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find Keyword "spectrum" 49 results
  • An electroencephalogram-based study of resting-state spectrogram and attention in tinnitus patients

    The incidence of tinnitus is very high, which can affect the patient’s attention, emotion and sleep, and even cause serious psychological distress and suicidal tendency. Currently, there is no uniform and objective method for tinnitus detection and therapy, and the mechanism of tinnitus is still unclear. In this study, we first collected the resting state electroencephalogram (EEG) data of tinnitus patients and healthy subjects. Then the power spectrum topology diagrams were compared of in the band of δ (0.5–3 Hz), θ (4–7 Hz), α (8–13 Hz), β (14–30 Hz) and γ (31–50 Hz) to explore the central mechanism of tinnitus. A total of 16 tinnitus patients and 16 healthy subjects were recruited to participate in the experiment. The results of resting state EEG experiments found that the spectrum power value of tinnitus patients was higher than that of healthy subjects in all concerned frequency bands. The t-test results showed that the significant difference areas were mainly concentrated in the right temporal lobe of the θ and α band, and the temporal lobe, parietal lobe and forehead area of the β and γ band. In addition, we designed an attention-related task experiment to further study the relationship between tinnitus and attention. The results showed that the classification accuracy of tinnitus patients was significantly lower than that of healthy subjects, and the highest classification accuracies were 80.21% and 88.75%, respectively. The experimental results indicate that tinnitus may cause the decrease of patients’ attention.

    Release date:2021-08-16 04:59 Export PDF Favorites Scan
  • Number Variation Trend of Inpatients with Traumatic Brain Injury in High Altitude and Plain Areas

    Objective To explore the number variation trend of inpatients with traumatic brain injury (TBI) in high altitude and plain areas. Methods The first page information in medical records of TBI patients, who were admitted to military hospitals from 2001 to 2007, was searched and extracted from the Chinese Trauma Database. Two military hospitals in high altitude area and another two in the same hospital level in plain area were selected. Then, the number variation trend of TBI inpatients in those two areas was compared. Results In high altitude area, the proportion of male patients and their median inpatient days were higher, while the age, proportion of Han patients and surgery rate were lower than those in plain area (all Plt;0.001). During 2001-2007, there were 9 141 TBI patients discharged from the four hospitals, and the average annual growth rate was 13.15%. In high altitude area, the average annual growth rate of discharged inpatients was 24.00%, while in plain area, it was just 7.09%. The 4 common categories of TBI were intracranial injury, open wound of the head, neck and trunk, skull fracture, and other injuries. Conclusion Compared with the plain area, there are significant differences in the demographics, hospital stay and surgery of inpatients in high altitude area. The average annual growth rate of TBI inpatients discharged from hospitals in high altitude area is faster than that in plain area, to which should be paid attention by relevant departments.

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  • INFLUENCE OF IMMERSED TIME BY HYDROGEN DIOXIDE ON XENOGENEIC BONE SUBSTITUTE

    Objective To study the influence of the immersed time by hydrogen dioxide on the characteristics of bovine cancellous bone granules in various periods. Methods Ten 24-month-old Qinchuan bovine, male or female, weighing 150-170 g, were selected. Cancellous bone granules from metaphysic of bovine long bone were cut into cubes of 5 mm × 5 mm ×5 mm and immersed by 8.8 mol/L hydrogen dioxide for 0, 12, 24, 36, 48, 60 and 72 hours separately. Determination of ash, scanning electron microscope, X-ray energy spectrum and micro CT were used to investigate the changes of composition, structure and qual ity of bone. Results With the immersed time increasing, the contents of organics in the bone cancellous were reduced gradually, and obviously decreased during the periods of 0 to 24 hours and 60 to 72 hours (P lt; 0.05). The contents of calcium and phosphorus decreased gradually, they could not be detected almost after 60 days (P lt; 0.05). Bone mineral density and bone mineral content were decreased obviously after 60 hours (P lt; 0.05). The bone trabecula became sl immer and trabecular spacing became larger. Conclusion Hydrogen dioxide can be used to remove the antigen in xenogeneic bone; however as the time increasing (more than 60 hours) the composition and structure will be damaged. Thus it is important to control the immersed time for maintaining the biological characteristics of xenogeneic bone substitute as well as el iminating antigen by hydrogen dioxide.

