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Biomedical subjects

Neville Hogan

Publications and source records attributed to Neville Hogan.

10 recordsLinked to original sources

Robotics and other devices in the treatment of patients recovering from stroke.

Stroke is the leading cause of permanent disability in the United States despite advances in prevention and novel interventional treatments. Randomized controlled studies have demonstrated the effectiveness of specialized post-stroke rehabilitation units, but administrative orders have severely limited the length of stay, so novel approaches to the treatment of recovery need to be tested in outpatients. Although the mechanisms of stroke recovery depend on multiple factors, a number of techniques that concentrate on enhanced exercise of the paralyzed limb have demonstrated effectiveness in reducing the motor impairment. For example, interactive robotic devices are new tools for therapists to deliver enhanced sensorimotor training for the paralyzed upper limb, which can potentially improve patient outcome and increase their productivity. New data support the idea that for some post-stroke patients and for some aspects of training-induced recovery, timing of the training may be less important than the quality and intensity of the training. The positive outcome that resulted in the interactive robotic trials contrasts with the failure to find a beneficial result in trials that used a noninteractive device that delivered continuous passive motion only. New pilot data from novel devices to move the wrist demonstrate benefit and suggest that successive improvement of the function of the arm progressing to the distal muscles may eventually lead to significant disability reduction. These data from robotic trials continue to contribute to the emerging scientific basis of neuro-rehabilitation.

Equipment Design↗

Robotic therapy for chronic motor impairments after stroke: Follow-up results.

OBJECTIVES: To study the effects of robotic rehabilitation in persons with chronic motor impairments after stroke and to examine whether improvements in motor abilities were sustained 4 months after the end of therapy. DESIGN: Pretest-posttest design. SETTING: Rehabilitation hospital, outpatient care. PARTICIPANTS: Volunteer sample of 42 persons with persistent hemiparesis from a single, unilateral stroke within the past 1 to 5 years. INTERVENTION: Robotic therapy for the paretic upper limb consisted of either sensorimotor active-assistive exercise, or progressive-resistive training during repetitive, planar reaching tasks, 3 times a week for 6 weeks. MAIN OUTCOME MEASURES: Modified Ashworth Scale, Fugl-Meyer Assessment (FMA), Motor Status Scale (MSS) score, and Medical Research Council motor power score. RESULTS: No significant differences were found among pretreatment clinical evaluations. Statistically significant gains from admission to discharge and from admission to follow-up (P<.05) were found on the FMA, MSS score for shoulder and elbow, and motor power score. CONCLUSIONS: Short-term, goal-directed robotic therapy can significantly improve motor abilities of the exercised limb segments in persons with chronic stroke that are sustained 4 months after discharge. This suggests that motor recovery can be enhanced by repetitive exercise training more than 1 year after stroke.

Adult↗

Comparison of two techniques of robot-aided upper limb exercise training after stroke.

OBJECTIVE: This study examined whether incorporating progressive resistive training into robot-aided exercise training provides incremental benefits over active-assisted robot-aided exercise for the upper limb after stroke. DESIGN: A total of 47 individuals at least 1 yr poststroke were enrolled in this 6-wk training protocol. Paretic upper limb motor abilities were evaluated using clinical measures and a robot-based assessment to determine eligibility for robot-aided progressive resistive training at study entry. Subjects capable of participating in resistance training were randomized to receive either active-assisted robot-aided exercises or robot-aided progressive resistance training. Subjects who were incapable of participating in resistance training underwent active-assisted robotic therapy and were again screened for eligibility after 3 wks of robotic therapy. Those subjects capable of participating in resistance training at 3 wks were then randomized to receive either robot-aided resistance training or to continue with robot-aided active-assisted training. RESULTS: One subject withdrew due to unrelated medical issues, and data for the remaining 46 subjects were analyzed. Subjects in all groups showed improvement in measures of motor control (mean increase in Fugl-Meyer of 3.3; 95% confidence interval, 2.2-4.4) and maximal force (mean increase in maximal force of 3.5 N, P = 0.027) over the course of robot-aided exercise training. No differences in outcome measures were observed between the resistance training groups and the matched active-assisted training groups. Subjects' ability to perform the robotic task at the time of group assignment predicted the magnitude of the gain in motor control. CONCLUSION: The incorporation of robot-aided progressive resistance exercises into a program of robot-aided exercise did not favorably or negatively affect the gains in motor control or strength associated with this training, though interpretation of these results is limited by sample size. Individuals with better motor control at baseline experienced greater increases in motor control with robotic training.

Adult↗

Does shorter rehabilitation limit potential recovery poststroke?

