-
[show abstract]
[hide abstract]
ABSTRACT: An upper limb stroke rehabilitation system is developed which combines electrical stimulation with mechanical arm support, to assist patients performing 3D reaching tasks in a virtual reality environment. The Stimulation Assistance through Iterative Learning (SAIL) platform applies electrical stimulation to two muscles in the arm using model-based control schemes which learn from previous trials of the task. This results in accurate movement which maximises the therapeutic effect of treatment. The principal components of the system are described and experimental results confirm its efficacy for clinical use in upper limb stroke rehabilitation.
Rehabilitation Robotics (ICORR), 2011 IEEE International Conference on; 08/2011
-
[show abstract]
[hide abstract]
ABSTRACT: An upper limb stroke rehabilitation system is developed which combines electrical stimulation with mechanical arm support, to assist patients performing 3D reaching tasks in a virtual reality environment. The Stimulation Assistance through Iterative Learning (SAIL) platform applies electrical stimulation to two muscles in the arm using model-based control schemes which learn from previous trials of the task. This results in accurate movement which maximises the therapeutic effect of treatment. The principal components of the system are described and experimental results confirm its efficacy for clinical use in upper limb stroke rehabilitation.
IEEE ... International Conference on Rehabilitation Robotics : [proceedings]. 06/2011; 2011:5975412.
-
[show abstract]
[hide abstract]
ABSTRACT: An inability to perform tasks involving reaching is a common problem for stroke patients. This paper provides an insight into mechanisms associated with recovery of upper limb function by examining how stroke participants' upper limb muscle activation patterns differ from those of neurologically intact participants, and how they change in response to an intervention. In this study, five chronic stroke participants undertook nine tracking tasks in which trajectory (orientation and length), speed and resistance to movement were varied. During these tasks, EMG signals were recorded from triceps, biceps, anterior deltoid, upper, middle and lower trapezius and pectoralis major. Data collection was performed in sessions both before, and after, an intervention in which participants performed a similar range of tracking tasks with the addition of responsive electrical stimulation applied to their triceps muscle. The intervention consisted of eighteen one hour treatment sessions, with two participants attending an additional seven sessions. During all sessions, each participant's arm was supported by a hinged arm-holder which constrained their hand to move in a two dimensional plane. Analysis of the pre intervention EMG data showed that timing and amplitude of peak EMG activity for all stroke participants differed from neurologically intact participants. Analysis of post intervention EMG data revealed that statistically significant changes in these quantities had occurred towards those of neurologically intact participants.
Journal of electromyography and kinesiology: official journal of the International Society of Electrophysiological Kinesiology 10/2009; 20(3):465-76. · 2.00 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: An overview is provided of the design, operation and performance of an experimental test facility that has been developed for stroke rehabilitation. The aim of the system is to improve sensory-motor function of the impaired upper limb, and it has recently been used in clinical trials with stroke participants. During treatment subjects were seated at the workstation and their impaired arm strapped to the robotic end-effector. Their task was to follow elliptical trajectories that were projected onto a target above their arm, using voluntary control with the addition of electrical stimulation mediated by advanced control schemes. The design of the experimental system is first summarised, and then details are presented of the modelling, identification and control techniques used by the workstation over the course of treatment.
Rehabilitation Robotics, 2009. ICORR 2009. IEEE International Conference on; 07/2009
-
[show abstract]
[hide abstract]
ABSTRACT: A summary is presented of the tracking and surface electromyographic (EMG) results obtained using a robotic workstation that was designed and built for use by stroke participants in order to improve voluntary control of their impaired arm. The intervention consisted of eighteen sessions in which five chronic stroke participants performed a range of tracking tasks using their remaining voluntary effort, with the addition of responsive electrical stimulation (ES) applied to their triceps muscles. Unassisted error tracking was measured during each intervention session. EMG, which may be related to impaired performance and function, was recorded in separate sessions before and after the intervention, in order to investigate changes in muscle activation patterns resulting from treatment. In these sessions, participants tracked similar trajectories without ES, and their muscle activity has been compared against that of eight neurologically intact subjects. Results are presented which describe changes in tracking ability and EMG, and their inter-relationship.
