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Majdi JA, Acuña SA, Chitnis PV, Sikdar S. Toward a wearable monitor of local muscle fatigue during electrical muscle stimulation using tissue Doppler imaging. WEARABLE TECHNOLOGIES 2022; 3:e16. [PMID: 38486895 PMCID: PMC10936279 DOI: 10.1017/wtc.2022.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 05/26/2022] [Accepted: 06/12/2022] [Indexed: 03/17/2024]
Abstract
Electrical muscle stimulation (EMS) is widely used in rehabilitation and athletic training to generate involuntary muscle contractions. However, EMS leads to rapid muscle fatigue, limiting the force a muscle can produce during prolonged use. Currently available methods to monitor localized muscle fatigue and recovery are generally not compatible with EMS. The purpose of this study was to examine whether Doppler ultrasound imaging can assess changes in stimulated muscle twitches that are related to muscle fatigue from electrical stimulation. We stimulated five isometric muscle twitches in the medial and lateral gastrocnemius of 13 healthy subjects before and after a fatiguing EMS protocol. Tissue Doppler imaging of the medial gastrocnemius recorded muscle tissue velocities during each twitch. Features of the average muscle tissue velocity waveforms changed immediately after the fatiguing stimulation protocol (peak velocity: -38%, p = .022; time-to-zero velocity: +8%, p = .050). As the fatigued muscle recovered, the features of the average tissue velocity waveforms showed a return towards their baseline values similar to that of the normalized ankle torque. We also found that features of the average tissue velocity waveform could significantly predict the ankle twitch torque for each participant (R2 = 0.255-0.849, p < .001). Our results provide evidence that Doppler ultrasound imaging can detect changes in muscle tissue during isometric muscle twitch that are related to muscle fatigue, fatigue recovery, and the generated joint torque. Tissue Doppler imaging may be a feasible method to monitor localized muscle fatigue during EMS in a wearable device.
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Affiliation(s)
- Joseph A. Majdi
- Department of Bioengineering, George Mason University, Fairfax, Virginia, USA
- Center for Adaptive Systems of Brain–Body Interactions, George Mason University, Fairfax, Virginia, USA
| | - Samuel A. Acuña
- Department of Bioengineering, George Mason University, Fairfax, Virginia, USA
- Center for Adaptive Systems of Brain–Body Interactions, George Mason University, Fairfax, Virginia, USA
| | - Parag V. Chitnis
- Department of Bioengineering, George Mason University, Fairfax, Virginia, USA
- Center for Adaptive Systems of Brain–Body Interactions, George Mason University, Fairfax, Virginia, USA
| | - Siddhartha Sikdar
- Department of Bioengineering, George Mason University, Fairfax, Virginia, USA
- Center for Adaptive Systems of Brain–Body Interactions, George Mason University, Fairfax, Virginia, USA
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Hayami N, Williams HE, Shibagaki K, Vette AH, Suzuki Y, Nakazawa K, Nomura T, Milosevic M. Development and Validation of a Closed-Loop Functional Electrical Stimulation-Based Controller for Gait Rehabilitation Using a Finite State Machine Model. IEEE Trans Neural Syst Rehabil Eng 2022; 30:1642-1651. [PMID: 35709114 DOI: 10.1109/tnsre.2022.3183571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Functional electrical stimulation (FES) can be used to initiate lower limb muscle contractions and has been widely applied in gait rehabilitation. Establishing the correct timing of FES activation during each phase of the gait (walking) cycle remains challenging as most FES systems rely on open-loop control, whereby the controller receives no feedback about joint kinematics and instead relies on predetermined/timed muscle stimulation. The objective of this study was to develop and validate a closed-loop FES-based control solution for gait rehabilitation using a finite state machine (FSM) model. A two-phased study approach was taken: (1) Experimentally-Informed Study: A neuromuscular-derived FSM model was developed to drive closed-loop FES-based control for gait rehabilitation. The finite states were determined using electromyography and joint kinematics data of 12 non-disabled adults, collected during treadmill walking. The gait cycles were divided into four states, namely: swing-to-stance, push off, pre-swing, and toe up. (2) Simulation Study: A closed-loop FES-based control solution that employed the resulting FSM model, was validated through comparisons of neuro-musculo-skeletal computer simulations of impaired versus healthy gait. This closed-loop controller yielded steadier simulated impaired gait, in comparison to an open-loop alternative. The simulation results confirmed that accurate timing of FES activation during the gait cycle, as informed by kinematics data, is important to natural gait retraining. The closed-loop FES-based solution, introduced in this study, contributes to the repository of gait rehabilitation control options and offers the advantage of being simplistic to implement. Furthermore, this control solution is expected to integrate well with powered exoskeleton technologies.
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Joint angle based motor point tracking stimulation for surface FES: A Study on biceps brachii. Med Eng Phys 2021; 88:9-18. [PMID: 33485518 DOI: 10.1016/j.medengphy.2020.11.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 10/16/2020] [Accepted: 11/25/2020] [Indexed: 11/20/2022]
Abstract
Functional electrical stimulation (FES) has been an effective treatment option in clinical rehabilitation such as motor function recovery after stroke. The main limitation of FES is the lack of stimulation efficiency in motor unit recruitment compared with voluntary contractions, which may cause the early onset of muscle fatigue. The stimulation efficiency of FES can be improved by optimizing electrode positions to target the motor point (MP). However, the location of MP relative to the skin may shift with the change of muscle geometry during dynamic exercise. Hence, the purpose of this study is to maintain the stimulation efficiency of FES in dynamic exercise by switching the stimulation position to follow the shift of MP. We first measured the shift of the MP of the biceps brachii with respect to the elbow joint angle, and then conducted an experiment to compare four stimulation methods: 2-channel simultaneous stimulation (SS), 2-channel time based shifting stimulation (TSS), 2-channel joint angle based shifting stimulation (JASS), and 3-channel JASS. TSS and JASS were designed as two different MP tracking strategies. The experimental results show that the 3-channel JASS caused the smallest decrease in the maximal elbow angle and the angular velocity. The results also suggest that MP tracking stimulation based on joint angle is effective for the sustainable induction of muscle contraction. Both tracking selectivity and tracking density were shown to be important to improve the stimulation efficiency of FES.
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Ruslee R, Miller J, Gollee H. Investigation of different stimulation patterns with doublet pulses to reduce muscle fatigue. J Rehabil Assist Technol Eng 2019; 6:2055668319825808. [PMID: 31245029 PMCID: PMC6582293 DOI: 10.1177/2055668319825808] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 12/18/2018] [Indexed: 11/29/2022] Open
Abstract
Introduction: Functional electrical stimulation is a common
technique used in the rehabilitation of individuals with a spinal cord injury to
produce functional movement of paralysed muscles. However, it is often
associated with rapid muscle fatigue which limits its applications.
