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Background and Purpose— Stroke disability is a major health burden in rural China where rehabilitation services are inadequate. We aimed to determine the effectiveness of a novel nurse-led, caregiver-delivered model of stroke rehabilitation in rural China. Methods— A multicenter prospective, randomized open, blinded outcome assessed, controlled trial was conducted in 3 rural county hospitals in China: Zhangwu, Liaoning Province (Northeast); Qingtongxia, Ningxia Hui Autonomous Region (Northwest); and Dianjiang, Chongqing Municipality (Southwest). Adult patients (age 18–79 years) with residual disability (Barthel Index score ≤80/100) after a recent acute stroke were randomized to a new service model or usual care. The new intervention was multifaceted and was based on a task-shifting / training-the-trainers model, supported by a custom-designed smartphone application, where patients and caregivers received evidence-based in-hospital education and stroke rehabilitation training (focus on mobility, self-care, and toileting), delivered by trained nurses before hospital discharge, and 3 postdischarge support telephone calls. Outcome assessments were undertaken before hospital discharge and at 3 and 6 months. Primary outcome was physical functioning (Barthel Index scores) at 6 months, assessed by research staff blind to treatment allocation, adjusted for baseline covariates in an intention-to-treat analysis. Secondary outcomes included measures of mobility, health-related quality of life, mood, and caregiver burden. The study included a process evaluation that assessed intervention fidelity. Results— From November 2014 to December 2016, 246 stroke patients were randomized to intervention (n=118) or control (n=128) groups. There was no statistically significant difference in adjusted 6-month Barthel Index scores between groups (70.1 versus 74.1, mean difference, −4.0 [95% CI, −10.0 to 2.9]), nor any differences across the other outcome measures. Process evaluation interviews revealed that the intervention was desirable and positively accepted by nurses, caregivers, and patients but was considered too complex despite efforts to simplify materials for the rural context. Key strategies identified for future studies included the use of community health workers, smartphone application enhancement, and simpler and more frequent training for nurses, caregivers, and patients. Conclusions— A novel nurse-led, digital supported, caregiver-delivered stroke rehabilitation program did not improve patient physical functioning after stroke in rural China. Further stroke rehabilitation research suitable for resource-poor settings is required, with several components being suggested through stakeholder interviews in our study. Clinical Trial Registration— URL: https://www.clinicaltrials.gov . Unique identifier: NCT02247921.

SummaryUsing wearable robots is an effective means of rehabilitation for stroke survivors, and effective recognition of human motion intentions is a key premise in controlling wearable robots. In this paper, we propose an inertial measurement unit (IMU)-based gait phase detection system. The system consists of two IMUs that are tied on the thigh and on the shank, respectively, for collecting acceleration and angular velocity. Features were extracted using a sliding window of 150 ms in length, which was then fed into a quadratic discriminant analysis (QDA) classifier for classification. We recruited five stroke survivors to test our system. They walked at their own preferred speed on the level ground. Experimental results show that our proposed system has the ability of recognizing the gait phase of stroke survivors. All recognition accuracy results are above 96.5%, and detections are about 5–15 ms in advance of time. In addition, using only one IMU can also give reliable recognition results. This paper proposes an idea about the further research on human–computer interaction for the control of wearable robots.

Quantitative research of urban geography has benefited greatly from the rapid development of big geo-data. Spatial assembly is an essential analytical step to summarize and perceive geographical environment from individual behaviours. Most research focuses on the methodology of how to utilize the big data, while the adopted spatial units for data aggregation remain areal in nature. This article conceptually proposes an idea of sensing cities from a street perspective, emphasizes the significance of street units in quantitative urban studies. Using a three-month taxi trajectory dataset and the major streets in Beijing, we explore the spatio-temporal patterns of urban mobility on streets, cluster streets into nine types based on their dynamic functions and capacities. Additionally, we discuss the differences and connections between the linear street unit and traditional areal units, investigate the possibility of uncovering urban communities using streets, and point out the complexity of streets. We conclude that street unit as a supplement to areal units, is able to effectively minify the modifiable areal unit problem (MAUP), sense urban dynamics, depict urban functions, and understand urban structures.

Rationale Stroke is the leading cause of death and disability in rural China. For stroke patients residing in resource-limited rural areas, secondary prevention and rehabilitation are largely unavailable, and where present, are far below evidence-based standards. Aim This study aims to develop and implement a simplified stroke rehabilitation program that utilizes nurses and family caregivers for service delivery, and evaluate its feasibility and effectiveness in rural China. Methods and design This 2-year randomized controlled trial is being conducted in 2–3 county hospitals located in northwest, northeast, and southwest China. Eligible and consenting stroke inpatients (200 in total) have been recruited and randomized into either a control or intervention group. Nurses in the county hospital are trained by rehabilitation specialists and in turn train the family caregivers in the intervention group. They also provide telephone follow-up care three times post discharge. The recruitment, baseline, intervention, follow-up care, and evaluation are guided by the RECOVER mobile phone app specifically designed for this study. Study outcome The primary outcome is patients’ Barthel Index (activities of daily living: mobility, self-care, and toileting) at 6 months. Process and economic evaluation will also be conducted. Discussion The results of our study will generate initial high-quality evidence to improve stroke care in resource-scarce settings. If proven effective, this innovative care delivery model has the potential to improve the health and function of stroke patients, relieve caregiver burden, guide policy-making, and advance translational research in the field of stroke care.