Rehabilitation Robotics, 2009. ICORR 2009. IEEE International Conference on; 07/2009
-
[show abstract]
[hide abstract]
ABSTRACT: An experimental test facility is developed for use by stroke patients in order to improve sensory-motor function of their upper limb. Subjects are seated at the workstation and their task is to repeatedly follow reaching trajectories that are projected onto a target above their arm. To do this they use voluntary control with the addition of electrical stimulation mediated by advanced control schemes applied to muscles in their impaired shoulder and arm. Full details of the design of the workstation and its periphery systems are given, together with a description of its use during the treatment of stroke patients.
Medical Engineering & Physics 04/2009; 31(3):364-73. · 1.62 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: An inability to perform tasks involving reaching is a common problem following stroke. Evidence supports the use of robotic therapy and functional electrical stimulation (FES) to reduce upper limb impairments, but current systems may not encourage maximal voluntary contribution from the participant because assistance is not responsive to performance.
This study aimed to investigate whether iterative learning control (ILC) mediated by FES is a feasible intervention in upper limb stroke rehabilitation.
Five hemiparetic participants with reduced upper limb function who were at least 6 months poststroke were recruited from the community. No participants withdrew.
Participants undertook supported tracking tasks using 27 different trajectories augmented by responsive FES to their triceps brachii muscle, with their hand movement constrained in a 2-dimensional plane by a robot. Eighteen 1-hour treatment sessions were used with 2 participants receiving an additional 7 treatment sessions.
The primary functional outcome measure was the Action Research Arm Test (ARAT). Impairment measures included the upper limb Fugl-Meyer Assessment (FMA), tests of motor control (tracking accuracy), and isometric force.
Compliance was excellent and there were no adverse events. Statistically significant improvements were measured (P <or= .05) in FMA motor score, unassisted tracking for 3 out of 4 trajectories, and in isometric force over 5 out of 6 directions. Changes in ARAT were not statistically significant.
This study has demonstrated the feasibility of using ILC mediated by FES for upper limb stroke rehabilitation.
Neurorehabilitation and neural repair 02/2009; 23(6):559-68. · 4.49 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: An inability to perform tasks involving reaching is a common problem for stroke patients. Knowledge of normal muscle activation patterns during these tasks is essential to the identification of abnormal patterns in post-stroke hemiplegia. Findings will provide insight into changes in muscle activation patterns associated with recovery of upper limb function. In this study with neurologically intact participants the co-ordination of shoulder and elbow muscle activity during two dimensional reaching tasks is explored. Eight participants undertook nine tracking tasks in which trajectory (orientation and length), duration, speed and resistance to movement were varied. The participants' forearm was supported using a hinged arm-holder, which constrained their hand to move in a two dimensional plane. EMG signals were recorded from triceps, biceps, anterior deltoid, upper, middle and lower trapezius and pectoralis major. A wide variation in muscle activation patterns, in terms of timing and amplitude, was observed between participants performing the same task. EMG amplitude increased significantly with length, duration and resistance of the task for all muscles except anterior deltoid. Co-activation between biceps and triceps was significantly dependent on both task and trajectory orientation. Activation pattern of pectoralis major was dependent on trajectory. Neither trajectory orientation nor task condition affected the activation pattern of anterior deltoid. Normal ranges of timing of muscle activity during the tasks were identified.
