Spinal cord injury necessitates effective rehabilitation strategies, with exercise therapies showing promise in promoting recovery. This study investigated the impact of rehabilitation exercise on functional recovery ...Spinal cord injury necessitates effective rehabilitation strategies, with exercise therapies showing promise in promoting recovery. This study investigated the impact of rehabilitation exercise on functional recovery and morphological changes following thoracic contusive spinal cord injury. After a 7-day recovery period after spinal cord injury, mice were assigned to either a trained group(10 weeks of voluntary running wheel or forced treadmill exercise) or an untrained group. Bi-weekly assessments revealed that the exercise-trained group, particularly the voluntary wheel exercise subgroup, displayed significantly improved locomotor recovery, more plasticity of dopaminergic and serotonin modulation compared with the untrained group. Additionally, exercise interventions led to gait pattern restoration and enhanced transcranial magnetic motor-evoked potentials. Despite consistent injury areas across groups, exercise training promoted terminal innervation of descending axons. In summary, voluntary wheel exercise shows promise for enhancing outcomes after thoracic contusive spinal cord injury, emphasizing the role of exercise modality in promoting recovery and morphological changes in spinal cord injuries. Our findings will influence future strategies for rehabilitation exercises, restoring functional movement after spinal cord injury.展开更多
Switched Reluctance Motors(SRMs),outfitted with rugged construction,good speed range,high torque density,and rare earth-free nature that outweigh induction motors(IM)and permanent magnet synchronous motor(PMSM),afford...Switched Reluctance Motors(SRMs),outfitted with rugged construction,good speed range,high torque density,and rare earth-free nature that outweigh induction motors(IM)and permanent magnet synchronous motor(PMSM),afford a broad range of applications in the domain of electric vehicles(EVs).Standard copper magnetic wire and low-carbon steel laminations are used to construct SRMs,which give them high efficiency in the range of 85-95%.Despite SRM's desirable features over traditional motor-speed drives,high torque ripples and radial distortions constrain their deployment in EVs.Precise rotor position is imperative for effective management of the speed and torque of SRMs.This paper provides an illustrative compendium on review of the torque-speed control and ripple mitigation techniques using design enhancements and control methods for SRM drives for EV applications.The various schemes were evaluated on their performance metricsoperational speed range,control complexity,practical realization,need for pre-stored parameters(look-up tables of current,inductance and torque profiles)and motor controller memory requirements.The findings provide valuable insights into balancing the gains and trade-offs associated with EV applications.Furthermore,they pinpoint opportunities for enhancement by analyzing the cost and technical aspects of different SRM controllers.展开更多
Model predictive control(MPC)has been deemed as an attractive control method in motor drives by virtue of its simple structure,convenient multi-objective optimization,and satisfactory dynamic performance.However,the s...Model predictive control(MPC)has been deemed as an attractive control method in motor drives by virtue of its simple structure,convenient multi-objective optimization,and satisfactory dynamic performance.However,the strong reliance on mathematical models seriously restrains its practical application.Therefore,improving the robustness of MPC has attained significant attentions in the last two decades,followed by which,model-free predictive control(MFPC)comes into existence.This article aims to reveal the current state of MFPC strategies for motor drives and give the categorization from the perspective of implementation.Based on this review,the principles of the reported MFPC strategies are introduced in detail,as well as the challenges encountered in technology realization.In addition,some of typical and important concepts are experimentally validated via case studies to evaluate the performance and highlight their features.Finally,the future trends of MFPC are discussed based on the current state and reported developments.展开更多
Attempts have been made to modulate motor sequence learning(MSL)through repetitive transcranial magnetic stimulation,targeting different sites within the sensorimotor network.However,the target with the optimum modula...Attempts have been made to modulate motor sequence learning(MSL)through repetitive transcranial magnetic stimulation,targeting different sites within the sensorimotor network.However,the target with the optimum modulatory effect on neural plasticity associated with MSL remains unclarified.This study was therefore designed to compare the role of the left primary motor cortex and the left supplementary motor area proper(SMAp)in modulating MSL across different complexity levels and for both hands,as well as the associated neuroplasticity by applying intermittent theta burst stimulation together with the electroencephalogram and concurrent transcranial magnetic stimulation.Our data demonstrated the role of SMAp stimulation in modulating neural communication to support MSL,which is achieved by facilitating regional activation and orchestrating neural coupling across distributed brain regions,particularly in interhemispheric connections.These findings may have important clinical implications,particularly for motor rehabilitation in populations such as post-stroke patients.展开更多
Permanent magnet synchronous motor(PMSM),known for their compact size and high-power density,is widely used in fields such as electric vehicles and servo drives.However,traditional PID control methods for PMSM cannot ...Permanent magnet synchronous motor(PMSM),known for their compact size and high-power density,is widely used in fields such as electric vehicles and servo drives.However,traditional PID control methods for PMSM cannot dynamically adjust parameters according to varying operating conditions.To address this issue,this paper proposes a PID control method based on a radial basis function(RBF)neural network,which adaptively tunes the PID controller parameters.First,an offline RBF neural network with optimal structural parameters is trained using the current and speed data of the PMSM,and then employed to construct the RBF-PID controller.During online training,the Jacobian information calculated via the RBF neural network is used to adaptively adjust the PID parameters.Simultaneously,the structural parameters of the RBF network are updated in reverse based on the error between the predicted and reference speed values.Finally,numerical simulations and experiments in the context of electric vehicle drive control show that the maximum speed errors of the SMC controller and the RBF-PID controller are 1.97 km/h and 0.17 km/h,respectively.Moreover,the RBF-PID controller outperforms both the SMC and traditional PID controllers in handling sudden speed changes.展开更多
