ABSTRACT
The purpose of this study was to explore transrectal ultrasound (TRUS) findings of prostate cancer (PCa) guided by multiparametric magnetic resonance imaging (mpMRI) and to improve the Prostate Imaging Reporting and Data System (PI-RADS) system for avoiding unnecessary mpMRI-guided targeted biopsy (TB). From January 2018 to October 2019, fusion mpMRI and TRUS-guided biopsies were performed in 162 consecutive patients. The study included 188 suspicious lesions on mpMRI in 156 patients, all of whom underwent mpMRI-TRUS fusion imaging-guided TB and 12-core transperineal systematic biopsy (SB). Univariate analyses were performed to investigate the relationship between TRUS features and PCa. Then, logistic regression analysis with generalized estimating equations was performed to determine the independent predictors of PCa and obtain the fitted probability of PCa. The detection rates of PCa based on TB alone, SB alone, and combined SB and TB were 55.9% (105 of 188), 52.6% (82 of 156), and 62.8% (98 of 156), respectively. The significant predictors of PCa on TRUS were hypoechogenicity (odds ratio [OR]: 9.595, P = 0.002), taller-than-wide shape (OR: 3.539, P = 0.022), asymmetric vascular structures (OR: 3.728, P = 0.031), close proximity to capsule (OR: 3.473, P = 0.040), and irregular margins (OR: 3.843, P = 0.041). We propose subgrouping PI-RADS score 3 into categories 3a, 3b, 3c, and 3d based on different numbers of TRUS predictors, as the creation of PI-RADS 3a (no suspicious ultrasound features) could avoid 16.7% of mpMRI-guided TBs. Risk stratification of PCa with mpMRI-TRUS fusion imaging-directed ultrasound features could avoid unnecessary mpMRI-TBs.
Subject(s)
Male , Humans , Prostatic Neoplasms/pathology , Multiparametric Magnetic Resonance Imaging , Magnetic Resonance Imaging/methods , Prostate/pathology , Image-Guided Biopsy/methodsABSTRACT
The purpose of this study was to analyze the value of transrectal shear-wave elastography (SWE) in combination with multivariable tools for predicting adverse pathological features before radical prostatectomy (RP). Preoperative clinicopathological variables, multiparametric magnetic resonance imaging (mp-MRI) manifestations, and the maximum elastic value of the prostate (Emax) on SWE were retrospectively collected. The accuracy of SWE for predicting adverse pathological features was evaluated based on postoperative pathology, and parameters with statistical significance were selected. The diagnostic performance of various models, including preoperative clinicopathological variables (model 1), preoperative clinicopathological variables + mp-MRI (model 2), and preoperative clinicopathological variables + mp-MRI + SWE (model 3), was evaluated with area under the receiver operator characteristic curve (AUC) analysis. Emax was significantly higher in prostate cancer with extracapsular extension (ECE) or seminal vesicle invasion (SVI) with both P < 0.001. The optimal cutoff Emax values for ECE and SVI were 60.45 kPa and 81.55 kPa, respectively. Inclusion of mp-MRI and SWE improved discrimination by clinical models for ECE (model 2 vs model 1, P = 0.031; model 3 vs model 1, P = 0.002; model 3 vs model 2, P = 0.018) and SVI (model 2 vs model 1, P = 0.147; model 3 vs model 1, P = 0.037; model 3 vs model 2, P = 0.134). SWE is valuable for identifying patients at high risk of adverse pathology.
