Signaling In Muscle Research Articles

Combined transcriptome and metabolome analysis reveals breed-specific regulatory mechanisms in Dorper and Tan sheep

BackgroundDorper and Tan sheep are renowned for their rapid growth and exceptional meat quality, respectively. Previous research has provided evidence of the impact of gut microbiota on breed characteristics. The precise correlation between the gastrointestinal tract and peripheral organs in each breed is still unclear. Investigating the metabolic network of the intestinal organ has the potential to improve animal growth performance and enhance economic benefits through the regulation of intestinal metabolites.ResultsIn this study, we identified the growth advantage of Dorper sheep and the high fat content of Tan sheep. A transcriptome study of the brain, liver, skeletal muscle, and intestinal tissues of both breeds revealed 3,750 differentially expressed genes (DEGs). The genes PPARGC1A, LPL, and PHGDH were found to be highly expressed in Doper, resulting in the up-regulation of pathways related to lipid oxidation, glycerophospholipid metabolism, and amino acid anabolism. Tan sheep highly express the BSEP, LDLR, and ACHE genes, which up-regulate the pathways involved in bile transport and cholesterol homeostasis. Hindgut content analysis identified 200 differentially accumulated metabolites (DAMs). Purines, pyrimidines, bile acids, and fatty acid substances were more abundant in Dorper sheep. Based on combined gene and metabolite analyses, we have identified glycine, serine, and threonine metabolism, tryptophan metabolism, bile secretion, cholesterol metabolism, and neuroactive ligand-receptor interaction as key factors contributing to the differences among the breeds.ConclusionsThis study indicates that different breeds of sheep exhibit unique breed characteristics through various physiological regulatory methods. Dorper sheep upregulate metabolic signals related to glycine, serine, and threonine, resulting in an increase in purine and pyrimidine substances. This, in turn, promotes the synthesis of amino acids and facilitates body development, resulting in a faster rate of weight gain. Tan sheep accelerate bile transport, reduce bile accumulation in the intestine, and upregulate cholesterol homeostasis signals in skeletal muscles. This promotes the accumulation of peripheral and intramuscular fat, resulting in improved meat quality. This work adopts a joint analysis method of multi-tissue transcriptome and gut metabolome, providing a successful case for analyzing the mechanisms underlying the formation of various traits.

Modified motor unit properties in residual muscle following transtibial amputation

Objective. Neural signals in residual muscles of amputated limbs are frequently decoded to control powered prostheses. Yet myoelectric controllers assume muscle activities of residual muscles are similar to that of intact muscles. This study sought to understand potential changes to motor unit (MU) properties after limb amputation. Approach. Six people with unilateral transtibial amputation were recruited. Surface electromyogram (EMG) of residual and intact tibialis anterior (TA) and gastrocnemius (GA) muscles were recorded while subjects traced profiles targeting up to 20% and 35% of maximum activation for each muscle (isometric for intact limbs). EMG was decomposed into groups of MU spike trains. MU recruitment thresholds, action potential amplitudes (MU size), and firing rates were correlated to model Henneman’s size principle, the onion-skin phenomenon, and rate-size associations. Organization (correlation) and modulation (rates of change) of relations were compared between intact and residual muscles. Main results. The residual TA exhibited significantly lower correlation and flatter slopes in the size principle and onion-skin, and each outcome covaried between the MU relations. The residual GA was unaffected for most subjects. Subjects trained prior with myoelectric prostheses had minimally affected slopes in the TA. Rate-size association correlations were preserved, but both residual muscles exhibited flatter decay rates. Significance. We showed peripheral neuromuscular damage also leads to spinal-level functional reorganizations. Our findings suggest models of MU recruitment and discharge patterns for residual muscle EMG generation need reparameterization to account for disturbances observed. In the future, tracking MU pool adaptations may also provide a biomarker of neuromuscular control to aid training with myoelectric prostheses.

