RESUMO
We present the time course of change in the muscle transcriptome 1 h after the last exercise bout of a daily resistance training program lasting 2, 10, 20, or 30 days. Daily exercise in rat tibialis anterior muscles (5 sets of 10 repetitions over 20 min) induced progressive muscle growth that approached a new stable state after 30 days. The acute transcriptional response changed along with progressive adaptation of the muscle phenotype. For example, expression of type 2B myosin was silenced. Time courses recently synthesized from human exercise studies do not demonstrate so clearly the interplay between the acute exercise response and the longer-term consequences of repeated exercise. We highlight classes of transcripts and transcription factors whose expression increases during the growth phase and declines again as the muscle adapts to a new daily pattern of activity and reduces its rate of growth. Myc appears to play a central role.
Assuntos
Condicionamento Físico Humano , Treinamento Resistido , Humanos , Animais , Ratos , Aclimatação , Músculos , FenótipoRESUMO
Multichannel bio-signal recording in undisturbed in vivo conditions is a frequent demand in experimental work for development of methodology and associated equipment for functional electrical stimulation (FES) application, limb prosthesis, and diagnostic tools in contemporary rehabilitation efforts. Intramuscular electromyogram (EMG) recordings can provide comprehensive insight in complex interactions of agonistic and antagonistic muscles during movement tasks and in contrast act as reliable control signals for both neuroprosthesis and mechanical prosthesis. We fabricated a fully implantable device, which is capable of recording electromyography signals from inside a body and transmit these signals wirelessly to an external receiver. The developed analog front end uses only two electrodes per channel, provides a gain of 60 dB, and incorporates a band pass filter with lower cut-off frequency of 4 Hz and upper cut-off frequency of 480 Hz. The bidirectional wireless data link, which operates in the 2.4 GHz Industrial, Scientific and Medical band, is designed for transmission distances of 10 m using an application data rate of 1 kSps for each of the two channels. Performed in vitro tests with the devices coated in epoxy resin and inserted into a phantom with tissue-equivalent characteristics confirmed the functionality of our concept and the measurement results are consistent with those from preceding simulations.
Assuntos
Eletrodos Implantados , Eletromiografia/métodos , Telemetria/métodos , Animais , Terapia por Estimulação Elétrica/métodos , Eletromiografia/instrumentação , Técnicas In Vitro , Músculo Esquelético/fisiologiaRESUMO
OBJECTIVES: The aim of the study was to increase muscle volume and improve phonation characteristics of the aged ovine larynx by functional electrical stimulation (FES) using a minimally invasive surgical procedure. METHODS: Stimulation electrodes were placed bilaterally near the terminal adduction branch of the recurrent laryngeal nerves (RLN). The electrodes were connected to battery powered pulse generators implanted subcutaneously at the neck region. Training patterns were programmed by an external programmer using a bidirectional radio frequency link. Training sessions were repeated automatically by the implant every other day for 1 week followed by every day for 8 weeks in the awake animal. Another group of animals were used as sham, with electrodes positioned but not connected to an implant. Outcome parameters included gene expression analysis, histological assessment of muscle fiber size, functional analysis, and volumetric measurements based on three-dimensional reconstructions of the entire thyroarytenoid muscle (TAM). RESULTS: Increase in minimal muscle fiber diameter and an improvement in vocal efficiency were observed following FES, compared with sham animals. CONCLUSION: This is the first study to demonstrate beneficial effects in the TAM of FES at molecular, histological, and functional levels. FES of the terminal branches of the RLN reversed the effects of age-related changes and improved vocal efficiency. LEVEL OF EVIDENCE: NA Laryngoscope, 134:848-854, 2024.
Assuntos
Terapia por Estimulação Elétrica , Paralisia das Pregas Vocais , Ovinos , Animais , Modelos Animais de Doenças , Músculos Laríngeos/inervação , Terapia por Estimulação Elétrica/métodos , Estimulação Elétrica/métodosRESUMO
According to PubMed, roughly 10% of the annually added publications are describing findings from the small animal model (mice and rats), including investigations in the field of muscle physiology and training. A subset of this research requires neural stimulation with flexible adjustments of stimulation parameters, highlighting the need for reliable implantable electrical stimulators, small enough (~1 cm3), that even mice can tolerate them without impairing their movement. The MiniVStimA is a battery-powered implant for nerve stimulation with an outer diameter of 15 mm and an encapsulated volume of 1.2 cm3 in its smallest variation. It can be pre-programmed according to the experimental protocol and controlled after implantation with a magnet. It delivers constant current charge-balanced monophasic rectangular pulses up to 2 mA and 1 ms phase width (1 kΩ load). The circuitry is optimized for small volume and energy efficiency. Due to the variation of the internal oscillator (31 kHz ± 10%), calibration measures must be implemented during the manufacturing process, which can reduce the deviation of the frequency related parameters down to ± 1%. The expected lifetime of the smaller (larger) version is 100 (480) days for stimulation with 7 Hz all day and 10 (48) days for stimulation with 100 Hz. Devices with complex stimulation patterns for nerve stimulation have been successfully used in two in-vivo studies, lasting up to nine weeks. The implant worked fully self-contained while the animal stayed in its familiar environment. External components are not required during the entire time.
