Artificial facial nerve prostheses are thought to restore eye-closed function in peripheral facial paralysis patients.At present,however,there is no adequate quantitative or qualitative information regarding myoelectr...Artificial facial nerve prostheses are thought to restore eye-closed function in peripheral facial paralysis patients.At present,however,there is no adequate quantitative or qualitative information regarding myoelectric signal（MES）features for healthy orbiculads oculi muscle（OOM）.The present study analyzed MES features of normal OOM in rabbits during the natural continuous eye-opening（N1）state,natural continuous eye-closing（N2）state,natural blink（N3）state,and evoked eye-closing（E）state according to time domain and frequency domain analysis.Results showed that OOM electrical activities in N1 and N2 states,as well as myoelectric amplitude,were low and stable.Nevertheless,during N3 and E states,OOM electrical activities were significantly increased and amplitude was much higher in the E state than in the N3 state.In the time domain,differences in MES peak absolute potential were not significant between N1 and N2 states,in the frequency domain,differences in power spectral density peak frequency of electromyogram signals were significant between two sets of four OOM movement states.These results suggest that OOM significantly contracts and induces eyelid-closing action.In addition,OOM is diastolic during the N1state.A N2 state does not require continuous intensive OOM contraction.Moreover,distinctions of quantitative information in time and frequency domain features of MES can be used as an OOM reference to identify muscle movement patterns.展开更多
AIM： To explore the mechanism of the exciting effects of electro-acupuncture （EA） at Sibai on the gastric myoelectric activities. METHODS： A total of 32 rats were randomly divided into four groups. Through intrape...AIM： To explore the mechanism of the exciting effects of electro-acupuncture （EA） at Sibai on the gastric myoelectric activities. METHODS： A total of 32 rats were randomly divided into four groups. Through intraperitoneal injection with atropine （the anti-cholinergic agent by blockade of muscarinic receptors）, hexarnethonium （automatic nerve ganglion-blocking agent） and reserpine （anti-adrenergic agent by depleting the adrenergic nerve terminal of its norepinephrine store）, effects of EA at Sibai on the gastric myoelectric activities of the denervated rats were observed. RESULTS： After intraperitoneal injection of atropine and hexamethonium, the average amplitude and ratio of period to time in the phase of high activity of gastric myoelectric slow wave, and the average numbers of the peaks of gastric myoelectric fast wave were significantly decreased （P 〈 0.01, P 〈 0.05, P 〈 0.01）, while after intraperitoneal injection of reserpine, the aforementioned three parameters were increased （P 〈 0.01, P 〈 0.05, P 〈 0.01）. EA at Sibai point partially relieved the inhibitory effect of atropine and hexamethonium on the gastric myoelectric activities in the rats （P 〈 0.05 or P 〉 0.05）. CONCLUSION： Cholinergic and adrenergic nervous systems and autonomic nerve ganglion participate in the peripheral passage of the controlling effects of EA at Foot Yangming Channel on gastrointestinal tract.展开更多
AIM： To investigate the effects of entero-hepatic bile add circulation on the inter-digestive migrating myoelectrical complex （MMC） in rats. METHODS： Thirty-two rats were divided into four groups. Three pairs of b...AIM： To investigate the effects of entero-hepatic bile add circulation on the inter-digestive migrating myoelectrical complex （MMC） in rats. METHODS： Thirty-two rats were divided into four groups. Three pairs of bipolar silver electrodes were chronically implanted in the antrum, duodenum and jejunum. Three groups of Uhem were ligatecl around the upper part of common bile duct （CBD）. The experiments were performed in consdous and fasting state. The gastrointestinal myoelectrical activity was recorded. Ursodeoxycholic acid （UDCA） and saline were then perfused into stomachs of two groups with CBD obstruction and the effects of them on the MMC were observed. RESULTS： A typical pattern of MMC was observed in normal fasting rats. MMC of antral and duodenal origin disappeared temporarily in earlier stage of CBD obstruction. While MMC of jejunum origin appeared. increased MMC cycle duration was seen after 4 d in rats with CBD obstruction. The MMC after CBD obstruction was characterized by an increased duration of phase Ⅱ-like activity and decreased duration of phase Ⅰ ＆ Ⅲ activity. Perfusion into stomachs with UDCA resulted in a shorter MMC cycle duration and a longer duration of phase III of duodenal origin compared to the normal group. CONCLUSION： Entero-hepatic bile add drculation initiates inter-digestive MMC of duodenal origin.展开更多
Objective:To investigate the distribution of the motilin receptor in the amygdala of rats and its role in regulating the duodenal migrating myoelectric complex(MMC).Methods:The distribution of motilin receptor in the ...Objective:To investigate the distribution of the motilin receptor in the amygdala of rats and its role in regulating the duodenal migrating myoelectric complex(MMC).Methods:The distribution of motilin receptor in the amygdala in adult SD rats was detected by immunohistochemistry methods,and the duodenal interdigestive MMC was recorded via the electrodes implanted in the duodenum and analyzed us- ing a multichannel recorder.Results:Motilin receptor was observed in the amygdala of rats.The great amount of motilin receptor was found in the medial amygdaloid nucleus,which was also abundant in the basolateral nucleus but less abundant in the basomedial amygdaloid nucleus,the central amygdaloid nucle- us and the lateral amygdaloid nucleus.The shortening of the duodenal MMC cycle duration and the in- crease of the amplitude and the frequency of phase $ were recorded after motilin receptors being bound with exogenous motilin in the amygdala.The effects could be completely blocked by the subdiaphragmatic vagotomy but not by the intravenous injections of atropine,phentolamine or propranolol.Anti-motilin serum could partially block these effects,and the destruction of the basolateral nucleus of the amygdala had no significant effects on the duodenal MMC.Conclusion:Motilin receptor is present in all the subnu- clei of the amygdala,with the greatest amount of motilin receptor present in the medial amygdaloid nucle- us.Microinjections of motilin in the amygdala can shorten the duodenal MMC cycle duration and increase the amplitude and the frequency of phaseⅢ.These effects might be accomplished via the amygdala-hy- pothalamus-brainstem-vagus pathway,indicating the important role of the amygdala motilin receptor in the duodenal MMC regulation.展开更多
AIM: To evaluate the effect of age and acoustic stress on gastric myoelectrical activity (GMA) and autonomic nervous system function. METHODS: Twenty-one male subjects (age range 22-71 years, mean 44 years) were recru...AIM: To evaluate the effect of age and acoustic stress on gastric myoelectrical activity (GMA) and autonomic nervous system function. METHODS: Twenty-one male subjects (age range 22-71 years, mean 44 years) were recruited and exposed, in random order, to three auditory stimuli (Hospital noise, conversation babble and traffic noise) after a 20-min baseline. All periods lasted 20 min and were interspersed with a 10 min of recovery. GMA was obtained using a Synectics Microdigitrapper. Autonomic nerve function was assessed by monitoring blood pressure and heart rate using an automatic recording device. RESULTS: Dominant power tended to decrease with increase of age (P < 0.05). The overall percentage of three cycle per minute (CPM) activity decreased during exposure to hospital noise (12.0%, P < 0.05), traffic noise (13.9%, P < 0.05), and conversation babble (7.1%). The subjects in the younger group (< 50 years) showed a consistent reduction in the percentage of 3 CPM activity during hospital noise (22.9%, P < 0.05), traffic noise (19.0%, P < 0.05), and conversation babble (15.5%). These observations were accompanied by a significant increase in bradygastria: hospital noise (P < 0.05) and traffic noise (P < 0.05). In contrast, the subjects over 50 years of age did not exhibit a significant decrease in 3 CPM activity. Regardless of age, noise did not alter blood pressure or heart rate. CONCLUSION: GMA changes with age. Loud noise can alter GMA, especially in younger individuals. Our data indicate that even short-term exposure to noise may alter the contractility of the stomach.展开更多