Ultrasound Pressure-Dependent Cytokine and Immune Cell Response Lost in Aged Muscle

ObjectiveTherapeutic ultrasound remains a highly discussed topic in physical therapy due to uncertainty between treatment regimens and biological benefits. Its impact on aged populations, who are vulnerable to insufficient healing after muscle injury due to sarcopenia, is understudied. Despite the coupling between muscle inflammation and regeneration, research on the immune response after therapeutic ultrasound is limited. The objective of this study was to evaluate structure, inflammatory cytokine signaling and immune cell infiltration after therapeutic ultrasound in young and aging murine muscle. MethodsYoung (6-weeks-old) and Adult (52-weeks-old) male and female mice non-injured gastrocnemii were treated with either low intensity pulsed ultrasound at 2 W/cm2 (∼0.243 MPa) or high intensity pulsed focused ultrasound at 554 W/cm2 (∼5.96 MPa). Cytokine expression was evaluated at 1-, 8-, and 24-hours, cell infiltration was measured via flow cytometry at 1- and 24-hours, and immunofluorescence assessed muscle fiber area, fibrosis and satellite cells at 24-hours after sonication. ResultsLow intensity pulsed ultrasound induced an early, transient inflammatory response where IL-15 and macrophages (M2 > M1) were increased 1-hour post-sonication. High intensity pulsed focused ultrasound caused a late, extended immune response where MCP-1, neutrophils, monocytes, and macrophages (M1 > M2) were increased 24-hours post-sonication. Notably, these changes manifested solely in Young gastrocnemius. The Adult gastrocnemius exhibited decreased cytokine expression (IL-1α, IL-6, IL-15, M-CSF) and no alteration in immune cell recruitment post-sonication. There was no damage to muscle structure. ConclusionsTherapeutic ultrasound induced a pressure dependent inflammatory response that can augment or mitigate intrinsic muscle cytokine signaling and cell recruitment in adolescent or aged muscle, respectively.

Independent and combined effects of calorie restriction and AICAR on glucose uptake and insulin signaling in skeletal muscles from 24-month-old female and male rats.

We assessed the effects of two levels of calorie restriction (CR; eating either 15% or 35% less than ad libitum, AL, food intake for 8 weeks) by 24-month-old female and male rats on glucose uptake (GU) and phosphorylation of key signaling proteins (Akt; AMP-activated protein kinase, AMPK; Akt substrate of 160kDa, AS160) measured in isolated skeletal muscles that underwent four incubation conditions (without either insulin or AICAR, an AMPK activator; with AICAR alone; with insulin alone; or with insulin and AICAR). Regardless of sex: (1) neither CR group versus the AL group had greater GU by insulin-stimulated muscles; (2) phosphorylation of Akt in insulin-stimulated muscles was increased in 35% CR versus AL rats; (3) prior AICAR treatment of muscle resulted in greater GU by insulin-stimulated muscles, regardless of diet; and (4) AICAR caused elevated phosphorylation of acetyl CoA carboxylase, an indicator of AMPK activation, in all diet groups. There was a sexually dimorphic diet effect on AS160 phosphorylation, with 35% CR exceeding AL for insulin-stimulated muscles in male rats, but not in female rats. Our working hypothesis is that the lack of a CR-effect on GU by insulin-stimulated muscles was related to the extended duration of the ex vivo incubation period (290 min compared to 40-50 min that was previously reported to be effective). The observed efficacy of prior treatment of muscles with AICAR to improve glucose uptake in insulin-stimulated muscles supports the strategy of targeting AMPK with the goal of improving insulin sensitivity in older females and males.

The transmembrane protein TMEM182 promotes fat deposition and alters metabolomics and lipidomics

TMEM182, a transmembrane protein highly expressed in muscle and adipose tissues, plays a crucial role in muscle cell differentiation, metabolism, and signaling. However, its role in fat deposition and metabolism is still unknown. In this study, we used overexpression and knockout models to examine the impact of TMEM182 on fat synthesis and metabolism. Our results showed that TMEM182 overexpression increased the expression of fat synthesis-related genes and promoted the differentiation of preadipocytes into fat cells. In TMEM182 knockout mice, there was a significant decrease in abdominal fat deposition. RNA sequencing results showed that TMEM182 overexpression in preadipocytes enhanced the activity of pathways related to fat formation, ECM-receptor interaction, and cell adhesion. Furthermore, our analysis using UPLC-MS/MS showed that TMEM182 significantly altered the metabolite and lipid content and composition in chicken breast muscle. Specifically, TMEM182 increased the content of amino acids and their derivatives in chicken breast muscle, promoting amino acid metabolic pathways. Lipidomics also revealed a significant increase in the content of glycerophospholipids, sphingolipids, and phospholipids in the breast muscle after TMEM182 overexpression. These findings suggest that TMEM182 plays a crucial role in regulating fat deposition and metabolism, making it a potential target for treating obesity-related diseases and animal breeding.