Assuntos
Estimulação Elétrica/instrumentação , Eletrodos Implantados , Animais , Animais de Laboratório , Desenho de Equipamento , Feminino , Camundongos , Ratos , Ratos WistarRESUMO
BACKGROUND: A sudden failure of implantable pulse generators (IPG) occurred in 15 out of 143 units during the last 4 years in our patients. This corresponds to a failure rate of 10.5%. In all cases, the connection between the causes of battery and electronic circuit was found defective in the destructive analysis. In order to better understand the failure causes we proceeded to an analysis of explanted IPGs which had reached their normal life span due to depletion of the battery. METHOD: A functional test and an intensive destructive analysis were carried out in 14 units. The internal parts of the IPG were inspected by light and electron microscopy. FINDINGS: Deformations of the connection between battery and electronic circuit could be found in 12 out of 14 IPGs. The epoxy bonds, which achieve the mechanical fixation between the two contact areas of the bond wires, were found separated in 86%. Additionally, in six out of 14 devices the bond wires were either found lifted or with cracks as a sign of material fatigue. CONCLUSION: Based on these results we conclude that the IPGs of the affected series did have a technical weak spot. We presume that this issue appears systematically and not randomly or triggered by an unusual action of the patient.
Assuntos
Estimulação Encefálica Profunda/instrumentação , Eletrônica Médica/instrumentação , Análise de Falha de Equipamento/métodos , Falha de Equipamento/estatística & dados numéricos , Segurança de Equipamentos/métodos , Estimulação Encefálica Profunda/efeitos adversos , Estimulação Encefálica Profunda/métodos , Eletrodos Implantados/normas , Eletrônica Médica/métodos , Eletrônica Médica/normas , Compostos de Epóxi/normas , Segurança de Equipamentos/normas , Humanos , Complicações Intraoperatórias/etiologia , Complicações Intraoperatórias/prevenção & controle , Doença de Parkinson/terapia , Controle de QualidadeRESUMO
OBJECTIVES/HYPOTHESIS: To reverse sarcopenia and increase the volumes of atrophied laryngeal muscles by functional electrical stimulation (FES) using a minimal invasive surgical procedure in an aged ovine model. STUDY DESIGN: Prospective animal study. METHODS: A stimulation electrode was placed unilaterally near the terminal adduction branch of the recurrent laryngeal nerve (RLN) adjacent to the right cricothyroid joint. The electrode was connected to an implant located subcutaneously at the neck region. Predesigned training patterns were automatically delivered by a bidirectional radio frequency link using a programming device and were repeated automatically by the implant every other day over 11 weeks in the awake animal. Outcome parameters comprised volumetric measurements based on three-dimensional reconstructions of the entire thyroarytenoid muscle (TAM), as well as gene expression analyses. RESULTS: We found significant increases of the volumes of the stimulated TAM of 11% and the TAM diameter at the midmembranous parts of the vocal folds of nearly 40%. Based on gene expression, we did not detect a shift of muscle fiber composition. CONCLUSIONS: FES of the terminal branches of the RLN is a secure and effective way to reverse the effects of age-related TAM atrophy and to increase volumes of atrophied muscles. LEVEL OF EVIDENCE: NA Laryngoscope, 128:2852-2857, 2018.
