2010
Ambrosini, E; Pedrocchi, A; Schauer, T; Nahrstaedt, H; Mazzocchio, R
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 031, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISSN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - non invasive 2, Controls, Sensors
@inproceedings{IFESS2010_031b,
title = {Automatic real time procedure for adjusting the stimulus intensities to ensure reliable measurements of the H-re ex recruitment curve},
author = {E Ambrosini and A Pedrocchi and T Schauer and H Nahrstaedt and R Mazzocchio},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
issn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {031},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {Variability in the H-reflex can make it difficult to identify significant changes using traditional analysis techniques. This study presents an automatic real time procedure to adjust tibial nerve stimulus intensities to ensure reliable soleus Hreflex measurements. The procedure consists of 3 steps: (1) an acquisition of a full recruitment curve (RC); (2) a sigmoidal fitting of the ascending limb of the H-reflex RC to compute stimulus intensities needed to evoke the maximal H amplitude (Hmax) and the 50% of Hmax (H50); (3) reliable repeated-measurements of both Hmax and H50. Furthermore, the procedure can detect when changes in the H-reflex RC occur and redetermine the optimal stimulation intensities. Tests on one healthy subject were carried out both at rest and during voluntary contraction of the triceps surae muscle to provide a first validation of the procedure reliability. Significant differences were found between the 2 experimental conditions in the amplitudes of Hmax and H50 and in the homosynaptic depression, as found in literature. The procedure may be used at rest, during muscle contractions and could be particularly useful in prolonged experiments or after fatiguing exercises. Between-day and inter-subjects analyses will be next performed to fully validate the procedure.},
keywords = {Algorithms - non invasive 2, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
Variability in the H-reflex can make it difficult to identify significant changes using traditional analysis techniques. This study presents an automatic real time procedure to adjust tibial nerve stimulus intensities to ensure reliable soleus Hreflex measurements. The procedure consists of 3 steps: (1) an acquisition of a full recruitment curve (RC); (2) a sigmoidal fitting of the ascending limb of the H-reflex RC to compute stimulus intensities needed to evoke the maximal H amplitude (Hmax) and the 50% of Hmax (H50); (3) reliable repeated-measurements of both Hmax and H50. Furthermore, the procedure can detect when changes in the H-reflex RC occur and redetermine the optimal stimulation intensities. Tests on one healthy subject were carried out both at rest and during voluntary contraction of the triceps surae muscle to provide a first validation of the procedure reliability. Significant differences were found between the 2 experimental conditions in the amplitudes of Hmax and H50 and in the homosynaptic depression, as found in literature. The procedure may be used at rest, during muscle contractions and could be particularly useful in prolonged experiments or after fatiguing exercises. Between-day and inter-subjects analyses will be next performed to fully validate the procedure.
Alon, G; Roys, S; Gullapalli, R
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 035, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISSN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - non invasive 2, Controls, Sensors
@inproceedings{IFESS2010_035b,
title = {Can non-invasive electrical stimulation of the brain (ESB) modify the resting-state functional connectivity of the motor cortex? A proof of concept fMRI study},
author = {G Alon and S Roys and R Gullapalli},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
issn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {035},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {none},
keywords = {Algorithms - non invasive 2, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
none
Luo, R; Norton, J; Donaldson, N
Can the coherence between two EMG signals be used to measure the voluntary drive in paretic muscles? Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 026, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISSN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - non invasive 1, Controls, Sensors
@inproceedings{IFESS2010_026b,
title = {Can the coherence between two EMG signals be used to measure the voluntary drive in paretic muscles?},
author = {R Luo and J Norton and N Donaldson},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
issn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {026},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {Coherence is found in EMG-EMG signals during voluntary contraction of the muscles that work synergistically. This is resultant from the shared drive of motor units to the different motorneuron pools [1]. We would like to study the relationship of EMG signals between different muscle pairs during FES cycling using the coherence analysis. The hypothesis is that the frequency at which the coherence between two synergistically activated muscles peaks is related to the voluntary drive and is not influenced by the stimulation with suitable frequency. If that is the case, coherence can then serve as an indication of presence of voluntary drive and could be used for feedback control of FES cycling.},
keywords = {Algorithms - non invasive 1, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
Coherence is found in EMG-EMG signals during voluntary contraction of the muscles that work synergistically. This is resultant from the shared drive of motor units to the different motorneuron pools [1]. We would like to study the relationship of EMG signals between different muscle pairs during FES cycling using the coherence analysis. The hypothesis is that the frequency at which the coherence between two synergistically activated muscles peaks is related to the voluntary drive and is not influenced by the stimulation with suitable frequency. If that is the case, coherence can then serve as an indication of presence of voluntary drive and could be used for feedback control of FES cycling.
Jensen, W; Nielsen, M V; Ottesen, K J G; Fjeldborg, L C
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 043, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISSN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - invasive, Controls, Sensors
@inproceedings{IFESS2010_043b,
title = {Characterization of peri-infarct, intra-cortical motor cortex responses during reaching task in a chronic animal model of ischemic stroke},
author = {W Jensen and M V Nielsen and K J G Ottesen and L C Fjeldborg},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
issn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {043},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {Stroke is a leading cause of disability and mortality worldwide. Neuroplasticity is believed to play a key role in functional recovery. Our objective was to characterize the long-term e?ect of ischemic stroke on intra-cortical responses obtained from the motor cortex (i.e. the prenumbra zone). Two Sprague-Dawley rats were instrumented with a 16-ch electrode array. Animals were trained to reach and retrieve food pellets. Intra-cortical responses were obtained during behavioral training sessions. Computed PSTH responses revealed similar trends between the animals, i.e we observed an increase in cortical activity in a 150-300 ms interval related to the reaching task (day 0, before ischemic onset), that modulated in both amplitude and time after ischemic onset (decreased activity at Day 4 and 5, increased activity at Day 7). Variability across animals should be expected and must be investigated further. A better understanding of the effect of stroke on motor terns may assist to a better understanding of the plasticity mechanisms involved in functional recovery in the future.},
keywords = {Algorithms - invasive, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
Stroke is a leading cause of disability and mortality worldwide. Neuroplasticity is believed to play a key role in functional recovery. Our objective was to characterize the long-term e?ect of ischemic stroke on intra-cortical responses obtained from the motor cortex (i.e. the prenumbra zone). Two Sprague-Dawley rats were instrumented with a 16-ch electrode array. Animals were trained to reach and retrieve food pellets. Intra-cortical responses were obtained during behavioral training sessions. Computed PSTH responses revealed similar trends between the animals, i.e we observed an increase in cortical activity in a 150-300 ms interval related to the reaching task (day 0, before ischemic onset), that modulated in both amplitude and time after ischemic onset (decreased activity at Day 4 and 5, increased activity at Day 7). Variability across animals should be expected and must be investigated further. A better understanding of the effect of stroke on motor terns may assist to a better understanding of the plasticity mechanisms involved in functional recovery in the future.
Merrill, D; Lockhart, J; Troyk, P; Weir, R; Hankin, D
Development of an Implantable Myoelectric Sensor for Advanced Prosthesis Control Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 038, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISSN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - invasive, Controls, Sensors
@inproceedings{IFESS2010_038b,
title = {Development of an Implantable Myoelectric Sensor for Advanced Prosthesis Control},
author = {D Merrill and J Lockhart and P Troyk and R Weir and D Hankin},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
issn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {038},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {Modern hand and wrist prostheses afford a high level of mechanical sophistication, but the ability to control them in an intuitive and repeatable manner lags. Commercially-available systems using surface electromyographic (EMG) or myoelectric-control can supply at best two degrees-of-freedom (DOF), most often sequentially controlled. This limitation is partially due to the nature of surface-recorded EMG, for which the signal contains components from multiple muscle sources. We report here on the development of an implantable myoelectric sensor (IMES) using EMG sensors that can be chronically implanted into an amputee's residual muscles. Because sensing occurs at the source of muscle contraction, a single principal component of EMG is detected by each sensor, corresponding to intent to move a particular effector. This system can potentially provide independent signal sources for control of individual effectors within a limb prosthesis. The use of implanted devices supports inter-day signal repeatability. We report on efforts in preparation for human clinical trials, including animal testing, and a first-in-human proof of principal demonstration where the subject was able to intuitively and simultaneously control two DOF in a hand and wrist prosthesis.},
keywords = {Algorithms - invasive, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
Modern hand and wrist prostheses afford a high level of mechanical sophistication, but the ability to control them in an intuitive and repeatable manner lags. Commercially-available systems using surface electromyographic (EMG) or myoelectric-control can supply at best two degrees-of-freedom (DOF), most often sequentially controlled. This limitation is partially due to the nature of surface-recorded EMG, for which the signal contains components from multiple muscle sources. We report here on the development of an implantable myoelectric sensor (IMES) using EMG sensors that can be chronically implanted into an amputee's residual muscles. Because sensing occurs at the source of muscle contraction, a single principal component of EMG is detected by each sensor, corresponding to intent to move a particular effector. This system can potentially provide independent signal sources for control of individual effectors within a limb prosthesis. The use of implanted devices supports inter-day signal repeatability. We report on efforts in preparation for human clinical trials, including animal testing, and a first-in-human proof of principal demonstration where the subject was able to intuitively and simultaneously control two DOF in a hand and wrist prosthesis.
