Yee Sien Ng

Facilitating Effects of Transcranial Direct Current Stimulation on Motor Imagery Brain-Computer Interface With Robotic Feedback for Stroke Rehabilitation

OBJECTIVE To investigate the efficacy and effects of transcranial direct current stimulation (tDCS) on motor imagery brain-computer interface (MI-BCI) with robotic feedback for stroke rehabilitation. DESIGN A sham-controlled, randomized controlled trial. SETTING Patients recruited through a hospital stroke rehabilitation program. PARTICIPANTS Subjects (N=19) who incurred a stroke 0.8 to 4.3 years prior, with moderate to severe upper extremity functional impairment, and passed BCI screening. INTERVENTIONS Ten sessions of 20 minutes of tDCS or sham before 1 hour of MI-BCI with robotic feedback upper limb stroke rehabilitation for 2 weeks. Each rehabilitation session comprised 8 minutes of evaluation and 1 hour of therapy. MAIN OUTCOME MEASURES Upper extremity Fugl-Meyer Motor Assessment (FMMA) scores measured end-intervention at week 2 and follow-up at week 4, online BCI accuracies from the evaluation part, and laterality coefficients of the electroencephalogram (EEG) from the therapy part of the 10 rehabilitation sessions. RESULTS FMMA score improved in both groups at week 4, but no intergroup differences were found at any time points. Online accuracies of the evaluation part from the tDCS group were significantly higher than those from the sham group. The EEG laterality coefficients from the therapy part of the tDCS group were significantly higher than those of the sham group. CONCLUSIONS The results suggest a role for tDCS in facilitating motor imagery in stroke.

Mechanical design of a portable knee-ankle-foot robot

We are developing an intelligent compact and modular knee-ankle-foot robot gait rehabilitation at outpatient and home settings. The robot is designed with a novel compact compliant force controllable actuator. We adopt a modular design for the knee and ankle joint so that the robot can assist patients with different conditions of gait impairments. The light-weight anthropomorphic structure designed based on biomechanical studies is built with advanced composite materials to achieve portability. A prototype of the robot has been built for testing. In this paper, we present the mechanical design of the robot with focus on the actuator and mechanism design and analysis, with testing results to demonstrate the performance of the actuator.

The synergistic effect of functional status and comorbidity burden on mortality: a 16-year survival analysis.

Objectives The relationship between disability and comorbidity on mortality is widely perceived as additive in clinical models of frailty. Design National data were retrospectively extracted from medical records of community hospital. Data Sources There were of 12,804 acutely-disabled patients admitted for inpatient rehabilitation in Singapore rehabilitation community hospitals from 1996 through 2005 were followed up for death till 31 December 2011. Outcome Measure Cox proportional-hazards regression to assess the interaction of comorbidity and disability at discharge on all-cause mortality. Results During a median follow-up of 10.9 years, there were 8,565 deaths (66.9%). The mean age was 73.0 (standard deviation: 11.5) years. Independent risk factors of mortality were higher comorbidity (p<0.001), severity of disability at discharge (p<0.001), being widowed (adjusted hazard ratio [aHR]: 1.38, 95% confidence interval [CI]:1.25–1.53), low socioeconomic status (aHR:1.40, 95%CI:1.29–1.53), discharge to nursing home (aHR:1.14, 95%CI:1.05–1.22) and re-admission into acute care (aHR:1.54, 95%CI:1.45–1.65). In the main effects model, those with high comorbidity had an aHR = 2.41 (95%CI:2.13–2.72) whereas those with total disability had an aHR = 2.28 (95%CI:2.12–2.46). In the interaction model, synergistic interaction existed between comorbidity and disability (p<0.001) where those with high comorbidity and total disability had much higher aHR = 6.57 (95%CI:5.15–8.37). Conclusions Patients with greater comorbidity and disability at discharge, discharge to nursing home or re-admission into acute care, lower socioeconomic status and being widowed had higher mortality risk. Our results identified predictive variables of mortality that map well onto the frailty cascade model. Increasing comorbidity and disability interacted synergistically to increase mortality risk.

Impedance control of a rehabilitation robot for interactive training

In this paper, neural networks based impedance control is developed for a wearable rehabilitation robot in interactions with humans and the environments. The dynamics of the robot are represented by an n-link rigid robotic manipulator. To deal with the system uncertainties and improve the robustness of the system, the adaptive neural networks are used to approximate the unknown model of the constrained robot. With the proposed control, uniform ultimate boundedness of the closed loop system is achieved based on the Lyapunov method. The states of the system converge to a small neighborhood of zero by properly choosing control gains. Extensive simulations are conducted to verify the proposed control.

