2005
Kuhn, A; Keller, T
A 3D transient model for transcutaneous functional electrical stimulation Inproceedings
In: Sawan, M (Ed.): pp. 117, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_117,
title = {A 3D transient model for transcutaneous functional electrical stimulation},
author = {A Kuhn and T Keller},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_117_Kuhn.pdf},
year = {2005},
date = {2005-07-01},
pages = {117},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Knowing the 3D current and potential distribution is important for more precise stimulation in transcutaneous functional electrical stimulation. Currently static models can describe the effect of an amplitude change of the stimulation, but the result is the same for different pulse durations. We have developed a transient quasistatic finite element (FE) model that simulates the potential distribution inside the skin, fat, muscle and bone layers of the upper arm. The different tissues are defined by their conductive and dielectric properties. The inclusion of the dielectric properties accounts for capacitive effects in the different tissue layers. This factor has been neglected in earlier studies where only static simulations using the Poisson equation were performed. Our simulation results compared well to external and intramuscular voltage measurements that were performed on three human volunteers. The experimental results showed that the dielectric properties of the skin have to be included in simulations whereas the dielectric properties of the muscle might be neglected.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
Knowing the 3D current and potential distribution is important for more precise stimulation in transcutaneous functional electrical stimulation. Currently static models can describe the effect of an amplitude change of the stimulation, but the result is the same for different pulse durations. We have developed a transient quasistatic finite element (FE) model that simulates the potential distribution inside the skin, fat, muscle and bone layers of the upper arm. The different tissues are defined by their conductive and dielectric properties. The inclusion of the dielectric properties accounts for capacitive effects in the different tissue layers. This factor has been neglected in earlier studies where only static simulations using the Poisson equation were performed. Our simulation results compared well to external and intramuscular voltage measurements that were performed on three human volunteers. The experimental results showed that the dielectric properties of the skin have to be included in simulations whereas the dielectric properties of the muscle might be neglected.
Ogura, T; Murakami, T; Seki, K; Handa, Y
Acute effects of sacral surface electrical stimulation to the uterus during menstruation Inproceedings
In: Sawan, M (Ed.): pp. 103, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_103,
title = {Acute effects of sacral surface electrical stimulation to the uterus during menstruation},
author = {T Ogura and T Murakami and K Seki and Y Handa},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_103_Ogura.pdf},
year = {2005},
date = {2005-07-01},
pages = {103},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {The purpose of this study is to describe the acute effects of sacral surface electrical stimulation (ssES) on the uterine activities in the subjects during menstruation. Eight healthy females subjects who have severe pain subjectively during every menstruation participated in this study. Activities of the uterus were examined Morphological and functional changes of the uterus induced by cyclic ssES for 15min were examined through MRI and MR cinematography, respectively. Thickness of the muscle layer of the uterus decreased significantly after ssES. Power spectrum analysis of the MR cinematography showed a marked decrease in peak power and frequency after ssES treatment. It seems likely that ssES causes an inhibition of the pelvic nerve and/or a facilitation of the hypogastric nerve via electrically induced afferent volleys of the pudendal nerve, and thus, resulted in reduction of the uterine peristaltic movement.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
The purpose of this study is to describe the acute effects of sacral surface electrical stimulation (ssES) on the uterine activities in the subjects during menstruation. Eight healthy females subjects who have severe pain subjectively during every menstruation participated in this study. Activities of the uterus were examined Morphological and functional changes of the uterus induced by cyclic ssES for 15min were examined through MRI and MR cinematography, respectively. Thickness of the muscle layer of the uterus decreased significantly after ssES. Power spectrum analysis of the MR cinematography showed a marked decrease in peak power and frequency after ssES treatment. It seems likely that ssES causes an inhibition of the pelvic nerve and/or a facilitation of the hypogastric nerve via electrically induced afferent volleys of the pudendal nerve, and thus, resulted in reduction of the uterine peristaltic movement.
DeBalthasar, C; Cosendai, G; Hansen, M; Canfield, D; Chu, L; Davis, R; Schulman, J
Attachment of leads to RF-BION(R) microstimulators Inproceedings
In: Sawan, M (Ed.): pp. 128, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_128,
title = {Attachment of leads to RF-BION(R) microstimulators},
author = {C DeBalthasar and G Cosendai and M Hansen and D Canfield and L Chu and R Davis and J Schulman},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_128_DeBalthasar.pdf},
year = {2005},
date = {2005-07-01},
pages = {128},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {The RF-BION (RFB) is a Radio-Frequency (RF) microstimulator powered and controlled by an AC magnetic field which is intended to be used for electrical stimulation applications. It is housed in a cylindrical ceramic case with the stimulating and indifferent electrodes on opposite ends. Due to its small size (16.7 mm, 2.4 mm) and cylindrical shape, it can be easily injected with insertion tools next to a muscle motor-point or close to a nerve to deliver stimulation. For some clinical applications, however, intramuscular lead electrodes or cuff electrodes may be better suited at the stimulation site. To combine the advantages of RFB devices and electrode leads, a leaded RFB has been developed. The leaded RFB is a standard RFB whose simulating end has been modified to allow connection of a variety of electrodes with leads. The leaded RFB has been successfully implanted in an animal for a chronic experiment where it was attached (1) to a Peterson Intramuscular electrode and (2) to a modified Peterson electrode with the distal 3.2 cm of length exposed.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
The RF-BION (RFB) is a Radio-Frequency (RF) microstimulator powered and controlled by an AC magnetic field which is intended to be used for electrical stimulation applications. It is housed in a cylindrical ceramic case with the stimulating and indifferent electrodes on opposite ends. Due to its small size (16.7 mm, 2.4 mm) and cylindrical shape, it can be easily injected with insertion tools next to a muscle motor-point or close to a nerve to deliver stimulation. For some clinical applications, however, intramuscular lead electrodes or cuff electrodes may be better suited at the stimulation site. To combine the advantages of RFB devices and electrode leads, a leaded RFB has been developed. The leaded RFB is a standard RFB whose simulating end has been modified to allow connection of a variety of electrodes with leads. The leaded RFB has been successfully implanted in an animal for a chronic experiment where it was attached (1) to a Peterson Intramuscular electrode and (2) to a modified Peterson electrode with the distal 3.2 cm of length exposed.
Troyk, P R; Cogan, S; DeMichele, G A
Compliance supply-limited driving of iridium oxide (AIROF) electrodes for maintenance in a safe operating region Inproceedings
In: Sawan, M (Ed.): pp. 116, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_116,
title = {Compliance supply-limited driving of iridium oxide (AIROF) electrodes for maintenance in a safe operating region},
author = {P R Troyk and S Cogan and G A DeMichele},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_116_Troyk.pdf},
year = {2005},
date = {2005-07-01},
pages = {116},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Although neural stimulating electrodes that use an activated iridium oxide film coating have existed for more than 20 years, the design of electronic circuits to preserve the electrode electrochemical integrity has received only minimal attention. In contemplating the implantation, in humans, of perhaps hundreds of electrodes for use in visual prostheses, it is essential that methods be defined for driving of the electrodes so that deterioration of the AIROF does not occur. We have developed a simple driving technique that limits the cathodic and anodic voltage excursions of any stimulating electrode within the "water window."},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
Although neural stimulating electrodes that use an activated iridium oxide film coating have existed for more than 20 years, the design of electronic circuits to preserve the electrode electrochemical integrity has received only minimal attention. In contemplating the implantation, in humans, of perhaps hundreds of electrodes for use in visual prostheses, it is essential that methods be defined for driving of the electrodes so that deterioration of the AIROF does not occur. We have developed a simple driving technique that limits the cathodic and anodic voltage excursions of any stimulating electrode within the "water window."