Arnold, D; Faenger, B; Huebner, A; Scholle, H. Ch.
EMG recordings of triceps brachii muscle in rats during downhill locomotion Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 040, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISSN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - invasive, Controls, Sensors
@inproceedings{IFESS2010_040b,
title = {EMG recordings of triceps brachii muscle in rats during downhill locomotion},
author = {D Arnold and B Faenger and A Huebner and H.Ch. Scholle},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
issn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {040},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {With the presented study a data base is being built which should allow the comparison of EMG data of the triceps muscle of rats before and after training and / or electrostimulation. The triceps brachii muscle of rats showed strong activities during the stance phases of the foreleg. The muscle consists of a medial, lateral and long head. The medial head is covered by the two other heads and was not further examined in this study. The triceps brachii muscle in general is well investigated. The distribution of the different fibre types (von Mering & Fischer 1999) and the position of its motoneurons (Lucas-Osma & Collazos-Castro 2009) as well as the activation pattern for walking on a horizontal treadmill (Biedermann et al. 2000, Scholle et al. 2001 and Schumann et al. 2002) are sufficiently known. Furthermore the point of electrical sensitivity was identified with a new developed intramuscular multi-channel electrode (Faenger et al. 2009). In the presented study this electrode (MED-El) was used for investigations of the activation pattern during downhill locomotion on a motor driven treadmill. The activity of the long head reached a maximum before and during touch down of the hind limb, which is in contrast to normal locomotion. An additional activation peak was also observed in the lateral head directly after touch down. The modified motor control reflects in the different activation pattern. This could be explained with the changed acting forces.},
keywords = {Algorithms - invasive, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
With the presented study a data base is being built which should allow the comparison of EMG data of the triceps muscle of rats before and after training and / or electrostimulation. The triceps brachii muscle of rats showed strong activities during the stance phases of the foreleg. The muscle consists of a medial, lateral and long head. The medial head is covered by the two other heads and was not further examined in this study. The triceps brachii muscle in general is well investigated. The distribution of the different fibre types (von Mering & Fischer 1999) and the position of its motoneurons (Lucas-Osma & Collazos-Castro 2009) as well as the activation pattern for walking on a horizontal treadmill (Biedermann et al. 2000, Scholle et al. 2001 and Schumann et al. 2002) are sufficiently known. Furthermore the point of electrical sensitivity was identified with a new developed intramuscular multi-channel electrode (Faenger et al. 2009). In the presented study this electrode (MED-El) was used for investigations of the activation pattern during downhill locomotion on a motor driven treadmill. The activity of the long head reached a maximum before and during touch down of the hind limb, which is in contrast to normal locomotion. An additional activation peak was also observed in the lateral head directly after touch down. The modified motor control reflects in the different activation pattern. This could be explained with the changed acting forces.
Malik, N A; Chappell, P H; Wood, D; Taylor, P
Event Detection for Gluteal or Hamstring Stimulation During Walking in Neurological Patients Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 025, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISSN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - non invasive 1, Controls, Sensors
@inproceedings{IFESS2010_025b,
title = {Event Detection for Gluteal or Hamstring Stimulation During Walking in Neurological Patients},
author = {N A Malik and P H Chappell and D Wood and P Taylor},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
issn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {025},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {An algorithm to detect when the tibia is vertical is presented. Its intended use is to trigger a functional electrical stimulation (FES) device for either the rotation or extension of the hip (gluteal stimulation) or flexion of the knee (hamstring stimulation) in neurological patients. The algorithm comprises a correlation coefficient calculation and a set of threshold rules. Data from a healthy subject has been used as a sample window for the correlation coefficient calculation for all the neurological patients. The sample window chosen detects correctly the events in five out of seven patients. For one patient, a sample window selected from the same patient data has been used successfully in the detection. All the results have showed no missing events during walking when compared to a footswitch.},
keywords = {Algorithms - non invasive 1, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
An algorithm to detect when the tibia is vertical is presented. Its intended use is to trigger a functional electrical stimulation (FES) device for either the rotation or extension of the hip (gluteal stimulation) or flexion of the knee (hamstring stimulation) in neurological patients. The algorithm comprises a correlation coefficient calculation and a set of threshold rules. Data from a healthy subject has been used as a sample window for the correlation coefficient calculation for all the neurological patients. The sample window chosen detects correctly the events in five out of seven patients. For one patient, a sample window selected from the same patient data has been used successfully in the detection. All the results have showed no missing events during walking when compared to a footswitch.
Maciejasz, M; Marcol, W; Paśniczek, R; Doerge, T
An experimental setup for stimulation selectivity measurement - variability of the muscle responses to the constant stimulus Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 039, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISSN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - invasive, Controls, Sensors
@inproceedings{IFESS2010_039b,
title = {An experimental setup for stimulation selectivity measurement - variability of the muscle responses to the constant stimulus},
author = {M Maciejasz and W Marcol and R Paśniczek and T Doerge},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
issn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {039},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {Selective nerve stimulation may allow decreasing an invasiveness of procedures aiming at restoration of the sensory and motor function lost due to neurological disorders or injuries. The beneficial application of selective stimulation in medicine is however often hindered by duration of procedures necessary for the setting of the stimulation parameters. To find a method allowing for quick determination of the stimulation parameters producing a specified response, an experimental setup has been developed. The setup comprises a programmable current stimulator with signal analyzer and computer with experimental software that controls the operation of the stimulator and processes signals (EMG, ENG, force, displacement, etc.) recorded in response to the stimulation. To verify the reliability of the system, preliminary experiments on rats have been conducted. The sciatic nerve has been stimulated with the use of a 12-polar cuff electrode. A MEMS gyroscope has been attached to the paw. The value of the rats paw's angular displacement in response to the stimulation has been used as an indicator of muscle response to the stimulation. A series of various stimuli have been generated three times. During each series, each stimulus was repeated three times. Intra- and inter-series response variability for each stimulus has been calculated. The inter-series variability of responses to the same stimulus was significant and higher than intra-series variability. However, the spectra of all responses recorded during each series were similar. It has been also observed that stimuli of various duration and amplitude, but same charge per phase and stimulation contacts combination, produced similar responses. The variability of the muscle response to the constant stimulus may have both technical and physiological causes. In practical application, e.g. neuroprostheses, this variability may be difficult to be avoided. Therefore, close-loop control of stimulation parameters may be necessary in order to precisely control activation level of effectors by selective stimulation of nerve fibres.},
keywords = {Algorithms - invasive, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
Selective nerve stimulation may allow decreasing an invasiveness of procedures aiming at restoration of the sensory and motor function lost due to neurological disorders or injuries. The beneficial application of selective stimulation in medicine is however often hindered by duration of procedures necessary for the setting of the stimulation parameters. To find a method allowing for quick determination of the stimulation parameters producing a specified response, an experimental setup has been developed. The setup comprises a programmable current stimulator with signal analyzer and computer with experimental software that controls the operation of the stimulator and processes signals (EMG, ENG, force, displacement, etc.) recorded in response to the stimulation. To verify the reliability of the system, preliminary experiments on rats have been conducted. The sciatic nerve has been stimulated with the use of a 12-polar cuff electrode. A MEMS gyroscope has been attached to the paw. The value of the rats paw's angular displacement in response to the stimulation has been used as an indicator of muscle response to the stimulation. A series of various stimuli have been generated three times. During each series, each stimulus was repeated three times. Intra- and inter-series response variability for each stimulus has been calculated. The inter-series variability of responses to the same stimulus was significant and higher than intra-series variability. However, the spectra of all responses recorded during each series were similar. It has been also observed that stimuli of various duration and amplitude, but same charge per phase and stimulation contacts combination, produced similar responses. The variability of the muscle response to the constant stimulus may have both technical and physiological causes. In practical application, e.g. neuroprostheses, this variability may be difficult to be avoided. Therefore, close-loop control of stimulation parameters may be necessary in order to precisely control activation level of effectors by selective stimulation of nerve fibres.