Assuntos
Estimulação Elétrica/métodos , Músculos Laríngeos/diagnóstico por imagem , Nervo Laríngeo Recorrente/fisiopatologia , Paralisia das Pregas Vocais/terapia , Animais , Modelos Animais de Doenças , Feminino , Imageamento Tridimensional , Músculos Laríngeos/inervação , Estudos Prospectivos , Ovinos , Paralisia das Pregas Vocais/diagnósticoRESUMO
The influence of loading on muscular hypertrophy has previously been studied in rodents by removal of synergistic muscles or various weight-lifting regimes. We present a novel model, evoking hypertrophy in the rat's tibialis anterior (TA) muscle by means of an implanted single channel electrical nerve stimulator. The amount of load experienced by the TA was measured in acute experiments in anaesthetized rats with contractions over a range of stimulation frequency and amplitude. A novel electrode configuration allowed us to elicit concentric, isometric and eccentric contractions within the same setup. This was achieved by 'SpillOver' stimulation in which we adjusted the amount of co-activation of the stronger antagonistic plantarflexors by increasing the stimulus above the level that caused full recruitment of the dorsiflexor muscles. The effect of loading on hypertrophy of the TA was tested in 3-4 week stimulation experiments in two groups of freely-moving rats, with a protocol that resembles typical resistance-training in humans. One group performed concentric contractions with no antagonistic co-contraction (unloaded, UNL, n = 5). In the other group the TA was loaded by simultaneous co-contraction of the antagonistically acting plantarflexors (SpillOver, n = 5). The wet mass of the stimulated TA increased in both groups; by 5.4 ± 5.5% for the UNL-group and 13.9 ± 2.9% for the SpillOver-group, with significantly greater increase in the SpillOver-group (p<0.05). Our results correlate well with values reported in literature, demonstrating that SpillOver-stimulation is a suitable model in which to study muscular hypertrophy. Even higher gains in muscle-mass may be possible by optimizing and adjusting the stimulation parameters according to the principles of progressive resistance training.
Assuntos
Estimulação Elétrica , Pé , Contração Muscular , Músculo Esquelético/patologia , Músculo Esquelético/fisiopatologia , Tíbia , Animais , Fenômenos Biomecânicos , Modelos Animais de Doenças , Hipertrofia , Masculino , Tamanho do Órgão , Ratos , Ratos Wistar , Suporte de CargaRESUMO
A sudden failure of implantable pulse generators used for spinal cord stimulation occurred in two patients. To identify the cause of this failure, an intensive destructive analysis of the explanted devices was carried out. A functional diagnosis was carried out by inspecting amplitude, pulse width and frequency on each output channel of the implantable pulse generators. Later, the titanium case of the pulse generators was opened by laser cutting to minimise any additional mechanical stress during the opening procedure. The functional test for both pulse generators showed faultless behaviour. Using light and electron microscopy, hairline cracks could be identified in the electrical connection between battery and electronic circuit. In both devices, the cracks spread through the whole bond wire in the connection to the plus pole of the battery and partially also to the minus pole. The analysis showed that both devices failed by broken bond wires. The electrical connection to the battery exists just by the spring characteristic of the wires. A push to the implant causes a short-term disconnection, resulting in a power on reset of the device. Manufacturing or design issues, allowing micromotion between battery and the hybrid part, may be the reason for this problem.
Assuntos
Terapia por Estimulação Elétrica/instrumentação , Eletrônica Médica/instrumentação , Falha de Equipamento , Processamento de Sinais Assistido por Computador/instrumentação , Terapia por Estimulação Elétrica/métodos , Eletrônica Médica/métodos , Desenho de Equipamento , Análise de Falha de EquipamentoRESUMO
Direct measurements of muscular forces usually require a substantial rearrangement of the biomechanical system. To circumvent this problem, various indirect techniques have been used in the past. We introduce a novel direct method, using a lightweight (~0.5 g) miniature (3 x 3 x 7 mm) in-line load-cell to measure tension in the tibialis anterior tendon of rats. A linear motor was used to produce force-profiles to assess linearity, step-response, hysteresis and frequency behavior under controlled conditions. Sensor responses to a series of rectangular force-pulses correlated linearly (R2 = 0.999) within the range of 0-20 N. The maximal relative error at full scale (20 N) was 0.07% of the average measured signal. The standard deviation of the mean response to repeated 20 N force pulses was ± 0.04% of the mean response. The step-response of the load-cell showed the behavior of a PD2T2-element in control-engineering terminology. The maximal hysteretic error was 5.4% of the full-scale signal. Sinusoidal signals were attenuated maximally (-4 dB) at 200 Hz, within a measured range of 0.01-200 Hz. When measuring muscular forces this should be of minor concern as the fusion-frequency of muscles is generally much lower. The newly developed load-cell measured tensile forces of up to 20 N, without inelastic deformation of the sensor. It qualifies for various applications in which it is of interest directly to measure forces within a particular tendon causing only minimal disturbance to the biomechanical system.
