ABSTRACT
In response to the problem that the traditional lower limb rehabilitation scale assessment method is time-consuming and difficult to use in exoskeleton rehabilitation training, this paper proposes a quantitative assessment method for lower limb walking ability based on lower limb exoskeleton robot training with multimodal synergistic information fusion. The method significantly improves the efficiency and reliability of the rehabilitation assessment process by introducing quantitative synergistic indicators fusing electrophysiological and kinematic level information. First, electromyographic and kinematic data of the lower extremity were collected from subjects trained to walk wearing an exoskeleton. Then, based on muscle synergy theory, a synergistic quantification algorithm was used to construct synergistic index features of electromyography and kinematics. Finally, the electrophysiological and kinematic level information was fused to build a modal feature fusion model and output the lower limb motor function score. The experimental results showed that the correlation coefficients of the constructed synergistic features of electromyography and kinematics with the clinical scale were 0.799 and 0.825, respectively. The results of the fused synergistic features in the K-nearest neighbor (KNN) model yielded higher correlation coefficients ( r = 0.921, P < 0.01). This method can modify the rehabilitation training mode of the exoskeleton robot according to the assessment results, which provides a basis for the synchronized assessment-training mode of "human in the loop" and provides a potential method for remote rehabilitation training and assessment of the lower extremity.
Subject(s)
Humans , Exoskeleton Device , Reproducibility of Results , Walking/physiology , Lower Extremity , Algorithms , Stroke Rehabilitation/methodsABSTRACT
Aiming at the human-computer interaction problem during the movement of the rehabilitation exoskeleton robot, this paper proposes an adaptive human-computer interaction control method based on real-time monitoring of human muscle state. Considering the efficiency of patient health monitoring and rehabilitation training, a new fatigue assessment algorithm was proposed. The method fully combined the human neuromuscular model, and used the relationship between the model parameter changes and the muscle state to achieve the classification of muscle fatigue state on the premise of ensuring the accuracy of the fatigue trend. In order to ensure the safety of human-computer interaction, a variable impedance control algorithm with this algorithm as the supervision link was proposed. On the basis of not adding redundant sensors, the evaluation algorithm was used as the perceptual decision-making link of the control system to monitor the muscle state in real time and carry out the robot control of fault-tolerant mechanism decision-making, so as to achieve the purpose of improving wearing comfort and improving the efficiency of rehabilitation training. Experiments show that the proposed human-computer interaction control method is effective and universal, and has broad application prospects.
Subject(s)
Humans , Exoskeleton Device , Muscle Fatigue , Muscles , Algorithms , Electric ImpedanceABSTRACT
With the advantage of providing more natural and flexible control manner, brain-computer interface systems based on motor imagery electroencephalogram (EEG) have been widely used in the field of human-machine interaction. However, due to the lower signal-noise ratio and poor spatial resolution of EEG signals, the decoding accuracy is relative low. To solve this problem, a novel convolutional neural network based on temporal-spatial feature learning (TSCNN) was proposed for motor imagery EEG decoding. Firstly, for the EEG signals preprocessed by band-pass filtering, a temporal-wise convolution layer and a spatial-wise convolution layer were respectively designed, and temporal-spatial features of motor imagery EEG were constructed. Then, 2-layer two-dimensional convolutional structures were adopted to learn abstract features from the raw temporal-spatial features. Finally, the softmax layer combined with the fully connected layer were used to perform decoding task from the extracted abstract features. The experimental results of the proposed method on the open dataset showed that the average decoding accuracy was 80.09%, which is approximately 13.75% and 10.99% higher than that of the state-of-the-art common spatial pattern (CSP) + support vector machine (SVM) and filter bank CSP (FBCSP) + SVM recognition methods, respectively. This demonstrates that the proposed method can significantly improve the reliability of motor imagery EEG decoding.
Subject(s)
Humans , Algorithms , Brain-Computer Interfaces , Electroencephalography , Imagination , Neural Networks, Computer , Reproducibility of ResultsABSTRACT
Artificial prosthesis is an important tool to help amputees to gain or partially obtain abled human limb functions. Compared with traditional prosthesis which is only for decoration or merely has feedforward control channel, the perception and feedback function of prosthesis is an important guarantee for its normal use and self-safety. And this includes the information of position, force, texture, roughness, temperature and so on. This paper mainly summarizes the development and current status of artificial prostheses in the field of perception and feedback technology in recent years, which is derived from two aspects: the recognition way of perception signals and the feedback way of perception signals. Among the part of recognition way of perception signals, the current commonly adopted sensors related to perception information acquisition and their application status in prosthesis are overviewed. Additionally, from the aspects of force feedback stimulation, invasive/non-invasive electrical stimulation, and vibration stimulation, the feedback methods of perception signals are summarized and analyzed. Finally, some problems existing in the perception and feedback technology of artificial prosthesis are proposed, and their development trends are also prospected.