AIM To investigate the differences of metoclopramide (MCP) action on myoelectric activity of antrum and small intestine. METHODS Ten healthy male Wistar rats, weighing 250g～350g, were anesthetized with ketamine hy...AIM To investigate the differences of metoclopramide (MCP) action on myoelectric activity of antrum and small intestine. METHODS Ten healthy male Wistar rats, weighing 250g～350g, were anesthetized with ketamine hydrochloride (100mg/kg, intramuscularly). Four pairs of bipolar stainless steel electrodes 3mm apart were implanted on serosal surface of antrum and 1, 10 and 20cm distal to pylorus respectively. Five to 10 days after operation, the gastrointestinal myoelectric activity of fasted rats after intramuscular injection of 2 5, 6 and 12mg/kg MCP respectively ws recorded with a 8 channel EEG machine, and was quantitatively compared with the myoelectric activity after saline injection. RESULTS In fasted rats, 2 5mg/kg MCP increased the amplitude of spike activity (402 0μV±138 4μV, vs 345 0μV±163 4μV, P <0 05) and the percentage of the slow wave containing spike bursts (60 4%±22 0% vs 47 4%±22 5%, P <0 01) of small intestine (1cm distal to pylorus), but did not affect the myoelectric activity of antrum. Six and 12mg/kg MCP increased the amplitude of both the slow wave (332 8μV±200 1μV vs 191 2μV±143 9μV, P <0 01; 330 0μV±197 1μV vs 191 2μV±143 9μV, P <0 05) and the spike activity (180 5μV±69 7μV vs 121 8μV±63 3μV, P <0 05; 174 5μV±71 7μV vs 123 8μV±63 3μV, P <0 05) of antrum, while in small intestine (1cm distal to pylorus) only that of the amplitude of spike activity (407 3μV±179 0μV vs 345 0μV±163 4μV, P <0 05; 456 0μV±145 4μV vs 345 0μV±163 4μV, P <0 05) and the percentage of the slow wave containing spike bursts (61 7%±26 5% vs 47 4%±22 5%, P <0 01; 59 1%±17 3% vs 47 4%±22 5%, P <0 01) was increased and with latent period significantly prolonged (2 5min±0 35min vs 0 77min±0 18min, P <0 01). CONCLUSION Different mechanisms may be involved in increasing the myoelectric activity of antrum and small intestine after MCP administration.展开更多
Objective To investigate the effects of peptide YY (PYY) on the interdigestive migrating myoelectric complex (MMC) in the small intestine in vivo and explore the neural and endocrinal mechanisms of the effects. Method...Objective To investigate the effects of peptide YY (PYY) on the interdigestive migrating myoelectric complex (MMC) in the small intestine in vivo and explore the neural and endocrinal mechanisms of the effects. Methods Sprague-Dawley rats were supplied with a venous catheter and bipolar electrodes in the duodenum and jejunum for electromyography of stomach and small intestine in wake state. PYY,phentolamine,nitro-L-arginine (L-NNA,the inhibitor of nitric oxide synthase) and atropine were served with PYY respectively. The plasma motilin levels before and after the infusion of PYY were observed. Results At all the three recording points,PYY lengthened the circle length of MMC [from (591.90±128.98)s to (999.25±216.59)s,P<0.01] and lowered the frequency of phase Ⅲ [from (39.28±8.40) min-1 to (22.08±3.13) min-1,P<0.01],amplitude of phase Ⅲ [from (0.320±0.060)mV to (0.179±0.030)mV,P<0.01],and the portion of phase Ⅲ over the whole circle length [from (28.61±5.84)% to (15.43±5.16)% ,P<0.01]. Phentolamine had no influence on the role of PYY. Administered L-NNA combined with PYY,the percentage of phase Ⅲ increased [(42.09±8.67)%] compared with that of control (P<0.01) and compared with that of PYY administered alone (P<0.01) too. Atropine combined with PYY showed stronger depressing effects on MMC. No significant difference was found between the plasma motilin levels before and after the infusion of PYY. Conclusion PYY may inhibit the interdigestive intestine motility through the none-adrenergic none-cholinergic tract,while the α-receptor tract and circulating motilin are probably not involved in the depressing effect.展开更多
BACKGROUND： Researches prove that the treatment of cerebral palsy by botulinus toxin （BTX-A） can improve effect and prolong effective duration. Current intensity is the important factor during injection. OBJECTIVE...BACKGROUND： Researches prove that the treatment of cerebral palsy by botulinus toxin （BTX-A） can improve effect and prolong effective duration. Current intensity is the important factor during injection. OBJECTIVE： To observe the changes of motor function and muscular intensity of children with spastic cerebral palsy after injecting BTX-A and analyze correlation between current intensity and effective duration. DESIGN： Cases control trial before and after nerves block SETTING： Capital University of Medical Sciences, China Rehabilitation Research Center PARTICIPANTS： From June 2002 to November 2004, 14 children with spastic cerebral palsy were treated by BTX-A block. All children were hospitalized in the Children Rehabilitation Department of China Rehabilitation Research Center. The children included 9 male and 5 female, and ranged from 4 to 13 years old, and average age was （6±2） years. Muscular tension ranged from grade 1 to grade 3. The diagnosis and the tape of cerebral palsy based on standard of the Fist Nationwide Cerebral Palsy Symposium, and all children were diagnosed with electroencephalogram （EEG）, CT and MRI, and permitted by their guardians. METHODS： （1） Locating and calculation： To locate block points by G6805-2A electro-therapeutic apparatus （Shanghai Huayi Electronic Instrument Plant） at the least stimulating current （continuous wave; impulse frequency; 2.667-83.333 Hz; current intensity： 0-6 mA; voltage： 6 V） to touch off muscles contraction. The current intensity of each point was recorded, and the average current intensity of each patient was calculated at the same time. （2） Dose of BTX-A： Basing upon the spastic degree and weight of patients, the dose was made certain： dose （IU）=（scores of Modified Ashworth Scale ＋2.5） xweight （kg）. The number of the block points was in all 4. The dose of injection ranged from 50 IU to 160 IU with the average of （73.6＋25.8） IU. The BTX-A was made by Lanzhou Institute of Biological Products, and each bottle contains 100 IU BTX-A. Muscular tension was evaluated by Modified Ashworth Scale. The scale ranged from grade 0 to grade 4, and the scores were from 0 to 4. The higher the scores were, the higher the muscular tension was. （3） Effect： Changes of muscular tension were evaluated by modified Ashworth Scale before and after block. Motor function was evaluated by Physician Rating Scale （PRS） before and after treatment. It contained Gait pattern, Hindfoot （ankle） position （stance-floor contact）, Hindfoot position （foot strike）, Knee position （degree of recurvation）, Crouch and Speed of gait. The scores ranged from 0 to 14. The higher the points were, the better the motor function was. （4） Effective duration： The duration was definited by the recovering of the Modified Ashworth Scale. （5） Statistic analysis： Firstly, the current intensity and the effect duration were analyzed by One-Sample Kolmogorov-Smirnov Test, the current intensity： Z= 0.456, P= 0.985, the effective duration： Z= 0.557, P= 0.915. Both data were normal distribution. Secondly, both data were analyzed by Linear Regression. The efficiency of the BTX-A block was analyzed by paired-samples t test. MAIN OUTCOME MEASURES： （1） Changes of motor function of muscular tension; （2） correlation between current intensity and effective duration. RESULTS： Fourteen children with spastic cerebral palsy were all involved in the final analysis. （1） Therapeutic effect： The average score of Ashworth scale after block was lower than that before block [（1.02±0.34） points vs. （2.12±0.48） points, t= 3.644, P〈 0.01]. The average score of RPS after block was higherthan that before block [（9.75±2.78） points vs. （6.16±0.58） points, t =13.222, P〈 0.01]. （2） Relation between the current intensity and the effective duration： The current intensity was （0.1857±0.0506） mA, and the effective duration was （26.36±4.48） weeks. The current intensity was negative correlation with effective duration （r = -0.775, P = 0.01 ）. CONCLUSION： （1） BTX-A occlusion can decrease muscular tension and improve motor function of lower limbs of children with spastic cerebral palsy. （2） The lower the current intensity is, the longer the effective duration is.展开更多
Bionic limbs require reliable,low-noise and high-comfort interfaces between electrodes and the prosthetic system.This work presents the first fully flexible,wearable myoelectric control system compatible with both dry...Bionic limbs require reliable,low-noise and high-comfort interfaces between electrodes and the prosthetic system.This work presents the first fully flexible,wearable myoelectric control system compatible with both dry and wet electrodes.It features a low-noise front-end circuit on foil using amorphous Indium-Gallium-Zinc-Oxide(a-IGZO)Thin-Film Transistors,optimized for multi-electrode sensing.The design includes an autozeroed pre-charging buffer to minimize offset and 1/f noise while maintaining high input impedance(841 MΩat 50 Hz).The front-end achieves 22µVrms input noise,<-90 dBc crosstalk,and a 4.6 mV input offset consuming 55.3µW per channel.EMG signals measured by this AFE were used to drive an elbow musculoskeletal model and predict the resulting human elbow flexion-extension moments,which in turn were used to realize a closed-loop real-time control in a simulated bionic elbow joint,using both dry and wet electrodes.Experiments done with a series of movements show a 20°rms error in angular control.展开更多
