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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
  • 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
  • Estimation of the number of patients with mitral regurgitation in China

    Mitral regurgitation (MR) is the most common heart valve disease. In recent years, the rise of interventional therapy has expanded the indications of interventional treatment for patients with MR, but the epidemiological characteristics of MR (especially the number of patients with MR requiring treatment) in China are still unclear. In this paper, we analyzed and estimated the number of MR patients in China based on three epidemiological studies in Europe and America, and referring to the patients population surveys from Zhongshan Hospital Affiliated to Fudan University, the Second Affiliated Hospital Zhejiang University School of Medicine and Beijing Fuwai Hospital. Our analysis estimated that about 7.5 million patients with MR need intervention in China, including about 5.5 million patients with severe MR.

    Release date:2021-06-07 02:03 Export PDF Favorites Scan
  • APPLICATION OF ISOIONIC MICROTRAUMA ARTHROSCOPE ON TREATMENT OF KNEE ARTHROPATHY

    Objective To investigate the clinical applicationand curative effect of isoionic microtrauma arthroscope on treatment of knee arthropathy. Methods From May 2003 to November 2004, 52 cases of knee joint injury were cured by using isoionic microtrauma arthroscope, including 30 cases ofknee osteoarthritis, 10 cases of meniscus injury, 5 cases of kneecap dislocation, 5 cases of laxity of anterior cruciate ligation and 2 cases of rheumatoid arthritis. In accordance with Lysholm criterion for knee joint function, the scores were 35.5±4.9 before operation. Results All of these patients were followed up for 2-17 months. The scores of knee joint function was 86.4±5.3 after operation, and there was significant difference (Plt;0.001). Conclusion Isoionic microtrauma arthroscope is characterized by low-temperature hemoagglutination, crimpling,boiling, cutting and hemostasia, which makes kneejoint arthroscope operation easier-to-do, miner histological scathe and lighter side effect; so it is favourable for functional recovery and its curative effect is satisfactory.

    Release date:2016-09-01 09:30 Export PDF Favorites Scan
  • A study on the application of cross-frequency coupling characteristics of neural oscillation in the diagnosis of mild cognitive impairment

    In order to fully explore the neural oscillatory coupling characteristics of patients with mild cognitive impairment (MCI), this paper analyzed and compared the strength of the coupling characteristics for 28 MCI patients and 21 normal subjects under six different-frequency combinations. The results showed that the difference in the global phase synchronization index of cross-frequency coupling under δ-θ rhythm combination was statistically significant in the MCI group compared with the normal control group (P = 0.025, d = 0.398). To further validate this coupling feature, this paper proposed an optimized convolutional neural network model that incorporated a time-frequency data enhancement module and batch normalization layers to prevent overfitting while enhancing the robustness of the model. Based on this optimized model, with the phase locking value matrix of δ-θ rhythm combination as the single input feature, the diagnostic accuracy of MCI patients was (95.49 ± 4.15)%, sensitivity and specificity were (93.71 ± 7.21)% and (97.50 ± 5.34)%, respectively. The results showed that the characteristics of the phase locking value matrix under the combination of δ-θ rhythms can adequately reflect the cognitive status of MCI patients, which is helpful to assist the diagnosis of MCI.

    Release date:2023-10-20 04:48 Export PDF Favorites Scan
  • Diagnosis of pulmonary hypertension associated with congenital heart disease based on statistical features of the second heart sound

    Aiming at the problems of obscure clinical auscultation features of pulmonary hypertension associated with congenital heart disease and the complexity of existing machine-aided diagnostic algorithms, an algorithm based on the statistical characteristics of the high-frequency components of the second heart sound signal is proposed. Firstly, an endpoint detection adaptive segmentation method is employed to extract the second heart sounds. Subsequently, the high-frequency component of the heart sound is decomposed using the discrete wavelet transform. Statistical features including the Hurst exponent, Lempel-Ziv information and sample entropy are extracted from this component. Finally, the extracted features are utilized to train an extreme gradient boosting algorithm (XGBoost) classifier, which achieves an accuracy of 80.45% in triple classification. Notably, this method eliminates the need for a noise reduction algorithm, allows for swift feature extraction, and achieves effective multi-classification using only three features. It is promising for early screening of pulmonary hypertension associated with congenital heart disease.

    Release date:2024-04-24 09:40 Export PDF Favorites Scan
  • A prospective study of super-thin anterolateral thigh flap harvesting assisted by high-frequency color Doppler ultrasound in detecting perforators in deep adipose layers

