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find Keyword "frequency" 192 results
  • Design and implementation for portable ultrasound-aided breast cancer screening system

    Early screening is an important means to reduce breast cancer mortality. In order to solve the problem of low breast cancer screening rates caused by limited medical resources in remote and impoverished areas, this paper designs a breast cancer screening system aided with portable ultrasound Clarius. The system automatically segments the tumor area of the B-ultrasound image on the mobile terminal and uses the ultrasound radio frequency data on the cloud server to automatically classify the benign and malignant tumors. Experimental results in this study show that the accuracy of breast tumor segmentation reaches 98%, and the accuracy of benign and malignant classification reaches 82%, and the system is accurate and reliable. The system is easy to set up and operate, which is convenient for patients in remote and poor areas to carry out early breast cancer screening. It is beneficial to objectively diagnose disease, and it is the first time for the domestic breast cancer auxiliary screening system on the mobile terminal.

    Release date:2022-06-28 04:35 Export PDF Favorites Scan
  • Association between genetic polymorphisms of vascular endothelial growth factor and the prognosis of retinopathy of prematurity

    Objective To determine the association between the geneti c polymorp hisms of vascular endothelial growth factor (VEGF) gene and the prognosis for retinopathy of prematurity (ROP) in Chinese. Methods Twenty infants with threshold ROP who had undergone retinal photocoagulation were in the treated group and 20 infants with self-regressed ROP without any treatment were in the control grou p . In the two groups, all the infants had oxygen-breathing history and the sex a n d gestational age were all suitable to be compared, except birth weight. Polymer ase chains reaction-restriction fragment length polymorphism was used to determine the frequencies of VEGF genes in the two groups. Results The frequencies of +405C allele were higher in the treated group than those in the control group (P<0.05). The frequencies of the VEGF-460T/C and +936C/T ploymorphisms were similar in both groups (P>0.05). Conclusions The +4 05C/G ge netic polymorphisms of VEGF may correlate to the prognosis of ROP. The carriers of +405CC allele are more susceptible to ROP.

    Release date:2016-09-02 05:46 Export PDF Favorites Scan
  • Systemic inflammatory response syndrome after radiofrequency ablation of hepatic hemangioma

    Radiofrequency ablation for hepatic hemangioma is safe and effective, and can obtain the same curative effect as traditional surgical resection. For hepatic hemangiomas with large volume, abundant arterial blood supply and long ablation time, systemic inflammatory response syndrome (SIRS) often occurs after radiofrequency ablation, which can lead to injury or dysfunction of important organs. This paper systematically summarizes the mechanism, prevention and treatment of SIRS after radiofrequency ablation of hepatic hemangioma, so as to provide reference for improving the safety of radiofrequency ablation of hepatic hemangioma.

    Release date:2022-10-09 02:05 Export PDF Favorites Scan
  • Effect of High Intensity Focused Ultrasound on Immunity of Patients with Advanced Primary Liver Cancer

    【Abstract】ObjectiveTo investigate the effect of high intensity focused ultrasound (HIFU) on the immunity of patients with advanced primary liver cancer (PLC). MethodsForty cases of PLC admitted to our institution from Mar. 2003 to Dec. 2003 were included in this study. Patients were divided into 2 groups and received either HIFU or radiofrequency ablation (RFA) treatment randomly. CD3, CD4, CD8, CD4/CD8, NK, IL-2, TNF were chosen to assess the immune status before and after treatment. The results were compared statistically. ResultsThe survival rate after HIFU was 80.0%, 61.1%, 42.9%, 33.3% at 3 months, 6 months, 9 months and 1 year respectively, which was similar to that after RFA treatment. The changes of immunity parameters of CD3, CD4, CD8, CD4/CD8, NK, IL-2 and TNF were not significant after HIFU treatment. In addition, the differences of those parameters between HIFU group and RFA group were insignificant. ConclusionThere are no detrimental effects on immunity in the early period after HIFU treatment.

