OBJECTIVE: To determine the effect of the area postrema (AP) of the medulla oblongata on gastrointestinal interdigestive migrating motor complex (MMC) and the plasma motilin level. METHODS: Interdigestive MMC activiti...OBJECTIVE: To determine the effect of the area postrema (AP) of the medulla oblongata on gastrointestinal interdigestive migrating motor complex (MMC) and the plasma motilin level. METHODS: Interdigestive MMC activities of the antrum and duodenum were recorded by strain gauge implanted on the serosa of 8 conscious dogs. A cannula was intubated in femoral vein for motilin injection. The plasma motilin concentration was measured by RIA. We observed: (1) normal interdigestive MMC activity and fluctuations in plasma motilin concentration; (2) the effects of electrically damaging the AP on MMC activity and plasma motilin level; (3) whether intravenous injection of motilin could induce phase III contractions after the AP was destroyed. RESULTS: (1) Typical interdigestive MMC with phase I, II, III, and IV was recorded in normal dogs. Phase III was concurrent with the peak of plasma motilin level. (2) In damaged AP dogs, antroduodenal interdigestive MMC contractions were suppressed; cyclic, phasic and migratory pattern of MMC was disrupted. Plasma motilin concentration was decreased. Intravenous injection of motilin could not induce phase III contractions. CONCLUSIONS: The area postrema might play an important role, which is mediated by motilin, on the regulation of interdigestive MMC.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
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
This paper presents an anthropomorphic prosthetic hand using flexure hinges, which is controlled by the surface electromyography （sEMG） signals from 2 electrodes only. The prosthetic hand has compact structure with ...This paper presents an anthropomorphic prosthetic hand using flexure hinges, which is controlled by the surface electromyography （sEMG） signals from 2 electrodes only. The prosthetic hand has compact structure with 5 fingers and 4 Degree of Freedoms （DoFs） driven by 4 independent actuators. Helical springs are used as elastic joints and the joints of each finger are coupled by tendons. The myoelectric control system which can classify 8 prehensile hand gestures is built. Pattern recognition is employed where Mean Absolute Value （MAV）, Variance （VAR）, the fourth-order Autoregressive （AR） coefficient and Sample Entropy （SE） are chosen as the optimal feature set and Linear Discriminant Analysis （LDA） is utilized to reduce the dimension. A decision of hand gestures is generated by LDA classifier after the current projected feature set and the previous one are ＂pre-smoothed＂, and then the final decision is obtained when the current decision and previous decisions are ＂post-smoothed＂ from the decisions flow. The prosthetic hand can perform prehensile postures for activities of daily living and carry objects under the control of EMG signals.展开更多
Hand gesture recognition(HGR)plays a vital role in human-computer interaction.The integration of high-density surface electromyography(HD-sEMG)and deep neural networks(DNNs)has significantly improved the robustness an...Hand gesture recognition(HGR)plays a vital role in human-computer interaction.The integration of high-density surface electromyography(HD-sEMG)and deep neural networks(DNNs)has significantly improved the robustness and accuracy of HGR systems.These methods are typically effective for a fixed set of trained gestures.However,the need for new gesture classes over time poses a challenge.Introducing new classes to DNNs can lead to a substantial decrease in accuracy for previously learned tasks,a phenomenon known as“catastrophic forgetting,”especially when the training data for earlier tasks is not retained and retrained.This issue is exacerbated in embedded devices with limited storage,which struggle to store the large-scale data of HD-sEMG.Classincremental learning(CIL)is an effective method to reduce catastrophic forgetting.However,existing CIL methods for HGR rarely focus on reducing memory load.To address this,we propose a memory-friendly CIL method for HGR using HD-sEMG.Our approach includes a lightweight convolutional neural network,named SeparaNet,for feature representation learning,coupled with a nearest-mean-of-exemplars classifier for classifi-cation.We introduce a priority exemplar selection algorithm inspired by the herding effect to maintain a manageable set of exemplars during training.Furthermore,a task-equal-weight exemplar sampling strategy is proposed to effectively reduce memory load while preserving high recognition performance.Experimental results on two datasets demonstrate that our method significantly reduces the number of retained exemplars to only a quarter of that required by other CIL methods,accounting for less than 5%of the total samples,while still achieving comparable average accuracy.展开更多
