scholarly journals Ultrasound Echogenicity as an Indicator of Muscle Fatigue during Functional Electrical Stimulation

Sensors ◽  
2022 ◽  
Vol 22 (1) ◽  
pp. 335
Author(s):  
Qiang Zhang ◽  
Ashwin Iyer ◽  
Krysten Lambeth ◽  
Kang Kim ◽  
Nitin Sharma
Keyword(s):  
Electrical Stimulation ◽  
Muscle Fatigue ◽  
Functional Electrical Stimulation ◽  
Controller Design ◽  
Experimental Results ◽  
Computationally Efficient ◽  
Mobility Impairments ◽  
The Us ◽  
Relative Change ◽  
Functional Movements

Functional electrical stimulation (FES) is a potential neurorehabilitative intervention to enable functional movements in persons with neurological conditions that cause mobility impairments. However, the quick onset of muscle fatigue during FES is a significant challenge for sustaining the desired functional movements for more extended periods. Therefore, a considerable interest still exists in the development of sensing techniques that reliably measure FES-induced muscle fatigue. This study proposes to use ultrasound (US) imaging-derived echogenicity signal as an indicator of FES-induced muscle fatigue. We hypothesized that the US-derived echogenicity signal is sensitive to FES-induced muscle fatigue under isometric and dynamic muscle contraction conditions. Eight non-disabled participants participated in the experiments, where FES electrodes were applied on their tibialis anterior (TA) muscles. During a fatigue protocol under either isometric and dynamic ankle dorsiflexion conditions, we synchronously collected the isometric dorsiflexion torque or dynamic dorsiflexion angle on the ankle joint, US echogenicity signals from TA muscle, and the applied stimulation intensity. The experimental results showed an exponential reduction in the US echogenicity relative change (ERC) as the fatigue progressed under the isometric (R2=0.891±0.081) and dynamic (R2=0.858±0.065) conditions. The experimental results also implied a strong linear relationship between US ERC and TA muscle fatigue benchmark (dorsiflexion torque or angle amplitude), with R2 values of 0.840±0.054 and 0.794±0.065 under isometric and dynamic conditions, respectively. The findings in this study indicate that the US echogenicity signal is a computationally efficient signal that strongly represents FES-induced muscle fatigue. Its potential real-time implementation to detect fatigue can facilitate an FES closed-loop controller design that considers the FES-induced muscle fatigue.

scholarly journals Investigation of different stimulation patterns with doublet pulses to reduce muscle fatigue

2019 ◽  
Vol 6 ◽  
pp. 205566831982580 ◽  
Author(s):  
Ruslinda Ruslee ◽  
Jennifer Miller ◽  
Henrik Gollee
Keyword(s):  
Electrical Stimulation ◽  
Muscle Fatigue ◽  
Functional Electrical Stimulation ◽  
Muscle Activation ◽  
Motor Units ◽  
Pulse Interval ◽  
Time Interval ◽  
Fatigue Index ◽  
Significant Difference ◽  
Cord Injury

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.

Functional Electrical Stimulation (FES) Control for Restoration and Rehabilitation of Motor Function

2012 ◽  
pp. 80-93
Author(s):  
Takashi Watanabe ◽  
Naoto Miura
Keyword(s):  
Electrical Stimulation ◽  
Motor Function ◽  
Functional Electrical Stimulation ◽  
Wearable Sensors ◽  
Integrated System ◽  
Rehabilitation Training ◽  
Cord Injury ◽  
Feedback Error Learning ◽  
Feedback Error ◽  
Functional Movements

Functional electrical stimulation (FES) has been studied and clinically applied to restoring or assisting motor functions lost due to spinal cord injury or cerebrovascular disease. Electrical stimulation without control of functional movements is also used for therapy or in rehabilitation training. In recent years, one of the main focuses of FES studies has been its application for rehabilitation of motor function. In this review, the authors first present the basics of applying electrical stimulation to the neuromuscular system for motor control. Then, two methods of FES control are discussed: controllers for FES based on feedback error learning (FEL) and on cycle-to-cycle control of limb movements. The FEL-FES controller can be practical in FES applications that need to control the musculoskeletal system that involves various nonlinear characteristics and delay in its responses to electrical stimulation. The cycle-to-cycle control is expected to be effective in controlling repetitive movements for rehabilitation training. Finally, a study on ankle dorsiflexion control during the swing phase using an integrated system of FES control and motion measurement with wearable sensors for rehabilitation is presented.

scholarly journals Reporting for Duty: The duty cycle in Functional Electrical Stimulation research. Part I: Critical commentaries of the literature

