Steady-state visual evoked potential (SSVEP) is one of the commonly used control signals in brain-computer interface (BCI) systems. The SSVEP-based BCI has the advantages of high information transmission rate and short training time, which has become an important branch of BCI research field. In this review paper, the main progress on frequency recognition algorithm for SSVEP in past five years are summarized from three aspects, i.e., unsupervised learning algorithms, supervised learning algorithms and deep learning algorithms. Finally, some frontier topics and potential directions are explored.
Objective To analyze the current status and hotspots of surgical transmural ablation of atrial fibrillation using CiteSpace and VOSviewer. MethodsThe Web of Science Core Collection database was used as the data source. The CiteSpace 5.8.R3 and VOSviewer software were used to analyze the related studies on surgical transmural ablation of atrial fibrillation about the authors, countries/institutions, literature co-citation and keywords. Results A total of 109 articles were enrolled. Damiano RJ was the most prolific researcher, while Cox JL was the author with the highest number of citations. The United States was the leading country in this research field. The University of Washington was an important institution in the study of atrial fibrillation transmural ablation. The main hotpots were the effectiveness of surgical ablation, especially Cox-maze procedure, selection of the energy source of surgical ablation, combination of surgical and catheter ablations, and pulmonary vein isolation. ConclusionThis study visualizes the current research status of surgical ablation of atrial fibrillation. How to improve the effectiveness and transmurality of surgical ablation is a hot research topic in the surgical treatment of atrial fibrillation. The combination of electrophysiology mapping and surgical ablation may be the development direction in the surgical treatment of atrial fibrillation.
Brain computer interface is a control system between brain and outside devices by transforming electroencephalogram (EEG) signal. The brain computer interface system does not depend on the normal output pathways, such as peripheral nerve and muscle tissue, so it can provide a new way of the communication control for paralysis or nerve muscle damaged disabled persons. Steady state visual evoked potential (SSVEP) is one of non-invasive EEG signals, and it has been widely used in research in recent years. SSVEP is a kind of rhythmic brain activity simulated by continuous visual stimuli. SSVEP frequency is composed of a fixed visual stimulation frequency and its harmonic frequencies. The two-dimensional ensemble empirical mode decomposition (2D-EEMD) is an improved algorithm of the classical empirical mode decomposition (EMD) algorithm which extended the decomposition to two-dimensional direction. 2D-EEMD has been widely used in ocean hurricane, nuclear magnetic resonance imaging (MRI), Lena image and other related image processing fields. The present study shown in this paper initiatively applies 2D-EEMD to SSVEP. The decomposition, the 2-D picture of intrinsic mode function (IMF), can show the SSVEP frequency clearly. The SSVEP IMFs which had filtered noise and artifacts were mapped into the head picture to reflect the time changing trend of brain responding visual stimuli, and to reflect responding intension based on different brain regions. The results showed that the occipital region had the strongest response. Finally, this study used short-time Fourier transform (STFT) to detect SSVEP frequency of the 2D-EEMD reconstructed signal, and the accuracy rate increased by 16%.
ObjectiveTo reveal and demonstrate the hotspots and further research directions in screening technology for early lung cancer, and provide references for the future studies. MethodsResearches related to lung cancer screening from 2011 to 2021 in the Web of Science database were included. Biblioshiny, a bibliometrics program based on R language, was used to perform content analysis and visualization of the included literature information. ResultsResearches related to lung cancer screening were increasing year by year. Six major cooperation groups were formed between countries. The current research hotspots in the field of early lung cancer screening technology mainly focused on the multi-directional fusion of radiographic imaging, liquid biopsy and artificial intelligence. ConclusionLow-dose spiral CT screening is still the most important and mainstream method for the screening of early lung cancer at present. The combination and integration of artificial intelligence with various screening methods and the innovation of novel testing and diagnostic equipment are the current research hotspots and the future research trend in this field.