Faenger, B; Schumann, N P; Arnold, D; Grassme, R; Fischer, M S; Scholle, H. Ch.
In vivo electrical stimulation of rat triceps brachii muscle to identify intramuscular electrical sensitive points Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 041, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISSN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - invasive, Controls, Sensors
@inproceedings{IFESS2010_041b,
title = {In vivo electrical stimulation of rat triceps brachii muscle to identify intramuscular electrical sensitive points},
author = {B Faenger and N P Schumann and D Arnold and R Grassme and M S Fischer and H.Ch. Scholle},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
issn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {041},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {Earlier studies aim at a precise characterisation of intramuscularly varying recruitment patterns within M. triceps brachii (Biedermann et al. 2000, Faenger et al 2006). For physiologically justified FES (functional electrical stimulation) it is a primary condition to know more about inter- and intraindividual activation patterns. To protect the delicate muscle structure we developed, in cooperation with MED-El(R), a flexible and atraumatic full silicone coated array electrode. This electrode can be used for intramuscular EMG measurements and for electrical stimulation. The aim of this study was to identify intramuscular electrically sensitive points in rat's triceps brachii muscle. Additionally Sihler's staining and EMG measurements have been used to identify and display details about the intramuscular position of the electrode plate in relation to nerve branches. Results show that the maximum time of feasible continuous stimulation varied between a few seconds and several hours, depending on the electrode plate position being the stimulation position. Positions of motor end plates do not correspond to the positions of longest excitability. Considering the histological results, pairs of electrodes which could be stimulated for a long period of time were located very close to nerves or an intramuscular plexus. Around the surfaces of the electrode plates that can hardly stimulate the muscle non or only very thin nerves can be found.},
keywords = {Algorithms - invasive, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
Earlier studies aim at a precise characterisation of intramuscularly varying recruitment patterns within M. triceps brachii (Biedermann et al. 2000, Faenger et al 2006). For physiologically justified FES (functional electrical stimulation) it is a primary condition to know more about inter- and intraindividual activation patterns. To protect the delicate muscle structure we developed, in cooperation with MED-El(R), a flexible and atraumatic full silicone coated array electrode. This electrode can be used for intramuscular EMG measurements and for electrical stimulation. The aim of this study was to identify intramuscular electrically sensitive points in rat's triceps brachii muscle. Additionally Sihler's staining and EMG measurements have been used to identify and display details about the intramuscular position of the electrode plate in relation to nerve branches. Results show that the maximum time of feasible continuous stimulation varied between a few seconds and several hours, depending on the electrode plate position being the stimulation position. Positions of motor end plates do not correspond to the positions of longest excitability. Considering the histological results, pairs of electrodes which could be stimulated for a long period of time were located very close to nerves or an intramuscular plexus. Around the surfaces of the electrode plates that can hardly stimulate the muscle non or only very thin nerves can be found.
Watanabe, T; Tagawa, Y; Shiba, N
Mapping Method Using A Super Multi-Electrical Stimulation Device Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 033, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISSN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - non invasive 2, Controls, Sensors
@inproceedings{IFESS2010_033b,
title = {Mapping Method Using A Super Multi-Electrical Stimulation Device},
author = {T Watanabe and Y Tagawa and N Shiba},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
issn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {033},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {Many functional electrical stimulation (FES) devices use surface electrical stimulation (SES). However, most such devices are unable to reproduce task-oriented motions such as pinching or flexing of individual fingers. We have reported reproduction of such motions using SES based on a mapping method that specifies the distribution of the target muscles from the skin surface. Nevertheless, mapping method presents some problems such as a lack of objective estimation and long processing time. To solve these problems, we plan to develop a new FES system that includes an auto-mapping function using acceleration sensors. We have developed a prototype system and have reproduced some motions using a stimulation device that has 192 stimulation channels.},
keywords = {Algorithms - non invasive 2, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
Many functional electrical stimulation (FES) devices use surface electrical stimulation (SES). However, most such devices are unable to reproduce task-oriented motions such as pinching or flexing of individual fingers. We have reported reproduction of such motions using SES based on a mapping method that specifies the distribution of the target muscles from the skin surface. Nevertheless, mapping method presents some problems such as a lack of objective estimation and long processing time. To solve these problems, we plan to develop a new FES system that includes an auto-mapping function using acceleration sensors. We have developed a prototype system and have reproduced some motions using a stimulation device that has 192 stimulation channels.
Ambrosini, E; Pedrocchi, A; Schauer, T; Nahrstaedt, H; Mazzocchio, R
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 031, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISBN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - non invasive 2, Controls, Sensors
@inproceedings{IFESS2010_031,
title = {Automatic real time procedure for adjusting the stimulus intensities to ensure reliable measurements of the H-re ex recruitment curve},
author = {E Ambrosini and A Pedrocchi and T Schauer and H Nahrstaedt and R Mazzocchio},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
isbn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {031},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {Variability in the H-reflex can make it difficult to identify significant changes using traditional analysis techniques. This study presents an automatic real time procedure to adjust tibial nerve stimulus intensities to ensure reliable soleus Hreflex measurements. The procedure consists of 3 steps: (1) an acquisition of a full recruitment curve (RC); (2) a sigmoidal fitting of the ascending limb of the H-reflex RC to compute stimulus intensities needed to evoke the maximal H amplitude (Hmax) and the 50% of Hmax (H50); (3) reliable repeated-measurements of both Hmax and H50. Furthermore, the procedure can detect when changes in the H-reflex RC occur and redetermine the optimal stimulation intensities. Tests on one healthy subject were carried out both at rest and during voluntary contraction of the triceps surae muscle to provide a first validation of the procedure reliability. Significant differences were found between the 2 experimental conditions in the amplitudes of Hmax and H50 and in the homosynaptic depression, as found in literature. The procedure may be used at rest, during muscle contractions and could be particularly useful in prolonged experiments or after fatiguing exercises. Between-day and inter-subjects analyses will be next performed to fully validate the procedure.},
keywords = {Algorithms - non invasive 2, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
Variability in the H-reflex can make it difficult to identify significant changes using traditional analysis techniques. This study presents an automatic real time procedure to adjust tibial nerve stimulus intensities to ensure reliable soleus Hreflex measurements. The procedure consists of 3 steps: (1) an acquisition of a full recruitment curve (RC); (2) a sigmoidal fitting of the ascending limb of the H-reflex RC to compute stimulus intensities needed to evoke the maximal H amplitude (Hmax) and the 50% of Hmax (H50); (3) reliable repeated-measurements of both Hmax and H50. Furthermore, the procedure can detect when changes in the H-reflex RC occur and redetermine the optimal stimulation intensities. Tests on one healthy subject were carried out both at rest and during voluntary contraction of the triceps surae muscle to provide a first validation of the procedure reliability. Significant differences were found between the 2 experimental conditions in the amplitudes of Hmax and H50 and in the homosynaptic depression, as found in literature. The procedure may be used at rest, during muscle contractions and could be particularly useful in prolonged experiments or after fatiguing exercises. Between-day and inter-subjects analyses will be next performed to fully validate the procedure.