    Release date:2016-09-08 11:52 Export PDF Favorites Scan
  • Comparison of different surgical treatments for early-stage gallbladder cancer

    Objective To compare the clinical efficacy and safety of different surgical methods in the treatment of early-stage gallbladder carcinoma (GBC). Methods The clinical data of 43 patients with early-stage GBC who received treatment in Peking University People’s Hospital from Jan. 2010 to Dec. 2016 were retrospectively analyzed. According to the surgical methods, the patients were divided into laparoscopic cholecystectomy (LC)+lymph node dissection (LND)+radiofrequency ablation (RA) group, open cholecystectomy (OC)+LND+RA group, and OC+LND+liver resection (LA) group. Operation duration, intraoperative blood loss, postoperative hospital stay, surgical complications, and long-term survival were compared among the 3 groups. Results All the 43 patients performed successful surgery without perioperative death. ① Operation duration and postoperative hospital stay. The differences of operation duration and postoperative hospital stay among the 3 groups were statistically significant (P<0.05). Compared with the LC+LND+RA group, operation duration and postoperative hospital stay of the OC+LND+RA group and the OC+LND+LR group were longer (P<0.017), but there was no statistically significant difference between the OC+LND+RA group and the OC+LND+LR group (P>0.017). ② Intraoperative blood loss. The difference of intraoperative blood loss among the 3 groups was statistically significant (P<0.001). Compared with the OC+LND+LR group, the intraoperative blood loss was lower in the LC+LND+RA group and the OC+LND+RA group (P<0.017), but there was no significant difference between the LC+LND+RA group and the OC+LND+RA group (P=0.172). ③ Postoperative complications. There was no significant difference in the incidence of postoperative complications among the 3 groups (P=0.326). ④ Long-term survival. There was no significant difference in survival curves among the 3 groups (P=0.057). Conclusions The method of cholecystectomy combined with LND and RA of gallbladder bed can achieve the radical effect on early-stage GBC (Tis–T2). Laparoscopic surgery, in particular, has shorter operation duration and faster recovery.

    Release date:2017-10-17 01:39 Export PDF Favorites Scan
  • High-frequency ultrasounic observation of localization and operation accuracy of traditional blind acupotomy lysis in treatment of scapulohumeral periarthritis

    ObjectiveTo observe the accuracy of location and operation of traditional blind acupotomy lysis in the treatment of scapulohumeral periarthritis by using the high-frequency ultrasound.MethodsForty-two patients with scapulohumeral periarthritis diagnosed in the First Affiliated Hospital of Xinjiang Medical University and Urumqi Hospital of Traditional Chinese Medicine from February to April 2018 were selected. Four common sites of needle knife in the treatment of scapulohumeral periarthritis were operated blindly, and the process of the needle insertion points location and needle perform were both observed by high-frequency ultrasound.ResultsUsing high-frequency ultrasound to observe and confirm the bare-handed positioning point and needle-knife operating point, we found that the accuracy rate of bare-handed positioning needle-point was 100.0% (42/42). In the process of needling, the accuracies of needle insertion at the point of small tubercle of humerus and the point of bursa of deltoid muscle were high, which was 95.2% (40/42) and 100.0% (42/42), respectively. However, because of the deviation of the needle depth and direction, the accuracies of needle insertion at the coracoid point and the sulcus point between the humeral tubercles were low, which was 45.2% (19/42) and 4.8% (2/42), respectively.ConclusionsTraditional acupotomy lysis is a commonly used method of needle knife treatment. Using high-frequency ultrasound, it is found that even by experienced needle knife doctors, there may still be positioning deviation when using blind method to insert needles. Because the visualization of clinical needle knife is difficult to be carried out universally due to the limitations of time and technology, it is suggested that high-frequency ultrasound could be used as a visualization teaching tool in the training of needle knife operation to assist the training of blind needle knife operation technology, which may improve the accuracy of blind needle knife operation.

    Release date:2018-10-22 04:14 Export PDF Favorites Scan
  • Pulmonary Vein Stenosis after Radiofrequency Ablation for Atrial Fibrillation: Two Cases Report and Literature Review