Methods: The objective of this study is to investigate the
effects on the onset of fatigue of different multi-electrode patterns of
stimulation via multiple pairs of electrodes using doublet pulses: Synchronous
stimulation is compared to asynchronous stimulation patterns which are activated
sequentially (AsynS) or randomly (AsynR), mimicking voluntary muscle activation
by targeting different motor units. We investigated these three different
approaches by applying stimulation to the gastrocnemius muscle repeatedly for
10 min (300 ms stimulation followed by 700 ms of no-stimulation) with 40 Hz
effective frequency for all protocols and doublet pulses with an
inter-pulse-interval of 6 ms. Eleven able-bodied volunteers (28 ± 3 years old)
participated in this study. Ultrasound videos were recorded during stimulation
to allow evaluation of changes in muscle morphology. The main fatigue indicators
we focused on were the normalised fatigue index, fatigue time interval and
pre-post twitch–tetanus ratio. Results: The results demonstrate
that asynchronous stimulation with doublet pulses gives a higher normalised
fatigue index (0.80 ± 0.08 and 0.87 ± 0.08) for AsynS and AsynR, respectively,
than synchronous stimulation (0.62 ± 0.06). Furthermore, a longer fatigue time
interval for AsynS (302.2 ± 230.9 s) and AsynR (384.4 ± 279.0 s) compared to
synchronous stimulation (68.0 ± 30.5 s) indicates that fatigue occurs later
during asynchronous stimulation; however, this was only found to be
statistically significant for one of two methods used to calculate the group
mean. Although no significant difference was found in pre-post twitch–tetanus
ratio, there was a trend towards these effects. Conclusion: In this
study, we proposed an asynchronous stimulation pattern for the application of
functional electrical stimulation and investigated its suitability for reducing
muscle fatigue compared to previous methods. The results show that asynchronous
multi-electrode stimulation patterns with doublet pulses may improve fatigue
resistance in functional electrical stimulation applications in some
conditions.
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Affiliation(s)
- Ruslinda Ruslee
- Centre for Rehabilitation Engineering, University of Glasgow, Glasgow, UK.,Department of Electronics Engineering, MARA Japan Industrial Institute (MJII), Beranang, Selangor, Malaysia
| | - Jennifer Miller
- Centre for Rehabilitation Engineering, University of Glasgow, Glasgow, UK
| | - Henrik Gollee
- Centre for Rehabilitation Engineering, University of Glasgow, Glasgow, UK
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Laubacher M, Aksoez EA, Brust AK, Baumberger M, Riener R, Binder-Macleod S, Hunt KJ. Stimulation of paralysed quadriceps muscles with sequentially and spatially distributed electrodes during dynamic knee extension. J Neuroeng Rehabil 2019; 16:5. [PMID: 30616683 PMCID: PMC6322281 DOI: 10.1186/s12984-018-0471-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 12/05/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND During functional electrical stimulation (FES) tasks with able-bodied (AB) participants, spatially distributed sequential stimulation (SDSS) has demonstrated substantial improvements in power output and fatigue properties compared to conventional single electrode stimulation (SES). The aim of this study was to compare the properties of SDSS and SES in participants with spinal cord injury (SCI) in a dynamic isokinetic knee extension task simulating knee movement during recumbent cycling. METHOD Using a case-series design, m. vastus lateralis and medialis of four participants with motor and sensory complete SCI (AIS A) were stimulated for 6 min on both legs with both electrode setups. With SES, target muscles were stimulated by a pair of electrodes. In SDSS, the distal electrodes were replaced by four small electrodes giving the same overall stimulation frequency and having the same total surface area. Torque was measured during knee extension by a dynamometer at an angular velocity of 110 deg/s. Mean power of the left and right sides (PmeanL,R) was calculated from all stimulated extensions for initial, final and all extensions. Fatigue is presented as an index value with respect to initial power from 1 to 0, whereby 1 means no fatigue. RESULTS SDSS showed higher PmeanL,R values for all four participants for all extensions (increases of 132% in participant P1, 100% in P2, 36% in P3 and 18% in P4 compared to SES) and for the initial phase (increases of 84%, 59%, 66%, and 16%, respectively). Fatigue resistance was better with SDSS for P1, P2 and P4 but worse for P3 (0.47 vs 0.35, 0.63 vs 0.49, 0.90 vs 0.82 and 0.59 vs 0.77, respectively). CONCLUSION Consistently higher PmeanL,R was observed for all four participants for initial and overall contractions using SDSS. This supports findings from previous studies with AB participants. Fatigue properties were better in three of the four participants. The lower fatigue resistance with SDSS in one participant may be explained by a very low muscle activation level in this case. Further investigation in a larger cohort is warranted.
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Affiliation(s)
- Marco Laubacher
- Department of Physical Therapy, University of Delaware, Newark, United States of America.
| | - Efe A Aksoez
- Department of Physical Therapy, University of Delaware, Newark, United States of America
| | - Anne K Brust
- Department of Physical Therapy, University of Delaware, Newark, United States of America
| | - Michael Baumberger
- Institute for Rehabilitation and Performance Technology, Division of Mechanical Engineering, Department of Engineering and Information Technology, Bern University of Applied Sciences, Pestalozzistrasse 20, Burgdorf, 3400, Switzerland.,Sensory Motor Systems Lab, Department of Health Sciences and Technology, ETH Zurich, Zurich, 8000, Switzerland
| | - Robert Riener
- Institute for Rehabilitation and Performance Technology, Division of Mechanical Engineering, Department of Engineering and Information Technology, Bern University of Applied Sciences, Pestalozzistrasse 20, Burgdorf, 3400, Switzerland.,Sensory Motor Systems Lab, Department of Health Sciences and Technology, ETH Zurich, Zurich, 8000, Switzerland
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Zheng Y, Shin H, Hu X. Muscle Fatigue Post-stroke Elicited From Kilohertz-Frequency Subthreshold Nerve Stimulation. Front Neurol 2018; 9:1061. [PMID: 30564190 PMCID: PMC6288233 DOI: 10.3389/fneur.2018.01061] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 11/21/2018] [Indexed: 11/13/2022] Open
Abstract
Purpose: Rapid muscle fatigue limits clinical applications of functional electrical stimulation (FES) for individuals with motor impairments. This study aimed to characterize the sustainability of muscle force elicited with a novel transcutaneous nerve stimulation technique. Method: A hemiplegic chronic stroke survivor was recruited in this case study. Clustered subthreshold pulses of 60-μs with kilohertz (12.5 kHz) carrier frequency (high-frequency mode, HF) were delivered transcutaneously to the proximal segment of the median/ulnar nerve bundles to evaluate the finger flexor muscle fatigue on both sides of the stroke survivor. Conventional nerve stimulation technique with 600-μs pulses at 30 Hz (low-frequency mode, LF) served as the control condition. Fatigue was evoked by intermittently delivering 3-s stimulation trains with 1-s resting. For fair comparison, initial contraction forces (approximately 30% of the maximal voluntary contraction) were matched between the HF and LF modes. Muscle fatigue was evaluated through elicited finger flexion forces (amplitude and fluctuation) and muscle activation patterns quantified by high-density electromyography (EMG). Result: Compared with those from the LF stimuli, the elicited forces declined more slowly, and the force plateau was higher under the HF stimulation for both the affected and contralateral sides, resulting in a more sustainable force output at higher levels. Meanwhile, the force fluctuation under the HF stimulation increased more slowly, and, thus, was smaller after successive stimulation trains compared with the LF stimuli, indicating a less synchronized activation of muscle fibers. The efficiency of the muscle activation, measured as the force-EMG ratio, was also higher in the HF stimulation mode. Conclusion: Our results indicated that the HF nerve stimulation technique can reduce muscle fatigue in stroke survivors by maintaining a higher efficiency of muscle activations compared with the LF stimulation. The technique can help improve the performance of neurorehabilitation methods based on electrical stimulation, and facilitate the utility of FES in clinical populations.
