Exoskeleton-assisted upper limb rehabilitation after stroke: a randomized controlled trial.

OBJECTIVES: The upper-limb exoskeleton training program which is repetetive and task-specific therapy can improve motor functions in patients with stroke. To compare the effect of an upper-limb exoskeleton training program with Bobath concept on upper limb motor functions in individuals with chronic stroke. METHODS: Participants were randomly assigned to exoskeleton group (EG, n = 12) or to Bobath group (BG, n = 12). Interventions were matched in terms of session duration and total number of sessions and performed 2 times per week for 6-weeks. Primary outcome was Fugl-Meyer-Upper Extremity (FMA-UE). Secondary outcomes were Modified Ashworth Scale (elbow and wrist flexor muscles), Motor Activity Log-30 which is consist of two parts as an amount of use (AOU) and quality of movement (QOM), and The Nottingham Extended Activities of Daily Living (NEADL) index. RESULTS: After 12-sessions of training, the mean (SD) FMA-UE score increased by 5.7 (2.9) in the EG, and 1.9 (1.5) points in the BG (p < .05). In total, 40% of participants (5/12) demonstrated a clinically meaningful improvement (≥5.25 points) in the FM-UE, while none of the participants reached MCID score in the bobath group. Changes in the AOU, QOM, and NEADL were significantly larger in the EG compared to BG (p < .05). 7/12 (58.33%) of participants for AOU and 5/12 (42%) of participants for QOM in the EG showed that clinically meaningful change. 5/12 of participants (42%) in the EG demonstrated ≥4.9-point increase in NEADL score. DISCUSSION: High-intensity repetitive arm and hand exercises with an exoskeleton device was safe and feasible. Exoskeleton-assisted training demonstrated significant benefits in improving upper limb functions and quality of life in individuals after stroke.

Evaluation of Unicortical Locking Screw Placement for Torsional Loads in Distal Radius Fractures: A Biomechanical Study in Cadavers.

Background We aimed to compare bio-mechanical outcomes of short-length 75%-length uni-cortical screw (SL75UCS) and full-length 100%-length screws (FL100S) under axial compression (AXC) and torsional compression (TRC) in cadaveric distal radius volar plate model. Methodology A total of 20 wrists from 10 fresh frozen cadavers were included. A 2.5 mm titanium alloy distal radius anatomical plate was placed to the distal radii in full anatomical position, just proximal to the watershed line. Three bi-cortical screws to the shaft of the radius, followed by uni-cortical drilling for distal screwing were placed. Measurement by pulling the drill once it reached the opposite cortex was applied. We selected the screw lengths such that they corresponded to the SL75UCS. In the same configuration for each of the cadavers, we delivered six screws from distal radius holes of the anatomical plate. An oscillating handsaw was used to create an extra-articular distal radius fracture model (AO 23-A3.2). We created a dorsal AP model by performing a 1-cm wedge osteotomy from the dorsal aspect. Complete separation of the volar cortex was achieved. Potting was performed by embedding the shaft of the prepared radius into the polyurethane medium. We placed aluminum apparatus into the distal end to ensure applying of AXC and TRC in bio-mechanistic tests. Results No statistically significant difference of stiffness between the SL75UCS and FL100S both under AXC (p=0.88) and TRC (p=0.82). SL75UCS and FL100S groups did not differ in elastic limit under AXC (p=0.71) and TRC (p=0.71). Maximal force on SL75UCS and FL100S groups were also similar under both AXC (p=0.71) and TRC (p=0.50). Conclusions Our study findings suggest that drilling the dorsal cortex may not be necessary in the management of distal radius fractures. Instead, utilizing SL75UCS could serve as a viable alternative. This approach offers potential advantages in reducing the risk of extensor tendon complications associated with drilling or screw protrusion. It is a safe method under torsional load to avoid drilling of the dorsal cortex and SL75UCS could be performed in order to prevent from extensor tendon complications secondary to drilling or screw protrusion.

Robot-Assisted Training of Arm and Hand Movement Shows Functional Improvements for Incomplete Cervical Spinal Cord Injury.

OBJECTIVE: The aim of the study was to demonstrate the feasibility, tolerability, and effectiveness of robotic-assisted arm training in incomplete chronic tetraplegia. DESIGN: Pretest/posttest/follow-up was conducted. Ten individuals with chronic cervical spinal cord injury were enrolled. Participants performed single degree-of-freedom exercise of upper limbs at an intensity of 3-hr per session for 3 times a week for 4 wks with MAHI Exo-II. Arm and hand function tests (Jebsen-Taylor Hand Function Test, Action Research Arm Test), strength of upper limb (upper limb motor score, grip, and pinch strength), and independence in daily living activities (Spinal Cord Independence Measure II) were performed at baseline, end of training, and 6 mos later. RESULTS: After 12 sessions of training, improvements in arm and hand functions were observed. Jebsen-Taylor Hand Function Test (0.14[0.04]-0.21[0.07] items/sec, P = 0.04), Action Research Arm Test (30.7[3.8]-34.3[4], P = 0.02), American Spinal Injury Association upper limb motor score (31.5[2.3]-34[2.3], P = 0.04) grip (9.7[3.8]-12[4.3] lb, P = 0.02), and pinch strength (4.5[1.1]-5.7[1.2] lb, P = 0.01) resulted in significant increases. Some gains were maintained at 6 mos. No change in Spinal Cord Independence Measure II scores and no adverse events were observed. CONCLUSIONS: Results from this pilot study suggest that repetitive training of arm movements with MAHI Exo-II exoskeleton is safe and has potential to be an adjunct treatment modality in rehabilitation of persons with spinal cord injury with mild to moderate impaired arm functions.