Subject(s)
Male , Humans , Prostate/pathology , Seminal Vesicles/diagnostic imaging , Elasticity Imaging Techniques , Retrospective Studies , Extranodal Extension/pathology , Neoplasm Staging , Prostatectomy/methods , Prostatic Neoplasms/pathology , Magnetic Resonance Imaging/methodsABSTRACT
The purpose of this study was to evaluate the diagnostic performance of multiparametric ultrasound (mpUS; grayscale US, color Doppler US, strain elastography, and contrast-enhanced US) in the assessment of testicular lesions with negative tumoral markers. MpUS imaging data, patient age, serum tumor markers, scrotal pain, cryptorchidism, and related clinical information were retrospectively collected for patients who underwent mpUS examination between January 2013 and December 2019. Histologic results or follow-up examinations were used as the reference standard. In total, 83 lesions from 79 patients were included in the analysis. Fifty-six patients were finally diagnosed with benign tumors, and 23 patients were ultimately diagnosed with malignant tumors. Chi-square tests or Fisher's exact tests were used to assess the difference between the two groups. Stepwise multivariate logistic regression analysis showed that lesion diameter (odds ratio [OR] = 1.072, P = 0.005), vascularization on color Doppler US (OR = 4.066, P = 0.001), and hyperenhancement during the early phase (OR = 6.465, P = 0.047) were significant independent risk factors for malignancy; however, when compared with neoplastic lesions, pain (OR = 0.136, P < 0.001), absence of vascularization on color Doppler US (OR = 1.680, P = 0.042), and nonenhancement during the late phase (OR = 3.461, P = 0.031) were strongly associated with nonneoplastic lesions. MpUS features are useful for differentiating testicular lesions with negative tumoral markers and improving the preoperative diagnosis, which may avoid inappropriate radical orchiectomy.
Subject(s)
Male , Humans , Testicular Neoplasms/pathology , Biomarkers, Tumor , Retrospective Studies , Contrast Media , Ultrasonography/methodsABSTRACT
Purpose@#This study investigated the value of synchronous tele-ultrasonography (TUS) for naive operators in thyroid ultrasonography (US) examinations. @*Methods@#Ninety-seven patients were included in this prospective, parallel-controlled trial. Thyroid scanning and diagnosis were completed by resident A independently, resident B with guidance from a US expert through synchronous TUS, and an on-site US expert. The on-site expert’s findings constituted the reference standard. Two other off-site US experts analyzed all data in a blind manner. Inter-operator consistency between the two residents and the on-site US expert for thyroid size measurements, nodule measurements, nodule features, American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) categories, and image quality was compared. Two questionnaires were completed to evaluate the clinical benefit. @*Results@#Resident B detected more nodules consistent with the on-site expert than resident A did (89.4% vs. 56.5%, P0.75), while resident A achieved lower consistency in ACR TI-RADS categories, composition, echogenicity, margin, echogenic foci, and vascularity (all ICCs 0.40-0.75). Residents A and B had excellent consistency in target nodule measurements (all ICCs >0.75). Resident B achieved better performance than resident A for gray values, time gain compensation, depth, color Doppler adjustment, and the visibility of key information (all P<0.05). Furthermore, 61.9% (60/97) of patients accepted synchronous TUS, and 59.8% (58/97) patients were willing to pay for it. @*Conclusion@#Synchronous TUS can help inexperienced residents achieve comparable thyroid diagnostic capability to a US expert.
ABSTRACT
OBJECTIVE: To establish a method for the determination of formic acid in urine by automatic headspace-gas chromatography-mass spectrometry. METHODS: The urine sample was added with 3 mL 15.00%(V/V) sulfuric acid ethanol and heated in an automatic headspace sampler. The formic acid and ethanol underwent an esterification reaction to produce ethyl formate which was separated by gas chromatographic column and detected by mass spectrometer. The quantification was based on external standard method. RESULTS: The linear range of the method was 2.93-97.60 mg/L, with the regression equation correlation coefficient of 0.999 5. The detection limit was 0.65 mg/L and the minimum quantitative limit was 2.17 mg/L, with the recoveries of 95.61%-106.47%. The within-run relative standard deviation(RSD) ranged from 2.52% to 8.05% and the between-run RSD ranged from 6.58% to 8.42%. CONCLUSION: The method has simple pretreatment, good specificity, high precision and has little interference. It is suitable for large scale rapid determination of formic acid in urine in occupational contact population, patients with acute methanol poisoning and general population.