2018 ◽  
Vol 28 (4) ◽  
Author(s):  
Matthew J. Taylor ◽  
Ché Fornusek ◽  
Andrew J. Ruys
Keyword(s):  
Electrical Stimulation ◽  
Muscle Contraction ◽  
Muscle Fatigue ◽  
Functional Electrical Stimulation ◽  
Duty Cycle ◽  
Cycle Time ◽  
Pulse Width ◽  
External Work ◽  
Stimulation Experiments ◽  
Frequency Pulse

There are several parameters that can be modulated during electrical stimulation-induced muscle contraction to obtain external work, i.e., Functional Electrical Stimulation (FES). The literature has several reports of the relationships of parameters such as frequency, pulse width, amplitude and physiological or biomechanical outcomes (i.e., torque) when these parameters are changed. While these relationships are well-described, lesser known across the literature is how changing the duty cycle (time ON and time OFF) of stimulation affects the outcomes. This review provides an analysis of the literature pertaining to the duty cycle in electrical stimulation experiments. There are two distinct sections of this review – an introduction to the duty cycle and definitions from literature (part I); and contentions from the literature and proposed frameworks upon which duty cycle can be interpreted (part II). It is envisaged that the two reviews will highlight the importance of modulating the duty cycle in terms of muscle fatigue in mimicking physiological activities. The frameworks provided will ideally assist in unifying how researchers consider the duty cycle in electrical stimulation (ES) of muscles.

scholarly journals Potential of M-Wave Elicited by Double Pulse for Muscle Fatigue Evaluation in Intermittent Muscle Activation by Functional Electrical Stimulation for Motor Rehabilitation

2016 ◽  
Vol 2016 ◽  
pp. 1-12
Author(s):  
Naoto Miura ◽  
Takashi Watanabe
Keyword(s):  
Electrical Stimulation ◽  
Muscle Fatigue ◽  
Functional Electrical Stimulation ◽  
Muscle Activation ◽  
Double Pulse ◽  
Motor Rehabilitation ◽  
Isometric Condition ◽  
M Wave ◽  
Repetitive Movements ◽  
Fatigue Evaluation

Clinical studies on application of functional electrical stimulation (FES) to motor rehabilitation have been increasing. However, muscle fatigue appears early in the course of repetitive movement production training by FES. Although M-wave variables were suggested to be reliable indices of muscle fatigue in long lasting constant electrical stimulation under the isometric condition, the ability of M-wave needs more studies under intermittent stimulation condition, because the intervals between electrical stimulations help recovery of muscle activation level. In this paper, M-waves elicited by double pulses were examined in muscle fatigue evaluation during repetitive movements considering rehabilitation training with surface electrical stimulation. M-waves were measured under the two conditions of repetitive stimulation: knee extension force production under the isometric condition and the dynamic movement condition by knee joint angle control. Amplitude of M-wave elicited by the 2nd pulse of a double pulse decreased during muscle fatigue in both measurement conditions, while the change in M-waves elicited by single pulses in a stimulation burst was not relevant to muscle fatigue in repeated activation with stimulation interval of 1 s. Fatigue index obtained from M-waves elicited by 2nd pulses was suggested to provide good estimation of muscle fatigue during repetitive movements with FES.

scholarly journals A flexible standalone system with integrated sensor feedback for multi-pad electrode FES of the hand

2016 ◽  
Vol 2 (1) ◽  
pp. 391-394 ◽  
Author(s):  
Jan C. Loitz ◽  
Aljoscha Reinert ◽  
Ann-Kristin Neumann ◽  
Fanny Quandt ◽  
Dietmar Schroeder ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Muscle Fatigue ◽  
Functional Electrical Stimulation ◽  
Electrode Placement ◽  
Treatment Efficiency ◽  
Integrated Sensor ◽  
Correct Placement ◽  
Cord Injury ◽  
Early Occurrence ◽  
Stimulation Electrode

AbstractFunctional electrical stimulation aims to help patients suffering from stroke or spinal cord injury to supplement lost motor function. Effective functional electrical stimulation requires precise placement of the stimulation electrode. Finding the correct placement, however, can be difficult and time consuming. Another common problem with functional electrical stimulation is early occurrence of muscle fatigue upon repetitive stimulation, limiting treatment efficiency. Both, precise electrode placement as well as the reduction of muscle fatigue can be achieved using multi-pad electrodes. Here we present a new standalone device for multi-pad functional electrical stimulation. The device is easy to use and designed to help patients recovering from stroke to train and perform opening of the hand.

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