Tactile and proprioception feedback are essential to myoelectric hand prostheses control for regaining functionality of lost hands of amputees.Current studies focus on tactile feedback,while the lack of appropriate mu...Tactile and proprioception feedback are essential to myoelectric hand prostheses control for regaining functionality of lost hands of amputees.Current studies focus on tactile feedback,while the lack of appropriate multisensory feedback,especially proprioception feedback,limits the grasping quality.Additionally,a typical non-invasive stimulation scheme for sensation feedback uses stimulation on the stationary site of the skin continuously,which can lead to fatigue and adaptation of sensation,further reduces the feedback consistency,and increases the cognitive burden for the subject.Considering the sensitivity and modality matching of sensation,this study presented a multimodal sensations feedback scheme based on hybrid static-dynamic sensation elicited by multisite Transcutaneous Electrical Nerve Stimulation(TENS)to deliver grasping force and joint position feedback.In the proposed scheme,stimulation of single electrode produced only in-loco tactile sensation under the electrode,and the sensation intensity was adjusted according to grasping force;sequential activation of multi-electrodes produced an illusion dynamic sensation of a stimulus moving,and the velocity and direction of movement were adjusted according to finger joint position.Psychometric test results demonstrated the identifiability of stimulus in the proposed scheme.Further,prosthetic hand closed-loop grasping tasks evaluate the effectiveness of the proposed feedback scheme.The results showed that the proposed feedback scheme could substantially improve the grasping accuracy and efficiency.In addition,the study outcomes also demonstrated the benefit of artificial proprioception feedback in grasping rapidity and security.展开更多
The lack of an effective medical treatment for gastroparesis has pushed the research of new techniques of gastric electrical stimulation (GES) for nearly half a century of experimentation with a large variety of elect...The lack of an effective medical treatment for gastroparesis has pushed the research of new techniques of gastric electrical stimulation (GES) for nearly half a century of experimentation with a large variety of electrical stimuli delivered to the gastric wall of animals and patients with gastroparesis. Three principal methods are currently available: gastric low-frequency/high-energy GES with long pulse stimulation, high-frequency/low-energy GES with short pulse stimulation and neural sequential GES. The first method aims to reset a regular slow wave rhythm, but has variable effects on contractions and requires devices with large and heavy batteries unsuitable for implantation. High-frequency/low-energy GES, although inadequate to restore a normal gastric electro-mechanical activity, improves dyspeptic symptoms, such as nausea and vomiting, giving patients a better quality of life together with a more satisfactory nutritional status and is suitable for implantation. Unfortunately, the numerous clinical studies using this type of GES, with the exception of two, were not controlled and there is a need for definitive verification of the effectiveness of this technique to justify the cost and the risks of this procedure. The last method, which is neural sequential GES, consists of a microprocessor-controlled sequential activation of a series of annular electrodes along the distal two thirds of the stomach and is able to induce propagated contractions causing forceful emptying of the gastric content. The latter method is the most promising, but has been used only in animals and needs to be tested in patients with gastroparesis before it is regarded as a solution for this disease.展开更多
Targeted muscle reinnervation has been proposed for reconstruction of neuromuscular function in amputees.However,it is unknown whether performing delayed targeted muscle reinnervation after nerve injury will affect re...Targeted muscle reinnervation has been proposed for reconstruction of neuromuscular function in amputees.However,it is unknown whether performing delayed targeted muscle reinnervation after nerve injury will affect restoration of function.In this rat nerve injury study,the median and musculocutaneous nerves of the forelimb were transected.The proximal median nerve stump was sutured to the distal musculocutaneous nerve stump immediately and 2 and 4 weeks after surgery to reinnervate the biceps brachii.After targeted muscle reinnervation,intramuscular myoelectric signals from the biceps brachii were recorded.Signal amplitude gradually increased with time.Biceps brachii myoelectric signals and muscle fiber morphology and grooming behavior did not significantly differ among rats subjected to delayed target muscle innervation for different periods.Targeted muscle reinnervation delayed for 4 weeks can acquire the same nerve function restoration effect as that of immediate reinnervation.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 study the direct correlation between gastric dysrhythrnias and in vivo gastric muscle tone. METHODS： Five healthy dogs were implanted with 4 pairs of electrodes along the greater curvature, with a strain gau...AIM： To study the direct correlation between gastric dysrhythrnias and in vivo gastric muscle tone. METHODS： Five healthy dogs were implanted with 4 pairs of electrodes along the greater curvature, with a strain gauge （SG） being sutured parallel to the distal electrodes （2 cm above the pylorus）. Intravenous vasopressin was given to induce gastric dysrhythrnia. The percentage of regular slow waves and SG energy were calculated. RESULTS： （1） the regularity of gastric rnyoelectric activity （GMA） was reduced during and after infusion of vasopressin; （2） SG energy was significantly decreased during the infusion of vasopressin; （3） the decrease in SG energy was well correlated with the reduction in GMA regularity; （4） SG energy was negatively correlated with bradygastria and tachygastria. CONCLUSION： Vasopressin inhibits gastric contractions and impairs gastric slow waves; gastric dysrhythrnias are associated with the reduced antral muscle contractions, and are indicative of antral hypornotility.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 admi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
