Elsevier BV Acta Medica Okayama 0196-6553 53 1 2025 Effectiveness of sensing gloves–applied virtual reality education system on hand hygiene practice: A randomized controlled trial 65 69 EN Mahiro Izumi Quality Assurance Center, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Hideharu Hagiya Department of Infectious Diseases, Okayama University Hospital Yuki Otsuka Department of General Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yoshiaki Soejima Department of General Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Shinnosuke Fukushima Department of Infectious Diseases, Okayama University Hospital Mitsunobu Shibata Quality Assurance Center, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Satoshi Hirota Quality Assurance Center, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Toshihiro Koyama Department of Health Data Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Fumio Otsuka Department of General Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Akio Gofuku Quality Assurance Center, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Background: We developed a virtual reality (VR) education system and evaluated its clinical utility for promoting hand hygiene practices. Methods: This prospective, 2-week, randomized controlled study conducted at Okayama University Hospital, Japan, from November 2023 to January 2024, involved 22 participants (18 medical students and 4 residents). A fully immersive 360° VR system (VIVE Pro Eye) using a head-mounted display and sensing gloves was used to develop 3 health care tasks in a virtual patient room―Environmental Cleaning, Gauze Exchange, and Urine Collection. After monitoring all participants' baseline usage data of portable hand-rubbing alcohol in the first week, we randomly assigned them into 1:1 groups (VR training and video lecture groups). The primary outcome was differences in hand-rubbed alcohol use before and after intervention. Results: Before the intervention, alcohol use did not significantly differ between both groups. After the intervention, a significant increase in alcohol use was observed in the VR training group (median: 8.2 g vs 16.2 g; P = .019) but not in the video lecture group. Conclusions: Our immersive 360° VR education system enhanced hand hygiene practices. Infection prevention and control practitioners and digital technology experts must collaborate to advance the development of superior educational devices and content. No potential conflict of interest relevant to this article was reported.

岡山大学大学院ヘルスシステム統合科学研究科 Acta Medica Okayama 2436-3227 4 2024 ⼈類社会の持続的発展に貢献する統合科学 1 17 EN Akio GOFUKU Okayama University 10.18926/interdisciplinary/66892 With the increase of the complexity of human society because of the globalization and the advancement of each scientific field, innovations by effective collaborations of experts in various fields become necessary to solve problems in human society and to increase the findings of each field. From the backgrounds, the interdisciplinary science b ecomes popular in recent y ears. This article p resents the approach of interdisciplinary science and its importance to the sustainable development of human society. As an example of studies by interdisciplinary science, this article introduces a virtual reality based mirror visual feedback therapy system that the author has been developed in collaboration with medical doctors, professors in engineering field and students of the author’s laboratory in Okayama University. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 2076-0825 12 11 2023 Development of Hexagonal Pyramid-Shaped Flexible Actuator with Anisotropic Stiffness for Upper-Limb Rehabilitation Device 424 EN So Shimooka Faculty of Environmental, Life, Natural Science and Technology, Okayama University Hiroki Himuro Faculty of Interdisciplinary Science and Engineering in Health Systems, Okayama University Akio Gofuku Faculty of Interdisciplinary Science and Engineering in Health Systems, Okayama University Rehabilitation devices for passive exercise have been actively researched and developed in accordance with Japan's aging society. A previous study proposed and tested an extension-type flexible pneumatic actuator (EFPA) with reinforced stiffness that could achieve passive exercise in patients. In addition, a rehabilitation device for shoulder joints with an embedded controller and small valves was proposed and tested. Joints such as the shoulder and scapula were subjected to passive exercise utilizing the tested device. However, it is difficult for patients with contractions to perform the same exercise because the reinforced EFPA can buckle. Here, to realize an EFPA with a higher stiffness, a flexible actuator in the shape of a hexagonal pyramid is proposed and tested. The hexagonal pyramid shape of a flexible actuator has a high stiffness in the direction of motion and flexibility in other directions; hereafter, this characteristic is called anisotropic stiffness. The characteristics of the hexagonal pyramid shape of the EFPA are described and compared with those of a previously reinforced EFPA. An analytical model was proposed to predict and design the shape of the hexagonal pyramid EFPA. The validity of the model is also described. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0924-4247 361 2023 A soft rotary actuator with a flexible shaft using flexible pneumatic actuators 114603 EN So Shimooka Faculty of Natural Science and Technology, Okayama University Miku Kawanaka Faculty of Interdisciplinary Science and Engineering in Health Systems, Okayama University Akio Gofuku Faculty of Interdisciplinary Science and Engineering in Health Systems, Okayama University This paper proposes a soft rotary actuator that can rotate even when its shaft is bent. The tested rotary actuator consists of three Extension-type Flexible Pneumatic Actuators (EFPA), flexible plates for restraining the EFPAs geometrically, and a polyurethane tube as a shaft. The EFPA consists of a silicone rubber tube covered with a sleeve that can expand significantly in the axial direction when the tube is pressurized. By restraining the EFPA to a helical shape using plates, the proposed rotary actuator can rotate when the three EFPAs are extended in the rotational direction upon the application of pressure. It is confirmed that the tested actuator could rotate even if the shaft is bent, because the shaft and EFPAs consist of flexible materials. The maximum rotation angle and torque are approximately 400° and 0.5 Nm, respectively, for an input pressure of 500 kPa. An analytical model of the tested actuator is proposed to predict the relationship between the rotation angle and the input pressure. A comparison between the calculated and experimental rotation angles reveals that the experimental results can be accurately predicted using the proposed analytical model, which considers the effects of EFPA friction and restraining. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 2075-4418 13 8 2023 Deep Active Learning for Automatic Mitotic Cell Detection on HEp-2 Specimen Medical Images 1416 EN Asaad Anaam Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Mugahed A. Al-antari Department of Artificial Intelligence, College of Software & Convergence Technology, Daeyang AI Center, Sejong University Jamil Hussain Department of Data Science, College of Software & Convergence Technology, Daeyang AI Center, Sejong University Nagwan Abdel Samee Department of Information Technology, College of Computer and Information Sciences, Princess Nourah bint Abdulrahman University Maali Alabdulhafith Department of Information Technology, College of Computer and Information Sciences, Princess Nourah bint Abdulrahman University Akio Gofuku Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Identifying Human Epithelial Type 2 (HEp-2) mitotic cells is a crucial procedure in anti-nuclear antibodies (ANAs) testing, which is the standard protocol for detecting connective tissue diseases (CTD). Due to the low throughput and labor-subjectivity of the ANAs' manual screening test, there is a need to develop a reliable HEp-2 computer-aided diagnosis (CAD) system. The automatic detection of mitotic cells from the microscopic HEp-2 specimen images is an essential step to support the diagnosis process and enhance the throughput of this test. This work proposes a deep active learning (DAL) approach to overcoming the cell labeling challenge. Moreover, deep learning detectors are tailored to automatically identify the mitotic cells directly in the entire microscopic HEp-2 specimen images, avoiding the segmentation step. The proposed framework is validated using the I3A Task-2 dataset over 5-fold cross-validation trials. Using the YOLO predictor, promising mitotic cell prediction results are achieved with an average of 90.011% recall, 88.307% precision, and 81.531% mAP. Whereas, average scores of 86.986% recall, 85.282% precision, and 78.506% mAP are obtained using the Faster R-CNN predictor. Employing the DAL method over four labeling rounds effectively enhances the accuracy of the data annotation, and hence, improves the prediction performance. The proposed framework could be practically applicable to support medical personnel in making rapid and accurate decisions about the mitotic cells' existence. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1424-8220 22 14 2022 A Heartbeat Classifier for Continuous Prediction Using a Wearable Device 5080 EN Eko Sakti Pramukantoro Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Akio Gofuku Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Heartbeat monitoring may play an essential role in the early detection of cardiovascular disease. When using a traditional monitoring system, an abnormal heartbeat may not appear during a recording in a healthcare facility due to the limited time. Thus, continuous and long-term monitoring is needed. Moreover, the conventional equipment may not be portable and cannot be used at arbitrary times and locations. A wearable sensor device such as Polar H10 offers the same capability as an alternative. It has gold-standard heartbeat recording and communication ability but still lacks analytical processing of the recorded data. An automatic heartbeat classification system can play as an analyzer and is still an open problem in the development stage. This paper proposes a heartbeat classifier based on RR interval data for real-time and continuous heartbeat monitoring using the Polar H10 wearable device. Several machine learning and deep learning methods were used to train the classifier. In the training process, we also compare intra-patient and inter-patient paradigms on the original and oversampling datasets to achieve higher classification accuracy and the fastest computation speed. As a result, with a constrain in RR interval data as the feature, the random forest-based classifier implemented in the system achieved up to 99.67% for accuracy, precision, recall, and F1-score. We are also conducting experiments involving healthy people to evaluate the classifier in a real-time monitoring system. No potential conflict of interest relevant to this article was reported.