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Affiliation(s)
- Yang Zheng
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, NC, United States
| | - Henry Shin
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, NC, United States
| | - Xiaogang Hu
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, NC, United States
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Zheng Y, Hu X. Reduced muscle fatigue using kilohertz-frequency subthreshold stimulation of the proximal nerve. J Neural Eng 2018; 15:066010. [DOI: 10.1088/1741-2552/aadecc] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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8
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Thakur AA, Wang X, Garcia-Betancourt MM, Forse RA. Calcium channel blockers and the incidence of breast and prostate cancer: A meta-analysis. J Clin Pharm Ther 2018; 43:519-529. [DOI: 10.1111/jcpt.12673] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Accepted: 02/01/2018] [Indexed: 01/07/2023]
Affiliation(s)
- A. A. Thakur
- Internal Medicine; Danbury Hospital; Western Connecticut Health Network; Danbury CT USA
- Doctor's Hospital at Renaissance Health System; Edinburg TX USA
| | - X. Wang
- Department of Mathematics and Statistics; University of Texas-Rio Grande Valley; Edinburg TX USA
| | - M. M. Garcia-Betancourt
- Department of Academic Medicine; Doctors Hospital at Renaissance Health System; Edinburg TX USA
| | - R. A. Forse
- Doctor's Hospital at Renaissance Health System; Edinburg TX USA
- Doctor’s Hospital at Renaissance Health System Clinical Professor of Surgery; University of Texas-Rio Grande Valley; Edinburg TX USA
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Aksöz EA, Luder MA, Laubacher M, Riener R, Binder-Macleod SA, Hunt KJ. Stochastically modulated inter-pulse intervals to increase the efficiency of functional electrical stimulation cycling. J Rehabil Assist Technol Eng 2018; 5:2055668318767364. [PMID: 31191935 PMCID: PMC6453100 DOI: 10.1177/2055668318767364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 03/07/2018] [Indexed: 11/30/2022] Open
Abstract
Introduction Functional electrical stimulation cycling has various health benefits, but
the mechanical power output and efficiency are very low compared to
volitional muscle activation. Stimulation with variable frequency showed
significantly higher power output values in experiments with a knee
dynamometer. The aim of the present work was to compare stochastic
modulation of inter-pulse interval to constant inter-pulse interval
stimulation during functional electrical stimulation cycling. Methods Seventeen able-bodied subjects participated (n = 17).
Quadriceps and hamstring muscle groups were stimulated with two activation
patterns: P1-constant frequency, P2-stochastic inter-pulse interval. Power
output was measured on functional electrical stimulation ergometer. Results Overall, mean power output with the stochastically modulated pattern P2 was
lower than with P1 (12.57 ± 3.74 W vs. 11.44 ± 3.81 W, P1 vs. P2,
p = 0.022), but no significant differences during the
first 30 s and the last 30 s were observed. Conclusions This study showed that stimulation strategies that use randomized modulation
of inter-pulse intervals can negatively affect power output generation
during functional electrical stimulation cycling. To minimise voluntary
contractions, power measurement and assessment should be focused on the
periods where only the quadriceps are stimulated.
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Affiliation(s)
- E A Aksöz
- Department of Engineering and Information Technology, Division of Mechanical Engineering, Institute for Rehabilitation and Performance Technology, Bern University of Applied Sciences, Burgdorf, Switzerland.,Department of Health Sciences and Technology, Sensory Motor Systems Lab, ETH Zürich, Zürich, Switzerland
| | - M A Luder
- Department of Engineering and Information Technology, Division of Mechanical Engineering, Institute for Rehabilitation and Performance Technology, Bern University of Applied Sciences, Burgdorf, Switzerland
| | - M Laubacher
- Department of Engineering and Information Technology, Division of Mechanical Engineering, Institute for Rehabilitation and Performance Technology, Bern University of Applied Sciences, Burgdorf, Switzerland.,Department of Health Sciences and Technology, Sensory Motor Systems Lab, ETH Zürich, Zürich, Switzerland
| | - R Riener
- Department of Health Sciences and Technology, Sensory Motor Systems Lab, ETH Zürich, Zürich, Switzerland
| | | | - K J Hunt
- Department of Engineering and Information Technology, Division of Mechanical Engineering, Institute for Rehabilitation and Performance Technology, Bern University of Applied Sciences, Burgdorf, Switzerland
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Meng L, Porr B, Macleod CA, Gollee H. A functional electrical stimulation system for human walking inspired by reflexive control principles. Proc Inst Mech Eng H 2017; 231:315-325. [PMID: 28332444 PMCID: PMC5405833 DOI: 10.1177/0954411917693879] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 01/16/2017] [Indexed: 11/24/2022]
Abstract
This study presents an innovative multichannel functional electrical stimulation gait-assist system which employs a well-established purely reflexive control algorithm, previously tested in a series of bipedal walking robots. In these robots, ground contact information was used to activate motors in the legs, generating a gait cycle similar to that of humans. Rather than developing a sophisticated closed-loop functional electrical stimulation control strategy for stepping, we have instead utilised our simple reflexive model where muscle activation is induced through transfer functions which translate sensory signals, predominantly ground contact information, into motor actions. The functionality of the functional electrical stimulation system was tested by analysis of the gait function of seven healthy volunteers during functional electrical stimulation-assisted treadmill walking compared to unassisted walking. The results demonstrated that the system was successful in synchronising muscle activation throughout the gait cycle and was able to promote functional hip and ankle movements. Overall, the study demonstrates the potential of human-inspired robotic systems in the design of assistive devices for bipedal walking.