ABSTRACT
Objective: To identify the transcriptional activity and expression profile of PcMYB1, encoding a new R2R3-MYB transcription factor from Polygonum cuspidatum, and evaluate the biological functions of PcMYB1 in transgenic Arabidopsis thaliana. Methods: The yeast one-hybrid system assay was conducted to test the transcriptional activity of PcMYB1. The tissue-specific expression profiles of PcMYB1 and the gene expression of P. cuspidatum leaves in response to UV-C irradiation were analyzed by RT-PCR analysis. To assess the biological functions of PcMYB1, the gene was expressed in A. thaliana under the control of CaMV 35S promoter. To obtain information about the lignin composition, cross-sections of the basal part of the inflorescence stem of wild-type and transgenic A. thaliana plants were treated with Wiesner staining, and the lignin content was measured by acetyl bromide method. RT-PCR analysis was used to determine expression levels of the genes encoding the enzymes of lignin biosynthesis. Results: After expression of reporter and effector constructed in yeast, β-galactosidase assays showed that the transcriptional activation activity of VP16 domain was reduced markedly when fused to PcMYB1 protein, indicating that PcMYB1 has transcriptional repression activities. Expression pattern analysis showed that PcMYB1 was widely expressed in all tissues examined, but predominantly in leaves. PcMYB1 showed a peak of transcription at 6 h post UV-C treatment. The transgenic lines with reduction in height was 24.07% shorter than the wild-type plants. Wiesner staining of lignin in stem cross-sections revealed the typical intense red stain of secondary cell walls in wild-type plants, but less intense staining was detected in transgenic plants, and lignin accumulation was significantly decreased (about 14.81%) in transgenic plants stems. The expression of genes involved in the lignin biosynthetic pathway, including AtC4H, AtC3H, AtF5H, AtCOMT, and AtCAD, were down-regulated in transgenic lines compared to wild-type plants. Conclusion: Taken together, this study provided the evidence for the biological functions of PcMYB1 as a negative regulator of lignin pathway.
ABSTRACT
@#【Objective】To explore the clinical manifestation of COVID- 19 severe cases.【Methods】Clinical data of one severe case with COVID-19 including the clinical characteristic ，laboratory testing results，radiography，treatment，complication and outcome of the patient were retrospectively collected and analyzed.【Results】 The patient with COVID-19 was a 61-year old male，He suffered with underlying disease. His symptoms included fever，cough，myalgia， fatigue，and dyspnea. Laboratory testing results included normal WBC count，decreased lymphocyte cells，elevated LDH and hypoxemia. Radiography findings showed bilateral lung infiltration. His condition deteriorated after intensive treatment for one week. He was intubated and treated with mechanical ventilation because of complicating with severe acute respiratory distress syndrome（ARDS）.【Conclusion】COVID-19 is an emerging acute communicable disease，which lack specific and effective treatment. Most patients have a good prognosis but mortality in severe cases is high. More attention should be paid on the high risk of progression in COVID-19 cases.
ABSTRACT
OBJECTIVE@#To quantitatively investigate the effects of Ringer's solution with different concentrations of alcohol (1%～80%) on biphasic compound action potentials (AP) from frog sciatic nerve trunk, and their recoveries from alcohol effects.@*METHODS@#Individual segments of frog sciatic nerve trunk with a length of 6 to 8 cm were prepared. Ringer's solution with different concentrations of alcohol (0%, 1%, 2%, 4%, 8%, 16%, 32%, 48%, 64% and 80%) was applied onto the segment of the trunk between the stimulus and ground electrodes via an agent reservoir which was newly armed in a nerve trunk shielded chamber for 5 minutes. The nerve trunk was respectively electro-stimulated to generate the biphasic compound AP which was recorded using the experimental system of BL-420F. This was followed by 5 times washout plus 5 min administration with Ringer's solution before recovery recording of AP.@*RESULTS@#Compared to normal Ringer's solution, Ringer's solution with alcohol at ≤4% did not have dramatic impacts on the AP amplitude and conduction velocity, while Ringer's solution with alcohol at ≥8% there was significant decrease in these two parameters. Ringer's solution with alcohol at the conentrations of 16%, 32% and ≥48% could prevent a small proportion (30%), a large proportion (90%) and all (100%) of sciatic nerve trunks, respectively, from generating AP. Washout with normal Ringer's solution after alcohol application at the concentration of ≤32%, AP could totally recover to normal status. While alcohol at the concentration of 48%, 64% and 80%, the probabilities to regenerate APs were 90%, 40% and 0%, and the AP amplitudes were decreased to 60%, 36% and 0%, respectively. After washout, AP conduction velocity showed no difference with alcohol at the concentration of ≤8% when compared with that before washout, while it could not be recovered to normal under alcohol at ≥16%.@*CONCLUSION@#Ringer's solution with different concentrations of alcohol exerts different effects on biphasic compound AP amplitude and conduction velocity. Hopefully, our findings could be helpful for the alcoholic usage and its recovery from alcoholic damage.