Maintaining subject engagement during robotic rehabilitation with a minimal assist-as-needed (mAAN) controller.

One challenge of robotic rehabilitation interventions is devising ways to encourage and maintain high levels of subject involvement over long duration therapy sessions. Assist-as-needed controllers have been proposed which modulate robot intervention in movements based on measurements of subject involvement. This paper presents a minimal assist-as-needed controller, which modulates allowable error bounds and robot intervention based on sensorless force measurement accomplished through a nonlinear disturbance observer. While similar algorithms have been validated using healthy subjects, this paper presents a validation of the proposed mAAN control algorithm's ability to encourage user involvement with an impaired individual. User involvement is inferred from muscle activation, measured via surface electromyography (EMG). Experimental validation shows increased EMG muscle activation when using the proposed mAAN algorithm compared to non-adaptive algorithms.

Effects of Assist-As-Needed Upper Extremity Robotic Therapy after Incomplete Spinal Cord Injury: A Parallel-Group Controlled Trial.

BACKGROUND: Robotic rehabilitation of the upper limb following neurological injury has been supported through several large clinical studies for individuals with chronic stroke. The application of robotic rehabilitation to the treatment of other neurological injuries is less developed, despite indications that strategies successful for restoration of motor capability following stroke may benefit individuals with incomplete spinal cord injury (SCI) as well. Although recent studies suggest that robot-aided rehabilitation might be beneficial after incomplete SCI, it is still unclear what type of robot-aided intervention contributes to motor recovery. METHODS: We developed a novel assist-as-needed (AAN) robotic controller to adjust challenge and robotic assistance continuously during rehabilitation therapy delivered via an upper extremity exoskeleton, the MAHI Exo-II, to train independent elbow and wrist joint movements. We further enrolled seventeen patients with incomplete spinal cord injury (AIS C and D levels) in a parallel-group balanced controlled trial to test the efficacy of the AAN controller, compared to a subject-triggered (ST) controller that does not adjust assistance or challenge levels continuously during therapy. The conducted study is a stage two, development-of-concept pilot study. RESULTS: We validated the AAN controller in its capability of modulating assistance and challenge during therapy via analysis of longitudinal robotic metrics. For the selected primary outcome measure, the pre-post difference in ARAT score, no statistically significant change was measured in either group of subjects. Ancillary analysis of secondary outcome measures obtained via robotic testing indicates gradual improvement in movement quality during the therapy program in both groups, with the AAN controller affording greater increases in movement quality over the ST controller. CONCLUSION: The present study demonstrates feasibility of subject-adaptive robotic therapy after incomplete spinal cord injury, but does not demonstrate gains in arm function occurring as a result of the robot-assisted rehabilitation program, nor differential gains obtained as a result of the developed AAN controller. Further research is warranted to better quantify the recovery potential provided by AAN control strategies for robotic rehabilitation of the upper limb following incomplete SCI. ClinicalTrials.gov registration number: NCT02803255.

Idiopathic giant cell myocarditis in childhood: A case report.

Idiopathic giant cell myocarditis is a rare entity of unknown origin, which causes sudden death in more than half of the affected patients. It is rarely seen in childhood, and might result in death due to heart failure and ventricular arrhythmias. Idiopathic giant cell myocarditis is mostly diagnosed at autopsy incidentally. Here we present a rare case of childhood idiopathic giant cell myocarditis. A 10-year old boy found dead in his bed in the morning. Interview with family members revealed death the boy was in good health conditions apart from being overweight. At autopsy, external examination was completely normal. Internal examination revealed normal findings; the heart was 297g and macroscopically normal. No traces of any toxic agents detected in complete toxicological analyses. Areas characterized with granulomatous lesions, lymphocytes, histiocytes, and multinucleated giant cells were observed in myocardium at histopathological examination. No necrosis was observed in granulomatous areas. Tuberculosis was negative in the PCR assays. There were no signs indicative of fungal infection, and clinical status of the case was not compatible with the sarcoidosis. In this respect death was attributed to idiopathic giant cell myocarditis.

Current Trends in Robot-Assisted Upper-Limb Stroke Rehabilitation: Promoting Patient Engagement in Therapy.

