High-density channels are often used to acquire electroencephalogram (EEG) spatial information in different cortical regions of the brain in brain-computer interface (BCI) systems. However, applying excessive channels is inconvenient for signal acquisition, and it may bring artifacts. To avoid these defects, the common spatial pattern (CSP) algorithm was used for channel selection and a selection criteria based on norm-2 is proposed in this paper. The channels with the highest M scores were selected for the purpose of using fewer channels to acquire similar rate with high density channels. The DatasetⅢa from BCI competition 2005 were used for comparing the classification accuracies of three motor imagery between whole channels and the selected channels with the present proposed method. The experimental results showed that the classification accuracies of three subjects using the 20 channels selected with the present method were all higher than the classification accuracies using all 60 channels, which convinced that our method could be more effective and useful.
Clinical trial transparency, include clinical trial registration, unbiased reporting results and sharing individual participant data (IPD), is one of the most important revolutionary concepts following clinical epidemiology and evidence-based medicine in the medical field. Sharing IPD is a medical ethics issue reflected a new sense of worth and constructing new rules of clinical trials. Our viewpoint is that from the essential purpose of clinical research, IPD is a social public property. Sharing IPD is a one of the best ways for respecting the contributions of the participants, and one of the keys for changing face of clinical trials.
Neurofeedback (NF) technology based on electroencephalogram (EEG) data or functional magnetic resonance imaging (fMRI) has been widely studied and applied. In contrast, functional near infrared spectroscopy (fNIRS) has become a new technique in NF research in recent years. fNIRS is a neuroimaging technology based on hemodynamics, which has the advantages of low cost, good portability and high spatial resolution, and is more suitable for use in natural environments. At present, there is a lack of comprehensive review on fNIRS-NF technology (fNIRS-NF) in China. In order to provide a reference for the research of fNIRS-NF technology, this paper first describes the principle, key technologies and applications of fNIRS-NF, and focuses on the application of fNIRS-NF. Finally, the future development trend of fNIRS-NF is prospected and summarized. In conclusion, this paper summarizes fNIRS-NF technology and its application, and concludes that fNIRS-NF technology has potential practicability in neurological diseases and related fields. fNIRS can be used as a good method for NF training. This paper is expected to provide reference information for the development of fNIRS-NF technology.
ObjectiveTo investigate the disinfection effect of dry-fogging hydrogen peroxide (DFHP) on ambulance inner surfaces.MethodsThis study was carried out using simulated field test and field test from October to December 2018. In the simulated field test, the carriers with Geobacillus stearothemopilus (ATCC12980) spores were placed in 6 places in the ambulance, and disinfected for 60 minutes with DFHP of 0.38–0.72 g/m3. The carriers were cultured for up to 7 days to observe whether the bacteria were eliminated. Before and after the DFHP disinfection, the microbial sampling of the surface in the ambulance was carried out, and the colonies were counted after the cultivation.ResultsThe eliminating rate of the bacteria carriers on the uncovered surface was 100% (20/20), and that of the covered surface was 10% (1/10). The pass rate of microbial sampling was 100% (26/26).ConclusionsThe DFHP had a significant decontamination effect on the ambulance inner uncovered surfaces. The DFHP equipment is automated and their disinfecting quality is consistent, therefore it is suitable for the disinfection of ambulance inner surfaces. But the limitation of disinfection effect on covered surfaces should be avoided.