Subject(s)
Animals , Action Potentials , Anura , Ethanol , Pharmacology , Ringer's Solution , Pharmacology , Sciatic NerveABSTRACT
Ultrasound (US) elastography has been introduced as a non-invasive technique for evaluating thyroid diseases. This paper presents a detailed description of the technical principles, peculiarities, and limitations of US elastography techniques, including strain elastography and shear-wave elastography. This review was conducted from a clinical perspective, and aimed to assess the usefulness of US elastography for thyroid diseases in specific clinical scenarios. Although its main focus is on thyroid nodules, the applications of US elastography for other thyroid diseases, such as diffuse thyroid diseases and thyroiditis, are also presented. Furthermore, unresolved questions and directions for future research are also discussed.
Subject(s)
Elasticity Imaging Techniques , Thyroid Diseases , Thyroid Gland , Thyroid Nodule , Thyroiditis , UltrasonographyABSTRACT
Objective@#Based on the dual-factor model of mental health, this study aims to explore the effects of acceptance and commitment therapy on the mental health of high school students.@*Methods@#During Oct. to Nov. 2017, General Health Questionnaire12(GHQ-12) and Depression Anxiety and Stress Scale21(DASS-21) was administered among 543 high school students from a middle school in Nanchang. According to the inclusion and exclusion criteria, 20 high school students were screened and were randomly assigned to the intervention group and control group, respectively. The intervention group received one intervention (1.5 h) per week for 8 weeks. The control group did not receive the intervention. Pre-and post-intervention assessment were conducted using the Acceptance and Action Questionnaire-2nd Edition (AAQ-II), the Cognitive Fusion Questionnaire-Fusion (CFQ-F), the Satisfaction With Life Scale (SWLS), the Positive Affect Scale (PAS), the GHQ-12, and the DASS-21.@*Results@#After intervention, the post-test scores of AAQ-II, CFQ-F, GHQ-12, and DASS-21 in the intervention group significantly decreased (t=2.91, 2.47, 4.91, 4.42, P<0.05) and the post-test score on PAS significantly increased (t=-5.27, P<0.01). There were no statistical changes in AAQ-II, CFQ-F, GHQ-12, and DASS-21 scores in the control group after intervention (t=-1.25, -0.09, -0.61, -0.69, -0.81, P>0.05).@*Conclusion@#Acceptance and commitment therapy can effectively improve the psychological flexibility and positive emotions, as well as alleviate general psychological distress and negative emotions, and promote the improvement of mental health of high school students.
ABSTRACT
Objective To investigate the risk factors associated with clinical prognosis of cervical cancer treated with laparoscopic surgery. Methods 80 patients with cervical cancer were recruited in the study, who underwent radical surgery with laparoscopic surgery from March 2013 to December 2016. The patients were followed up after surgery, and the overall survival and disease free survival was analyzed with tumor recurrence and death as the terminal events. And the risk factors associated with clinical prognosis were identified by using Cox regression analysis. Results The patients were followed up from 12 months to 46 months, and the median period was 39 months. There were 16 recurrences and 6 deaths during the period of follow-up, yielding a disease-free survival of (41.85 ± 1.06) year and an overall survival of (44.86 ± 0.74) year. Cox regression analysis demonstrated that tumor size, clinical stage, lymph node metastasis and vascular invasion were independent risk factors associated with clinical prognosis of cervical cancer treated with laparoscopic surgery. Conclusion Tumor size, clinical stage, lymph node metastasis and vascular invasion were independent risk factors associated with clinical prognosis of cervical cancer treated with laparoscopic surgery.