IEEE-Inst Electrical Electronics Engineers Inc Acta Medica Okayama 2169-3536 9 2021 Studying the Applicability of Generative Adversarial Networks on HEp-2 Cell Image Augmentation 98048 98059 EN Asaad Anaam Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Hani M. Bu-Omer Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Akio Gofuku Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University The Anti-Nuclear Antibodies (ANAs) testing is the primary serological diagnosis screening test for autoimmune diseases. ANAs testing is conducted mainly by the Indirect Immunofluorescence (IIF) on Human Epithelial cell-substrate (HEp-2) protocol. However, due to its high variability, human-subjectivity, and low throughput, there is an insistent need to develop an efficient Computer-Aided Diagnosis system (CADs) to automate this protocol. Many recently proposed Convolutional Neural Networks (CNNs) demonstrated promising results in HEp-2 cell image classification, which is the main task of the HE-p2 IIF protocol. However, the lack of large labeled datasets is still the main challenge in this field. This work provides a detailed study of the applicability of using generative adversarial networks (GANs) algorithms as an augmentation method. Different types of GANs were employed to synthesize HEp-2 cell images to address the data scarcity problem. For systematic comparison, empirical quantitative metrics were implemented to evaluate different GAN models' performance of learning the real data representations. The results of this work showed that though the high visual similarity with the real images, GANs' capacity to generate diverse data is still limited. This deficiency in the generated data diversity is found to be of a crucial impact when used as a standalone method for augmentation. However, combining limited-size GANs-generated data with classic augmentation improves the classification accuracy across different variants of CNNs. Our results demonstrated a competitive performance for the overall classification accuracy and the mean class accuracy of the HEp-2 cell image classification task. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 2076-3425 11 6 2021 Parieto-Occipital Alpha and Low-Beta EEG Power Reflect Sense of Agency 743 EN Hani M. Bu-Omer Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Akio Gofuku Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Kenji Sato Department of Anesthesiology and Intensive Care Medicine, Kawasaki Medical School Makoto Miyakoshi Swartz Center for Computational Neuroscience, Institute for Neural Computation, University of California San Diego The sense of agency (SoA) is part of psychophysiological modules related to the self. Disturbed SoA is found in several clinical conditions, hence understanding the neural correlates of the SoA is useful for the diagnosis and determining the proper treatment strategies. Although there are several neuroimaging studies on SoA, it is desirable to translate the knowledge to more accessible and inexpensive EEG-based biomarkers for the sake of applicability. However, SoA has not been widely investigated using EEG. To address this issue, we designed an EEG experiment on healthy adults (n = 15) to determine the sensitivity of EEG on the SoA paradigm using hand movement with parametrically delayed visual feedback. We calculated the power spectral density over the traditional EEG frequency bands for ten delay conditions relative to no delay condition. Independent component analysis and equivalent current dipole modeling were applied to address artifact rejection, volume conduction, and source localization to determine the effect of interest. The results revealed that the alpha and low-beta EEG power increased in the parieto-occipital regions in proportion to the reduced SoA reported by the subjects. We conclude that the parieto-occipital alpha and low-beta EEG power reflect the sense of agency. No potential conflict of interest relevant to this article was reported.

