Pub Date : 2007-06-13DOI: 10.1109/ICORR.2007.4428533
Hyung‐Soon Park, Yi-Ning Wu, Y. Ren, Li-Qun Zhang
A portable tele-assessment system was designed for remote evaluation of the elbow joint with spasticity and contracture in patients with neurological disorders. A master device and a slave device were used to drive a manikin arm and the patient's arm, respectively. The elbow flexion angle and torque were measured at both the master and slave devices, fed back to their counterparts. The examiner moved the manikin arm at selected velocities and haptically felt the resistance from the patient's elbow to evaluate the spasticity in terms of the velocity dependence of the resistance torque and the catch angle. To minimize the effect of network latency in the tasks with fast speed, a quasi real-time tele-operation scheme was developed which provided the examiner with transparent and stable haptic feeling of the patient's elbow. The tele-assessment system provided truthful haptic feeling through the internet and allowed us to evaluate the spasticity in elbows of patients post stroke quantitatively.
{"title":"A Tele-Assessment System for Evaluating Elbow Spasticity in Patients with Neurological Impairments","authors":"Hyung‐Soon Park, Yi-Ning Wu, Y. Ren, Li-Qun Zhang","doi":"10.1109/ICORR.2007.4428533","DOIUrl":"https://doi.org/10.1109/ICORR.2007.4428533","url":null,"abstract":"A portable tele-assessment system was designed for remote evaluation of the elbow joint with spasticity and contracture in patients with neurological disorders. A master device and a slave device were used to drive a manikin arm and the patient's arm, respectively. The elbow flexion angle and torque were measured at both the master and slave devices, fed back to their counterparts. The examiner moved the manikin arm at selected velocities and haptically felt the resistance from the patient's elbow to evaluate the spasticity in terms of the velocity dependence of the resistance torque and the catch angle. To minimize the effect of network latency in the tasks with fast speed, a quasi real-time tele-operation scheme was developed which provided the examiner with transparent and stable haptic feeling of the patient's elbow. The tele-assessment system provided truthful haptic feeling through the internet and allowed us to evaluate the spasticity in elbows of patients post stroke quantitatively.","PeriodicalId":197465,"journal":{"name":"2007 IEEE 10th International Conference on Rehabilitation Robotics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114962825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-06-13DOI: 10.1109/ICORR.2007.4428525
K. Yoshida, M. Kurstjens, L. Citi, K. Koch, S. Micera
This paper presents our experience evaluating a multi-channel peripheral nerve interface, the thin-film longitudinal intra-fascicular electrode (tfLIFE). One application for the tfLIFE is their potential use as a means to detect independent channels of volitional commands from the amputee. The neural interface would be required to be sufficiently selective to detect the activity of single motor nerve fibres within the nerve stump. Experiments were conducted in the acute rabbit model evaluate the recording characteristics of the tfLIFE array. Multiunit activity was recorded in response to mechanical stimulation of peripheral mechanoreceptors. In some channels in all experiments, large single unit spikes were clearly visible. These data were then processed to determine whether an artificial discriminator could be trained to detect and track activity from the multi unit recordings. We also tested whether inclusion of multi channel information could be used to improve the performance of the discriminator. Our preliminary results indicate the inclusion of multiple channels significantly improves the performance.