Surface electromyogram(sEMG)serves as a means to discern human movement intentions,achieved by applying epidermal electrodes to specific body regions.However,it is difficult to obtain high-fidelity sEMG recordings in ...Surface electromyogram(sEMG)serves as a means to discern human movement intentions,achieved by applying epidermal electrodes to specific body regions.However,it is difficult to obtain high-fidelity sEMG recordings in areas with intricate curved surfaces,such as the body,because regular sEMG electrodes have stiff structures.In this study,we developed myoelectrically sensitive hydrogels via 3D printing and integrated them into a stretchable,flexible,and high-density sEMG electrodes array.This electrode array offered a series of excellent human-machine interface(HMI)features,including conformal adherence to the skin,high electron-to-ion conductivity(and thus lower contact impedance),and sustained stability over extended periods.These attributes render our electrodes more conducive than commercial electrodes for long-term wearing and high-fidelity sEMG recording at complicated skin interfaces.Systematic in vivo studies were used to investigate its efficacy to control a prosthetic hand by decoding sEMG signals from the human hand via a multiple-channel readout circuit and a sophisticated artificial intelligence algorithm.Our findings demonstrate that the 3D printed gel myoelectric sensing system enables real-time and highly precise control of a prosthetic hand.展开更多
The human hand,essential for performing daily tasks and facilitating social interaction,is indispensable to everyday life.Millions worldwide experience varying levels of amputation,profoundly affecting their physical,...The human hand,essential for performing daily tasks and facilitating social interaction,is indispensable to everyday life.Millions worldwide experience varying levels of amputation,profoundly affecting their physical,emotional,and psychological well-being,limiting independence,and reducing quality of life.Myoelectric prosthetics,the most advanced active prosthetic hands,use surface electromyography(sEMG)signals and pattern recognition to translate user intentions into control signals.Despite these advancements,high rejection rates persist due to the non-stationarity of sEMG signals,leading to inconsistent and often frustrating user experiences.As a result,clinical and academic research has increasingly focused on improving myoelectric hand gesture recognition under real-world conditions to reduce rejection rates and enhance user acceptance of myoelectric prostheses.Given the vast and diverse range of methods applied in previous research,this survey aims to systematically highlight key studies and provide an overview of the field's current achievements.Furthermore,research on machine learning for myoelectric hand gesture recognition has been largely influenced by unrelated fields of computer science,such as computer vision and natural language processing.However,myoelectric hand gesture recognition presents unique challenges,particularly severe and unpredictable covariate shifts in sEMG signals,which require specialized approaches.To address these challenges,we propose a new taxonomy for categorizing machine learning models based on feature extraction methods and decision boundary strategies.Additionally,this paper highlights the need for benchmark datasets that accurately reflect real-world conditions and emphasizes the importance of re-evaluating real-time performance,particularly when using long temporal contextual windows.This study concludes with research challenges and future research directions to enhance the accuracy of myoelectric hand gesture recognition using machine learning techniques.展开更多
Abnormal gaits including pelvic obliquity gait and knee hyperextension gait are common clinical symptoms related to flat-ground fall among elder adults.This study aimed to determine the feasibility of using lower limb...Abnormal gaits including pelvic obliquity gait and knee hyperextension gait are common clinical symptoms related to flat-ground fall among elder adults.This study aimed to determine the feasibility of using lower limb myoelectrical signals(electromyographic signals,EMG)for gait pattern recognition and to identify the optimal machine learning(ML)algorithms for EMG signal processing.Seven healthy subjects were recruited with their EMG signals collected from eight muscles of the lower limbs during walking with normal and abnormal gaits.Four basic ML algorithms including support vector machine(SVM),K-nearest neighbor(kNN),decision tree(DT),and naive Bayes(NB),and five deep learning models including convolutional neural network(CNN),long-short term memory(LSTM),bidirectional long short-term memory(BiLSTM),and CNN-BiLSTM were used to process the EMG signals recorded under different gaits.Statistical analysis was performed to compare the accuracy of individual ML algorithms in discriminating gait patterns.The overall accuracy was 95.78%for SVM,95.09%for CNN-LSTM,and 96.28%for CNN-BiLSTM,respectively.The overall accuracy was 90.25%for DT,92.62%for kNN,91.27%for NB,and 90.34%for CNN,respectively.The accuracy was 67.39%for LSTM and 74.75%for BiLSTM,respectively.Most ML algorithms in this study had an accuracy greater than 90%in EMG-based abnormal gait pattern recognition except for LSTM and BiLSTM.This study provides novel technology for evaluation of gait pattern recognition related to flat ground fall.展开更多
In recent years,the functionality of myoelectric prosthetic hands has improved as motors have become smaller and controls have become more advanced.Attempts have been made to reproduce the rotation and flexion of the ...In recent years,the functionality of myoelectric prosthetic hands has improved as motors have become smaller and controls have become more advanced.Attempts have been made to reproduce the rotation and flexion of the wrist by adding degrees of freedom to the wrist joint.However,it is still difficult to fully reproduce the functionality of the wrist joint owing to the weight of the prosthesis and size limitations.In this study,we developed a new socket and prosthetic hand control system that does not interfere with the wrist joint motion.This allows individuals with hand defects who previously used prosthetic hands with fixed wrist joints to freely use their remaining wrist functionality.In the pick-and-place experiment,where blocks were moved from higher to lower locations,we confirmed that the proposed system resulted in a lower elbow position compared with the traditional prosthesis,and the number of blocks transported increased.This significantly reduced the compensatory motion of the elbow and improved the user’s performance compared with the use of a conventional prosthetic hand.This study demonstrates the usefulness of a new myoelectric prosthetic hand that utilizes the residual functions of people with hand deficiencies,which have not been utilized in the past,and the direction of its development.展开更多
Objective:To investigate the effects of different acupuncture manipulations on Deqi sensations and surface myoelectricity,and explore the correlation between Deqi sensations and needling manipulations.Methods:Forty-fi...Objective:To investigate the effects of different acupuncture manipulations on Deqi sensations and surface myoelectricity,and explore the correlation between Deqi sensations and needling manipulations.Methods:Forty-five healthy participants accepted twirling,lifting-thrusting,and twirling plus lifting-thrusting manipulanions at right Zusanli(ST 36),respectively.The acupuncturist’s and participants’Deqi sensations were collected by MGH Acupuncture Sensation Scale(MASS).The intensity and occurrence rate of soreness,dull pain,pressure,heaviness,fullness,numbness,sharp pain,warmth,coolness,and throbbing feelings of participants,and tightness,smooth,and tangle feelings of acupuncturist were measured.The correlation between the acupuncturist’s and participant’s Deqi sensations was analyzed.Surface electromyogram(EMG)was recorded before,during and after needling in 30 participants.The integrated EMG(iEMG),mean power frequency(MPF)and media frequency(MF)were analyzed.Result:Both fullness and soreness of participants and tightness of acupuncturist were the most frequently occurred ones.A positive correlation between participants’fullness and acupuncturist’s tightness was observed during the three aforementioned needling manipulations(P<0.05,OR>1).Almost all the needling sensations measured in the present study could be induced by the three needling manipulations.However,strength of Deqi sensations was exhibited as lifting-thrusting>twirling plus lifting-thrusting>twirling according to MASS index.The i EMG values were increased and MPF,MF values were decreased during needling compaired to those before needling,especially during lifting-thrusting(P<0.01).Conclusions:The intensity and occurrence rate of the different Deqi sensations induced by different needling manipulations were basically similar.The fullness and soreness were both the most frequently induced Deqi sensations.The strongest Deqi sensation could be induced by lifting-thrusting manipulation.There is a positive correlation between participants’fullness and acupuncturist’s tightness during the three needling manipulations.The myoelectricity around the acupoint is related to Deqi responses.(Registration No.AMCTR-IOR-20000314).展开更多
