scholarly journals Self-Triggered Functional Electrical Stimulation During Swallowing

2005 ◽  
Vol 94 (6) ◽  
pp. 4011-4018 ◽  
Author(s):  
Theresa A. Burnett ◽  
Eric A. Mann ◽  
Joseph B. Stoklosa ◽  
Christy L. Ludlow

Hyolaryngeal elevation is essential for airway protection during swallowing and is mainly a reflexive response to oropharyngeal sensory stimulation. Targeted intramuscular electrical stimulation can elevate the resting larynx and, if applied during swallowing, may improve airway protection in dysphagic patients with inadequate hyolaryngeal motion. To be beneficial, patients must synchronize functional electrical stimulation (FES) with their reflexive swallowing and not adapt to FES by reducing the amplitude or duration of their own muscle activity. We evaluated the ability of nine healthy adults to manually synchronize FES with hyolaryngeal muscle activity during discrete swallows, and tested for motor adaptation. Hooked-wire electrodes were placed into the mylo- and thyrohyoid muscles to record electromyographic activity from one side of the neck and deliver monopolar FES for hyolaryngeal elevation to the other side. After performing baseline swallows, volunteers were instructed to trigger FES with a thumb switch in synchrony with their swallows for a series of trials. An experimenter surreptitiously disabled the thumb switch during the final attempt, creating a foil. From the outset, volunteers synchronized FES with the onset of swallow-related thyrohyoid activity (∼225 ms after mylohyoid activity onset), preserving the normal sequence of muscle activation. A comparison between average baseline and foil swallows failed to show significant adaptive changes in the amplitude, duration, or relative timing of activity for either muscle, indicating that the central pattern generator for hyolaryngeal elevation is immutable with short term stimulation that augments laryngeal elevation during the reflexive, pharyngeal phase of swallowing.

2020 ◽  
Vol 11 (1) ◽  
pp. 7
Author(s):  
Antonino Casabona ◽  
Maria Stella Valle ◽  
Claudio Dominante ◽  
Luca Laudani ◽  
Maria Pia Onesta ◽  
...  

The benefits of functional electrical stimulation during cycling (FES-cycling) have been ascertained following spinal cord injury. The instrumented pendulum test was applied to chronic paraplegic patients to investigate the effects of FES-cycling of different duration (20-min vs. 40-min) on biomechanical and electromyographic characterization of knee mobility. Seven adults with post-traumatic paraplegia attended two FES-cycling sessions, a 20-min and a 40-min one, in a random order. Knee angular excursion, stiffness and viscosity were measured using the pendulum test before and after each session. Surface electromyographic activity was recorded from the rectus femoris (RF) and biceps femoris (BF) muscles. FES-cycling led to reduced excursion (p < 0.001) and increased stiffness (p = 0.005) of the knee, which was more evident after the 20-min than 40-min session. Noteworthy, biomechanical changes were associated with an increase of muscle activity and changes in latency of muscle activity only for 20-min, with anticipated response times for RF (p < 0.001) and delayed responses for BF (p = 0.033). These results indicate that significant functional changes in knee mobility can be achieved by FES-cycling for 20 min, as evaluated by the pendulum test in patients with chronic paraplegia. The observed muscle behaviour suggests modulatory effects of exercise on spinal network aimed to partially restore automatic neuronal processes.


2018 ◽  
Vol 124 (1) ◽  
pp. 10-15 ◽  
Author(s):  
Keizo Takahashi ◽  
Kazuhiro Hori ◽  
Hirokazu Hayashi ◽  
Masako Fujiu-Kurachi ◽  
Takahiro Ono ◽  
...  