A total of 12 cases of old facet dislocations of cervical spine treated between december 1988 and 1993 were analyzed in order to evaluate the efficacy of various surgical modalities. In this series, there were 8 males and 4 females, with ages ranged from 16 to 50 years old (averaged 37.8 years old). The duration from injury to admission to our hospital was ranged from 1 to 8 months (averaged 3.7 months). Dislocation levels were as follows: C3,4 in 1 case, C4,5 in 4 cases, C5,6 in 4 cases and C6,7 in 3 cases. Unilateral facet dislocation was in 7 cases and bilateral facet dislocation in 5 cases. Neurological status on admission was as follows: spinal cord and nerve root lesion in 5 cases, nerve root lesion alone in 5 cases and neurologically intact in 2 cases. Besides all facets receiving facetectomy and iliac bone graft, other four kinds of adjuvant treatments were used, including internal fixation by stainless wires laminae or spinous processes in 4 cases, Luque rod in 1 cases, anterior fibrolysis combined with posterior laminoplasty in 1 cases and sustained skull traction without internal fixation in 6 cases. The reduction efficacy from postoperative stustained skull traction was better and the stainless wires fixation ranked the next. The patients only suffering from the nerve root lesion recovered better, but those who had spinal cord combined with nerve root lesion recovered badly. In conclusion, for the treatment of old facet dislocation, it is necessary to resect the facet and graft with iliac bone.
As a complex system, the topology of human’s brain network has an important effect on further study of brain’s structural and functional mechanism. Graph theory, a kind of sophisticated analytic strategies, is widely used for analyzing complex brain networks effectively and comparing difference of topological structure alteration in normal development and pathological condition. For the purpose of using this analysis methodology efficiently, it is necessary to develop graph-based visualization software. Thus, we developed VisConnectome, which displays analysis results of the brain network friendly and intuitively. It provides an original graphical user interface (GUI) including the tool window, tool bar and innovative double slider filter, brain region bar, runs in any Windows operating system and doesn’t rely on any platform such as Matlab. When importing the user-defined script file that initializes the brain network, VisConnectome abstracts the brain network to the ball-and-stick model and render it. VisConnectome allows a series of visual operations, such as identifying nodes and connection, modifying properties of nodes and connection such as color and size with the color palette and size double slider, imaging the brain regions, filtering the brain network according to its size property in a specific domain as simplification and blending with the brain surface as a context of the brain network. Through experiment and analysis, we conclude that VisConnectome is an effective visualization software with high speed and quality, which helps researchers to visualize and compare the structural and functional brain networks flexibly.
Objective To analyze the distribution of stress in the upper and lower plates of the prosthesis-bone interface, and the effect of interface pressure on osseointegration. Methods CT scanning was performed on goats at 1 week after artificial cervical disc replacement to establish the finite element model of C3, 4. The stress distribution of the upper and lower plates of the interface was observed. At 6 and 12 months after replacement, Micro-CT scan and three dimensional reconstruction were performed to measure the bone volume fraction (BVF), trabecular number (Tb. N), trabecular thickness (Tb. Th), trabecular separation (Tb. Sp), bone mineral density (BMD), bone surface/bone volume (BS/BV), and trabecular pattern factor (Tb. Pf). The C3 lower plate and C4 upper plate of 4 normal goat were chosen to made the cylinder of the diameter of 2 mm. The gene expressions of receptor activator for nuclear factor κB ligand (RANKL), osteoprotegerin (OPG), transforming growth factor β (TGF-β), and macrophage colony-stimulating factor (M-CSF) were detected by real time fluorescent quantitative PCR at immediate after cutting and at 24 and 48 hours after culture. The samples of appropriate culture time were selected to made mechanical loading, and the gene expressions of RANKL, OPG, M-CSF, and TGF-β were detected by real time fluorescent quantitative PCR; no mechanical loading samples were used as normal controls. Results Under 25 N axial loading, the stress of the upper plate of C3, 4 was concentrated to post median region, and the stress of the lower plate to middle-front region and two orbits. According to stress, the plate was divided into 5 regions. The Micro-CT scan showed that BMD, Tb.Th, BVF, and Tb.N significantly increased, and BS/BV, Tb.Sp, and Tb.Pf significantly decreased at 12 months after replacement when compared with ones at 6 months (P<0.05). At 24 and 48 hours after culture, the gene expressions of RANKL, OPG, and TGF-β were signifi-cantly higher than those at immediate (P<0.05), but no significant difference was found between at 24 and 48 hours after culture (P>0.05). The mechanical loading test results at 24 hours after culture showed that the RANKL and OPG gene expressions and OPG/RANKL ratio in C3 lower plate and C4 upper plate were significantly up-regulated when compared with controls (P<0.05), but no significant difference was shown in TGF-β and M-CSF gene expressions (P>0.05). Conclusion Domestic artificial cervical disc endplate has different pressure distribution, the stress of lower plate is higher than that of upper plate. Pressure has important effect on local osseointegration; the higher pressure area is, the osseointegration is better. Under the maximum pressure in interface, the osteoblast proliferation will increase, which is advantageous to the local osseointegration.