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Affiliation(s)
- Lin Meng
- Division of Biomedical Engineering, University of Glasgow, Glasgow, UK
- Department of Biomedical Engineering, University of Strathclyde, Glasgow, UK
| | - Bernd Porr
- Division of Biomedical Engineering, University of Glasgow, Glasgow, UK
| | - Catherine A Macleod
- Department of Biomedical Engineering, University of Strathclyde, Glasgow, UK
| | - Henrik Gollee
- Division of Biomedical Engineering, University of Glasgow, Glasgow, UK
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Modeling the effect of tilting, passive leg exercise, and functional electrical stimulation on the human cardiovascular system. Med Biol Eng Comput 2017; 55:1693-1708. [PMID: 28188470 DOI: 10.1007/s11517-017-1628-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 01/27/2017] [Indexed: 01/02/2023]
Abstract
Long periods of bed rest negatively affect the human body organs, notably the cardiovascular system. To avert these negative effects and promote functional recovery in patients dealing with prolonged bed rest, the goal is to mobilize them as early as possible while controlling and stabilizing their cardiovascular system. A robotic tilt table allows early mobilization by modulating body inclination, automated passive leg exercise, and the intensity of functional electrical stimulation applied to leg muscles (inputs). These inputs are used to control the cardiovascular variables heart rate (HR), and systolic and diastolic blood pressures (sBP, dBP) (outputs). To enhance the design of the closed-loop cardiovascular biofeedback controller, we investigated a subject-specific multi-input multi-output (MIMO) black-box model describing the relationship between the inputs and outputs. For identification of the linear part of the system, two popular linear model structures-the autoregressive model with exogenous input and the output error model-are examined and compared. The estimation algorithm is tested in simulation and then used in four study protocols with ten healthy participants to estimate transfer functions of HR, sBP and dBP to the inputs. The results show that only the HR transfer functions to inclination input can explain the variance in the data to a reasonable extent (on average 69.8%). As in the other input types, the responses are nonlinear; the models are either not reliable or explain only a negligible amount of the observed variance. Analysis of both, the nonlinearities and the occasionally occurring zero-crossings, is necessary before designing an appropriate MIMO controller for mobilization of bedridden patients.
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Aksöz EA, Laubacher M, Binder-Macleod S, Hunt KJ. Effect of Stochastic Modulation of Inter-Pulse Interval During Stimulated Isokinetic Leg Extension. Eur J Transl Myol 2016; 26:6160. [PMID: 27990242 PMCID: PMC5128975 DOI: 10.4081/ejtm.2016.6160] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Recumbent cycling exercise achieved by functional electrical stimulation (FES) of the paralyzed leg muscles is effective for cardiopulmonary and musculoskeletal conditioning after spinal cord injury, but its full potential has not yet been realized. Mechanical power output and efficiency is very low and endurance is limited due to early onset of muscle fatigue. The aim of this work was to compare stochastic modulation of the inter-pulse interval (IPI) to constant-frequency stimulation during an isokinetic leg extension task similar to FES-cycling. Seven able-bodied subjects participated: both quadriceps muscles were stimulated (n = 14) with two activation patterns (P1-constant frequency, P2-stochastic IPI). There was significantly higher power output with P2 during the first 30 s (p = 0.0092), the last 30 s (p = 0.018) and overall (p = 0.0057), but there was no overall effect on fatiguability when stimulation frequency was randomly modulated.
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Affiliation(s)
- Efe Anil Aksöz
- Institute for Rehabilitation and Performance Technology, Bern University of Applied Sciences, Burgdorf, Switzerland; Sensory Motor Systems Lab, ETH Zurich, Zürich, Switzerland
| | - Marco Laubacher
- Institute for Rehabilitation and Performance Technology, Bern University of Applied Sciences, Burgdorf, Switzerland; Sensory Motor Systems Lab, ETH Zurich, Zürich, Switzerland
| | | | - Kenneth J Hunt
- Institute for Rehabilitation and Performance Technology, Bern University of Applied Sciences , Burgdorf, Switzerland
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Ibitoye MO, Hamzaid NA, Hasnan N, Abdul Wahab AK, Davis GM. Strategies for Rapid Muscle Fatigue Reduction during FES Exercise in Individuals with Spinal Cord Injury: A Systematic Review. PLoS One 2016; 11:e0149024. [PMID: 26859296 PMCID: PMC4747522 DOI: 10.1371/journal.pone.0149024] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Background Rapid muscle fatigue during functional electrical stimulation (FES)-evoked muscle contractions in individuals with spinal cord injury (SCI) is a significant limitation to attaining health benefits of FES-exercise. Delaying the onset of muscle fatigue is often cited as an important goal linked to FES clinical efficacy. Although the basic concept of fatigue-resistance has a long history, recent advances in biomedical engineering, physiotherapy and clinical exercise science have achieved improved clinical benefits, especially for reducing muscle fatigue during FES-exercise. This review evaluated the methodological quality of strategies underlying muscle fatigue-resistance that have been used to optimize FES therapeutic approaches. The review also sought to synthesize the effectiveness of these strategies for persons with SCI in order to establish their functional impacts and clinical relevance. Methods Published scientific literature pertaining to the reduction of FES-induced muscle fatigue was identified through searches of the following databases: Science Direct, Medline, IEEE Xplore, SpringerLink, PubMed and Nature, from the earliest returned record until June 2015. Titles and abstracts were screened to obtain 35 studies that met the inclusion criteria for this systematic review. Results Following the evaluation of methodological quality (mean (SD), 50 (6) %) of the reviewed studies using the Downs and Black scale, the largest treatment effects reported to reduce muscle fatigue mainly investigated isometric contractions of limited functional and clinical relevance (n = 28). Some investigations (n = 13) lacked randomisation, while others were characterised by small sample sizes with low statistical power. Nevertheless, the clinical significance of emerging trends to improve fatigue-resistance during FES included (i) optimizing electrode positioning, (ii) fine-tuning of stimulation patterns and other FES parameters, (iii) adjustments to the mode and frequency of exercise training, and (iv) biofeedback-assisted FES-exercise to promote selective recruitment of fatigue-resistant motor units. Conclusion Although the need for further in-depth clinical trials (especially RCTs) was clearly warranted to establish external validity of outcomes, current evidence was sufficient to support the validity of certain techniques for rapid fatigue-reduction in order to promote FES therapy as an integral part of SCI rehabilitation. It is anticipated that this information will be valuable to clinicians and other allied health professionals administering FES as a treatment option in rehabilitation and aid the development of effective rehabilitation interventions.