{"title":"Recording experience with the thin-film Longitudinal Intra-Fascicular Electrode, a multichannel peripheral nerve interface","authors":"K. Yoshida, M. Kurstjens, L. Citi, K. Koch, S. Micera","doi":"10.1109/ICORR.2007.4428525","DOIUrl":"https://doi.org/10.1109/ICORR.2007.4428525","url":null,"abstract":"This paper presents our experience evaluating a multi-channel peripheral nerve interface, the thin-film longitudinal intra-fascicular electrode (tfLIFE). One application for the tfLIFE is their potential use as a means to detect independent channels of volitional commands from the amputee. The neural interface would be required to be sufficiently selective to detect the activity of single motor nerve fibres within the nerve stump. Experiments were conducted in the acute rabbit model evaluate the recording characteristics of the tfLIFE array. Multiunit activity was recorded in response to mechanical stimulation of peripheral mechanoreceptors. In some channels in all experiments, large single unit spikes were clearly visible. These data were then processed to determine whether an artificial discriminator could be trained to detect and track activity from the multi unit recordings. We also tested whether inclusion of multi channel information could be used to improve the performance of the discriminator. Our preliminary results indicate the inclusion of multiple channels significantly improves the performance.","PeriodicalId":197465,"journal":{"name":"2007 IEEE 10th International Conference on Rehabilitation Robotics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121816348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-06-13DOI: 10.1109/ICORR.2007.4428447
A. Duschau-Wicke, J. von Zitzewitz, R. Banz, R. Riener
Functional and task-oriented robotic rehabilitation training can be improved by the interaction of the patient with real-world objects. If these objects are not directly coupled to the robot, a synchronization of robot and object is required, comparable to a calibration between the end effector of an industrial robot and a work piece. Such synchronization prevents from safety hazards and unwanted tension forces at the man-machine interface between robot and patient or patient and object. In this paper, we propose a combination of an iterative learning synchronization (ILS) and an immediate error correction (IEC) technique to automate such synchronization processes. The feasibility of these methods is demonstrated by using them to automatically synchronize the gait rehabilitation robot Lokomat with a treadmilL.
{"title":"Iterative Learning Synchronization of Robotic Rehabilitation Tasks","authors":"A. Duschau-Wicke, J. von Zitzewitz, R. Banz, R. Riener","doi":"10.1109/ICORR.2007.4428447","DOIUrl":"https://doi.org/10.1109/ICORR.2007.4428447","url":null,"abstract":"Functional and task-oriented robotic rehabilitation training can be improved by the interaction of the patient with real-world objects. If these objects are not directly coupled to the robot, a synchronization of robot and object is required, comparable to a calibration between the end effector of an industrial robot and a work piece. Such synchronization prevents from safety hazards and unwanted tension forces at the man-machine interface between robot and patient or patient and object. In this paper, we propose a combination of an iterative learning synchronization (ILS) and an immediate error correction (IEC) technique to automate such synchronization processes. The feasibility of these methods is demonstrated by using them to automatically synchronize the gait rehabilitation robot Lokomat with a treadmilL.","PeriodicalId":197465,"journal":{"name":"2007 IEEE 10th International Conference on Rehabilitation Robotics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116669877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-06-13DOI: 10.1109/ICORR.2007.4428511
Sivakumar Balasubramanian, J. Ward, Thomas G. Sugar, Jiping He
The potential effectiveness and adoption of robotic assisted therapy for neural rehabilitation has attracted increased attention to the development of rehabilitation robots. Our research group had developed a lightweight exoskeletal rehabilitation robot actuated by pneumatic muscle actuators. To design a robust control system with intelligent adaptation to individual patient's condition is a challenge with pneumatic muscle actuators (PMA). The dynamics of a PMA is affected by dimension (length and diameter), pressure and load. Thus, it is crucial to choose the appropriate PMA with the desired dynamic response for each of the joints to be actuated. In this study, 2nd order phenomenological models have been developed to describe the dynamic behavior of nine pneumatic muscle actuators (3 different lengths and 3 different diameters). The important differences between these pneumatic muscle actuators are compared based on the model parameters. Some of the model parameters like relative muscle contraction, rise natural frequency are affected more by the PMA dimensions, while some of the other parameters are relatively unaffected by the dimensions of the PMA. In addition, analytical expressions were determined for the individual model parameters as functions of the input pressure and external load.