Subject(s)
Humans , Amputees , Artificial Limbs , Feedback, Sensory , Prosthesis Design , Prosthesis ImplantationABSTRACT
BACKGROUND: Previous studies demonstrated that recombinant human bone morphogenetic pretein-7 (hBMP-7) can effectively promote the synthesis of extracellular matrix, repair of damaged disc matrix, restore of degenerative disc height. It is hoped that BMP-7 can be used to control and reverse the intervertebral disc degeneration. However, because of the short half-life of recombinant protein and low biological activity, it is difficult to maintain BMP-7 high concentrations on degenerative disc. Gene therapy can prevent these defects effectively.OBJECTIVE: To study the effect of hBMP-7 gene transfeotion on biological activity of primary cultured rabbit nucleus pulposus cells in vitro, to determine the feasibility of hBMP-7 gene which will on gene therapy research of intervertebral disc degeneration,and to provide basis for further study.DESIGN, TIME AND SETTING: A randomized and controlled observation was performed at the Institute of Cardiothoracic Surgery of Changhai Hospital from December 2005 to September 2006.MATERIALS: Six healthy New Zealand white rabbits of either gender, averaging 4 weeks old and weighing 500 g, were used in this study, and Ad-hBMP7 was constructed by the Cardiothoracic Surgery Institute of Changhai Hospital.METHODS: After rabbits sacrifice under aseptic condition, the nucleus pulposus was got. After digested with Pronase, type Ⅱcollagenase and type Ⅱ DNAase (4 hours, 37 "(2), the cells were seeded in the Petri dishes and were kept in the incubator. After 7 days and then twice a week, the media were refreshed. The nucleus pulposus cells were infected by adenovirus integrated with hBMP7 gene. The cells which were transfected by adenovirus vector for Lac-Z gene and which were not transfected were adopted as control.MAIN OUTCOME MEASURES: The expression of hBMP-7 was determined by RTopCR and Western blot. The effect of hBMP-7 on cell proliferation was surveyed by MTT. Furthermore, the effect of hBMP-7 gene on synthesis of proteoglycan and type Ⅱcollagen was detected by modified dimethylmethylene blue method and ELISA, respectively.RESULTS: Gene sequencing and PCR showed that hBMP-7 gene was inserted correctly and no mutation happened. The pdmary cultured rabbit nucleus pulposus cells were identical with those reported in literature. After Ad-hBMP7 transduct into the nucleus pulposus cells, high level of hBMP-7 expression was observed and lasted over 3 weeks. Also hBMP-7 gene can promote cell proliferation and synthesis of proteoglycan and type II collagen with significant difference compared with control groups (P < 0.05).CONCLUSION: hBMP-7 gene mediated by adenovirus can be the target gene for the further study on gene therapy of intervertebral disc degeneration.
ABSTRACT
BACKGROUND: The establishment of animal models is of important significance for understanding the pathogenesis, prevention, and treatment of intervertebral disc degeneration. OBJECTIVE: To develop rabbit models of intervertebral disc degeneration by acupuncture and to analyze the effects of acupuncture on intervertebral disc height and degeneration by X-ray and MRI examinations. DESIGN: A randomized and controlled observation. SETTING: Department of Orthopaedics, Changhai Hospital, Second Military Medical University of Chinese PLA. MATERIALS: This study was performed at the Animal Cener, Changhai Hospital, Second Military Medical University of Chonese PLA between June 2005 and April 2006. Six healthy New Zealand white rabbits of either gender, averaging 6 months old, weighing 2.5 kg on average, were provided by Animal Cener, Changhai Hospital, Second Military Medical University of Chinese PLA [permission No. SCXK (hu) 2002-0006], and recruited for this study. The protocol was performed in accordance with ethical guidelines for the use and care of animals.METHODS: ① Operation was made in experimental rabbits via the anterior retroperitoneal approach. The management for the intervertebral discs was as follows: L3-4 was the control disc without exposure or needle stab; L4-5 was subjected to sham-operation with only exposure; L5-6 was the experimental disc with three times of anterior-lateral needle stab after exposure. Lumbar lateral X-ray film was respectively taken with a CR machine (Simens Company) prior to and 4 weeks after surgery for measuring L3-4, L4-5, and L5-6 intervertebral disc height and calculating the ratio with intervertebral disc height prior to surgery. Each segmental lumbar intervertebral disc T2-weighted signal was measured with a 1.5 T medical superconductive magnetic resonance scanner (Simens Avanto). According to signal intensity, intervertebral disc degeneration was graded: a score of 4 indicated normal intervertebral disc without apparent degeneration but with bright signal, a score of 3 indicated slight degeneration with a little decrease in T2-weighted signal, a score of 2 indicated moderate degeneration with apparent decrease in T2-weighted signal, and a score of 1 indicated severe degeneration with apparent decrease in both T2-weighted signal and intervertebral disc height. MAIN OUTCOME MEASURES: Intervertebral disc height change revealed by lumbar lateral X-ray film; Intervertebral disc degeneration degree analyzed through magnetic resonance imaging (MRI) examination. RESULTS: All 6 experimental rabbits were included in the final analysis. The postsurgery-to-presurgery ratio of intervertebral disc height was 0.982 5±0.017 08 and 0.972 5±0.017 08 for L3-4 and L4-5 respectively, which was higher compared to that for L5-6 (0.550 0±0.02 582). Significant statistical difference existed (P ＜ 0.01). T2-weighted singal score was (4.00±0.0) and (3.75±0.5) for L3-4 and L4-5 intervertebral disc, respectively, which was higher compared to that for L5-6 intervertebral disc. Significant statistical difference existed (P ＜ 0.01). CONCLUSION: After 4 weeks of acupuncture, intervertebral disc height is decreased and interterbral disc degeneration obviously appears.