ABSTRACT
Objective To investigate the risk factors associated with clinical prognosis of cervical cancer treated with laparoscopic surgery. Methods 80 patients with cervical cancer were recruited in the study, who underwent radical surgery with laparoscopic surgery from March 2013 to December 2016. The patients were followed up after surgery, and the overall survival and disease free survival was analyzed with tumor recurrence and death as the terminal events. And the risk factors associated with clinical prognosis were identified by using Cox regression analysis. Results The patients were followed up from 12 months to 46 months, and the median period was 39 months. There were 16 recurrences and 6 deaths during the period of follow-up, yielding a disease-free survival of (41.85 ± 1.06) year and an overall survival of (44.86 ± 0.74) year. Cox regression analysis demonstrated that tumor size, clinical stage, lymph node metastasis and vascular invasion were independent risk factors associated with clinical prognosis of cervical cancer treated with laparoscopic surgery. Conclusion Tumor size, clinical stage, lymph node metastasis and vascular invasion were independent risk factors associated with clinical prognosis of cervical cancer treated with laparoscopic surgery.
ABSTRACT
Objective To establish a 3D finite element model of cervicothoracic spinal segments C5-T2 based on CT images and test its validity and effectiveness. Methods By using the Mimics, Geomagic and Hypermesh software, the 3D model of cervicothoracic spinal segments C5-T2 was reconstructed, repaired and pre-processed. Moment of ±0.5, 1, 1.5, 2 N•m were applied on top of the model to simulate loads produced during the flexion and extension movement of human body. The range of motion (ROM) of the segments C5-T2 during flexion and extension was calculated by ANSYS, and the reliability of the model was verified by comparing the experimental results in the previous literature with the finite element analysis results obtained in this study. Results Under the moment of 1 N•m, the ROMs of C5-6, C6-7, C7-T1 and T1-2 during flexion were 4.30°,3.21°,1.66° and 1.41°, and those during extension were 3.47°, 2.86°, 0.96° and 0.92°, respectively. The maximum stress during flexion appeared on the front of the vertebral body, while that during extension appeared on the back of the vertebral body. The trends of ROM and stress distributions were consistent with results reported in the previous literature. Conclusions The 3D model established in this study is accurate and realistic, and conforms to biomechanical properties of the cervicothoracic spine. The simulation results can be further used to explore clinical pathology of the spine and provide theoretical references for evaluation on cervicothoracic spine surgery.
ABSTRACT
Traditional Chinese medicine (TCM) has been formed and developed in medical practices over thousands of years, while biomechanics as a new research direction in TCM has been developing rapidly in recent years. Biomechanics in TCM encompasses abundant contents, such as hemodynamics in meridians, substance transport of Yin-Yang and the Five Elements, hemodynamics of pulse manifestation, heat conduction in tongue diagnosis, biomechanics of orthopaedics and traumatology, mechanics of acupuncture, massage and manipulation, TCM medical device, biomechnopharmacology and etc. Journal of Medical Biomechanics has published some papers about TCM biomechanics in the past years, and in this issue, a special column of TCM biomechanics in three research directions is organized, including massage and manipulation, fracture fixator by TCM treatment, and Tai Chi Quan, so as to arouse readers’ interest in TCM biomechanics.