Fabric electrode is an emerging electrode element;due to some of its advantages, it can replace traditional conductive gel to become the next generation of electrode. This paper starts from the definition of fabric el...Fabric electrode is an emerging electrode element;due to some of its advantages, it can replace traditional conductive gel to become the next generation of electrode. This paper starts from the definition of fabric electrode, introduces the definition and working principle of fabric electrode, materials of producing electrodes preparation methods, and highlights the fabric used in the myoelectric prosthetic electrodes, supercapacitors and ECG tests.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
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
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
Purpose–Two-handed automobile steering at low vehicle speeds may lead to reduced steering ability at large steering wheel angles and shoulder injury at high steering wheel rates(SWRs).As afirst step toward solving the...Purpose–Two-handed automobile steering at low vehicle speeds may lead to reduced steering ability at large steering wheel angles and shoulder injury at high steering wheel rates(SWRs).As afirst step toward solving these problems,this study aims,firstly,to design a surface electromyography(sEMG)controlled steering assistance interface that enables hands-free steering wheel rotation and,secondly,to validate the effect of this rotation on path-following accuracy.Design/methodology/approach–A total of 24 drivers used biceps brachii sEMG signals to control the steering assistance interface at a maximized SWR in three driving simulator scenarios:U-turn,908 turn and 458 turn.For comparison,the scenarios were repeated with a slower SWR and a game steering wheel in place of the steering assistance interface.The path-following accuracy of the steering assistance interface would be validated if it was at least comparable to that of the game steering wheel.Findings–Overall,the steering assistance interface with a maximized SWR was comparable to a game steering wheel.For the U-turn,908 turn and 458 turn,the sEMG-based human–machine interface(HMI)had median lateral errors of 0.55,0.3 and 0.2 m,respectively,whereas the game steering wheel,respectively,had median lateral errors of 0.7,0.4 and 0.3 m.The higher accuracy of the sEMG-based HMI was statistically significant in the case of the U-turn.Originality/value–Although production automobiles do not use sEMG-based HMIs,and few studies have proposed sEMG controlled steering,the results of the current study warrant further development of a sEMG-based HMI for an actual automobile.展开更多
Upper limb loss results in significant physical and psychological impairment and is a major financial burden for both patients and healthcare services.Current myoelectric prostheses rely on electromyographic(EMG)signa...Upper limb loss results in significant physical and psychological impairment and is a major financial burden for both patients and healthcare services.Current myoelectric prostheses rely on electromyographic(EMG)signals captured using surface electrodes placed directly over antagonistic muscles in the residual stump to drive a single degree of freedom in the prosthetic limb(e.g.,hand open and close).In the absence of the appropriate muscle groups,patients rely on activation of biceps/triceps muscles alone(together with a mode switch)to control all degrees of freedom of the prosthesis.This is a non-physiological method of control since it is non-intuitive and contributes poorly to daily function.This leads to the high rate of prosthetic abandonment.Targeted muscle reinnervation(TMR)reroutes the ends of nerves in the amputation stump to nerves innervating“spare”muscles in the amputation stump or chest wall.These then become proxies for the missing muscles in the amputated limb.TMR has revolutionised prosthetic control,especially for high-level amputees(e.g.,after shoulder disarticulation),resulting in more intuitive,fluid control of the prosthesis.TMR can also reduce the intensity of symptoms such as neuroma and phantom limb pain.Regenerative peripheral nerve interface(RPNI)is another technique for increasing the number of control signals without the limitations of finding suitable target muscles imposed by TMR.This involves wrapping a block of muscle around the free nerve ending,providing the regenerating axons with a target organ for reinnervation.These RPNIs act as signal amplifiers of the previously severed nerves and their EMG signals can be used to control prosthetic limbs.RPNI can also reduce neuroma and phantom limb pain.In this review article,we discuss the surgical technique of TMR and RPNI and present outcomes from our experience with TMR.展开更多