The arc-linear motor(ALM) is a new type of special motor derived from the linear motor, which has the merits of high torque, compact structure and fast dynamic response. This kind of motor does not need a complex inte...The arc-linear motor(ALM) is a new type of special motor derived from the linear motor, which has the merits of high torque, compact structure and fast dynamic response. This kind of motor does not need a complex intermediate transmission device, it is used in some direct-drive applications for continuous rotation or limited angle motion. However, there is no systematic summary and generalization of the ALMs so far.Therefore, this paper systematically overviews the recent advances in ALMs for direct-drive systems. First, the evolution process and basic structure of the ALM are introduced. And then, various ALMs are reviewed with particular reference to motor topologies, working principle, motor performance,optimization design and control techniques. To heel, a comprehensive comparison of several typical ALMs is carried out. Finally, the application areas, main challenges and development trends of the ALMs are highlighted.展开更多
Amyotrophic lateral sclerosis is a rare neurodegenerative disease characterized by the involvement of both upper and lower motor neurons.Early bilateral limb involvement significantly affects patients'daily lives ...Amyotrophic lateral sclerosis is a rare neurodegenerative disease characterized by the involvement of both upper and lower motor neurons.Early bilateral limb involvement significantly affects patients'daily lives and may lead them to be confined to bed.However,the effect of upper and lower motor neuron impairment and other risk factors on bilateral limb involvement is unclear.To address this issue,we retrospectively collected data from 586 amyotrophic lateral sclerosis patients with limb onset diagnosed at Peking University Third Hospital between January 2020 and May 2022.A univariate analysis revealed no significant differences in the time intervals of spread in different directions between individuals with upper motor neuron-dominant amyotrophic lateral sclerosis and those with classic amyotrophic lateral sclerosis.We used causal directed acyclic graphs for risk factor determination and Cox proportional hazards models to investigate the association between the duration of bilateral limb involvement and clinical baseline characteristics in amyotrophic lateral sclerosis patients.Multiple factor analyses revealed that higher upper motor neuron scores(hazard ratio[HR]=1.05,95%confidence interval[CI]=1.01–1.09,P=0.018),onset in the left limb(HR=0.72,95%CI=0.58–0.89,P=0.002),and a horizontal pattern of progression(HR=0.46,95%CI=0.37–0.58,P<0.001)were risk factors for a shorter interval until bilateral limb involvement.The results demonstrated that a greater degree of upper motor neuron involvement might cause contralateral limb involvement to progress more quickly in limb-onset amyotrophic lateral sclerosis patients.These findings may improve the management of amyotrophic lateral sclerosis patients with limb onset and the prediction of patient prognosis.展开更多
Dear Editor,The primary motor cortex,also known as MOp in rodents,F1,or M1 in primates[1],plays a crucial role in autonomous motor control.It is interconnected with other motor control structures such as the basal gan...Dear Editor,The primary motor cortex,also known as MOp in rodents,F1,or M1 in primates[1],plays a crucial role in autonomous motor control.It is interconnected with other motor control structures such as the basal ganglia,thalamus,and brainstem.Among these connections,the corticostriatal system plays a significant role in functions including action selection,motor control,sequence learning,and habit formation[2].展开更多
Motor neuron diseases are sporadic or inherited fatal neurodegenerative conditions.They selectively affect the upper and/or lower motor neurons in the brain and spinal cord and feature a slow onset and a subacute cour...Motor neuron diseases are sporadic or inherited fatal neurodegenerative conditions.They selectively affect the upper and/or lower motor neurons in the brain and spinal cord and feature a slow onset and a subacute course contingent upon the site of damage.The main types include amyotrophic lateral sclerosis,progressive muscular atrophy,primary lateral sclerosis,and progressive bulbar palsy,the pathological processes of which are largely identical,with the main disparity lying in the location of the lesions.Amyotrophic lateral sclerosis is the representative condition in this group of diseases,while other types are its variants.Hence,this article mainly focuses on the advancements and challenges in drug research for amyotrophic lateral sclerosis but also briefly addresses several other important degenerative motor neuron diseases.Although the precise pathogenesis remains elusive,recent advancements have shed light on various theories,including gene mutation,excitatory amino acid toxicity,autoimmunology,and neurotrophic factors.The US Food and Drug Administration has approved four drugs for use in delaying the progression of amyotrophic lateral sclerosis:riluzole,edaravone,AMX0035,and tofersen,with the latter being the most recent to receive approval.However,following several phaseⅢtrials that failed to yield favorable outcomes,AMX0035 has been voluntarily withdrawn from both the US and Canadian markets.This article presents a comprehensive summary of drug trials primarily completed between January 1,2023,and June 30,2024,based on data sourced from clinicaltrials.gov.Among these trials,five are currently in phaseⅠ,seventeen are in phaseⅡ,and eleven are undergoing phaseⅢevaluation.Notably,24 clinical trials are now investigating potential disease-modifying therapy drugs,accounting for the majority of the drugs included in this review.Some promising drugs being investigated in preclinical studies,such as ATH-1105,are included in our analysis,and another review in frontiers in gene therapy and immunotherapy has demonstrated their therapeutic potential for motor neuron diseases.This article was written to be an overview of research trends and treatment prospects related to motor neuron disease drugs,with the aim of highlighting the latest potentialities for clinical therapy.展开更多
Intracellular transports of cargoes are performed by biological molecular motors that move processively along their linear tracks.In some cases,the cargo can interact with the track.A typical example of these cases is...Intracellular transports of cargoes are performed by biological molecular motors that move processively along their linear tracks.In some cases,the cargo can interact with the track.A typical example of these cases is the transport of a major mitotic signaling module,the chromosomal passenger complex(CPC),along the microtubule toward the equatorial cortex by a kinesin-6 motor during anaphase,where the CPC can interact with the microtubule.Here,an analytical theory is presented on the dynamics of the molecular motor transporting a track-interacted cargo.The theory is then applied to the transport of the track-interacted cargo by kinesin-6 and by kinesin-1 motors,with the theoretical results reproducing quantitatively the available experimental data.It is found that a diffusive cargo along the track,with the diffusion constant≥0.1μm2s-1,can largely enhance the processivity relative to the non-diffusive cargo and relative to the cargo having no interaction with the track.展开更多