ABSTRACT
Objective To investigate the imaging features of active Crohn′s disease on conventional ultrasound and contrast-enhanced ultrasound (CEUS). Methods The imaging features of 20 patients with an established diagnosis of Crohn′s disease on transabdominal high-frequency ultrasound and contrast-enhanced ultrasound in Shanghai Tenth People′s Hospital from August 2011 to December 2012 were studied retrospectively. Contrast-specific imaging modes were performed and the ultrasound contrast agent was SonoVue. The thickness of inner, outer and all layers of intestinal walls in the lesion area were observed;the ratio between inner and outer bowel wall thickness was calculated;Limberg classiifcation was determined by Power-Doppler results. Likewise, contrast-enhanced ultrasound was used to evaluate the degree and area of bowel wall enhancement, as well as the changes over time. Variance analysis was applied to compare intestinal wall thickness, arrive time of contrast agent, time to peak and washing time of patients with Crohn′s disease from different Limberg groups, and further comparison between groups were anlysed with LSD-t test. Results The intestinal wall thickness of all 20 patients was larger than 4 mm, while the mean thickness of intestinal walls was (8.8±0.4) mm (range 5.5-12.0 mm);the ratio between inner and outer wall thickness was greater than 1.0. Limberg classiifcation wasⅡin 2 patients,Ⅲin 8 patients andⅣin 10 patients. There were two enhancement patterns shown on contrast-enhanced ultrasound:Pattern 1 in 13 (13/20, 65.0%) patients showing simultaneous enhancement in both inner and outer intestinal walls at the same time. Pattern 2 in 7 (7/20, 35.0%) patients showing outward enhancement from inner to outer wall with a predominance of inner wall. The wall thicknesses of patients with Crohn′s disease from Limberg Ⅱgroup, Limberg Ⅲgroup and Limberg Ⅳgroup were (6.6±0.1), (7.5±0.4) and (10.2±0.4) mm respectively. The thicknesses of inner bowel walls were (3.6±0.6), (5.0±0.2) and (7.3±0.3) mm respectively. CEUS time to peak was (30.5±2.1), (26.9±2.4) and (21.0±1.6) s respectively. The wash-in time of the contrast agent was (18.0±5.7), (10.6±1.0) and (8.7±1.2) s respectively. As the Limberg level increased, the thickness of the entire and inner bowel wall both increased, while CEUS time to peak and wash-in time of the contrast agent became longer. These difference was statistically significant. In addition, the ratio between inner and outter wall thickness also increased as the Limberg level increased, however, the difference was statistically insigniifcant. Likewise, the outer bowel wall thickness and the arrival time of the contrast agent in patients with Crohn′s diseases from different Limberg level groups showed no statistical significance. Conclusions The patients with active Crohn′s disease always showed thickened bowel walls, higher Limberg level and complete or partial enhancement of bowel wall on CEUS. There were some correlations between the above-mentioned ifndings.
ABSTRACT
Objective To assess the accuracy of puncture guided by intelligent positioning (IP) system using magnetic navigation.Methods Five prepared targeted models at three certain depth (100 mm,large depth) underwent puncture guided by intelligent positioning system using IP and conventional ultrasound (US),respectively.Puncture errors,the number of attempt and spent time were recorded and compared .Results For the targets at small,medium and large depth,the errors of IP was (1.88 ±1.18),(1.56 ±0.56) and (3.99 ±1.10) cm,and the errors of conventional US was (4.52 ±2.23),(4.49 ±1.73) and (3.93 ±2.19) cm respectively.The errors of IP were significantly less than those of conventional US at small(t=-2.345,P=0.047) and medium(t=-3.608,P=0.007) depth,but there was no statistically significant difference at large depth (t=0.058,P=0.955). In the IP group,there were statistically significant differences for puncture errors between the small and large depth,as well as between medium and large depth ( F =8.923,P =0.010).There was no statistically significant difference for the errors of IP between the small and medium depth (t=-1.927,P=0.501).For the targets at small,medium and large depth,each puncture was performed in single attempt when guided by IP and in 2,1 and 2 attempt when guided by conventional US .At small and large depth,the numbers of attempt of IP were significantly less than those of conventional US (U=-2.372,P=0.018;U=-2.39, P=0.032).Whereas at medium depth,there was no significant difference (U=-1.000,P=0.690).For the targets at small,medium and large depth,each puncture spent (21.20 ±2.39)s, (27.00 ±4.00)s and (31.80 ±3.83)s when guided by IP,and(45.20 ±9.68),(26.80 ±4.21) and (54.60 ±13.48)s when guided by conventional US.The spent time of IP was less than that with conventional US for small and large depth targets(t =-5.383, P =0.001;t =-3.637, P =0.007).Whereas no statistically significant difference was found for the medium depth target (t=0.077,P=0.916).Conclusion In comparison with conventional US,IP system guided puncture is more accurate and the number of attempt and spent time is less .