Schuettler, M; Doerge, T; Wien, S L; Becker, S; Staiger, A; Hanauer, M; Kammer, S; Stieglitz, T
Cytotoxicity of Platinum Black Inproceedings
In: Sawan, M (Ed.): pp. 104, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_104,
title = {Cytotoxicity of Platinum Black},
author = {M Schuettler and T Doerge and S L Wien and S Becker and A Staiger and M Hanauer and S Kammer and T Stieglitz},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_104_Schuettler.pdf},
year = {2005},
date = {2005-07-01},
pages = {104},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Platinum black is a coating material for neural electrodes which has the potential to lower the phase-boundary impedance of the electrode-tissue interface dramatically. Depo-siting platinum black by means of electro-plating involves the use of the toxic heavy metal lead as an electrolyte ingredient. Using surface analytical methods, we could not exclude the possibility that traces of lead were integrated into the actual coating. Cytotoxicity tests showed that one of two tested cell lines were affected when exposed to a platinum black extract: The DNA synthesis was disturbed for one fifth of all exposed OLN-93 rat oligodendrocytes. The metabolism of the cells was not affected. However, mouse fibroblasts L-929 did not show any adverse reaction to platinum black. As a conclusion we recommend the use of platinum black as electrode coating for most animal experiments but not for chronic human implants.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
Platinum black is a coating material for neural electrodes which has the potential to lower the phase-boundary impedance of the electrode-tissue interface dramatically. Depo-siting platinum black by means of electro-plating involves the use of the toxic heavy metal lead as an electrolyte ingredient. Using surface analytical methods, we could not exclude the possibility that traces of lead were integrated into the actual coating. Cytotoxicity tests showed that one of two tested cell lines were affected when exposed to a platinum black extract: The DNA synthesis was disturbed for one fifth of all exposed OLN-93 rat oligodendrocytes. The metabolism of the cells was not affected. However, mouse fibroblasts L-929 did not show any adverse reaction to platinum black. As a conclusion we recommend the use of platinum black as electrode coating for most animal experiments but not for chronic human implants.
Ananth, R S
Design of an ultra low-frequency, DC-blocked, implantable electromyogram and cortical sensing amplifier Inproceedings
In: Sawan, M (Ed.): pp. 118, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_118,
title = {Design of an ultra low-frequency, DC-blocked, implantable electromyogram and cortical sensing amplifier},
author = {R S Ananth},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_118_Ananth.pdf},
year = {2005},
date = {2005-07-01},
pages = {118},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {This paper describes the design of an ultra low-frequency, dc-blocked, differential low-noise amplifier (LNA) used for electromyogram and cortical signal detection in an implantable FES or neural prosthetic device. The LNA detects bioelectric signals in the frequency range of 0.035 Hz to 5000 Hz and amplitude range of 10 uV to 100 mV. Large dc voltages of up to 14V can exist across the two sensing electrodes when used for stimulation, requiring the LNA to be dc-blocked. A pair of 50 pF dc-blocking capacitors, PFET inputs and a positive feedback mechanism to cancel the parasitic capacitance of the large input PFETs ensure that the low '1/f'noise traits of the LNA are maintained and ultra low-frequency high-pass response is achieved. The LNA, designed and fabricated in a 0.5um CMOS process, occupies an area of 0.36 mm2, most of which is due to the two 50 pF capacitors. It operates at 2.7V and draws 2.7uA, providing programmable differential gains between 4 and 120, a maximum bandwidth of 0.035 Hz to 5kHz and an input referred noise voltage of 5.6 uVrms in the frequency range of 10 Hz to 5 kHz.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
This paper describes the design of an ultra low-frequency, dc-blocked, differential low-noise amplifier (LNA) used for electromyogram and cortical signal detection in an implantable FES or neural prosthetic device. The LNA detects bioelectric signals in the frequency range of 0.035 Hz to 5000 Hz and amplitude range of 10 uV to 100 mV. Large dc voltages of up to 14V can exist across the two sensing electrodes when used for stimulation, requiring the LNA to be dc-blocked. A pair of 50 pF dc-blocking capacitors, PFET inputs and a positive feedback mechanism to cancel the parasitic capacitance of the large input PFETs ensure that the low '1/f'noise traits of the LNA are maintained and ultra low-frequency high-pass response is achieved. The LNA, designed and fabricated in a 0.5um CMOS process, occupies an area of 0.36 mm2, most of which is due to the two 50 pF capacitors. It operates at 2.7V and draws 2.7uA, providing programmable differential gains between 4 and 120, a maximum bandwidth of 0.035 Hz to 5kHz and an input referred noise voltage of 5.6 uVrms in the frequency range of 10 Hz to 5 kHz.
Kesar, T; Chou, L W; Binder-Macleod, S A
Effects Of Frequency And Intensity On Skeletal Muscle Fatigue During Repetitive Electrical Stimulation Inproceedings
In: Sawan, M (Ed.): pp. 127, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_127,
title = {Effects Of Frequency And Intensity On Skeletal Muscle Fatigue During Repetitive Electrical Stimulation},
author = {T Kesar and L W Chou and S A Binder-Macleod},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_127_Kesar.pdf},
year = {2005},
date = {2005-07-01},
pages = {127},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Both stimulation intensity and frequency can be modulated to compensate for any decline in force generating ability of the muscle due to fatigue during functional electrical stimulation (FES). However, most current FES systems only vary the intensity to control muscle force. This study compared the fatigue produced during repetitive stimulation using 5 different protocols. Three of the 5 protocols consisted of stimulation with trains of a constant frequency and pulse duration (PD) throughout the protocol (no-modulation protocols). The 3 no-modulation protocols used 3 different combinations of frequency and PD: (1) low-frequency, long-PD, (2) medium-frequency, medium-PD, and (3) high-frequency, short-PD. Two of the 5 protocols involved a stepwise increase of either frequency (frequency-modulation) or PD (PD-modulation). All 5 fatigue protocols were made to produce the same initial peak force by varying either the frequency or the PD. The dependant variable was the percent decline in force during each fatigue protocol. The results showed that frequency-modulation produced the least decline in force, followed by PD-modulation. Also, the no-modulation protocol consisting of trains of relatively high-frequency and short-PD produced the greatest decline in force. Although frequency-modulation is not commonly used during clinical FES, it appears that clinicians should consider this strategy to optimize muscle performance.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
Both stimulation intensity and frequency can be modulated to compensate for any decline in force generating ability of the muscle due to fatigue during functional electrical stimulation (FES). However, most current FES systems only vary the intensity to control muscle force. This study compared the fatigue produced during repetitive stimulation using 5 different protocols. Three of the 5 protocols consisted of stimulation with trains of a constant frequency and pulse duration (PD) throughout the protocol (no-modulation protocols). The 3 no-modulation protocols used 3 different combinations of frequency and PD: (1) low-frequency, long-PD, (2) medium-frequency, medium-PD, and (3) high-frequency, short-PD. Two of the 5 protocols involved a stepwise increase of either frequency (frequency-modulation) or PD (PD-modulation). All 5 fatigue protocols were made to produce the same initial peak force by varying either the frequency or the PD. The dependant variable was the percent decline in force during each fatigue protocol. The results showed that frequency-modulation produced the least decline in force, followed by PD-modulation. Also, the no-modulation protocol consisting of trains of relatively high-frequency and short-PD produced the greatest decline in force. Although frequency-modulation is not commonly used during clinical FES, it appears that clinicians should consider this strategy to optimize muscle performance.
