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        find Keyword "measurement" 59 results
        • Anthropometric measurements of moderate concha-type microtia after auricular cartilage unfolding

          ObjectiveTo explore the anthropometric changes of the auricle after auricular cartilage unfolding in moderate concha-type microtia patients, so as to provide the basis to help evaluate surgical timing and prognostic.MethodsA total of 33 children with moderate concha-type microtia, who were treated with auricular cartilage unfolding between October 2016 and September 2018 and met the inclusive criteria, were included in the study. There were 24 boys and 9 girls with an average age of 1.4 years (range, 1-3 years). Sixteen cases were left ears and 17 cases were right ears. The follow-up time was 12-23 months (mean, 17.5 months). The affected auricular detailed structures were observed and quantitatively analyzed before operation and at immediate after operation. The width, length, and perimeter of auricle before operation and at immediate after operation and at last follow-up were noted with three dimensional-scanning technology. The normal auricle was noted as control.ResultsThere were (7.5±1.0) and (11.3±0.8) structures of the affected auricle at pre- and post-operation, respectively, showing significant difference between pre- and post-operation (t=23.279, P=0.000). The length, width, and perimeter of the affected auricle constantly increased after operation, and there were significant differences between pre-operation and immediately after operation and between immediately after operation and last follow-up (P<0.05). The differences of length, width, and perimeter of the affected auricle between immediately after operation and last follow-up were (3.13±1.44), (2.44±0.92), and (8.50±3.76) mm, respectively. And the differences of length, width, and perimeter of the normal auricle between pre-operation and last follow-up were (3.16±1.54), (2.35±0.86), and (9.79±4.60) mm, respectively. There was no significant difference in the differences of length, width, and perimeter between the affected auricle and the normal auricle (P>0.05).ConclusionThe auricular cartilage unfolding in treatment of the moderate concha-type microtia can receive more ear structures and increase auricle sizes, which make it possible for free composite tissue transplantation. In addition, the affected and the contralateral normal auricles have a very similar growth rate and it offers the theoretical foundation for the early treatment for moderate concha-type microtia.

          Release date:2020-04-29 03:03 Export PDF Favorites Scan
        • Long-term dynamic change of liver elasticity in chronic hepatitis B virus infection

          ObjectiveAntiviral treatments could benefit chronic hepatitis B (CHB) patients with the regression or improvement of liver fibrosis. However, the degree of dynamic change of liver fibrosis for patients who had not received antiviral treatment remained to be studied. The current study aimed to observe the long-term variation of liver stiffness measurement (LSM), virological and biochemical response on patients without standard antiviral therapy.MethodsA total of 220 patients who were diagnosed with chronic HBV infection, who had not reached the standard of antiviral therapy, and completed a follow-up date of over 2 years in the First Affiliated Hospital of Xi’an Jiaotong University from 2012 to 2018 were retrospectively enrolled. According to the changes of LSM in baseline and follow-up period, the patients were divided into regression group, non-progressive group, and progressive group. The virological and biochemical characteristics of each group were analyzed.ResultsAmong the 220 patients, 153 patients (69.5%) had no progress in LSM degree. Alanine aminotransferase (ALT), HBV DNA, and HBsAg in a few patients increased or slightly decreased, while the vast majority remained in a relatively stable state. 89.5% (137/153) of the non-progressive patients were in grade F0. In addition, 58 patients showed spontaneous improvement with a decreasing rate of 0.460 kPa per year. Patients with ALT of 1-2 ULN had a statistically significant decrease in LSM improvement compared to patients with normal ALT. 82.8% of the LSM-improving patients showed baseline LSM of F1-F3. Only 9 patients showed LSM deterioration, however, which could not be explained by virus replication or necroinflammatory activity. ConclusionsFor patients unsatisfying standard antiviral therapy, most patients with baseline LSM of F0 grade fail to progress, and patients with baseline LSM of F1-F3 show a decrease during follow-up, LSM progression occurs in 4.1% of patients.

          Release date:2021-08-19 03:41 Export PDF Favorites Scan
        • Intraoperative Transit Time Flow Measurement during Sequential Coronary Artery Bypass Grafting

