Muceli, Silvia

[["dc.bibliographiccitation.firstpage","365"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Journal of Applied Physiology"],["dc.bibliographiccitation.lastpage","376"],["dc.bibliographiccitation.volume","118"],["dc.contributor.author","Dideriksen, Jakob Lund"],["dc.contributor.author","Muceli, Silvia"],["dc.contributor.author","Dosen, Strahinja"],["dc.contributor.author","Laine, C. M."],["dc.contributor.author","Farina, Dario"],["dc.date.accessioned","2018-11-07T10:01:36Z"],["dc.date.available","2018-11-07T10:01:36Z"],["dc.date.issued","2015"],["dc.description.abstract","Neuromuscular electrical stimulation (NMES) is commonly used in rehabilitation, but electrically evoked muscle activation is in several ways different from voluntary muscle contractions. These differences lead to challenges in the use of NMES for restoring muscle function. We investigated the use of low-current, high-frequency nerve stimulation to activate the muscle via the spinal motoneuron (MN) pool to achieve more natural activation patterns. Using a novel stimulation protocol, the H-reflex responses to individual stimuli in a train of stimulation pulses at 100 Hz were reliably estimated with surface EMG during low-level contractions. Furthermore, single motor unit recruitment by afferent stimulation was analyzed with intramuscular EMG. The results showed that substantially elevated H-reflex responses were obtained during 100-Hz stimulation with respect to a lower stimulation frequency. Furthermore, motor unit recruitment using 100-Hz stimulation was not fully synchronized, as it occurs in classic NMES, and the discharge rates differed among motor units because each unit was activated only after a specific number of stimuli. The most likely mechanism behind these observations is the temporal summation of subthreshold excitatory postsynaptic potentials from Ia fibers to the MNs. These findings and their interpretation were also verified by a realistic simulation model of afferent stimulation of a MN population. These results suggest that the proposed stimulation strategy may allow generation of considerable levels of muscle activation by motor unit recruitment that resembles the physiological conditions."],["dc.description.sponsorship","European Union Commission through the project NeuroTREMOR [287739]"],["dc.identifier.doi","10.1152/japplphysiol.00327.2014"],["dc.identifier.isi","000349245900013"],["dc.identifier.pmid","25477350"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/38055"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Physiological Soc"],["dc.relation.issn","1522-1601"],["dc.relation.issn","8750-7587"],["dc.title","Physiological recruitment of motor units by high-frequency electrical stimulation of afferent pathways"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1041"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","IEEE Transactions on Neural Systems and Rehabilitation Engineering"],["dc.bibliographiccitation.lastpage","1052"],["dc.bibliographiccitation.volume","22"],["dc.contributor.author","Ninu, Andrei"],["dc.contributor.author","Dosen, Strahinja"],["dc.contributor.author","Muceli, Silvia"],["dc.contributor.author","Rattay, Frank"],["dc.contributor.author","Dietl, Hans"],["dc.contributor.author","Farina, Dario"],["dc.date.accessioned","2018-11-07T09:35:56Z"],["dc.date.available","2018-11-07T09:35:56Z"],["dc.date.issued","2014"],["dc.description.abstract","In closed-loop control of grasping by hand prostheses, the feedback information sent to the user is usually the actual controlled variable, i.e., the grasp force. Although this choice is intuitive and logical, the force production is only the last step in the process of grasping. Therefore, this study evaluated the performance in controlling grasp strength using a hand prosthesis operated through a complete grasping sequence while varying the feedback variables (e. g., closing velocity, grasping force), which were provided to the user visually or through vibrotactile stimulation. The experiments were conducted on 13 volunteers who controlled the Otto Bock Sensor Hand Speed prosthesis. Results showed that vibrotactile patterns were able to replace the visual feedback. Interestingly, the experiments demonstrated that direct force feedback was not essential for the control of grasping force. The subjects were indeed able to control the grip strength, predictively, by estimating the grasping force from the prosthesis velocity of closing. Therefore, grasping without explicit force feedback is not completely blind, contrary to what is usually assumed. In our study we analyzed grasping with a specific prosthetic device, but the outcomes are also applicable for other devices, with one or more degrees-of-freedom. The necessary condition is that the electromyography (EMG) signal directly and proportionally controls the velocity/grasp force of the hand, which is a common approach among EMG controlled prosthetic devices. The results provide important indications on the design of closed-loop EMG controlled prosthetic systems."],["dc.identifier.doi","10.1109/TNSRE.2014.2318431"],["dc.identifier.isi","000342080400016"],["dc.identifier.pmid","24801625"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/32497"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Ieee-inst Electrical Electronics Engineers Inc"],["dc.relation.issn","1558-0210"],["dc.relation.issn","1534-4320"],["dc.title","Closed-Loop Control of Grasping With a Myoelectric Hand Prosthesis: Which Are the Relevant Feedback Variables for Force Control?"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","385"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","IEEE Transactions on Neural Systems and Rehabilitation Engineering"],["dc.bibliographiccitation.lastpage","395"],["dc.bibliographiccitation.volume","23"],["dc.contributor.author","Dosen, Strahinja"],["dc.contributor.author","Muceli, Silvia"],["dc.contributor.author","Dideriksen, Jakob Lund"],["dc.contributor.author","Pablo Romero, Juan"],["dc.contributor.author","Rocon, Eduardo"],["dc.contributor.author","Pons, Jose L."],["dc.contributor.author","Farina, Dario"],["dc.date.accessioned","2018-11-07T09:57:42Z"],["dc.date.available","2018-11-07T09:57:42Z"],["dc.date.issued","2015"],["dc.description.abstract","Tremor is one of the most prevalent movement disorders. There is a large proportion of patients (around 25%) in whom current treatments do not attain a significant tremor reduction. This paper proposes a tremor suppression strategy that detects tremor from the electromyographic signals of the muscles from which tremor originates and counteracts it by delivering electrical stimulation to the antagonist muscles in an out of phase manner. The detection was based on the iterative Hilbert transform and stimulation was delivered above the motor threshold (motor stimulation) and below the motor threshold (sensory stimulation). The system was tested on six patients with predominant wrist flexion/extension tremor (four with Parkinson disease and two with Essential tremor) and led to an average tremor reduction in the range of 46%-81% and 35%-48% across five patients when using the motor and sensory stimulation, respectively. In one patient, the system did not attenuate tremor. These results demonstrate that tremor attenuation might be achieved by delivering electrical stimulation below the motor threshold, preventing muscle fatigue and discomfort for the patients, which sets the basis for the development of an alternative treatment for tremor."],["dc.description.sponsorship","Commission of the European Union [ICT-2011-287739]"],["dc.identifier.doi","10.1109/TNSRE.2014.2328296"],["dc.identifier.isi","000354467200006"],["dc.identifier.pmid","25051555"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/37220"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Ieee-inst Electrical Electronics Engineers Inc"],["dc.relation.issn","1558-0210"],["dc.relation.issn","1534-4320"],["dc.title","Online Tremor Suppression Using Electromyography and Low-Level Electrical Stimulation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]