{"title":"Characterization of the Dynamic Properties of Pneumatic Muscle Actuators","authors":"Sivakumar Balasubramanian, J. Ward, Thomas G. Sugar, Jiping He","doi":"10.1109/ICORR.2007.4428511","DOIUrl":"https://doi.org/10.1109/ICORR.2007.4428511","url":null,"abstract":"The potential effectiveness and adoption of robotic assisted therapy for neural rehabilitation has attracted increased attention to the development of rehabilitation robots. Our research group had developed a lightweight exoskeletal rehabilitation robot actuated by pneumatic muscle actuators. To design a robust control system with intelligent adaptation to individual patient's condition is a challenge with pneumatic muscle actuators (PMA). The dynamics of a PMA is affected by dimension (length and diameter), pressure and load. Thus, it is crucial to choose the appropriate PMA with the desired dynamic response for each of the joints to be actuated. In this study, 2nd order phenomenological models have been developed to describe the dynamic behavior of nine pneumatic muscle actuators (3 different lengths and 3 different diameters). The important differences between these pneumatic muscle actuators are compared based on the model parameters. Some of the model parameters like relative muscle contraction, rise natural frequency are affected more by the PMA dimensions, while some of the other parameters are relatively unaffected by the dimensions of the PMA. In addition, analytical expressions were determined for the individual model parameters as functions of the input pressure and external load.","PeriodicalId":197465,"journal":{"name":"2007 IEEE 10th International Conference on Rehabilitation Robotics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117146511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-06-13DOI: 10.1109/ICORR.2007.4428488
Nitin Williams, Faustina Hwang
As the number and proportion of older people worldwide continues to grow, robotic devices can play a role in helping older people continue to live independent and active lives. Graphical user interfaces (GUIs) and interactions that involve pointing to items and selecting them are becoming more common in assistive robots. The authors are currently working on a project investigating techniques to improve point-select interactions for older people. In particular, the project studies how older people respond to expanding and moving targets. The research is ongoing, and this paper describes the methods that will be used in upcoming experiments.
{"title":"Investigating Novel Point-select Techniques for Older People","authors":"Nitin Williams, Faustina Hwang","doi":"10.1109/ICORR.2007.4428488","DOIUrl":"https://doi.org/10.1109/ICORR.2007.4428488","url":null,"abstract":"As the number and proportion of older people worldwide continues to grow, robotic devices can play a role in helping older people continue to live independent and active lives. Graphical user interfaces (GUIs) and interactions that involve pointing to items and selecting them are becoming more common in assistive robots. The authors are currently working on a project investigating techniques to improve point-select interactions for older people. In particular, the project studies how older people respond to expanding and moving targets. The research is ongoing, and this paper describes the methods that will be used in upcoming experiments.","PeriodicalId":197465,"journal":{"name":"2007 IEEE 10th International Conference on Rehabilitation Robotics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126068503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-06-13DOI: 10.1109/ICORR.2007.4428439
N. Pernalete, Ramakrishna Gottipati, J. Grantner, S. Edwards, D. Janiak, J. Haskin, R. Dubey
This paper is the continuation of a work presented at ICORR 05, in which the results of single-subjects studied suggested that the haptic robotic therapy proposed improved eye-hand coordination in children diagnosed with this problem, using a robotic mapping from a haptic user interface to a virtual environment. This paper presents the integration of the aforementioned system with an intelligent decision support system (IDSS) based on fuzzy-logic. Our goal is to develop an assessment and training procedure that will result in improving handwriting taking the advantage of the force feedback provided by the haptic device and the intelligence provided by the IDSS. We also incorporate the inertia and viscosity effects to decrease the tremor in the hand as well as to stimulate the muscles involved in the task of holding a pencil (known as facilitation technique in the Occupational Therapy field). The IDSS is based upon a fuzzy automaton. By using qualitative (fuzzified) data from the previous tests executed by the subject, the system will make a decision on the complexity of the next test to be performed. It is expected that this automated system will reduce the burden and the associated cost of having a trained professional present in all assessment/training sessions.
{"title":"Integration of an Intelligent Decision Support System and a Robotic Haptic Device for Eye-Hand Coordination Therapy","authors":"N. Pernalete, Ramakrishna Gottipati, J. Grantner, S. Edwards, D. Janiak, J. Haskin, R. Dubey","doi":"10.1109/ICORR.2007.4428439","DOIUrl":"https://doi.org/10.1109/ICORR.2007.4428439","url":null,"abstract":"This paper is the continuation of a work presented at ICORR 05, in which the results of single-subjects studied suggested that the haptic robotic therapy proposed improved eye-hand coordination in children diagnosed with this problem, using a robotic mapping from a haptic user interface to a virtual environment. This paper presents the integration of the aforementioned system with an intelligent decision support system (IDSS) based on fuzzy-logic. Our goal is to develop an assessment and training procedure that will result in improving handwriting taking the advantage of the force feedback provided by the haptic device and the intelligence provided by the IDSS. We also incorporate the inertia and viscosity effects to decrease the tremor in the hand as well as to stimulate the muscles involved in the task of holding a pencil (known as facilitation technique in the Occupational Therapy field). The IDSS is based upon a fuzzy automaton. By using qualitative (fuzzified) data from the previous tests executed by the subject, the system will make a decision on the complexity of the next test to be performed. It is expected that this automated system will reduce the burden and the associated cost of having a trained professional present in all assessment/training sessions.","PeriodicalId":197465,"journal":{"name":"2007 IEEE 10th International Conference on Rehabilitation Robotics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126754559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-06-13DOI: 10.1109/ICORR.2007.4428559
W. Ilg, R. Rorig, P. Thier, M. Giese
In this paper, we present learning-based methods for the analysis of the spatio-temporal characteristics of multidimensional movement trajectories. We show the application of these methods in two studies analyzing the influence of the cerebellum on intra-limb coordination and adaptation of gait for cerebellar patients.