Journal of electromyography and kinesiology: official journal of the International Society of Electrophysiological Kinesiology 01/2009; 19(6):1025-34. · 2.00 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A summary of the design and functionality of a robotic workstation that has been constructed for use by stroke patients in order to improve voluntary control of their impaired arm is first given in this paper. The patient's task will be to track an elliptical trajectory using voluntary control with the addition of surface FES applied to muscles in their shoulder and arm. This work then comprises results of a preliminary study to this project in which unimpaired subjects track a series of trajectories using, firstly, only voluntary action, and secondly, using stimulation applied to their triceps muscle only, and with no voluntary control. Results obtained from the study of EMG signals relating to the former case illustrate the activation patterns generated when performing the reaching tasks and confirm the choice of muscles that will be stimulated in the main study. Experimental results from the latter tests are then presented to highlight the performance that can be achieved when using only the application of FES to accomplish the reaching tasks.
Rehabilitation Robotics, 2007. ICORR 2007. IEEE 10th International Conference on; 07/2007
-
[show abstract]
[hide abstract]
ABSTRACT: This paper describes the experimental test facility that has been designed as part of a current project whose aim is to investigate the use of iterative learning control (ILC) and related strategies to mediate the electrical stimulation applied to a number of muscles of the shoulder and upper limb of stroke patients. ILC is a technique that has its origins in the area of industrial robotics and is especially targeted at systems operating in a repetitive mode with the additional requirement that a specified output trajectory over a finite interval (or trial) is followed to a specified level of precision. Motivated by human learning, the basic idea of ILC is to use information from previous executions of the task in order to improve performance from trial to trial. In the context of this work, ILC offers the opportunity of allowing the user to learn how to perfect a given task by controlling the amount of additional stimulation applied from one trial to the next. If this has been achieved, then further refinement is possible to reduce the stimulation effort supplied by the control scheme and thereby increase the effort necessary from the subject. In particular, ILC requires a basic representation of the underlying (dynamic) relationship between stimulation (or input) and response (or output) and also the specification of a target (or reference) trajectory to form the goal for the ILC scheme to achieve
UKACC Control, 2006. Mini Symposia; 10/2006
-
[show abstract]
[hide abstract]
ABSTRACT: A model of the upper limb is developed in which
the forearm is constrained to lie in a horizontal plane and electrical
stimulation is applied to the triceps muscle. Identification
procedures are described to estimate the unknown parameters
using a small number of tests. Examples of identified parameters
obtained experimentally are presented for both stroke
patients and unimpaired subjects. The model has been used to
derive controllers which have been applied during clinical trials
to reduce the level of impairment of stroke patients.
-
-
[show abstract]
[hide abstract]
ABSTRACT: There is a body of clinical evidence to support the use of FES to improve motor control (De Kroon et al. 2002) and theoretical support from neurophysiology (Burridge & Ladouceur 2001) and motor learning research (Schmidt & Lee 1999). Iterative learning control has its origins in the control of processes that repetitively perform a task with a view to improving accuracy. The classic example is the area of trajectory following in robotics but can it be usefully applied to neurological rehabilitation?
-
[show abstract]
[hide abstract]
ABSTRACT: A control system for stroke rehabilitation is developed which combines electrical stimulation with a robotic support system to provide assistance to stroke patients performing 3D upper limb reaching tasks in a virtual reality environment. The electrical stimulation is applied to two muscles in the subject's arm using the phase-lead iterative learning control schemes which learn from previous trials of the task in order to achieve highly accurate movement. The principal components of the system are described and experimental results confirm its feasibility and efficiency for use in upper limb stroke rehabilitation.
-
[show abstract]
[hide abstract]
ABSTRACT: The concept of ‘learned disuse’ is thought to be a significant barrier to recovery of sensory-motor function following a stroke. Unimpaired individuals learn new skills though practice, with feedback in various forms, but the problem facing the stroke patient is that they are unable to practice because of impaired motor control. Functional electrical stimulation (FES) can provide the experience for the patient of moving and consequently may limit the problem of learnt disuse and has been used with some success to improve recovery of upper limb motor control. Recent studies have shown that when stimulation is associated with a voluntary attempt to move the limb, improvement is enhanced but these techniques do not allow feedback that could be used to adjust stimulation parameters and thus provide more precise stimulation.
