We constructed a powered ankle–foot orthosis for human walking with a novel myoelectric controller. The orthosis included a carbon fiber and polypropylene shell, a metal hinge joint, and two artificial pneumatic muscles. Soleus electromyography (EMG) activated the artificial plantar flexor and inhibited the artificial dorsiflexor. Tibialis anterior EMG activated the artificial dorsi-flexor.We collected kinematic, kinetic, and electromyographic data for a naive healthy subject walking with the orthosis. The current design improves upon a previous prototype by being easier to don and doff and simpler to use. The novel controller allows naive wearers to quickly adapt to the orthosis without artificial muscle co-contraction. The orthosis may be helpful in studying human walking biomechanics and assisting patients during gait rehabilitation after neurological injury.

(далее…)

Категория: Научные статьи | Нет комментариев »

Actualmente algunas de las aplicaciones de los exoesqueletos de partes superiores son la rehabilitación y la amplificación de las habilidades del brazo humano. Nuestro estudio se enfoca en las aplicaciones de rehabilitación, en las cuales se busca restaurar las funciones de los miembros atrofiados. Como etapa esencial en el entendimiento de la movilidad del brazo, está el análisis cinemático, análisis hecho a partir de las mismas teorías que envuelven el estudio de actuadores robóticos industriales. Este estudio es la base para el objetivo final de una primera etapa: determinar del espacio de trabajo del brazo humano teniendo en cuenta los rangos de movilidad en las articulaciones a los cuales un exoesqueleto estaría sometido. Para este análisis se consideró un modelo de 7 GDL que describe los movimientos y las restricciones de cada una de las articulaciones del brazo (hombro, codo y muñeca) y con él se define el alcance real que tiene la muñeca a través del espacio de trabajo del sistema. Gráficas y conclusiones acompañan este documento.

(далее…)

Категория: Научные статьи | Нет комментариев »

This chapter discusses the advantages and feasibility of using compliant actuators in exoskeletons. We designed compliant actuation for use in a gait rehabilitation robot. In such a gait rehabilitation robot large forces are required to support the patient. In case of poststroke patients only the affected leg has to be supported while the movement of the unaffected leg should not be hindered. Not hindering the motions of one of the legs means that mechanical impedance of the robot should be minimal. The combination of large support forces and minimal impedances can be realised by impedance or admittance control. We chose for impedance control. The consequence of this choice is that the mass of the exoskeleton including its actuation should be minimized and sufficient high force bandwidth of the actuation is required. Compliant actuation has advantages compared to non compliant actuation in case both high forces and a high force tracking bandwidth are required. Series elastic actuation and pneumatics are well known examples of compliant actuators. Both types of compliant actuators are described with a general model of compliant actuation. They are compared in terms of this general model and also experimentally. Series elastic actuation appears to perform slightly better than pneumatic actuation and is much simpler to control. In an alternative design the motors were removed from the exoskeleton to further minimize the mass of the exoskeleton. These motors drove an elastic joint using flexible Bowden cables. The force bandwidth and the minimal impedance of this distributed series elastic joint actuation were within the requirements for a gait rehabilitation robot.

(далее…)

Категория: Научные статьи | Нет комментариев »

This document represents the final report of the study “Non invasive brain-machine interfaces” performed by the Interdepartmental Research Center “E. Piaggio” of the University of Pisa within the ARIADNA framework of activities promoted by the European Space Agency (ESA). Contents of the report are organized as follows. The first part presents a literature survey on the state of the art of brain-machine interfaces (BMI), with a particular emphasis on the non-invasive types. In order to discuss potential benefits deriving from the use even of additional interfa-ces, conceived as complementary and auxiliary for BMI, the second part reviews different types of non-invasive man-machine interfaces. Their working principles, implementations, possible applications and typical features are discussed. Such additional interfaces are considered as a useful help, especially for multi-task activities. The report then presents a selection of the most promising and feasible non- nvasive BMI concept for space applications, as well as the most interesting man-machine interface concepts capable of working as auxiliary and complementary tools. In particular, selected concepts consist of EEG- based BMI, to be eventually used in combination with interfaces based on speech recognition, EMG activation and motion capture and gesture recognition. The final part reports potential fields of space applications for such types of interfaces.

(далее…)

Категория: Научные статьи | Нет комментариев »

The focus of our research program is the restoration of limb function through a biohybrid approach. We consider the limb conceptually as a biohybrid organ con-sisting of biological tissue, endoprostheses (including neural devices and joint replacements), and exopro-stheses. The biohybrid limb maximizes biological function and functional articulations with optimized hu-manprosthesis interfaces. Our long-term goals are to create biomimetic prostheses, optimized control systems for pros-theses, and optimized human-prosthesis interfaces using both limb lengthening and osseointegration techniques.

(далее…)

Категория: Научные статьи | Нет комментариев »