A brain-computer interface(BCI)based on motor imagery(MI)provides additional control pathways by decoding the intentions of the brain.MI ability has great intra-individual variability,and the majority of MI-BCI system...A brain-computer interface(BCI)based on motor imagery(MI)provides additional control pathways by decoding the intentions of the brain.MI ability has great intra-individual variability,and the majority of MI-BCI systems are unable to adapt to this variability,leading to poor training effects.Therefore,prediction of MI ability is needed.In this study,we propose an MI ability predictor based on multi-frequency EEG features.To validate the performance of the predictor,a video-guided paradigm and a traditional MI paradigm are designed,and the predictor is applied to both paradigms.The results demonstrate that all subjects achieved>85%prediction precision in both applications,with a maximum of 96%.This study indicates that the predictor can accurately predict the individuals’MI ability in different states,provide the scientific basis for personalized training,and enhance the effect of MI-BCI training.展开更多
Background:Acupuncture is widely used in modulating brain excitability and motor function,as a form of complementary and alternative medicine.However,there is no existing meta-analysis evaluating the effectiveness and...Background:Acupuncture is widely used in modulating brain excitability and motor function,as a form of complementary and alternative medicine.However,there is no existing meta-analysis evaluating the effectiveness and safety of acupuncture on corticospinal excitability(CSE),and the credibility of the evidence has yet to be quantified.Objective:This study was designed to assess the efficacy and safety of electroacupuncture(EA)and manual acupuncture(MA)in enhancing brain excitability,specifically focusing on CSE as measured by transcranial magnetic stimulation(TMS).Search strategy:This study followed a systematic approach,searching 9 databases up to August 2024 and examining grey literature,in compliance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.Inclusion criteria:Studies were included if they compared the clinical efficacy of EA or MA with sham acupuncture,no treatment or usual training.Data extraction and analysis:Three investigators independently conducted literature screening,data extraction,and risk of bias assessment.The primary outcome focused on motor-evoked potentials as measured by TMS,with treatment effects quantified using mean differences or standardized mean differences between pre-and post-treatment.Subgroup analyses were conducted using mixed-effects models,while random-effects or fixed-effects models were used to estimate average treatment differences across studies.Results:Based on 34 studies involving 1031 adults,acupuncture techniques significantly enhanced CSE.EA had a greater impact than MA,with effect sizes of 0.53 mV vs 0.43 mV(95%confidence interval[CI]:[0.30,0.76],P<0.00001 vs 95%CI:[0.28,0.59],P<0.00001).The 5 most frequently used acupoints were LI4(Hegu,32 times),ST36(Zusanli,10 times),LI11(Quchi,7 times),TE5(Waiguan,6 times),and GB34(Yanglingquan,5 times).Conclusion:This systematic review indicates that both EA and MA could effectively and safely enhance CSE,bringing the corticospinal pathway closer to the threshold for firing,which may ultimately improve motor function.LI4,ST36,LI11,TE5 and GB34 are the most commonly used acupoints.展开更多
Missing data handling is vital for multi-sensor information fusion fault diagnosis of motors to prevent the accuracy decay or even model failure,and some promising results have been gained in several current studies.T...Missing data handling is vital for multi-sensor information fusion fault diagnosis of motors to prevent the accuracy decay or even model failure,and some promising results have been gained in several current studies.These studies,however,have the following limitations:1)effective supervision is neglected for missing data across different fault types and 2)imbalance in missing rates among fault types results in inadequate learning during model training.To overcome the above limitations,this paper proposes a dynamic relative advantagedriven multi-fault synergistic diagnosis method to accomplish accurate fault diagnosis of motors under imbalanced missing data rates.Firstly,a cross-fault-type generalized synergistic diagnostic strategy is established based on variational information bottleneck theory,which is able to ensure sufficient supervision in handling missing data.Then,a dynamic relative advantage assessment technique is designed to reduce diagnostic accuracy decay caused by imbalanced missing data rates.The proposed method is validated using multi-sensor data from motor fault simulation experiments,and experimental results demonstrate its effectiveness and superiority in improving diagnostic accuracy and generalization under imbalanced missing data rates.展开更多
Pyrrolizidine alkaloids(PAs)are natural toxins generated as secondarymetabolites in plants,predominantly consisting of unsaturated PAs with diverse toxicities,such as hepatotoxicity.Echimidine,a prominent PA,is believ...Pyrrolizidine alkaloids(PAs)are natural toxins generated as secondarymetabolites in plants,predominantly consisting of unsaturated PAs with diverse toxicities,such as hepatotoxicity.Echimidine,a prominent PA,is believed to exert various toxicological effects,including survival inhibition and induction of apoptosis of hepatocytes.However,the effects of echimidine on development remain unclear.We selected three concentrations of 0.02,0.2,and 2 mg/L to investigate the developmental toxicity of echimidine on zebrafish embryos.After a 7-day exposure,we observed hyperactivity and anxiety-like behavior in zebrafish larvae.Furthermore,we found that echimidine exposure significantly promoted embryonic motor neurodevelopment in geneticallymodified zebrafish.Next,we detected that echimidine exposure significantly increased the content of the excitatory neurotransmitter acetylcholine(ACh),accompanied by a significant decrease in acetylcholinesterase(AChE)activity.Conversely,echimidine led to a significant reduction in the content of the sedative neurotransmitterγ-aminobutyric acid(GABA),accompanied by abnormal gene expression of enzymes related to GABA synthesis.Moreover,we elucidated the strong direct binding of echimidine to zebrafish and human AChE protein through molecular docking.In summary,our study found that echimidine induced ACh accumulation possibly by inhibiting AChE activity,leading to motor neurodevelopmental abnormalities and hyperactivity in zebrafish larvae.This work provides important scientific knowledge on the effects and mechanisms of PAs on neural development,which is helpful for controlling the risk of PAs in food and protecting public health.展开更多
