ABSTRACT
Objective To evaluate the characteristics of spatial distribution and time accumulation of impact acceleration at different parts of human body during backward falling process. Methods Four healthy men and four healthy women (20-20 years old) were enrolled. The tri-axial acceleration on head, chest, left/right arm/hand/foot, left/right front/back hip, left/right femur head, sacrum and coccyx throughout the backward falling were measured by ADXL335 tri-axial acceleration sensor. Systemic acceleration distribution of backward falling was polynomial fitted by signal magnitude vector (SMV) of its first peak. Besides, parameters of impulse mechanics such as zero-g time, total falling time, peak SMV, relative pressure impulse of the vulnerable sites (head, hip and its related sites) were also calculated. Results Compared with the other parts of the body, the peak SMV and relative impulses of left/right back hip and head were significantly higher (P＜0.05). Acceleration that paralleled to the ground in left/right back hip was also relatively large. The rotational transform angles of left/right back hip, left/right femur head, sacrum and coccyx were significantly larger (P＜0.05). In addition, during the process of falling backward to the ground, a sliding tendency toward the sagittal plane 53.58°±6.75° occurred at all testing sites. Conclusions Head and hips are vulnerable during backward falling, and their zero-g time (0.26±0.05) s can be used as the longest starting time of falling protection devices. The large change angle of left/right hip, left/right femoral head, sacrum and coccyx may be the important cause of the sprain during backward falling.
ABSTRACT
A Web-based technology system was put forward aiming at the actual problems of the long maintenance cycle and the difficulties of the maintenance and repairing of medical equipments. Based on analysis of platform system structure and function, using the key technologies such as search engine, BBS, knowledge base and etc, a platform for medical equipment service technician to use by online or offline was designed. The platform provides users with knowledge services and interactive services, enabling users to get a more ideal solution.
Subject(s)
Equipment and Supplies , Internet , Knowledge Bases , MaintenanceABSTRACT
Objective To lateralize epileptic foci in interictal electroencephalography (EEG) signal by using causal analysis method.Methods On the basis of frequency domain causal analysis,the adapted directed transfer function (ADTF),power spectrum weighted ADTF(psADTF) method was proposed by applying the power spectrum information in defined frequency band with normalized ADTF,to fit the frequency information features of different epileptic wave.EEG signals of two groups of 30 epilepsy patients were analyzed by psADTF.Group Ⅰ included 15 presurgical patients and 104 epilepsy spikes were picked from EEG signals.Group Ⅱ included 15 outpatient patients and 98 epilepsy spikes were picked from EEG signals.Results 96 of 104 spikes of group Ⅰ were lateralized properly by psADTF according to surgery sites,and the accuracy rate was 92％.94 of 98 spikes of group Ⅱ were lateralized properly by psADTF according to three technicians' judgments,with the accuracy rate of 96％.Conclusion Our results proves that the psADTF method over interictal EEG spikes can be a great help to clinical epileptic foci lateralization.
ABSTRACT
The power and signal transmission technology is one of the key technologies in neuroprosthetic research. This paper proposes firstly the related theory of power and signal transmission technology in neuroprosthetic, then summarizes the three key aspects of the power and signal transmission technology in neuroprosthetic. After analyzed the development of the inductive wireless power harvesting technology, the wireless telemetry technology and the wireless power harvesting telemetry technology, the emphasis on research contents will be proposed and discussed, which will help accelerate the further research of prosthetic.
Subject(s)
Humans , Electric Power Supplies , Electrodes, Implanted , Neural Prostheses , Prosthesis Design , Signal Processing, Computer-Assisted , Telemetry , Wireless TechnologyABSTRACT
How does brain select and adjust the distributed neural activities to achieve its function? To address this problem,researchers introduce Granger causality analysis method to brain functional study,which deals with the estimation of causal influences among multi-variables.First,basic principles of Granger Causality and its improved algorithm structural vector autoregression (SVAR) are introduced.Then several technical problems are reviewed which should be noted when analyzing brain functional signals by Granger Causality Methods.In the end,the application foreground of Granger Causality in epilepsy localization is introduced by taking idiopathic generalized epilepsy as the example.
ABSTRACT
Feedback is an important way of information transmission in motor function output. Movement-related information can be transmitted as proprioceptive, haptic, visual and/or audial information to the central nervous system for control and modification of the temporal and spatial precision of motor output. Here presented is a systematic discussion on the principle, technique and effect for some typical motor function rehabilitation methods such as treatment based on EMG feedback, robot-aided movement therapy, high-level perceptional feedback and motor training effect with 3-D virtual reality environment.