Alon, G; Roys, S; Gullapalli, R
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 035, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISBN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - non invasive 2, Controls, Sensors
@inproceedings{IFESS2010_035,
title = {Can non-invasive electrical stimulation of the brain (ESB) modify the resting-state functional connectivity of the motor cortex? A proof of concept fMRI study},
author = {G Alon and S Roys and R Gullapalli},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
isbn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {035},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {none},
keywords = {Algorithms - non invasive 2, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
none
Luo, R; Norton, J; Donaldson, N
Can the coherence between two EMG signals be used to measure the voluntary drive in paretic muscles? Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 026, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISBN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - non invasive 1, Controls, Sensors
@inproceedings{IFESS2010_026,
title = {Can the coherence between two EMG signals be used to measure the voluntary drive in paretic muscles?},
author = {R Luo and J Norton and N Donaldson},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
isbn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {026},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {Coherence is found in EMG-EMG signals during voluntary contraction of the muscles that work synergistically. This is resultant from the shared drive of motor units to the different motorneuron pools [1]. We would like to study the relationship of EMG signals between different muscle pairs during FES cycling using the coherence analysis. The hypothesis is that the frequency at which the coherence between two synergistically activated muscles peaks is related to the voluntary drive and is not influenced by the stimulation with suitable frequency. If that is the case, coherence can then serve as an indication of presence of voluntary drive and could be used for feedback control of FES cycling.},
keywords = {Algorithms - non invasive 1, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
Coherence is found in EMG-EMG signals during voluntary contraction of the muscles that work synergistically. This is resultant from the shared drive of motor units to the different motorneuron pools [1]. We would like to study the relationship of EMG signals between different muscle pairs during FES cycling using the coherence analysis. The hypothesis is that the frequency at which the coherence between two synergistically activated muscles peaks is related to the voluntary drive and is not influenced by the stimulation with suitable frequency. If that is the case, coherence can then serve as an indication of presence of voluntary drive and could be used for feedback control of FES cycling.
Jensen, W; Nielsen, M V; Ottesen, K J G; Fjeldborg, L C
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 043, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISBN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - invasive, Controls, Sensors
@inproceedings{IFESS2010_043,
title = {Characterization of peri-infarct, intra-cortical motor cortex responses during reaching task in a chronic animal model of ischemic stroke},
author = {W Jensen and M V Nielsen and K J G Ottesen and L C Fjeldborg},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
isbn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {043},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {Stroke is a leading cause of disability and mortality worldwide. Neuroplasticity is believed to play a key role in functional recovery. Our objective was to characterize the long-term e?ect of ischemic stroke on intra-cortical responses obtained from the motor cortex (i.e. the prenumbra zone). Two Sprague-Dawley rats were instrumented with a 16-ch electrode array. Animals were trained to reach and retrieve food pellets. Intra-cortical responses were obtained during behavioral training sessions. Computed PSTH responses revealed similar trends between the animals, i.e we observed an increase in cortical activity in a 150-300 ms interval related to the reaching task (day 0, before ischemic onset), that modulated in both amplitude and time after ischemic onset (decreased activity at Day 4 and 5, increased activity at Day 7). Variability across animals should be expected and must be investigated further. A better understanding of the effect of stroke on motor terns may assist to a better understanding of the plasticity mechanisms involved in functional recovery in the future.},
keywords = {Algorithms - invasive, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
Stroke is a leading cause of disability and mortality worldwide. Neuroplasticity is believed to play a key role in functional recovery. Our objective was to characterize the long-term e?ect of ischemic stroke on intra-cortical responses obtained from the motor cortex (i.e. the prenumbra zone). Two Sprague-Dawley rats were instrumented with a 16-ch electrode array. Animals were trained to reach and retrieve food pellets. Intra-cortical responses were obtained during behavioral training sessions. Computed PSTH responses revealed similar trends between the animals, i.e we observed an increase in cortical activity in a 150-300 ms interval related to the reaching task (day 0, before ischemic onset), that modulated in both amplitude and time after ischemic onset (decreased activity at Day 4 and 5, increased activity at Day 7). Variability across animals should be expected and must be investigated further. A better understanding of the effect of stroke on motor terns may assist to a better understanding of the plasticity mechanisms involved in functional recovery in the future.
Merrill, D; Lockhart, J; Troyk, P; Weir, R; Hankin, D
Development of an Implantable Myoelectric Sensor for Advanced Prosthesis Control Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 038, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISBN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - invasive, Controls, Sensors
@inproceedings{IFESS2010_038,
title = {Development of an Implantable Myoelectric Sensor for Advanced Prosthesis Control},
author = {D Merrill and J Lockhart and P Troyk and R Weir and D Hankin},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
isbn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {038},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {Modern hand and wrist prostheses afford a high level of mechanical sophistication, but the ability to control them in an intuitive and repeatable manner lags. Commercially-available systems using surface electromyographic (EMG) or myoelectric-control can supply at best two degrees-of-freedom (DOF), most often sequentially controlled. This limitation is partially due to the nature of surface-recorded EMG, for which the signal contains components from multiple muscle sources. We report here on the development of an implantable myoelectric sensor (IMES) using EMG sensors that can be chronically implanted into an amputee's residual muscles. Because sensing occurs at the source of muscle contraction, a single principal component of EMG is detected by each sensor, corresponding to intent to move a particular effector. This system can potentially provide independent signal sources for control of individual effectors within a limb prosthesis. The use of implanted devices supports inter-day signal repeatability. We report on efforts in preparation for human clinical trials, including animal testing, and a first-in-human proof of principal demonstration where the subject was able to intuitively and simultaneously control two DOF in a hand and wrist prosthesis.},
keywords = {Algorithms - invasive, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
Modern hand and wrist prostheses afford a high level of mechanical sophistication, but the ability to control them in an intuitive and repeatable manner lags. Commercially-available systems using surface electromyographic (EMG) or myoelectric-control can supply at best two degrees-of-freedom (DOF), most often sequentially controlled. This limitation is partially due to the nature of surface-recorded EMG, for which the signal contains components from multiple muscle sources. We report here on the development of an implantable myoelectric sensor (IMES) using EMG sensors that can be chronically implanted into an amputee's residual muscles. Because sensing occurs at the source of muscle contraction, a single principal component of EMG is detected by each sensor, corresponding to intent to move a particular effector. This system can potentially provide independent signal sources for control of individual effectors within a limb prosthesis. The use of implanted devices supports inter-day signal repeatability. We report on efforts in preparation for human clinical trials, including animal testing, and a first-in-human proof of principal demonstration where the subject was able to intuitively and simultaneously control two DOF in a hand and wrist prosthesis.
Arnold, D; Faenger, B; Huebner, A; Scholle, H. Ch.
EMG recordings of triceps brachii muscle in rats during downhill locomotion Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 040, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISBN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - invasive, Controls, Sensors
@inproceedings{IFESS2010_040,
title = {EMG recordings of triceps brachii muscle in rats during downhill locomotion},
author = {D Arnold and B Faenger and A Huebner and H.Ch. Scholle},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
isbn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {040},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {With the presented study a data base is being built which should allow the comparison of EMG data of the triceps muscle of rats before and after training and / or electrostimulation. The triceps brachii muscle of rats showed strong activities during the stance phases of the foreleg. The muscle consists of a medial, lateral and long head. The medial head is covered by the two other heads and was not further examined in this study. The triceps brachii muscle in general is well investigated. The distribution of the different fibre types (von Mering & Fischer 1999) and the position of its motoneurons (Lucas-Osma & Collazos-Castro 2009) as well as the activation pattern for walking on a horizontal treadmill (Biedermann et al. 2000, Scholle et al. 2001 and Schumann et al. 2002) are sufficiently known. Furthermore the point of electrical sensitivity was identified with a new developed intramuscular multi-channel electrode (Faenger et al. 2009). In the presented study this electrode (MED-El) was used for investigations of the activation pattern during downhill locomotion on a motor driven treadmill. The activity of the long head reached a maximum before and during touch down of the hind limb, which is in contrast to normal locomotion. An additional activation peak was also observed in the lateral head directly after touch down. The modified motor control reflects in the different activation pattern. This could be explained with the changed acting forces.},
keywords = {Algorithms - invasive, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
With the presented study a data base is being built which should allow the comparison of EMG data of the triceps muscle of rats before and after training and / or electrostimulation. The triceps brachii muscle of rats showed strong activities during the stance phases of the foreleg. The muscle consists of a medial, lateral and long head. The medial head is covered by the two other heads and was not further examined in this study. The triceps brachii muscle in general is well investigated. The distribution of the different fibre types (von Mering & Fischer 1999) and the position of its motoneurons (Lucas-Osma & Collazos-Castro 2009) as well as the activation pattern for walking on a horizontal treadmill (Biedermann et al. 2000, Scholle et al. 2001 and Schumann et al. 2002) are sufficiently known. Furthermore the point of electrical sensitivity was identified with a new developed intramuscular multi-channel electrode (Faenger et al. 2009). In the presented study this electrode (MED-El) was used for investigations of the activation pattern during downhill locomotion on a motor driven treadmill. The activity of the long head reached a maximum before and during touch down of the hind limb, which is in contrast to normal locomotion. An additional activation peak was also observed in the lateral head directly after touch down. The modified motor control reflects in the different activation pattern. This could be explained with the changed acting forces.
