Abstract
BackgroundArmeo®Spring exoskeleton is widely used for upper extremity rehabilitation; however, weight compensation provided by the device appears insufficiently characterized to fully utilize it in clinical and research settings.MethodsWeight compensation was quantified by measuring static force in the sagittal plane with a load cell attached to the elbow joint of Armeo®Spring. All upper spring settings were examined in 5° increments at the minimum, maximum, and two intermediate upper and lower module length settings, while keeping the lower spring at minimum. The same measurements were made for minimum upper spring setting and maximum lower spring setting at minimum and maximum module lengths. Weight compensation was plotted against upper module angles, and slope was analyzed for each condition.ResultsThe Armeo®Spring design prompted defining the slack angle and exoskeleton balance angle, which, depending on spring and length settings, divide the operating range into different unloading and loading regions. Higher spring tensions and shorter module lengths provided greater unloading (≤6.32 kg of support). Weight compensation slope decreased faster with shorter length settings (minimum length = −0.082 ± 0.002 kg/°; maximum length = −0.046 ± 0.001 kg/°) independent of spring settings.ConclusionsUnderstanding the impact of different settings on the Armeo®Spring weight compensation should help define best clinical practice and improve fidelity of research.
Highlights
Armeo®Spring exoskeleton is widely used for upper extremity rehabilitation; weight compensation provided by the device appears insufficiently characterized to fully utilize it in clinical and research settings
A 10° change in elevation angle results in 0.82 kg of unloading or loading using module length Upper module length 1 (U1L1) but only 0.46 kg using Upper module length 10 (U10L12). This occurs because the magnitude of weight compensation is determined by the difference in torque produced by the upward pull of the spring and the downward pull of the exoskeleton
This study confirmed that the weight compensation characteristics of the Armeo®Spring exoskeleton are primarily affected by spring tension and, to a lesser degree, module length settings
Summary
Armeo®Spring exoskeleton is widely used for upper extremity rehabilitation; weight compensation provided by the device appears insufficiently characterized to fully utilize it in clinical and research settings. Robotic technology has been increasingly used for assessing and treating upper extremity motor deficits after a neurological injury. Robotic devices can be classified as end-effectors or exoskeletons, interfacing with the distal joint only or aligned with both proximal and distal joints, respectively [3, 5]. They are generally described as providing assistance to complete a desired movement or resistance to dampen or prevent undesired movements or deviations from a predetermined path [7]. Increasing the amount of weight compensation has been shown to increase range of motion [8] and decrease muscle activation [9–11], which has been associated with decoupling flexor synergies after stroke [12]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