ABSTRACT
Objective To make a quantitative research on the vertical force homogeneity of Yizhichan manipulation and look for the quantitative index and reference value which can describe the force homogeneity of Yizhichan manipulation effectively. Methods After the force homogeneity was described mathematically, the vertical force signals from Yizhichan manipulation operated by 5 experts, 5 skilled doctors and 5 beginners were measured and analyzed, respectively. Results The period homogeneities and the waveform homogeneities were obtained. No significant differences were found in the period homogeneities among the three groups, but significant differences appeared in waveform homogeneities between the beginner and expert group or the beginner and skilled doctor group. Conclusions The waveform homogeneities are more suitable for evaluating the vertical force homogeneity of Yizhichan manipulation by different operators, and 0.927 can be used as a reference value to evaluate the vertical force homogeneity of the operator.
ABSTRACT
Objective To raise a quantitative indicator for the waveform similarity between different signals of the same kind and apply it to the analysis on the vertical force signals from the rolling manipulation. Method After two signals of the same kind were normalized and their waveform errors were analyzed, the waveform similarity, which was to be utilized to describe the extent to which two signals were similar to each other, was defined. Then, the vertical force signals of the rolling manipulation operated by several experts, graduates who have learned the manipulation for some time and beginners were measured, respectively. Subsequently, the values of the waveform similarity between the three different groups of signals were calculated. Results The similarity between the experts’ signals was relatively high, so it was reasonable to be used as a template for other operators’ signals to be compared with. Further calculation revealed that the waveform similarity between the experts’ signals and the graduates’ was generally lower than that between the experts’, and the similarity between the experts’ and the beginners’ was the lowest. There was significant difference between the three groups. Conclusions The waveform similarity raised in this paper could serve as a quantitative indicator for the similarity between different vertical force signals from the rolling manipulation, and this method was also applicable to the similarity evaluation between other approximate periodic signals.
ABSTRACT
Objective To numerically simulate the blood flow in myocardial bridging parietal coronary artery and investigate the hemodynamics mechanism of the fact that atherosclerosis is more likely to occur in proximal segment of the parietal coronary artery. Methods The model, a straight tube with local stenosis which moved along with heart beating being used in order to simulate the morphology of myocardial bridging parietal coronary artery, was established. The wall of the tube was assumed as a thin wall linear elastomer, and the blood flow was assumed as a series of one dimensional flow equations following incompressible Newtonian fluid. The Lax-Wendroff method was also adopted to solve the governing equations numerically. Results There were significant differences in blood flow, wall shear stress and wall shear stress gradient between parietal coronary artery and normal coronary artery. For parietal coronary artery, the changes of wall shear stress and wall shear stress gradient were more dramatic in proximal segment than those in distal segment. As for two myocardial bridgings in one coronary artery, the trend of the wall shear stress and wall shear stress gradient was essentially the same, but the wall shear stress and wall shear stress gradient in myocardial bridging far from the ventricle were larger than those in myocardial bridging near the ventricle, with a more dramatic change along the time during one cardiac cycle. Conclusions Simulation results indicate that hemodynamics of parietal coronary artery is different from that of normal coronary artery. Changes of wall shear stress and wall shear stress gradient are more dramatic in proximal segment than those in distal segment, thus having an important impact on the local endothelial cells. It might be the hemodynamic mechanism of the fact that atherosclerosis is more likely to be developed in proximal segment of parietal coronary artery.
ABSTRACT
Objective To analyze the energy of rolling manipulation in different frequency bands and find the features of rolling manipulation dynamics. MethodThe force signals of rolling manipulation of six experts and six beginners were measured and divided into different frequency bands by wavelet transform to calculate the energy. Through statistical analysis, 18 characteristic quantities of horizontal force or vertical force were created and the overall evaluation coefficient R was proposed. ResultsAbout 70% of experts’ rolling manipulation energy was found in 0~0.406 25 Hz and about 20% energy in 1.625~3.25 Hz. The overall evaluation coefficient R of 6 experts was over 0.70, while R of beginners was below 0.70, which showed the difference was significant. ConclusionsThe energy distribution of rolling manipulation reflects the characteristics of softness and periodicity. If the rolling manipulation is in accordance with the manipulative requirement and the overall evaluation coefficients R is over 0.70, it could be said that the operator masters the rolling manipulation well.