Thrasher, T A; Keller, T; Lawrence, M; Popovic, M R
Effects of isometric FES and dynamic FES on cardiovascular parameters on an active tilt-table stepper Inproceedings
In: Sawan, M (Ed.): pp. 125, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_125,
title = {Effects of isometric FES and dynamic FES on cardiovascular parameters on an active tilt-table stepper},
author = {T A Thrasher and T Keller and M Lawrence and M R Popovic},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_125_Thrasher.pdf},
year = {2005},
date = {2005-07-01},
pages = {125},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Functional Electrical Stimulation (FES) has the potential to address orthostatic hypotension, which is a common problem in acute Spinal Cord Injury, by activating the skeletal muscle pump in the lower extremities. A randomized cross-over study was performed in which two interventions were compared: isometric FES and dynamic FES combined with constrained stepping movements. 16 young, able-bodied subjects participated. Each subject performed three trials on separate days in random order. Subjects were tilted to 75 degrees from horizontal for a maximum of 30 minutes. The protocol for the three trials were: A) subjects were immobilized and received no FES; B) subjects were immobilized and cyclical FES was applied; C) subjects'legs were moved in a stepping pattern and FES was applied. Of the 16 subjects, 5 experienced syncope or pre-syncope during the control trial (A). Those 5 plus one more experienced syncope or pre-syncope during the static FES trials (B), however it occurred on average 6.5 minutes later than in the static trials. No one experienced syncope or pre-syncope during the FES-stepping trials (C). Isometric FES appeared to cause short-term increases in blood pressure and heart rate, but these were not maintained over the long term. Dynamic FES produced much better results. We conclude that FES has potential to counteract orthostatic stress, however it should be combined with movement of the legs.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
Functional Electrical Stimulation (FES) has the potential to address orthostatic hypotension, which is a common problem in acute Spinal Cord Injury, by activating the skeletal muscle pump in the lower extremities. A randomized cross-over study was performed in which two interventions were compared: isometric FES and dynamic FES combined with constrained stepping movements. 16 young, able-bodied subjects participated. Each subject performed three trials on separate days in random order. Subjects were tilted to 75 degrees from horizontal for a maximum of 30 minutes. The protocol for the three trials were: A) subjects were immobilized and received no FES; B) subjects were immobilized and cyclical FES was applied; C) subjects'legs were moved in a stepping pattern and FES was applied. Of the 16 subjects, 5 experienced syncope or pre-syncope during the control trial (A). Those 5 plus one more experienced syncope or pre-syncope during the static FES trials (B), however it occurred on average 6.5 minutes later than in the static trials. No one experienced syncope or pre-syncope during the FES-stepping trials (C). Isometric FES appeared to cause short-term increases in blood pressure and heart rate, but these were not maintained over the long term. Dynamic FES produced much better results. We conclude that FES has potential to counteract orthostatic stress, however it should be combined with movement of the legs.
Song, T; Hwang, S H; Hyun, B R; Khang, G; Lee, M S; Lee, B S
Effects of Pulse Waveforms and Muscle Lengths on Muscle Force and Fatigue Resistance Inproceedings
In: Sawan, M (Ed.): pp. 106, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_106,
title = {Effects of Pulse Waveforms and Muscle Lengths on Muscle Force and Fatigue Resistance},
author = {T Song and S H Hwang and B R Hyun and G Khang and M S Lee and B S Lee},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_106_Song.pdf},
year = {2005},
date = {2005-07-01},
pages = {106},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {We investigated contractile properties, force-generating capability and fatigue resistance, of quadriceps of 6 paraplegic patients and 7 healthy subjects. The knee extensor torque was monitored for more than 30 seconds during each stimulation session where 4 different waveforms were applied at 3 different knee angles for the patients. The result suggested that monophasic pulses could generate a higher torque with higher fatigue resistance than biphasic pulses at the cost of risks like skin irritation, when the muscle was submaximally stimulated. Also, the knee extensor showed the highest fatigue resistance at the optimal length when it was stimulated as well as voluntarily activated. More experiments are being conducted, however, to confirm this observation.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
We investigated contractile properties, force-generating capability and fatigue resistance, of quadriceps of 6 paraplegic patients and 7 healthy subjects. The knee extensor torque was monitored for more than 30 seconds during each stimulation session where 4 different waveforms were applied at 3 different knee angles for the patients. The result suggested that monophasic pulses could generate a higher torque with higher fatigue resistance than biphasic pulses at the cost of risks like skin irritation, when the muscle was submaximally stimulated. Also, the knee extensor showed the highest fatigue resistance at the optimal length when it was stimulated as well as voluntarily activated. More experiments are being conducted, however, to confirm this observation.