Surface electrical stimulation of the laryngeal region is used to improve swallowing in dysphagic patients. However, little is known about how electrical stimulation affects tongue movements and related functions. We investigated the effect of electrical stimulation on tongue pressure and hyoid movement, as well as suprahyoid and infrahyoid muscle activity, in 18 healthy young participants. Electrical stimulation (0.2-ms duration, 80 Hz, 80% of each participant’s maximal tolerance) of the laryngeal region was applied. Each subject swallowed 5 ml of barium sulfate liquid 36 times at 10-s intervals. During the middle 2 min, electrical stimulation was delivered. Tongue pressure, electromyographic activity of the suprahyoid and infrahyoid muscles, and videofluorographic images were simultaneously recorded. Tongue pressure during stimulation was significantly lower than before or after stimulation and was significantly greater after stimulation than at baseline. Suprahyoid activity after stimulation was larger than at baseline, while infrahyoid muscle activity did not change. During stimulation, the position of the hyoid at rest was descended, the highest hyoid position was significantly inferior, and the vertical movement was greater than before or after stimulation. After stimulation, the positions of the hyoid at rest and at the maximum elevation were more superior than before stimulation. The deviation of the highest positions of the hyoid before and after stimulation corresponded to the differences in tongue pressures at those times. These results suggest that surface electrical stimulation applied to the laryngeal region during swallowing may facilitate subsequent hyoid movement and tongue pressure generation after stimulation. NEW & NOTEWORTHY Surface electrical stimulation applied to the laryngeal region during swallowing may facilitate subsequent hyoid movement and tongue pressure generation after stimulation. Tongue muscles may contribute to overshot recovery more than hyoid muscles.


2019 ◽  
Vol 6 ◽  
pp. 205566831982580 ◽  
Author(s):  
Ruslinda Ruslee ◽  
Jennifer Miller ◽  
Henrik Gollee

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.


2008 ◽  
Vol 100 (1) ◽  
pp. 482-494 ◽  
Author(s):  
Chad V. Anderson ◽  
Andrew J. Fuglevand

Functional electrical stimulation (FES) involves artificial activation of muscles with implanted electrodes to restore motor function in paralyzed individuals. The range of motor behaviors that can be generated by FES, however, is limited to a small set of preprogrammed movements such as hand grasp and release. A broader range of movements has not been implemented because of the substantial difficulty associated with identifying the patterns of muscle stimulation needed to elicit specified movements. To overcome this limitation in controlling FES systems, we used probabilistic methods to estimate the levels of muscle activity in the human arm during a wide range of free movements based on kinematic information of the upper limb. Conditional probability distributions were generated based on hand kinematics and associated surface electromyographic (EMG) signals from 12 arm muscles recorded during a training task involving random movements of the arm in one subject. These distributions were then used to predict in four other subjects the patterns of muscle activity associated with eight different movement tasks. On average, about 40% of the variance in the actual EMG signals could be accounted for in the predicted EMG signals. These results suggest that probabilistic methods ultimately might be used to predict the patterns of muscle stimulation needed to produce a wide array of desired movements in paralyzed individuals with FES.


2020 ◽  
pp. 833-851
Author(s):  
Poulami Ghosh ◽  
Ankita Mazumder ◽  
Anwesha Banerjee ◽  
D.N. Tibarewala

Loss or impairment in the ability of muscle movement or sensation is called Paralysis which is caused by disruption of communication of nerve impulses along the pathway from the brain to the muscles. One of the principal reasons causing paralysis is Spinal Cord Injury (SCI) and Neurological rehabilitation by using neuro-prostheses, based on Functional Electrical Stimulation (FES) is extensively used for its treatment. Impaired muscles are activated by applying small amplitude electrical current. Electromyography (EMG), the recording of biosignals generated by muscle activity during the application of FES can be used as the control signal for FES based rehabilitative devices. This method is predominantly used for restoring upper extremity functioning (wrist, hand, elbow, etc.), standing, walking (speed, pattern) in stroke patients. FES, collaborated with conventional methods, has the potential to be utilized as a useful tool for rehabilitation and restoration of muscle strength, metabolic responses etc. in paralyzed patients.


