Perspectives on the design and performance of upper-limb wearable stimulation devices for stroke survivors with hemiplegia and spasticity

BackgroundVibrotactile stimulation may improve limb function after stroke; however, current studies are limited by the stationary and clinic-based apparatus used to apply this stimulation. A wearable device could provide vibrotactile stimulation in a mobile form factor, enabling further study of this technique. ObjectiveThe aim of this work is twofold: (1) Design and validate a wearable device for stroke survivors that provides vibrotactile stimulation to the upper limb, and (2) Understand features that influence stroke survivors interaction with an upper-limb wearable device. MethodsA vibrotactile glove was designed to apply stimulation to the stroke-affected hand. This device, the vibrotactile stimulation (VTS) Glove, features small electronics, provides hours of stimulation, and has the appearance of a fingerless fitness glove. We performed two studies. In Study 1, sixteen stroke survivors were given the glove and asked to wear it for three hours daily for eight weeks. Usage time, indicating adherence, was calculated by onboard sensors. The device was evaluated using a log of damages and feedback from participants. Self-reported behaviors during glove use were also collected. In Study 2, eight stroke survivors evaluated new device prototypes in a three-round iterative design study. Interviews were used to collect participant feedback as they donned and doffed the prototypes. Task completion time and correctness were measured. Thematic content analysis was used to define actionable design revisions between each round of evaluation and identify key perspectives on design principles. ResultsThe VTS Glove is lightweight, wireless, and durable. Based on Study 1, adherence appears feasible. Each participant recorded over 140 hours wearing the VTS Glove. Participants reported wearing the glove during activities such as church, social events, dining out, and using the computer. However, 69% of participants struggled to extend or insert their fingers to don the device. Our analysis in Study 2 identified six other relevant perspectives from survivors regarding the wearable devices: hand supination is difficult, grip varies without awareness, devices may lead to sweat, separate finger attachments require dexterity, social comfort is perceived as unimportant, and the affected hand is infrequently used. New device designs with revised features (VTS Phalanx, VTS Armband, and VTS Palm) could be donned in an average time of 48 seconds (vs. 5.05 minutes to don the VTS Glove).