          Objective To investigate the use of intraoperative transit time flow measurement (TTFM) to accuratelyevaluate graft patency during sequential coronary artery bypass grafting (CABG). Methods Clinical data of 131 patientsundergoing sequential off-pump coronary artery bypass grafting (OPCAB) with the great saphenous vein (with or without internal mammary artery) as graft vessels in Beijing Anzhen Hospital from April 2012 to January 2013 were retrospectivelyanalyzed. There were 92 male and 39 female patients with their age of 61.35±8.24 years. During the operation,2 methods were used to measure mean blood flow volume,pulsatility index (PI) and diastolic filling (DF) of the graft vessels. For thenon-blocking method,blood flow in graft vessels was maintained,and TTFM was applied 2 cm proximal to the anastomoticsite in graft vessels to record above parameters. For the blocking method,blood flow in graft vessels was temporally blockedby clipping distal graft vessels with an atraumatic bulldog clamp,and TTFM was applied 2 cm proximal to the anastomotic site in graft vessels to record above parameters. Results Blood flow volumes of the diagonal branch (27.43±15.22 ml/minvs. 59.28±30.13 ml/min),obtuse marginal branch (26.14±19.74 ml/min vs. 47.19±24.27 ml/min) and posterior left ventr-icular branch (19.16±8.92 ml/min vs. 38.83±20.11 ml/min) measured by the blocking method were significantly smallerthan those measured by the non-blocking method (P<0.05) . PI values of the diagonal branch (2.93±1.30 vs. 2.31±0.91),obtuse marginal branch (2.62±1.17 vs. 2.01±0.87) and posterior left ventricular branch (2.33±0.92 vs. 1.80±0.73) meas-ured by the blocking method were significantly higher than those measured by the non-blocking method (P<0.05). There was no statistical difference in DF values measured by 2 methods at respective anastomotic sites,and all DF values were higher than 50%. Non-blocking method identified 1 anastomotic site and blocking method identified 3 anastomotic sites that were not patent,and these anastomotic sites became patent after graft reconstruction. Conclusion Blood flow velocity of sequential grafts is higher than that of single grafts,indicating that sequential grafts have the advantages of high blood flow volume and low risk of thrombosis. Blocking method can more accurately evaluate graft patency at the anastomotic sites and sensitively identify graft vessels that are not patent,which is helpful for anastomotic site reconstruction in time and enhancement of successful rate of CABG.

          Release date:2016-08-30 05:47 Export PDF Favorites Scan
        • ESTABLISHMENT OF A NEW RADIUS DEFECT MODEL BASED ON ULNA ANATOMICAL MEASUREMENT IN RABBITS

          ObjectiveTo introduce a new bone defect model based on the anatomical measurement of radius and ulna in rabbits for offering a standard model for further tissue engineering research. MethodsFifteen healthy 4-month-old New Zealand rabbits were selected for anatomic measurement and radiological measurement of the radius and ulna. Another 30 healthy 4-month-old New Zealand rabbits were randomly divided into groups A, B, and C (n=10). The radius bone defect was created bilaterally in 3 groups. In group A, the periosteum and interosseous membranes were fully removed with jig-saw by approach between extensor carpi radialis muscle and musculus extensor digitorum. The periosteum and interosseous membranes were fully removed in group B, and only periosteum was removed in group C with electric-saw by approach between extensor carpi radialis muscle and flexor digitorum profundus based on anatomical analysis results of ulnar and radial measurement. The gross observation, X-ray, micro-CT three-dimensional reconstruction, bone mineral density (BMD), and bone mineral content (BMC) were observed and recorded at immediate and 15 weeks after operation. HE staining and Masson staining were performed to observe bone formation in the defect areas. ResultsBlood vessel injury (1 rabbit), tendon injury (2 rabbits), postoperative hematoma (1 rabbit), and infection (1 rabbit) occurred in group A, postoperative infection (1 rabbit) in group C, and no postoperative complications in group B; the complication rate of group A (50%) was significantly higher than that of groups B (0%) and C (10%) (P<0.05). The radiological examination showed bone defects were fully repaired in groups A and B at 15 weeks, but bridging callus formation was observed in group C. There was no significant difference in BMC and BMD among 3 groups (P>0.05). HE staining and Masson staining results showed bone formation in group A, with structure disturbance and sclerosis. New bone formed in groups B and C, cartilage cells were observed in the center of bone cells. ConclusionThe radius bone defect model established by approach between extensor carpi radialis muscle and flexor digitorum profundus is an ideal model because of better exposures, less intra-operative blood loss, less complications. Interosseous membranes play a role in bone tissue repair process, and the mechanism needs further study.

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        • Research on non-contact respiratory rate measurement method based on video information

          Traditional methods of non-contact human respiratory rate measurement usually require complex devices or algorithms. Aiming at this problem, a non-contact respiratory rate measurement method based on only the RGB video information was proposed in this paper. The method consisted of four steps. Firstly, spatial filtering was applied to each frame of the input video. Secondly, a gray compensation algorithm was used to compensate for the gray level change caused by the environmental light. Thirdly, the gray levels of each pixel over time were filtered separately by a low-pass filter. Finally, the region of interest was determined based on the filtering results, and the respiration rate of the human is measured. The physical measurement experiments were designed, and the measurement accuracy was compared with that of the biological radar. The error of the proposed method was between ? 5.5% and 3% in different detection directions. The results show that the non-contact respiration rate measurement method can effectively measure the human respiration rate.

          Release date:2022-02-21 01:13 Export PDF Favorites Scan
        • Non-contact Heart Rate Estimation Based on Joint Approximate Diagonalization of Eigenmatrices Algorithm

          Based on the imaging photoplethysmography (iPPG) and blind source separation (BSS) theory the author put forward a method for non-contact heartbeat frequency estimation. Using the recorded video images of the human face in the ambient light with Webcam, we detected the human face through software, separated the detected facial image into three channels RGB components. And then preprocesses i.e. normalization, whitening, etc. were carried out to a certain number of RGB data. After the independent component analysis (ICA) theory and joint approximate diagonalization of eigenmatrices (JADE) algorithm were applied, we estimated the frequency of heart rate through spectrum analysis. Taking advantage of the consistency of Bland-Altman theory analysis and the commercial Pulse Oximetry Sensor test results, the root mean square error of the algorithm result was calculated as 2.06 beat/min. It indicated that the algorithm could realize the non-contact measurement of heart rate and lay the foundation for the remote and non-contact measurement of multi-parameter physiological measurements.

