Abstract— Rehabilitation robot is a robot for assisting the patient to recover from stroke or other extremity injuries. As the number of post-stroke patients is increased, it needs more rehabilitation robot to support post-stroke patients. Generally, rehabilitation robots used for lower limb rehabilitation are highly priced and not affordable to the lower income segment of the population. This is caused by the application of the current control system that needs expensive hardware system. Therefore, we design the control system by using Pulse Width Modulation (PWM) controller. This paper presents the result of our research that aim to develop lower limb rehabilitation robot control system with a low price by using a PWM controller for voltage manipulation. The system model and hardware implementation have been built to show the effectiveness of the proposed system and to find the optimal conditions.
Robotic trainings with games have shown the potential to recover stroke patients in clinical trials. In this article, the control algorithm for active exercise and the implementation of related software and hardware are developed so that the lower limb rehabilitation robot in sitting position could provide game training sessions. Moreover, the characteristics of the exoskeleton that moves together with the human’s leg is applied in order to obtain the human mechanical power at each joint for any training activity and modality. It is shown that the derived mechanical power is able to identify the performance of the human subject in active and passive cycling exercises. In the training sessions with games (“Stack Jump” and “Armor”) controlled by a single joint (hip, knee, or ankle joint), the movement frequencies are higher than those from some clinical tests reported in previous research. Therefore, the game-based training with the lower limb rehabilitation robot is promising to provide exercise with sufficient intensity for a patient to gain positive clinical outcomes. Moreover, it is found that the human mechanical power in these game sessions is able to identify the intensity of the tasks, the human performance at each joint, as well as, the attention of the subject during the training session. Therefore, the robot providing game sessions would help monitoring the progress of patient recovery and the evaluation of the performance of a patient.
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traditional EMG acquisition devices are always wired, inconvenient, and non-portable. The current wireless techniques for EMG equipment usually focus on Bluetooth, Zigbee, or FSK (Hussain et al ., 2013). The disadvantage is that the collected EMG data can only be used for local processing. As the Wi-Fi protocol has advantages of network access ability, high transmission bandwidth and low error rate over other wireless techniques, it can be used to complete the wireless transmission of EMG signals from the acquisition devices to the processing platforms. There are several commercial Wi-Fi based EMG acquisition devices, such as the BTS FREEEMG from BTS Bioengineering Corp. and the devices from Shanghai NCC Medical Co., Ltd. However, these commercial equipments are not selected by the authors because they are very expensive and this will increase the cost dramatically. The real-time performance is indeed an important issue when applying EMG devices to robot control. The self-developed device can also satisfy the real-time requirement by using Wi-Fi protocol. Considering the system compatibility when integrating it with the robot platform in our experiment, we choose to develop such a device by ourselves. The wireless EMG acquisition device designed by the researcher’s group is presented in Figure 2, in which (a) is the system architecture, and (b) is the picture of the hardware device. The central unit is a high-performance monolithic processor STM32F103RC6, and the communication unit employs a WM-MR-08 module as the 802.11b/g baseband controller. In addition, the device is also integrated within a lithium battery and a power management system. Specifically, the sampling resolution is 12bit, with a bandwidth of 20~500Hz. The system amplification gain is set to 60db, wherein the preamplifier gain is 20db and the final gain is 40db.
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Based on the software system architecture discussed in the previous sections and related algorithms, the autonomous map construction, real-time path planning and obstacle avoidance functions of the robot under unknown environment are tested in the gazebo physics simulation scenario. Figure 4 shows the constructed scenario and Figure 5 presents the autonomous mapping results. It can be seen that they are agreed very well. Through the analysis of experimental phenomena and algorithm effects, the performance of the visual navigation system and the effectiveness of the automated construction algorithm of the wheeled robot in the simulation environment are verified.
The number of patients with lower extremity dyskinesia caused by stroke, spinal injury and brain trauma has increased year by year. Lower extremity dyskinesia seriously affects patients' daily life and imposes a heavy burden on patients. In recent years, with the rapid development of robotics, many scholars have combined intelligent robot technology with rehabilitation medicine, using the characteristics of high robot motion precision, strong interaction, intelligent automatic to assist or replace the rehabilitation physician to complete the exercise treatment .