Robotic platform based ankle-foot rehabilitation systems have been proved effective in treating joint spasticity and/or contracture of stroke survivors. However, simple force or velocity limiters are not adequate, since they cannot explicitly guarantee slow and overdamped motions without overshoot. In this paper, we propose a proxy-based sliding mode control (PSMC) based approach, to avoid unsafe behaviors of a robotic ankle-foot rehabilitation system. The proposed method has three advantages: 1) without deteriorating tracking performance during normal operation, it guarantees overdamped, slow and safe recoveries after abnormal events; 2) it provides a simple and accurate way to confine the output torque exerted on the subject's ankle; 3) though effective, the control law avoids the necessity to identify the specific system model or build state observer, which is usually difficult for human-robot interaction system. A 71-year-old stroke patient and ten able-bodied subjects were recruited for the experiments. Preliminary studies comparing PSMC and PID are performed on trajectory tracking, controlled torque output, slow and safe response under disturbance. Additionally, by fulfilling the rehabilitation method and obtaining biomechanical indicators, the proposed controller is proved to be feasible for the system.

Stroke patients with hemiparesis often exhibit an asymmetrical weight distribution, with the paretic leg providing less support and less weight-shift activity than the sound leg does. For upper-limb hemiparesis constraint-induced movement therapy (CIMT), where the sound limb is constrained and the patient is forced to use the paretic limb, has proven to be one of the most effective rehabilitation methods. However, this method has not been successfully modified for balance rehabilitation, since hard constraints on the lower limb are difficult to impose and can increase the risk of patient injuries. Here we introduce a novel approach that encourages stroke survivors to use the paretic leg for weight-shifting tasks during balance control training in a virtual reality setting. We recorded motion signals from each leg in real time and streamed modified versions of these signals to the Nintendo Wii Fit gaming system. By independently manipulating the influence of each leg during game play, we successfully forced the stroke survivors to increase the use of the paretic leg. Our preliminary clinical trial, including three patients with hemiparesis in the chronic phase, found that one-week of training improved patients’ ability to maneuver their center of pressure (COP) during a tracking task. More encouragingly, patient’s weight distributions became more symmetrical. These initial results suggest that manipulating control gains during VR rehabilitation may allow the principles of CIMT to be applied during balance training in stroke survivors.

The wide use of high voltage direct current (HVDC) equipments, such as convert transformer, DC bushing, DC cables, makes the research of oil-paper material insulation extraordinarily important. The space charge effect is the key insulation problem of HVDC equipments. This paper studied the space charge characteristics of oil-paper insulation materials by Pulsed Electro-Acoustic (PEA) method. In this paper, we studied and discussed the relationship between space charge and breakdown in oil-paper. The results show that the space charge comes from ionization at lower field intensity. When the stress is getting higher, injection of homo carriers occurs first at cathode and later at anode. The space charge inside oil-paper sample results in an electrical field distortion up to 40%. The conductivity of oil-paper insulation material is much larger than that of polyethylene, so the space charge dissipates fast when depolarized. The fast dissipation of space charge will play a key role of oil-paper insulating performance in condition of polarity reversal under HVDC. When the applied negative electrical field rose to between 50 kV/mm and 57 kV/mm, the oil-paper material got breakdown in a short time. During this process, an obvious movement of space charge was observed.

The safety is an important issue in robot-assisted rehabilitation systems. In this paper, we present a therapist-joined hybrid control method to improve the safety of a robotic ankle-foot system for post stroke rehabilitation, combining therapist-joined zero torque control and proxy-based sliding mode control in the continuous passive motion based rehabilitation. The zero torque control is applied when measuring the range of motion of the subject to obtain its extreme joint angle and largest resistance torque. According to these data, a subject-suited position controller of proxy-based sliding mode control can be specified to implement passive stretching, with desired trajectory designed and torque output limited for the subject individually. Experiments were performed to demonstrate the feasibility of the proposed method on improving safety.

In this paper, a needle–plane electrode system and polypropylene (PP) films were used to study the DC corona charging of polymers. It was found that the charges injected into the PP films sometimes show different polarity to the applied DC voltage, called polarity reversal charging, which may results in invalidation charging. The pulsed electro-acoustic (PEA) space charge measurement showed that charges of different polarities have been injected into the PP films’ bulk, simultaneously. From these results, a mechanism of two charging processes of high-field injection and return-stroke injection has been introduced here. We presumed that the return-stroke injection can be boosted with the increase of corona voltages and thus reduces the net charge as well as even change the polarity of charges injected.

Ankle joint with spasticity and/or contracture can severely affect mobility and independence of stroke survivors. Due to that, the Achilles tendon(AT) is affected. In this paper, we aim to study changes of AT properties via proprioceptive neuromuscular facilitation (PNF) treatment. A robotic ankle-foot rehabilitation system has been proposed, which consists of a robotic ankle-foot platform and a graphic user interface. In this pilot study, two post-stroke patients participated and carried out a 12-week PNF treatment with the robotic system. The treatment is evaluated quantitatively in AT properties. The evaluation shows that after the PNF treatment, the average decrease of AT length is 4.1 mm (6.5%) and the recovery ratio is 30.4%, while the thickness has no change. The results indicate that the PNF based robotic rehabilitation for ankle joints with spasticity and/or contracture is effective to improve the ankle spasticity/contracture.