It is vital to recognize the intention of finger motions for human-machine interaction(HMI).The latest research focuses on fine myoelectric control through the decoding of neural motor unit action potential trains(MUA...It is vital to recognize the intention of finger motions for human-machine interaction(HMI).The latest research focuses on fine myoelectric control through the decoding of neural motor unit action potential trains(MUAPt) from high-density surface electromyographic(sEMG) signals.However,the existing EMG decoding algorithms rarely obtain the spatial matching relationship between decoded motion units(MU) and designated muscles,and the control interface can only recognize the trained hand gestures.In this study,a semi-supervised HMI based on MU-muscle matching(MMM) is proposed to recognize individual finger motions and even the untrained combined multi-finger actions.Through automatic channel selection from high-density s EMG signals,the optimal spatial positions to monitor the MU activation of finger muscles are determined.Finger tapping experiment is carried out on ten subjects,and the experimental results show that the proposed s EMG decomposition algorithm based on MMM can accurately identify single finger motions with an accuracy of 93.1%±1.4%,which is comparable to that of state-of-the-art pattern recognition methods.Furthermore,the MMM allows unsupervised recognizing the untrained combined multi-finger motions with an accuracy of 73%±3.8%.The outcomes of this study benefit the practical applications of HMI,such as controlling prosthetic hand and virtual keyboard.展开更多
Myoelectric controlled interfaces driven by muscle activities have achieved good performance in ideal conditions and showed many potential medical-related and industrial applications.However,in practical applications,...Myoelectric controlled interfaces driven by muscle activities have achieved good performance in ideal conditions and showed many potential medical-related and industrial applications.However,in practical applications,the performance could be drastically degraded due to the electrode(sensor)shift,which is inevitable in donning and doffing the system.In this study,we presented a novel channel selection method against electrode shift for robust pattern-recognition based myoelectric control.The proposed method was evaluated on twenty-four subjects,including twenty-two able-bodied subjects and two amputees,and compared with two traditional channel selection methods,i.e.,uniform selection(UNI)and sequential feature selection(SFS).We demonstrated that the offline error rates of the proposed method were significantly lower than those of the other two methods(P<0.05),and its online performance in shift conditions was comparable to that in ideal conditions.These outcomes benefit the practical applications of robust myoelectric controlled interfaces.展开更多
Currently, prosthetic hands can only achieve several prespecified and discrete hand motion patterns from popular myoelectric control schemes using electromyography(EMG) signals. To achieve continuous and stable graspi...Currently, prosthetic hands can only achieve several prespecified and discrete hand motion patterns from popular myoelectric control schemes using electromyography(EMG) signals. To achieve continuous and stable grasping within the discrete motion pattern, this paper proposes a control strategy using a customized, flexible capacitance-based proximity-tactile sensor. This sensor is integrated at the fingertip and measures the distance and force before and after contact with an object. During the pregrasping phase, each fingertip’s position is controlled based on the distance between the fingertip and the object to make all fingertips synchronously approach the object at the same distance. Once contact is established, the sensor turns to output the tactile information, by which the contact force of each fingertip is finely controlled. Finally, the method is introduced into the human-machine interaction control for a myoelectric prosthetic hand. The experimental results demonstrate that continuous and stable grasping could be achieved by the proposed control method within the subject’s discrete EMG motion mode. The subject also obtained tactile feedback through the transcutaneous electrical nerve stimulation after contact.展开更多
AIM: To investigate the mechanisms and effects of sphincter of Oddi(SO) motility on cholesterol gallbladder stone formation in guinea pigs.METHODS: Thirty-four adult male Hartley guinea pigs were divided randomly into...AIM: To investigate the mechanisms and effects of sphincter of Oddi(SO) motility on cholesterol gallbladder stone formation in guinea pigs.METHODS: Thirty-four adult male Hartley guinea pigs were divided randomly into two groups, the control group(n = 10) and the cholesterol gallstone group(n = 24), which was sequentially divided into four subgroups with six guinea pigs each according to time of sacrifice. The guinea pigs in the cholesterol gallstone group were fed a cholesterol lithogenic diet and sacrificed after 3, 6, 9, and 12 wk. SO manometry and recording of myoelectric activity were obtained by a multifunctional physiograph at each stage. Cholecystokinin-A receptor(CCKAR) expression levels in SO smooth muscle were detected by quantitative real-time PCR(q RT-PCR) and serum vasoactive intestinal peptide(VIP), gastrin, and cholecystokinin octapeptide(CCK-8) were detected by enzyme-linked immunosorbent assay at each stage in the process of cholesterol gallstone formation.RESULTS: The gallstone formation rate was 0%, 0%, 16.7%, and 83.3% in the 3, 6, 9, and 12 wk groups, respectively. The frequency of myoelectric activity in the 9 wk group, the amplitude of myoelectric activity in the 9 and 12 wk groups, and the amplitude and the frequency of SO in the 9 wk group were all significantly decreased compared to the control group. The SO basal pressure and common bile duct pressure increased markedly in the 12 wk group, and the CCKAR expression levels increased in the 6 and 12 wk groups compared to the control group. Serum VIP was elevated significantly in the 9 and 12 wk groups and gastrin decreased significantly in the 3 and 9 wk groups. There was no difference in serum CCK-8 between the groups.CONCLUSION: A cholesterol gallstone-causing diet can induce SO dysfunction. The increasing tension of the SO along with its decreasing activity may play an important role in cholesterol gallstone formation. Expression changes of CCKAR in SO smooth muscle and serum VIP and CCK-8 may be important causes of SO dysfunction.展开更多
基金the National Natural Science Foundation of China,No.60876082,81070779the grant from Shanghai Committee of Science and Technology,No.0852nm06600the "Shu Guang" Project supported by Shanghai Municipal Educa-tion Commission and Shanghai Education Devel-opment Foundation,No.08SG13
文摘Artificial facial nerve prostheses are thought to restore eye-closed function in peripheral facial paralysis patients.At present,however,there is no adequate quantitative or qualitative information regarding myoelectric signal（MES）features for healthy orbiculads oculi muscle（OOM）.The present study analyzed MES features of normal OOM in rabbits during the natural continuous eye-opening（N1）state,natural continuous eye-closing（N2）state,natural blink（N3）state,and evoked eye-closing（E）state according to time domain and frequency domain analysis.Results showed that OOM electrical activities in N1 and N2 states,as well as myoelectric amplitude,were low and stable.Nevertheless,during N3 and E states,OOM electrical activities were significantly increased and amplitude was much higher in the E state than in the N3 state.In the time domain,differences in MES peak absolute potential were not significant between N1 and N2 states,in the frequency domain,differences in power spectral density peak frequency of electromyogram signals were significant between two sets of four OOM movement states.These results suggest that OOM significantly contracts and induces eyelid-closing action.In addition,OOM is diastolic during the N1state.A N2 state does not require continuous intensive OOM contraction.Moreover,distinctions of quantitative information in time and frequency domain features of MES can be used as an OOM reference to identify muscle movement patterns.