Stroke is one of the leading causes of long-term disability today; therefore, many research efforts are focused on designing maximally effective and efficient treatment methods. In particular, robotic stroke rehabilitation has received significant attention for upper-limb therapy due to its ability to provide high-intensity repetitive movement therapy with less effort than would be required for traditional methods. Recent research has focused on increasing patient engagement in therapy, which has been shown to be important for inducing neural plasticity to facilitate recovery. Robotic therapy devices enable unique methods for promoting patient engagement by providing assistance only as needed and by detecting patient movement intent to drive to the device. Use of these methods has demonstrated improvements in functional outcomes, but careful comparisons between methods remain to be done. Future work should include controlled clinical trials and comparisons of effectiveness of different methods for patients with different abilities and needs in order to inform future development of patient-specific therapeutic protocols.

Adaptive control of a serial-in-parallel robotic rehabilitation device.

Robotic rehabilitation is an effective platform for sensorimotor training after neurological injuries. In this paper, an adaptive controller is developed and implemented for the RiceWrist, a serial-in-parallel robot mechanism for upper extremity robotic rehabilitation. The model-based adaptive controller implementation requires a closed form dynamic model, valid for a restricted domain of generalized coordinates. We have used an existing method to define this domain and verify that the domain is widely within the range of admissible tasks required for the considered application (movements-based wrist and forearm rehabilitation). Simulation and experimental results that compare the performance of the adaptive controller to a proportional-derivative controller show that the trajectory tracking performance of the adaptive controller is better compared to the performance of a PD controller using the same values of feed-back gains. Further, comparable absolute error performance is obtained with the adaptive controller for feedback gains nearly one third that required for the PD controller. With the lower gains used in the adaptive controller, good tracking performance is achieved with a more compliant controller that will allow the subject to indicate their ability to independently initiate and maintain movement during a rehabilitation session.

System characterization of RiceWrist-S: a forearm-wrist exoskeleton for upper extremity rehabilitation.

Rehabilitation of the distal joints of the upper extremities is crucial to restore the ability to perform activities of daily living to patients with neurological lesions resulting from stroke or spinal cord injury. Robotic rehabilitation has been identified as a promising new solution, however, much of the existing technology in this field is focused on the more proximal joints of the upper arm. A recently presented device, the RiceWrist-S, focuses on the rehabilitation of the forearm and wrist, and has undergone a few important design changes. This paper first addresses the design improvements achieved in the recent design iteration, and then presents the system characterization of the new device. We show that the RiceWrist-S has capabilities beyond other existing devices, and exhibits favorable system characteristics as a rehabilitation device, in particular torque output, range of motion, closed loop position performance, and high spatial resolution.

Robotic training and clinical assessment of upper extremity movements after spinal cord injury: a single case report.

CASE REPORT: A 28-year-old woman, with incomplete spinal cord injury at the C2 level, classified as American Spinal Injury Impairment Scale C (AIS), participated in a robotic rehabilitation program 29 months after injury. Robotic training was provided to both upper extremities using the MAHI Exo-II, an exoskeleton device designed for rehabilitation of the upper limb, for 12 × 3-h sessions over 4 weeks. Training involved elbow flexion/extension, forearm supination/pronation, wrist flexion/extension, and radial/ulnar deviation. RESULTS: Outcome measures were Action Research Arm Test, Jebsen-Taylor Hand Function Test, and AIS-upper extremity motor score. Safety measures included fatigue, pain and discomfort level using a 5-point rating scale. Following training, improvements were observed in the left arm and hand function, whereas the right arm and hand function showed no improvement in any of the functional outcome measures. No excessive pain, discomfort or fatigue was reported. CONCLUSION: Data from one subject demonstrate valuable information on the feasibility, safety and effectiveness of robotic-assisted training of upper-extremity motor functions after incomplete spinal cord injury.

Mechanical design of a distal arm exoskeleton for stroke and spinal cord injury rehabilitation.

Robotic rehabilitation has gained significant traction in recent years, due to the clinical demonstration of its efficacy in restoring function for upper extremity movements and locomotor skills, demonstrated primarily in stroke populations. In this paper, we present the design of MAHI Exo II, a robotic exoskeleton for the rehabilitation of upper extremity after stroke, spinal cord injury, or other brain injuries. The five degree-of-freedom robot enables elbow flexion-extension, forearm pronation-supination, wrist flexion-extension, and radial-ulnar deviation. The device offers several significant design improvements compared to its predecessor, MAHI Exo I. Specifically, issues with backlash and singularities in the wrist mechanism have been resolved, torque output has been increased in the forearm and elbow joints, a passive degree of freedom has been added to allow shoulder abduction thereby improving alignment especially for users who are wheelchair-bound, and the hardware now enables simplified and fast swapping of treatment side. These modifications are discussed in the paper, and results for the range of motion and maximum torque output capabilities of the new design and its predecessor are presented. The efficacy of the MAHI Exo II will soon be validated in a series of clinical evaluations with both stroke and spinal cord injury patients.