{"title":"Learning-based methods for the analysis of intralimb-coordination and adaptation of locomotor patterns in cerebellar patients","authors":"W. Ilg, R. Rorig, P. Thier, M. Giese","doi":"10.1109/ICORR.2007.4428559","DOIUrl":"https://doi.org/10.1109/ICORR.2007.4428559","url":null,"abstract":"In this paper, we present learning-based methods for the analysis of the spatio-temporal characteristics of multidimensional movement trajectories. We show the application of these methods in two studies analyzing the influence of the cerebellum on intra-limb coordination and adaptation of gait for cerebellar patients.","PeriodicalId":197465,"journal":{"name":"2007 IEEE 10th International Conference on Rehabilitation Robotics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116036105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-06-13DOI: 10.1109/ICORR.2007.4428547
D. Reinkensmeyer, Jose A. Galvez, Laura Marchal, E. Wolbrecht, J. Bobrow
The field of robot-assisted movement therapy grew rapidly over the past ten years. In this paper we discuss three problems that the field will likely need to address in order to continue to flourish. These problems are to: 1) define the specific benefits of robotic actuation 2) increase the magnitude of functional benefits of robotic training; and 3) identify the mechanisms of motor learning in robot-manipulated environments. We review recent research in our laboratory that is addressing these problems. These projects are identifying motor learning tasks that robotic assistance can enhance, developing non-robotic technology when appropriate, and optimizing the forms of robotic assistance to the motor learning properties of humans.
{"title":"Some Key Problems for Robot-Assisted Movement Therapy Research: A Perspective from the University of California at Irvine","authors":"D. Reinkensmeyer, Jose A. Galvez, Laura Marchal, E. Wolbrecht, J. Bobrow","doi":"10.1109/ICORR.2007.4428547","DOIUrl":"https://doi.org/10.1109/ICORR.2007.4428547","url":null,"abstract":"The field of robot-assisted movement therapy grew rapidly over the past ten years. In this paper we discuss three problems that the field will likely need to address in order to continue to flourish. These problems are to: 1) define the specific benefits of robotic actuation 2) increase the magnitude of functional benefits of robotic training; and 3) identify the mechanisms of motor learning in robot-manipulated environments. We review recent research in our laboratory that is addressing these problems. These projects are identifying motor learning tasks that robotic assistance can enhance, developing non-robotic technology when appropriate, and optimizing the forms of robotic assistance to the motor learning properties of humans.","PeriodicalId":197465,"journal":{"name":"2007 IEEE 10th International Conference on Rehabilitation Robotics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116143086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-06-13DOI: 10.1109/ICORR.2007.4428419
G. Berselli, R. Falconi, G. Vassura, G. Modugno
Benign Paroxymal Positional Vertigo and variants, collectively called "vestibular lithiasis", designate a common disorder caused by a malfunction of the inner ear. These pathologies are connected with the presence of dense particles within the semicircular canals which interfere with the sensing capabilities of angular velocity in the patient, causing nystagmus and vertigo. Some of these conditions can be treated by repositioning maneuvers physically done by the doctor that moves the head of the patient along different poses in space. Despite the fact that the treatment shows a success rate up to 80-90%, the failure rate remains highly significant and it is proven that precision repeatability and unlimited 360deg manoeuvrability can improve diagnostic and treatment potential for overcoming this kind of vertigo. In this paper the kinematic design of a serial robot that will execute repositioning maneuvers automatically is performed through a simplified task based kinematic design technique. The aim of the method is to find the minimum number of degrees of freedom to carry out a set of given tasks as well as the manipulator's topology and the Denavit-Hartenberg parameters. The proposed procedure firstly minimizes the number of degrees of freedom only and then a cost function connected to the total link length.
