient's intentions related to a walk are not synchronized with the assistive leg motions completely. Second, paraplegic patients with the exoskeleton cannot perceive legs' information such as joint angles and floor contact because the patients have lost afferent signal flows. We proposed a finger-mounted walk controller for the first problem before. However, the controller is not based on human nerve system. In addition, we proposed feedback device for conveying hip joints angle by electric stimulation for the second problem before. However, the patients have to cover their all fingers with electrodes for using the device. To control legs on the basis of human nerve system and to miniaturize presentation parts, we propose a presentation interface of hip joint angle for paraplegic patient using a small electrode array.

DOI： 10.1299/jsmermd.2015._1a1-q04_1

CiNii Research

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Mechanical Engineers  

This paper proposes the vision-based mowing boundary detection algorithm for an automatic lawn mower. The proposed algorithm utilizes the idea of a bank of filters, which consists of 36 Gabor filters, to capture the change of the features before and after mowing the lawn. The x^2 statistic is calculated as the feature value from the filter responses. The input image of lawn environment with two fields before and after mowing the lawn is classified into two classes by utilizing the x^2 statistic. The boundary between two classes is determined by RANSAC.

DOI： 10.1299/jsmermd.2015._2p1-c02_1

CiNii Research

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Mechanical Engineers  

The purpose of this paper is to achieve Japanese syllabary identification for a tissue-related articulation person who has an abnormality in the shape of mouth and the tongue. The device assists his/her communication with other persons without utterance since they cannot utter well. The device that a support vector machine is incorporated in reads the intended Japanese syllabary based on myoeletric potential using an array electrode attached on the anterior surface of neck. As a first step, an experiment is conducted in order to identify Japanese syllabary (46 kinds) and rest state. As a result, the average of identification accuracy is 96.6% and even worst accuracy of the specific sound is more than 80%.

DOI： 10.1299/jsmermd.2015._2a2-j06_1

CiNii Research

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Mechanical Engineers  

Passive dynamic autonomous control (PDAC) for bipedal walking has excellent efficiency. PDAC, however, can control walking direction only in the previous research, and not be used for 3-D walking currently. We then propose a 3-D walking method of PDAC by using a walking speed controller based on a swing-leg motion. The reference walking speed to reach the goal is achieved by adjusting the touchdown position and speed of the swing leg. As a result, the 3-D walking is achieved with the high energy efficiency, although the footstep is hardly controllable.

DOI： 10.1299/jsmermd.2015._1p2-b09_1

CiNii Research

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Mechanical Engineers  

Recently, a lot of researches for bipedal locomotion have been conducted. The high-speed running, which means that a Froude number is more than 1 so the robot can conduct only it, has not been achieved until now. In this research, we develop a humanoid robot that achieves the high-speed running, named rapid running robot (R3). The development and control of this robot need an accurate model to analyze the robot's locomotion. We then model R^3 after a real robot, which has already achieved the running, in a dynamic simulator V-REP.

DOI： 10.1299/jsmermd.2015._1p2-b05_1

CiNii Research

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Mechanical Engineers  

This paper presents the aqueous observation of three-dimensional information using scanning electron microscope- computed tomography (SEM-CT) inside an environmental-SEM (E-SEM). It is required to control the sample temperature for an aqueous condition inside the E-SEM. In this paper, a cooling system was installed into the SEM-CT system. The aqueous observation was confirmed by the E-SEM and SEM-CT observations.

DOI： 10.1299/jsmermd.2015._1p1-p03_1

CiNii Research

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Mechanical Engineers  

We evaluated a survival rate of micro-injection into Caenorhabditis elegans, (C. elegans) after 24 hours with a fluorescent micro-gel bead. The fluorescent micro-gel beads were fabricated by a salting-out method. One of the micro-gel bead was picked up at the micropipette injection tool by suction forces. The microbead was injected into C. elegans by a microinjector using a piezo actuator based on micromanipulation. After microinjection of the fluorescent microbead, the microbead was confirmed in the C. elegans using a fluorescent and a confocal microscopes. From experimental results, the viabilities were achieved in 71 % (12/17) and 62% (8/13) at 10 μm and 20 μm different injection depths.