A Smartphone-Centric System for the Range of Motion Assessment in Stroke Patients

The range of motion (ROM) in stroke patients is often severely affected. Poststroke rehabilitation is guided through the use of clinical assessment scales for the rROM. Unfortunately, these scales are not widely utilized in clinical practice as they are excessively time-consuming. Although commercial motion-capture systems are capable of providing the information required for the assessments, most systems are either too costly or lack the convenience required for assessments to be conducted on a daily basis. This paper presents the design and implementation of a smartphone-based system for automated motor assessment using low-cost off-the-shelf inertial sensors. The system was used to automate a portion of the upper-extremity Fugl-Meyer assessment (FMA), which is widely used to quantify motor deficits in stroke survivors. Twelve out of 33 items were selected, focusing mainly on joint angle measurements of the upper body. The system has the ability to automatically identify the assessment item being conducted, and calculate the maximum respective joint angle achieved. Preliminary results show the ability of this system to achieve comparable results to goniometer measurements, while significantly reducing the time required to conduct the assessments. The portability and ease-of-use of the system would simplify the task of conducting range-of-motion assessments.

Impact of a viral respiratory epidemic on the practice of medicine and rehabilitation: severe acute respiratory syndrome.

Lim PA, Ng YS, Tay BK. Impact of a viral respiratory epidemic on the practice of medicine and rehabilitation: severe acute respiratory syndrome. Arch Phys Med Rehabil 2004;85:1365–70. Severe acute respiratory syndrome (SARS) is a new respiratory viral epidemic that originated in China but has affected many parts of the world, with devastating impact on economies and the practice of medicine and rehabilitation. A novel coronavirus has been implicated, with transmission through respiratory droplets. Rehabilitation was significantly affected by SARS, because strict infection control measures run counter to principles such as multidisciplinary interactions, patients encouraging and learning from each other, and close physical contact during therapy. Immunocompromised patients who may silently carry SARS are common in rehabilitation and include those with renal failure, diabetes, and cancer. Routine procedures such as management of feces and respiratory secretions (eg, airway suctioning, tracheotomy care) have been classified as high risk. Personal protection equipment presented not only a physical but also a psychologic barrier to therapeutic human contact. Visitor restriction to decrease chances of disease transmission are particularly difficult for long-staying rehabilitation patients. At the height of the epidemic, curtailment of patient movement stopped all transfers for rehabilitation, and physiatrists had to function as general internists. Our experiences strongly suggest that rehabilitation institutions should have emergency preparedness plans because such epidemics may recur, whether as a result of nature or of bioterrorism.

Factors Associated with Nursing Home Placement of All Patients Admitted for Inpatient Rehabilitation in Singapore Community Hospitals from 1996 to 2005: A Disease Stratified Analysis

Objectives To (1) identify social and rehabilitation predictors of nursing home placement, (2) investigate the association between effectiveness and efficiency in rehabilitation and nursing home placement of patients admitted for inpatient rehabilitation from 1996 to 2005 by disease in Singapore. Design National data were retrospectively extracted from medical records of community hospital. Data Sources There were 12,506 first admissions for rehabilitation in four community hospitals. Of which, 8,594 (90.3%) patients were discharged home and 924 (9.7%) patients were discharged to a nursing home. Other discharge destinations such as sheltered home (n = 37), other community hospital (n = 31), death in community hospital (n = 12), acute hospital (n = 1,182) and discharge against doctor’s advice (n = 24) were excluded. Outcome Measure Nursing home placement. Results Those who were discharged to nursing home had 33% lower median rehabilitation effectiveness and 29% lower median rehabilitation efficiency compared to those who were discharged to nursing homes. Patients discharged to nursing homes were significantly older (mean age: 77 vs. 73 years), had lower mean Bathel Index scores (40 vs. 48), a longer median length of stay (40 vs. 33 days) and a longer time to rehabilitation (19 vs. 15 days), had a higher proportion without a caregiver (28 vs. 7%), being single (21 vs. 7%) and had dementia (23 vs. 10%). Patients admitted for lower limb amputation or falls had an increased odds of being discharged to a nursing home by 175% (p<0.001) and 65% (p = 0.043) respectively compared to stroke patients. Conclusions In our study, the odds of nursing home placement was found to be increased in Chinese, males, single or widowed or separated/divorced, patients in high subsidy wards for hospital care, patients with dementia, without caregivers, lower functional scores at admission, lower rehabilitation effectiveness or efficiency at discharge and primary diagnosis groups such as fractures, lower limb amputation and falls in comparison to strokes.

Functional Outcomes after Inpatient Rehabilitation in a Prospective Stroke Cohort