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AIM:In human being,the exposure of lumbar Intervertebral discs usually requires the anterior transperitoneal or lateral retroperitoneal approaches. To study the feasibility of retropedtoneal approach to the lumbar spine in the New Zealand white rabbits.METHODS: The experiment was carried out between April 2005 and April 2006 in the Animal Center of Changhai Hospital.Second Military Medical University of Chinese PLA.Thirty New Zealand white rabbits,aged 6 months old, of either gender, weighing 2.5 kg,provided by the Animal Center of Changhai Hospital,Second Military Medical University of Chinese PLA [permission No.SCXK (hu) 2002-0006],were used in this study.During the experiment,the management of animals corresponded to Animal Ethical Standard.This study was approved by the Experimental Animal Ethics Committee,Changhai Hospital,Second Military Medical University of Chinese PLA.Transperitoneal approach was used to exposure the lumbar spine of experimental rabbits. The skin was disassociated, and a blunt dissection was made backwardly along the juncture of the maximum back muscle and external oblique muscle of abdomen,and lumbar intervertebral disc was exposed gradually.Observation index:①Operative effect of exposure.②Postoperative general condition (food intake,urination and defecation,activity,incision healing and death or not).RESULTS: Thirty experimental rabbits were involved in the final analysis.①The operative effect of exposure:The dght retroperitoneal approach was chosen,with satisfactory anesthesia and excellent exposure of rabbit lateral lumbar spine. And the exposure was usually accomplished within 15 minutes, with Less bleeding and no retroperitoneal rupture. ②Postoperative general condition: All animals recovered their consciousnesses within about 1 hour. They were intravenously injected continuously for supplementing blood volume,and after that,they were raised in the separate cases and were allowed to move freeLy.On the day of operation.they were fasted and forbidden to access to water.Their appetites began to decrease on the postoperative 1 day.restored from the 3rd day postoperatively and restored to normal on the 40th day postoperatively.All animals survived until after 4 weeks.They could move freely,without paralysis occurred or incontinence. There was one experimental animal whose surgical Incision broke.Debridement and resuture were given, and its wound healed. In all the other animals, the surgical incision healed well.CONCLUSION: Retroperitoneal approach can give an excellent access to the lumbar spine with easy operation and less complications.
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Objective: To evaluate the efficacy of the third-generation instrumentation including TSRH, CD and ISOLA in the treatment of adult scoliosis. Methods:Thirty-five adult patients with idiopathic or degenerative scoliosis who received treatment with third-generation instrumentation (TSRH,CD and ISOLA) between July 1999 to January 2003 were retrospectively reviewed. The mean preoperative cobb angle of major curves of the frontal plane was 58.1°(42°-95°). The patients received a combined anteroposterior approach or a single posterior procedure. The mean follow-up time was 20 months(10-48 months). Preoperative and postoperative Cobb angles of the frontal plane and sagittal plane and the distance between C7 and CVLS were measured. The subjective assessment was judged by questionnaire. Results: Postoperative clinical appearance of all patients improved significantly. Mean correction of major curves of the coronal plane was 53.2%. Mean loss of correction of the coronal plane in the last follow-up was 4.3°. The distance between the midline of C7 and CVSL was corrected from 2.6 cm to 0.24 cm. The results of follow-up showed that 89.3% patients were satisfied with the outcome. Pneumatothorax and haematothorax occurred in 2 patients. Three patients still complained of low back pain one year after operation because of adjacent degeneration in 2 patients and pseudoarthrosis in the remaining 1 patient. Conclusion: Imageologic findings and subjective assessment of the patients showed that the third-generation instrumentation can achieve good correction and trunk balance in the treatment of adult scoliosis with fewer complications.