Author(s):  
Jetsada Arnin ◽  
Traisak Yamsa-ard ◽  
Preechapawan Triponyuwasin ◽  
Yodchanan Wongsawat

The purpose of this study was to develop a functional electrical stimulation (FES) system based on the motor driving concept for use by spinal cord injury patients participating in the FES Cycling competition at the Cybathlon 2016. The proposed FES system consists of a low-power control system, a precise processor unit, and a 4-channel stimulation unit. Self-adhesive carbon conductive electrodes were utilized for stimulation. A 26-year-old SCI patient was qualified to participate in the competition. The pilot patient underwent training for 16 months, which included experience with FES stimulation, performing FES cycling, and reducing spasticity, to practice using the FES system. In addition, using surface electromyography (EMG) during cycling, the muscle activation pattern for generating the stimulation profile was applied and resulted in good performance. The best FES cycling performance the pilot achieved was 1000 meters translation with the cycling system during twelve minutes of using the FES system. The pilot achieved an 1000 meters translation mobility within an average of 16 minutes of cycling. Nevertheless, the system must be further investigated regarding muscle fatigue and other factors that may affect the stimulation conditions.


2002 ◽  
Vol 283 (3) ◽  
pp. G529-G536 ◽  
Author(s):  
Ivan M. Lang ◽  
Nicole Dana ◽  
Bidyut K. Medda ◽  
Reza Shaker

We investigated the mechanisms of airway protection and bolus transport during retching and vomiting by recording responses of the pharyngeal, laryngeal, and hyoid muscles and comparing them with responses during swallowing and responses of the gastrointestinal tract. Five dogs were chronically instrumented with electrodes on the striated muscles and strain gauges on smooth muscles. Retching and vomiting were stimulated by apomorphine (5–10 ug/kg iv). During retching, the hyoid and thyroid descending and laryngeal abductor muscles were activated; between retches, the hyoid, thyroid, and pharyngeal elevating, and laryngeal adductor muscles were activated. Vomiting always occurred during the ascending phase of retching and consisted of three sequential phases of hyoid and pharyngeal muscle activation culminating in simultaneous activation of all recorded elevating and descending laryngeal, hyoid, and pharyngeal muscles. Retrograde activation of esophagus and pharyngeal muscles occurred during the later phases, and laryngeal adductor was maximally activated in all phases of the vomit. During swallowing, the laryngeal adductor activation was followed immediately by brief activation of the laryngeal abductor. We concluded that retching functions to mix gastric contents with refluxed intestinal secretions and to impart an orad momentum to the bolus before vomiting. During retches, the airway is protected by glottal closure, and between retches, it is protected by ascent of the larynx and closure of the upper esophageal sphincter. The airway is protected by maximum glottal closure during vomiting. During swallowing, the airway is protected by laryngeal elevation and glottal closure followed by brief opening of the glottis, which may release subglottal pressure expelling material from the laryngeal vestibule.


Author(s):  
Qiang Zhang ◽  
Ashwin Iyer ◽  
Ziyue Sun ◽  
Albert Dodson ◽  
Nitin Sharma

Abstract Functional electrical stimulation (FES) is a potential technique for reanimating paralyzed muscles post neurological injury/disease. Several technical challenges including difficulty in measuring and compensating for delayed muscle activation levels inhibit its satisfactory control performance. In this paper, an ultrasound (US) imaging approach is proposed to measure delayed muscle activation levels under the implementation of FES. Due to low sampling rates of US imaging, a sampled-data observer (SDO) is designed to estimate the muscle activation in a continuous manner. The SDO is combined with continuous-time dynamic surface control (DSC) approach that compensates for the electromechanical delay (EMD) in the tibialis anterior (TA) activation dynamics. The stability analysis based on the Lyapunov-Krasovskii function proves that the SDO-based DSC plus delay compensation (SDO-DSC-DC) approach achieves semi-global uniformly ultimately bounded (SGUUB) tracking performance. Simulation results on an ankle dorsiflexion neuromusculoskeletal system show the root mean square error (RMSE) of desired trajectory tracking is reduced by 19.77 % by using the proposed SDO-DSC-DC compared to the DSC-DC without the SDO. The findings provide potentials for rehabilitative devices, like powered exoskeleton and FES, to assist or enhance human limb movement based on the corresponding muscle activities in real-time.


2016 ◽  
Vol 2016 ◽  
pp. 1-12
Author(s):  
Naoto Miura ◽  
Takashi Watanabe

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.


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