Assuntos
Teste de Materiais/instrumentação , Miniaturização/instrumentação , Tendões/fisiologia , Resistência à Tração , Tíbia , Animais , Fenômenos Biomecânicos , Masculino , Ratos , Ratos Wistar , Suporte de CargaRESUMO
Tensile-force transmitted by the tibialis anterior (TA) tendon of 11 anesthetized adult male Wistar rats (body-mass: 360.6 ± 66.3 g) was measured in-situ within the intact biomechanical system of the hind-limb using a novel miniature in-line load-cell. The aim was to demonstrate the dependence of the loading-profile experienced by the muscle, on stimulation-frequency and the resistance to shortening in a group of control-animals. Data from these acute-experiments shows the type of loading achievable by means of implantable electrical stimulators activating agonists or agonist/antagonist groups of muscles during programmed resistance-training in freely moving healthy subjects. Force-responses to electrical stimulation of the common peroneal nerve for single pulses and short bursts were measured in unloaded and isometric contractions. A less time-consuming approach to measure the force-frequency relationship was investigated by applying single bursts containing a series of escalating stimulus-frequencies. We also measured the range of loading attainable by programmed co-contraction of the TA-muscle with the plantar-flexor muscles for various combinations of stimulation-frequencies. The maximal average peak-force of single twitches was 179% higher for isometric than for unloaded twitches. Average maximal isometric tetanic-force per gramme muscle-mass was 16.5 ± 3.0 N g-1, which agrees well with other studies. The standard and time-saving approaches to measure the force-frequency relationship gave similar results. Plantar-flexor co-activation produced greatly increased tension in the TA-tendon, similar to isometric contractions. Our results suggest that unloaded contractions may not be adequate for studies of resistance-training. Plantar-flexor co-contractions produced considerably higher force-levels that may be better suited to investigate the physiology and cell-biology of resistance-training in rodents.
Assuntos
Contração Isométrica , Músculo Esquelético/fisiologia , Tendões/fisiologia , Resistência à Tração , Animais , Masculino , Músculo Esquelético/inervação , Condicionamento Físico Animal , Ratos , Ratos WistarRESUMO
[This corrects the article DOI: 10.1371/journal.pone.0167367.].
RESUMO
Age related atrophy of the laryngeal muscles -mainly the thyroarytenoid muscle (TAM)- leads to a glottal gap and consequently to a hoarse and dysphonic voice that significantly affects quality of life. The aim of our study was to reverse this atrophy by inducing muscular hypertrophy by unilateral functional electrical stimulation (FES) of the recurrent laryngeal nerve (RLN) in a large animal model using aged sheep (n = 5). Suitable stimulation parameters were determined by fatiguing experiments of the thyroarytenoid muscle in an acute trial. For the chronic trial an electrode was placed around the right RLN and stimulation was delivered once daily for 29 days. We chose a very conservative stimulation pattern, total stimulation time was two minutes per day, or 0.14% of total time. Overall, the mean muscle fiber diameter of the stimulated right TAM was significantly larger than the non-stimulated left TAM (30µm±1.1µm vs. 28µm±1.1 µm, p<0.001). There was no significant shift in fiber type distribution as judged by immunohistochemistry. The changes of fiber diameter could not be observed in the posterior cricoarytenoid muscle (PCAM). FES is a possible new treatment option for reversing the effects of age related laryngeal muscle atrophy.
Assuntos
Modelos Animais de Doenças , Terapia por Estimulação Elétrica/métodos , Músculos Laríngeos/patologia , Traumatismos do Nervo Laríngeo Recorrente/terapia , Nervo Laríngeo Recorrente/patologia , Paralisia das Pregas Vocais/fisiopatologia , Fatores Etários , Animais , Feminino , Qualidade de Vida , OvinosRESUMO
As the number of donor hearts is limited while more and more patients suffer from end stage biventricular heart failure, Total Artificial Hearts become a promising alternative to conventional treatment. While pneumatic devices sufficiently supply the patients with blood flow, the patient's quality of life is limited by the percutaneous pressure lines and the size of the external control unit. This paper describes the development of the control unit of the ReinHeart, a fully implantable Total Artificial Heart. General requirements for any implantable control unit are defined from a technical and medical point of view: necessity of a Transcutaneous Energy Transmission, autonomous operation, safety, geometry, and efficiency. Based on the requirements, a prototype is designed; it incorporates a LiFePo4 battery pack with charger, a rectifier for transcutaneous energy transmission, the motor's driver electronics, and a microcontroller which monitors and controls all functions. In validation tests, the control unit demonstrated a stable operation on TET and battery supply and a safe switching from one supply to the other. The overall mean efficiency is 14% on TET and 22% on battery supply. The control unit is suitable for chronic animal trials of the ReinHeart.
