xuan kang - Academia.edu (original) (raw)
Papers by xuan kang
2010 3rd IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics, 2010
Chronic hand impairment is common following stroke. While mass practice of movement has shown pro... more Chronic hand impairment is common following stroke. While mass practice of movement has shown promise for rehabilitation, initial impairment of the hand may be too severe to permit even approximations of the desired movement. To facilitate movement, especially of pinch, we are building an exoskeleton to permit independent actuation of each of the three joints of the index finger. Separate actuators are used for flexion and extension, with closed-loop control of either force or position. In the future, a companion thumb exoskeleton will be developed to permit coordinated performance of pinch. This system will be used to assess strategies for optimizing rehabilitation of pinch and reach-to-pinch following stroke. The design of the actuated index finger exoskeleton is presented here. I. INTRODUCTION and impairment is a prevalent outcome for a variety of neuromuscular disorders, such as stroke. Upwards of 700,000 people in the U.S. experience a stroke each year [1]. Of these, 60-75% will live beyond one year after incidence, resulting in a current stroke population of 3 million [2-4]. Arm function is acutely impaired in a large majority of those diagnosed with stroke [5-7]. Furthermore, acute hemiparesis presages chronic hemiparesis in over 40°0 of the cases [5, 6]. Chronic deficits are especially prevalent in the distal upper extremities. In fact, finger extension is the motor function most often impaired [8]. This distal limb impairment is especially problematic, because proper hand function is crucial to manual exploration and manipulation of the environment. Indeed, loss of hand function is a major source of disability in neuromuscular disorders, frequently preventing effective self-care and limiting employment opportunities. One study in the UK reported that more than half of the subjects Manuscript received February 11, 2007. This work was supported in part by the Davee Foundation and the Coleman Foundation.
2011 IEEE International Conference on Robotics and Automation, 2011
Neurologic Clinics
Motor neuron diseases involve degeneration of motor neurons in the brain (upper motor neurons), b... more Motor neuron diseases involve degeneration of motor neurons in the brain (upper motor neurons), brain stem, and spinal cord (lower motor neurons). Symptoms vary depending on the degree of upper and lower neuron involvement, but progressive painless weakness is the predominant complaint. Motor neuron disease includes numerous specific disorders, including amyotrophic lateral sclerosis, spinal muscular atrophy, spinal bulbar muscular atrophy, and other inherited and acquired conditions. Abnormalities on nerve conduction studies, repetitive nerve stimulation, needle electromyography, and other electrodiagnostic techniques help to distinguish these disorders from each other, and from other disorders with progressive weakness.
Scientific Reports
In this study, we applied high-density EEG recordings (HD-EEG) to quantitatively characterize the... more In this study, we applied high-density EEG recordings (HD-EEG) to quantitatively characterize the fine-grained spatiotemporal distribution of inter-ictal epileptiform discharges (IEDs) across different sleep stages. We quantified differences in spatial extent and duration of IEDs at the scalp and cortical levels using HD-EEG source-localization, during non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep, in six medication-refractory focal epilepsy patients during epilepsy monitoring unit admission. Statistical analyses were performed at single subject level and group level across different sleep stages for duration and distribution of IEDs. Tests were corrected for multiple comparisons across all channels and time points. Compared to NREM sleep, IEDs during REM sleep were of significantly shorter duration and spatially more restricted. Compared to NREM sleep, IEDs location in REM sleep also showed a higher concordance with electrographic ictal onset zone from scal...