Kim, S J; Roy, R R; Zhong, H; Ambartsumyan, L; Baldwin, K M; Edgerton, V R
Efficacy of functional electrical stimulation in ameliorating inactivity-induced atrophy Inproceedings
In: Sawan, M (Ed.): pp. 113, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_113,
title = {Efficacy of functional electrical stimulation in ameliorating inactivity-induced atrophy},
author = {S J Kim and R R Roy and H Zhong and L Ambartsumyan and K M Baldwin and V R Edgerton},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_113_Kim.pdf},
year = {2005},
date = {2005-07-01},
pages = {113},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {The amount and pattern of electromechanical activity, i.e., activation and loading, are important determinants in the homeostatic regulation of skeletal muscle. The purpose of this study was to examine the effects of inactivity on muscle atrophy, and to determine the optimum electromechanical stimulation paradigm for maintaining muscle mass using a wireless implantable microstimulator (BION Microstimulator). The model of spinal cord isolation (SI) was used to create a baseline of near zero activity to which known amounts and patterns of activation could be imposed. Beginning 2 days after SI surgery, the BION implanted leg received daily electromechanical stimulation to induce isometric contractions. All stimulation protocols resulted in a total of 1 to 4 min of activity in a 24-hr period. After 30 days, the same amount of high-load, short-duration stimulation delivered in two vs. one bout per day was more efficacious in ameliorating muscle atrophy (72 and 79% of control, respectively). At a shorter training duration (5 days), the frequency, number, and intensity of stimulation were adjusted to produce an optimum paradigm, one that preserved 99% of the relative muscle mass. These results indicate that as little as 1 to 4 min of patterned high-load isometric contractions per day in an otherwise inactive muscle can preserve a normal homeostatic state and thus prevent muscle atrophy, and that distributing the same amount of activity in two sessions/day was more effective than in one session/day.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
The amount and pattern of electromechanical activity, i.e., activation and loading, are important determinants in the homeostatic regulation of skeletal muscle. The purpose of this study was to examine the effects of inactivity on muscle atrophy, and to determine the optimum electromechanical stimulation paradigm for maintaining muscle mass using a wireless implantable microstimulator (BION Microstimulator). The model of spinal cord isolation (SI) was used to create a baseline of near zero activity to which known amounts and patterns of activation could be imposed. Beginning 2 days after SI surgery, the BION implanted leg received daily electromechanical stimulation to induce isometric contractions. All stimulation protocols resulted in a total of 1 to 4 min of activity in a 24-hr period. After 30 days, the same amount of high-load, short-duration stimulation delivered in two vs. one bout per day was more efficacious in ameliorating muscle atrophy (72 and 79% of control, respectively). At a shorter training duration (5 days), the frequency, number, and intensity of stimulation were adjusted to produce an optimum paradigm, one that preserved 99% of the relative muscle mass. These results indicate that as little as 1 to 4 min of patterned high-load isometric contractions per day in an otherwise inactive muscle can preserve a normal homeostatic state and thus prevent muscle atrophy, and that distributing the same amount of activity in two sessions/day was more effective than in one session/day.
Bernard, S; Techer, J D; Cathebras, G; Bertrand, Y; Guiraud, D
Electrical Performances of a New Multipolar Micro-Stimulator Inproceedings
In: Sawan, M (Ed.): pp. 107, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_107,
title = {Electrical Performances of a New Multipolar Micro-Stimulator},
author = {S Bernard and J D Techer and G Cathebras and Y Bertrand and D Guiraud},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_107_Bernard.pdf},
year = {2005},
date = {2005-07-01},
pages = {107},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {A large number of applications exist for Multipolar stimulation. But the main difficulty for this kind of stimulation is the stimulator which has to be able to generate accurate stimulation current and to share this current between the different cathodes. In this paper we propose an electrical evaluation of the micro-stimulator we have developed. To do this, we have conducted several experiments on physiological solution to evaluate the linearity and the sharing stability of the generated current according to a large range of stimulation current. We obtain a linearity error lower than 2% for the full range of conversion. Moreover, our micro-stimulator is useable for multipolar stimulation with a constant ratio between current in each cathode with an error lower than 3%.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
A large number of applications exist for Multipolar stimulation. But the main difficulty for this kind of stimulation is the stimulator which has to be able to generate accurate stimulation current and to share this current between the different cathodes. In this paper we propose an electrical evaluation of the micro-stimulator we have developed. To do this, we have conducted several experiments on physiological solution to evaluate the linearity and the sharing stability of the generated current according to a large range of stimulation current. We obtain a linearity error lower than 2% for the full range of conversion. Moreover, our micro-stimulator is useable for multipolar stimulation with a constant ratio between current in each cathode with an error lower than 3%.
Laaziri, Y; Mounaim, F; Elzayat, E; Sawan, M; Elhilali, M M
Electrode-tissues interface: Modeling and acute experiments on dogs Inproceedings
In: Sawan, M (Ed.): pp. 111, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_111,
title = {Electrode-tissues interface: Modeling and acute experiments on dogs},
author = {Y Laaziri and F Mounaim and E Elzayat and M Sawan and M M Elhilali},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_111_Laaziri.pdf},
year = {2005},
date = {2005-07-01},
pages = {111},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {In this paper, we propose an empirical model for the Electrode-Tissues Interface (ETI). The model was validated by in vivo impedance measurements of the contact between cuff electrode and sacral nerves (S1-3) in four acute dog experiments for a frequency range of 1 Hz to 100 kHz. The results demonstrate a closer fitting between our proposed model and experimental measurements. Application of such model would allow us to have an accurate estimation of ETI impedance variation during nerve stimulation or Electroneurogram (ENG) recording.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
In this paper, we propose an empirical model for the Electrode-Tissues Interface (ETI). The model was validated by in vivo impedance measurements of the contact between cuff electrode and sacral nerves (S1-3) in four acute dog experiments for a frequency range of 1 Hz to 100 kHz. The results demonstrate a closer fitting between our proposed model and experimental measurements. Application of such model would allow us to have an accurate estimation of ETI impedance variation during nerve stimulation or Electroneurogram (ENG) recording.
Kowalczewski, J; Gritsenko, V; Ashworth, N; Prochazka, A
FES-Assisted Exercise Therapy in the Sub-Acute Phase of Stroke Recovery Inproceedings
In: Sawan, M (Ed.): pp. 101, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_101,
title = {FES-Assisted Exercise Therapy in the Sub-Acute Phase of Stroke Recovery},
author = {J Kowalczewski and V Gritsenko and N Ashworth and A Prochazka},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_101_Kowalczewski.pdf},
year = {2005},
date = {2005-07-01},
pages = {101},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {A surface stimulator combined with an instrumented workstation comprised of tasks of daily life was used to rehabilitate the upper extremity of patients with severe hemiplegia. 20 sub-acute patients (no more than 3 months post stroke) took part in this double blind randomised clinical trial. Ten patients in the experimental group underwent daily 1 hour training sessions on the workstation with functional electrical stimulation for a duration of 4 weeks. The control group of 10 patients received 15 minutes of daily sub threshold stimulation and one training session per week on the workstation. The workstation was used for task-specific training as well as kinematic data recording. Outcome measures of hand function included the Wolf Motor Function Test (WMFT), the Upper extremity Fugl-Myer Test (FMT), the Motor Activity Log (MAL), and the kinematic scores derived from the workstation. The results indicate a significant improvement in hand function for the treatment group over the control group in some but not all of the outcome measures.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
A surface stimulator combined with an instrumented workstation comprised of tasks of daily life was used to rehabilitate the upper extremity of patients with severe hemiplegia. 20 sub-acute patients (no more than 3 months post stroke) took part in this double blind randomised clinical trial. Ten patients in the experimental group underwent daily 1 hour training sessions on the workstation with functional electrical stimulation for a duration of 4 weeks. The control group of 10 patients received 15 minutes of daily sub threshold stimulation and one training session per week on the workstation. The workstation was used for task-specific training as well as kinematic data recording. Outcome measures of hand function included the Wolf Motor Function Test (WMFT), the Upper extremity Fugl-Myer Test (FMT), the Motor Activity Log (MAL), and the kinematic scores derived from the workstation. The results indicate a significant improvement in hand function for the treatment group over the control group in some but not all of the outcome measures.