Assuntos
Insuficiência Cardíaca/terapia , Coração Artificial , Coração Auxiliar , Hemodinâmica , Animais , Insuficiência Cardíaca/fisiopatologia , Humanos , Qualidade de VidaRESUMO
BACKGROUND: Typically, electrodes for Deep Brain Stimulation (DBS) are used for chronic stimulation. However, there are conditions where this therapy has to be discontinued. In such cases using the DBS electrodes as a tool for thermo-lesioning (coagulation) could be used for an alternative treatment. The aim of this study was to determine if it is possible to generate coagula with a predictable geometry and to define their dimensions as a function of power and time in an in vitro model (egg white at room temperature). Furthermore, we tested if repetitive (cumulative) coagulation has an impact on the overall form and size of the clot. FINDINGS: Coagulation-growth was achieved as a function of power and duration of coagulation; reproducible well-formed thermocoagulations could be achieved. When using two adjacent electrodes a power range between 1.25 Watt and 2.00 Watt resulted in homogenous ovoid coagula. After two minutes of coagulation the clots reached a maximum in size and further growth could not be achieved. It was also possible to increase the size of a preformed clot by repetitive coagulation either by increasing the power level or the duration of the coagulation process. CONCLUSIONS: We could show that it is possible to obtain predictable coagula in-vitro when using DBS electrodes for thermocoagulation even though they have not been developed for that specific purpose. However, until in-vivo safety and efficacy of DBS electrodes for ablation purposes is properly assessed, only approved electrodes should be used for brain ablation.
RESUMO
Muscular atrophy due to denervation can be substantially reversed by direct electrical stimulation. Some muscle properties are, however, resistant to change. Using a rabbit model of established denervation atrophy, we investigated whether the extent of restoration would vary with the stimulation protocol. Five patterns, delivering 24,000-480,000 impulses/day, were applied for 6 or 10 weeks. The wet weight, cross-sectional area, tetanic tension, shortening velocity, and power of denervated muscles subjected to stimulation all increased significantly. The fibers were larger and more closely packed and there was no evidence of necrosis. There was a small increase in excitability. Isometric twitch kinetics remained slow and fatigue resistance did not improve. The actual pattern of stimulation had no influence on any of these findings. The results, interpreted in the context of ultrastructural changes and an ongoing clinical study, reaffirm the clinical value of introducing stimulation during the initial non-degenerative phase. They indicate that there would be little therapeutic benefit in adopting regimes more energetically demanding than those in current use, and that the focus should now shift to protocols that represent the least intrusion into activities of daily living.
Assuntos
Terapia por Estimulação Elétrica , Denervação Muscular , Músculo Esquelético/patologia , Músculo Esquelético/fisiologia , Animais , Atrofia , Eletrodos Implantados , Membro Posterior/inervação , Contração Isométrica , Articulações/inervação , Articulações/fisiologia , Masculino , Contração Muscular/fisiologia , Fibras Musculares Esqueléticas/fisiologia , Músculo Esquelético/inervação , Degeneração Neural/patologia , Degeneração Neural/fisiopatologia , Regeneração Nervosa/fisiologia , Coelhos , Análise de RegressãoRESUMO
We investigated the extent to which activity induced by chronic electrical stimulation could restore the mass and contractile function of rabbit tibialis anterior (TA) muscles that had undergone atrophy as a result of prolonged denervation. Denervation was carried out by selectively interrupting the motor nerve branches to the ankle dorsiflexors in one hind limb. Stimulators were implanted, with electrodes on the superficial and deep surfaces of the denervated TA muscle. Ten weeks later, the mass and mid-belly cross-sectional area (CSA) of TA muscles subjected to denervation alone had fallen to approximately 40% of normal. At this stage, stimulators in the other rabbits were activated for 1 h/day to deliver 20-ms rectangular bipolar constant-current pulses of 4 mA amplitude at 20 Hz with a duty cycle of 1s ON/2s OFF, a total of 24,000 impulses/day. The animals were examined after a further 2, 6 or 10 weeks. Stimulation restored the wet weight of the denervated muscles to values not significantly different to those of normal, innervated controls. It increased CSA from 39% to 66% of normal, and there was a commensurate increase in maximum isometric tetanic force from 27% to 50% of normal. Light and electron microscopic examination revealed a marked improvement in the size, packing, and internal organization of the stimulated-denervated muscle fibres, suggestive of an ongoing process of restoration. Excitability, contractile speed, power, and fatigue resistance had not, however, been restored to normal levels after 10 weeks of stimulation. Similar results were found for muscles that had been denervated for 39 weeks and then stimulated for 12 weeks. The study demonstrates worthwhile benefits of long-term electrical stimulation in the treatment of established denervation atrophy.