    Release date:2016-09-01 09:06 Export PDF Favorites Scan
  • A study on the effects of transcranial direct current stimulation combined with motor imagery on brain function based on electroencephalogram and near infrared spectrum

    Motor imagery is often used in the fields of sports training and neurorehabilitation for its advantages of being highly targeted, easy to learn, and requiring no special equipment, and has become a major research paradigm in cognitive neuroscience. Transcranial direct current stimulation (tDCS), an emerging neuromodulation technique, modulates cortical excitability, which in turn affects functions such as locomotion. However, it is unclear whether tDCS has a positive effect on motor imagery task states. In this paper, 16 young healthy subjects were included, and the electroencephalogram (EEG) signals and near-infrared spectrum (NIRS) signals of the subjects were collected when they were performing motor imagery tasks before and after receiving tDCS, and the changes in multiscale sample entropy (MSE) and haemoglobin concentration were calculated and analyzed during the different tasks. The results found that MSE of task-related brain regions increased, oxygenated haemoglobin concentration increased, and total haemoglobin concentration rose after tDCS stimulation, indicating that tDCS increased the activation of task-related brain regions and had a positive effect on motor imagery. This study may provide some reference value for the clinical study of tDCS combined with motor imagery.

    Release date:2024-06-21 05:13 Export PDF Favorites Scan
  • Research Progress of Electrical Impedance Spectrum Technology in The Diagnosis of Thyroid Carcinoma

    Objective To summarize the basic principle of electrical impedance spectrum technology and the latest progress in the diagnosis of thyroid carcinoma. Methods By the domestic and overseas literatures review, medical application and diagnostic prospect in thyroid carcinoma of electrical impedance spectrum were summarized. Results Electrical impedance spectrum was a kind of somatic function imaging, whose measurement results was objective, and it could diagnose thyroid carcinoma in early stage effectively. In addition, it could be used as a complementary form of fine needle aspiration biopsy, improving the diagnostic accuracy rate of thyroid carcinoma, thereby reducing the unessential thyroid operations. Conclusion Electrical impedance spectrum technology is a potentially useful imaging modality for diagnosing thyroid carcinoma in early stage, and functions as a auxiliary clinical diagnosis method for fine needle aspiration biopsy.

    Release date:2016-09-08 10:35 Export PDF Favorites Scan
  • The Analysis of the Cause for Prehospital “120”Emergency Medical Services Cases Death

    摘要:目的: 探讨基层医院急诊“120”院前救治水平的影响。 方法 :分析301例死因,年龄及百分比。 结果 :急诊致死原因疾病病谱前9位分别是交通事故,猝死,溺水,意外伤害,自杀,电击伤,刀伤,一氧化碳中毒及呼吸道梗塞,“无名氏”群体86例占285%,这部分给临床和社会带来了新问题,这仍有待今后继续探讨。 结论 :完善基层医院“120”体系,提高救治水平。Abstract: Objective: To explore the factors relate to prehospital“120”Emergency Medical Services cases death. Methods : Analysis the cause for death, ages and percentage of the age in 301 cases. Results : Traffic accident, sudden death, drowns, accident, suicide, electric burn, knife trauma, anthracemia and respiratory tract obstruction were the leading cases in the diseases spectrum of the cause for death in emergency cases. 86 cases were anonym, which brought new problems to clinic treatment and provoked social issue, accounting for 285% in total cases. These remain us to study henceforth. Conclusion : Consummate the “120” Emergency MedicalServices system in grassroots hospital and enhance the level of cure.

    Release date:2016-09-08 10:12 Export PDF Favorites Scan
  • Feature exaction and classification of autism spectrum disorder children related electroencephalographic signals based on entropy

    The early diagnosis of children with autism spectrum disorders (ASD) is essential. Electroencephalography (EEG) is one of most commonly used neuroimaging techniques as the most accessible and informative method. In this study, approximate entropy (ApEn), sample entropy (SaEn), permutation entropy (PeEn) and wavelet entropy (WaEn) were extracted from EEGs of ASD child and a control group, and Student's t-test was used to analyze between-group differences. Support vector machine (SVM) algorithm was utilized to build classification models for each entropy measure derived from different regions. Permutation test was applied in search for optimize subset of features, with which the SVM model achieved best performance. The results showed that the complexity of EEGs in children with autism was lower than that of the normal control group. Among all four entropies, WaEn got a better classification performance than others. Classification results vary in different regions, and the frontal lobe showed the best performance. After feature selection, six features were filtered out and the accuracy rate was increased to 84.55%, which can be convincing for assisting early diagnosis of autism.