ObjectiveTo review the research status of anti-infective graft materials and analyze their application prospects, in order to provide inspiration for the development of anti-infective vascular endograft. MethodThe research on endovascular anti-infective grafts at home and abroad was reviewed. ResultsThe anti-infective capability of endovascular graft could be achieved through main approaches like modification of the bulk material, surface modification, or a combination of both. In terms of bulk material modification, this paper delved into the creation of antibacterial composite materials by incorporating other materials into primary materials like metals (such as Mg, Zn), biologically derived materials (such as chitosan, silk fibroin, bacterial cellulose), and synthetic polymers (such as graphene and its derivatives, polyurethane, polylactic acid). Examples included Mg-Nd-Zn-Zr alloy, bacterial cellulose/chitosan nanocrystal composites, and chitosan/silk fibroin composites. For surface modifications, inorganic coatings (such as silver, copper, and nitrides) and organic coatings (such as antibiotics, antimicrobial peptides, and anti-infection polymers) had shown promising antibacterial effects in experiments. ConclusionsThe future research focus is how to synthesize the composite graft material with the mechanical properties of ordinary graft and the cell, blood compatibility and antibacterial properties through nano technology. At the same time, how to synthesize coatings with stable long-term anti-infection and anti-bacterial biofilm performance is also considered to be an important direction of future research.
Wearing transfemoral prosthesis is the only way to complete daily physical activity for amputees. Motion pattern recognition is important for the control of prosthesis, especially in the recognizing swing phase and stance phase. In this paper, it is reported that surface electromyography (sEMG) signal is used in swing and stance phase recognition. sEMG signal of related muscles was sampled by Infiniti of a Canadian company. The sEMG signal was then filtered by weighted filtering window and analyzed by height permitted window. The starting time of stance phase and swing phase is determined through analyzing special muscles. The sEMG signal of rectus femoris was used in stance phase recognition and sEMG signal of tibialis anterior is used in swing phase recognition. In a certain tolerating range, the double windows theory, including weighted filtering window and height permitted window, can reach a high accuracy rate. Through experiments, the real walking consciousness of the people was reflected by sEMG signal of related muscles. Using related muscles to recognize swing and stance phase is reachable. The theory used in this paper is useful for analyzing sEMG signal and actual prosthesis control.
Brain-computer interface (BCI) is a revolutionizing human-computer Interaction, which is developing towards the direction of intelligent brain-computer interaction and brain-computer intelligent integration. However, the practical application of BCI is facing great challenges. The maturity of BCI technology has not yet reached the needs of users. The traditional design method of BCI needs to be improved. It is necessary to pay attention to BCI human factors engineering, which plays an important role in narrowing the gap between research and practical application, but it has not attracted enough attention and has not been specifically discussed in depth. Aiming at BCI human factors engineering, this article expounds the design requirements (from users), design ideas, objectives and methods, as well as evaluation indexes of BCI with the human-centred-design. BCI human factors engineering is expected to make BCI system design under different use conditions more in line with human characteristics, abilities and needs, improve the user satisfaction of BCI system, enhance the user experience of BCI system, improve the intelligence of BCI, and make BCI move towards practical application.