基金supported by the National Climbing Program (No．95-Ⅷ-19-222)； the National Natural science Foundation of China(No．39770285)
文摘OBJECTIVE: To determine the effect of the area postrema (AP) of the medulla oblongata on gastrointestinal interdigestive migrating motor complex (MMC) and the plasma motilin level. METHODS: Interdigestive MMC activities of the antrum and duodenum were recorded by strain gauge implanted on the serosa of 8 conscious dogs. A cannula was intubated in femoral vein for motilin injection. The plasma motilin concentration was measured by RIA. We observed: (1) normal interdigestive MMC activity and fluctuations in plasma motilin concentration; (2) the effects of electrically damaging the AP on MMC activity and plasma motilin level; (3) whether intravenous injection of motilin could induce phase III contractions after the AP was destroyed. RESULTS: (1) Typical interdigestive MMC with phase I, II, III, and IV was recorded in normal dogs. Phase III was concurrent with the peak of plasma motilin level. (2) In damaged AP dogs, antroduodenal interdigestive MMC contractions were suppressed; cyclic, phasic and migratory pattern of MMC was disrupted. Plasma motilin concentration was decreased. Intravenous injection of motilin could not induce phase III contractions. CONCLUSIONS: The area postrema might play an important role, which is mediated by motilin, on the regulation of interdigestive MMC.
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.
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This work is supported by National Natural Science Foundation of China （Grant Nos. 51575187 and 91223201）, Science and Technology Program of Guangzhou （Grant No. 2014Y2-00217）, Science and Technology Major Project of Huangpu District of Guang-Zhou （Grant No, 20150000661）, the Fundamental Research Funds for the Central University （Grant No. 2015ZZ007） and Natural Science Foundation of Guangdong Province （Grant No. S2013030013355）.
文摘This paper presents an anthropomorphic prosthetic hand using flexure hinges, which is controlled by the surface electromyography （sEMG） signals from 2 electrodes only. The prosthetic hand has compact structure with 5 fingers and 4 Degree of Freedoms （DoFs） driven by 4 independent actuators. Helical springs are used as elastic joints and the joints of each finger are coupled by tendons. The myoelectric control system which can classify 8 prehensile hand gestures is built. Pattern recognition is employed where Mean Absolute Value （MAV）, Variance （VAR）, the fourth-order Autoregressive （AR） coefficient and Sample Entropy （SE） are chosen as the optimal feature set and Linear Discriminant Analysis （LDA） is utilized to reduce the dimension. A decision of hand gestures is generated by LDA classifier after the current projected feature set and the previous one are ＂pre-smoothed＂, and then the final decision is obtained when the current decision and previous decisions are ＂post-smoothed＂ from the decisions flow. The prosthetic hand can perform prehensile postures for activities of daily living and carry objects under the control of EMG signals.
基金supported in part by the National Key Research and Development Program of China under Grant 2021YFF1200600in part by the National Natural Science Foundation of China under Grant 62301523.
文摘Hand gesture recognition(HGR)plays a vital role in human-computer interaction.The integration of high-density surface electromyography(HD-sEMG)and deep neural networks(DNNs)has significantly improved the robustness and accuracy of HGR systems.These methods are typically effective for a fixed set of trained gestures.However,the need for new gesture classes over time poses a challenge.Introducing new classes to DNNs can lead to a substantial decrease in accuracy for previously learned tasks,a phenomenon known as“catastrophic forgetting,”especially when the training data for earlier tasks is not retained and retrained.This issue is exacerbated in embedded devices with limited storage,which struggle to store the large-scale data of HD-sEMG.Classincremental learning(CIL)is an effective method to reduce catastrophic forgetting.However,existing CIL methods for HGR rarely focus on reducing memory load.To address this,we propose a memory-friendly CIL method for HGR using HD-sEMG.Our approach includes a lightweight convolutional neural network,named SeparaNet,for feature representation learning,coupled with a nearest-mean-of-exemplars classifier for classifi-cation.We introduce a priority exemplar selection algorithm inspired by the herding effect to maintain a manageable set of exemplars during training.Furthermore,a task-equal-weight exemplar sampling strategy is proposed to effectively reduce memory load while preserving high recognition performance.Experimental results on two datasets demonstrate that our method significantly reduces the number of retained exemplars to only a quarter of that required by other CIL methods,accounting for less than 5%of the total samples,while still achieving comparable average accuracy.
