Objective To explore the change of EEG waveform recorded by clinical EEG under different filtering parameters. Methods22 abnormal EEG samples of epilepsy patients with abundant abnormal waveforms recorded in Peking University first hospital were selected as the case group (abnormal group), and 30 normal EEG samples of healthy people with matched sex and age were selected as the control group (normal group). Visual examination and power spectrum analysis were then performed to compare the difference of wave forms and spectrum power under different settings of filter parameter between the two groups. ResultsThe results of visual examination show that, lower high-frequency filtering has an effect on the fast wave composition of EEG and may distort and reduce the spike wave. Higher low-frequency filtering has an effect on the overall background and slow wave activity of EEG and may change the amplitude morphology of some slow waves. The results of power spectrum analysis show that, Compare the difference between the EEG normal group and the abnormal group, the main difference under the settings of 0.5~70Hz was on the θ and α3 frequency band, different brain regions were slightly different. In the central region, the difference in the high frequency band (α3, γ1, γ2) decreases or disappears with the decrease of the high frequency filtering. In the rest of the brain, the difference in the δ band appears gradually with the increase of the low frequency filtering. Compare the difference between frontal area and occipital area under different filter set, for the normal group, under the settings of 0.5 ~ 70 Hz, the difference between two regions is mainly on the θ, γ1 and γ2 band. When high frequency filter reduces, the difference between two regions on high frequency band (γ1, γ2) are gradually reduced or disappeared. And when low frequency filter increases, the difference on δ band appears. For the abnormal group, the difference between frontal and occipital region under the settings of 0.5 ~ 70 Hz is mainly on γ1 and γ2 bands. When the high-frequency filter decreases, the difference between two regions on high-frequency bands are gradually decreased or disappeared. All the results can be corrected by FDR. ConclusionThe results show that the filter setting has a significant influence on EEG results. In clinical application, we should strictly set 0.5 ~ 70 Hz bandpass filtering as the standard.
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.
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.
ObjectiveTo explore the clinical application of the comprehensive guidance technologies, such as cone beam computed tomography (CBCT), virtual bronchoscopic navigation (VBN), and superimposed high-frequency jet ventilator for respiratory control in the biopsy of peripheral pulmonary nodules (PPNs). MethodsThe clinical information of 3 patients with PPNs diagnosed by CBCT combined with VBN and superimposed high frequency superposition jet ventilator in Shanghai Changhai Hospital were retrospectively analyzed. Results Clinical data of 3 patients were collected. The average diameter of PPNs was (25.3±0.3) mm with various locations in left and right lung. The first nodule was located in the apex of the left upper lung, and the biopsy was benign without malignant cells. The lesion was not enlarged during the 5-year follow-up. The second one was located in the left lingual lung, and the postoperative pathology was confirmed as mucosa-associated lymphoma. The third one was located in the anterior segment of the right upper lung. After the failure of endobronchial procedure, percutaneous PPNs biopsy under CBCT combined with VBN was performed, and the pathological diagnosis was confirmed as primary lung adenocarcinoma. Postoperative pneumothorax complication occurred in the third patient with right lung compression rate approximately 20%. ConclusionsThe application of CBCT, combined with VBN and the superimposed high frequency jet ventilator for respiratory control can potentially improve the accuracy and safety in the diagnosis of PPNs. Multi-center clinical trials are needed to verify its further clinical application.
ObjectiveTo compare the advantages and drawbacks of harmonic scalpel (HS) versus conventional electro-scalpel (ES) in the surgery for carcinoma of uterine cervix. MethodsA total of 126 patients with stage Ⅰ uterine cervix carcinoma who underwent surgery between January 2011 and November 2015 were randomly and averagely divided into HS group and ES group with 63 patients in each. The operation time, intra-operative bleeding volume, the number of lymph nodes detected and operation cost were compared between the two groups of patients. ResultsAll the patients underwent surgery successfully. There were significant differences between the HS and ES groups in terms of operation time[(202.06±11.67) minutes vs.(223.48±18.01) minutes, P<0.001], intra-operative bleeding[(373.97±27.95) mL vs.(458.16±33.18) mL, P<0.001], operation cost[(4 171.43±276.46) yuan vs.(3 101.54±258.59) yuan, P<0.001]. There was no significant difference between the two groups in terms of the number of lymph nodes detected (10.38±2.43 vs.9.76±2.61, P=0.172). ConclusionThe use of harmonic scalpel can reduce operation time and intra-operative bleeding volume effectively, but it cannot increase the number of lymph nodes detected. Moreover, it significantly increases the operation cost and economic burden for the patients.