DOI： 10.1299/jsmermd.2015._1p1-o10_1

CiNii Research

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Mechanical Engineers  

We constructed three dimensional (3D) microchannel networks inside gelatin-based hydrogel towards 3D in vitro cell structures. The 3D assembly of cells in vitro is one of the important techniques to reveal cell growth, differentiation and hystogenesis for applications in tissue engineering, drug screening, and cell characterization. To achieve functional 3D cell structures, vascular networks are important to supply oxygen and nutrients to cells, and remove waste product from cells. An alginate hydrogel fibers were employed to construct the microchannel networks like blood vessels. The patterned hydrogel fiber can be melted using standard saline citrate (SSC) buffer and the melted area can be used as vascular networks. The flow inside the melted alginate hydrogel fibers were visualized using fluorescent microbeads. The results validate that the proposed method can be used to make arbitrary patterns of vascular networks inside cell structures and contribute to achieve in vitro 3D cell structures.

DOI： 10.1299/jsmermd.2015._1p1-o03_1

CiNii Research

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Mechanical Engineers  

In this paper, we conducted the fabrication of cell embedded structures using biodegradable photocrosslinkable material gelatin methacrylate (GelMA). The mouse fibroblast NIH3T3 cells were mixed in uncured GelMA solution. The cell embedded microcstructures were fabricated by exposing ultra violet (UV) light under a microscope. The cell culture was conducted to check their growth inside the microstructures. The cell viability was checked using live/dead cell staining. The observation of cell structures under a confocal microscope was conducted to check the three dimensional shape of the structure. The experimental results validate that the cells can grow inside the GelMA structures and the fabricated structures can be used to construct in vitro 3D cell structures for tissue engineering applications.

DOI： 10.1299/jsmermd.2015._1p1-n03_1

CiNii Research

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Mechanical Engineers  

We propose a new method to construct microchannels inside cell structures. Recently, three-dimensional cell structures have been actively developed such as cell sheets stacking or inkjet bio-printing method. However, those methods have some disadvantages such as stacking rate or non-biodegradable materials. In this paper, local melting of cell embedded hydrogel is employed to make microchannels inside cell structures. The fabricated microchannels can be used as vascular-like networks to supply nutrition and oxygen to cells. Temperature distribution inside the hydrogel was simulated using 1D unsteady heat conduction equation. A microchannel was experimentally fabricated using an electrode on a glass substrate. The results indicate that the proposed method can be used to making vascular-like networks inside cell structures to construct in vitro 3D cell systems.

DOI： 10.1299/jsmermd.2015._1p1-n02_1

CiNii Research

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Mechanical Engineers  

This paper presents a fabrication of graphene cubic structure by a nanomanipulation in a FESEM (Field Emission Scanning Electron Microscope). We developed two nanomanipulators with three degrees of freedoms to handle two end-effectors. A cube net was designed and fabricated using a multi graphene by a FIB (Focused Ion Beam) etching. For bending the one side of the cubic net graphene, a tungsten probe was used after reforming by FIB etching to adjust the cube net design. The multi graphene was bent to form a cubic 3D structure in study. Additionally, the bending forces of multi graphene were measured using a silicon cantilever based on the nanomanipulation.

DOI： 10.1299/jsmermd.2015._1a1-x06_1

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)  

Web of Science

Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Mechanical Engineers  

Automation of agricultural machines has been required for labor saving to manage farms. The purpose of this research is to develop a vision-based guidance method for an autonomous vehicle in vineyard environments. In this paper, we propose a method of vanishing point detection focusing on similarity structure of vineyard environments. An advantage of the proposed method is not to be affected by illumination conditions. We applied the proposed method to 17 images and evaluated the usefulness by positional errors of a vanishing point.