基金supported by the National Key Research and Development Program of China(Grant No.2018YFB1307201)the National Natural Science Foundation of China(Grant Nos.51875120,91948302,U1813209).
文摘Tactile and proprioception feedback are essential to myoelectric hand prostheses control for regaining functionality of lost hands of amputees.Current studies focus on tactile feedback,while the lack of appropriate multisensory feedback,especially proprioception feedback,limits the grasping quality.Additionally,a typical non-invasive stimulation scheme for sensation feedback uses stimulation on the stationary site of the skin continuously,which can lead to fatigue and adaptation of sensation,further reduces the feedback consistency,and increases the cognitive burden for the subject.Considering the sensitivity and modality matching of sensation,this study presented a multimodal sensations feedback scheme based on hybrid static-dynamic sensation elicited by multisite Transcutaneous Electrical Nerve Stimulation(TENS)to deliver grasping force and joint position feedback.In the proposed scheme,stimulation of single electrode produced only in-loco tactile sensation under the electrode,and the sensation intensity was adjusted according to grasping force;sequential activation of multi-electrodes produced an illusion dynamic sensation of a stimulus moving,and the velocity and direction of movement were adjusted according to finger joint position.Psychometric test results demonstrated the identifiability of stimulus in the proposed scheme.Further,prosthetic hand closed-loop grasping tasks evaluate the effectiveness of the proposed feedback scheme.The results showed that the proposed feedback scheme could substantially improve the grasping accuracy and efficiency.In addition,the study outcomes also demonstrated the benefit of artificial proprioception feedback in grasping rapidity and security.
文摘The lack of an effective medical treatment for gastroparesis has pushed the research of new techniques of gastric electrical stimulation (GES) for nearly half a century of experimentation with a large variety of electrical stimuli delivered to the gastric wall of animals and patients with gastroparesis. Three principal methods are currently available: gastric low-frequency/high-energy GES with long pulse stimulation, high-frequency/low-energy GES with short pulse stimulation and neural sequential GES. The first method aims to reset a regular slow wave rhythm, but has variable effects on contractions and requires devices with large and heavy batteries unsuitable for implantation. High-frequency/low-energy GES, although inadequate to restore a normal gastric electro-mechanical activity, improves dyspeptic symptoms, such as nausea and vomiting, giving patients a better quality of life together with a more satisfactory nutritional status and is suitable for implantation. Unfortunately, the numerous clinical studies using this type of GES, with the exception of two, were not controlled and there is a need for definitive verification of the effectiveness of this technique to justify the cost and the risks of this procedure. The last method, which is neural sequential GES, consists of a microprocessor-controlled sequential activation of a series of annular electrodes along the distal two thirds of the stomach and is able to induce propagated contractions causing forceful emptying of the gastric content. The latter method is the most promising, but has been used only in animals and needs to be tested in patients with gastroparesis before it is regarded as a solution for this disease.
基金supported in part by the National Natural Science Foundation of China,Nos.U1913601,81927804the Key-Area Research and Development Program of Guangdong Province,No.2020B0909020004(GL)the National Natural Science Foundation of China,Nos.81960419,82260456(both to LY)。
文摘Targeted muscle reinnervation has been proposed for reconstruction of neuromuscular function in amputees.However,it is unknown whether performing delayed targeted muscle reinnervation after nerve injury will affect restoration of function.In this rat nerve injury study,the median and musculocutaneous nerves of the forelimb were transected.The proximal median nerve stump was sutured to the distal musculocutaneous nerve stump immediately and 2 and 4 weeks after surgery to reinnervate the biceps brachii.After targeted muscle reinnervation,intramuscular myoelectric signals from the biceps brachii were recorded.Signal amplitude gradually increased with time.Biceps brachii myoelectric signals and muscle fiber morphology and grooming behavior did not significantly differ among rats subjected to delayed target muscle innervation for different periods.Targeted muscle reinnervation delayed for 4 weeks can acquire the same nerve function restoration effect as that of immediate reinnervation.