    Release date:2019-04-15 05:31 Export PDF Favorites Scan
  • Prediction of seizures in sleep based on power spectrum

    Seizures during sleep increase the probability of complication and sudden death. Effective prediction of seizures in sleep allows doctors and patients to take timely treatments to reduce the aforementioned probability. Most of the existing methods make use of electroencephalogram (EEG) to predict seizures, which are not specific developed for the sleep. However, EEG during sleep has its characteristics compared with EEG during other states. Therefore, in order to improve the sensitivity and reduce the false alarm rate, this paper utilized the characteristics of EEG to predict seizures during sleep. We firstly constructed the feature vector including the absolute power spectrum, the relative power spectrum and the power spectrum ratio in different frequencies. Secondly, the separation criterion and branch-and-bound method were applied to select features. Finally, support vector machine classifier were trained, which is then employed for online prediction. Compared with the existing method that do not consider the characteristics of sleeping EEG (sensitivity 91.67%, false alarm rate 9.19%), the proposed method was superior in terms of sensitivity (100%) and false alarm rate (2.11%). This method can improve the existing epilepsy prediction methods and has important clinical value.

    Release date:2018-08-23 03:47 Export PDF Favorites Scan
  • Study of Event related Brain Potential in Children with Attention Deficit Hyperactivity Disorder

    This study aims to explore the differences of event related potential (ERP) between attention deficit hyperactivity disorder (ADHD) and normal children, so that these differences provide scientific basis for the diagnosis of ADHD. Eight children were identified to be ADHD group by the diagnostic criteria of DSM IV (diagnostic and statistical manual of mental disorders IV), and the control group also consisted of 8 normal children. Modified visual continuous performance test (CPT) was used as the experiment paradigm. The experiment included two major conditions, i.e. Go and NoGo. All the 16 subjects participated in the study. A high density EEG acquisition instrument was used to record the EEG signal and processed these EEG data by means of ERP and spectrum analysis. P2 N2 peak peak value and spectral peak around 11 Hz were analyzed between ADHD subjects and those in the control group, and then statistical tests were applied to these two groups. Results showed that: ① Under the condition of Go, ADHD group had a significant lower P2 N2 peak peak value than the values in the control group ( P< 0.05); but under the condition of NoGo there was no significant difference in between. ② Compared with the control group, the ADHD group had significant lower spectral amplitude around 11 Hz under the condition of NoGo ( P< 0.05). However, under the condition of Go the difference was insignificant. In conclusion, there is certain cognitive dysfunction in ADHD children. P2-N2 peak-peak value and spectral peak around 11 Hz could be considered as clinical evaluation indexes of ADHD children′s cognitive function. These two objective indexes provide an early diagnosis and effective treatment of ADHD .

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  • Diagnostic accuracy of MRI in the diagnosis of preschool children with autism spectrum disorder: a meta-analysis

    ObjectiveTo systematically review the diagnostic accuracy of MRI in preschool children with autism spectrum disorder. MethodsDatabases including Web of Science, PubMed, The Cochrane Library, EMbase, CBM, CNKI, WanFang Data, and VIP were electronically searched for studies on MRI in diagnosis of preschool children with autism spectrum disorder from inception to January 2022. Two reviewers independently screened the literature, extracted data, and assessed the risk of bias the included studies. Then, meta-analysis was performed using Meta-Disc, RevMan 5.4 and Stata 16.0 software. ResultsA total of 17 studies were finally included. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnosis odds ratio and area under the curve of SROC were 0.78 (95%CI 0.76 to 0.81), 0.77 (95%CI 0.75 to 0.79), 3.92 (95%CI 2.83 to 5.41), 0.28 (95%CI 0.23 to 0.35), 14.8 (95%CI 9.31 to 23.52) and 0.86, respectively. Subgroup analysis revealed that the source of patients, age, prediction methods and analysis features were potential sources of heterogeneity. Heterogeneity in the subgroup of 1-3 years old was small, and the pooled sensitivity, specificity and area under the curve of SROC were 0.81 (95%CI 0.76 to 0.85), 0.82 (95%CI 0.78 to 0.86) and 0.87, respectively. The pooled sensitivity, specificity and area under the curve of SROC for non-site studies were 0.80 (95%CI 0.75 to 0.84), 0.80 (95%CI 0.76 to 0.85) and 0.86, respectively. ConclusionMRI has a high accuracy in the diagnosis of preschool children with autism spectrum disorder; however, the possibility of misdiagnosis and missed diagnosis should be considered. Due to the limited quantity and quality of the included studies, more high-quality studies are needed to verify the above conclusion.

    Release date:2022-04-28 09:46 Export PDF Favorites Scan
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