Tsinghua University, as the earliest Institute in mainland China to study lower limb rehabilitation robot, has expanded its research direction from the original horizontal foot pedal lower limb rehabilitation robot similar to bicycle principle to the exoskeleton lower limb rehabilitation robot with weight-reducing balance frame (see Figure 4). It is similar to Lokomat of Hocoma (Switzerland), and has obvious effect on patients’ gait recovery training. But its disadvantage is that in order to solve the problem that the position control algorithm lags behind the actual position, the position control is only used in the swing phase, which will cause slippage between the sole of the foot and the conveyor belt of the medical runway, and the frequent switch of the motor will lead to vibration    .
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This study was conducted to determine the effect of patello-femoral rehabilitation on lower limb mechanical changes postnatally. One hundred women complaining from postpartum mild to moderate knee pain and/or mild degree of knee inflammation and/or lower limb functional problem participated in this study. They were selected randomly from Said Galal University Hospital in Cairo. They were diagnosed by physician. The study was conducted from January 2016 to March 2017. Their ages were ranged from 20-35 years old. Their BMI was ranged from 20-35 kg/m2.They were divided into two groups equal in number, group (A) treated by nutrition program only in the form of balanced diet 1200-1400 Kcal/day while group (B) treated by the same diet (1200- 1400 Kcal/day) and participated in 90 minutes session of patellofemoral rehabilitation program and localized fat lipolysis using sonoliser device on thigh region twice weekly for 3 months. BMI was assessed by using weight and height scale, anterior knee pain was assessed by VAS, navicular drop test and thigh girth were assessed by tape measurement, Q angle was assessed by goniometer and functional activities of hip and knee joints were assessed by LEFS for both groups A and B before and after treatment. Results found that, there was no significant difference in BMI, VAS, NDT, Q angle, LEFS and thigh girth between both groups A and B before treatment. There was significant improvement in BMI, VAS, NDT, Q angle, LEFS and thigh girth in both groups A and B after treatment. There was significant difference between A and B in BMI, VAS, NDT, Q angle, LEFS and thigh girth between groups A and B after treatment (more improvement in group B).
Six men with a median age of 32 years (range 25-46) and median time since amputation of 5.7 years (range 2-17) identified from the register of wounded veterans served as participants. Of the eleven veterans with lower limb amputations approached for participation in the study, six consented to take part and completed interviews. All participants were injured by improvised explosive devices and they all had life saving surgery in a field hospital and were subsequently transferred to the receiving hospital in Denmark for further surgery and treatment. All participants included in this study used a prosthesis. The dataset consisted of six transcribed interviews and field notes from four weekly rehabilitation sessions of participant observation (four of the six
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The aim of this study was to evaluate inter- and intra-rater reliability of a recently developed measurement method assessing isometric muscle force in a driven gait orthosis (DGO). Therefore two experienced therapists tested 16 subjects without and 14 subjects with NMD on the same day to assess inter-rater reliability, and one therapist tested the subjects on two separate days to assess intra- rater reliability. Our results showed that the developed assessment tool for a DGO is a reliable tool for measuring isometric torques in subjects with and without neurologi- cal movement disorders. Therefore, it can be applied as an objective outcome measure in rehabilitation units. This novel method allows therapists to assess the muscle status of their patients walking in the DGO with a timesaving method and additionally to control and document the rehabilitation process.
In this study, a novel variable impedance control for a lower-limb rehabilitation robotic system using voltage control strategy is presented. The majority of existing control approaches are based on control torque strategy, which require the knowledge of robot dynamics as well as dynamic of patients. This requires the controller to overcome complex problems such as uncertainties and nonlinearities involved in the dynamic of the system, robot and patients. On the other hand, how impedance parameters must be selected is a serious question in control system design for rehabilitation robots. To resolve these problems this paper, presents a variable impedance control based on the voltage control strategy. In contrast to the usual current-based (torque mode) the use of motor dynamics lees to a computationally faster and more realistic voltage-base controller. The most important advantage of the proposed control strategy is that the nonlinear dynamic of rehabilitation robot is handled as an external load, hence the control law is free from robot dynamic and the impedance controller is computationally simpler, faster and more robust with negligible tracking error. Moreover, variable impedance parameters based on Interval Type-2 Fuzzy Logic (IT2Fl) is proposed to evaluate impedance parameters. The proposed control is verified by a stability analysis. To illustrate the effectiveness of the control approach, a 1-DOF lower-limb rehabilitation robot is designed. Voltage- based impedance control are simulated through a therapeutic exercise consist of Isometric and Isotonic exercises. Simulation results show that the proposed voltage- based variable impedance control is superior to voltage-based impedance control in therapeutic exercises.