Jezernik, S; Sinkjaer, T
Finite Element Modeling Validation of Energy-Optimal Electrical Stimulation Waveform Inproceedings
In: Sawan, M (Ed.): pp. 105, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_105,
title = {Finite Element Modeling Validation of Energy-Optimal Electrical Stimulation Waveform},
author = {S Jezernik and T Sinkjaer},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_105_Jezernik.pdf},
year = {2005},
date = {2005-07-01},
pages = {105},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {In this study we have validated our earlier theoretical result that an exponentially rising current stimulation waveform enables excitation of nervous and muscular tissue at lowest possible energy. The validation was performed via 3D FEM (finite element modeling) of an upper limb, surface stimulation electrodes, and a 1D FEM of a nerve fiber located within the upper limb. It can be concluded that the influence of surface stimulation and body inhomogenities produces only a distortion of the amplitude and spatial distribution of the extracellular potential generated by the injected current, however, that an appropriate exponentially rising waveform generates the same spatially localized peak membrane potential as the corresponding rectangular stimulation - but at a substantially lower stimulation energy. At the end of this article we also present an electronic circuit diagram that realizes the energy-optimal stimulation.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
In this study we have validated our earlier theoretical result that an exponentially rising current stimulation waveform enables excitation of nervous and muscular tissue at lowest possible energy. The validation was performed via 3D FEM (finite element modeling) of an upper limb, surface stimulation electrodes, and a 1D FEM of a nerve fiber located within the upper limb. It can be concluded that the influence of surface stimulation and body inhomogenities produces only a distortion of the amplitude and spatial distribution of the extracellular potential generated by the injected current, however, that an appropriate exponentially rising waveform generates the same spatially localized peak membrane potential as the corresponding rectangular stimulation - but at a substantially lower stimulation energy. At the end of this article we also present an electronic circuit diagram that realizes the energy-optimal stimulation.
Klakowicz, P M; Baldwin, E R L; Lagerquist, O; Collins, D F
Increased H-reflexes boost muscle contractions during tetanic stimulation of the tibial nerve in neurologically-intact persons Inproceedings
In: Sawan, M (Ed.): pp. 102, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_102,
title = {Increased H-reflexes boost muscle contractions during tetanic stimulation of the tibial nerve in neurologically-intact persons},
author = {P M Klakowicz and E R L Baldwin and O Lagerquist and D F Collins},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_102_Klakowicz.pdf},
year = {2005},
date = {2005-07-01},
pages = {102},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Tetanic neuromuscular electrical stimulation (at 100 Hz) over ankle dorsiflexors and plantarflexors in persons with and without spinal cord injury can evoke contractions, which are considered spinal of origin, extra to those due to stimulating motor axons directly. Presently, we determined whether H-reflexes contribute to "extra" plantarflexion contractions, evoked in relaxed neurologically-intact persons by stimulating the tibial nerve at just above motor threshold: at 20 Hz for 2 s - 100 Hz (burst) for 2 s - 20 Hz for 3 s (1-ms pulses). Extra contractions were generated if isometric ankle torque was larger after the 100-Hz burst (at 6 s) than before it (at 1 s). The peak-to-peak amplitude of each soleus H-reflex and M-wave was quantified during 20-Hz stimulation, and mean amplitudes were also compared at 1 s and 6 s (average of responses within 400 ms of selected time). Overall (N=6), subsequent to the first H-reflex (~50% Mmax), reflexes were typically depressed during the initial 20-Hz stimulation. From before to after the 100-Hz burst, the mean H-reflex increased from 12 to 21 % Mmax (P<0.05) and the corresponding mean torque increased from 4 to 10 % MVC (P<0.01), while the mean M-wave of 2 % Mmax was unchanged. We conclude that increased spinal reflex responses contribute to the extra plantarflexion. Since motoneurons are reflexively recruited, presumably in a normal physiological order, the implication is that such contractions may be more fatigue resistant than those due to directly stimulating motor axons.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
Tetanic neuromuscular electrical stimulation (at 100 Hz) over ankle dorsiflexors and plantarflexors in persons with and without spinal cord injury can evoke contractions, which are considered spinal of origin, extra to those due to stimulating motor axons directly. Presently, we determined whether H-reflexes contribute to "extra" plantarflexion contractions, evoked in relaxed neurologically-intact persons by stimulating the tibial nerve at just above motor threshold: at 20 Hz for 2 s - 100 Hz (burst) for 2 s - 20 Hz for 3 s (1-ms pulses). Extra contractions were generated if isometric ankle torque was larger after the 100-Hz burst (at 6 s) than before it (at 1 s). The peak-to-peak amplitude of each soleus H-reflex and M-wave was quantified during 20-Hz stimulation, and mean amplitudes were also compared at 1 s and 6 s (average of responses within 400 ms of selected time). Overall (N=6), subsequent to the first H-reflex (~50% Mmax), reflexes were typically depressed during the initial 20-Hz stimulation. From before to after the 100-Hz burst, the mean H-reflex increased from 12 to 21 % Mmax (P<0.05) and the corresponding mean torque increased from 4 to 10 % MVC (P<0.01), while the mean M-wave of 2 % Mmax was unchanged. We conclude that increased spinal reflex responses contribute to the extra plantarflexion. Since motoneurons are reflexively recruited, presumably in a normal physiological order, the implication is that such contractions may be more fatigue resistant than those due to directly stimulating motor axons.
Polasek, K H; Hoyen, H A; Keith, M W; Kirsch, R F; Tyler, D J
Intraoperative Testing of Selectivity of Spiral Nerve Cuff Electrodes Inproceedings
In: Sawan, M (Ed.): pp. 100, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_100,
title = {Intraoperative Testing of Selectivity of Spiral Nerve Cuff Electrodes},
author = {K H Polasek and H A Hoyen and M W Keith and R F Kirsch and D J Tyler},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_100_Polasek.pdf},
year = {2005},
date = {2005-07-01},
pages = {100},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Nerve cuff electrodes were used intraoperatively to stimulate peripheral nerves to examine electrode selectivity in the human upper extremity. Subjects were recruited from patients undergoing upper extremity nerve repair procedures. The nerves were stimulated through four individual contacts located radially around the nerve with varying parameters. Data was recorded to estimate stimulation threshold and determine selectivity. Thresholds appeared to be higher than anticipated based on previous cat data. Preliminary selectivity was demonstrated on several nerves.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
Nerve cuff electrodes were used intraoperatively to stimulate peripheral nerves to examine electrode selectivity in the human upper extremity. Subjects were recruited from patients undergoing upper extremity nerve repair procedures. The nerves were stimulated through four individual contacts located radially around the nerve with varying parameters. Data was recorded to estimate stimulation threshold and determine selectivity. Thresholds appeared to be higher than anticipated based on previous cat data. Preliminary selectivity was demonstrated on several nerves.
