Search

Background After standard care, 55%-75% of patients after stroke show a persistent paresis of the upper limb (UL). Assistive devices are developed to increase the patients’ level of independence in daily life. Objectives To investigate the potential of Functional Electrical Stimulation (FES) to assist object manipulation in activities of daily life. Design Seventeen patients after stroke were tested and analyzed in a randomized cross-over design. Methods Functional grasping was assessed by means of the Action Research Arm Test (ARAT) and the modified Box and Block Test (mBBT), in one session with and another without FES assistance. The order of sessions was randomized. Patients’ motivation was assessed after each session. Task performance and motivation were compared between conditions using the Wilcoxon test and subgroup analyses were performed for impairment severity by distribution-based mixed-factor analyses. Results When analyzing the total ARAT, FES did not effectively assist the overall performance ( P = .142), but did assist the performance of objects of the Grasp category ( P = .020). Impairment severity showed an interaction with the orthotic effect ( P = .012), as severely impaired patients profited from FES assistance and mild-moderately impaired did not. When focusing on the more functional items of the ARAT (i.e., excluding scores from thumb-middle and thumb-ring finger combinations), there was a significant orthotic effect of FES on task performance ( P = .023). Further, there was an orthotic effect for the number of transported blocks in the mBBT ( P = .033), exclusively prominent in the group of severely impaired patients. Functional Electrical Stimulation did not increase the patients’ motivation ( P = .959), which was high after both conditions. Conclusion Functional Electrical Stimulation has the potential to support object manipulation, but is dependent on impairment severity and object type. To observe a consistent orthotic effect, features of the stimulator should be further developed to generate appropriate grasps and forces across subjects and objects. Trial Registration The trial was registered with the German Clinical Trials Register (DRKS00025889).

IntroductionVirtual Reality/serious games (SG) and functional electrical stimulation (FES) therapies are used in upper limb stroke rehabilitation. A combination of both approaches seems to be beneficial for therapy success. The feasibility of a combination of SG and contralaterally EMG-triggered FES (SG+FES) was investigated as well as the characteristics of responders to such a therapy.Materials and methodsIn a randomized crossover trial, patients performed two gaming conditions: SG alone and SG+FES. Feasibility of the therapy system was assessed using the Intrinsic Motivation Inventory (IMI), the Nasa Task Load Index, and the System Usability Scale (SUS). Gaming parameters, fatigue level and a technical documentation was implemented for further information.ResultsIn total, 18 patients after stroke (62.1 ± 14.1 years) with a unilateral paresis of the upper limb (MRC ≤4) were analyzed in this study. Both conditions were perceived as feasible. Comparing the IMI scores between conditions, perceived competence was significantly increased (z = −2.88, p = 0.004) and pressure/tension during training (z = −2.13, p = 0.034) was decreased during SG+FES. Furthermore, the task load was rated significantly lower for the SG+FES condition (z = −3.14, p = 0.002), especially the physical demand (z = −3.08, p = 0.002), while the performance was rated better (z = −2.59, p = 0.010). Responses to the SUS and the perceived level of fatigue did not differ between conditions (SUS: z = −0.79, p = 0.431; fatigue: z = 1.57, p = 0.115). For patients with mild to moderate impairments (MRC 3–4) the combined therapy provided no or little gaming benefit. The additional use of contralaterally controlled FES (ccFES), however, enabled severely impaired patients (MRC 0–1) to play the SG.DiscussionThe combination of SG with ccFES is feasible and well-accepted among patients after stroke. It seems that the additional use of ccFES may be more beneficial for severely impaired patients as it enables the execution of the serious game. These findings provide valuable implications for the development of rehabilitation systems by combining different therapeutic interventions to increase patients' benefit and proposes system modifications for home use.Clinical trial registrationhttps://drks.de/search/en, DRKS00025761.

Abstract Background Augmented Reality (AR)-based interventions are applied in neurorehabilitation with increasing frequency. Depth perception is required for the intended interaction within AR environments. Until now, however, it is unclear whether patients after stroke with impaired visuospatial perception (VSP) are able to perceive depth in the AR environment. Methods Different aspects of VSP (stereovision and spatial localization/visuoconstruction) were assessed in 20 patients after stroke (mean age: 64 ± 14 years) and 20 healthy subjects (HS, mean age: 28 ± 8 years) using clinical tests. The group of HS was recruited to assess the validity of the developed AR tasks in testing stereovision. To measure perception of holographic objects, three distance judgment tasks and one three-dimensionality task were designed. The effect of impaired stereovision on performance in each AR task was analyzed. AR task performance was modeled by aspects of VSP using separate regression analyses for HS and for patients. Results In HS, stereovision had a significant effect on the performance in all AR distance judgment tasks (p = 0.021, p = 0.002, p = 0.046) and in the three-dimensionality task (p = 0.003). Individual quality of stereovision significantly predicted the accuracy in each distance judgment task and was highly related to the ability to perceive holograms as three-dimensional (p = 0.001). In stroke-survivors, impaired stereovision had a specific deterioration effect on only one distance judgment task (p = 0.042), whereas the three-dimensionality task was unaffected (p = 0.317). Regression analyses confirmed a lacking impact of patients’ quality of stereovision on AR task performance, while spatial localization/visuoconstruction significantly prognosticated the accuracy in distance estimation of geometric objects in two AR tasks. Conclusion Impairments in VSP reduce the ability to estimate distance and to perceive three-dimensionality in an AR environment. While stereovision is key for task performance in HS, spatial localization/visuoconstruction is predominant in patients. Since impairments in VSP are present after stroke, these findings might be crucial when AR is applied for neurorehabilitative treatment. In order to maximize the therapy outcome, the design of AR games should be adapted to patients’ impaired VSP. Trial registration: The trial was not registered, as it was an observational study.