Hewitt, Manuel

[["dc.bibliographiccitation.firstpage","557"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Restorative Neurology and Neuroscience"],["dc.bibliographiccitation.lastpage","569"],["dc.bibliographiccitation.volume","31"],["dc.contributor.author","Ernst, Jennifer"],["dc.contributor.author","Grundey, Jessica"],["dc.contributor.author","Hewitt, Manuel"],["dc.contributor.author","von Lewinski, Friederike"],["dc.contributor.author","Kaus, Juergen"],["dc.contributor.author","Schmalz, Thomas"],["dc.contributor.author","Rohde, Veit"],["dc.contributor.author","Liebetanz, David"],["dc.date.accessioned","2018-11-07T09:29:40Z"],["dc.date.available","2018-11-07T09:29:40Z"],["dc.date.issued","2013"],["dc.description.abstract","Purpose: Functional electrical stimulation represents an alternative to conventional and passive ankle foot orthosis (AFO) for the treatment of stroke-related drop foot. We evaluated the implantable 4-channel stimulator ActiGait, which selectively and directly stimulates the peroneal nerve. In addition, it bypasses the need for surface electrodes and cables. Methods: Walking speed (10-meter gait test, [m/s]) and walking endurance (6-minute gait test [m/6min]) of 5 patients were tested prior to, as well as 6 and 12 weeks after, the implantation of the ActiGait implantable drop foot stimulator system. In addition, ankle joint angles were assessed during specific phases of the gait cycle, i.e. initiation angle (IA) at the first contact of the foot to the floor, initial plantar flexion (IPF), dorsiflexion (DF) and final plantar flexion (FPF) in [degrees] during stance phase. The ankle joint angles were measured at baseline and 12 weeks after ActiGait implantation. Results: At the first follow-up, patients' gait speed was found to have increased (0.55; 0.77 m/s) as had walking endurance (211; 260 m). Improvement in gait speed (0.55; 0.77 m/s) and endurance (214; 248 m) was still present after 12 weeks. In addition, gait analysis after 12 weeks revealed a nearly normal physiological initiation angle (113 degrees vs 122 degrees) and an increase in the initial plantar flexion (7 degrees vs. 0 degrees). The initiation angle (IA) represents a well-suited parameter for adequate pre-positioning of the foot at the beginning of the stance phase and is necessary to prevent stumbling and falling. Furthermore, IA is identical to the maximum achieved dorsiflexion during the swing phase of gait. Thus, analysis of the IA of subjects walking with the implantable drop foot stimulator systems ActiGait is particularly useful in showing that the implantable system restores the IA towards physiological ankle movements. Conclusion: The ActiGait system increased gait speed, walking endurance and the physiology of important ankle joint kinematics. This is most likely a result of ankle dorsiflexion by active peroneal stimulation during the swing phase of gait and optimized prepositioning (IA) of the foot at the beginning of stance phase. The ActiGait system represents a therapeutic option for the treatment of patients suffering drop foot due to a cerebrovascular insult."],["dc.identifier.doi","10.3233/RNN-120283"],["dc.identifier.isi","000324262100004"],["dc.identifier.pmid","23756541"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/31099"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Ios Press"],["dc.relation.issn","0922-6028"],["dc.title","Towards physiological ankle movements with the ActiGait implantable drop foot stimulator in chronic stroke"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","056028"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Journal of Neural Engineering"],["dc.bibliographiccitation.volume","15"],["dc.contributor.author","Schmalfuss, Leonie"],["dc.contributor.author","Hahne, Janne"],["dc.contributor.author","Farina, Dario"],["dc.contributor.author","Hewitt, Manuel"],["dc.contributor.author","Kogut, Andreas"],["dc.contributor.author","Doneit, Wolfgang"],["dc.contributor.author","Reischl, Markus"],["dc.contributor.author","Rupp, Rüdiger"],["dc.contributor.author","Liebetanz, David"],["dc.date.accessioned","2020-12-10T18:15:50Z"],["dc.date.available","2020-12-10T18:15:50Z"],["dc.date.issued","2018"],["dc.identifier.doi","10.1088/1741-2552/aad727"],["dc.identifier.eissn","1741-2552"],["dc.identifier.issn","1741-2560"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/74971"],["dc.notes.intern","DOI