Stroke is a leading cause of death and disability worldwide,significantly impairing motor and cognitive functions.Effective rehabilitation is often hindered by the heterogeneity of stroke lesions,variability in recove...Stroke is a leading cause of death and disability worldwide,significantly impairing motor and cognitive functions.Effective rehabilitation is often hindered by the heterogeneity of stroke lesions,variability in recovery patterns,and the complexity of electroencephalography(EEG)signals,which are often contaminated by artifacts.Accurate classification of motor imagery(MI)tasks,involving the mental simulation of movements,is crucial for assessing rehabilitation strategies but is challenged by overlapping neural signatures and patient-specific variability.To address these challenges,this study introduces a graph-attentive convolutional long short-term memory(LSTM)network(GACL-Net),a novel hybrid deep learning model designed to improve MI classification accuracy and robustness.GACL-Net incorporates multi-scale convolutional blocks for spatial feature extraction,attention fusion layers for adaptive feature prioritization,graph convolutional layers to model inter-channel dependencies,and bidi-rectional LSTM layers with attention to capture temporal dynamics.Evaluated on an open-source EEG dataset of 50 acute stroke patients performing left and right MI tasks,GACL-Net achieved 99.52%classification accuracy and 97.43%generalization accuracy under leave-one-subject-out cross-validation,outperforming existing state-of-the-art methods.Additionally,its real-time processing capability,with prediction times of 33–56 ms on a T4 GPU,underscores its clinical potential for real-time neurofeedback and adaptive rehabilitation.These findings highlight the model’s potential for clinical applications in assessing rehabilitation effectiveness and optimizing therapy plans through precise MI classification.展开更多
This paper presents the design of a novel resonator for use in a piezoelectric linear ultrasonic motor.the work is motivated by a motor previously developed by the authors that showed to be capable of achieving a forc...This paper presents the design of a novel resonator for use in a piezoelectric linear ultrasonic motor.the work is motivated by a motor previously developed by the authors that showed to be capable of achieving a force of 50 mn and a velocity of 14 mm/s,which they found unsatisfactory.to that end,among an existing variety of working principles for piezoelectric ultrasonic motors,the principle of giving the material points of the stator in contact with the rotor a“∞”trajectory and thus propelling the rotor was utilized.our concept is based on Euler-Bernoulli beam theory which shows that the natural frequency ratio of the first and second bending modes for a beam,fixed at both ends,is approximately 3 and we employ a gradient-based optimization algorithm to assist in the design of the structure.展开更多
Sensorless control of switched reluctance motors(SRMs) often requires a hybrid mode combining low-speed pulse injection methods and high-speed model-based estimation.However,pulse injection causes unwanted audible noi...Sensorless control of switched reluctance motors(SRMs) often requires a hybrid mode combining low-speed pulse injection methods and high-speed model-based estimation.However,pulse injection causes unwanted audible noises and torque ripples.This article proposes an enhanced model-based sensorless approach to extend downwards the speed range in which sensorless control can work without injection.An inertial phase-locked loop (IPLL) based on a stator flux observer is introduced for position estimation.Compared to the conventional phase-locked loop scheme,the IPLL offers a more robust disturbance rejection capability and thus reduces the flux model errors at lower speeds.Experimental results substantiate the feasibility of the extended low-speed operation using the model-based sensorless control approach.展开更多
In this paper,a 12/14-pole permanent magnet in-wheel motor is studied for potential in-wheel application,and the torque and loss are improved simultaneously based on designing and optimizing the corresponding dominant...In this paper,a 12/14-pole permanent magnet in-wheel motor is studied for potential in-wheel application,and the torque and loss are improved simultaneously based on designing and optimizing the corresponding dominant harmonics.The key of this study is to evaluate the contributions of harmonics on torque and loss,and further determines the harmonics related to them.Based on this,the torque enhancement factor and loss suppression factor are defined based on the selected dominant harmonics.And,the two factors are set as the optimization objectives,aiming at improving the characteristics of torque and loss.At the same time,to achieve an efficient optimization,a layered optimization method is presented,which includes magnet source layer and permeance layer.Based on the optimization,the motor torque is improved effectively,while the rotor iron loss is also reduced significantly.Then,a prototype motor is manufactured for experimental test.Finally,the simulation analysis and test results verify the validation of the studied motor and the proposed optimization method based on dominant harmonics.展开更多
Objective: To investigate the effect of a self-developed balance rhythm dance program on the rehabilitation of motor function and the reduction of fall risk in elderly women with diminished balance function. Methods: ...Objective: To investigate the effect of a self-developed balance rhythm dance program on the rehabilitation of motor function and the reduction of fall risk in elderly women with diminished balance function. Methods: Fifty elderly women with reduced balance function, admitted to the Qingbar Elderly Care Center of Chongqing Medical University from December 2022 to December 2023, were randomly selected and divided into two groups. The aerobic exercise group (25 patients) received traditional treatment and rehabilitation nursing, while the balance rhythm dance intervention group (25 patients) received the balance rhythm dance intervention in addition to traditional treatment and rehabilitation nursing. The Unified Parkinson’s Disease Rating Scale (UPDRS) and Berg Balance Scale (BBS) were used as evaluation indicators to compare the intervention effects between the two groups. Results: The data revealed that the balance rhythm dance intervention significantly improved the motor ability and balance function of elderly women in the intervention group (P < 0.01), with statistically significant differences observed. Conclusion: The balance rhythm dance program plays a critical role in promoting the rehabilitation of motor function and balance ability in elderly women, effectively enhancing their quality of life.展开更多
基金supported by the NIH (R01NS103481, R01NS111776, and R01NS131489)Indiana Department of Health (ISDH58180)(all to WW)。
文摘Spinal cord injury necessitates effective rehabilitation strategies, with exercise therapies showing promise in promoting recovery. This study investigated the impact of rehabilitation exercise on functional recovery and morphological changes following thoracic contusive spinal cord injury. After a 7-day recovery period after spinal cord injury, mice were assigned to either a trained group(10 weeks of voluntary running wheel or forced treadmill exercise) or an untrained group. Bi-weekly assessments revealed that the exercise-trained group, particularly the voluntary wheel exercise subgroup, displayed significantly improved locomotor recovery, more plasticity of dopaminergic and serotonin modulation compared with the untrained group. Additionally, exercise interventions led to gait pattern restoration and enhanced transcranial magnetic motor-evoked potentials. Despite consistent injury areas across groups, exercise training promoted terminal innervation of descending axons. In summary, voluntary wheel exercise shows promise for enhancing outcomes after thoracic contusive spinal cord injury, emphasizing the role of exercise modality in promoting recovery and morphological changes in spinal cord injuries. Our findings will influence future strategies for rehabilitation exercises, restoring functional movement after spinal cord injury.