Journal of Child Neurology
Stormorken syndrome is a rare genetic disorder (MIM 185070) first reported in 1983 with thrombocy... more Stormorken syndrome is a rare genetic disorder (MIM 185070) first reported in 1983 with thrombocytopenia, muscle weakness, asplenia, and miosis caused by a mutation of the stromal interaction molecule 1 ( STIM1) gene.1 The muscle weakness is caused by a myopathy with tubular aggregate formation. We report a family in which both child and mother presented with proximal muscle weakness and thrombocytopenia. Histologic, histochemical, and electron microscopy studies were performed on the muscle specimen. It documented accumulation of tubular aggregates and chronic myopathic changes with dystrophic features. Genetic testing revealed that both mother and son carried a missense mutation of c.326A>G in exon 3 of the STIM1 gene, which is novel for Stormorken syndrome. We suggest that patients with unexplained chronic idiopathic thrombocytopenia and proximal weakness have genetic testing for Stormorken syndrome.
Topics in Stroke …, 2011
The purpose of this study was to investigate the influence of prolonged and repetitive passive ra... more The purpose of this study was to investigate the influence of prolonged and repetitive passive range of motion (PROM) stretching of the fingers on hand function in stroke survivors. Fifteen chronic stroke survivors with moderate to severe hand impairment took part in the study. Participants underwent 3 experimental sessions consisting of 30 minutes of rest, prolonged, or repetitive stretching of the finger flexor muscles by a powered glove orthosis (X-Glove). Outcome measures, comprised of 3 selected tasks from the Graded Wolf Motor Function Test (GWMFT), grip strength, lateral pinch strength, and grip relaxation time, were recorded at the start and end of each session. Change in outcome score for each session was used for analysis. Data suggested a trend for improvement following stretching, especially for the repetitive PROM case. For one GWMFT task (lift washcloth), the effect of stretching condition on performance time approached a statistical significance (P = .015), with repetitive PROM stretching producing the greatest mean reduction. Similarly, repetitive stretching led to a 12% ± 16% increase in grip strength, although this change was not statistically different across groups (P = .356); and grip termination time was reduced, albeit non-significantly, by 66% ± 133%. Repetitive PROM stretching exhibited trends to be more effective than prolonged stretching for improving hand motor control. Although the results were highly variable and the effects are undoubtedly transient, an extended period of repetitive PROM stretching may prove advantageous prior to hand therapy sessions to maximize treatment.
2010 3rd IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics, 2010
Chronic hand impairment is common following stroke. While mass practice of movement has shown pro... more Chronic hand impairment is common following stroke. While mass practice of movement has shown promise for rehabilitation, initial impairment of the hand may be too severe to permit even approximations of the desired movement. To facilitate movement, especially of pinch, we are building an exoskeleton to permit independent actuation of each of the three joints of the index finger. Separate actuators are used for flexion and extension, with closed-loop control of either force or position. In the future, a companion thumb exoskeleton will be developed to permit coordinated performance of pinch. This system will be used to assess strategies for optimizing rehabilitation of pinch and reach-to-pinch following stroke. The design of the actuated index finger exoskeleton is presented here. I. INTRODUCTION and impairment is a prevalent outcome for a variety of neuromuscular disorders, such as stroke. Upwards of 700,000 people in the U.S. experience a stroke each year [1]. Of these, 60-75% will live beyond one year after incidence, resulting in a current stroke population of 3 million [2-4]. Arm function is acutely impaired in a large majority of those diagnosed with stroke [5-7]. Furthermore, acute hemiparesis presages chronic hemiparesis in over 40°0 of the cases [5, 6]. Chronic deficits are especially prevalent in the distal upper extremities. In fact, finger extension is the motor function most often impaired [8]. This distal limb impairment is especially problematic, because proper hand function is crucial to manual exploration and manipulation of the environment. Indeed, loss of hand function is a major source of disability in neuromuscular disorders, frequently preventing effective self-care and limiting employment opportunities. One study in the UK reported that more than half of the subjects Manuscript received February 11, 2007. This work was supported in part by the Davee Foundation and the Coleman Foundation.