DOI： 10.1299/jsmeicam.2015.6.278

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)  

Web of Science

Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Mechanical Engineers  

This paper introduces an exoskeleton for reduction in a metabolic cost during running. The exoskeleton aims to reduce load of runner's vertical oscillation of center of mass. The exoskeleton consists of a leaf spring, a slider and a brake unit for holding and releasing the slider of each leg. The exoskeleton holds the slider during a stance phase and releases the slider during a swing phase. For assisting the oscillation, the leaf spring stores energy during an initial stance phase and restore the energy during a terminal stance phase. A heart rate of a subject shows assistance effect of the exoskeleton through running.

DOI： 10.1299/jsmeicam.2015.6.21

CiNii Research

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Springer Verlag  

Joint stiffness of the exoskeleton robot is one of the most important factors to support bipedal walking. In this paper, we discuss the robot joint stiffness tuning algorithm using the bio-mimetic learning method called tacit learning. We experimentally showed that the pro- posed controller can tune the joint stiffness of the exoskeleton robot by tuning the integral gain in the controller. The walking experiment wear- ing the exoskeleton robot suggest that the stiffness tuning is applicable to control the walking speed.

DOI： 10.1007/978-3-319-24917-9_15

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEEE International Conference on Intelligent Robots and Systems  

This paper proposes a pneumatic tubular body fixture for a wearable assistive device in order to hold a user body in simple wearing actions and with comfort. The pneumatic body fixture, called active cuff, is composed of multiple sets of a pneumatic actuator module which are actively transformed by compressed air. This transformed module wraps and holds a part of a user's body so that a wearable assistive device can be mounted on the user's body with less effort in a short time. The elastic material of the pneumatic actuator module also contributes a tactile and pressure sensation of a contact with the environment as if we could feel those sensations through our clothes. The pneumatic actuator is modeled by a beam structure and then deformation of the pneumatic actuator is simulated by finite element method for an active cuff design. The maximum holding force of the developed active cuff is about 6 kilograms, which is enough to hold an upper limb. The active cuff changes the holding points to keep blood flow of the holding area iteratively and alternatively using three couples of pneumatic actuator modules of the active cuff. Through some experiments, we confirmed that the active cuff enhanced the convenience and comfort of the wearable robot from the viewpoints of easiness to wear and the contact pressure distribution.

DOI： 10.1109/IROS.2014.6942850

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Cybernics: Fusion of human, machine and information systems  

DOI： 10.1007/978-4-431-54159-2

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Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/IROS.2014.6942650

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

J-GLOBAL

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

This paper proposes a finger-mounted user interface device and a cooperative control algorithm for complete paraplegic patient to walk with a powered exoskeleton. Current walk support systems actually help the patient walking. However, they have limitations to adjust its walk as a patient intends, such as stride, foot height, and so on. In our research, a pair of finger interface devices is developed for a patient to convey his/her intention to the walk support system. As the first step, a walking robot was developed to simulate the patient body and the walk support system. A 10-meter walking experiment was conducted to evaluate feasibility of the interface device and a control algorithm to start leg-swing. We confirmed that the timing of the leg-swing was adjusted as the user intended through the interface and that the 10-meter walk was finished in four minutes.

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Event date： 2024.12

Language：English   Presentation type：Oral presentation (general)  

Country：United States  

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Event date： 2024.11

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Event date： 2024.11

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Country：Japan  

Event date： 2024.9

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Venue：宇都宮  

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Venue：宇都宮  

Event date： 2024.8

Language：English   Presentation type：Oral presentation (general)  

Venue：Tianjin   Country：China  

DOI： 10.1109/ICMA61710.2024.10632998

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Venue：Boston   Country：United States  

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Event date： 2024.5 - 2024.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇都宮  

Event date： 2024.5 - 2024.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇都宮  

Event date： 2024.5 - 2024.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇都宮  

Event date： 2024.5 - 2024.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇都宮  

Event date： 2024.5 - 2024.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇都宮  

Event date： 2024.5 - 2024.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇都宮  