基金supported in part by the Universitat Politècnica de València under grant PAID-10-21supported through AMRITA Seed Grant(Proposal ID:ASG2022188)。
文摘Switched Reluctance Motors(SRMs),outfitted with rugged construction,good speed range,high torque density,and rare earth-free nature that outweigh induction motors(IM)and permanent magnet synchronous motor(PMSM),afford a broad range of applications in the domain of electric vehicles(EVs).Standard copper magnetic wire and low-carbon steel laminations are used to construct SRMs,which give them high efficiency in the range of 85-95%.Despite SRM's desirable features over traditional motor-speed drives,high torque ripples and radial distortions constrain their deployment in EVs.Precise rotor position is imperative for effective management of the speed and torque of SRMs.This paper provides an illustrative compendium on review of the torque-speed control and ripple mitigation techniques using design enhancements and control methods for SRM drives for EV applications.The various schemes were evaluated on their performance metricsoperational speed range,control complexity,practical realization,need for pre-stored parameters(look-up tables of current,inductance and torque profiles)and motor controller memory requirements.The findings provide valuable insights into balancing the gains and trade-offs associated with EV applications.Furthermore,they pinpoint opportunities for enhancement by analyzing the cost and technical aspects of different SRM controllers.
基金supported in part by the National Natural Science Foundation of China under Grant 52077002。
文摘Model predictive control(MPC)has been deemed as an attractive control method in motor drives by virtue of its simple structure,convenient multi-objective optimization,and satisfactory dynamic performance.However,the strong reliance on mathematical models seriously restrains its practical application.Therefore,improving the robustness of MPC has attained significant attentions in the last two decades,followed by which,model-free predictive control(MFPC)comes into existence.This article aims to reveal the current state of MFPC strategies for motor drives and give the categorization from the perspective of implementation.Based on this review,the principles of the reported MFPC strategies are introduced in detail,as well as the challenges encountered in technology realization.In addition,some of typical and important concepts are experimentally validated via case studies to evaluate the performance and highlight their features.Finally,the future trends of MFPC are discussed based on the current state and reported developments.
基金supported by grants from the Zhejiang Provincial Natural Science Foundation(LGJ22H180001)Zhejiang Medical and Health Science and Technology Project(2021KY249)the National Key R&D Program of China(2017YFC1310000).
文摘Attempts have been made to modulate motor sequence learning(MSL)through repetitive transcranial magnetic stimulation,targeting different sites within the sensorimotor network.However,the target with the optimum modulatory effect on neural plasticity associated with MSL remains unclarified.This study was therefore designed to compare the role of the left primary motor cortex and the left supplementary motor area proper(SMAp)in modulating MSL across different complexity levels and for both hands,as well as the associated neuroplasticity by applying intermittent theta burst stimulation together with the electroencephalogram and concurrent transcranial magnetic stimulation.Our data demonstrated the role of SMAp stimulation in modulating neural communication to support MSL,which is achieved by facilitating regional activation and orchestrating neural coupling across distributed brain regions,particularly in interhemispheric connections.These findings may have important clinical implications,particularly for motor rehabilitation in populations such as post-stroke patients.
文摘Permanent magnet synchronous motor(PMSM),known for their compact size and high-power density,is widely used in fields such as electric vehicles and servo drives.However,traditional PID control methods for PMSM cannot dynamically adjust parameters according to varying operating conditions.To address this issue,this paper proposes a PID control method based on a radial basis function(RBF)neural network,which adaptively tunes the PID controller parameters.First,an offline RBF neural network with optimal structural parameters is trained using the current and speed data of the PMSM,and then employed to construct the RBF-PID controller.During online training,the Jacobian information calculated via the RBF neural network is used to adaptively adjust the PID parameters.Simultaneously,the structural parameters of the RBF network are updated in reverse based on the error between the predicted and reference speed values.Finally,numerical simulations and experiments in the context of electric vehicle drive control show that the maximum speed errors of the SMC controller and the RBF-PID controller are 1.97 km/h and 0.17 km/h,respectively.Moreover,the RBF-PID controller outperforms both the SMC and traditional PID controllers in handling sudden speed changes.
基金supported in part by the National Natural Science Foundation of China under Grants 52307049 and U23A20644in part by the Fundamental Research Funds for the Central Universities under Grant JZ2023HGTB0243+1 种基金in part by the Key Laboratory of Electric Drive and Control of Anhui Province under Grant DQKJ202403in part by the China Postdoctoral Science Foundation under Grant 2024M751073。
文摘The arc-linear motor(ALM) is a new type of special motor derived from the linear motor, which has the merits of high torque, compact structure and fast dynamic response. This kind of motor does not need a complex intermediate transmission device, it is used in some direct-drive applications for continuous rotation or limited angle motion. However, there is no systematic summary and generalization of the ALMs so far.Therefore, this paper systematically overviews the recent advances in ALMs for direct-drive systems. First, the evolution process and basic structure of the ALM are introduced. And then, various ALMs are reviewed with particular reference to motor topologies, working principle, motor performance,optimization design and control techniques. To heel, a comprehensive comparison of several typical ALMs is carried out. Finally, the application areas, main challenges and development trends of the ALMs are highlighted.