Learning a Hand Model from Dynamic Movements Using High-Density EMG and Convolutional Neural Networks.

Surface electromyography (sEMG) can sense the motor commands transmitted to the muscles. This work presents a deep learning method that can decode the electrophysiological activity of the forearm muscles into the movements of the human hand. We have recorded the kinematics and kinetics of the hand during a wide range of grasps and individual digit movements that cover 22 degrees of freedom of the hand at slow (0.5 Hz) and comfortable (1.5 Hz) movement speeds in 13 healthy participants. The input of the model consists of 320 non-invasive EMG sensors placed on the extrinsic hand muscles. Our network achieves accurate continuous estimation of both kinematics and kinetics, surpassing the performance of comparable networks reported in the literature. By examining the latent space of the network, we find evidence that it mapped EMG activity into the anatomy of the hand at the individual digit level. In contrast to what is observed from the low-pass filtered EMG and linear decoding approaches, we found that the full-bandwidth EMG (monopolar unfiltered) signals during synergistic and individual digit movements contain distinct neural embeddings that encode each movement of the human hand. These manifolds consistently represent the anatomy of the hand and are generalized across participants. Moreover, we found a task-specific distribution of the embeddings without any presence of correlated activations during multi- and individual-digit tasks. The proposed method could advance the control of assistive hand devices by providing a robust and intuitive interface between muscle signals and hand movements.

Effects of preconditioning with heat stress on acute exercise-induced intracellular signaling in male rat gastrocnemius muscle.

Heat stress (HS) induces Akt/mTOR phosphorylation and FoxO3a signaling; however, whether a prior increase in heat shock protein 72 (HSP72) expression affects intracellular signaling following eccentric exercise remains unclear. We analyzed the effects of HS pretreatment on intramuscular signaling in response to acute exercise in 10-week-old male Wistar rats (n = 24). One leg of each rat was exposed to HS and the other served as an internal control (CT). Post-HS, rats were either rested or subjected to downhill treadmill running. Intramuscular signaling responses in the red and white regions of the gastrocnemius muscle were analyzed before, immediately after, or 1 h after exercise (n = 8/group). HS significantly increased HSP72 levels in both deep red and superficial white regions. Although HS did not affect exercise-induced mTOR signaling (S6K1/ERK) responses in the red region, mTOR phosphorylation in the white region was significantly higher in CT legs than in HS legs after exercise. Thr308 phosphorylation of Akt showed region-specific alteration with a decrease in the red region and an increase in the white region immediately after downhill running. Overall, a prior increase in HSP72 expression elicits fiber type-specific changes in exercise-induced Akt and mTOR phosphorylation in rat gastrocnemius muscle.

Comparative electromyography analysis of subphase gait disorder in chronic stroke survivors.

Abnormal lower limb muscle activity is the most common cause of the alterative pattern of gait in stroke survivors, resulting from spastic and paralytic muscles around the hip, knee, and ankle joints. However, the activity of the major lower limb muscles that control the legs to facilitate walking in stroke patients have not been clearly understood in each subphase of the gait. This study differentiated the characteristics of surface electromyography (sEMG) signals of lower limb muscles during four subphases of gait cycle between stroke patients and healthy subjects. Sixteen chronic stroke patients and sixteen healthy subjects were recruited. All participants completed three walking trials with a self-selected walking speed. The sEMG signals were recorded on the gluteus medius, rectus femoris, long head of biceps femoris, medial gastrocnemius, tibialis anterior, and peroneus longus muscles. The characteristics of sEMG signals were processed and analyzed in the time and frequency features, considering the first double support, single support, second double support, and swing phases of the gait cycle.The stroke patients had altered sEMG characteristics on both paretic and non-paretic sides compared to healthy subjects across the sub-phases of gait cycle for all six muscles. All time domain features of sEMG signal showed that the medial gastrocnemius muscle has the most significant impaired activity (p<0.05) and affected gait disturbance during all four subphases of the gait cycle. The findings demonstrated that the medial gastrocnemius muscle had impaired activity and was most affected during all four sub-phases of the gait cycle. This indicates that sEMG of medial gastrocnemius muscle can be used to measure the improvement of gait rehabilitation.