Gonzalez, H J N; Ferro, F P; Ferreira, D M; Cliquet, A
Locomotor training in tetraplegic patients: an orthopedic assessment upon its effects on the osteoarticular system Inproceedings
In: Sawan, M (Ed.): pp. 108, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_108,
title = {Locomotor training in tetraplegic patients: an orthopedic assessment upon its effects on the osteoarticular system},
author = {H J N Gonzalez and F P Ferro and D M Ferreira and A Cliquet},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_108_Gonzalez.pdf},
year = {2005},
date = {2005-07-01},
pages = {108},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {This study has been evaluating tetraplegic patients who have been walking for several months with the aid of a system that involves neuromuscular stimulation, treadmill and a harness support device[20-23]. Clinical and radiological evolution of two patients who have taken part in the training programme were assessed. Improvement on the severity of the heterotopical ossification has been noticed in both hip joints of the first patient. On the other patient, despite knee instability and an intense programme routine, no knee injury was observed, suggesting that the training programme is safe for this joint.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
This study has been evaluating tetraplegic patients who have been walking for several months with the aid of a system that involves neuromuscular stimulation, treadmill and a harness support device[20-23]. Clinical and radiological evolution of two patients who have taken part in the training programme were assessed. Improvement on the severity of the heterotopical ossification has been noticed in both hip joints of the first patient. On the other patient, despite knee instability and an intense programme routine, no knee injury was observed, suggesting that the training programme is safe for this joint.
Gosselin, B; Sawan, M
A low power portable multichannel neural data acquisition system Inproceedings
In: Sawan, M (Ed.): pp. 119, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_119,
title = {A low power portable multichannel neural data acquisition system},
author = {B Gosselin and M Sawan},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_119_Gosselin.pdf},
year = {2005},
date = {2005-07-01},
pages = {119},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {We present the design and test of a portable multichannel neural data acquisition system. Each analog channel features a low noise (10nV/oeHz), high CMRR (83.4dB) input stage, a 4th order bandpass filter and a selectable gain (60.8dB - 100.8dB). An automatic DC restoration circuit in the input stage rejects the electrodes DC voltage mismatch. The multichannel analog signals are sampled, digitized at 32ksps and transferred through a USB connection. Testing of the device demonstrates its reliability to process neural signals and to be used as a stand-alone recording unit for in-vivo experiments. The implemented printed circuit board consumes up to only 75mW.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
We present the design and test of a portable multichannel neural data acquisition system. Each analog channel features a low noise (10nV/oeHz), high CMRR (83.4dB) input stage, a 4th order bandpass filter and a selectable gain (60.8dB - 100.8dB). An automatic DC restoration circuit in the input stage rejects the electrodes DC voltage mismatch. The multichannel analog signals are sampled, digitized at 32ksps and transferred through a USB connection. Testing of the device demonstrates its reliability to process neural signals and to be used as a stand-alone recording unit for in-vivo experiments. The implemented printed circuit board consumes up to only 75mW.
Ding, J; Kesar, T; Wexler, A S; Binder-Macleod, S A
A Mathematical Model That Incorporates The Force-Intensity Relationship Of Human Skeletal Muscle Inproceedings
In: Sawan, M (Ed.): pp. 112, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_112,
title = {A Mathematical Model That Incorporates The Force-Intensity Relationship Of Human Skeletal Muscle},
author = {J Ding and T Kesar and A S Wexler and S A Binder-Macleod},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_112_Ding.pdf},
year = {2005},
date = {2005-07-01},
pages = {112},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {We have previously reported the development of a force-model system that accurately predicts the force-frequency relation of human skeletal muscle. The ability to also predict the effects of stimulation intensity on muscle force can enable a more precise prediction of muscle forces and allow a better control of FES-elicited movements. The model presented here incorporates the force-intensity relationship to predict the effects of stimulation intensity and frequency on skeletal muscle forces. The current model was developed and tested on quadriceps femoris muscles (N=7) of healthy subjects. Our model successfully predicted the forces produced when the muscle was activated with stimulation trains of different pulse durations (100 ~ 600 us) and frequencies (12.5Hz ~ 80 Hz). The successful addition of an intensity component to our model system further supports its potential use for the design of subject-specific stimulation patterns for FES applications.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
We have previously reported the development of a force-model system that accurately predicts the force-frequency relation of human skeletal muscle. The ability to also predict the effects of stimulation intensity on muscle force can enable a more precise prediction of muscle forces and allow a better control of FES-elicited movements. The model presented here incorporates the force-intensity relationship to predict the effects of stimulation intensity and frequency on skeletal muscle forces. The current model was developed and tested on quadriceps femoris muscles (N=7) of healthy subjects. Our model successfully predicted the forces produced when the muscle was activated with stimulation trains of different pulse durations (100 ~ 600 us) and frequencies (12.5Hz ~ 80 Hz). The successful addition of an intensity component to our model system further supports its potential use for the design of subject-specific stimulation patterns for FES applications.
Stieglitz, T
Methods to Determine the Stability of Polymer Encapsulations Inproceedings
In: Sawan, M (Ed.): pp. 110, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_110,
title = {Methods to Determine the Stability of Polymer Encapsulations},
author = {T Stieglitz},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_110_Stieglitz.pdf},
year = {2005},
date = {2005-07-01},
pages = {110},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Biomedical Microsystems that are designated to be implanted in the human body as neural prostheses have to fulfill strict requirements regarding their biostability. Applications like retina implants that have to be flexible and transparent, at least if parts are integrated into an artificial intraocular lens. In these cases, metal or ceramic housings to protect electronic circuitry cannot be used. Therefore, polymer layers were proposed as long-term stable encapsulation. However, no microimplant without hermetic packaging (glass, metal, ceramics) has been transferred into clinical practice yet. Potential candidates for flexible polymer-based substrates, insulation, and encapsulation layers for microimplants are polyimide, parylene C and silicone rubbers. The development of test structures for electrical measurements to investigate the insulation resistance of the encapsulation itself and the impedance of the encapsulation-substrate compound will be evaluated under accelerated testing paradigms to estimate the mean time to failure. Optical measurements (Fourier transformed infrared spectroscopy-FTIR) accompany electrical measurements under in vitro conditions to correlate structural material changes to variations in insulation resistance.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
Biomedical Microsystems that are designated to be implanted in the human body as neural prostheses have to fulfill strict requirements regarding their biostability. Applications like retina implants that have to be flexible and transparent, at least if parts are integrated into an artificial intraocular lens. In these cases, metal or ceramic housings to protect electronic circuitry cannot be used. Therefore, polymer layers were proposed as long-term stable encapsulation. However, no microimplant without hermetic packaging (glass, metal, ceramics) has been transferred into clinical practice yet. Potential candidates for flexible polymer-based substrates, insulation, and encapsulation layers for microimplants are polyimide, parylene C and silicone rubbers. The development of test structures for electrical measurements to investigate the insulation resistance of the encapsulation itself and the impedance of the encapsulation-substrate compound will be evaluated under accelerated testing paradigms to estimate the mean time to failure. Optical measurements (Fourier transformed infrared spectroscopy-FTIR) accompany electrical measurements under in vitro conditions to correlate structural material changes to variations in insulation resistance.