基金supported by the National Natural Science Foundation of China,Nos.82071426,81873784Clinical Cohort Construction Program of Peking University Third Hospital,No.BYSYDL2019002(all to DF)。
文摘Amyotrophic lateral sclerosis is a rare neurodegenerative disease characterized by the involvement of both upper and lower motor neurons.Early bilateral limb involvement significantly affects patients'daily lives and may lead them to be confined to bed.However,the effect of upper and lower motor neuron impairment and other risk factors on bilateral limb involvement is unclear.To address this issue,we retrospectively collected data from 586 amyotrophic lateral sclerosis patients with limb onset diagnosed at Peking University Third Hospital between January 2020 and May 2022.A univariate analysis revealed no significant differences in the time intervals of spread in different directions between individuals with upper motor neuron-dominant amyotrophic lateral sclerosis and those with classic amyotrophic lateral sclerosis.We used causal directed acyclic graphs for risk factor determination and Cox proportional hazards models to investigate the association between the duration of bilateral limb involvement and clinical baseline characteristics in amyotrophic lateral sclerosis patients.Multiple factor analyses revealed that higher upper motor neuron scores(hazard ratio[HR]=1.05,95%confidence interval[CI]=1.01–1.09,P=0.018),onset in the left limb(HR=0.72,95%CI=0.58–0.89,P=0.002),and a horizontal pattern of progression(HR=0.46,95%CI=0.37–0.58,P<0.001)were risk factors for a shorter interval until bilateral limb involvement.The results demonstrated that a greater degree of upper motor neuron involvement might cause contralateral limb involvement to progress more quickly in limb-onset amyotrophic lateral sclerosis patients.These findings may improve the management of amyotrophic lateral sclerosis patients with limb onset and the prediction of patient prognosis.
基金supported by the National Key R&D Program of China(2020YFE0205900 and 2022YEF0203200)the STI 2030-Major Project(2021ZD0200104 and 2022ZD0205203)+2 种基金the Shenzhen Science and Technology Program(RCYX20210706092100003,RCBS20221008093311027,and JCYJ20210324102006018)the Youth Innovation Promotion Association CAS(2022367)the Shenzhen Technological Research Center for Primate Translational Medicine grant(XMHT20220104005).
文摘Dear Editor,The primary motor cortex,also known as MOp in rodents,F1,or M1 in primates[1],plays a crucial role in autonomous motor control.It is interconnected with other motor control structures such as the basal ganglia,thalamus,and brainstem.Among these connections,the corticostriatal system plays a significant role in functions including action selection,motor control,sequence learning,and habit formation[2].
基金supported by the National Key Research and Development Program of China,No.2022YFC2703101(to YC)the National Natural Science Fundation of China,No.82371422(to YC)+1 种基金the National Innovation and Entrepreneurship Training Program for College Students,No.202310611408(to XW)the 1·3·5 Project for Disciplines of Excellence Clinical Research Fund,West China Hospital,Sichuan University,No.2023HXFH032(to YC)。
文摘Motor neuron diseases are sporadic or inherited fatal neurodegenerative conditions.They selectively affect the upper and/or lower motor neurons in the brain and spinal cord and feature a slow onset and a subacute course contingent upon the site of damage.The main types include amyotrophic lateral sclerosis,progressive muscular atrophy,primary lateral sclerosis,and progressive bulbar palsy,the pathological processes of which are largely identical,with the main disparity lying in the location of the lesions.Amyotrophic lateral sclerosis is the representative condition in this group of diseases,while other types are its variants.Hence,this article mainly focuses on the advancements and challenges in drug research for amyotrophic lateral sclerosis but also briefly addresses several other important degenerative motor neuron diseases.Although the precise pathogenesis remains elusive,recent advancements have shed light on various theories,including gene mutation,excitatory amino acid toxicity,autoimmunology,and neurotrophic factors.The US Food and Drug Administration has approved four drugs for use in delaying the progression of amyotrophic lateral sclerosis:riluzole,edaravone,AMX0035,and tofersen,with the latter being the most recent to receive approval.However,following several phaseⅢtrials that failed to yield favorable outcomes,AMX0035 has been voluntarily withdrawn from both the US and Canadian markets.This article presents a comprehensive summary of drug trials primarily completed between January 1,2023,and June 30,2024,based on data sourced from clinicaltrials.gov.Among these trials,five are currently in phaseⅠ,seventeen are in phaseⅡ,and eleven are undergoing phaseⅢevaluation.Notably,24 clinical trials are now investigating potential disease-modifying therapy drugs,accounting for the majority of the drugs included in this review.Some promising drugs being investigated in preclinical studies,such as ATH-1105,are included in our analysis,and another review in frontiers in gene therapy and immunotherapy has demonstrated their therapeutic potential for motor neuron diseases.This article was written to be an overview of research trends and treatment prospects related to motor neuron disease drugs,with the aim of highlighting the latest potentialities for clinical therapy.
基金supported by the Youth Project of Science and Technology Research Program of Chongqing Education Commission of China(No.KJQN202404522)。
文摘Intracellular transports of cargoes are performed by biological molecular motors that move processively along their linear tracks.In some cases,the cargo can interact with the track.A typical example of these cases is the transport of a major mitotic signaling module,the chromosomal passenger complex(CPC),along the microtubule toward the equatorial cortex by a kinesin-6 motor during anaphase,where the CPC can interact with the microtubule.Here,an analytical theory is presented on the dynamics of the molecular motor transporting a track-interacted cargo.The theory is then applied to the transport of the track-interacted cargo by kinesin-6 and by kinesin-1 motors,with the theoretical results reproducing quantitatively the available experimental data.It is found that a diffusive cargo along the track,with the diffusion constant≥0.1μm2s-1,can largely enhance the processivity relative to the non-diffusive cargo and relative to the cargo having no interaction with the track.