岡山大学大学院ヘルスシステム統合科学研究科 Acta Medica Okayama 2436-3227 1 2021 看護場⾯における確認不⾜を引き起こす要因の認識に関する検討 29 45 EN Wanxin Zuo Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Yoshimi Hyodo Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Tomoko Tanaka Graduate School of Humanities and Social Sciences, Okayama University Akio Gofuku Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University 10.18926/interdisciplinary/61888 In the work process of nurses with high risk, it is very urgent to take countermeasures against the “lack of confirmation” of the main factors. Therefore, the purpose of this study is to clarify the details of the factors leading to the lack of confirmation, grasp the number of near misses, and to explore what kind of factors the individual characteristics of the nurse who acts as a stopper. We recruited 500 nurses on the Web and asked about the frequency of near misses due to lack of confirmation, the awareness of the causes of lack of confirmation, self-evaluation of stoppers, and the reasons why near misses did not lead to accidents. As a result, three factors were extracted regarding the recognition of the factors of lack of confirmation: "lack of consciousness", "inability to concentrate", and "lack of knowledge / experience". Three factors were extracted for self-evaluation of stopper characteristics: "awareness," "verification," and "cautiousness". In order to reduce the lack of confirmation, it is necessary to secure and allocate appropriate personnel and create an environment where treatment can be concentrated. Nurses should also raise knowledge and the awareness of the importance of confirmation. In addition, it is necessary to improve the clinical judgment of new nurses in order to prevent near misses. And it is thought that new nurses will become more confident by accumulating experience and affirming their abilities from their superiors, seniors and colleagues. No potential conflict of interest relevant to this article was reported.

岡山大学大学院ヘルスシステム統合科学研究科 Acta Medica Okayama 2436-3227 1 2021 『統合科学』の創刊にあたって 1 1 EN Akio Gofuku Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University No potential conflict of interest relevant to this article was reported.

AIP Publishing Acta Medica Okayama 0094-243X 2180 2019 Consideration to Display Operator Support Information to Human Operators under High Mental Pressure 020028 EN Akio Gofuku Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Operator support systems are extensively studied and developed to support human operators for their activities in especially an abnormal condition of a nuclear power plant. By the advancement of computer technology and artificial intelligence, an operator support system can provide detailed support information based on detailed models and utilizing detailed simulation of plant dynamics and/or complicated inference algorithms. However, human operators may not understand the detailed support information under high mental pressure in an abnormal plant condition. In such a case, it is important how to provide essential and understandable support information. This paper deals with a technique to simplify functional models in order to display operator support information that is generated based on detailed functional models. This paper defines eight cognitive states of human operators from the viewpoint of cognitive abilities of human. In addition, three ways to simplify functional models are identified. No potential conflict of interest relevant to this article was reported.

TAYLOR & FRANCIS Acta Medica Okayama 0169-1864 2019 Development of a separable search-and-rescue robot composed of a mobile robot and a snake robot EN Tetsushi Kamegawa Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Taichi Akiyama Graduate School of Natural Science and Technology, Okayama University Satoshi Sakai Graduate School of Natural Science and Technology, Okayama University Kento Fujii Graduate School of Natural Science and Technology, Okayama University Kazushi Une Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Eitou Ou Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Yuto Matsumura Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Toru Kishutani Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Eiji Nose Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Yusuke Yoshizaki Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Akio Gofuku Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, In this study, we propose a new robot system consisting of a mobile robot and a snake robot. The system works not only as a mobile manipulator but also as a multi-agent system by using the snake robot's ability to separate from the mobile robot. Initially, the snake robot is mounted on the mobile robot in the carrying mode. When an operator uses the snake robot as a manipulator, the robot changes to the manipulator mode. The operator can detach the snake robot from the mobile robot and command the snake robot to conduct lateral rolling motions. In this paper, we present the details of our robot and its performance in the World Robot Summit. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 70 3 2016 Structure of a New Palatal Plate and the Artificial Tongue for Articulation Disorder in a Patient with Subtotal Glossectomy 205 211 EN Ken-ichi Kozaki Department of Dental Pharmacology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Shigehisa Kawakami Department of Occlusal and Oral Functional Rehabilitation, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takayuki Konishi Division of Physical Medicine and Rehabilitation, Okayama University Hospital Keiji Ohta Dental Laboratory Division, Okayama University Hospital Jitsuro Yano Department of Occlusal and Oral Functional Rehabilitation, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tomoo Onoda Department of Otolaryngology-Head and Neck Surgery Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Hiroshi Matsumoto Department of Plastic and Reconstructive Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Nobuyoshi Mizukawa Department of Oral and Maxillofacial Reconstructive Surgery, Okayama University Hospital Yoshihiro Kimata Department of Plastic and Reconstructive Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kazunori Nishizaki Department of Otolaryngology-Head and Neck Surgery Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Seiji Iida Department of Oral and Maxillofacial Reconstructive Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Akio Gofuku Graduate School of Natural Science and Technology, Okayama University Masanobu Abe Department of Computer Science, Okayama University Shogo Minagi Department of Occlusal and Oral Functional Rehabilitation, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama Dream Speech Project Case Report 10.18926/AMO/54420 A palatal augmentation prosthesis (PAP) is used to facilitate improvement in the speech and swallowing functions of patients with tongue resection or tongue movement disorders. However, a PAPʼs effect is limited in cases where articulation disorder is severe due to wide glossectomy and/or segmental mandibulectomy. In this paper, we describe speech outcomes of a patient with an articulation disorder following glossectomy and segmental mandibulectomy. We used a palatal plate (PP) based on a PAP, along with an artificial tongue (KAT). Speech improvement was evaluated by a standardized speech intelligibility test consisting of 100 syllables. The speech intelligibility score was significantly higher when the patient wore both the PP and KAT than when he wore neither (p＝0.013). The conversational intelligibility score was significantly improved with the PP and KAT than without PP and KAT (p＝0.024). These results suggest that speech function can be improved in patients with hard tissue defects with segmental mandibulectomy using both a PP and a KAT. The nature of the design of the PP and that of the KAT will allow these prostheses to address a wide range of tissue defects. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2004 A study of reinforcement learning with knowledge sharing 175 180 EN Kazuyuki Ito Yoshiaki Imoto Hideaki Taguchi Akio Gofuku In this paper, we consider multi-agent system in which every agents have own tasks that differs each other. We propose a method that decreases learning time of reinforcement learning by using the model of environment. In the proposed algorithm, the model is created by sharing the experiences of agents each other. To demonstrate the effectiveness of the proposed method, simulations of a puddle world and experiments of a maze world have been carried out. As a result effective behaviors have been obtained quickly. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 1 2003 Path evaluation for a mobile robot based on a risk of collision 485 490 EN Masahiro Irie Keiji Nagatani Akio Gofuku An odometry system that mobile robot uses for positioning has cumulative error because of wheels' slippage and uneven ground. It causes a risk of collision of obstacles. Therefore, we propose a path evaluation method for a mobile robot based on a risk of collision. To evaluate a robot's path, we define an evaluation value as an integral of a risk of collision along the path. To evaluate the risk of collision at each point, we use an estimated positioning error generated in the odometry system. Using the evaluation method, the robot can plan a path based on a risk of collision, not the shortest path. We also consider sensing points planning for position adjustment of the mobile robot, based on the same approach. Some examples of path evaluation results support a validity of the proposed method. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2006 A mechanical intelligence in assisting the navigation by a force feedback steering wheel for a snake rescue robot 113 118 EN Zhixiao Yang Kazuyuki Ito Kazuyuki Hirotsune Kazuhiko Saijo Akio Gofuku Fumitoshi Matsuno This paper applies our developed novice users oriented force feedback steering wheel interface and mouse interface to navigating a tank type rescue robot. By analyzing merits and limitation of operating each interface, we propose a combined navigation strategy by the two interfaces. The steering wheel interface consists of a force feedback steering control and a six monitors’ wall. Through this interface, users can navigate the tank robot like driving cars, while watching incoming videos. It provides a daily life operation method for novice users to navigate the tank rescue robot. The steering wheel interface is efficient in exploring open areas. For complex disaster fields, this interface requires users have skillful operation experiences, which take them more attention. The mouse-screen interface consists of a mouse and a camera’s view displayed in a computer screen. Through this interface, users can navigate the tank robot just by mouse clicking. Path planning and low-level controlling are realized by system automatically. The mouse-screen interface can realize exact navigation, especially needed in complex structures, without taking much attention. It gives users more time to care incoming information. The two interfaces can shift into each other at any time. The combined navigation strategy adopts merits of the two interfaces and compensates limitation of each of them. It provides an efficient operation method for novice users to navigate rescue robots. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2004 A mechanical intelligence in assisting the navigation by a force feedback steering wheel for a snake rescue robot 113 118 EN Zhixiao Yang Kazuyuki Ito Kazuyuki Hirotsune Kazuhiko Saijo Akio Gofuku Fumitoshi Matsuno We developed a snake rescue robot basing on the proposed mechanical intelligence. The mechanical intelligence is designed to avoid obstacles and to realize desired motions when the robot is navigated by a remote force feedback steering wheel interface. We use free joints to connect modules of the snake robot. Modules can freely turn according to their neighbors. An obstacle-avoiding wheel is mounted on the head of the snake robot. When the head encounters an obstacle, the wheel touches it first to transfer the sliding friction between the wheel and the obstacle into rolling friction, so that the head avoid the obstacle easily. A metal wire is used to link gears mounted on both sides of each module. When any part of the snake robot's body encounters an obstacle, the wire length of each side varies automatically to change the robot's body shape, so that the snake robot avoids the obstacle. The wire length of each side can also be adjusted by a motor. By adjusting the wire length of each side, the snake robot can move in the desired direction. The mechanical intelligence based snake rescue robot has light body, low cost and low computation cost. Experiment results show that the designed mechanical intelligence is effective in realizing desired robot motions together with the force feedback steering wheel interface. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 3 2003 A study of reinforcement learning with knowledge sharing for distributed autonomous system 1120 1125 EN Kazuyuki Ito Yoshiaki Imoto Akio Gofuku Mitsuo Takeshita Reinforcement learning is one of effective controller for autonomous robots. Because it does not need priori knowledge and behaviors to complete given tasks are obtained automatically be repeating trial and error. However a large number of trials are required to realize complex tasks. So the task that can be obtained using the real robot is restricted to simple ones. Considering these points, various methods that prove the learning cost of reinforcement learning have been proposed. In the method that uses priori knowledge, the methods lose the autonomy that is most important feature of reinforcement learning in applying it to the robots. In the Dyna-Q, that is one of simple and effective reinforcement learning architecture integrating online planning, a model of environment is learned from real experience and by utilizing the model to learn, the learning time is decreased. In this architecture, the autonomy is held, however the model depends on the task, so acquired knowledge of environment cannot be reused to other tasks. In the real world, human beings can learn various behaviors to complete complex tasks without priori knowledge of the tasks. We can try to realize the task in our image without moving our body. After the training in the image, by trying to the real environment, we save time to learn. It means that we have model of environment and we utilize the model to learn. We consider that the key ability that makes the learning process faster is construction of environment model and utilization of it. In this paper, we have proposed a method to obtain an environment model that is independent of the task. And by utilizing the model we have decreased learning time. We consider distributed autonomous agents, and we show that the environment model is constructed quickly by sharing the experience of each agent, even when each agent has own independent task. To demonstrate the effectiveness of the proposed method, we have applied the method to the Q-learning and simulations of a puddle world are carried out. As a result effective behaviors have been obtained quickly. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 3 2003 Hybrid autonomous control for heterogeneous multi-agent system 2500 2505 EN Kazuyuki Ito Akio Gofuku Reinforcement learning is an adaptive and flexible control method for autonomous system. In our previous works, we had proposed a reinforcement learning algorithm for redundant systems: "Q-learning with dynamic structuring of exploration space based on GA (QDSEGA)", and applied it to multi-agent systems. However previous works of the QDSEGA have been restricted to homogeneous agents. In this paper, we extend our previous works of multi-agent systems, and propose a hybrid autonomous control method for heterogeneous multi-agent systems. To demonstrate the effectiveness of the proposed method, simulations of transportation task by 10 heterogeneous mobile robots have been carried out. As a result effective behaviors have been obtained. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2004 A combined navigation strategy by a steering 239 244 EN Zhixiao Yang Kazuyuki Ito Kazuhiko Saijo Kazuyuki Hirotsune Akio Gofuku Fumitoshi Matsuno This paper applies our developed novice users oriented force feedback steering wheel interface and mouse interface to navigating a tank type rescue robot. By analyzing merits and limitation of operating each interface, we propose a combined navigation strategy by the two interfaces. The steering wheel interface consists of a force feedback steering control and a six monitors’ wall. Through this interface, users can navigate the tank robot like driving cars, while watching incoming videos. It provides a daily life operation method for novice users to navigate the tank rescue robot. The steering wheel interface is efficient in exploring open areas. For complex disaster fields, this interface requires users have skillful operation experiences, which take them more attention. The mouse-screen interface consists of a mouse and a camera’s view displayed in a computer screen. Through this interface, users can navigate the tank robot just by mouse clicking. Path planning and low-level controlling are realized by system automatically. The mouse-screen interface can realize exact navigation, especially needed in complex structures, without taking much attention. It gives users more time to care incoming information. The two interfaces can shift into each other at any time. The combined navigation strategy adopts merits of the two interfaces and compensates limitation of each of them. It provides an efficient operation method for novice users to navigate rescue robots. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2004 A combined navigation strategy by a steering wheel and a mouse for a tank rescue robot 239 244 EN Zhixiao Yang Kazuyuki Ito Kazuhiko Saijo Kazuyuki Hirotsune Akio Gofuku Fumitoshi Matsuno This paper applies our developed novice users oriented force feedback steering wheel interface and mouse interface to navigating a tank type rescue robot. By analyzing merits and limitation of operating each interface, we propose a combined navigation strategy by the two interfaces. The steering wheel interface consists of a force feedback steering control and a six monitors’ wall. Through this interface, users can navigate the tank robot like driving cars, while watching incoming videos. It provides a daily life operation method for novice users to navigate the tank rescue robot. The steering wheel interface is efficient in exploring open areas. For complex disaster fields, this interface requires users have skillful operation experiences, which take them more attention. The mouse-screen interface consists of a mouse and a camera’s view displayed in a computer screen. Through this interface, users can navigate the tank robot just by mouse clicking. Path planning and low-level controlling are realized by system automatically. The mouse-screen interface can realize exact navigation, especially needed in complex structures, without taking much attention. It gives users more time to care incoming information. The two interfaces can shift into each other at any time. The combined navigation strategy adopts merits of the two interfaces and compensates limitation of each of them. It provides an efficient operation method for novice users to navigate rescue robots. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 4 2003 Emergence of adaptive behaviors by redundant robots : Robustness to changes environment and failures 2572 2579 EN Kazuyuki Ito Akio Gofuku Acquiring adaptive behaviors of robots automatically is one of the most interesting topics of the evolutionary systems. In previous works, we have developed an adaptive autonomous control method for redundant robots. The QDSEGA is one of the methods that we have proposed for them. The QDSEGA is realized by combining Q-learning and GA, and it can acquire suitable behaviors by adapting a movement of a robot for a task. In this paper, we focus on the adaptability of the QDSEGA and discuss the robustness of the autonomous redundant robot that is controlled by the QDSEGA. To demonstrate the effectiveness of the QDSEGA, simulations of obstacle avoidance by a 10-link manipulator in the changeable environment and locomotion by a 12-legged robot with failures have been carried out, and as a result, adaptive behaviors for each environment and each broken body have emerged. No potential conflict of interest relevant to this article was reported.