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.
文摘AIM： To study the direct correlation between gastric dysrhythrnias and in vivo gastric muscle tone. METHODS： Five healthy dogs were implanted with 4 pairs of electrodes along the greater curvature, with a strain gauge （SG） being sutured parallel to the distal electrodes （2 cm above the pylorus）. Intravenous vasopressin was given to induce gastric dysrhythrnia. The percentage of regular slow waves and SG energy were calculated. RESULTS： （1） the regularity of gastric rnyoelectric activity （GMA） was reduced during and after infusion of vasopressin; （2） SG energy was significantly decreased during the infusion of vasopressin; （3） the decrease in SG energy was well correlated with the reduction in GMA regularity; （4） SG energy was negatively correlated with bradygastria and tachygastria. CONCLUSION： Vasopressin inhibits gastric contractions and impairs gastric slow waves; gastric dysrhythrnias are associated with the reduced antral muscle contractions, and are indicative of antral hypornotility.
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 admi
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Fabric electrode is an emerging electrode element;due to some of its advantages, it can replace traditional conductive gel to become the next generation of electrode. This paper starts from the definition of fabric electrode, introduces the definition and working principle of fabric electrode, materials of producing electrodes preparation methods, and highlights the fabric used in the myoelectric prosthetic electrodes, supercapacitors and ECG tests.
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.
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.
文摘Purpose–Two-handed automobile steering at low vehicle speeds may lead to reduced steering ability at large steering wheel angles and shoulder injury at high steering wheel rates(SWRs).As afirst step toward solving these problems,this study aims,firstly,to design a surface electromyography(sEMG)controlled steering assistance interface that enables hands-free steering wheel rotation and,secondly,to validate the effect of this rotation on path-following accuracy.Design/methodology/approach–A total of 24 drivers used biceps brachii sEMG signals to control the steering assistance interface at a maximized SWR in three driving simulator scenarios:U-turn,908 turn and 458 turn.For comparison,the scenarios were repeated with a slower SWR and a game steering wheel in place of the steering assistance interface.The path-following accuracy of the steering assistance interface would be validated if it was at least comparable to that of the game steering wheel.Findings–Overall,the steering assistance interface with a maximized SWR was comparable to a game steering wheel.For the U-turn,908 turn and 458 turn,the sEMG-based human–machine interface(HMI)had median lateral errors of 0.55,0.3 and 0.2 m,respectively,whereas the game steering wheel,respectively,had median lateral errors of 0.7,0.4 and 0.3 m.The higher accuracy of the sEMG-based HMI was statistically significant in the case of the U-turn.Originality/value–Although production automobiles do not use sEMG-based HMIs,and few studies have proposed sEMG controlled steering,the results of the current study warrant further development of a sEMG-based HMI for an actual automobile.
文摘Upper limb loss results in significant physical and psychological impairment and is a major financial burden for both patients and healthcare services.Current myoelectric prostheses rely on electromyographic(EMG)signals captured using surface electrodes placed directly over antagonistic muscles in the residual stump to drive a single degree of freedom in the prosthetic limb(e.g.,hand open and close).In the absence of the appropriate muscle groups,patients rely on activation of biceps/triceps muscles alone(together with a mode switch)to control all degrees of freedom of the prosthesis.This is a non-physiological method of control since it is non-intuitive and contributes poorly to daily function.This leads to the high rate of prosthetic abandonment.Targeted muscle reinnervation(TMR)reroutes the ends of nerves in the amputation stump to nerves innervating“spare”muscles in the amputation stump or chest wall.These then become proxies for the missing muscles in the amputated limb.TMR has revolutionised prosthetic control,especially for high-level amputees(e.g.,after shoulder disarticulation),resulting in more intuitive,fluid control of the prosthesis.TMR can also reduce the intensity of symptoms such as neuroma and phantom limb pain.Regenerative peripheral nerve interface(RPNI)is another technique for increasing the number of control signals without the limitations of finding suitable target muscles imposed by TMR.This involves wrapping a block of muscle around the free nerve ending,providing the regenerating axons with a target organ for reinnervation.These RPNIs act as signal amplifiers of the previously severed nerves and their EMG signals can be used to control prosthetic limbs.RPNI can also reduce neuroma and phantom limb pain.In this review article,we discuss the surgical technique of TMR and RPNI and present outcomes from our experience with TMR.