OBJECTIVE: To examine retrospectively the recovery of patients engaged in robotic research during a 6 to 7-week course of inpatient rehabilitation. Because timing of the Interim evaluation at 3 1/2 weeks was comparable to the present length of inpatient stroke rehabilitation, the authors assessed whether significant gains in motor abilities occurred after the time when most stroke patients today are discharged home. METHODS: Fifty-six inpatients with a single, unilateral stroke were randomly assigned to a robot therapy or robot exposure group. Therapists blinded to group assignment administered the Fugl-Meyer, Motor Status Score, and MRC motor power test. RESULTS: Significant improvements in upper-limb motor abilities occurred throughout a period approximately twice the present length of stay in inpatient rehabilitation. However, in the latter half of this period, patients who received conventional therapy showed little improvement, whereas patients who received robot training plus conventional therapy continued to improve. CONCLUSION: Further opportunities for recovery after stroke are possible by extending intensive therapy beyond present inpatient rehabilitation stays.

Adult↗

Avoiding spurious submovement decompositions: a globally optimal algorithm.

Evidence for the existence of discrete submovements underlying continuous human movement has motivated many attempts to "extract" them. Although they produce visually convincing results, all of the methodologies that have been employed are prone to produce spurious decompositions. Examples of potential failures are given. A branch-and-bound algorithm for submovement extraction, capable of global nonlinear minimization (and hence capable of avoiding spurious decompositions), is developed and demonstrated.

Algorithms↗

Effects of robotic therapy on motor impairment and recovery in chronic stroke.

OBJECTIVE: To examine whether robotic therapy can reduce motor impairment and enhance recovery of the hemiparetic arm in persons with chronic stroke. DESIGN: Pre-posttest design. SETTING: Rehabilitation hospital, outpatient care. PARTICIPANTS: Volunteer sample of 20 persons diagnosed with a single, unilateral stroke within the past 1 to 5 years, with persistent hemiparesis. INTERVENTIONS: Robotic therapy was provided 3 times weekly for 6 weeks. Subjects able to reach robot targets were randomly assigned to sensorimotor or progressive-resistive robotic therapy groups. Robotic therapy consisted of goal-directed, planar reaching tasks to exercise the hemiparetic shoulder and elbow. MAIN OUTCOME MEASURES: The Modified Ashworth Scale, Fugl-Meyer test of upper-extremity function, Motor Status Scale (MSS) score, and Medical Research Council motor power score. RESULTS: Evaluations by a single blinded therapist revealed statistically significant gains from admission to discharge (P<.05) on the Fugl-Meyer test, MSS score, and motor power score. Secondary analyses revealed group differences: the progressive-resistive therapy group experienced nonspecific improvements on wrist and hand MSS scores that were not observed in the sensorimotor group. CONCLUSIONS: Robotic therapy may complement other treatment approaches by reducing motor impairment in persons with moderate to severe chronic impairments.

Adult↗

Robot-aided sensorimotor training in stroke rehabilitation.

The first groups to use robotic devices to enhance the sensorimotor experience of patients recovering from upper limb paralysis after stroke have generated encouraging information. Patient acceptance and staff enthusiasm for robot training at Burke--MIT is consistently high. Robot training data are consistent with other controlled studies showing that more activity leads to more motor improvement and decreased impairment. Therapists equipped with a robotic device can increase the amount and intensity of movement of the paralyzed limb without sacrificing time spent training complex functionally appropriate kinematics.

Arm↗

Movement smoothness changes during stroke recovery.

Smoothness is characteristic of coordinated human movements, and stroke patients' movements seem to grow more smooth with recovery. We used a robotic therapy device to analyze five different measures of movement smoothness in the hemiparetic arm of 31 patients recovering from stroke. Four of the five metrics showed general increases in smoothness for the entire patient population. However, according to the fifth metric, the movements of patients with recent stroke grew less smooth over the course of therapy. This pattern was reproduced in a computer simulation of recovery based on submovement blending, suggesting that progressive blending of submovements underlies stroke recovery.

Acceleration↗

Robotics in the rehabilitation treatment of patients with stroke.

Stroke is the leading cause of permanent disability despite continued advances in prevention and novel interventional treatments. Post-stroke neuro-rehabilitation programs teach compensatory strategies that alter the degree of permanent disability. Robotic devices are new tools for therapists to deliver enhanced sensorimotor training and concentrate on impairment reduction. Results from several groups have registered success in reducing impairment and increasing motor power with task-specific exercise delivered by the robotic devices. Enhancing the rehabilitation experience with task-specific repetitive exercise marks a different approach to the patient with stroke. The clinical challenge will be to streamline, adapt, and expand the robot protocols to accommodate healthcare economies, to determine which patients sustain the greatest benefit, and to explore the relationship between impairment reduction and disability level. With these new tools, therapists will measure aspects of outcome objectively and contribute to the emerging scientific basis of neuro-rehabilitation.

Bionics↗

Serial processing in human movement production.

Parallel processing is often considered to be synonymous with biological computation, but a great deal of evidence points to serial computation being used by animals to solve specific types of problems. In particular, the observation of movement intermittency (fluctuations in limb kinematic variables that cannot be explained by low-level dynamics of the system) seems to imply a serial temporal segmentation strategy in the planning of arm movements. This paper discusses prior observations of movement intermittency in different task contexts, possible theoretical and physiological origins of the phenomenon, and implications for human movement strategies.

Journal Article↗