666 research outputs found

    Portable Dextrous Force Feedback Master for robot telemanipulation (PDMFF)

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    A major drawback of open loop masters is a lack of force feedback, limiting their ability to perform complex tasks such as assembly and repair. Researchers present a simple dextrous force feedback master for computer assisted telemanipulation. The device is compact, portable and can be held in the operator hand, without the need for a special joystick or console. The system is capable of both position feed forward and force feedback, using electronic position sensors and a pneumatic micro-actuator. The level of forces exercised by the pneumatic actuator is such that near rigidity may be attained. Experimental results showing good system linearity and small time lag are given

    Maintained hand function and forearm bone health 14 months after an in-home virtual-reality videogame hand telerehabilitation intervention in an adolescent with hemiplegic cerebral palsy

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    Virtual reality videogames can be used to motivate rehabilitation, and telerehabilitation can be used to improve access to rehabilitation. These uses of technology to improve health outcomes are a burgeoning area of rehabilitation research. So far, there is a lack of reports of long-term outcomes of these types of interventions. The authors report a 15-year-old boy with hemiplegic cerebral palsy and epilepsy because of presumed perinatal stroke who improved his plegic hand function and increased his plegic forearm bone health during a 14-month virtual reality videogame hand telerehabilitation intervention. A total of 14 months after the intervention ended, repeat evaluation demonstrated maintenance of both increased hand function and forearm bone health. The implications of this work for the future of rehabilitation in children with neurological disabilities are discussed in this article

    implementation of tactile sensors on a 3 fingers robotiq adaptive gripper and visualization in vr using arduino controller

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    Abstract Tactile sensors are essential components for the implementation of complex manipulation tasks using robot grippers, allowing to directly control the grasping force according to the object properties. Virtual Reality represents an effective tool capable of visualizing complex systems in full details and with a high level of interactivity. After the implementation of cost-effective tactile arrays on a 3-finger Robotiq ® gripper using an ARDUINO controller, it is presented an innovative VR interface capable of visualizing the pressure values at the fingertips in a 3D environment, providing an effective tool aimed at supporting the programming and the visualization of the gripper VR

    Hierarchical Compliance Control of a Soft Ankle Rehabilitation Robot Actuated by Pneumatic Muscles

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    Traditional compliance control of a rehabilitation robot is implemented in task space by using impedance or admittance control algorithms. The soft robot actuated by pneumatic muscle actuators (PMAs) is becoming prominent for patients as it enables the compliance being adjusted in each active link, which, however, has not been reported in the literature. This paper proposes a new compliance control method of a soft ankle rehabilitation robot that is driven by four PMAs configured in parallel to enable three degrees of freedom movement of the ankle joint. A new hierarchical compliance control structure, including a low-level compliance adjustment controller in joint space and a high-level admittance controller in task space, is designed. An adaptive compliance control paradigm is further developed by taking into account patient’s active contribution and movement ability during a previous period of time, in order to provide robot assistance only when it is necessarily required. Experiments on healthy and impaired human subjects were conducted to verify the adaptive hierarchical compliance control scheme. The results show that the robot hierarchical compliance can be online adjusted according to the participant’s assessment. The robot reduces its assistance output when participants contribute more and vice versa, thus providing a potentially feasible solution to the patient-in-loop cooperative training strateg