efficient. The increased efficiency of using quaternion rotation as opposed to Euler rotations comes from the reduced number of variables required to describe the rotation, where in Euler angles there are three variables required for each rotation about the three axes, making nine variables in total, with quaternion rotation, there are only 4 variables describing the scalar and vector of the quaternion. Quaternions also provide smooth rotations as there is only one axis of rotation, whereas with Euler angles, there are three axes of rotation. These advantages of quaternions make them preferable for use in robotic applications over Euler angles, and were used as the basis of the orientation components of this project, with the orientation data from the motion sensor being formatted as quaternion orientation, and the robot controller requiring quaternion orientations for its robot control functions. Figure 5.3 shows the concept of quaternion rotation, with scalar S(q) = Qw describing the half angle of the rotation about the axis, and vector V(q) = (Qx, Qy, Qz) describing the axis of rotation.
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A particularly relevant problem related to the use of exoskeletons in rehabilitation or assistance is their effect on balance. Users ’ balance may be compromised when using ambulatory unilateral or bilateral exoskeletons, due to the weight of the device and its behaviour. In addition, the loss of walking functions in most patients is frequently associated with balance disorders . As a result, ambulatory exoskeletons are normally used in combination with crutches [25, 40, 70, 82]. The use of crutches may improve user ’ s self-confidence, serve as a feedback tool, and reduce the risks of falls . In clin- ical/research settings, non-ambulatory exoskeleton are usually supported with treadmill-based structures, stand- ing structures or safety harness [26, 36, 38, 42, 59, 60, 65 – 67, 71, 84, 85]. Apart from the inclusion of these safety devices, balance is a topic that has been largely overlooked in the exoskeleton literature, and should be seriously considered in the future, both from the assess- ment and control point of view.
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Similarly, other studies reported the results of angioplasty performed in patients with lower limb occlusive peripheral arterial disease and compared combined treatment (angioplasty with SEP) with angioplasty alone. Kruidenier et al. determined that SET following a percutaneous vascular intervention (PVI) was more effective and increased walking distance compared with PVI alone. These data indicate that SET is a useful adjunct to a PVI for the treatment of PAD . However another study observed that percutaneous transluminal angioplasty (PTA), the SEP and combined treatment (PTA plus SEP) were all equally effective in improving walking distance for patients with intermittent claudication due to femoral-popliteal disease. SEP was carried out three times a week for 12 weeks and patients were assessed at baseline and 1, 3, 6 and 12 months after intervention .
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The two co-primary outcome measures are the maximal ambulation speed barefoot over 10 m for the lower limb, and the Modified Frenchay Scale for the upper limb. Secondary outcome measures include total cost of care from the medical insurance point of view, physiological cost index in the 2-min walking test, quality of life (SF 36) and measures of the psychological impact of the two treatment modalities. Participants will be evaluated every 6 months (D1/M6/ M12/M18/M24) by a blinded investigator, the experimental period being between M6 and M18. Each patient will be allowed to receive any medications deemed necessary to their attending physician, including botulinum toxin injections. Discussion: This study will increase the level of knowledge on the effects of Guided Self-rehabilitation Contracts in patients with chronic stroke-induced hemiparesis.
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Nowadays, lower limb rehabilitation device is an important and the only device that can help the post stroke patient who have hemiparesis problem and unable to walk without assistance to regain their walking ability by having training at their lower limb. Therefore, lower limb rehabilitation training for the post stroke patient is needed to allow them to regain the skills and having a normal life like before the stroke.