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Affiliation(s)
- Morufu Olusola Ibitoye
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia
- Department of Biomedical Engineering, Faculty of Engineering and Technology, University of Ilorin, Ilorin, Nigeria
| | - Nur Azah Hamzaid
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia
- * E-mail:
| | - Nazirah Hasnan
- Department of Rehabilitation Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Ahmad Khairi Abdul Wahab
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia
| | - Glen M. Davis
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia
- Clinical Exercise and Rehabilitation Unit, Discipline of Exercise and Sport Sciences, Faculty of Health Sciences, The University of Sydney, Sydney, Australia
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Downey RJ, Cheng TH, Bellman MJ, Dixon WE. Closed-Loop Asynchronous Neuromuscular Electrical Stimulation Prolongs Functional Movements in the Lower Body. IEEE Trans Neural Syst Rehabil Eng 2015; 23:1117-27. [PMID: 25935038 DOI: 10.1109/tnsre.2015.2427658] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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15
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Low-intensity functional electrical stimulation can increase multidirectional trunk stiffness in able-bodied individuals during sitting. Med Eng Phys 2015; 37:777-82. [DOI: 10.1016/j.medengphy.2015.05.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 04/19/2015] [Accepted: 05/09/2015] [Indexed: 11/21/2022]
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Sayenko DG, Nguyen R, Hirabayashi T, Popovic MR, Masani K. Method to Reduce Muscle Fatigue During Transcutaneous Neuromuscular Electrical Stimulation in Major Knee and Ankle Muscle Groups. Neurorehabil Neural Repair 2014; 29:722-33. [PMID: 25549655 DOI: 10.1177/1545968314565463] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND A critical limitation with transcutaneous neuromuscular electrical stimulation as a rehabilitative approach is the rapid onset of muscle fatigue during repeated contractions. We have developed a method called spatially distributed sequential stimulation (SDSS) to reduce muscle fatigue by distributing the center of electrical field over a wide area within a single stimulation site, using an array of surface electrodes. OBJECTIVE To extend the previous findings and to prove feasibility of the method by exploring the fatigue-reducing ability of SDSS for lower limb muscle groups in the able-bodied population, as well as in individuals with spinal cord injury (SCI). METHODS SDSS was delivered through 4 active electrodes applied to the knee extensors and flexors, plantarflexors, and dorsiflexors, sending a stimulation pulse to each electrode one after another with 90° phase shift between successive electrodes. Isometric ankle torque was measured during fatiguing stimulations using SDSS and conventional single active electrode stimulation lasting 2 minutes. RESULTS We demonstrated greater fatigue-reducing ability of SDSS compared with the conventional protocol, as revealed by larger values of fatigue index and/or torque peak mean in all muscles except knee flexors of able-bodied individuals, and in all muscles tested in individuals with SCI. CONCLUSIONS Our study has revealed improvements in fatigue tolerance during transcutaneous neuromuscular electrical stimulation using SDSS, a stimulation strategy that alternates activation of subcompartments of muscles. The SDSS protocol can provide greater stimulation times with less decrement in mechanical output compared with the conventional protocol.
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Affiliation(s)
| | - Robert Nguyen
- Automatic Control Laboratory, ETH Zurich, Zurich, Switzerland
| | - Tomoyo Hirabayashi
- Toronto Rehabilitation Institute-University Health Network, Toronto, Ontario, Canada
| | - Milos R Popovic
- Toronto Rehabilitation Institute-University Health Network, Toronto, Ontario, Canada University of Toronto, Toronto, Ontario, Canada
| | - Kei Masani
- Toronto Rehabilitation Institute-University Health Network, Toronto, Ontario, Canada University of Toronto, Toronto, Ontario, Canada
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Grahn PJ, Lee KH, Kasasbeh A, Mallory GW, Hachmann JT, Dube JR, Kimble CJ, Lobel DA, Bieber A, Jeong JH, Bennet KE, Lujan JL. Wireless control of intraspinal microstimulation in a rodent model of paralysis. J Neurosurg 2014; 123:232-242. [PMID: 25479124 DOI: 10.3171/2014.10.jns132370] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
OBJECT Despite a promising outlook, existing intraspinal microstimulation (ISMS) techniques for restoring functional motor control after spinal cord injury are not yet suitable for use outside a controlled laboratory environment. Thus, successful application of ISMS therapy in humans will require the use of versatile chronic neurostimulation systems. The objective of this study was to establish proof of principle for wireless control of ISMS to evoke controlled motor function in a rodent model of complete spinal cord injury. METHODS The lumbar spinal cord in each of 17 fully anesthetized Sprague-Dawley rats was stimulated via ISMS electrodes to evoke hindlimb function. Nine subjects underwent complete surgical transection of the spinal cord at the T-4 level 7 days before stimulation. Targeting for both groups (spinalized and control) was performed under visual inspection via dorsal spinal cord landmarks such as the dorsal root entry zone and the dorsal median fissure. Teflon-insulated stimulating platinum-iridium microwire electrodes (50 μm in diameter, with a 30- to 60-μm exposed tip) were implanted within the ventral gray matter to an approximate depth of 1.8 mm. Electrode implantation was performed using a free-hand delivery technique (n = 12) or a Kopf spinal frame system (n = 5) to compare the efficacy of these 2 commonly used targeting techniques. Stimulation was controlled remotely using a wireless neurostimulation control system. Hindlimb movements evoked by stimulation were tracked via kinematic markers placed on the hips, knees, ankles, and paws. Postmortem fixation and staining of the spinal cord tissue were conducted to determine the final positions of the stimulating electrodes within the spinal cord tissue. RESULTS The results show that wireless ISMS was capable of evoking controlled and sustained activation of ankle, knee, and hip muscles in 90% of the spinalized rats (n = 9) and 100% of the healthy control rats (n = 8). No functional differences between movements evoked by either of the 2 targeting techniques were revealed. However, frame-based targeting required fewer electrode penetrations to evoke target movements. CONCLUSIONS Clinical restoration of functional movement via ISMS remains a distant goal. However, the technology presented herein represents the first step toward restoring functional independence for individuals with chronic spinal cord injury.
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Affiliation(s)
- Peter J Grahn
- Mayo Graduate School, Mayo Clinic, Rochester, Minnesota
| | - Kendall H Lee
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Aimen Kasasbeh
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota
| | - Grant W Mallory
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota
| | - Jan T Hachmann
- Mayo Graduate School, Mayo Clinic, Rochester, Minnesota.,Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota
| | - John R Dube
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota
| | | | - Darlene A Lobel
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota
| | - Allan Bieber
- Mayo Graduate School, Mayo Clinic, Rochester, Minnesota.,Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota.,Department of Neurology, Mayo Clinic, Rochester, Minnesota
| | - Ju Ho Jeong
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota
| | - Kevin E Bennet
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota.,Division of Engineering, Mayo Clinic, Rochester, Minnesota
| | - J Luis Lujan
- Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
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Mechanomyographic parameter extraction methods: an appraisal for clinical applications. SENSORS 2014; 14:22940-70. [PMID: 25479326 PMCID: PMC4299047 DOI: 10.3390/s141222940] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 10/28/2014] [Accepted: 11/04/2014] [Indexed: 11/16/2022]
Abstract
The research conducted in the last three decades has collectively demonstrated that the skeletal muscle performance can be alternatively assessed by mechanomyographic signal (MMG) parameters. Indices of muscle performance, not limited to force, power, work, endurance and the related physiological processes underlying muscle activities during contraction have been evaluated in the light of the signal features. As a non-stationary signal that reflects several distinctive patterns of muscle actions, the illustrations obtained from the literature support the reliability of MMG in the analysis of muscles under voluntary and stimulus evoked contractions. An appraisal of the standard practice including the measurement theories of the methods used to extract parameters of the signal is vital to the application of the signal during experimental and clinical practices, especially in areas where electromyograms are contraindicated or have limited application. As we highlight the underpinning technical guidelines and domains where each method is well-suited, the limitations of the methods are also presented to position the state of the art in MMG parameters extraction, thus providing the theoretical framework for improvement on the current practices to widen the opportunity for new insights and discoveries. Since the signal modality has not been widely deployed due partly to the limited information extractable from the signals when compared with other classical techniques used to assess muscle performance, this survey is particularly relevant to the projected future of MMG applications in the realm of musculoskeletal assessments and in the real time detection of muscle activity.