ShRNA-mediated down-regulation of Acsl1 reverses skeletal muscle insulin resistance in obese C57BL6/J mice.

Prolonged consumption of diet rich in fats is regarded as the major factor leading to the insulin resistance (IR) and type 2 diabetes (T2D). Emerging evidence link excessive accumulation of bioactive lipids such as diacylglycerol (DAG) and ceramide (Cer), with impairment of insulin signaling in skeletal muscle. Until recently, little has been known about the involvement of long-chain acyl-CoAs synthetases in the above mechanism. To examine possible role of long-chain acyl-coenzyme A synthetase 1 (Acsl1) (a major muscular ACSL isoform) in mediating HFD-induced IR we locally silenced Acsl1 in gastrocnemius of high-fat diet (HFD)-fed C57BL/6J mice through electroporation-delivered shRNA and compared it to non-silenced tissue within the same animal. Acsl1 down-regulation decreased the content of muscular long-chain acyl-CoA (LCACoA) and both the Cer (C18:1-Cer and C24:1-Cer) and DAG (C16:0/18:0-DAG, C16:0/18:2-DAG, C18:0/18:0-DAG) and simultaneously improved insulin sensitivity and glucose uptake as compared with non-silenced tissue. Acsl1 down-regulation decreased expression of mitochondrial β-oxidation enzymes, and the content of both the short-chain acylcarnitine (SCA-Car) and short-chain acyl-CoA (SCACoA) in muscle, pointing towards reduction of mitochondrial FA oxidation. The results indicate, that beneficial effects of Acsl1 partial ablation on muscular insulin sensitivity are connected with inhibition of Cer and DAG accumulation, and outweigh detrimental impact of decreased mitochondrial fatty acids metabolism in skeletal muscle of obese HFD-fed mice.

Study of the internal mechanism of attention focus affecting countermovement jump performance based on muscle synergy theory.

The purpose of this study was to explain the internal mechanism of attention focus affecting performance of countermovement jump based on muscle synergy theory. Participants involved untrained group(N = 10) and high-level group(N = 11). Subjects performed countermovement jump with internal attention focus instruction (IF), external distal attention focus instruction (EDF), and external proximal attention focus instruction (EPF). The electromyography (EMG) signals of the dominant vastus lateralis muscle (VL), semitendinosus muscle (ST), tibial anterior muscle (TA), rectus femoris muscle (RF), and medial gastrocnemius (MG) were recorded. The non-negative matrix factorization was used to extract muscle synergy. 1) Attention focus did not affect countermovement jump performance and the number of muscle synergy in the high-level group (P>0.05). 2) Attention focus instructions affected the untrained group countermovement jump (P<0.05). and EDF and EPF reduced the number of muscle synergy. 3)The Cohen's d of EDF (0.269) was less than EPF (0.377) in untrained group. For the untrained people, the improved motor performance caused by attention focus resembled the adaptive changes that occur with long-term training. The reason why an EDF is superior to EPF is that the former produces more thorough changes in muscle synergy.

Online Removal of Cardiac Artifacts from Respiratory Surface Electromyograms

Surface electromyographic (sEMG) signals of the respiratory muscles can be used for assessing patient activity during mechanical ventilation. However, the measured signals are usually heavily contaminated by the electrical activity of the heart. In this paper, an online algorithm for real-time respiratory sEMG denoising by means of the stationary wavelet transform (SWT) is presented. It was analyzed on a dataset of healthy patients and was found to perform comparably to an offline SWT algorithm on several metrics. Online processing ofers the potential to improve the therapy of ventilated patients directly at the bedside.