基金Supported by the National Key Program (973) of China Project on Basis and Theories of Traditional Chinese Medicine No. 2005-CB523305
文摘AIM： To explore the mechanism of the exciting effects of electro-acupuncture （EA） at Sibai on the gastric myoelectric activities. METHODS： A total of 32 rats were randomly divided into four groups. Through intraperitoneal injection with atropine （the anti-cholinergic agent by blockade of muscarinic receptors）, hexarnethonium （automatic nerve ganglion-blocking agent） and reserpine （anti-adrenergic agent by depleting the adrenergic nerve terminal of its norepinephrine store）, effects of EA at Sibai on the gastric myoelectric activities of the denervated rats were observed. RESULTS： After intraperitoneal injection of atropine and hexamethonium, the average amplitude and ratio of period to time in the phase of high activity of gastric myoelectric slow wave, and the average numbers of the peaks of gastric myoelectric fast wave were significantly decreased （P 〈 0.01, P 〈 0.05, P 〈 0.01）, while after intraperitoneal injection of reserpine, the aforementioned three parameters were increased （P 〈 0.01, P 〈 0.05, P 〈 0.01）. EA at Sibai point partially relieved the inhibitory effect of atropine and hexamethonium on the gastric myoelectric activities in the rats （P 〈 0.05 or P 〉 0.05）. CONCLUSION： Cholinergic and adrenergic nervous systems and autonomic nerve ganglion participate in the peripheral passage of the controlling effects of EA at Foot Yangming Channel on gastrointestinal tract.
基金Supported by National Natural Science Foundation of China, No. 30170414
文摘AIM： To investigate the effects of entero-hepatic bile add circulation on the inter-digestive migrating myoelectrical complex （MMC） in rats. METHODS： Thirty-two rats were divided into four groups. Three pairs of bipolar silver electrodes were chronically implanted in the antrum, duodenum and jejunum. Three groups of Uhem were ligatecl around the upper part of common bile duct （CBD）. The experiments were performed in consdous and fasting state. The gastrointestinal myoelectrical activity was recorded. Ursodeoxycholic acid （UDCA） and saline were then perfused into stomachs of two groups with CBD obstruction and the effects of them on the MMC were observed. RESULTS： A typical pattern of MMC was observed in normal fasting rats. MMC of antral and duodenal origin disappeared temporarily in earlier stage of CBD obstruction. While MMC of jejunum origin appeared. increased MMC cycle duration was seen after 4 d in rats with CBD obstruction. The MMC after CBD obstruction was characterized by an increased duration of phase Ⅱ-like activity and decreased duration of phase Ⅰ ＆ Ⅲ activity. Perfusion into stomachs with UDCA resulted in a shorter MMC cycle duration and a longer duration of phase III of duodenal origin compared to the normal group. CONCLUSION： Entero-hepatic bile add drculation initiates inter-digestive MMC of duodenal origin.
基金The Clinical Speciality Emphasis Topic Foundation of Department of Health(No.2004-56)
文摘Objective:To investigate the distribution of the motilin receptor in the amygdala of rats and its role in regulating the duodenal migrating myoelectric complex(MMC).Methods:The distribution of motilin receptor in the amygdala in adult SD rats was detected by immunohistochemistry methods,and the duodenal interdigestive MMC was recorded via the electrodes implanted in the duodenum and analyzed us- ing a multichannel recorder.Results:Motilin receptor was observed in the amygdala of rats.The great amount of motilin receptor was found in the medial amygdaloid nucleus,which was also abundant in the basolateral nucleus but less abundant in the basomedial amygdaloid nucleus,the central amygdaloid nucle- us and the lateral amygdaloid nucleus.The shortening of the duodenal MMC cycle duration and the in- crease of the amplitude and the frequency of phase $ were recorded after motilin receptors being bound with exogenous motilin in the amygdala.The effects could be completely blocked by the subdiaphragmatic vagotomy but not by the intravenous injections of atropine,phentolamine or propranolol.Anti-motilin serum could partially block these effects,and the destruction of the basolateral nucleus of the amygdala had no significant effects on the duodenal MMC.Conclusion:Motilin receptor is present in all the subnu- clei of the amygdala,with the greatest amount of motilin receptor present in the medial amygdaloid nucle- us.Microinjections of motilin in the amygdala can shorten the duodenal MMC cycle duration and increase the amplitude and the frequency of phaseⅢ.These effects might be accomplished via the amygdala-hy- pothalamus-brainstem-vagus pathway,indicating the important role of the amygdala motilin receptor in the duodenal MMC regulation.
文摘AIM: To evaluate the effect of age and acoustic stress on gastric myoelectrical activity (GMA) and autonomic nervous system function. METHODS: Twenty-one male subjects (age range 22-71 years, mean 44 years) were recruited and exposed, in random order, to three auditory stimuli (Hospital noise, conversation babble and traffic noise) after a 20-min baseline. All periods lasted 20 min and were interspersed with a 10 min of recovery. GMA was obtained using a Synectics Microdigitrapper. Autonomic nerve function was assessed by monitoring blood pressure and heart rate using an automatic recording device. RESULTS: Dominant power tended to decrease with increase of age (P < 0.05). The overall percentage of three cycle per minute (CPM) activity decreased during exposure to hospital noise (12.0%, P < 0.05), traffic noise (13.9%, P < 0.05), and conversation babble (7.1%). The subjects in the younger group (< 50 years) showed a consistent reduction in the percentage of 3 CPM activity during hospital noise (22.9%, P < 0.05), traffic noise (19.0%, P < 0.05), and conversation babble (15.5%). These observations were accompanied by a significant increase in bradygastria: hospital noise (P < 0.05) and traffic noise (P < 0.05). In contrast, the subjects over 50 years of age did not exhibit a significant decrease in 3 CPM activity. Regardless of age, noise did not alter blood pressure or heart rate. CONCLUSION: GMA changes with age. Loud noise can alter GMA, especially in younger individuals. Our data indicate that even short-term exposure to noise may alter the contractility of the stomach.