Ishikawa, Y; Shimada, Y; Iwami, T; Kamada, K; Matsunaga, T; Misawa, A; Aizawa, T; Itoi, E
Model simulation for restoration of trunk in complete paraplegia by functional electrical stimulation Inproceedings
In: Sawan, M (Ed.): pp. 123, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_123,
title = {Model simulation for restoration of trunk in complete paraplegia by functional electrical stimulation},
author = {Y Ishikawa and Y Shimada and T Iwami and K Kamada and T Matsunaga and A Misawa and T Aizawa and E Itoi},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_123_Ishikawa.pdf},
year = {2005},
date = {2005-07-01},
pages = {123},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Purpose: To design a musculo-skeletal dynamic spine model with which we can perform FES effectively as well as the simulation of spinal motion and analysis of stress distribution to the vertebra. Method: The skeletal model was designed from computed tomography (CT) data of a young male healthy volunteer. The muscles, discs and ligaments were attached to the skeletal model correctly as possible as we could. Physical properties of the muscles, discs and ligaments, which could be used to design this model, were mainly obtained from past literatures. The simulation of dynamic spinal motion and analysis of vertebral von Mises stress were performed simultaneously by means of using 3D analysis software "Visual Nastran 4D". Result: The spinal dynamic motion and vertebral stress distribution were observed from our spinal model. Conclusion: We designed the musculo-skeletal spine model that would be useful for the simulation of dynamic motion and analysis of stress distribution with a role of FES to the trunk extensor muscles.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
Purpose: To design a musculo-skeletal dynamic spine model with which we can perform FES effectively as well as the simulation of spinal motion and analysis of stress distribution to the vertebra. Method: The skeletal model was designed from computed tomography (CT) data of a young male healthy volunteer. The muscles, discs and ligaments were attached to the skeletal model correctly as possible as we could. Physical properties of the muscles, discs and ligaments, which could be used to design this model, were mainly obtained from past literatures. The simulation of dynamic spinal motion and analysis of vertebral von Mises stress were performed simultaneously by means of using 3D analysis software "Visual Nastran 4D". Result: The spinal dynamic motion and vertebral stress distribution were observed from our spinal model. Conclusion: We designed the musculo-skeletal spine model that would be useful for the simulation of dynamic motion and analysis of stress distribution with a role of FES to the trunk extensor muscles.
Sehil, M; Sawan, M; Khouas, A
Modeling Efficient Inductive Power Transfer Required To Supply Implantable Devices Inproceedings
In: Sawan, M (Ed.): pp. 115, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_115,
title = {Modeling Efficient Inductive Power Transfer Required To Supply Implantable Devices},
author = {M Sehil and M Sawan and A Khouas},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_115_Sehil.pdf},
year = {2005},
date = {2005-07-01},
pages = {115},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {This paper presents a model for inductively coupled links with an integrated receiver on silicon. To be accurate, this model includes losses related to the integration of the receiver. The modelling technique of the receiver coil has been verified using Agilent Momentum Electro-Magnetic simulations. This compre-hensive model is employed to obtain maximum power efficiency by performing a discrete optimization of the geometric dimensions of the link coils. The optimized link can deliver 50mW to a visual cortical stimulator and monitoring devices with an efficiency of 21% at a distance of 1cm. The receiver has 4mm of diameter.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
This paper presents a model for inductively coupled links with an integrated receiver on silicon. To be accurate, this model includes losses related to the integration of the receiver. The modelling technique of the receiver coil has been verified using Agilent Momentum Electro-Magnetic simulations. This compre-hensive model is employed to obtain maximum power efficiency by performing a discrete optimization of the geometric dimensions of the link coils. The optimized link can deliver 50mW to a visual cortical stimulator and monitoring devices with an efficiency of 21% at a distance of 1cm. The receiver has 4mm of diameter.
P.Ferron, D; Sawan, M
Modeling Peripheral Nerve to improve Selective Stimulation Inproceedings
In: Sawan, M (Ed.): pp. 114, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_114,
title = {Modeling Peripheral Nerve to improve Selective Stimulation},
author = {D P.Ferron and M Sawan},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_114_P.Ferron.pdf},
year = {2005},
date = {2005-07-01},
pages = {114},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {We present in this paper the model of a whole nerve bundle constructed under Neuron software. This model is being used to reproduce any internal physical configuration of a nerve bundle from the peripheral system and it allows building any other type of nerves. Simulation results prove the validity of the model and allow to confirm the feasibility of performing selective activation of fibers depending on frequency variability.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
We present in this paper the model of a whole nerve bundle constructed under Neuron software. This model is being used to reproduce any internal physical configuration of a nerve bundle from the peripheral system and it allows building any other type of nerves. Simulation results prove the validity of the model and allow to confirm the feasibility of performing selective activation of fibers depending on frequency variability.
Caparso, A V; Mansour, J M; Durand, D M
A nerve cuff electrode for controlled reshaping of nerve geometry Inproceedings
In: Sawan, M (Ed.): pp. 124, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_124,
title = {A nerve cuff electrode for controlled reshaping of nerve geometry},
author = {A V Caparso and J M Mansour and D M Durand},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_124_Caparso.pdf},
year = {2005},
date = {2005-07-01},
pages = {124},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {The Flat Interface Nerve Electrode (FINE) can reshape the nerve into an elongated oval and provide selective stimulation. The rate of closure of this electrode is difficult to control. The Slowly Closing - FINE (SC-FINE) has been designed to provide an opening height larger than the size of the nerve to accommodate initial swelling an to close at a controllable rate. The design is created by combining the reshaping properties of the FINE and the controllable degradation of Poly (DL lactic-co-glycolic) acid (PLGA). Bonding 50/50 or 65/35 PLGA to a stretched FINE increased the opening heights (OH) on average from 0.1 mm to 1.66 textpm 0.45 and 2.05 textpm 0.55 mm respectively. A computer model was generated to guide the design of this electrode. The addition of the PLGA films controls the time course of closure over a period of 16 textpm 1 days and 14 to 16 hours for the 50/50 and 65/35 SC-FINEs respectively in vitro.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
The Flat Interface Nerve Electrode (FINE) can reshape the nerve into an elongated oval and provide selective stimulation. The rate of closure of this electrode is difficult to control. The Slowly Closing - FINE (SC-FINE) has been designed to provide an opening height larger than the size of the nerve to accommodate initial swelling an to close at a controllable rate. The design is created by combining the reshaping properties of the FINE and the controllable degradation of Poly (DL lactic-co-glycolic) acid (PLGA). Bonding 50/50 or 65/35 PLGA to a stretched FINE increased the opening heights (OH) on average from 0.1 mm to 1.66 textpm 0.45 and 2.05 textpm 0.55 mm respectively. A computer model was generated to guide the design of this electrode. The addition of the PLGA films controls the time course of closure over a period of 16 textpm 1 days and 14 to 16 hours for the 50/50 and 65/35 SC-FINEs respectively in vitro.