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Kinematic analysis in stroke patients undergoing con- ventional treatment has previously revealed the range and coordination of upper limb joints [30,31], as well as dis- criminate between compensatory movement and motor recovery . It offers minute details of patient’s movement in contrary to clinical assessments which are developed on the basis of evaluating conventional rehabilitation. As a result, the scores in clinical assessments are highly coarse and ordinal [32,33] albeit accompanied with rubrics to explain the measures; thus require strong inter-rater relia- bility score to truly judge the psychometric aspects of the assessment . The fact that the gold standard of clin- ical assessment remains subjective, helps to alleviate the importance of in-depth analysis and objective measure- ments to enhance understanding of patient’s improvement by offering a finer level of granularity. However, with- out comprehensive studies in establishing relationship of a large variety of kinematic variables to aspects of eval- uation in standard clinical assessments, the acceptance of kinematic evaluation scales in practice is challeng- ing. Attempts to develop such scale has been made  although with minimal success.
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All search results were exported to bibliographic software (Citavi 4.1, Swiss Aca- demic Software GmbH). One review author (LFS) screened paper titles retrieved from the search in order to exclude obviously irrelevant references. Abstracts or full texts or both of the remaining studies were obtained and used on the inclusion criteria to assess whether they were eligible for inclusion. Disagreements were resolved by discussion between two review authors (LFS and KM). The included articles were first analysed on their use of Movement Visualisation. This was done on the basis of the information provided in the article text and available images. Thereafter, study characteristics were then extracted in a tabular format which included: motor function, sample population, sample size, immersion, and use of robotic device. Immersion was categorized accord- ingly to Kalawsky  into non-immersive (desktop monitor), semi-immersive (large screen monitor or projection systems with more than 60° wide angle display, with or without 3D shutter glasses), and fully immersive (360° wide angle display, e.g. with a Head Mounted Display). Additionally, categories of augmented reality (real world sup- plemented with virtual information) and commercial gaming system (systems that have not been designed for rehabilitation purposes) were used.
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Prosthetic feet are very important for regaining the walking ability by the persons who have lost this ability due to some injury or by some other causes. Each foot serves to provide for the needs of a slightly different user than the next. A prosthetic provides a stable weight-bearing surface, absorbs shock, replaces lost muscle function, replicates the anatomic joint, and restores cosmetic appearance (‘Lower Limb Prosthetics’). Users of prosthetic feet can be broken down into functional levels which relate to their activity level and needs for their prostheses. A Level 0 amputee does not have the ability to go through the gait cycle due to massive injuries. A prosthetic would not help someone at a Level 0. A Level 1 has the ability to ambulate, but does not have the stability to walk on sloped ground. A Level 2 amputee can travel on some varying terrain and slopes. A Level 3 can traverse ranging slopes and conditions. They have varying activity levels. The last level, a Level 4, has high mobility and will subject their prosthetic to high impact and high stress situations [6-9].
general control strategy have been implemented to increase the rate of patient recovery by assisting patients only when force-guidance is required. Common methods for applying this assist-as-needed therapy are to establish a region around the desired trajectory where the patient will receive no assistance, or to activate this assistance only if the patient has not moved for a certain period of time [51, 52, 53]. Impedance parameters were also tuned automatically using adaptive and performance-based methods during a task or between tasks to challenge patients more as they recover . Patients can be quite strong and rigid, especially in the case of the lower-limb deficit, and this has forced many robot designs to select powerful motors that are heavy and costly or opt for higher gearing that creates backdrivability issues. This lack of passive backdrivability can diminish the performance of impedance control algorithms, motivating researchers to use admittance control algorithms  and/or EMG feedback  to capture the patient’s movement intent through force feedback and provide motion accordingly. It is still unclear which methods of control are most useful in establishing therapy regimens for patients with neuromuscular deficit, and through iterative design, control, and clinical experimentation, further knowledge will be generated on how to perform rehabilitative therapy, both robotically and traditionally, for maximal patient recovery.
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Actuators are the device that provide motion for the exoskeleton and hence support the wearer’s limb motion. It takes the command from the controller and provides motion according to the requirement at a certain instant. Electrical Actuator is one of the most popular choices due to its clean and silent operation as well as lower power consumption than others . Some of the electrical actuators used by previous studies include DC Servomotor, Linear Actuator and Series Elastic Actuator.
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