文摘AIM To investigate the differences of metoclopramide (MCP) action on myoelectric activity of antrum and small intestine. METHODS Ten healthy male Wistar rats, weighing 250g～350g, were anesthetized with ketamine hydrochloride (100mg/kg, intramuscularly). Four pairs of bipolar stainless steel electrodes 3mm apart were implanted on serosal surface of antrum and 1, 10 and 20cm distal to pylorus respectively. Five to 10 days after operation, the gastrointestinal myoelectric activity of fasted rats after intramuscular injection of 2 5, 6 and 12mg/kg MCP respectively ws recorded with a 8 channel EEG machine, and was quantitatively compared with the myoelectric activity after saline injection. RESULTS In fasted rats, 2 5mg/kg MCP increased the amplitude of spike activity (402 0μV±138 4μV, vs 345 0μV±163 4μV, P <0 05) and the percentage of the slow wave containing spike bursts (60 4%±22 0% vs 47 4%±22 5%, P <0 01) of small intestine (1cm distal to pylorus), but did not affect the myoelectric activity of antrum. Six and 12mg/kg MCP increased the amplitude of both the slow wave (332 8μV±200 1μV vs 191 2μV±143 9μV, P <0 01; 330 0μV±197 1μV vs 191 2μV±143 9μV, P <0 05) and the spike activity (180 5μV±69 7μV vs 121 8μV±63 3μV, P <0 05; 174 5μV±71 7μV vs 123 8μV±63 3μV, P <0 05) of antrum, while in small intestine (1cm distal to pylorus) only that of the amplitude of spike activity (407 3μV±179 0μV vs 345 0μV±163 4μV, P <0 05; 456 0μV±145 4μV vs 345 0μV±163 4μV, P <0 05) and the percentage of the slow wave containing spike bursts (61 7%±26 5% vs 47 4%±22 5%, P <0 01; 59 1%±17 3% vs 47 4%±22 5%, P <0 01) was increased and with latent period significantly prolonged (2 5min±0 35min vs 0 77min±0 18min, P <0 01). CONCLUSION Different mechanisms may be involved in increasing the myoelectric activity of antrum and small intestine after MCP administration.
基金supported by the National Natural Science Foundation of China (No.30170414)
文摘Objective To investigate the effects of peptide YY (PYY) on the interdigestive migrating myoelectric complex (MMC) in the small intestine in vivo and explore the neural and endocrinal mechanisms of the effects. Methods Sprague-Dawley rats were supplied with a venous catheter and bipolar electrodes in the duodenum and jejunum for electromyography of stomach and small intestine in wake state. PYY,phentolamine,nitro-L-arginine (L-NNA,the inhibitor of nitric oxide synthase) and atropine were served with PYY respectively. The plasma motilin levels before and after the infusion of PYY were observed. Results At all the three recording points,PYY lengthened the circle length of MMC [from (591.90±128.98)s to (999.25±216.59)s,P<0.01] and lowered the frequency of phase Ⅲ [from (39.28±8.40) min-1 to (22.08±3.13) min-1,P<0.01],amplitude of phase Ⅲ [from (0.320±0.060)mV to (0.179±0.030)mV,P<0.01],and the portion of phase Ⅲ over the whole circle length [from (28.61±5.84)% to (15.43±5.16)% ,P<0.01]. Phentolamine had no influence on the role of PYY. Administered L-NNA combined with PYY,the percentage of phase Ⅲ increased [(42.09±8.67)%] compared with that of control (P<0.01) and compared with that of PYY administered alone (P<0.01) too. Atropine combined with PYY showed stronger depressing effects on MMC. No significant difference was found between the plasma motilin levels before and after the infusion of PYY. Conclusion PYY may inhibit the interdigestive intestine motility through the none-adrenergic none-cholinergic tract,while the α-receptor tract and circulating motilin are probably not involved in the depressing effect.
文摘BACKGROUND： Researches prove that the treatment of cerebral palsy by botulinus toxin （BTX-A） can improve effect and prolong effective duration. Current intensity is the important factor during injection. OBJECTIVE： To observe the changes of motor function and muscular intensity of children with spastic cerebral palsy after injecting BTX-A and analyze correlation between current intensity and effective duration. DESIGN： Cases control trial before and after nerves block SETTING： Capital University of Medical Sciences, China Rehabilitation Research Center PARTICIPANTS： From June 2002 to November 2004, 14 children with spastic cerebral palsy were treated by BTX-A block. All children were hospitalized in the Children Rehabilitation Department of China Rehabilitation Research Center. The children included 9 male and 5 female, and ranged from 4 to 13 years old, and average age was （6±2） years. Muscular tension ranged from grade 1 to grade 3. The diagnosis and the tape of cerebral palsy based on standard of the Fist Nationwide Cerebral Palsy Symposium, and all children were diagnosed with electroencephalogram （EEG）, CT and MRI, and permitted by their guardians. METHODS： （1） Locating and calculation： To locate block points by G6805-2A electro-therapeutic apparatus （Shanghai Huayi Electronic Instrument Plant） at the least stimulating current （continuous wave; impulse frequency; 2.667-83.333 Hz; current intensity： 0-6 mA; voltage： 6 V） to touch off muscles contraction. The current intensity of each point was recorded, and the average current intensity of each patient was calculated at the same time. （2） Dose of BTX-A： Basing upon the spastic degree and weight of patients, the dose was made certain： dose （IU）=（scores of Modified Ashworth Scale ＋2.5） xweight （kg）. The number of the block points was in all 4. The dose of injection ranged from 50 IU to 160 IU with the average of （73.6＋25.8） IU. The BTX-A was made by Lanzhou Institute of Biological Products, and each bottle contains 100 IU BTX-A. Muscular tension was evaluated by Modified Ashworth Scale. The scale ranged from grade 0 to grade 4, and the scores were from 0 to 4. The higher the scores were, the higher the muscular tension was. （3） Effect： Changes of muscular tension were evaluated by modified Ashworth Scale before and after block. Motor function was evaluated by Physician Rating Scale （PRS） before and after treatment. It contained Gait pattern, Hindfoot （ankle） position （stance-floor contact）, Hindfoot position （foot strike）, Knee position （degree of recurvation）, Crouch and Speed of gait. The scores ranged from 0 to 14. The higher the points were, the better the motor function was. （4） Effective duration： The duration was definited by the recovering of the Modified Ashworth Scale. （5） Statistic analysis： Firstly, the current intensity and the effect duration were analyzed by One-Sample Kolmogorov-Smirnov Test, the current intensity： Z= 0.456, P= 0.985, the effective duration： Z= 0.557, P= 0.915. Both data were normal distribution. Secondly, both data were analyzed by Linear Regression. The efficiency of the BTX-A block was analyzed by paired-samples t test. MAIN OUTCOME MEASURES： （1） Changes of motor function of muscular tension; （2） correlation between current intensity and effective duration. RESULTS： Fourteen children with spastic cerebral palsy were all involved in the final analysis. （1） Therapeutic effect： The average score of Ashworth scale after block was lower than that before block [（1.02±0.34） points vs. （2.12±0.48） points, t= 3.644, P〈 0.01]. The average score of RPS after block was higherthan that before block [（9.75±2.78） points vs. （6.16±0.58） points, t =13.222, P〈 0.01]. （2） Relation between the current intensity and the effective duration： The current intensity was （0.1857±0.0506） mA, and the effective duration was （26.36±4.48） weeks. The current intensity was negative correlation with effective duration （r = -0.775, P = 0.01 ）. CONCLUSION： （1） BTX-A occlusion can decrease muscular tension and improve motor function of lower limbs of children with spastic cerebral palsy. （2） The lower the current intensity is, the longer the effective duration is.