Feili, D; Schuettler, M; Koch, K P; Stieglitz, T; Hoffmann, K P
Organic Field Effect Transistors for Neural Stimulation - In Vitro Tests Inproceedings
In: Sawan, M (Ed.): pp. 121, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_121,
title = {Organic Field Effect Transistors for Neural Stimulation - In Vitro Tests},
author = {D Feili and M Schuettler and K P Koch and T Stieglitz and K P Hoffmann},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_121_Feili.pdf},
year = {2005},
date = {2005-07-01},
pages = {121},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Pentacene is an organic semiconductor material, which can be integrated in micromachined polyimide-based high channel neural stimulation electrode arrays in order to build active switching matrices. Different to conventional direct one-to-one wiring between electrode contacts and stimulator output stages, a matrix of n x m electrode contacts requires only n + m interconnects to a stimulator, when active switching elements are used. In this paper, we demonstrate that Pentacene transistors can be used as switching elements and are capable of driving currents suitable for electrical stimulation of nervous tissue.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
Pentacene is an organic semiconductor material, which can be integrated in micromachined polyimide-based high channel neural stimulation electrode arrays in order to build active switching matrices. Different to conventional direct one-to-one wiring between electrode contacts and stimulator output stages, a matrix of n x m electrode contacts requires only n + m interconnects to a stimulator, when active switching elements are used. In this paper, we demonstrate that Pentacene transistors can be used as switching elements and are capable of driving currents suitable for electrical stimulation of nervous tissue.
Feili, D; Schuettler, M; Koch, K P; Stieglitz, T; Hoffmann, K P
Organic Field Effect Transistors for Neural Stimulation - In Vitro Tests Inproceedings
In: Sawan, M (Ed.): pp. 120, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_120,
title = {Organic Field Effect Transistors for Neural Stimulation - In Vitro Tests},
author = {D Feili and M Schuettler and K P Koch and T Stieglitz and K P Hoffmann},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_120_Feili.pdf},
year = {2005},
date = {2005-07-01},
pages = {120},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Pentacene is an organic semiconductor that has the potential to be used as a switching element in active electrode matrices for neural stimulation. In this paper, we demonstrated that Pentacene-based organic field effect transistors (OFETs) can be used to drive stimulation currents of sufficient amplitude through neural electrodes in physiological-like environment. Furthermore, Pentacene was verified in respect to potential affects on cell vitality. The results of these tests indicate that extracts from Pentacene neither inhibit proliferation nor metabolism of the tested mouse fibroblasts. However, some effect on the cell vitality was observed, when cells were in direct contact to Pentacene for 48 h.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
Pentacene is an organic semiconductor that has the potential to be used as a switching element in active electrode matrices for neural stimulation. In this paper, we demonstrated that Pentacene-based organic field effect transistors (OFETs) can be used to drive stimulation currents of sufficient amplitude through neural electrodes in physiological-like environment. Furthermore, Pentacene was verified in respect to potential affects on cell vitality. The results of these tests indicate that extracts from Pentacene neither inhibit proliferation nor metabolism of the tested mouse fibroblasts. However, some effect on the cell vitality was observed, when cells were in direct contact to Pentacene for 48 h.
Krueger, T B; Becker, S; Hoffmann, K P; Stieglitz, T
Testing Procedures for Safe Cell Stimulation Parameters with Micro-Electrodes Using Living Cells Inproceedings
In: Sawan, M (Ed.): pp. 109, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_109,
title = {Testing Procedures for Safe Cell Stimulation Parameters with Micro-Electrodes Using Living Cells},
author = {T B Krueger and S Becker and K P Hoffmann and T Stieglitz},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_109_Krueger.pdf},
year = {2005},
date = {2005-07-01},
pages = {109},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Fabricating micro-electrodes with new procedures it is not clear in advance how the characteristics of the designed electrodes will be. To avoid time consuming and possibly unethical procedures in-vivo, we are introducing a combined test method of in-vitro studies and cell-on-a-chip experiments. Electrodes were first characterized in-vitro by impedance spectroscopy, and then tested for long-term stability with stimulation pulses. Cells were cultivated on the electrode design. With confluent cell layers, implying the biocompatibility of the chosen materials, chronic stimulation of the electrodes has been undergone. The electrochemical limit of the maximum charge transfer capacitance of the electrodes was determined. As well as the tolerable stimulus injection limit for avoiding cell damage or even cell death. The results give a clear outlook of the electrode behaviour in the living environment, its later destiny.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
Fabricating micro-electrodes with new procedures it is not clear in advance how the characteristics of the designed electrodes will be. To avoid time consuming and possibly unethical procedures in-vivo, we are introducing a combined test method of in-vitro studies and cell-on-a-chip experiments. Electrodes were first characterized in-vitro by impedance spectroscopy, and then tested for long-term stability with stimulation pulses. Cells were cultivated on the electrode design. With confluent cell layers, implying the biocompatibility of the chosen materials, chronic stimulation of the electrodes has been undergone. The electrochemical limit of the maximum charge transfer capacitance of the electrodes was determined. As well as the tolerable stimulus injection limit for avoiding cell damage or even cell death. The results give a clear outlook of the electrode behaviour in the living environment, its later destiny.
Lawrence, M; Keller, T A
Transcutaneous Electrode Measurement System Inproceedings
In: Sawan, M (Ed.): pp. 122, IFESS_2005, Montreal, Canada, 2005.
Abstract | Links | BibTeX | Tags: FES Technologies & Techniques
@inproceedings{IFESS2005_122,
title = {Transcutaneous Electrode Measurement System},
author = {M Lawrence and T A Keller},
editor = {M Sawan},
url = {https://ifess.org/files/proceedings/IFESS2005/IFESS2005_122_Lawrence.pdf},
year = {2005},
date = {2005-07-01},
pages = {122},
publisher = {IFESS_2005},
address = {Montreal, Canada},
abstract = {Arrays of transcutaneous electrode elements have been proposed as a method to improve selective muscle stimulation and functional control. Measuring the current distribution across the surface of these electrode elements is important for understanding how the electric field penetrates into human tissue. A new measurement system has been developed that simulates human skin at the electrode interface. Small structures were incorporated, allowing localised changes in skin impedance to be simulated. Current flow through the measurement system was recorded and used to produce current distribution maps at the simulated electrode skin interface. First measurements indicated that coupling gel helped to uniformly distribute stimulation current across the surface of the electrode. Simulating localised changes in skin impedance produced large current densities and non-uniform current distributions, which is in agreement with published literature.},
keywords = {FES Technologies & Techniques},
pubstate = {published},
tppubtype = {inproceedings}
}
Arrays of transcutaneous electrode elements have been proposed as a method to improve selective muscle stimulation and functional control. Measuring the current distribution across the surface of these electrode elements is important for understanding how the electric field penetrates into human tissue. A new measurement system has been developed that simulates human skin at the electrode interface. Small structures were incorporated, allowing localised changes in skin impedance to be simulated. Current flow through the measurement system was recorded and used to produce current distribution maps at the simulated electrode skin interface. First measurements indicated that coupling gel helped to uniformly distribute stimulation current across the surface of the electrode. Simulating localised changes in skin impedance produced large current densities and non-uniform current distributions, which is in agreement with published literature.