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Kafri M, Laufer Y. Therapeutic effects of functional electrical stimulation on gait in individuals post-stroke. Ann Biomed Eng 2014; 43:451-66. [PMID: 25316590 DOI: 10.1007/s10439-014-1148-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 09/30/2014] [Indexed: 10/24/2022]
Abstract
Functional electrical stimulation (FES) to lower extremity (LE) muscles is used by individuals post-stroke as an alternative to mechanical orthotic devices during gait or as a training modality during rehabilitation. Technological developments which improve the feasibility, accessibility and effectiveness of FES systems as orthotic and training devices, highlight the potential of FES for rehabilitating LE function in individuals post-stroke. This study presents a systematic review of the carryover effects of LE FES to motor performance when stimulation is not applied (therapeutic effects) in subjects post-stroke. A description of advances in FES technologies, with an emphasis on systems designed to promote LE function is included, and mechanisms that may be associated with the observed therapeutic effects are discussed. Eligible studies were reviewed for methodological quality, population, intervention and outcome characteristics. Therapeutic effects of FES were consistently demonstrated at the body function and activity levels when it was used as a training modality. Compared to matched treatments that did not incorporate FES, no definite conclusions can be drawn regarding the superiority of FES. When FES was used as an alternative to an orthotic device, it had no superior therapeutic effects at the activity level, yet patients still seemed to prefer it.
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Affiliation(s)
- Michal Kafri
- Department of Physical Therapy Faculty of Social Welfare & Health Sciences, University of Haifa, Mount Carmel, Haifa, 3498838, Israel,
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20
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Sayenko DG, Nguyen R, Popovic MR, Masani K. Reducing muscle fatigue during transcutaneous neuromuscular electrical stimulation by spatially and sequentially distributing electrical stimulation sources. Eur J Appl Physiol 2014; 114:793-804. [PMID: 24390690 PMCID: PMC3950614 DOI: 10.1007/s00421-013-2807-4] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 12/17/2013] [Indexed: 12/01/2022]
Abstract
Purpose A critical limitation with transcutaneous neuromuscular electrical stimulation is the rapid onset of muscle fatigue. We have previously demonstrated that spatially distributed sequential stimulation (SDSS) shows a drastically greater fatigue-reducing ability compared to a single active electrode stimulation (SES). The purposes of this study were to investigate (1) the fatigue-reducing ability of SDSS in more detail focusing on the muscle contractile properties and (2) the mechanism of this effect using array-arranged electromyogram (EMG). Methods SDSS was delivered through four active electrodes applied to the plantarflexors, sending a stimulation pulse to each electrode one after another with 90° phase shift between successive electrodes. In the first experiment, the amount of exerted ankle torque and the muscle contractile properties were investigated during a 3 min fatiguing stimulation. In the second experiment, muscle twitch potentials with SDSS and SES stimulation electrode setups were compared using the array-arranged EMG. Results The results demonstrated negligible torque decay during SDSS in contrast to considerable torque decay during SES. Moreover, small changes in the muscle contractile properties during the fatiguing stimulation using SDSS were observed, while slowing of muscle contraction and relaxation was observed during SES. Further, the amplitude of the M-waves at each muscle portion was dependent on the location of the stimulation electrodes during SDSS. Conclusion We conclude that SDSS is more effective in reducing muscle fatigue compared to SES, and the reason is that different sets of muscle fibers are activated alternatively by different electrodes.
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Affiliation(s)
- Dimitry G Sayenko
- Department of Neurological Surgery, University of Louisville Frazier Rehab Institute, 220 Abraham Flexner Way, Ste. 1506, Louisville, KY, 40202, USA
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Lynch CL, Popovic MR. A comparison of closed-loop control algorithms for regulating electrically stimulated knee movements in individuals with spinal cord injury. IEEE Trans Neural Syst Rehabil Eng 2012; 20:539-48. [PMID: 22772375 DOI: 10.1109/tnsre.2012.2185065] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Functional electrical stimulation (FES) is the most commonly used technology for improving motor function in individuals who have spinal cord injury. Despite the wide range of FES applications reported in the literature, few electrical stimulation systems that can generate meaningful functional outcomes are currently available for use outside research laboratories. We tested proportional-integral-derivative, gain scheduling, and sliding mode control closed-loop control algorithms in a simulation of electrically induced knee extension against gravity to uncover some of the reasons why closed-loop control is not being more widely used in real-world FES systems. We also subjected the simulated FES system to muscle fatigue, muscle spasms, and the effects of muscle retraining. All of the controllers exhibited significantly degraded performance when these real-world nonlinear effects were included in the simulation. Moreover, all of the controllers were sensitive to variation in the parameters of the muscle recruitment function, which are subject to change during real-world FES use. We suggest several ways to improve the performance of closed-loop control algorithms for use in FES applications. We believe that closed-loop controllers have an important place in future FES applications, but the performance of these algorithms must be greatly improved before they can be implemented in real-world systems.
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Affiliation(s)
- Cheryl L Lynch
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada.
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Chen CF, Chen WS, Chou LW, Chang YJ, Chen SC, Kuo TS, Lai JS. Pulse energy as a reliable reference for twitch forces induced by transcutaneous neuromuscular electrical stimulation. IEEE Trans Neural Syst Rehabil Eng 2012; 20:574-83. [PMID: 22481833 DOI: 10.1109/tnsre.2012.2188305] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Voltage-controlled neuromuscular electrical stimulation has been considered to be safer in noninvasive applications notwithstanding the fact that voltage-controlled devices purportedly generate forces less predictable than their current-controlled equivalents. This prompted us to evaluate relevant electrical parameters to determine whether forces induced by voltage-controlled stimuli were able to match to those induced by current-controlled ones, which tend to evoke forces that were more predictable. Force magnitudes corresponding to current- and voltage-controlled stimuli were aligned with respect to electric charge (equivalent to average current intensity) and electrical energy (equivalent to average power) of the same stimulation pulse to determine which provided a better coherence. Consistency of forces evaluated with energy was significantly (p < 0.001) better than that evaluated with electric charges, suggesting that electrically stimulated forces can be reliably predicted by monitoring the energy parameter of stimulation pulses. The above results appear to show that electrode-tissue impedance, a factor that makes charge and energy evaluations different, redefined the actual effects of current intensities in generating favorable results. Accordingly, novel schemes that track the energy (or average power) of a stimulation pulse may be used as a reliable benchmark to associate mechanical (force) and electrical (stimulation pulse) characteristics in transcutaneous applications of electrical stimulation.