ObjectiveBased on the method of bibliometrics, to visually analyze the current research status of DNA polymerase epsilon catalytic/DNA polymerase delta catalytic subunit (POLE/POLD1) mutations in colorectal cancer, and further to explore its current hot spots and to look forward to future development trends.MethodsUsed the Web of Science database as the data source to retrieve the published related literatures in the 30 years from the establishment of the database to September 2020, and used VOSviewer 1.6.11 and CiteSpace 5.7 software to analyze the the distribution of research countries/institutions, authors and keywords in the included published literatures. And to perform cluster analysis, time evolution analysis and Burst analysis on keywords, draw corresponding visual maps and analyzed them.ResultsA total of 299 published articles were included. Bibliometric analysis showed that the application of POLE/POLD1 mutations in colorectal cancer had developed steadily in recent years. After 2012, the number of published studies had increased significantly; the journals with the most articles were Familial Cancer and Proceedings of the National Academy of Sciences of the United States of America. The author with the highest number of articles was Tomlinson I. The analysis of countries and regions showed that the United States was the main country for research in this field and had contributed the most to the amount of publications. After analyzed the academic institutions/universities where the researchers were located, it could be seen that the University of Oxford was the research university/institution with the most publications. Keyword cluster analysis and time evolution analysis showed that the research hotspots in this field focus on the impact of this gene mutation on immunotherapy. Burst analysis showed that the current published research in this field started two years after publication and continues to be highly cited.ConclusionsPOLE/POLD1 mutation has undoubtedly become a hot area of current research in colorectal cancer research. Among them, tumor immunotherapy is the focus of research in this field.
Objective To compare the effect of electrode positions on multifocal visual evoked potential(mf-VEP). Methods Ten healthy individuals were tested with RETIscan multifocal VEP system 3.20, each individual was tested with four electrode positions: the active and reference electrode were placed 2.0 cm above and below the inion in Ch1；3.0 cm above and 4.5 cm below the inion in Ch2；2.0 cm on both right and left side of the inion in Ch3 and 4.0 cm on both right and left side of the inion in Ch4. The summed amplitudes of hemifield mf-VEP were analyzed and compared according to different electrode positions. Results The difference among summed amplitudes of the upper or lower hemifield mf-VEP recorded with Ch1、Ch2、Ch3 and Ch4 was statistically significant；and the difference between Ch2 and the other channels was statistically significant too. The difference among summed amplitudes of the horizontal sites whose amplitudes were small when recorded with Ch2 and summed amplitudes of the corresponding sites recorded with Ch3 and Ch4 were statistically significant；and the difference between Ch4 and the other channels was statistically significant too. Conclusions compared to Ch1、Ch3 and Ch4, Ch2 can make a better recording of mf-VEP. As for some sites, especially those along horizontal line, horizontal electrodes could improve the amplitudes of mf-VEP recorded with vertical electrodes，and Ch4 could do better to improve the mf-VEP recorded with Ch2 than Ch3. (Chin J Ocul Fundus Dis，2004，20：346-348)
ObjectiveTo investigate the current status and hotspots in researches of gastrointestinal stromal tumor.MethodsThe literatures related to gastrointestinal stromal tumor and published from 2000 to 2019 were extracted from Web of Science Core Collection. Visualization analysis was conducted by utilizing CiteSpace and VOSviewer software based on bibliometrics methods.ResultsA total of 3 226 articles and reviews were retrieved. The number of publications increased from 2000 to 2019, from the initial 34 publications gradually increased to 241 in 2019, and the maximum number of publications was 265 in 2015. The most productive five countries in terms of publication number were: 907 in the United States, 540 in China, 522 in Japan, 219 in Germany, and 214 in Italy. Co-occurrence networks of keywords were divided into three clusters: targeted therapy, clinical management, and pathogenesis research. Co-citation analysis of literatures contained 9 clusters, and cluster #0 prognosis was the latest cluster, indicating the research frontier and tendency.ConclusionsThe United States and its domestic institutes are the pioneers. Targeted therapy, clinical management, and pathogenesis researches are the main research filed. Prognosis research may be the new research tendency, and clinical and basic researches are still hotspots in medical research.