    Objective To investigate the clinical application of high-frequency color Doppler ultrasound (HFCDU) in detecting perforators in the deep adipose layers for harvesting super-thin anterolateral thigh flap (ALTF). Methods Between August 2019 and January 2023, 45 patients (46 sides) with skin and soft tissue defects in the foot and ankle were treated, including 29 males and 16 females, aged from 22 to 62 years, with an average of 46.7 years. The body mass index ranged from 19.6 to 36.2 kg/m2, with an average of 23.62 kg/m2. The causes of injury included traffic accident injury in 15 cases, heavy object crush injury in 20 cases, mechanical injury in 8 cases, heat crush injury in 1 case, and chronic infection in 1 case. There were 20 cases on the left side, 24 cases on the right side, and 1 case on both sides. After thorough debridement, the wound size ranged from 5 cm×4 cm to 17 cm×11 cm. All patients underwent free super-thin ALTF transplantation repair. HFCDU was used to detect the location of the perforators piercing the deep and superficial fascia, as well as the direction and branches of the perforators within the deep adipose layers before operation. According to the preoperative HFCDU findings, the dimensions of the super-thin ALTF ranged from 6 cm×4 cm to 18 cm×12 cm. The donor sites of the flaps were directly sutured. Results A total of 55 perforators were detected by HFCDU before operation, but 1 was not found during operation. During operation, a total of 56 perforators were found, and 2 perforators were not detected by HFCDU. The positive predictive value of HFCDU for identifying perforator vessels was 98.2%, and the sensitivity was 96.4%. Among the 54 perforators accurately located by HFCDU, the orientation of the perforators in the deep adipose layers was confirmed during operation. There were 21 perforators (38.9%) traveled laterally and inferiorly, 12 (22.2%) traveled medially and inferiorly, 14 (25.9%) traveled laterally and superiorly, 5 (9.3%) traveled medially and superiorly, and 2 (3.7%) ran almost vertically to the body surface. Among the 54 perforators accurately located by HFCDU, 35 were identified as type 1 perforators and 12 as type 2 perforators (HFCDU misidentified 7 type 2 perforators as type 1 perforators). The sensitivity of HFCDU in identifying type 1 perforators was 100%, with a positive predictive value of 83.3%. For type 2 perforators, the sensitivity was 63.2%, and the positive predictive value was 100%. The surgeries were successfully completed. The super-thin ALTF had a thickness ranging from 2 to 6 mm, with an average of 3.56 mm. All super-thin ALTF survived, however, 1 flap experienced a venous crisis at 1 day after operation, but it survived after emergency exploration and re-anastomosis of the veins; 1 flap developed venous crisis at 3 days after operation but survived after bleeding with several small incisions; 3 flaps had necrosis at the distal edge of the epidermis, which healed after undergoing dressing changes. All 45 patients were followed up 6-18 months (mean, 13.6 months). Three flaps required secondary defatting procedures, while the rest had the appropriate thickness, and the overall appearance was satisfactory. Conclusion Preoperative application of HFCDU to detect the perforator in the deep adipose layers can improve the success and safety of the procedure by facilitating the harvest of super-thin ALTF.

    Release date:2024-01-12 10:19 Export PDF Favorites Scan
  • Feasibility of radiofrequency ablation of great saphenous varicose veins in day surgery

    ObjectiveTo explore the feasibility of radiofrequency ablation of great saphenous varicose veins in ambulatory surgery.MethodsPatients who underwent radiofrequency ablation of great saphenous varicose veins between May 2018 and June 2019 in General Hospital of Northen Theater Command were prospectively selected. According to their choices of treatment modes, patients were divided into two groups, day surgery group and routine inpatient group. The preoperative waiting time, length of hospital stay, and hospitalization expenses of the two groups were compared. The postoperative pain, tenderness, and complications were followed up on the first day (the next day after operation), the third day, and the fourteenth day after operation, and the time of return to normal life and work and patients’ satisfaction in two groups were recorded.ResultsA total of 95 patients were enrolled, including 52 in the day surgery group and 43 in the routine inpatient group. There was no significantly difference in age, gender, heart rate, mean arterial pressure, or operation time between the two groups (P>0.05). Compared with the routine inpatient group, the day surgery group had shorter preoperative waiting time, shorter length of hospital stay, and lower hospitalization expenses (P<0.05). In the day surgery group, the time of return to normal life and the time of return to work were shorter and patients’ satisfaction was significantly higher than those in the routine inpatient group (P<0.05). There was no significant difference in pain, tenderness, or paresthesia scores between the two groups after surgery according to the follow-up assessment (P>0.05); the pain, tenderness, and paresthesia scores on the first day and the third day were significantly different from those on the fourteenth day after surgery, indicating that the longer the postoperative time of the two groups, the less pain, tenderness, and paresthesia scores were.ConclusionRadiofrequency ablation of great saphenous varicose veins in ambulatory surgery has a short hospital stay, low medical cost, high patient satisfaction, and can ensure the safety of treatment at the same time, which is worthy of clinical promotion

    Release date:2021-03-19 01:22 Export PDF Favorites Scan
  • Gravity Frequency and Its Monitoring Application of EEG Spectrum in the Vigilance Operation

    It is an important means to study the electrical activity of the brain's nerve cells by exploring physiological information of the EEGs from the frequency domain. The gravity frequency is one of the global parameters with using this method. We used the multitaper spectrum method (MTM) spectrum estimation method of good performance to calculate the EEG spectrum and its gravity frequency of subjects under vigilance and vigilance decrement state. The results showed that the gravity frequency of vigilance state was higher than that of vigilance decrement state, the gravity frequency became smaller along with the vigilance decrement, and the location of the gravity frequency shifted to the left in the spectrum. Finally, the monitoring curve of the gravity frequency was acquired by designing an algorithm, and it was used to online monitoring vigilance operators.

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