Maternal Protein Restriction Inhibits Insulin Signaling and Insulin Resistance in the Skeletal Muscle of Young Adult Rats.

Infants with fetal growth restriction (FGR) are at a risk of developing metabolic syndromes in adulthood. We hypothesized that skeletal muscle degeneration by nutrition-restricted FGR results in abnormal insulin signaling and epigenetic changes. To develop a protein-restricted FGR model, rats were fed a low-protein diet (7% protein) during the gestational period; rats fed a normal diet (20% protein) were used as controls. At 8 and 12 weeks of age, the pups were subjected to oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) to evaluate insulin resistance. At 12 weeks, the mRNA and protein levels of insulin signaling pathway molecules in the skeletal muscles were examined. DNA methylation of promoters was detected. DNA extracted from skeletal muscles was used as a template for methylation-specific PCR analysis of GLUT4. The body weight of FGR rats from birth to 8 weeks was significantly lower than that of the controls; no significant difference was observed between the groups at 12 weeks. In the OGTT and ITT, the incremental area under the curve (iAUC) was significantly higher in FGR rats than in the controls at 12 weeks. The mRNA and protein levels of Akt2 and GLUT4 in the plantar muscles were significantly lower in FGR rats than in the controls. GLUT4 methylation was comparable between the groups. Protein-restricted FGR rats showed insulin resistance and altered insulin signaling in skeletal muscles after 12 weeks. However, we could not demonstrate the involvement of DNA methylation in this model.

Illusory Directional Sensation Induced by Asymmetric Vibrations Influences Sense of Agency and Velocity in Wrist Motions.

Illusory directional sensations are generated through asymmetric vibrations applied to the fingertips and have been utilized to induce upper-limb motions in the rehabilitation and training of patients with visual impairment. However, its effects on motor control remain unclear. This study aimed to verify the effects of illusory directional sensations on wrist motion. We conducted objective and subjective evaluations of wrist motion during a motor task, while inducing an illusory directional sensation that was congruent or incongruent with wrist motion. We found that, when motion and illusory directional sensations were congruent, the sense of agency for motion decreased. This indicates an induction sensation of the hand being moved by the illusion. Interestingly, although no physical force was applied to the hand, the angular velocity of the wrist was higher in the congruent condition than that in the no-stimulation condition. The angular velocity of the wrist and electromyography signals of the agonist muscles were weakly positively correlated, suggesting that the participants may have increased their wrist velocity. In other words, the congruence between the direction of motion and illusory directional sensation induced the sensation of the hand being moved, even though the participants' wrist-motion velocity increased. This phenomenon can be explained by the discrepancy between the sensation of active motion predicted by the efferent copy, and that of actual motion caused by the addition of the illusion. The findings of this study can guide the design of novel rehabilitation methods.

Role of toll-like receptor 4 in skeletal muscle damage in chronic limb-threatening ischemia

ObjectiveToll-like receptors (TLRs) are key pattern recognition receptors in the innate immune system. In particular, the TLR4-mediated immune response has been implicated in ischemia-induced tissue injury. Mounting evidence supports a detrimental role of the innate immune system in the pathophysiology of skeletal muscle damage in patients with chronic limb-threatening ischemia (CLTI), in whom patient-oriented functional outcomes are poor. The overall aim of this study was to investigate the potential role of TLR4 in skeletal muscle dysfunction and damage in CLTI. MethodsThe role of TLR4 in ischemic muscle was investigated by (1) studying TLR4 expression and distribution in human gastrocnemius muscle biopsies, (2) evaluating the functional consequences of TLR4 inhibition in myotubes derived from human muscle biopsies, and (3) assessing the therapeutic potential of modulating TLR4 signaling in ischemic muscle in a mouse hindlimb ischemia model. ResultsTLR4 was found to be expressed in human muscle biopsies, with significant upregulation in samples from patients with CLTI. In vitro studies using cultured human myotubes demonstrated upregulation of TLR4 in ischemia, with activation of the downstream signaling pathway. Inhibition of TLR4 before ischemia was associated with reduced ischemia-induced apoptosis. Upregulation of TLR4 also occurred in ischemia in vivo and TLR4 inhibition was associated with decreased inflammatory cell infiltration and diminished apoptosis in the ischemic limb. ConclusionsTLR4 is upregulated and activated in ischemic skeletal muscle in patients with CLTI. Modulating TLR4 signaling in vitro and in vivo was associated with attenuation of ischemia-induced skeletal muscle damage. This strategy could be explored further for potential clinical application.