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Affiliation(s)
- Chiun-Fan Chen
- Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan
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Motor unit recruitment during neuromuscular electrical stimulation: a critical appraisal. Eur J Appl Physiol 2011; 111:2399-407. [PMID: 21870119 DOI: 10.1007/s00421-011-2128-4] [Citation(s) in RCA: 213] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Accepted: 08/12/2011] [Indexed: 10/17/2022]
Abstract
Neuromuscular electrical stimulation (NMES) is commonly used in clinical settings to activate skeletal muscle in an effort to mimic voluntary contractions and enhance the rehabilitation of human skeletal muscles. It is also used as a tool in research to assess muscle performance and/or neuromuscular activation levels. However, there are fundamental differences between voluntary- and artificial-activation of motor units that need to be appreciated before NMES protocol design can be most effective. The unique effects of NMES have been attributed to several mechanisms, most notably, a reversal of the voluntary recruitment pattern that is known to occur during voluntary muscle contractions. This review outlines the assertion that electrical stimulation recruits motor units in a nonselective, spatially fixed, and temporally synchronous pattern. Additionally, it synthesizes the evidence that supports the contention that this recruitment pattern contributes to increased muscle fatigue when compared with voluntary actions and provides some commentary on the parameters of electrical stimulation as well as emerging technologies being developed to facilitate NMES implementation. A greater understanding of how electrical stimulation recruits motor units, as well as the benefits and limitations of its use, is highly relevant when using this tool for testing and training in rehabilitation, exercise, and/or research.
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Nguyen R, Masani K, Micera S, Morari M, Popovic MR. Spatially distributed sequential stimulation reduces fatigue in paralyzed triceps surae muscles: a case study. Artif Organs 2011; 35:1174-80. [PMID: 21501192 DOI: 10.1111/j.1525-1594.2010.01195.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Functional electrical stimulation (FES) is limited by the rapid onset of muscle fatigue caused by localized nerve excitation repeatedly activating only a subset of motor units. The purpose of this study was to investigate reducing fatigue by sequentially changing, pulse by pulse, the area of stimulation using multiple surface electrodes that cover the same area as one electrode during conventional stimulation. Paralyzed triceps surae muscles of an individual with complete spinal cord injury were stimulated, via the tibial nerve, through four active electrodes using spatially distributed sequential stimulation (SDSS) that was delivered by sending a stimulation pulse to each electrode one after another with 90° phase shift between successive electrodes. For comparison, single electrode stimulation was delivered through one active electrode. For both modes of stimulation, the resultant frequency to the muscle as a whole was 40 Hz. Isometric ankle torque was measured during fatiguing stimulations lasting 2 min. Each mode of stimulation was delivered a total of six times over 12 separate days. Three fatigue measures were used for comparison: fatigue index (final torque normalized to maximum torque), fatigue time (time for torque to drop by 3 dB), and torque-time integral (over the entire trial). The measures were all higher during SDSS (P < 0.001), by 234, 280, and 171%, respectively. The results are an encouraging first step toward addressing muscle fatigue, which is one of the greatest problems for FES.
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Affiliation(s)
- Robert Nguyen
- Automatic Control Laboratory, ETH Zurich, Switzerland
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25
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Al-Mulla MR, Sepulveda F, Colley M. A review of non-invasive techniques to detect and predict localised muscle fatigue. SENSORS (BASEL, SWITZERLAND) 2011; 11:3545-94. [PMID: 22163810 PMCID: PMC3231314 DOI: 10.3390/s110403545] [Citation(s) in RCA: 167] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Revised: 03/01/2011] [Accepted: 03/21/2011] [Indexed: 11/16/2022]
Abstract
Muscle fatigue is an established area of research and various types of muscle fatigue have been investigated in order to fully understand the condition. This paper gives an overview of the various non-invasive techniques available for use in automated fatigue detection, such as mechanomyography, electromyography, near-infrared spectroscopy and ultrasound for both isometric and non-isometric contractions. Various signal analysis methods are compared by illustrating their applicability in real-time settings. This paper will be of interest to researchers who wish to select the most appropriate methodology for research on muscle fatigue detection or prediction, or for the development of devices that can be used in, e.g., sports scenarios to improve performance or prevent injury. To date, research on localised muscle fatigue focuses mainly on the clinical side. There is very little research carried out on the implementation of detecting/predicting fatigue using an autonomous system, although recent research on automating the process of localised muscle fatigue detection/prediction shows promising results.
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Affiliation(s)
- Mohamed R. Al-Mulla
- School of Computer Science and Electronic Engineering, University of Essex, Colchester, UK; E-Mails: (F.S.); (M.C.)
| | - Francisco Sepulveda
- School of Computer Science and Electronic Engineering, University of Essex, Colchester, UK; E-Mails: (F.S.); (M.C.)
| | - Martin Colley
- School of Computer Science and Electronic Engineering, University of Essex, Colchester, UK; E-Mails: (F.S.); (M.C.)
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Lynch CL, Graham GM, Popovic MR. Including nonideal behavior in simulations of functional electrical stimulation applications. Artif Organs 2011; 35:267-9. [PMID: 21401672 DOI: 10.1111/j.1525-1594.2011.01218.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Simulations of functional electrical stimulation (FES) systems are usually based on the typical or ideal stimulated muscle response, which may result in an overly optimistic prediction of the FES system's performance in real-world applications. We have developed a Simulink block that allows actual nonideal behavior of electrically stimulated muscles to be incorporated into existing FES simulations. This block is based on data collected from complete spinal cord injuries (SCI) subjects, and it modifies the nominal stimulated muscle response to reflect undesirable behavior seen in real-world FES applications, including spasms, tremors, and fatigue. The severity of each type of undesirable behavior can be specified by the user. In this paper, we discuss the design of the block and also present an example of how the block can be used to more accurately assess the probable real-world performance of FES systems prior to testing with SCI subjects.
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Affiliation(s)
- Cheryl L Lynch
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada.