Subject(s)
Humans , Feedback, Psychological , Motor Activity , Physiology , Motor Skills Disorders , Rehabilitation , Stroke , Stroke Rehabilitation , Therapy, Computer-Assisted , User-Computer InterfaceABSTRACT
A method for the suppression of geomagnetic field interference is here-in introduced. It is designed for use in the magnet locating system of the engineering-based microcapsule inside the alimentary tract. This method marks the geomagnetic field interference levels by getting the static value. Then subtracting the static value from the dynamic value. The results of the experiment show that the method can assess the geomagnetic fi eld interference levels around thelocating waistcoat accurately. And the three-dimensional tracking trajectory shows that the method has greatly improved the accuracy of the capsule location inside the alimentary tract.
Subject(s)
Humans , Biosensing Techniques , Capsule Endoscopy , Economics , Methods , Computer Simulation , Electromagnetic Fields , Equipment Design , Gastrointestinal Tract , Physiology , Magnetics , Phantoms, ImagingABSTRACT
Objective To explore the correlation between the moving angle of elbow joint and surface electromyogram signal(sEMG)activities of biceps and triceps.Methods The eigenvalue of sEMG during elbow joint moving under constant load were calculated with means of root mean square(RMS)and integrated electromyogram(iEMG)in time domain.Results The experimental results showed that both the chavacteristics of RMS and iEMG for biceps differed from those of triceps.The sEMG activities of biceps increased with the increment of elbow joint angle,while those from triceps reached to the maximum values when elbow joint angle was 90?.Furthermore,the sEMG activities of triceps at the elbow angle of 45? was similar with that when elbow angle was 135?.Conclusion The sEMG from biceps and triceps can reflect the moving angle of elbow joint under constant load.
ABSTRACT
Objective To study the relationship between handgrip level and characteristics of surface electromyogram(sEMG)signal from forearm muscles.Methods Nine healthy volunteers were asked to do a specific grip test with three force levels of maximum volunteer contraction(MVC),80% MVC and 40% MVC.sEMG signal was recorded from flex digitorum superficial(FDS)and extensor carpi radialis longus(ECRL)simultaneously.The amplitude characteristics of sEMG signal were calculated by the means of root mean square(RMS)and wavelet analysis.Furthermore,to compare the relationship of sEMG and force level between different participants,SPSS was applied to analyze the relative value that was defined as the ratio between sEMG characteristics of MVC condition and that of different grip levels.Results There existed positive correlation between grip level and sEMG activity,stronger grip corresponded the greater sEMG characteristics for every participant,and this correlation revealed significant coherence between different volunteers.Conclusion There is significant correlation between grip force and forearm muscle activities represented as sEMG characteristics.The result suggests that sEMG can be used to predict grip force noninvasively for measuring motor function and assessing the motor function rehabilitation.
ABSTRACT
The statistical characteristic is the key to image compression. Here we have studied the statistical characteristic of wavelet subimage, and designed a new image quantization algorithm referred to statistical characteristics of both wavelet subimage and human visual.
Subject(s)
Algorithms , Image Processing, Computer-Assisted , Methods , Linear Models , TeleradiologyABSTRACT
The compression of medical image is the key to study tele-medicine & PACS. We have studied the statistical distribution of wavelet subimage coefficients and concluded that the distribution of wavelet subimage coefficients is very much similar to that of Laplacian distribution. Based on the statistical properties of image wavelet decomposition, an image quantization algorithm is proposed. In this algorithm, we selected the sample-standard-deviation as the key quantization threshold in every wavelet subimage. The test has proved that, the main advantages of this algorithm are simple computing and the predictability of coefficients in different quantization threshold range. Also, high compression efficiency can be obtained. Therefore, this algorithm can be potentially used in tele-medicine and PACS.
Subject(s)
Algorithms , Image Processing, Computer-Assisted , Methods , Linear ModelsABSTRACT
Body-surface electrogastrogram signals can be adopted in studies of gastrodynamics characteristics and diagnoses of functional gastric diseases. Fundamental theory of denoise by wavelet introduced, wavelet transfer is applied to the denoise of body-surface electrogastrogram signals. The high-frequency noise is eliminated through wavelet, and thus the SNR and the resolution ratio of the signal are increased.
ABSTRACT
It is necessary to build a three-dimensional human body model to display the position and track the route of a micro device inside the human body exactly. The key is to construct a three-dimensional human body model according to the patient characteristic. This paper gives a simple way to build the personal geometric model based on the OpenGL programming in the Visual Basic environment. It is proved that the method contributes to the realtime interactive operation to change the model character according to the individual parameter.