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        • An Algorithm for Microcirculatory Blood Flow Velocity Measurement Based on Trace Orientation in Spatiotemporal Image

          The velocity of blood in vessels is an important indicator that reflects the microcirculatory status. The core of the measurement technology, which is based on spatiotemporal (ST) image, is to map the cell motion trace to the two-dimensional ST image, and transfer the measurement of flow velocity to the detection of trace orientation in ST image. This paper proposes a trace orientation measurement algorithm is based on Randomized Hough Transformation and projection transformation, and it is able to estimate trace orientation and flow velocity in noisy ST images. Experiments showed that the agreement between the results by manual and by the proposed algorithm reached over 90%.

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        • Development of a balloon sensor device for force-electrical coupling measurement of esophagus

          To address the challenges of capturing micro-strains in detecting esophageal motility disorders and the limitations of existing high-resolution manometry and functional intraluminal imaging probes in directly measuring esophageal tissue electrical impedance, this study proposes a novel flexible balloon sensor structure that integrates a piezoelectric film assembly with a distributed impedance electrode array. Using the electrical analysis module in the finite element analysis (FEA) software, simulations of the forward problem for esophageal impedance detection were conducted to optimize the excitation source parameters, and a physical prototype was fabricated. Under a relative excitation mode with a voltage sensitivity of 2.059%, the voltage output characteristics of the impedance electrode array were analyzed during linear changes in the balloon filling volume. Based on the performance variation of the piezoelectric film assembly, 80% was selected as the optimal filling volume. Force-electric coupling tests were conducted on the balloon sensor using a pressure testing platform, revealing that both the piezoelectric film assembly inside the balloon and the impedance electrodes outside the balloon exhibited significant load differentiation characteristics as the force application point shifted. In summary, this balloon sensor facilitates the localization of force application while simultaneously analyzing esophageal tissue properties, offering a novel diagnostic approach and objective tool for esophageal disease detection.

          Release date:2025-06-23 04:09 Export PDF Favorites Scan
        • Research on classification of Korotkoff sounds phases based on deep learning

          Objective To recognize the different phases of Korotkoff sounds through deep learning technology, so as to improve the accuracy of blood pressure measurement in different populations. Methods A classification model of the Korotkoff sounds phases was designed, which fused attention mechanism (Attention), residual network (ResNet) and bidirectional long short-term memory (BiLSTM). First, a single Korotkoff sound signal was extracted from the whole Korotkoff sounds signals beat by beat, and each Korotkoff sound signal was converted into a Mel spectrogram. Then, the local feature extraction of Mel spectrogram was processed by using the Attention mechanism and ResNet network, and BiLSTM network was used to deal with the temporal relations between features, and full-connection layer network was applied in reducing the dimension of features. Finally, the classification was completed by SoftMax function. The dataset used in this study was collected from 44 volunteers (24 females, 20 males with an average age of 36 years), and the model performance was verified using 10-fold cross-validation. Results The classification accuracy of the established model for the 5 types of Korotkoff sounds phases was 93.4%, which was higher than that of other models. Conclusion This study proves that the deep learning method can accurately classify Korotkoff sounds phases, which lays a strong technical foundation for the subsequent design of automatic blood pressure measurement methods based on the classification of the Korotkoff sounds phases.

          Release date:2023-02-03 05:31 Export PDF Favorites Scan
        • A 30-year review and outlook on esophageal acid and pressure measurement

          The Department of Thoracic Surgery of Shanghai Chest Hospital has performed esophageal function testing for over 30 years, being the only department of its kind in China with this capability. The pressure testing and 24-hour pH/impedance monitoring of the esophagus is of great help to assist in the diagnosis and treatment of benign and malignant esophageal diseases related to it. Thanks to the esophageal function test, in addition to the routine various endoscopic anti-reflux procedures, our hospital has taken the lead in China in recent years to carry out a series of clinical and research work for benign esophageal diseases, such as the development of magnetic ring, double nedoscopic combination and new anti-reflux endoscopic techniques. In recent years, we have carried out high-resolution esophageal manometry and 24-hour pH/impedance monitoring for patients with interstitial pneumonia and pulmonary fibrosis suspected to be caused by gastroesophageal acid reflux. We can better assess the correlation between gastroesophageal reflux and pulmonary fibrosis, and to provide the different clinical treatments and even surgical interventions. The Bravo capsule is used more often in the United States, and it has obvious advantages over traditional approach for acid measurement. We strongly call for the collaboration between industry and academic institutions in this field, and the development of our own related products with independent intellectual property rights.

          Release date:2025-05-30 08:48 Export PDF Favorites Scan
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