Institute of Electrical and Electronics Engineers Acta Medica Okayama 2 1996 Development of a tactile sensing flexible actuator 723 728 EN Yutaka Tanaka Akio Gofuku Yuji Fujino The disadvantages of flexible artificial fingers have been improved. The finger is provided with the tactile sense by two types of sensors to detect when the finger tip touches an object and to estimate both the finger force and object size. The rigidity is enhanced by equipping the finger with a reinforcing material similar to that of human bone. A prototype robot hand with four fingers has been manufactured for experiments and mounted on an industrial articulated robot. The effectiveness of the improved robot hand finger was confirmed throughout experimental tests of grasping action No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 3 2000 Fundamental study of fluid transfer using electro-rheological effect 1827 1832 EN Yutaka Tanaka Akio Gofuku Considering that there is no pump feeding an Electro-Rheological-Fluid, a new type of pump has been manufactured and fluid dynamic characteristics have been elucidated. This pump can feed the ERF by utilizing effectively the change in physical properties of the fluid by the application of voltage. The principle and configuration of this pump and the methods of theoretical analysis are described, and the influence of the voltage on the feeding characteristics was examined The dispersoidal ERF has been treated hitherto as a type of Newtonian fluid. However. experiments showed that not only the induced shear stress but also the viscosity is affected by the electric field strength and that the ERF must be treated as a pseudo-plastic flow. The method of analysis described here can be applied to design the pump differing in dimensions because the analysis gave qualitative evaluations about the flow rate and pressure difference No potential conflict of interest relevant to this article was reported.

Institute of Electrical and Electronics Engineers Acta Medica Okayama 1999 Development of a video-rate range finder using dynamic threshold method for characteristic point detection 932 937 EN Yutaka Tanaka Akio Gofuku Nobuo Takeda Isaku Nagai This study develops a video-rate stereo range finding circuit to obtain the depth of objects in a scene by processing video signals (R, G, B, and brightness signals) from binocular CCD cameras. The electronic circuit implements a dynamic threshold method to decrease the affect of signal noise in characteristic point detection, where a video signal from each CCD camera is compared with multiple thresholds, shifting dynamically by feeding back the previous comparison result. Several object depth measurement experiments for simple indoor scenes show that the dynamic threshold method gives high acquisition and correct rates of depth data compared with those by a fixed threshold method for the video signals and a relative method for R, G, and B signals utilized in the authors' previous range finders. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 1997 Analysis of electric-fluid analogy of pressure transmission through an electro-rheological-fluid in annuli 67 72 EN Yutaka Tanaka Akio Gofuku Keiji Nakamura The article concerns the development of flexible robotic fingers using electro-rheological fluid (ERF) for pressure control. It describes a technique to predict the transient response of a pressure control device using ERF by an electric-flow analogy. The inertia is calculated from the theoretical equation. The resistance and additional voltage source by the ER effect are derived theoretically by assuming the flow in the electrode annuli of the pressure control device as a flow of the Bingham fluid. The capacitance is determined to compare the time-responses of pressures by the prediction based on a model with the results of a simple experiment. The predictions of transient flow, using the determined parameters of the model are in qualitatively good agreement with the experimental results No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2002 Motion planning for mobile manipulator with keeping manipulability 1663 1668 EN Keiji Nagatani Tomonobu Hirayama Akio Gofuku Yutaka Tanaka Our research goal is to realize a motion planning for an intelligent mobile manipulator. To plan a mobile manipulator's motion, it is popular that the base robot motion is regarded as manipulator's extra joints, and the whole system is considered as a redundant manipulator. In this case, the locomotion controller is a part of the manipulator controller. However, it is difficult to implement both controllers as one controller, in our implementation experience, because of difference of actuators' character. In this research, we focus on a path planning algorithm for a mobile base with keeping manipulability at the tip of the mounted manipulator. In this case, the locomotion controller is independent from the manipulator controller, and a cooperative motion is realized by a communication between both controllers. In this paper, we propose a motion planning algorithm for a mobile manipulator, and report several experimental results. No potential conflict of interest relevant to this article was reported.