Assist-As-Needed Exoskeleton for Hand Joint Rehabilitation Based on Muscle Effort Detection.

Robotic-assisted systems have gained significant traction in post-stroke therapies to support rehabilitation, since these systems can provide high-intensity and high-frequency treatment while allowing accurate motion-control over the patient's progress. In this paper, we tackle how to provide active support through a robotic-assisted exoskeleton by developing a novel closed-loop architecture that continually measures electromyographic signals (EMG), in order to adjust the assistance given by the exoskeleton. We used EMG signals acquired from four patients with post-stroke hand impairments for training machine learning models used to characterize muscle effort by classifying three muscular condition levels based on contraction strength, co-activation, and muscular activation measurements. The proposed closed-loop system takes into account the EMG muscle effort to modulate the exoskeleton velocity during the rehabilitation therapy. Experimental results indicate the maximum variation on velocity was 0.7 mm/s, while the proposed control system effectively modulated the movements of the exoskeleton based on the EMG readings, keeping a reference tracking error <5%.

Estudio clínico de no-inferioridad y de equivalencia: metodología, análisis e interpretación / Non-inferiority and equivalence clinical trials: methodology, analysis and interpretation of the results

Los estudios controlados con placebo son el método ideal para evaluar la eficacia del tratamiento médico. Debido al gran número de tratamientos de comprobada eficacia en ciertas aplicaciones, los estudios controlados con placebo son a menudo poco éticos. Los estudios de no-inferioridad y de equivalencia son apropiados para evaluar la eficacia de un tratamiento experimental versus un control activo cuando se plantea la hipótesis que el tratamiento experimental puede no ser superior a un tratamiento de comprobada eficacia, pero es clínica y estadísticamente no inferior. El diseño y el reporte de estos estudios deben de seguir las recomendaciones del grupo CONSORT. Para tal fin, es indispensable seleccionar un óptimo control activo. La eficacia del control activo debería ser documentada a través de buenos estudios históricos controlados con placebo; a partir de estos datos es indispensable determinar el margen de no-inferioridad. Los resultados del nuevo tratamiento deben ser comparados con el control activo por análisis múltiples, incluyendo el placebo putativo. El término de no-inferioridad es usado cuando se refiere a un estudio de una sola cola (diferencia en respuesta menor que delta); equivalencia cuando se refiere a estudio de dos colas (diferencia en respuesta entre -Δ y +Δ). Para documentar los planteamientos teóricos se recurre a datos de estudios publicados recientemente, relacionados con moléculas eficaces en el control de la presión arterial y en la reducción de los índices de mortalidad en enfermedades cardiovasculares.

Placebo-controlled trials are the ideal for evaluating medical treatment efficacy. Given the large number of proven effective treatment in several areas, placebo-controlled trials are often unethical. The non-inferiority and equivalence trials are appropriate for evaluation of the efficacy of an experimental treatment versus an active control when it is hypothesized that the experimental treatment may not be superior to a proven effective treatment, but is clinically and statistically not inferior in effectiveness. The design and reporting of these studies must follow the CONSORT statements. An active control must be selected. Good historical placebo-controlled trials documenting the efficacy of the active control must exist. From these historical trials, a margin of non-inferiority must be determined. The results of the new treatment must be compared with active control through multiple analysis, including a putative placebo comparison. The term non-inferority is used when referring to a 1-sided trial (difference in response lower than Δ); equivalence, when referring to 2-sided trials (difference in response between-Δ and +Δ). In order to give practical data, results of published trials related to active molecules effective in the control of blood pressure and in reducing mortality in cardiovascular diseases are used.