Malik, N A; Chappell, P H; Wood, D; Taylor, P
Event Detection for Gluteal or Hamstring Stimulation During Walking in Neurological Patients Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 025, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISBN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - non invasive 1, Controls, Sensors
@inproceedings{IFESS2010_025,
title = {Event Detection for Gluteal or Hamstring Stimulation During Walking in Neurological Patients},
author = {N A Malik and P H Chappell and D Wood and P Taylor},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
isbn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {025},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {An algorithm to detect when the tibia is vertical is presented. Its intended use is to trigger a functional electrical stimulation (FES) device for either the rotation or extension of the hip (gluteal stimulation) or flexion of the knee (hamstring stimulation) in neurological patients. The algorithm comprises a correlation coefficient calculation and a set of threshold rules. Data from a healthy subject has been used as a sample window for the correlation coefficient calculation for all the neurological patients. The sample window chosen detects correctly the events in five out of seven patients. For one patient, a sample window selected from the same patient data has been used successfully in the detection. All the results have showed no missing events during walking when compared to a footswitch.},
keywords = {Algorithms - non invasive 1, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
An algorithm to detect when the tibia is vertical is presented. Its intended use is to trigger a functional electrical stimulation (FES) device for either the rotation or extension of the hip (gluteal stimulation) or flexion of the knee (hamstring stimulation) in neurological patients. The algorithm comprises a correlation coefficient calculation and a set of threshold rules. Data from a healthy subject has been used as a sample window for the correlation coefficient calculation for all the neurological patients. The sample window chosen detects correctly the events in five out of seven patients. For one patient, a sample window selected from the same patient data has been used successfully in the detection. All the results have showed no missing events during walking when compared to a footswitch.
Maciejasz, M; Marcol, W; Paśniczek, R; Doerge, T
An experimental setup for stimulation selectivity measurement - variability of the muscle responses to the constant stimulus Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 039, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISBN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - invasive, Controls, Sensors
@inproceedings{IFESS2010_039,
title = {An experimental setup for stimulation selectivity measurement - variability of the muscle responses to the constant stimulus},
author = {M Maciejasz and W Marcol and R Paśniczek and T Doerge},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
isbn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {039},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {Selective nerve stimulation may allow decreasing an invasiveness of procedures aiming at restoration of the sensory and motor function lost due to neurological disorders or injuries. The beneficial application of selective stimulation in medicine is however often hindered by duration of procedures necessary for the setting of the stimulation parameters. To find a method allowing for quick determination of the stimulation parameters producing a specified response, an experimental setup has been developed. The setup comprises a programmable current stimulator with signal analyzer and computer with experimental software that controls the operation of the stimulator and processes signals (EMG, ENG, force, displacement, etc.) recorded in response to the stimulation. To verify the reliability of the system, preliminary experiments on rats have been conducted. The sciatic nerve has been stimulated with the use of a 12-polar cuff electrode. A MEMS gyroscope has been attached to the paw. The value of the rats paw's angular displacement in response to the stimulation has been used as an indicator of muscle response to the stimulation. A series of various stimuli have been generated three times. During each series, each stimulus was repeated three times. Intra- and inter-series response variability for each stimulus has been calculated. The inter-series variability of responses to the same stimulus was significant and higher than intra-series variability. However, the spectra of all responses recorded during each series were similar. It has been also observed that stimuli of various duration and amplitude, but same charge per phase and stimulation contacts combination, produced similar responses. The variability of the muscle response to the constant stimulus may have both technical and physiological causes. In practical application, e.g. neuroprostheses, this variability may be difficult to be avoided. Therefore, close-loop control of stimulation parameters may be necessary in order to precisely control activation level of effectors by selective stimulation of nerve fibres.},
keywords = {Algorithms - invasive, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
Selective nerve stimulation may allow decreasing an invasiveness of procedures aiming at restoration of the sensory and motor function lost due to neurological disorders or injuries. The beneficial application of selective stimulation in medicine is however often hindered by duration of procedures necessary for the setting of the stimulation parameters. To find a method allowing for quick determination of the stimulation parameters producing a specified response, an experimental setup has been developed. The setup comprises a programmable current stimulator with signal analyzer and computer with experimental software that controls the operation of the stimulator and processes signals (EMG, ENG, force, displacement, etc.) recorded in response to the stimulation. To verify the reliability of the system, preliminary experiments on rats have been conducted. The sciatic nerve has been stimulated with the use of a 12-polar cuff electrode. A MEMS gyroscope has been attached to the paw. The value of the rats paw's angular displacement in response to the stimulation has been used as an indicator of muscle response to the stimulation. A series of various stimuli have been generated three times. During each series, each stimulus was repeated three times. Intra- and inter-series response variability for each stimulus has been calculated. The inter-series variability of responses to the same stimulus was significant and higher than intra-series variability. However, the spectra of all responses recorded during each series were similar. It has been also observed that stimuli of various duration and amplitude, but same charge per phase and stimulation contacts combination, produced similar responses. The variability of the muscle response to the constant stimulus may have both technical and physiological causes. In practical application, e.g. neuroprostheses, this variability may be difficult to be avoided. Therefore, close-loop control of stimulation parameters may be necessary in order to precisely control activation level of effectors by selective stimulation of nerve fibres.
Faenger, B; Schumann, N P; Arnold, D; Grassme, R; Fischer, M S; Scholle, H. Ch.
In vivo electrical stimulation of rat triceps brachii muscle to identify intramuscular electrical sensitive points Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 041, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISBN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - invasive, Controls, Sensors
@inproceedings{IFESS2010_041,
title = {In vivo electrical stimulation of rat triceps brachii muscle to identify intramuscular electrical sensitive points},
author = {B Faenger and N P Schumann and D Arnold and R Grassme and M S Fischer and H.Ch. Scholle},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
isbn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {041},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {Earlier studies aim at a precise characterisation of intramuscularly varying recruitment patterns within M. triceps brachii (Biedermann et al. 2000, Faenger et al 2006). For physiologically justified FES (functional electrical stimulation) it is a primary condition to know more about inter- and intraindividual activation patterns. To protect the delicate muscle structure we developed, in cooperation with MED-El(R), a flexible and atraumatic full silicone coated array electrode. This electrode can be used for intramuscular EMG measurements and for electrical stimulation. The aim of this study was to identify intramuscular electrically sensitive points in rat's triceps brachii muscle. Additionally Sihler's staining and EMG measurements have been used to identify and display details about the intramuscular position of the electrode plate in relation to nerve branches. Results show that the maximum time of feasible continuous stimulation varied between a few seconds and several hours, depending on the electrode plate position being the stimulation position. Positions of motor end plates do not correspond to the positions of longest excitability. Considering the histological results, pairs of electrodes which could be stimulated for a long period of time were located very close to nerves or an intramuscular plexus. Around the surfaces of the electrode plates that can hardly stimulate the muscle non or only very thin nerves can be found.},
keywords = {Algorithms - invasive, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
Earlier studies aim at a precise characterisation of intramuscularly varying recruitment patterns within M. triceps brachii (Biedermann et al. 2000, Faenger et al 2006). For physiologically justified FES (functional electrical stimulation) it is a primary condition to know more about inter- and intraindividual activation patterns. To protect the delicate muscle structure we developed, in cooperation with MED-El(R), a flexible and atraumatic full silicone coated array electrode. This electrode can be used for intramuscular EMG measurements and for electrical stimulation. The aim of this study was to identify intramuscular electrically sensitive points in rat's triceps brachii muscle. Additionally Sihler's staining and EMG measurements have been used to identify and display details about the intramuscular position of the electrode plate in relation to nerve branches. Results show that the maximum time of feasible continuous stimulation varied between a few seconds and several hours, depending on the electrode plate position being the stimulation position. Positions of motor end plates do not correspond to the positions of longest excitability. Considering the histological results, pairs of electrodes which could be stimulated for a long period of time were located very close to nerves or an intramuscular plexus. Around the surfaces of the electrode plates that can hardly stimulate the muscle non or only very thin nerves can be found.