{"title":"Task Based Kinematic Design of a Serial Robot for the Treatment of Vestibular Lithiasis","authors":"G. Berselli, R. Falconi, G. Vassura, G. Modugno","doi":"10.1109/ICORR.2007.4428419","DOIUrl":"https://doi.org/10.1109/ICORR.2007.4428419","url":null,"abstract":"Benign Paroxymal Positional Vertigo and variants, collectively called \"vestibular lithiasis\", designate a common disorder caused by a malfunction of the inner ear. These pathologies are connected with the presence of dense particles within the semicircular canals which interfere with the sensing capabilities of angular velocity in the patient, causing nystagmus and vertigo. Some of these conditions can be treated by repositioning maneuvers physically done by the doctor that moves the head of the patient along different poses in space. Despite the fact that the treatment shows a success rate up to 80-90%, the failure rate remains highly significant and it is proven that precision repeatability and unlimited 360deg manoeuvrability can improve diagnostic and treatment potential for overcoming this kind of vertigo. In this paper the kinematic design of a serial robot that will execute repositioning maneuvers automatically is performed through a simplified task based kinematic design technique. The aim of the method is to find the minimum number of degrees of freedom to carry out a set of given tasks as well as the manipulator's topology and the Denavit-Hartenberg parameters. The proposed procedure firstly minimizes the number of degrees of freedom only and then a cost function connected to the total link length.","PeriodicalId":197465,"journal":{"name":"2007 IEEE 10th International Conference on Rehabilitation Robotics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122678940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-06-13DOI: 10.1109/ICORR.2007.4428508
B. M. Wisse, W. van Dorsser, R. Barents, J. Herder
People with neuromuscular diseases often have limited muscle force, and many rely on mobile arm supports to move their arms. Most of these make use of static balancing, a useful concept to reduce the operating effort of mechanisms, where spring mechanisms are used to achieve a constant total potential energy, thus eliminating any preferred position. Once statically balanced, the mechanism can be moved virtually without operating energy. This allows the patients using an arm support to move their arms freely. In some cases it is desirable to adjust the balancer characteristic, for instance due to a change of payload when picking up an object. In all available arm support mechanisms this adjustment is associated with considerable mechanical effort, while clearly this application would benefit greatly from an energy-free adjustment. Recently several methods have been invented to adjust spring and linkage-based static balancers with no need for external energy, by conserving the total energy in the system. The technique discussed in this paper is based on substituting an initial spring by two substitute springs. The two substitute springs generate a virtual spring with the same spring properties as the initial spring, with one unique difference: the virtual spring can be elongated or shortened while no work is done. Consequently, no external energy is needed for the adjustment. A table-top demonstrator has been developed, showing the feasibility of the concept.
{"title":"Energy-Free Adjustment of Gravity Equilibrators Using the Virtual Spring Concept","authors":"B. M. Wisse, W. van Dorsser, R. Barents, J. Herder","doi":"10.1109/ICORR.2007.4428508","DOIUrl":"https://doi.org/10.1109/ICORR.2007.4428508","url":null,"abstract":"People with neuromuscular diseases often have limited muscle force, and many rely on mobile arm supports to move their arms. Most of these make use of static balancing, a useful concept to reduce the operating effort of mechanisms, where spring mechanisms are used to achieve a constant total potential energy, thus eliminating any preferred position. Once statically balanced, the mechanism can be moved virtually without operating energy. This allows the patients using an arm support to move their arms freely. In some cases it is desirable to adjust the balancer characteristic, for instance due to a change of payload when picking up an object. In all available arm support mechanisms this adjustment is associated with considerable mechanical effort, while clearly this application would benefit greatly from an energy-free adjustment. Recently several methods have been invented to adjust spring and linkage-based static balancers with no need for external energy, by conserving the total energy in the system. The technique discussed in this paper is based on substituting an initial spring by two substitute springs. The two substitute springs generate a virtual spring with the same spring properties as the initial spring, with one unique difference: the virtual spring can be elongated or shortened while no work is done. Consequently, no external energy is needed for the adjustment. A table-top demonstrator has been developed, showing the feasibility of the concept.","PeriodicalId":197465,"journal":{"name":"2007 IEEE 10th International Conference on Rehabilitation Robotics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122767592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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