Import GROB-354"],["dc.title","A hybrid auricular control system: direct, simultaneous, and proportional myoelectric control of two degrees of freedom in prosthetic hands"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","509"],["dc.bibliographiccitation.journal","NeuroImage"],["dc.bibliographiccitation.lastpage","517"],["dc.bibliographiccitation.volume","124"],["dc.contributor.author","Meincke, Jonna"],["dc.contributor.author","Hewitt, Manuel"],["dc.contributor.author","Batsikadze, Giorgi"],["dc.contributor.author","Liebetanz, David"],["dc.date.accessioned","2018-11-07T10:21:46Z"],["dc.date.available","2018-11-07T10:21:46Z"],["dc.date.issued","2016"],["dc.description.abstract","Background: Although neuronavigation is increasingly used for optimizing coil positioning, the inter-session reliability of hotspot location remains unsatisfactory, probably due to the variability of motor evoked potentials (MEPs) and residual investigator bias. Purpose: To increase the reliability and accuracy of hotspot location we introduce a novel automated hotspot-hunting procedure (AHH). Methods: AHH is based on resting motor thresholds (RMTs) instead of MEP amplitudes. By combining robotic coil positioning with a closed loop target search algorithm AHH runs independently from the investigator. AHH first identifies all targets with an RMT below a defined intensity of stimulator output (MEP-positive) and then locates the motor hotspot of a target muscle by measuring RMTs at all identified MEP-positive targets. Results were compared to robotic MEP amplitude TMS mapping (MAM) using a 7 x 7 predefined target grid and suprathreshold intensities and manual hotspot search (MHS). Sequence of stimulation was randomized from pulse to pulse in AHH and MAM. Each procedure was tested in 8 subjects. Results: Inter-session CoG shift was significantly reduced with AHH (1.4 mm (SEM: 0.4)) as compared to MAM (7.0 mm (SEM: 1.8)) (p=0.018) and MHS (9.6 mm (SEM: 2.2)) (p=0.007). No statistical difference was observed between MAM and MHS. RMTs were reliable between sessions. Conclusion: Our method represents the first fully automated, i.e. investigator-independent, TMS hotspot-hunting procedure. Measuring RMTs instead of MEP amplitudes leads to significantly increased accuracy and reliability of CoG locations. Moreover, by assessing thresholds AHH is the first procedure to fulfill the original hotspot definition. (C) 2015 Elsevier Inc. All rights reserved."],["dc.identifier.doi","10.1016/j.neuroimage.2015.09.013"],["dc.identifier.isi","000366646700047"],["dc.identifier.pmid","26385012"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/42150"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Academic Press Inc Elsevier Science"],["dc.relation.issn","1095-9572"],["dc.relation.issn","1053-8119"],["dc.title","Automated TMS hotspot-hunting using a closed loop threshold-based algorithm"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","e0201277"],["dc.bibliographiccitation.issue","7"],["dc.bibliographiccitation.journal","PLOS ONE"],["dc.bibliographiccitation.volume","13"],["dc.contributor.author","Meincke, Jonna"],["dc.contributor.author","Hewitt, Manuel"],["dc.contributor.author","Reischl, Markus"],["dc.contributor.author","Rupp, Rüdiger"],["dc.contributor.author","Schmidt-Samoa, Carsten"],["dc.contributor.author","Liebetanz, David"],["dc.date.accessioned","2019-07-09T11:45:46Z"],["dc.date.available","2019-07-09T11:45:46Z"],["dc.date.issued","2018"],["dc.description.abstract","BACKGROUND: Most humans have the ability to activate the auricular muscles. Although (intentional) control suggests an involvement of higher cortical centers underlying posterior auricular muscle (PAM) activation, the cortical representation of the auricular muscles is still unknown. METHODS: With the purpose of identifying a possible cortical representation area we performed automated robotic and image-guided transcranial magnetic stimulation (TMS) mapping (n = 8) and functional magnetic resonance imaging (fMRI) (n = 13). For topographical comparison, a similar experimental protocol was applied