    ObjectiveTo analyze the clinical presentations and radiological characteristics of pulmonary vein stenosis after radiofrequency ablation. MethodsClinical and radiological data of 2 patients with pulmonary vein stenosis after radiofrequency ablation for atrial fibrillation were retrospectively analyzed and literatures were reviewed. ResultsBoth patients had undergone circumferential pulmonary vein isolation. The symptoms appeared approximately 2 months after the operation. The major symptoms were cough, hemoptysis, exacerbation of dyspnea and chest pain. Both patients were misdiagnosed as other diseases such as pneumonia in other hospitals, and the anti-infection therapy was invalid. Both CT scans showed parenchymal exudative consolidation with varying degrees of interstitial septal thickening and small nodules. Both patients were confirmed as pulmonary vein stenosis by CT angiography. Literature review identified 21 cases of pulmonary vein stenosis after radiofrequency ablation for atrial fibrillation. The main clinical features are hemoptysis, chest pain, shortness of breath and cough. The most common features of thoracic radiological imaging are consolidation, groud-glass attenuation, pleural effusion and interstitial septal thickening. ConclusionsIf a patient presents with hemoptysis, dyspnea, chest pain or other clinical manifestations after ablation therapy and image findings show parenchymal exudative consolidation with interstitial septal thickening and multiple small nodules, the possibility of pulmonary vein stenosis should be considered. Contrast-enhanced CT combined with pulmonary vein imaging technology can clearly show the opening diameter of each pulmonary vein and its branches, so it is an important non-invasive examination method for the evaluation and diagnosis of pulmonary vein stenosis.

    Release date:2016-10-10 10:33 Export PDF Favorites Scan
  • Sonography of Male Breast Lesions and the Pathological Diagnosis:A Retrospective Study of 10 Years and Literature Review

    The sonographic features of male breast lesions, which underwent ultrasound examination in our hospital for the past 10 years, were retrospectively analyzed. Sonographic features of these lesions were standardized as BI-RADS image lexicon. The differences in ultrasonic malignant signs were assessed between the benign and the malignant diseases. Between the two groups, incomplete boundary was statistically different. The specificity was above 95% within the two groups in terms of speculated margin, echogenic halo, calcification, axillary lymphadenopathy, thickening of skin and eccentric of mass to the nipple. High-frequency sonographic examination has a high level of differential diagnosis for male breast lesions.

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  • Recognition of high-frequency steady-state visual evoked potential for brain-computer interface

    Coding with high-frequency stimuli could alleviate the visual fatigue of users generated by the brain-computer interface (BCI) based on steady-state visual evoked potential (SSVEP). It would improve the comfort and safety of the system and has promising applications. However, most of the current advanced SSVEP decoding algorithms were compared and verified on low-frequency SSVEP datasets, and their recognition performance on high-frequency SSVEPs was still unknown. To address the aforementioned issue, electroencephalogram (EEG) data from 20 subjects were collected utilizing a high-frequency SSVEP paradigm. Then, the state-of-the-art SSVEP algorithms were compared, including 2 canonical correlation analysis algorithms, 3 task-related component analysis algorithms, and 1 task discriminant component analysis algorithm. The results indicated that they all could effectively decode high-frequency SSVEPs. Besides, there were differences in the classification performance and algorithms' speed under different conditions. This paper provides a basis for the selection of algorithms for high-frequency SSVEP-BCI, demonstrating its potential utility in developing user-friendly BCI.

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  • Study of Resonant Frequency in Diagnosing of Low Frequency Conductive Hearing Loss

    Objective To investigate the relationship of resonant frequency and low frequency conductive hearing loss. Methods Eighty- four participants were included, and tested by gold standard and resonant frequency respectively. Receiver operator characteristic (ROC) curve was used to explore the most appropriate cutoff point for diagnosing low frequency conductive hearing loss and Levene’s test was used to test the difference of the low frequency conductive hearing loss and normal hearing groups. Results The resonant frequencies of low conductive frequency hearing loss and normal hearing groups were different. The optimum cutoff points of resonant frequency were 850Hz and 1 050Hz. The resonant frequency range from 850Hz to 1 050Hz was considered normal. The test was powerful when the resonant frequency was lower than 850Hz. The test was powerless when the resonant frequency was higher than 1 050Hz. Conclusions Conductive hearing loss could be predicted from resonant frequency when it is lower than 850Hz. The test is powerless when the resonant frequency is higher than 1 050Hz. The resonant frequency could be affected by many factors, so ENT (ear, nose and throat) doctors and audiologists have to be careful about how to explain the results when the resonant frequency is higher than 1 050Hz.

    Release date:2016-09-07 02:25 Export PDF Favorites Scan
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