Aim: Rehabilitation is proven to improve function following a stroke. The functional outcomes of stroke patients and benefits from rehabilitation are highly variable. We aim to describe functional outcomes and gains following inpatient rehabilitation post-stroke and identify factors associated with improved outcomes. Methods: In this five-years prospective study, data for 1332 consecutive stroke patients admitted to the Singapore General Hospital inpatient rehabilitation unit were charted into a custom-designed rehabilitation database. The primary outcome measure was the Functional Independence Measure (AFIM) and discharge (DFIM). The functional gain was defined as the DFIM-AFIM. Results: The mean age was 64.1±12.5 years, 58.9% were male patients and 78.9% consisted of ischaemic (versus haemorrhagic) strokes. The average rehabilitation length of stay (RLOS) was 18.7±13.9 days and the majority (87.7%) were discharged home. The most common risk factor was hypertension (78.4%) and urinary tract infection (21.2%) was the commonest post-stroke complication. The mean AFIM and DFIM scores were 67.9±23.0 and 83.2±23.5 respectively with a mean functional gain of 15.4±12.3 FIM points. Younger, male, and haemorrhagic stroke patients had better functional outcomes. Multiple regression analysis results revealed that higher DFIM score was associated with higher admission motor and cognitive FIM scores, younger age, male gender, employment at admission, single patients, presence of a caregiver, haemorrhagic stroke, right-sided motor impairments, absence of urinary tract infection or depression, acupunction treatment, and a longer RLOS. The regression model on functional gain was associated with similar independent predictors on DFIM scores except that a higher AFIM was associated with lower functional gains. Conclusion: In this large cohort study, stroke patients make significant functional gains and should be offered rehabilitation to improve outcomes. A comprehensive set of multiple interacting demographic, clinical, cultural, and social factors significanctly impact on stroke functional outcomes after inpatient rehabilitation. The identification of these factors allows optimising rehabilitation for individual patients, and is important for discharge and resource planning.

How Do Recurrent and First-Ever Strokes Differ in Rehabilitation Outcomes?

ObjectiveTo describe clinical characteristics and functional outcomes in recurrent stroke, identify factors associated with improved outcomes, and to compare these outcomes with first-ever stroke patients. DesignFive-year prospective cohort study of 1277 consecutive stroke patients admitted to inpatient rehabilitation, with 16.6% recurrent stroke. Primary functional outcome measure was the Functional Independence Measure. FIM gain quantified the difference between admission and discharge FIM scores. FIM effectiveness measured the percentage recovery. ResultsIn recurrent stroke patients, mean AdmissionFIM and DischargeFIM scores were 62.5 and 74.2, respectively, with a mean FIM gain of 11.7 and FIM effectiveness of 20.4%. Comparing to first-ever stroke, recurrent stroke patients were older, had higher unemployment rates, higher proportion of ischemic stroke types, and higher prevalence of hypertension, diabetes, ischemic heart disease, and depression. In multivariate analysis of the entire cohort, recurrent stroke predicted lower FIM gains and effectiveness. When the recurrent stroke group was further sub-analyzed, better FIM gain was associated with higher cognitive AdmissionFIM scores and presence of a caregiver, whereas better FIM effectiveness was correlated with higher motor AdmissionFIM scores. ConclusionsRecurrent stroke patients made less functional gains compared to first-ever stroke patients. However, improvements were still significant and these patients should be offered comprehensive inpatient rehabilitation to optimize outcomes. To Claim CME Credits:Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME Objectives:Upon completion of this article, the learner will be able to: (1) Describe unique demographics, and characteristics of recurrent stroke patients admitted for inpatient rehabilitation; (2) Differentiate functional outcomes between first-ever and recurrent stroke patients; and (3) Utilize factors associated with functional improvements in recurrent strokes in treatment planning. Level:Advanced Accreditation:The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The Association of Academic Physiatrists designates this activity for a maximum of 1.5 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Can caregivers report their care recipients’ post-stroke hospitalizations and outpatient visits accurately? Findings of an Asian prospective stroke cohort

BackgroundHealth services research aimed at understanding service use and improving resource allocation often relies on collecting subjectively reported or proxy-reported healthcare service utilization (HSU) data. It is important to know the discrepancies in such self or proxy reports, as they have significant financial and policy implications. In high-dependency populations, such as stroke survivors, with varying levels of cognitive impairment and dysphasia, caregivers are often potential sources of stroke survivors’ HSU information. Most of the work conducted on agreement analysis to date has focused on validating different sources of self-reported data, with few studies exploring the validity of caregiver-reported data. Addressing this gap, our study aimed to quantify the agreement across the caregiver-reported and national claims-based HSU of stroke patients.MethodsA prospective study comprising multi-ethnic stroke patient and caregiver dyads (N = 485) in Singapore was the basis of the current analysis, which used linked national claims records. Caregiver-reported health services data were collected via face-to-face and telephone interviews, and similar health services data were extracted from the national claims records. The main outcome variable was the modified intraclass correlation coefficient (ICC), which provided the level of agreement across both data sources. We further identified the amount of over- or under-reporting by caregivers across different service types.ResultsWe observed variations in agreement for different health services, with agreement across caregiver reports and national claims records being the highest for outpatient visits (specialist and primary care), followed by hospitalizations and emergency department visits. Interestingly, caregivers over-reported hospitalizations by approximately 49% and under-reported specialist and primary care visits by approximately 20 to 30%.ConclusionsThe accuracy of the caregiver-reported HSU of stroke patients varies across different service types. Relatively more objective data sources, such as national claims records, should be considered as a first choice for quantifying health care usage before considering caregiver-reported usage. Caregiver-reported outpatient service use was relatively more accurate than inpatient service use over shorter recall periods. Therefore, in situations where objective data sources are limited, caregiver-reported outpatient information can be considered for low volumes of healthcare consumption, using an appropriate correction to account for potential under-reporting.