Watanabe, T; Tagawa, Y; Shiba, N
Mapping Method Using A Super Multi-Electrical Stimulation Device Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 033, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISBN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - non invasive 2, Controls, Sensors
@inproceedings{IFESS2010_033,
title = {Mapping Method Using A Super Multi-Electrical Stimulation Device},
author = {T Watanabe and Y Tagawa and N Shiba},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
isbn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {033},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {Many functional electrical stimulation (FES) devices use surface electrical stimulation (SES). However, most such devices are unable to reproduce task-oriented motions such as pinching or flexing of individual fingers. We have reported reproduction of such motions using SES based on a mapping method that specifies the distribution of the target muscles from the skin surface. Nevertheless, mapping method presents some problems such as a lack of objective estimation and long processing time. To solve these problems, we plan to develop a new FES system that includes an auto-mapping function using acceleration sensors. We have developed a prototype system and have reproduced some motions using a stimulation device that has 192 stimulation channels.},
keywords = {Algorithms - non invasive 2, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
Many functional electrical stimulation (FES) devices use surface electrical stimulation (SES). However, most such devices are unable to reproduce task-oriented motions such as pinching or flexing of individual fingers. We have reported reproduction of such motions using SES based on a mapping method that specifies the distribution of the target muscles from the skin surface. Nevertheless, mapping method presents some problems such as a lack of objective estimation and long processing time. To solve these problems, we plan to develop a new FES system that includes an auto-mapping function using acceleration sensors. We have developed a prototype system and have reproduced some motions using a stimulation device that has 192 stimulation channels.
Koutsou, A; Moreno, J C; Rocon, E; Gallego, J A; Pons, J L
Output-Error Model System Identification for FES-driven control of Knee Extensor Muscles Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 030, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISBN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - non invasive 1, Controls, Sensors
@inproceedings{IFESS2010_030,
title = {Output-Error Model System Identification for FES-driven control of Knee Extensor Muscles},
author = {A Koutsou and J C Moreno and E Rocon and J A Gallego and J L Pons},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
isbn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {030},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {The biomechanical model of the lower limb musculoskeletal junaion can be useful when designing and adapting an assistive system in case of impaired control of the limbs or individual joints, eg. knee injuries, spinal cord injuries (SCI), etc. In particular, FES-driven neuroprostheses can be used to assist impaired leg function. Simple but accurate models are required as tools that assist in tuning such neuroprostheses. This work presents a methodology to identify a non-analytical model of the human knee extensors under Functional Electrical Stimulation (FES) of extensor muscles. A unique model of the swing knee extension of individml subjects is suwected to system identification, based on information provided by a knee brace instrumented with rate gyrosoopes. The model idam?cation method was tested with healthy an injured knees. The estimated knee joint velocities verify that theadapted polynomial models can be used to predict the muscle extensors permnance in a swinging leg free motion.},
keywords = {Algorithms - non invasive 1, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
The biomechanical model of the lower limb musculoskeletal junaion can be useful when designing and adapting an assistive system in case of impaired control of the limbs or individual joints, eg. knee injuries, spinal cord injuries (SCI), etc. In particular, FES-driven neuroprostheses can be used to assist impaired leg function. Simple but accurate models are required as tools that assist in tuning such neuroprostheses. This work presents a methodology to identify a non-analytical model of the human knee extensors under Functional Electrical Stimulation (FES) of extensor muscles. A unique model of the swing knee extension of individml subjects is suwected to system identification, based on information provided by a knee brace instrumented with rate gyrosoopes. The model idam?cation method was tested with healthy an injured knees. The estimated knee joint velocities verify that theadapted polynomial models can be used to predict the muscle extensors permnance in a swinging leg free motion.
Lewis, S; Glindemann, H; Russold, M F; Westendorff, S; Gail, A; Doerge, T; Hoffmann, K-P; Dietl, H
Performance of implanted multi-site EMG recording electrodes: In vivo impedance measurements and spectral analysis Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 036, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISBN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - invasive, Controls, Sensors
@inproceedings{IFESS2010_036,
title = {Performance of implanted multi-site EMG recording electrodes: In vivo impedance measurements and spectral analysis},
author = {S Lewis and H Glindemann and M F Russold and S Westendorff and A Gail and T Doerge and K-P Hoffmann and H Dietl},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
isbn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {036},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {The presented work is part of the development of a fully implantable EMG recording system for control of upper limb prosthetic devices. In the following, investigations on the usability of an implantable thin film electrode with multiple recording sites for intramuscular EMG are presented. Electrodes were implanted epimysially on the musculus deltoideus of a rhesus macaque. To our knowledge, this is the first investigation of such electrodes for muscular EMG recordings. Ingrowth was monitored by periodic impedance measurements over eight weeks after implantation. Increase of impedance plateaued after four weeks indicating a completed encapsulation of the electrodes. EMG was recorded during relaxation and reproducible voluntary contractions of the muscle. Power spectral analysis confirmed that EMG signals with a frequency content of up to 1.2 kHz could be recorded. During contraction the signal at 200 Hz was four orders of magnitude higher than during relaxation.},
keywords = {Algorithms - invasive, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
The presented work is part of the development of a fully implantable EMG recording system for control of upper limb prosthetic devices. In the following, investigations on the usability of an implantable thin film electrode with multiple recording sites for intramuscular EMG are presented. Electrodes were implanted epimysially on the musculus deltoideus of a rhesus macaque. To our knowledge, this is the first investigation of such electrodes for muscular EMG recordings. Ingrowth was monitored by periodic impedance measurements over eight weeks after implantation. Increase of impedance plateaued after four weeks indicating a completed encapsulation of the electrodes. EMG was recorded during relaxation and reproducible voluntary contractions of the muscle. Power spectral analysis confirmed that EMG signals with a frequency content of up to 1.2 kHz could be recorded. During contraction the signal at 200 Hz was four orders of magnitude higher than during relaxation.
Miura, N; Watanabe, T. andKanai
A Preliminary Study of Muscle Fatigue Evaluation Using M-waves elicited by additional pulses for Rehabilitation with FES Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 028, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISBN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - non invasive 1, Controls, Sensors
@inproceedings{IFESS2010_028,
title = {A Preliminary Study of Muscle Fatigue Evaluation Using M-waves elicited by additional pulses for Rehabilitation with FES},
author = {N Miura and T.andKanai Watanabe},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
isbn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {028},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {Early occurrence of muscle fatigue is one of problems on FES. We focused on using M-waves elicited by the additional pulses in muscle fatigue evaluation during rehabilitation training with the surface stimulation system. In this report, a preliminary test of measurement of M-waves elicited by the additional pulses was performed under the two conditions: knee extension force production under the isometric condition and knee extension angle control by fuzzy controller based on the cycle-to-cycle control. The change in M-wave elicited by the single pulse in a burst stimulation for FES was less relevant result against decrease of force production under the isometric condition and increase of burst duration under the knee extension angle control during the muscle fatiguing. The decreasing of the M-wave elicited by the 2nd pulse of a double-pulse was observed with both experiments. These results suggest that M-waves elicited by the additional pulses would provide useful information for muscle fatigue evaluation.},
keywords = {Algorithms - non invasive 1, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
Early occurrence of muscle fatigue is one of problems on FES. We focused on using M-waves elicited by the additional pulses in muscle fatigue evaluation during rehabilitation training with the surface stimulation system. In this report, a preliminary test of measurement of M-waves elicited by the additional pulses was performed under the two conditions: knee extension force production under the isometric condition and knee extension angle control by fuzzy controller based on the cycle-to-cycle control. The change in M-wave elicited by the single pulse in a burst stimulation for FES was less relevant result against decrease of force production under the isometric condition and increase of burst duration under the knee extension angle control during the muscle fatiguing. The decreasing of the M-wave elicited by the 2nd pulse of a double-pulse was observed with both experiments. These results suggest that M-waves elicited by the additional pulses would provide useful information for muscle fatigue evaluation.