基金supported by the Natural Science Foundation of Hebei Province(F2024202019)the National Natural Science Foundation of China(32201072).
文摘A brain-computer interface(BCI)based on motor imagery(MI)provides additional control pathways by decoding the intentions of the brain.MI ability has great intra-individual variability,and the majority of MI-BCI systems are unable to adapt to this variability,leading to poor training effects.Therefore,prediction of MI ability is needed.In this study,we propose an MI ability predictor based on multi-frequency EEG features.To validate the performance of the predictor,a video-guided paradigm and a traditional MI paradigm are designed,and the predictor is applied to both paradigms.The results demonstrate that all subjects achieved>85%prediction precision in both applications,with a maximum of 96%.This study indicates that the predictor can accurately predict the individuals’MI ability in different states,provide the scientific basis for personalized training,and enhance the effect of MI-BCI training.
文摘Background:Acupuncture is widely used in modulating brain excitability and motor function,as a form of complementary and alternative medicine.However,there is no existing meta-analysis evaluating the effectiveness and safety of acupuncture on corticospinal excitability(CSE),and the credibility of the evidence has yet to be quantified.Objective:This study was designed to assess the efficacy and safety of electroacupuncture(EA)and manual acupuncture(MA)in enhancing brain excitability,specifically focusing on CSE as measured by transcranial magnetic stimulation(TMS).Search strategy:This study followed a systematic approach,searching 9 databases up to August 2024 and examining grey literature,in compliance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.Inclusion criteria:Studies were included if they compared the clinical efficacy of EA or MA with sham acupuncture,no treatment or usual training.Data extraction and analysis:Three investigators independently conducted literature screening,data extraction,and risk of bias assessment.The primary outcome focused on motor-evoked potentials as measured by TMS,with treatment effects quantified using mean differences or standardized mean differences between pre-and post-treatment.Subgroup analyses were conducted using mixed-effects models,while random-effects or fixed-effects models were used to estimate average treatment differences across studies.Results:Based on 34 studies involving 1031 adults,acupuncture techniques significantly enhanced CSE.EA had a greater impact than MA,with effect sizes of 0.53 mV vs 0.43 mV(95%confidence interval[CI]:[0.30,0.76],P<0.00001 vs 95%CI:[0.28,0.59],P<0.00001).The 5 most frequently used acupoints were LI4(Hegu,32 times),ST36(Zusanli,10 times),LI11(Quchi,7 times),TE5(Waiguan,6 times),and GB34(Yanglingquan,5 times).Conclusion:This systematic review indicates that both EA and MA could effectively and safely enhance CSE,bringing the corticospinal pathway closer to the threshold for firing,which may ultimately improve motor function.LI4,ST36,LI11,TE5 and GB34 are the most commonly used acupoints.
文摘Missing data handling is vital for multi-sensor information fusion fault diagnosis of motors to prevent the accuracy decay or even model failure,and some promising results have been gained in several current studies.These studies,however,have the following limitations:1)effective supervision is neglected for missing data across different fault types and 2)imbalance in missing rates among fault types results in inadequate learning during model training.To overcome the above limitations,this paper proposes a dynamic relative advantagedriven multi-fault synergistic diagnosis method to accomplish accurate fault diagnosis of motors under imbalanced missing data rates.Firstly,a cross-fault-type generalized synergistic diagnostic strategy is established based on variational information bottleneck theory,which is able to ensure sufficient supervision in handling missing data.Then,a dynamic relative advantage assessment technique is designed to reduce diagnostic accuracy decay caused by imbalanced missing data rates.The proposed method is validated using multi-sensor data from motor fault simulation experiments,and experimental results demonstrate its effectiveness and superiority in improving diagnostic accuracy and generalization under imbalanced missing data rates.
基金supported by the Key Project at the Central Government Level:the ability establishment of sustainable use for valuable Chinese medicine resources(No.2060302)the National Natural Science Foundation of China(No.82104389)+2 种基金the Scientific and Technological Innovation Project of China Academy of Chinese Medical Sciences(No.CI2023E002)the High-level Key Discipline Program of National Administration of Traditional Chinese Medicine(No.ZYYZDXK-2023244)China Agricultural Research System of MOF and MARA(No.CARS-21).
文摘Pyrrolizidine alkaloids(PAs)are natural toxins generated as secondarymetabolites in plants,predominantly consisting of unsaturated PAs with diverse toxicities,such as hepatotoxicity.Echimidine,a prominent PA,is believed to exert various toxicological effects,including survival inhibition and induction of apoptosis of hepatocytes.However,the effects of echimidine on development remain unclear.We selected three concentrations of 0.02,0.2,and 2 mg/L to investigate the developmental toxicity of echimidine on zebrafish embryos.After a 7-day exposure,we observed hyperactivity and anxiety-like behavior in zebrafish larvae.Furthermore,we found that echimidine exposure significantly promoted embryonic motor neurodevelopment in geneticallymodified zebrafish.Next,we detected that echimidine exposure significantly increased the content of the excitatory neurotransmitter acetylcholine(ACh),accompanied by a significant decrease in acetylcholinesterase(AChE)activity.Conversely,echimidine led to a significant reduction in the content of the sedative neurotransmitterγ-aminobutyric acid(GABA),accompanied by abnormal gene expression of enzymes related to GABA synthesis.Moreover,we elucidated the strong direct binding of echimidine to zebrafish and human AChE protein through molecular docking.In summary,our study found that echimidine induced ACh accumulation possibly by inhibiting AChE activity,leading to motor neurodevelopmental abnormalities and hyperactivity in zebrafish larvae.This work provides important scientific knowledge on the effects and mechanisms of PAs on neural development,which is helpful for controlling the risk of PAs in food and protecting public health.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT under Grant NRF-2022R1A2C1005316.