基金project Smart-Sense(with project number17608)which is(partly)financed by the Dutch Research Council(NWO)。
文摘Bionic limbs require reliable,low-noise and high-comfort interfaces between electrodes and the prosthetic system.This work presents the first fully flexible,wearable myoelectric control system compatible with both dry and wet electrodes.It features a low-noise front-end circuit on foil using amorphous Indium-Gallium-Zinc-Oxide(a-IGZO)Thin-Film Transistors,optimized for multi-electrode sensing.The design includes an autozeroed pre-charging buffer to minimize offset and 1/f noise while maintaining high input impedance(841 MΩat 50 Hz).The front-end achieves 22µVrms input noise,<-90 dBc crosstalk,and a 4.6 mV input offset consuming 55.3µW per channel.EMG signals measured by this AFE were used to drive an elbow musculoskeletal model and predict the resulting human elbow flexion-extension moments,which in turn were used to realize a closed-loop real-time control in a simulated bionic elbow joint,using both dry and wet electrodes.Experiments done with a series of movements show a 20°rms error in angular control.
基金supported by the National Natural Science Foundation of China(grant numbers 42177440 and 52075177)the National Key Research and Development Program of China(Grant No.2021YFB3301400).
文摘Surface electromyogram(sEMG)serves as a means to discern human movement intentions,achieved by applying epidermal electrodes to specific body regions.However,it is difficult to obtain high-fidelity sEMG recordings in areas with intricate curved surfaces,such as the body,because regular sEMG electrodes have stiff structures.In this study,we developed myoelectrically sensitive hydrogels via 3D printing and integrated them into a stretchable,flexible,and high-density sEMG electrodes array.This electrode array offered a series of excellent human-machine interface(HMI)features,including conformal adherence to the skin,high electron-to-ion conductivity(and thus lower contact impedance),and sustained stability over extended periods.These attributes render our electrodes more conducive than commercial electrodes for long-term wearing and high-fidelity sEMG recording at complicated skin interfaces.Systematic in vivo studies were used to investigate its efficacy to control a prosthetic hand by decoding sEMG signals from the human hand via a multiple-channel readout circuit and a sophisticated artificial intelligence algorithm.Our findings demonstrate that the 3D printed gel myoelectric sensing system enables real-time and highly precise control of a prosthetic hand.
基金supported by the ARC Centre of Excellence for Electromaterials Science(CE140100012)the ARC-Discovery Project(DP210102911)the University of Wollongong.
文摘The human hand,essential for performing daily tasks and facilitating social interaction,is indispensable to everyday life.Millions worldwide experience varying levels of amputation,profoundly affecting their physical,emotional,and psychological well-being,limiting independence,and reducing quality of life.Myoelectric prosthetics,the most advanced active prosthetic hands,use surface electromyography(sEMG)signals and pattern recognition to translate user intentions into control signals.Despite these advancements,high rejection rates persist due to the non-stationarity of sEMG signals,leading to inconsistent and often frustrating user experiences.As a result,clinical and academic research has increasingly focused on improving myoelectric hand gesture recognition under real-world conditions to reduce rejection rates and enhance user acceptance of myoelectric prostheses.Given the vast and diverse range of methods applied in previous research,this survey aims to systematically highlight key studies and provide an overview of the field's current achievements.Furthermore,research on machine learning for myoelectric hand gesture recognition has been largely influenced by unrelated fields of computer science,such as computer vision and natural language processing.However,myoelectric hand gesture recognition presents unique challenges,particularly severe and unpredictable covariate shifts in sEMG signals,which require specialized approaches.To address these challenges,we propose a new taxonomy for categorizing machine learning models based on feature extraction methods and decision boundary strategies.Additionally,this paper highlights the need for benchmark datasets that accurately reflect real-world conditions and emphasizes the importance of re-evaluating real-time performance,particularly when using long temporal contextual windows.This study concludes with research challenges and future research directions to enhance the accuracy of myoelectric hand gesture recognition using machine learning techniques.
基金supported by National Natural Science Foundation of China(52035007)the Cross Fund for Medical and Engineering of Shanghai Jiao Tong University(YG2021QN118)+1 种基金Rehabilitation Institute of Michigan Foundation(Grant#22-2-003)Hubei Provincial Research Fund(023DJC019).
文摘Abnormal gaits including pelvic obliquity gait and knee hyperextension gait are common clinical symptoms related to flat-ground fall among elder adults.This study aimed to determine the feasibility of using lower limb myoelectrical signals(electromyographic signals,EMG)for gait pattern recognition and to identify the optimal machine learning(ML)algorithms for EMG signal processing.Seven healthy subjects were recruited with their EMG signals collected from eight muscles of the lower limbs during walking with normal and abnormal gaits.Four basic ML algorithms including support vector machine(SVM),K-nearest neighbor(kNN),decision tree(DT),and naive Bayes(NB),and five deep learning models including convolutional neural network(CNN),long-short term memory(LSTM),bidirectional long short-term memory(BiLSTM),and CNN-BiLSTM were used to process the EMG signals recorded under different gaits.Statistical analysis was performed to compare the accuracy of individual ML algorithms in discriminating gait patterns.The overall accuracy was 95.78%for SVM,95.09%for CNN-LSTM,and 96.28%for CNN-BiLSTM,respectively.The overall accuracy was 90.25%for DT,92.62%for kNN,91.27%for NB,and 90.34%for CNN,respectively.The accuracy was 67.39%for LSTM and 74.75%for BiLSTM,respectively.Most ML algorithms in this study had an accuracy greater than 90%in EMG-based abnormal gait pattern recognition except for LSTM and BiLSTM.This study provides novel technology for evaluation of gait pattern recognition related to flat ground fall.
基金supported by JSPS KAKENHI(grant numbers JP18H03761,JP21K14125,and JP23H00166)the New Energy and Industrial Technology Development Organization(NEDO)the Ministry of Health,Labor and Welfare(MHLW)in Japan.
文摘In recent years,the functionality of myoelectric prosthetic hands has improved as motors have become smaller and controls have become more advanced.Attempts have been made to reproduce the rotation and flexion of the wrist by adding degrees of freedom to the wrist joint.However,it is still difficult to fully reproduce the functionality of the wrist joint owing to the weight of the prosthesis and size limitations.In this study,we developed a new socket and prosthetic hand control system that does not interfere with the wrist joint motion.This allows individuals with hand defects who previously used prosthetic hands with fixed wrist joints to freely use their remaining wrist functionality.In the pick-and-place experiment,where blocks were moved from higher to lower locations,we confirmed that the proposed system resulted in a lower elbow position compared with the traditional prosthesis,and the number of blocks transported increased.This significantly reduced the compensatory motion of the elbow and improved the user’s performance compared with the use of a conventional prosthetic hand.This study demonstrates the usefulness of a new myoelectric prosthetic hand that utilizes the residual functions of people with hand deficiencies,which have not been utilized in the past,and the direction of its development.
