A Non-Linear Control Method to Compensate for Muscle Fatigue during Neuromuscular Electrical Stimulation

BackgroundNeuromuscular electrical stimulation (NMES) can facilitate the recovery of quadriceps muscle strength after total knee arthroplasty (TKA), yet the optimal intensity (dosage) of NMES and its effect on strength after TKA have yet to be determined.ObjectiveThe primary objective of this study was to determine whether the intensity of NMES application was related to the recovery of quadriceps muscle strength early after TKA. A secondary objective was to quantify quadriceps muscle fatigue and activation immediately after NMES to guide decisions about the timing of NMES during rehabilitation sessions.DesignThis study was an observational experimental investigation.MethodsData were collected from 30 people who were 50 to 85 years of age and who received NMES after TKA. These people participated in a randomized controlled trial in which they received either standard rehabilitation or standard rehabilitation plus NMES to the quadriceps muscle to mitigate strength loss. For the NMES intervention group, NMES was applied 2 times per day at the maximal tolerable intensity for 15 contractions beginning 48 hours after surgery over the first 6 weeks after TKA. Neuromuscular electrical stimulation training intensity and quadriceps muscle strength and activation were assessed before surgery and 3.5 and 6.5 weeks after TKA.ResultsAt 3.5 weeks, there was a significant association between NMES training intensity and a change in quadriceps muscle strength (R2=.68) and activation (R2=.22). At 6.5 weeks, NMES training intensity was related to a change in strength (R2=.25) but not to a change in activation (R2=.00). Furthermore, quadriceps muscle fatigue occurred during NMES sessions at 3.5 and 6.5 weeks, whereas quadriceps muscle activation did not change.LimitationsSome participants reached the maximal stimulator output during at least 1 treatment session and might have tolerated more stimulation.ConclusionsHigher NMES training intensities were associated with greater quadriceps muscle strength and activation after TKA.

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Muscle Fatigue During Neuromuscular Electrical Stimulation is Dependent on Training: A Basis for Microgravity Musculoskeletal Countermeasure Design

ASCEND 2020 ◽

10.2514/6.2020-4010 ◽

2020 ◽

Author(s):

Thomas J. Abitante ◽

Seward B. Rutkove ◽

Kevin R. Duda ◽

Dava J. Newman

Keyword(s):

Electrical Stimulation ◽

Muscle Fatigue ◽

Neuromuscular Electrical Stimulation

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Method to Reduce Muscle Fatigue During Transcutaneous Neuromuscular Electrical Stimulation in Major Knee and Ankle Muscle Groups

Neurorehabilitation and Neural Repair ◽

10.1177/1545968314565463 ◽

2014 ◽

Vol 29 (8) ◽

pp. 722-733 ◽

Cited By ~ 14

Author(s):

Dimitry G. Sayenko ◽

Robert Nguyen ◽

Tomoyo Hirabayashi ◽

Milos R. Popovic ◽

Kei Masani

Keyword(s):

Electrical Stimulation ◽

Muscle Fatigue ◽

Neuromuscular Electrical Stimulation ◽

Ankle Muscle ◽

Muscle Groups

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Wide-pulse-high-frequency neuromuscular stimulation of triceps surae induces greater muscle fatigue compared with conventional stimulation

Journal of Applied Physiology ◽

10.1152/japplphysiol.01015.2013 ◽

2014 ◽

Vol 116 (10) ◽

pp. 1281-1289 ◽

Cited By ~ 23

Author(s):

Daria Neyroud ◽

David Dodd ◽

Julien Gondin ◽

Nicola A. Maffiuletti ◽

Bengt Kayser ◽

...

Keyword(s):

Electrical Stimulation ◽

Muscle Fatigue ◽

Motor Unit ◽

High Frequency ◽

Neuromuscular Electrical Stimulation ◽

Triceps Surae ◽

Voluntary Activation ◽

Activation Level ◽

Paired Stimulation ◽

Voluntary Activation Level

We compared the extent and origin of muscle fatigue induced by short-pulse-low-frequency [conventional (CONV)] and wide-pulse-high-frequency (WPHF) neuromuscular electrical stimulation. We expected CONV contractions to mainly originate from depolarization of axonal terminal branches (spatially determined muscle fiber recruitment) and WPHF contractions to be partly produced via a central pathway (motor unit recruitment according to size principle). Greater neuromuscular fatigue was, therefore, expected following CONV compared with WPHF. Fourteen healthy subjects underwent 20 WPHF (1 ms-100 Hz) and CONV (50 μs-25 Hz) evoked isometric triceps surae contractions (work/rest periods 20:40 s) at an initial target of 10% of maximal voluntary contraction (MVC) force. Force-time integral of the 20 evoked contractions (FTI) was used as main index of muscle fatigue; MVC force loss was also quantified. Central and peripheral fatigue were assessed by voluntary activation level and paired stimulation amplitudes, respectively. FTI in WPHF was significantly lower than in CONV (21,717 ± 11,541 vs. 37,958 ± 9,898 N·s P<0,001). The reductions in MVC force (WPHF: −7.0 ± 2.7%; CONV: −6.2 ± 2.5%; P < 0.01) and paired stimulation amplitude (WPHF: −8.0 ± 4.0%; CONV: −7.4 ± 6.1%; P < 0.001) were similar between conditions, whereas no change was observed for voluntary activation level ( P > 0.05). Overall, our results showed a different motor unit recruitment pattern between the two neuromuscular electrical stimulation modalities with a lower FTI indicating greater muscle fatigue for WPHF, possibly limiting the presumed benefits for rehabilitation programs.

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Performance Analysis of Controller Design for DC-DC Buck Converter Using Linear and Non Linear Technique

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.719-720.417 ◽

2015 ◽

Vol 719-720 ◽

pp. 417-425 ◽

Cited By ~ 1

Author(s):

Husan Ali ◽

Xian Cheng Zheng ◽

Shahbaz Khan ◽

Waseem Abbas ◽

Dawar Awan

Keyword(s):

Output Voltage ◽

Control Method ◽

Controller Design ◽

Sliding Mode ◽

Input Voltage ◽

Buck Converter ◽

Linear Control ◽

Control Technique ◽

Control Techniques ◽

Non Linear

The switched mode dc-dc converters are some of the most widely used power electronics circuits because of high conversion efficiency and flexible output voltage. Many methods have been developed for the control of dc-dc converters. This paper deals with design of controller for dc-dc buck converter using various control techniques. The first two control techniques are based on classical or linear control methods i.e. PI and PID control, while the other two control technique are based on non linear control method i.e. Sliding Mode Control (SMC) and Sliding Mode Proportional Integral Derivative Control (SMC-PID). The output voltage and the inductor current of the applied control techniques are analyzed and compared in transient and steady state region. Also the robustness of the buck converter system is tested for load changes and input voltage variations. Matlab/Simulink is used for the simulations. The detailed simulation results are presented, which compare the performance of the designed controllers for various cases. The results show that the non linear control for DC/DC Buck converter proves to be more robust than linear control especially when dynamic tests are applied.

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