Virtual Hand Illusion Induced by Visuomotor Correlations

Background: Our body schema gives the subjective impression of being highly stable. However, a number of easily-evoked illusions illustrate its remarkable malleability. In the rubber-hand illusion, illusory ownership of a rubber-hand is evoked by synchronous visual and tactile stimulation on a visible rubber arm and on the hidden real arm. Ownership is concurrent with a proprioceptive illusion of displacement of the arm position towards the fake arm. We have previously shown that this illusion of ownership plus the proprioceptive displacement also occurs towards a virtual 3D projection of an arm when the appropriate synchronous visuotactile stimulation is provided. Our objective here was to explore whether these illusions (ownership and proprioceptive displacement) can be induced by only synchronous visuomotor stimulation, in the absence of tactile stimulation.Methodology/Principal Findings: To achieve this we used a data-glove that uses sensors transmitting the positions of fingers to a virtually projected hand in the synchronous but not in the asynchronous condition. The illusion of ownership was measured by means of questionnaires. Questions related to ownership gave significantly larger values for the synchronous than for the asynchronous condition. Proprioceptive displacement provided an objective measure of the illusion and had a median value of 3.5 cm difference between the synchronous and asynchronous conditions. In addition, the correlation between the feeling of ownership of the virtual arm and the size of the drift was significant.Conclusions/Significance: We conclude that synchrony between visual and proprioceptive information along with motor activity is able to induce an illusion of ownership over a virtual arm. This has implications regarding the brain mechanisms underlying body ownership as well as the use of virtual bodies in therapies and rehabilitation

Flora and Fauna in East Asian Art

Flora and Fauna in East Asian Art is the fourth annual exhibition curated by students enrolled in the Art History Methods course. This exhibition highlights the academic achievements of six student curators: Samantha Frisoli ’18, Daniella Snyder ’18, Gabriella Bucci ’19, Melissa Casale ’19, Keira Koch ’19, and Paige Deschapelles ’20. The selection of artworks in this exhibition considers how East Asian artists portrayed similar subjects of flora and fauna in different media including painting, prints, embroidery, jade, and porcelain. This exhibition intends to reveal the hidden meanings behind various representations of flora and fauna in East Asian art by examining the iconography, cultural context, aesthetic and function of each object.https://cupola.gettysburg.edu/artcatalogs/1025/thumbnail.jp

Introducing wearable haptics for rendering velocity feedback in VR serious games for neuro-rehabilitation of children

Rehabilitation in virtual reality offers advantages in terms of flexibility and parametrization of exercises, repeatability, and continuous data recording and analysis of the progress of the patient, also promoting high engagement and cognitive challenges. Still, most of the proposed virtual settings provide a high quality, immersive visual and audio feedback, without involving the sense of touch. In this paper, we show the design, implementation, and first evaluation of a gaming scenario for upper limb rehabilitation of children with cerebral palsy. In particular, we took care to introduce haptic feedback as a useful source of sensory information for the proposed task, considering—at the same time—the strict constraints for haptic wearable devices to comply with patient’s comfort, residual motor abilities, and with the embedded tracking features of the latest VR technologies. To show the potential of haptics in a rehabilitation setup, the proposed device and rendering method have been used to improve the velocity control of upper limb movements during the VR exercise, given its importance as a motor recovery metric. Eight healthy participants were enrolled, and results showed that haptic feedback can lead to lower speed tracking errors and higher movement smoothness, making the proposed setup suitable to be used in a rehabilitation context as a way to promote movement fluidity during exercises

A randomized clinical control study on the efficacy of three-dimensional upper limb robotic exoskeleton training in chronic stroke

Background : Although robotics assisted rehabilitation has proven to be effective in stroke rehabilitation, a limited functional improvements in Activities of Daily Life has been also observed after the administration of robotic training. To this aim in this study we compare the efficacy in terms of both clinical and functional outcomes of a robotic training performed with a multi-joint functional exoskeleton in goal-oriented exercises compared to a conventional physical therapy program, equally matched in terms of intensity and time. As a secondary goal of the study, it was assessed the capability of kinesiologic measurements—extracted by the exoskeleton robotic system—of predicting the rehabilitation outcomes using a set of robotic biomarkers collected at the baseline. Methods : A parallel-group randomized clinical trial was conducted within a group of 26 chronic post-stroke patients. Patients were randomly assigned to two groups receiving robotic or manual therapy. The primary outcome was the change in score on the upper extremity section of the Fugl-Meyer Assessment (FMA) scale. As secondary outcome a specifically designed bimanual functional scale, Bimanual Activity Test (BAT), was used for upper limb functional evaluation. Two robotic performance indices were extracted with the purpose of monitoring the recovery process and investigating the interrelationship between pre-treatment robotic biomarkers and post-treatment clinical improvement in the robotic group. Results : A significant clinical and functional improvements in both groups (p < 0.01) was reported. More in detail a significantly higher improvement of the robotic group was observed in the proximal portion of the FMA (p < 0.05) and in the reduction of time needed for accomplishing the tasks of the BAT (p < 0.01). The multilinear-regression analysis pointed out a significant correlation between robotic biomarkers at the baseline and change in FMA score (R2 = 0.91, p < 0.05), suggesting their potential ability of predicting clinical outcomes. Conclusion : Exoskeleton-based robotic upper limb treatment might lead to better functional outcomes, if compared to manual physical therapy. The extracted robotic performance could represent predictive indices of the recovery of the upper limb. These results are promising for their potential exploitation in implementing personalized robotic therapy. Clinical Trial Registration clinicaltrials.gov, NCT03319992 Unique Protocol ID: RH-UL-LEXOS-10. Registered 20.10.2017, https://clinicaltrials.gov/ct2/show/NCT0331999