Method for Evaluating Muscle Fatigue from Multi-channel Surface Electromyography Signals of Suprahyoid and Infrahyoid Muscles During Swallowing

Method for Evaluating Muscle Fatigue from Multi-channel Surface Electromyography Signals of Suprahyoid and Infrahyoid Muscles During Swallowing

Accessory respiratory muscles performance among people with spinal cord injury while singing songs with different musical parameters.

People with spinal cord injury (SCI) experience respiratory dysfunctions which include hypersecretions, bronchospasm, and respiratory muscles weakness. Singing therapy has been implemented as part of respiratory muscle training (RMT) to improve their muscle strength. Singing different types and genres of songs may elicit specific recruitment of respiratory muscles, attributed to the variation of the songs' characteristics including tempo, pitch, and rhythmic complexity. This study aims to determine the effect of singing songs with different characteristics on the accessory respiratory muscle performance among people with SCI. Thirteen male SCI participants of ASIA A and B (C4 -T11) were recruited. Respiratory muscle signals were retrieved by placing two mechanomyography (MMG) sensors on the sternocleidomastoid (SCM) and rectus abdominis (RA) muscles. Eight music experts categorized several songs into four categories based on their pitch, tempo, and rhythmic complexity. Each participant sang one song from each category. Findings showed statistically significant difference in RA and SCM responses among all categories (P < 0.01). The SCM muscle is most active while singing high pitch songs. While the RA is most active during slow tempo and easy rhythmic complexity. This shows that different accessory respiratory muscle is activated by people with SCI while singing songs with different characteristics. Clinicians could benefit from this knowledge while prescribing singing therapy or exercise among people with SCI in the future.

Ab. No. 54 Effect of EMG Driven Robotic-Assisted Rehabilitation on Hand Motor Function in Individuals With Stroke – Systematic Review

Introduction: After a stroke, more than 80% of survivors experience common upper limb motor deficits, particularly in distal extremities. The recovery process often involves restoring motor functions in hand. An innovative approach to this involves EMG-driven robotic assistant rehabilitation. By integrating EMG technology with robotics, this method utilizes muscle signals from the patient to control a robotic device, facilitating targeted exercises and promoting neural plasticity for improved hand mobility post-stroke. Enhance motor skills, improve Functionality, and accelerate the rehabilitation process by tailoring the intervention to the individual needs and progression. Methods: A bibliographic exploration covered electronic databases like Google Scholar, PUBMED, and ResearchGate, adhering to PRISMA guidelines. From 236 articles, 45 studies were scrutinized, with 10 meeting the inclusion criteria. Among these, 5 were (RCTs) (4 EMG-driven robotics with NMES, 1 EMG-driven robotics). There was 1 case report and 4 single-group studies (2 EMG-driven robotics and NMES, 2 EMG-driven robotics). Fugl-Meyer Assessment (FMA) and EMG parameters were outcome measures for hand motor function assessment. The Cochrane risk of bias tool was used to evaluate article bias. Result: Significant improvements in FMA and EMG parameters were observed in EMG-driven robotic-assisted rehabilitation. Similar findings were noted in EMG-driven robotic-assisted NMES-assisted rehabilitation. Conclusion: EMG-driven robotics enhance hand function and reduce spasticity, aiding stroke rehabilitation. Implications: Incorporating these technologies improves stroke rehabilitation, enhancing recovery outcomes for individuals with stroke

An Introduction to Electromyography Signal Processing and Machine Learning for Pattern Recognition: A Brief Overview