Objective To explore the research hotspots and latest progress of lung transplantation nursing at home and abroad, and to provide reference ideas and directions for the future related research. Methods Through the collection of CNKI and Web of Science core database, the related literature of lung transplantation nursing from inception to December 2023 was retrieved and CiteSpace software was used to focus on keyword co-occurrence, clustering and emergence. Results A total of 352 Chinese literature and 126 English literature were included in this study, and the number of papers published at home and abroad showed an overall upward trend. There were 34 core authors of Chinese literature and 83 core authors of English literature. The core authors led the team to promote research and promote cooperation at home and abroad. At present, the cooperation among research teams needed to be strengthened. Chinese literature keywords included nursing, lung transplantation, extracorporeal membrane oxygenation, lung rehabilitation, lung transplantation surgery, complications. English literature keywords included lung transplanation, quality of life, international society, disease, bone marrow transplantation. There were 15 clusters and 25 emergent keywords in the CNKI database, and 12 clusters and 25 emergent keywords in the Web of Science core database. ConclusionThe study of lung transplantation nursing at home and abroad has been paid more and more attention, and the research is getting more and more sophisticated. The future study can realize the holistic care of patients during perioperative period on the basis of clinical diagnosis and nursing technology, and improve the survival of patients after operation.
In this study, loop-mediated isothermal amplification (LAMP) assay in conjunction with calcein for visualized detection of Mycobacterium tuberculosis (MTB) was established. Firstly, four LAMP primers were designed according to the region of 16S rDNA sequences of MTB. Secondly, clinical sputum samples were collected, decontaminated and their DNA was extracted. Thirdly, standard MTB strains were used to evaluate the specificity and sensitivity of LAMP. At the same time, electrophoresis was used for products detection and calcein was used for visualized verification. At last, Chi-squared test function in SPSS 17.0 software was used for consistency evaluation of LAMP assay as compared with the gold standard (culture method). Results showed that there was no nonspecific amplification appeared in the specificity assay and the detection limit was 10 copies/tube in the sensitivity assay. In addition, visualized method by calcein had a comparable sensitivity with that of electrophoresis method. After evaluation of clinical practicability, the sensitivity of LAMP was calculated as 94.74% and the specificity was 90%, respectively. And Chi-squared test showed that LAMP and culture method had no statistic difference, and the two methods were in good consistency (P>0.05). In conclusion, LAMP assay introduced in our study has the characteristics of high efficiency and visualized detection so that this technique has great application prospects in the resource-limited environment, such as work field and primary care hospitals.
Objective To use visualization methods to illustrate and compare major subjects, domains, and developments in evidence-based medicine (EBM) in recent years. Methods We analyzed MeSH terms and keywords in EBM articles in the MEDLINE and CNKI databases, and developed subject charts, research field relationship charts, and strategy coordination charts using word co-occurrence, PFNET algorithms, and visualization methods. Results Rapid developments and growth are taking place in EBM in China and around the world. Studies on humans comprised 94.4% of the EBM studies that we identified, while animal studies accounted for 2.6% (three quarters of these animal studies were on primates). The six countries with the largest number of EBM articles and the eight host nations for the 108 journals with the most EBM publications were from high-income countries. In China, 31 provinces, municipalities, and autonomous regions have published EBM articles, although most of these publications come from the more highly-developed areas of the country. The investigation of word co-occurrence showed that EBM articles outside of China involve seven main fields: “Therapy”, “Methods”, “Standards”, “Research”, “Education”, ”Nursing” and “Organization and Administration”. Five of these fields (“Therapy”, “Nursing”, “Research”, “Education” and “Management”) were common to China but the top seven fields for this country included “Traditional Chinese Medicine (TCM)” and “Information resources”; and did not include “Methods” and “Standards”. Furthermore, studies on “Nursing” and “Research” were not as advanced in China as in other countries. Conclusion There are similarities between China and the rest of the world in several areas in the EBM literature but also some important differences. Throughout the world, the most resource-rich regions or organizations tend to have the most well-developed EBM. These regions and organizations are producing more evidence and conducting more methodology research than the less resourced regions and organizations. There is an urgent need for these regions and organizations to strengthen their use of evidence, to learn more about the philosophy that underpins EBM, and to improve accessibility to, and use of, evidence in choices about health care.