How Many Muscles? Optimal Muscles Set Search for Optimizing Myocontrol Performance

In myo-control, for computational and setup constraints, the measurement of a high number of muscles is not always possible: the choice of the muscle set to use in a myo-control strategy depends on the desired application scope and a search for a reduced muscle set, tailored to the application, has never been performed. The identification of such set would involve finding the minimum set of muscles whose difference in terms of intention detection performance is not statistically significant when compared to the original set. Also, given the intrinsic sensitivity of muscle synergies to variations of EMG signals matrix, the reduced set should not alter synergies that come from the initial input, since they provide physiological information on motor coordination. The advantages of such reduced set, in a rehabilitation context, would be the reduction of the inputs processing time, the reduction of the setup bulk and a higher sensitivity to synergy changes after training, which can eventually lead to modifications of the ongoing therapy. In this work, the existence of a minimum muscle set, called optimal set, for an upper-limb myoelectric application, that preserves performance of motor activity prediction and the physiological meaning of synergies, has been investigated. Analyzing isometric contractions during planar reaching tasks, two types of optimal muscle sets were examined: a subject-specific one and a global one. The former relies on the subject-specific movement strategy, the latter is composed by the most recurrent muscles among subjects specific optimal sets and shared by all the subjects. Results confirmed that the muscle set can be reduced to achieve comparable hand force estimation performances. Moreover, two types of muscle synergies namely “Pose-Shared” (extracted from a single multi-arm-poses dataset) and “Pose-Related” (clustering pose-specific synergies), extracted from the global optimal muscle set, have shown a significant similarity with full-set related ones meaning a high consistency of the motor primitives. Pearson correlation coefficients assessed the similarity of each synergy. The discovering of dominant muscles by means of the optimization of both muscle set size and force estimation error may reveal a clue on the link between synergistic patterns and the force task

An interaction torque control improving human force estimation of the rehab-exos exoskeleton

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Left Atrial-Veno-Arterial Extracorporeal Membrane Oxygenation: Step-By-Step Procedure and Case Example

Veno-arterial extracorporeal membrane oxygenation is used in patients requiring biventricular support; however, its use increases the afterload. In patients with severe aortic insufficiency or severe left ventricular disfunction, it will increase left-side filling pressures, hence the need for left ventricle unloading with an additional mechanical circulatory support device. We present a case of a patient with cardiogenic shock and severe aortic insufficiency who underwent left atrial veno-arterial extracorporeal membrane oxygenation and provide a step-by-step explanation of the technique

Procedural and Mid-Term Outcomes of Coronary Protection During Transcatheter Aortic Valve Replacement in Patients at Risk of Coronary Occlusion: Insight From a Single-Centre Retrospective Analysis

BACKGROUND: Detailed procedural analysis and long-term data is limited for coronary protection (CP) during transcatheter aortic valve replacement (TAVR) for patients with high anatomical risk for coronary occlusion (CO). We aim to assess the procedural and mid-term outcomes of CP during TAVR. METHODS: We retrospectively analyzed patients who underwent TAVR at Henry Ford Hospital, USA from January 2015 to August 2019 and identified those considered at risk of CO and underwent pre-emptive CP with or without subsequent chimney stenting (i.e. coronary stenting with intentional protrusion into the aorta). Procedural features, immediate and mid-term clinical outcomes were reviewed. RESULTS: Twenty-five out of 1166 (2.1%) patients underwent TAVR with CP, including 10 (40%) valve-in-valve procedures. Twenty-eight coronary arteries (Left: n = 11, Right: n = 11; Left + Right: n = 3) were protected. Eleven coronaries (39.3%) were electively chimney -stented due to angiographic evidence of coronary impingement (63.6%), tactile resistance while withdrawing stent (27.3%) and electrocardiogram change (9.1%). Twenty-four patients (24/25, 96%) had successful TAVR without CO. Procedure-related complications included stent-balloon entrapment (n = 1), stent entrapment (n = 1) and occlusive distal stent edge dissection (n = 1). After a mean follow-up of 19.1 months, there was 1 cardiac death but no target vessel re-intervention or myocardial infarction. CONCLUSIONS: Our study found that angiographic evidence of coronary impingement (63.6%) was the most common reason for stent deployment during TAVR with CP. The mid-term clinical outcome of CP with TAVR was favorable