Kurstjens, M; Jensen, W
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 037, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISBN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - invasive, Controls, Sensors
@inproceedings{IFESS2010_037,
title = {Selectivity of longitudinal versus transverse tripolar stimulation of median nerve in pigs using a multicontact nerve cuff electrode},
author = {M Kurstjens and W Jensen},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
isbn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {037},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {The objective of the present study was to investigate the stimulation selectivity of a multicontact cuff electrode in a large nerve animal model. A cuff electrode with 6 contacts equally spaced around the inner circumference and two outer ring contacts was acutely implanted on the median nerve in pigs. The selectivity of activation of 7 forelimb muscles when applying monophasic stimulation in the commonly used longitudinal tripolar configuration (LTC) was compared to that when using the transverse tripolar configuration (TTC). Results showed that, depending on the electrode contact, current pulse amplitude and stimulation configuration used, up to 4 muscles were activated with 100% selectivity in a single animal. Using TTC increased selectivity compared to LTC for individual muscles but not the total number of muscles that was activated selectively and larger current amplitudes were needed to obtain activation. More sophisticated stimulation paradigms capable of targeting additional fascicles located more centrally in the nerve trunk will be needed in the future to provide sufficient number of control channels for advance degree of freedom upper limb prosthetic devices.},
keywords = {Algorithms - invasive, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
The objective of the present study was to investigate the stimulation selectivity of a multicontact cuff electrode in a large nerve animal model. A cuff electrode with 6 contacts equally spaced around the inner circumference and two outer ring contacts was acutely implanted on the median nerve in pigs. The selectivity of activation of 7 forelimb muscles when applying monophasic stimulation in the commonly used longitudinal tripolar configuration (LTC) was compared to that when using the transverse tripolar configuration (TTC). Results showed that, depending on the electrode contact, current pulse amplitude and stimulation configuration used, up to 4 muscles were activated with 100% selectivity in a single animal. Using TTC increased selectivity compared to LTC for individual muscles but not the total number of muscles that was activated selectively and larger current amplitudes were needed to obtain activation. More sophisticated stimulation paradigms capable of targeting additional fascicles located more centrally in the nerve trunk will be needed in the future to provide sufficient number of control channels for advance degree of freedom upper limb prosthetic devices.
Merletti, R; Botter, A; Minetto, M A
Spinal involvement and muscle cramps in electrically-elicited muscle contractions Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 024, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISBN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - non invasive 1, Controls, Sensors
@inproceedings{IFESS2010_024,
title = {Spinal involvement and muscle cramps in electrically-elicited muscle contractions},
author = {R Merletti and A Botter and M A Minetto},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
isbn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {024},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {Electrical stimulation of innervated muscles has been investigated for many decades with alternations of high and low clinical interest in the fields of stroke, SCI rehabilitation, and sport sciences. Early work demonstrated that afferent fibers have lower thresholds and are usually activated first (therefore eliciting an H-reflex). In the case of nerve trunk stimulation, the order of recruitment is mostly conditioned by the axonal dimension and excitability threshold. In the case of muscle motor point stimulation, the spatial distribution of nerve branches plays a predominant role. Sustained stimulation produces a progressive increase of force that is often maintained in subsequent voluntary activation by stroke patients. This observation suggested a facilitation mechanism at the spinal and/or supraspinal levels. Such facilitation has been observed in healthy subjects as well, and may explain the generation of cramps elicited during stimulation and sustained for dozens of seconds after stimulation has been interrupted. The most recent interpretations of facilitation resulting from peripheral stimulation focused on pre- (potentiation of neurotransmitter release from afferent fibers) or post-synaptic (generation of "Persistent Inward Currents" in spinal motor neurons or interneurons) mechanisms. The renewed attention to these phenomena is once more increasing the interest toward electrical stimulation of the neuromuscular system. This is an opportunity for a structured investigation of the field aimed to resolving elements of confusion and controversy that still plague this area of electrophysiology.},
keywords = {Algorithms - non invasive 1, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
Electrical stimulation of innervated muscles has been investigated for many decades with alternations of high and low clinical interest in the fields of stroke, SCI rehabilitation, and sport sciences. Early work demonstrated that afferent fibers have lower thresholds and are usually activated first (therefore eliciting an H-reflex). In the case of nerve trunk stimulation, the order of recruitment is mostly conditioned by the axonal dimension and excitability threshold. In the case of muscle motor point stimulation, the spatial distribution of nerve branches plays a predominant role. Sustained stimulation produces a progressive increase of force that is often maintained in subsequent voluntary activation by stroke patients. This observation suggested a facilitation mechanism at the spinal and/or supraspinal levels. Such facilitation has been observed in healthy subjects as well, and may explain the generation of cramps elicited during stimulation and sustained for dozens of seconds after stimulation has been interrupted. The most recent interpretations of facilitation resulting from peripheral stimulation focused on pre- (potentiation of neurotransmitter release from afferent fibers) or post-synaptic (generation of "Persistent Inward Currents" in spinal motor neurons or interneurons) mechanisms. The renewed attention to these phenomena is once more increasing the interest toward electrical stimulation of the neuromuscular system. This is an opportunity for a structured investigation of the field aimed to resolving elements of confusion and controversy that still plague this area of electrophysiology.
Nielsen, T N; Sevcencu, C; Struijk, J J
Stimulation selectivity of an interfascicular electrode in the sciatic nerve of rabbits Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 042, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISBN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - invasive, Controls, Sensors
@inproceedings{IFESS2010_042,
title = {Stimulation selectivity of an interfascicular electrode in the sciatic nerve of rabbits},
author = {T N Nielsen and C Sevcencu and J J Struijk},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
isbn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {042},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {The choice of electrode for functional electrical stimulation systems is a compromise between selectivity and invasiveness; high selectivity is desirable to obtain maximum functional control, but if the surgical procedure induces too high risk the electrode will not be acceptable for human use. Current literature on peripheral nerve electrodes has focused mainly on extra-neural and intrafascicular electrodes. The current study presents a new interfascicular electrode that could simplify implantation of the electrode because it does not require the nerve to be freed of blood vessels and connective tissue. The electrode was implanted in the sciatic nerve of nine rabbits and was capable of fully activating the tibial and peroneal nerve branches with high selectivity (SI = 0.98textpm0.02, meantextpmSD) in all animals. Implantation of the electrode was simple and the interfascicular electrode could be an interesting alternative in applications where freeing the nerve is complicated by blood vessels e.g. the vagal nerve. Further studies are needed to investigate the stability and safety of the electrode in chronic experiments.},
keywords = {Algorithms - invasive, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
The choice of electrode for functional electrical stimulation systems is a compromise between selectivity and invasiveness; high selectivity is desirable to obtain maximum functional control, but if the surgical procedure induces too high risk the electrode will not be acceptable for human use. Current literature on peripheral nerve electrodes has focused mainly on extra-neural and intrafascicular electrodes. The current study presents a new interfascicular electrode that could simplify implantation of the electrode because it does not require the nerve to be freed of blood vessels and connective tissue. The electrode was implanted in the sciatic nerve of nine rabbits and was capable of fully activating the tibial and peroneal nerve branches with high selectivity (SI = 0.98textpm0.02, meantextpmSD) in all animals. Implantation of the electrode was simple and the interfascicular electrode could be an interesting alternative in applications where freeing the nerve is complicated by blood vessels e.g. the vagal nerve. Further studies are needed to investigate the stability and safety of the electrode in chronic experiments.
Kamavuako, E N; Farina, D
Stimulus-response curves: Effect of recording site and inter-electrode distance Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 027, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISBN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - non invasive 1, Controls, Sensors
@inproceedings{IFESS2010_027,
title = {Stimulus-response curves: Effect of recording site and inter-electrode distance},
author = {E N Kamavuako and D Farina},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
isbn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {027},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {This paper investigates whether the indexes of the stimulus-response (SR) curves of human motor nerves depend on the recording site and on the inter-electrode distance (5-35mm) in 18 healthy subjects. SR curves were measured by stimulating the peroneal nerve, with the compound muscle action potential (CMAP) recorded on the tibialis anterior muscle using a linear adhesive array of 8 electrodes. Each SR curve was characterized using the threshold intensity of stimulation to obtain 5, 10, 50, 90 and 95% (I5%, I10%, I50%, I90%, and I95%) of the CMAP computed on the basis of four parameters (peak, area, peak-to-peak, and total area). The results showed no significant differences between recoding sites and inter-electrode distances. Although no significant difference was found between parameters, the peak-to-peak value had the most consistent threshold intensities across inter-electrode distances. It is concluded that electrode positioning along the direction of the muscle fibers and inter-electrode distance do not have a significant influence on the characteristics of the normalized SR curve.},
keywords = {Algorithms - non invasive 1, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
This paper investigates whether the indexes of the stimulus-response (SR) curves of human motor nerves depend on the recording site and on the inter-electrode distance (5-35mm) in 18 healthy subjects. SR curves were measured by stimulating the peroneal nerve, with the compound muscle action potential (CMAP) recorded on the tibialis anterior muscle using a linear adhesive array of 8 electrodes. Each SR curve was characterized using the threshold intensity of stimulation to obtain 5, 10, 50, 90 and 95% (I5%, I10%, I50%, I90%, and I95%) of the CMAP computed on the basis of four parameters (peak, area, peak-to-peak, and total area). The results showed no significant differences between recoding sites and inter-electrode distances. Although no significant difference was found between parameters, the peak-to-peak value had the most consistent threshold intensities across inter-electrode distances. It is concluded that electrode positioning along the direction of the muscle fibers and inter-electrode distance do not have a significant influence on the characteristics of the normalized SR curve.