for the first dorsal interosseus muscle (FDI) of the hand. RESULTS: The calculated centers of gravity (COGs) of both muscles were located on the precentral gyrus with the PAM COGs located more laterally compared to the FDI. The distance between the mean PAM and mean FDI COG was 26.3 mm. The TMS mapping results were confirmed by fMRI, which showed a dominance of cortical activation within the precentral gyrus during the corresponding motor tasks. The correspondence of TMS and fMRI results was high. CONCLUSION: The involvement of the primary motor cortex in PAM activation might point to an evolved function of the auricular muscles in humans and/or the ability of intentional (and selective) muscle activation."],["dc.identifier.doi","10.1371/journal.pone.0201277"],["dc.identifier.pmid","30052653"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/15316"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/59310"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.relation.issn","1932-6203"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.subject.ddc","610"],["dc.title","Cortical representation of auricular muscles in humans: A robot-controlled TMS mapping and fMRI study"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","79"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Restorative Neurology and Neuroscience"],["dc.bibliographiccitation.lastpage","95"],["dc.bibliographiccitation.volume","34"],["dc.contributor.author","Schmalfuss, Leonie"],["dc.contributor.author","Rupp, R."],["dc.contributor.author","Tuga, Michele Rene"],["dc.contributor.author","Kogut, A."],["dc.contributor.author","Hewitt, M."],["dc.contributor.author","Meincke, Jonna"],["dc.contributor.author","Klinker, Florian"],["dc.contributor.author","Duttenhoefer, W."],["dc.contributor.author","Eck, U."],["dc.contributor.author","Mikut, Ralf"],["dc.contributor.author","Reischl, Markus"],["dc.contributor.author","Liebetanz, David"],["dc.date.accessioned","2018-11-07T10:21:21Z"],["dc.date.available","2018-11-07T10:21:21Z"],["dc.date.issued","2016"],["dc.description.abstract","Purpose: Providing mobility solutions for individuals with tetraplegia remains challenging. Existing control devices have shortcomings such as varying or poor signal quality or interference with communication. To overcome these limitations, we present a novel myoelectric auricular control system (ACS) based on bilateral activation of the posterior auricular muscles (PAMs). Methods: Ten able-bodied subjects and two individuals with tetraplegia practiced PAM activation over 4 days using visual feedback and software-based training for 1 h/day. Initially, half of these subjects were not able to voluntarily activate their PAMs. This ability was tested with regard to 8 parameters such as contraction rate, lateralized activation, wheelchair speed and path length in a virtual obstacle course. In session 5, all subjects steered an electric wheelchair with the ACS. Results: Performance of all subjects in controlling their PAMs improved steadily over the training period. By day 5, all subjects successfully generated basic steering commands using the ACS in a powered wheelchair, and subjects with tetraplegia completed a complex real-world obstacle course. This study demonstrates that the ability to activate PAM on both sides together or unilaterally can be learned and used intuitively to steer a wheelchair. Conclusions: With the ACS we can exploit the untapped potential of the PAMs by assigning them a new, complex function. The inherent advantages of the ACS, such as not interfering with oral communication, robustness, stability over time and proportional and continuous signal generation, meet the specific needs of wheelchair users and render it a realistic alternative to currently available assistive technologies."],["dc.identifier.doi","10.3233/RNN-150579"],["dc.identifier.isi","000368632700007"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/42066"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Ios Press"],["dc.relation.issn","1878-3627"],["dc.relation.issn","0922-6028"],["dc.title","Steer by ear: Myoelectric auricular control of powered wheelchairs for individuals with spinal cord injury"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]