文摘Stroke is a leading cause of death and disability worldwide,significantly impairing motor and cognitive functions.Effective rehabilitation is often hindered by the heterogeneity of stroke lesions,variability in recovery patterns,and the complexity of electroencephalography(EEG)signals,which are often contaminated by artifacts.Accurate classification of motor imagery(MI)tasks,involving the mental simulation of movements,is crucial for assessing rehabilitation strategies but is challenged by overlapping neural signatures and patient-specific variability.To address these challenges,this study introduces a graph-attentive convolutional long short-term memory(LSTM)network(GACL-Net),a novel hybrid deep learning model designed to improve MI classification accuracy and robustness.GACL-Net incorporates multi-scale convolutional blocks for spatial feature extraction,attention fusion layers for adaptive feature prioritization,graph convolutional layers to model inter-channel dependencies,and bidi-rectional LSTM layers with attention to capture temporal dynamics.Evaluated on an open-source EEG dataset of 50 acute stroke patients performing left and right MI tasks,GACL-Net achieved 99.52%classification accuracy and 97.43%generalization accuracy under leave-one-subject-out cross-validation,outperforming existing state-of-the-art methods.Additionally,its real-time processing capability,with prediction times of 33–56 ms on a T4 GPU,underscores its clinical potential for real-time neurofeedback and adaptive rehabilitation.These findings highlight the model’s potential for clinical applications in assessing rehabilitation effectiveness and optimizing therapy plans through precise MI classification.
文摘This paper presents the design of a novel resonator for use in a piezoelectric linear ultrasonic motor.the work is motivated by a motor previously developed by the authors that showed to be capable of achieving a force of 50 mn and a velocity of 14 mm/s,which they found unsatisfactory.to that end,among an existing variety of working principles for piezoelectric ultrasonic motors,the principle of giving the material points of the stator in contact with the rotor a“∞”trajectory and thus propelling the rotor was utilized.our concept is based on Euler-Bernoulli beam theory which shows that the natural frequency ratio of the first and second bending modes for a beam,fixed at both ends,is approximately 3 and we employ a gradient-based optimization algorithm to assist in the design of the structure.
基金supported in part by the National Natural Science Foundation of China 52307069in part by 2024 Tertiary Education Scientific Research Project of Guangzhou Municipal Education Bureau under Grant2024312176in part by the Project of Hetao Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone under Grant HZQB-KCZYB-2020083。
文摘Sensorless control of switched reluctance motors(SRMs) often requires a hybrid mode combining low-speed pulse injection methods and high-speed model-based estimation.However,pulse injection causes unwanted audible noises and torque ripples.This article proposes an enhanced model-based sensorless approach to extend downwards the speed range in which sensorless control can work without injection.An inertial phase-locked loop (IPLL) based on a stator flux observer is introduced for position estimation.Compared to the conventional phase-locked loop scheme,the IPLL offers a more robust disturbance rejection capability and thus reduces the flux model errors at lower speeds.Experimental results substantiate the feasibility of the extended low-speed operation using the model-based sensorless control approach.
文摘In this paper,a 12/14-pole permanent magnet in-wheel motor is studied for potential in-wheel application,and the torque and loss are improved simultaneously based on designing and optimizing the corresponding dominant harmonics.The key of this study is to evaluate the contributions of harmonics on torque and loss,and further determines the harmonics related to them.Based on this,the torque enhancement factor and loss suppression factor are defined based on the selected dominant harmonics.And,the two factors are set as the optimization objectives,aiming at improving the characteristics of torque and loss.At the same time,to achieve an efficient optimization,a layered optimization method is presented,which includes magnet source layer and permeance layer.Based on the optimization,the motor torque is improved effectively,while the rotor iron loss is also reduced significantly.Then,a prototype motor is manufactured for experimental test.Finally,the simulation analysis and test results verify the validation of the studied motor and the proposed optimization method based on dominant harmonics.
基金Chongqing Sports Scientific Research Project“Research and Development of Balance Rhythm Dance and Its Application in Reducing Fall Risk in Older Women”(Project No.D202209)Chongqing Nursing Vocational College College-level Project“Research on the Talent Training Model of Field Engineers in the Intelligent Health Care Sector Based on Rehabilitation Assistive Devices under the‘Integration of Science and Education’Approach”(Project No.Y202307)+1 种基金Chongqing Science and Technology Bureau Research Project“Investigating the Impact of Electro-acupuncture Applied to Antagonist Muscles on Walking Ability in Stroke Patients with Hemiplegia Based on the Principle of Reciprocal Inhibition”(Project No.CSTC2019JXJL130019)Chongqing Traditional Chinese Medicine Hospital Research Project“The Alterations in the Pelvic Floor Muscle Group Following Acupuncture Treatment for Postpartum Stress Urinary Incontinence Were Evaluated Using SWE Technology”(Project No.jxyn2021-2-23)。
文摘Objective: To investigate the effect of a self-developed balance rhythm dance program on the rehabilitation of motor function and the reduction of fall risk in elderly women with diminished balance function. Methods: Fifty elderly women with reduced balance function, admitted to the Qingbar Elderly Care Center of Chongqing Medical University from December 2022 to December 2023, were randomly selected and divided into two groups. The aerobic exercise group (25 patients) received traditional treatment and rehabilitation nursing, while the balance rhythm dance intervention group (25 patients) received the balance rhythm dance intervention in addition to traditional treatment and rehabilitation nursing. The Unified Parkinson’s Disease Rating Scale (UPDRS) and Berg Balance Scale (BBS) were used as evaluation indicators to compare the intervention effects between the two groups. Results: The data revealed that the balance rhythm dance intervention significantly improved the motor ability and balance function of elderly women in the intervention group (P < 0.01), with statistically significant differences observed. Conclusion: The balance rhythm dance program plays a critical role in promoting the rehabilitation of motor function and balance ability in elderly women, effectively enhancing their quality of life.