    Essays in strategic information transmission

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    This thesis contributes to the literature on strategic information transmission through providing new insights into strategic behavior under several communication frameworks. The thesis is comprised of five chapters. Chapter 1 provides an overview of the main topics and research methodologies presented in the next three chapters. Chapter 2 reports experiments in sender-receiver games with partially verifiable messages. We explore the role of verification control on strategic behavior and final outcomes. We find that behavior is closer to theoretical predictions when senders have verification control. However, the setting in which receivers have control over the verification action promotes higher average payoffs despite behavior being noisier. Chapter 3 investigates the effect of cheap talk on the interpretation of partially informative verifiable communication (evidence). Using experimental data from sender-receiver games similar to those in chapter 2 we find that cheap talk distorts receivers’ appraisal of evidence. Specifically, it makes receivers depart from theoretical predictions more than they do in a treatment where cheap talk is not present. Chapter 4 explores the effect of cheap talk in a sender-receiver game with sender state independent preferences and a state space with non-uniform distribution. This type of state space leads to the interests of the players to be either more likely aligned, or more likely conflicting. Using a simple theoretical analysis we show that if receivers dislike taking an action that is profitable for a deceiving sender (“sucker aversion”), communication can harm when interests are more likely aligned. However, when interests are more likely conflicting, communication helps due to senders’ “lying aversion”. We run experiments to test these predictions and find no effect of cheap talk when interests are more likely aligned. When interests are more likely conflicting, communication has a positive effect on payoffs but not due to the hypothesized mechanism. Chapter 5 provides a summary of the previous chapters’ results as well as a discussion which points out the limitations. Finally it delineates welcomed directions for future research

    A game prototype for understanding the safety issues of a lifeboat launch

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    © 2018 The Author(s) Novel, advanced game techniques provide us with new possibilities to mimic a complicated training process, with the added benefit of enhanced safety. In this paper, we design and implement a 3D game with the support of virtual reality equipment which imitates the process of a lifeboat launch, involving both tractor manoeuvres and boat operations. It is a complex but vital process which can save lives at sea but also has many potential hazards. The primary objective of the game is to allow novices to better understand the sequence of the operations and manage the potential risks which may occur during the launch process. Additionally, the game has been promoted to the general public for educational purposes and to raise awareness of the safety issues involved. The key modules of the game are designed based on physical simulations to give the players enhanced plausible cognition and enjoyable interaction. We conducted two case studies for the two purposes of the games: one for training with volunteers without launching experience and the other for public awareness of the potential hazards with young children. The game is proven to be very promising for future professional training, and it serves the educational purpose of awareness of the safety issues for general public while being entertaining

    Feasibility study into self-administered training at home using an arm and hand device with motivational gaming environment in chronic stroke

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    © 2015 Nijenhuis et al. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.BACKGROUND: Assistive and robotic training devices are increasingly used for rehabilitation of the hemiparetic arm after stroke, although applications for the wrist and hand are trailing behind. Furthermore, applying a training device in domestic settings may enable an increased training dose of functional arm and hand training. The objective of this study was to assess the feasibility and potential clinical changes associated with a technology-supported arm and hand training system at home for patients with chronic stroke. METHODS: A dynamic wrist and hand orthosis was combined with a remotely monitored user interface with motivational gaming environment for self-administered training at home. Twenty-four chronic stroke patients with impaired arm/hand function were recruited to use the training system at home for six weeks. Evaluation of feasibility involved training duration, usability and motivation. Clinical outcomes on arm/hand function, activity and participation were assessed before and after six weeks of training and at two-month follow-up. RESULTS: Mean System Usability Scale score was 69 % (SD 17 %), mean Intrinsic Motivation Inventory score was 5.2 (SD 0.9) points, and mean training duration per week was 105 (SD 66) minutes. Median Fugl-Meyer score improved from 37 (IQR 30) pre-training to 41 (IQR 32) post-training and was sustained at two-month follow-up (40 (IQR 32)). The Stroke Impact Scale improved from 56.3 (SD 13.2) pre-training to 60.0 (SD 13.9) post-training, with a trend at follow-up (59.8 (SD 15.2)). No significant improvements were found on the Action Research Arm Test and Motor Activity Log. CONCLUSIONS: Remotely monitored post-stroke training at home applying gaming exercises while physically supporting the wrist and hand showed to be feasible: participants were able and motivated to use the training system independently at home. Usability shows potential, although several usability issues need further attention. Upper extremity function and quality of life improved after training, although dexterity did not. These findings indicate that home-based arm and hand training with physical support from a dynamic orthosis is a feasible tool to enable self-administered practice at home. Such an approach enables practice without dependence on therapist availability, allowing an increase in training dose with respect to treatment in supervised settings. TRIAL REGISTRATION: This study has been registered at the Netherlands Trial Registry (NTR): NTR3669 .Peer reviewe
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