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© 2015 Gonzalez-Vargas et al., Modern assistive devices are very sophisticated systems with multiple degrees of freedom. However, an effective and user-friendly control of these systems is still an open problem since conventional human-machine interfaces (HMI) cannot easily accommodate the system’s complexity. In HMIs, the user is responsible for generating unique patterns of command signals directly triggering the device functions. This approach can be difficult to implement when there are many functions (necessitating many command patterns) and/or the user has a considerable impairment (limited number of available signal sources). In this study, we propose a novel concept for a general-purpose HMI where the controller and the user communicate bidirectionally to select the desired function. The system first presents possible choices to the user via electro-tactile stimulation; the user then acknowledges the desired choice by generating a single command signal. Therefore, the proposed approach simplifies the user communication interface (one signal to generate), decoding (one signal to recognize), and allows selecting from a number of options. To demonstrate the new concept the method was used in one particular application, namely, to implement the control of all the relevant functions in a state of the art commercial prosthetic hand without using any myoelectric channels. We performed experiments in healthy subjects and with one amputee to test the feasibility of the novel approach. The results showed that the performance of the novel HMI concept was comparable or, for some outcome measures, better than the classic myoelectric interfaces. The presented approach has a general applicability and the obtained results point out that it could be used to operate various assistive systems (e.g., prosthesis vs. wheelchair), or it could be integrated into other control schemes (e.g., myoelectric control, brain-machine interfaces) in order to improve the usability of existing low-bandwidth HMIs., This work was supported by the Japanese Society for Promotion of Science (JSPS) Grant for Researcher Dispatch Program-International Network of Advanced Medical Engineering using Bio-robotics Technology (2009-2012), European Commission under the MYOSENS (FP7-PEOPLE-2011-IAPP-286208) project and by the German Ministry for Education and Research (BMBF) via the Bernstein Focus Neurotechnology (BFNT) Gottingen under Grant 01GQ0810.

Background Active hand prostheses controlled using electromyography (EMG) signals have been used for decades to restore the grasping function, lost after an amputation. Although myocontrol is a simple and intuitive interface, it is also imprecise due to the stochastic nature of the EMG recorded using surface electrodes. Furthermore, the sensory feedback from the prosthesis to the user is still missing. In this study, we present a novel concept to close the loop in myoelectric prostheses. In addition to conveying the grasping force (system output), we provided to the user the online information about the system input (EMG biofeedback). Methods As a proof-of-concept, the EMG biofeedback was transmitted in the current study using a visual interface (ideal condition). Ten able-bodied subjects and two amputees controlled a state-of-the-art myoelectric prosthesis in routine grasping and force steering tasks using EMG and force feedback (novel approach) and force feedback only (classic approach). The outcome measures were the variability of the generated forces and absolute deviation from the target levels in the routine grasping task, and the root mean square tracking error and the number of sudden drops in the force steering task. Results During the routine grasping, the novel method when used by able-bodied subjects decreased twofold the force dispersion as well as absolute deviations from the target force levels, and also resulted in a more accurate and stable tracking of the reference force profiles during the force steering. Furthermore, the force variability during routine grasping did not increase for the higher target forces with EMG biofeedback. The trend was similar in the two amputees. Conclusions The study demonstrated that the subjects, including the two experienced users of a myoelectric prosthesis, were able to exploit the online EMG biofeedback to observe and modulate the myoelectric signals, generating thereby more consistent commands. This allowed them to control the force predictively (routine grasping) and with a finer resolution (force steering). The future step will be to implement this promising and simple approach using an electrotactile interface. A prosthesis with a reliable response, following faithfully user intentions, would improve the utility during daily-life use and also facilitate the embodiment of the assistive system. peerReviewed

One of the hottest topics in rehabilitation robotics is that of proper control of prosthetic devices. Despite decades of research, the state of the art is dramatically behind the expectations. To shed light on this issue, in June, 2013 the first international workshop on Present and future of non-invasive peripheral nervous system (PNS) Machine Interfaces (MI; PMI) was convened, hosted by the International Conference on Rehabilitation Robotics. The keyword PMI has been selected to denote human-machine interfaces targeted at the limb-deficient, mainly upper-limb amputees, dealing with signals gathered from the PNS in a non-invasive way, that is, from the surface of the residuum. The workshop was intended to provide an overview of the state of the art and future perspectives of such interfaces; this paper represents is a collection of opinions expressed by each and every researcher/group involved in it.

Consejo Superior de Investigaciones Científicas (CSIC), Georg-August-Universität Göttingen Stiftung Öffentlichen Rechts Universitätsmedizin, B1 Patente sin examen previo

Method and neuroprosthetic device for monitoring and sup pression of pathological tremors in a user through the neuro stimulation of the afferent pathways to the brain, which com prises wearable elements placed over the parts of the body affected by tremor, wherein said wearable elements (1) have sensors selected from bioelectric sensors (3) generating a bioelectrical signal characterization of tremor, biomechanical sensors (4) generating a biomechanical signal characteriza tion of tremor and a combination thereof, a programmable electronic device (9) comprised of a control, acquisition and processing module of the characterization signals, and a sig nal generator for the afferent stimulation based on the bio electrical, biomechanical or combination of both signal char acterization and stimulation electrodes (8) which transmit the neuromodulation signals to the afferent pathways projecting into the central nervous system to modulate the activity of the neural structures responsible for tremor generation., Consejo Superior de Investigaciones Científicas (España), Georg-August-Universität Göttingen, A1 Solicitud de patente con informe sobre el estado de la técnica

Método y dispositivo neuroprotésico para el monitoreo y la supresión de los temblores patológicos en un usuario a través de la neuroestimulación de las vías aferentes hacia el cerebro, que comprende elementos portátiles colocados sobre las partes del cuerpo afectados por el temblor, en el que dichos elementos portátiles (1) tienen sensores bioeléctricos. (3) Generación de una primera caracterización de señal de temblor, sensores biomecánicos (4) Generación de una segunda caracterización de señal de temblor, un dispositivo electrónico programable (9) compuesto por un módulo de control, adquisición y procesamiento de las señales de caracterización de primera y segunda, y un Generador de señal para la estimulación aferente basada en la primera y segunda caracterización de la señal y electrodos de estimulación (8) que transmiten las señales de neuromodulación a las vías aferentes que se proyectan en el sistema nervioso central para modular la actividad de las estructuras neuronales responsables de la generación de temblores., Consejo Superior de Investigaciones Científicas (CSIC), Georg-August-Universität Göttingen Stiftung Öffentlichen Rechts Universitätsmedizin, T3 Traducción de patente europea

International audience; One possible method for restoring motion of paralyzed limbs is Functional Electrical Stimulation. FES can be applied in early phase of hemiplegia in order to control the affected leg while walking. FES was shown to be a valuable method for training that likely allows the user to walk later on without assistance. Rehabilitation centres mostly use preprogrammed stimulation patterns empirically obtained and manually triggered. The stimulation pattern and timing need to be set and online adapt to optimize the use of preserved capabilities and lead to symmetrical gait. We present an approach based on three phases. First an optimal control based on individually customized model is used to create the basic reference stimulation pattern for the deficient leg. Secondly, the plant is modeled as a nonlinear oscillator. Finally, the oscillator is triggered from the detection of the gait cycle phase assessed via a sensor placed on the healthy leg.