Assuntos
Terapia por Estimulação Elétrica/métodos , Membro Posterior/fisiopatologia , Músculo Esquelético/fisiopatologia , Atrofia Muscular/terapia , Animais , Denervação/efeitos adversos , Eletrodos Implantados , Membro Posterior/inervação , Membro Posterior/patologia , Masculino , Microscopia Eletrônica de Transmissão , Contração Muscular/fisiologia , Fibras Musculares Esqueléticas/patologia , Fibras Musculares Esqueléticas/fisiologia , Debilidade Muscular/etiologia , Debilidade Muscular/fisiopatologia , Debilidade Muscular/terapia , Músculo Esquelético/inervação , Músculo Esquelético/patologia , Atrofia Muscular/etiologia , Atrofia Muscular/fisiopatologia , Coelhos , Fatores de Tempo , Resultado do TratamentoRESUMO
Measurements of the rheobase and chronaxie can be used to define the excitability of nerves and muscles. The aim of this study was to obtain a record over many weeks of changes in the rheobase and chronaxie of denervated rabbit tibialis anterior muscle (TA). A custom-built electronic stimulator was implanted into the peritoneal cavity of New Zealand White rabbits. Large stainless steel electrodes were placed on the denervated TA muscle. Rheobase and chronaxie were measured noninvasively at weekly intervals by means of a laptop PC, which communicated with the stimulator via a radio-frequency link. At each setting the denervated TA was palpated manually to detect the response of the muscle. During the first few days after denervation the rheobase increased transiently to 0.8 +/- 0.13 mA, approximately twice the value for normal innervated muscle, then decreased to normal for the remainder of the experimental period. Chronaxie underwent a significant 3-fold increase from 4.5 +/- 1.1 ms to 14.1 +/- 1.1 ms during the first two weeks of denervation and remained elevated throughout. The custom-built implantable electronic stimulator allowed changes in muscle excitability to be studied over a long period of denervation within individual animals, providing an accurate assessment of the time course of denervation-induced changes in muscle excitability.
Assuntos
Estimulação Elétrica/métodos , Extremidade Inferior/fisiopatologia , Denervação Muscular/efeitos adversos , Músculo Esquelético/fisiopatologia , Análise de Variância , Animais , Cronaxia , Contração Muscular/fisiologia , CoelhosRESUMO
A new tonometric test system to assess surface stiffness over relaxed and activated calf muscles was developed. The mechanical arrangement consists of a skin indentor driven by a torque motor (galvo-drive) that is rigidly connected to an ankle dynamometer. The indentation depth is measured by a displacement transducer. Software routines for cyclic indentation (recording of stiffness curves), static indentation (sensing of twitch responses), and vibration (skin resonance) were implemented. A visual interface is used to capture surface stiffness during target contractions and during controlled relaxation. For functional electrical stimulation (FES) applications, the software includes a pulse train synthesizer to generate arbitrary stimulation test patterns. The system's performance was tested in FES and voluntary contraction procedures.
Assuntos
Sistemas Computacionais , Músculo Esquelético/fisiologia , Tonometria Ocular , Estimulação Elétrica Nervosa Transcutânea , Fenômenos Biomecânicos , Humanos , Perna (Membro) , Contração Muscular/fisiologia , Relaxamento Muscular/fisiologiaRESUMO
An eight-channel stimulation system, currently intended for stimulation of lower extremities, was developed and is introduced. The major development goals were easy handling, modularity to make the system easily adaptable for other functional electrical stimulation (FES) applications, and a wide stimulation parameter range for application-specific parameter optimization. For paraplegic stepping, the system worn by the patient consists of 2 four-channel stimulation modules, a central unit holding the battery and circuitry for power management and communication control, a wireless remote control unit, and a palmtop computer as the main control and input device. A software package for Microsoft Windows supports the design and optimization of stimulation sequences in the rehabilitation center. First tests with patients familiar with FES showed smoother movements during stepping and acceptable good handling. In combination with the PC software, the required stimulation sequences could be created in a very short time.