2011 IEEE International Conference on Robotics and Automation, 2011
Neurologic Clinics
Motor neuron diseases involve degeneration of motor neurons in the brain (upper motor neurons), b... more Motor neuron diseases involve degeneration of motor neurons in the brain (upper motor neurons), brain stem, and spinal cord (lower motor neurons). Symptoms vary depending on the degree of upper and lower neuron involvement, but progressive painless weakness is the predominant complaint. Motor neuron disease includes numerous specific disorders, including amyotrophic lateral sclerosis, spinal muscular atrophy, spinal bulbar muscular atrophy, and other inherited and acquired conditions. Abnormalities on nerve conduction studies, repetitive nerve stimulation, needle electromyography, and other electrodiagnostic techniques help to distinguish these disorders from each other, and from other disorders with progressive weakness.
Scientific Reports
In this study, we applied high-density EEG recordings (HD-EEG) to quantitatively characterize the... more In this study, we applied high-density EEG recordings (HD-EEG) to quantitatively characterize the fine-grained spatiotemporal distribution of inter-ictal epileptiform discharges (IEDs) across different sleep stages. We quantified differences in spatial extent and duration of IEDs at the scalp and cortical levels using HD-EEG source-localization, during non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep, in six medication-refractory focal epilepsy patients during epilepsy monitoring unit admission. Statistical analyses were performed at single subject level and group level across different sleep stages for duration and distribution of IEDs. Tests were corrected for multiple comparisons across all channels and time points. Compared to NREM sleep, IEDs during REM sleep were of significantly shorter duration and spatially more restricted. Compared to NREM sleep, IEDs location in REM sleep also showed a higher concordance with electrographic ictal onset zone from scal...
Journal of Child Neurology
Stormorken syndrome is a rare genetic disorder (MIM 185070) first reported in 1983 with thrombocy... more Stormorken syndrome is a rare genetic disorder (MIM 185070) first reported in 1983 with thrombocytopenia, muscle weakness, asplenia, and miosis caused by a mutation of the stromal interaction molecule 1 ( STIM1) gene.1 The muscle weakness is caused by a myopathy with tubular aggregate formation. We report a family in which both child and mother presented with proximal muscle weakness and thrombocytopenia. Histologic, histochemical, and electron microscopy studies were performed on the muscle specimen. It documented accumulation of tubular aggregates and chronic myopathic changes with dystrophic features. Genetic testing revealed that both mother and son carried a missense mutation of c.326A>G in exon 3 of the STIM1 gene, which is novel for Stormorken syndrome. We suggest that patients with unexplained chronic idiopathic thrombocytopenia and proximal weakness have genetic testing for Stormorken syndrome.
Topics in Stroke …, 2011
The purpose of this study was to investigate the influence of prolonged and repetitive passive ra... more The purpose of this study was to investigate the influence of prolonged and repetitive passive range of motion (PROM) stretching of the fingers on hand function in stroke survivors. Fifteen chronic stroke survivors with moderate to severe hand impairment took part in the study. Participants underwent 3 experimental sessions consisting of 30 minutes of rest, prolonged, or repetitive stretching of the finger flexor muscles by a powered glove orthosis (X-Glove). Outcome measures, comprised of 3 selected tasks from the Graded Wolf Motor Function Test (GWMFT), grip strength, lateral pinch strength, and grip relaxation time, were recorded at the start and end of each session. Change in outcome score for each session was used for analysis. Data suggested a trend for improvement following stretching, especially for the repetitive PROM case. For one GWMFT task (lift washcloth), the effect of stretching condition on performance time approached a statistical significance (P = .015), with repetitive PROM stretching producing the greatest mean reduction. Similarly, repetitive stretching led to a 12% ± 16% increase in grip strength, although this change was not statistically different across groups (P = .356); and grip termination time was reduced, albeit non-significantly, by 66% ± 133%. Repetitive PROM stretching exhibited trends to be more effective than prolonged stretching for improving hand motor control. Although the results were highly variable and the effects are undoubtedly transient, an extended period of repetitive PROM stretching may prove advantageous prior to hand therapy sessions to maximize treatment.