Event date： 2024.5 - 2024.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇都宮  

Event date： 2024.5

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：愛知県名古屋市   Country：Japan  

Event date： 2024.5

Language：English   Presentation type：Poster presentation  

Venue：Nagoya University   Country：Japan  

Event date： 2024.5

Language：English   Presentation type：Poster presentation  

Venue：Nagoya University   Country：Japan  

Event date： 2024.5

Language：English   Presentation type：Poster presentation  

Venue：Nagoya University   Country：Japan  

Event date： 2024.5

Language：English   Presentation type：Poster presentation  

Venue：Yokohama   Country：Japan  

Event date： 2024.5

Language：English   Presentation type：Poster presentation  

Venue：Yokohama   Country：Japan  

Event date： 2024.5

Language：English   Presentation type：Poster presentation  

Venue：Yokohama   Country：Japan  

Event date： 2024.1

Language：English   Presentation type：Oral presentation (general)  

Venue：Halong   Country：Viet Nam  

Event date： 2024.1

Language：English   Presentation type：Oral presentation (general)  

Venue：Halong   Country：Viet Nam  

Event date： 2023.11

Language：English   Presentation type：Oral presentation (general)  

Event date： 2023.11

Language：English   Presentation type：Oral presentation (general)  

Event date： 2023.11

Language：English   Presentation type：Poster presentation  

Event date： 2023.11

Language：English   Presentation type：Oral presentation (general)  

Event date： 2023.11

Language：English   Presentation type：Oral presentation (general)  

Event date： 2023.11

Language：English   Presentation type：Oral presentation (general)  

Event date： 2023.11

Language：English   Presentation type：Oral presentation (general)  

Event date： 2023.11

Language：English   Presentation type：Oral presentation (general)  

Event date： 2023.11

Language：English   Presentation type：Oral presentation (general)  

Event date： 2023.11

Language：English   Presentation type：Oral presentation (general)  

Event date： 2023.10

Language：English   Presentation type：Oral presentation (general)  

Country：United Arab Emirates  

Event date： 2023.10

Language：English   Presentation type：Oral presentation (general)  

Country：United Arab Emirates  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Event date： 2023.9

Language：English   Presentation type：Oral presentation (general)  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Event date： 2023.8

Language：English   Presentation type：Oral presentation (general)  

Country：Korea, Republic of  

Event date： 2023.8

Language：English   Presentation type：Oral presentation (general)  

Country：China  

Event date： 2023.7

Language：English   Presentation type：Oral presentation (general)  

Country：China  

Event date： 2023.6 - 2023.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋  

Event date： 2023.6 - 2023.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋  

Event date： 2023.6 - 2023.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋  

Event date： 2023.6 - 2023.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋  

Event date： 2023.6 - 2023.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋  

Event date： 2023.6 - 2023.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋  

Event date： 2023.6 - 2023.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋  

Event date： 2023.4

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：東京都千代田区   Country：Japan  

Event date： 2023.4

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2023.4

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2023.3

Language：English   Presentation type：Oral presentation (general)  

Country：China  

Event date： 2023.3

Language：English   Presentation type：Oral presentation (general)  

Country：China  

Event date： 2023.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：和歌山県白浜   Country：Japan  

Event date： 2022.12

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2022.12

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2022.11

Language：English   Presentation type：Oral presentation (general)  

Event date： 2022.11

Language：English   Presentation type：Oral presentation (general)  

Event date： 2022.11

Language：English   Presentation type：Oral presentation (general)  

Event date： 2022.11

Language：English   Presentation type：Oral presentation (general)  

Event date： 2022.11

Language：English   Presentation type：Oral presentation (general)  

Event date： 2022.11

Language：English   Presentation type：Oral presentation (general)  

Event date： 2022.10

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2022.10

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

DOI： 10.1109/IROS47612.2022.9982247

Event date： 2022.9

Language：English   Presentation type：Oral presentation (general)  

Event date： 2022.9

Language：Japanese   Presentation type：Oral presentation (general)