This paper describes the design and construction of an experimental test facility that has been designed as part of a current project whose aim is to investigate the use of iterative learning control (ILC) and related strategies to mediate the electrical stimulation applied to a number of muscles of the shoulder and upper limb of stroke patients.
-
[show abstract]
[hide abstract]
ABSTRACT: A summary of the design and functionality of a robotic workstation that has been constructed for use by stroke patients in order to improve voluntary control of their impaired arm is first given in this paper. The patient’s task will be to track an elliptical trajectory using voluntary control with the addition of surface FES applied to muscles in their shoulder and arm. This work then comprises results of a preliminary study
to this project in which unimpaired subjects track a series of trajectories using, firstly, only voluntary action, and secondly, using stimulation applied to their triceps muscle only, and with no voluntary control. Results obtained from the study of EMG
signals relating to the former case illustrate the activation patterns generated when performing the reaching tasks and confirm the choice of muscles that will be stimulated in the main study. Experimental results from the latter tests are then presented to highlight the performance that can be achieved when using only the application of FES to accomplish the reaching tasks.
-
[show abstract]
[hide abstract]
ABSTRACT: Robots (Prange et al 2007) and FES can improve impairment levels and possibly function (De Kroon et al. 2002), (Burridge & Ladouceur 2001) of the upper limb post stroke.
This study investigates the feasibility of using ILC mediated by FES to extend the ability of a stroke patient to perform a two dimensional tracking task with their arm supported by a robot arm. Iterative learning control reduces the error between the actual and desired trajectory during repeated performances of a reaching task by adjusting the level of FES. Preliminary tests to identify which muscles are active during this task and when were performed with neurologically intact participants.
-
[show abstract]
[hide abstract]
ABSTRACT: The UK Stroke Guidelines suggest “Robot-assisted movement therapy should be considered as an adjunct to conventional therapy” for chronic patients with a deficit in arm function (Intercollegiate working Party for Stroke, 2004).
Our interdisciplinary study funded by EPSRC (EP/C51873X/1) aims to investigate the feasibility of using Iterative Learning Control mediated by electrical stimulation for upper limb rehabilitation post stroke. The objective is to extend the patient’s ability to perform tasks with their arm, supported by the robot. By adjusting the level of stimulation in response to their performance, tasks are altered so that patients are always working at their limit – while motivated by their success. As a background to this study a review was conducted to explore the role of robots in upper limb post stroke therapy.
-
[show abstract]
[hide abstract]
ABSTRACT: An overview is provided of the design, operation and performance of an experimental test facility that has been developed for stroke rehabilitation. The aim of the system is to improve sensory-motor function of the impaired upper limb, and it has recently been used in clinical trials with stroke participants. During treatment subjects were seated at the workstation and their impaired arm strapped to the robotic end-effector. Their task was to follow elliptical trajectories that were projected onto a target above their arm, using voluntary control with the addition of electrical stimulation mediated by advanced control schemes. The design of the experimental system is first summarised, and then details are presented of the modelling, identification and control techniques used by the workstation over the course of treatment.
-
[show abstract]
[hide abstract]
ABSTRACT: A summary is presented of the tracking and surface electromyographic (EMG) results obtained using a robotic workstation that was designed and built for use by stroke participants in order to improve voluntary control of their impaired arm. The intervention consisted of eighteen sessions in which five chronic stroke participants performed a range of tracking tasks using their remaining voluntary effort, with the addition of responsive electrical stimulation (ES) applied to their triceps muscles. Unassisted error tracking was measured during each intervention session. EMG, which may be related to impaired performance and function, was recorded in separate sessions before and after the intervention, in order to investigate changes in muscle activation patterns resulting from treatment. In these sessions, participants tracked similar trajectories without ES, and their muscle activity has been compared against that of eight neurologically intact subjects. Results are presented which describe changes in tracking ability and EMG, and their inter-relationship.