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Malesević NM, Popović LZ, Schwirtlich L, Popović DB. Distributed low-frequency functional electrical stimulation delays muscle fatigue compared to conventional stimulation. Muscle Nerve 2010; 42:556-62. [PMID: 20665516 DOI: 10.1002/mus.21736] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We present a low-frequency stimulation method via multi-pad electrodes for delaying muscle fatigue. We compared two protocols for muscle activation of the quadriceps in paraplegics. One protocol involved a large cathode at 30 HZ (HPR, high pulse-rate), and the other involved four smaller cathodes at 16 HZ (LPR, low pulse-rate). The treatment included 30-min daily sessions for 20 days. One leg was treated with the HPR protocol and the other with the LPR protocol. Knee-joint torque was measured before and after therapy to assess the time interval before the knee-joint torque decreased to 70% of the initial value. The HPR therapy provided greater increases in muscle endurance and force in prolonged training. Yet the LPR stimulation produced less muscle fatigue compared to the HPR stimulation. The results suggest that HPR is the favored protocol for training, and LPR is better suited for prolonged stimulation.
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Affiliation(s)
- Nebojsa M Malesević
- Faculty of Electrical Engineering, University of Belgrade, Bulevar kralja Aleksandra 73, 11000 Belgrade, Serbia.
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Kaczmarek P, Huber J, Lisiński P, Witkowska A, Kasiński A. Investigation of the Relationship Between Stimulus Parameters and a Human Muscle Contraction Force During Stimulation of the Gastrocnemius Muscle. Artif Organs 2010; 34:126-35. [DOI: 10.1111/j.1525-1594.2009.00759.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Freeman CT, Hughes AM, Burridge JH, Chappell PH, Lewin PL, Rogers E. A model of the upper extremity using FES for stroke rehabilitation. J Biomech Eng 2009; 131:031011. [PMID: 19154070 DOI: 10.1115/1.3005332] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A model of the upper extremity is developed in which the forearm is constrained to lie in a horizontal plane and electrical stimulation is applied to the triceps muscle. Identification procedures are described to estimate the unknown parameters using tests that can be performed in a short period of time. Examples of identified parameters obtained experimentally are presented for both stroke patients and unimpaired subjects. A discussion concerning the identification's repeatability, together with results confirming the accuracy of the overall representation, is given. The model has been used during clinical trials in which electrical stimulation is applied to the triceps muscle of a number of stroke patients for the purpose of improving both their performance at reaching tasks and their level of voluntary control over their impaired arm. Its purpose in this context is threefold: Firstly, changes occurring in the levels of stiffness and spasticity in each subject's arm can be monitored by comparing frictional components of models identified at different times during treatment. Secondly, the model is used to calculate the moments applied during tracking tasks that are due to a patient's voluntary effort, and it therefore constitutes a useful tool with which to analyze their performance. Thirdly, the model is used to derive the advanced controllers that govern the level of stimulation applied to subjects over the course of the treatment. Details are provided to show how the model is applied in each case, and sample results are shown.
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Affiliation(s)
- Chris T Freeman
- School of Electronics and Computer Science, University of Southampton, Highfield, Southampton SO17 1BJ, UK
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Popovic LZ, Malesevic NM. Muscle fatigue of quadriceps in paraplegics: comparison between single vs. multi-pad electrode surface stimulation. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2009; 2009:6785-6788. [PMID: 19964709 DOI: 10.1109/iembs.2009.5333983] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We hypothesize that the asynchronous low frequency stimulation of pads within multi-pad electrode will be less fatiguing compared to the conventional stimulation (two single pad electrodes) when generating comparable large forces of paralyzed human muscles. The experiments to verify the hypothesis were conducted on quadriceps of six individuals with chronic spinal cord injury (ASIA score A) who had not participated in any electrical stimulation program. The following stimulation protocols were compared: stimulation with a self adhesive 7 cm x 10 cm Pals Platinum cathode positioned over the top of the quadriceps (f = 40 Hz), and four oval 4 cm x 6 cm cathodes positioned over the proximal upper leg (f = 16 Hz). The anode in both cases was the 7 cm x 10 cm Pals Platinum electrode positioned over the distal part of the quadriceps. We measured the knee joint torque vs. time with a custom made apparatus, and estimated the interval before the knee joint torque decreased to 70% of the maximum. Mean fatigue interval increase for the four-pad stimulation protocol vs. single-pad stimulation protocol was 153.18%. This suggests that the use of multi-pad electrodes is favorable in cases where a prolonged stimulation of muscles is required.
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Affiliation(s)
- Lana Z Popovic
- Faculty of Electrical Engineering, University of Belgrade, Serbia and Fatronik Serbia, Belgrade, Serbia
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Amer MB, Ammary S, Al-Ebbini L, Awwad M, Qtait Y. Novel design of multichannel electrotherapeutic system. J Med Eng Technol 2009; 33:394-402. [DOI: 10.1080/03091900902746713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Thrasher TA, Popovic MR. Functional electrical stimulation of walking: function, exercise and rehabilitation. ACTA ACUST UNITED AC 2008; 51:452-60. [PMID: 18602712 DOI: 10.1016/j.annrmp.2008.05.006] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2008] [Accepted: 05/26/2008] [Indexed: 10/21/2022]
Abstract
For nearly half a century, functional electrical stimulation (FES) has been used to restore walking for people with paralysis and muscle weakness due to stroke and spinal cord injury. The first applications of the technology were intended to permanently replace lost neuromuscular function. Later, FES-assisted walking was found to have therapeutic benefits that include increased muscle strength, cardiovascular fitness and improved gait function that could be maintained after use of FES was terminated. In this review, we examine some of the major FES-assisted walking systems that have been developed for experimental and commercial purposes over the last four and a half decades, including foot drop stimulators, multichannel stimulators and hybrid orthotic systems.
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Affiliation(s)
- T A Thrasher
- Department of Health and Human Performance, Garrison Room 104, University of Houston, 3855, Holman Street, Houston, TX 77204-6015, USA.
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Doucet BM, Griffin L. Maximal versus submaximal intensity stimulation with variable patterns. Muscle Nerve 2008; 37:770-7. [DOI: 10.1002/mus.20992] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Indurthy M, Griffin L. Effect of random interpulse interval modulation on neuromuscular fatigue. Muscle Nerve 2007; 36:807-15. [PMID: 17724736 DOI: 10.1002/mus.20882] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Neuromuscular endurance during electrical stimulation may be enhanced if naturally occurring motor unit firing patterns are used. Variability in the interpulse interval (IPI) distribution may enable brief periods of rest and optimization of force output. Nine individuals participated in three 3-minute fatigue protocols of the thenar muscles elicited by supramaximal stimulation of the median nerve. All protocols consisted of a mean IPI of 33.3 ms and differed only in the type of IPI modulation, which was constant (0%), random (+/-20%), or ramped from 0% to +/-20%. M-wave amplitude declined following all protocols and the reduction was smallest following the ramp protocol. There was no significant difference among the starting or final forces or between the overall force-time integrals for the three protocols. Thus, IPI variability did not improve endurance time during electrical stimulation and the M-wave amplitude was not a reliable indicator of muscle force output.
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Affiliation(s)
- Maritha Indurthy
- Department of Mechanical Engineering, University of Texas at Austin, Austin, Texas, USA
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