Electromyography (EMG) is about studying electrical signals from muscles and can provide a wealth of information on the function, contraction, and activity of your muscles. In the field of EMG pattern recognition, these signals are used to identify and categorize patterns linked to muscle activity. Various machine learning (ML) methods are used for this purpose. Successful detection of these patterns depends on using effective signal-processing techniques. It is crucial to reduce noise in EMG for accurate and meaningful information about muscle activity, improving signal quality for precise assessments. ML tools such as SVMs, neural networks, KNNs, and decision trees play a crucial role in sorting out complex EMG signals for different pattern recognition tasks. Clustering algorithms also help analyze and interpret muscle activity. EMG and ML find diverse uses in rehabilitation, prosthetics, and human-computer interfaces, though real-time applications come with challenges. They bring significant changes to prosthetic control, human-computer interfaces, and rehabilitation, playing a vital role in pattern recognition. They make prosthetic control more intuitive by understanding user intent from muscle signals, enhance human-computer interaction with responsive interfaces, and support personalized rehabilitation for those with motor impairments. The combination of EMG and ML opens doors for further research into understanding muscle behavior, improving feature extraction, and advancing classification algorithms.

I-MYO: A multi-grasp prosthetic hand control system based on gaze movements, augmented reality, and myoelectric signals.

Controlling a multi-grasp prosthetic hand still remains a challenge. This study explores the influence of merging gaze movements and augmented reality in bionics on improving prosthetic hand control. A control system based on gaze movements, augmented reality, and myoelectric signals (i-MYO) was proposed. In the i-MYO, the GazeButton was introduced into the controller to detect the grasp-type intention from the eye-tracking signals, and the proportional velocity scheme based on the i-MYO was used to control hand movement. The able-bodied subjects with no prior training successfully transferred objects in 91.6% of the cases and switched the optimal grasp types in 97.5%. The patient could successfully trigger the EMG to control the hand holding the objects in 98.7% of trials in around 3.2s and spend around 1.3s switching the optimal grasp types in 99.2% of trials. Merging gaze movements and augmented reality in bionics can widen the control bandwidth of prosthetic hand. With the help of i-MYO, the subjects can control a prosthetic hand using six grasp types if they can manipulate two muscle signals and gaze movement.

Value of the short time inversion recovery sequence of magnetic resonance imaging in the staging of Klippel-Trenaunay syndrome complicated with lymphedema

ObjectiveCurrently, the focus on limb lymphedema (LE) is on classification and staging. However, few scholars have conducted staging for Klippel-Trenaunay syndrome complicated LE (KTS-LE). This study aimed to investigate the value of the short time inversion recovery sequence of magnetic resonance imaging (MRI) in the staging of KTS-LE. MethodsForty-six patients who were diagnosed with KTS-LE were recruited for this retrospective study from July 2011 to November 2022. Referring to the clinical staging standard of lower extremity LE of the International Society of Lymphology in 2020, all patients were divided into three groups: stages I, II, and III. The MRI indicators of the three groups were recorded and statistically compared: LE range (unilateral bilateral, lower limbs, only thighs, only calves and ankles), abnormal parts (skin thickening, abnormal subcutaneous fat signal, abnormal muscle signal, muscle hypertrophy or contraction, abnormal bone signal, hyperostosis), and subcutaneous soft tissue signs (parallel line sign, grid sign, band sign, honeycomb sign, lymph lake sign, crescent sign, and nebula sign). ResultsThere was a significant difference in the honeycomb sign among the three periods (P = .028). There was a significant difference between stage II and stage I disease (P < .05). There was a significant difference between stage II and stage III disease (P < .05). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the honeycomb sign in diagnosing KTS-LE of stage II were 87.5%, 63.2%, 33.3%, 96.0%, and 67.4%, respectively. In contrast, the other signs were not statistically significant among the three periods. ConclusionsThe short time inversion recovery sequence of MRI is of great value in KTS-LE. The honeycomb sign is an important imaging indicator for the diagnosis of stage II disease. It is necessary to evaluate the severity of edema with MRI for KTS-LE, which is very important for therapeutic options.