Watanabe, T; Fukushima, K
A Study on Feedback Error Learning Controller for FES: Generation of Target Trajectories by Minimum Jerk Model Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 034, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISBN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - non invasive 2, Controls, Sensors
@inproceedings{IFESS2010_034,
title = {A Study on Feedback Error Learning Controller for FES: Generation of Target Trajectories by Minimum Jerk Model},
author = {T Watanabe and K Fukushima},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
isbn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {034},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {In our previous studies, the Feedback Error Learning (FEL) controller was found to be applicable to FES control of wrist joint movements. However, sinusoidal trajectories were only used for the target joint angles and the artificial neural network (ANN) was trained for each trajectory. In this study, focusing on two-point reaching movement, target trajectories were generated by the minimum jerk model. In computer simulation tests, ANNs trained with different number of target trajectories under the same total number of control iteration (50 control trials) were compared. The Inverse Dynamics Model (IDM) of the controlled limb realized by the trained ANN decreased the output power of the feedback controller and improved tracking performance to unlearned target trajectories. The IDM performed well when target trajectory was changed every 1 control trial during ANN training.},
keywords = {Algorithms - non invasive 2, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
In our previous studies, the Feedback Error Learning (FEL) controller was found to be applicable to FES control of wrist joint movements. However, sinusoidal trajectories were only used for the target joint angles and the artificial neural network (ANN) was trained for each trajectory. In this study, focusing on two-point reaching movement, target trajectories were generated by the minimum jerk model. In computer simulation tests, ANNs trained with different number of target trajectories under the same total number of control iteration (50 control trials) were compared. The Inverse Dynamics Model (IDM) of the controlled limb realized by the trained ANN decreased the output power of the feedback controller and improved tracking performance to unlearned target trajectories. The IDM performed well when target trajectory was changed every 1 control trial during ANN training.
Zhang, Q; Hayashibe, M; Sablayrolles, B; Azevedo-Coste, C
Torque Prediction Based on Evoked EMG in Fatiguing Muscle Toward Advanced Drop Foot Correction Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 029, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISBN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - non invasive 1, Controls, Sensors
@inproceedings{IFESS2010_029,
title = {Torque Prediction Based on Evoked EMG in Fatiguing Muscle Toward Advanced Drop Foot Correction},
author = {Q Zhang and M Hayashibe and B Sablayrolles and C Azevedo-Coste},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
isbn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {029},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {Electrical stimulation (ES) has been applied since 1961 for the correction of hemiplegic drop foot. One main drawback of the technique is the occurrence of early fatigue. Therefore, it is essential to predict force generation for precise ES closed loop control when the stimulated muscle becomes fatigued. This work aims to predict ankle torque using stimulus evoked EMG (eEMG) during different muscle fatigue states. Five healthy subjects participated in our study. Conventional stimulation for drop foot correction was applied by surface stimulation in sitting position. The results showed that during long-term stimulation the generated torque gradually declined due to muscle fatigue, the muscle activity (EMG) performed quite differently in different fatigue level. In this work, we carried out the torque prediction with an adapted parameters model according to muscle fatigue state by reidentification using the latest measurement. The prediction was improved with 21%~90.9% comparing to the fixed parameters model. The results revealed a promising approach to use evoked EMG for fatigue compensation in the application of drop foot correction.},
keywords = {Algorithms - non invasive 1, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
Electrical stimulation (ES) has been applied since 1961 for the correction of hemiplegic drop foot. One main drawback of the technique is the occurrence of early fatigue. Therefore, it is essential to predict force generation for precise ES closed loop control when the stimulated muscle becomes fatigued. This work aims to predict ankle torque using stimulus evoked EMG (eEMG) during different muscle fatigue states. Five healthy subjects participated in our study. Conventional stimulation for drop foot correction was applied by surface stimulation in sitting position. The results showed that during long-term stimulation the generated torque gradually declined due to muscle fatigue, the muscle activity (EMG) performed quite differently in different fatigue level. In this work, we carried out the torque prediction with an adapted parameters model according to muscle fatigue state by reidentification using the latest measurement. The prediction was improved with 21%~90.9% comparing to the fixed parameters model. The results revealed a promising approach to use evoked EMG for fatigue compensation in the application of drop foot correction.
Tan, J; Zariffa, J; Vette, A; Lynch, C; Masani, K; Popovic, M
Use of an inverted pendulum apparatus for the study of closed-loop FES control of the ankle joints during quiet standing Inproceedings
In: Mandl, T; Martinek, J; Bijak, M; Lanmueller, H; Mayr, W; Pichler, M (Ed.): pp. 032, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria, Imperial Riding School, Vienna, Austria, 2010, ISBN: 978-3-900928-09-4.
Abstract | Links | BibTeX | Tags: Algorithms - non invasive 2, Controls, Sensors
@inproceedings{IFESS2010_032,
title = {Use of an inverted pendulum apparatus for the study of closed-loop FES control of the ankle joints during quiet standing},
author = {J Tan and J Zariffa and A Vette and C Lynch and K Masani and M Popovic},
editor = {T Mandl and J Martinek and M Bijak and H Lanmueller and W Mayr and M Pichler},
url = {https://ifess.org/files/proceedings/IFESS2010/IFESS2010.pdf},
isbn = {978-3-900928-09-4},
year = {2010},
date = {2010-09-01},
pages = {032},
publisher = {Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna Medical School, AKH 4L, Waehringer Guertel 18-20, A-1090 Vienna, Austria},
address = {Imperial Riding School, Vienna, Austria},
abstract = {The restoration of arm-free standing in individuals with paraplegia can be accomplished with the help of functional electrical stimulation (FES). An experimental device, the Inverted Pendulum Standing Apparatus (IPSA), is used to study closed-loop FES control of the ankle joint. The IPSA uses the ankle muscles of a sitting subject to balance an inverted pendulum that mimics the subject's body during quiet stance, thereby overcoming the safety issues associated with studying standing in individuals with paraplegia. We used the IPSA to evaluate the ability of proportionalderivative and proportional-integral-derivative (PD and PID, respectively) controllers to regulate quiet standing in an individual with a T3-T4 complete (AIS A) spinal cord injury (SCI). The controllers were able to regulate balance of the inverted pendulum. However, while the controller gains and FES stimulation parameters were chosen based on simulations and experimental calibration, they did not prove adequate to compensate for the day-to-day variability in the subject's muscle strength, creating the need for adjustments prior to every trial. Although the controller output exhibited a saturated phasic profile, we conjecture that increasing the ankle stiffness (by changing the subject's position from sitting to standing) may help to achieve a more physiologically realistic tonic profile.},
keywords = {Algorithms - non invasive 2, Controls, Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
The restoration of arm-free standing in individuals with paraplegia can be accomplished with the help of functional electrical stimulation (FES). An experimental device, the Inverted Pendulum Standing Apparatus (IPSA), is used to study closed-loop FES control of the ankle joint. The IPSA uses the ankle muscles of a sitting subject to balance an inverted pendulum that mimics the subject's body during quiet stance, thereby overcoming the safety issues associated with studying standing in individuals with paraplegia. We used the IPSA to evaluate the ability of proportionalderivative and proportional-integral-derivative (PD and PID, respectively) controllers to regulate quiet standing in an individual with a T3-T4 complete (AIS A) spinal cord injury (SCI). The controllers were able to regulate balance of the inverted pendulum. However, while the controller gains and FES stimulation parameters were chosen based on simulations and experimental calibration, they did not prove adequate to compensate for the day-to-day variability in the subject's muscle strength, creating the need for adjustments prior to every trial. Although the controller output exhibited a saturated phasic profile, we conjecture that increasing the ankle stiffness (by changing the subject's position from sitting to standing) may help to achieve a more physiologically realistic tonic profile.