基金Supported by the National Natural Science Foundation of China(No.81973758)China Academy of Chinese Medical Sciences Foundation(Nos.ZZ11-048,ZZ-ZR2017004,and ZZ08010)。
文摘Objective:To investigate the effects of different acupuncture manipulations on Deqi sensations and surface myoelectricity,and explore the correlation between Deqi sensations and needling manipulations.Methods:Forty-five healthy participants accepted twirling,lifting-thrusting,and twirling plus lifting-thrusting manipulanions at right Zusanli(ST 36),respectively.The acupuncturist’s and participants’Deqi sensations were collected by MGH Acupuncture Sensation Scale(MASS).The intensity and occurrence rate of soreness,dull pain,pressure,heaviness,fullness,numbness,sharp pain,warmth,coolness,and throbbing feelings of participants,and tightness,smooth,and tangle feelings of acupuncturist were measured.The correlation between the acupuncturist’s and participant’s Deqi sensations was analyzed.Surface electromyogram(EMG)was recorded before,during and after needling in 30 participants.The integrated EMG(iEMG),mean power frequency(MPF)and media frequency(MF)were analyzed.Result:Both fullness and soreness of participants and tightness of acupuncturist were the most frequently occurred ones.A positive correlation between participants’fullness and acupuncturist’s tightness was observed during the three aforementioned needling manipulations(P<0.05,OR>1).Almost all the needling sensations measured in the present study could be induced by the three needling manipulations.However,strength of Deqi sensations was exhibited as lifting-thrusting>twirling plus lifting-thrusting>twirling according to MASS index.The i EMG values were increased and MPF,MF values were decreased during needling compaired to those before needling,especially during lifting-thrusting(P<0.01).Conclusions:The intensity and occurrence rate of the different Deqi sensations induced by different needling manipulations were basically similar.The fullness and soreness were both the most frequently induced Deqi sensations.The strongest Deqi sensation could be induced by lifting-thrusting manipulation.There is a positive correlation between participants’fullness and acupuncturist’s tightness during the three needling manipulations.The myoelectricity around the acupoint is related to Deqi responses.(Registration No.AMCTR-IOR-20000314).
基金supported in part by the China National Key R&D Program(Grant No.2018YFB1307200)the National Natural Science Foundation of China (Grant Nos.51905339&91948302)。
文摘It is vital to recognize the intention of finger motions for human-machine interaction(HMI).The latest research focuses on fine myoelectric control through the decoding of neural motor unit action potential trains(MUAPt) from high-density surface electromyographic(sEMG) signals.However,the existing EMG decoding algorithms rarely obtain the spatial matching relationship between decoded motion units(MU) and designated muscles,and the control interface can only recognize the trained hand gestures.In this study,a semi-supervised HMI based on MU-muscle matching(MMM) is proposed to recognize individual finger motions and even the untrained combined multi-finger actions.Through automatic channel selection from high-density s EMG signals,the optimal spatial positions to monitor the MU activation of finger muscles are determined.Finger tapping experiment is carried out on ten subjects,and the experimental results show that the proposed s EMG decomposition algorithm based on MMM can accurately identify single finger motions with an accuracy of 93.1%±1.4%,which is comparable to that of state-of-the-art pattern recognition methods.Furthermore,the MMM allows unsupervised recognizing the untrained combined multi-finger motions with an accuracy of 73%±3.8%.The outcomes of this study benefit the practical applications of HMI,such as controlling prosthetic hand and virtual keyboard.
基金supported by the China National Key R&D Program(Grant No.2018YFB1307200)the National Natural Science Foundation of China(Grant Nos.91948302,51620105002)the Science and Technology Commission of Shanghai Municipality(Grant No.18JC1410400)。
文摘Myoelectric controlled interfaces driven by muscle activities have achieved good performance in ideal conditions and showed many potential medical-related and industrial applications.However,in practical applications,the performance could be drastically degraded due to the electrode(sensor)shift,which is inevitable in donning and doffing the system.In this study,we presented a novel channel selection method against electrode shift for robust pattern-recognition based myoelectric control.The proposed method was evaluated on twenty-four subjects,including twenty-two able-bodied subjects and two amputees,and compared with two traditional channel selection methods,i.e.,uniform selection(UNI)and sequential feature selection(SFS).We demonstrated that the offline error rates of the proposed method were significantly lower than those of the other two methods(P<0.05),and its online performance in shift conditions was comparable to that in ideal conditions.These outcomes benefit the practical applications of robust myoelectric controlled interfaces.
基金supported by the National Key R&D Program of China(Grant No. 2018YFB1307201)the National Natural Science Foundation of China (Grant Nos. U1813209 and 51875120)。
文摘Currently, prosthetic hands can only achieve several prespecified and discrete hand motion patterns from popular myoelectric control schemes using electromyography(EMG) signals. To achieve continuous and stable grasping within the discrete motion pattern, this paper proposes a control strategy using a customized, flexible capacitance-based proximity-tactile sensor. This sensor is integrated at the fingertip and measures the distance and force before and after contact with an object. During the pregrasping phase, each fingertip’s position is controlled based on the distance between the fingertip and the object to make all fingertips synchronously approach the object at the same distance. Once contact is established, the sensor turns to output the tactile information, by which the contact force of each fingertip is finely controlled. Finally, the method is introduced into the human-machine interaction control for a myoelectric prosthetic hand. The experimental results demonstrate that continuous and stable grasping could be achieved by the proposed control method within the subject’s discrete EMG motion mode. The subject also obtained tactile feedback through the transcutaneous electrical nerve stimulation after contact.
基金Supported by Natural Science Foundation of Shandong Province,China,No.ZR 2012 HM-079
文摘AIM: To investigate the mechanisms and effects of sphincter of Oddi(SO) motility on cholesterol gallbladder stone formation in guinea pigs.METHODS: Thirty-four adult male Hartley guinea pigs were divided randomly into two groups, the control group(n = 10) and the cholesterol gallstone group(n = 24), which was sequentially divided into four subgroups with six guinea pigs each according to time of sacrifice. The guinea pigs in the cholesterol gallstone group were fed a cholesterol lithogenic diet and sacrificed after 3, 6, 9, and 12 wk. SO manometry and recording of myoelectric activity were obtained by a multifunctional physiograph at each stage. Cholecystokinin-A receptor(CCKAR) expression levels in SO smooth muscle were detected by quantitative real-time PCR(q RT-PCR) and serum vasoactive intestinal peptide(VIP), gastrin, and cholecystokinin octapeptide(CCK-8) were detected by enzyme-linked immunosorbent assay at each stage in the process of cholesterol gallstone formation.RESULTS: The gallstone formation rate was 0%, 0%, 16.7%, and 83.3% in the 3, 6, 9, and 12 wk groups, respectively. The frequency of myoelectric activity in the 9 wk group, the amplitude of myoelectric activity in the 9 and 12 wk groups, and the amplitude and the frequency of SO in the 9 wk group were all significantly decreased compared to the control group. The SO basal pressure and common bile duct pressure increased markedly in the 12 wk group, and the CCKAR expression levels increased in the 6 and 12 wk groups compared to the control group. Serum VIP was elevated significantly in the 9 and 12 wk groups and gastrin decreased significantly in the 3 and 9 wk groups. There was no difference in serum CCK-8 between the groups.CONCLUSION: A cholesterol gallstone-causing diet can induce SO dysfunction. The increasing tension of the SO along with its decreasing activity may play an important role in cholesterol gallstone formation. Expression changes of CCKAR in SO smooth muscle and serum VIP and CCK-8 may be important causes of SO dysfunction.
