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Interventional embolization therapy is widely used for procedures such as targeted tumour therapy, anti-organ hyperactivity and haemostasis. During embolic agent injection, doctors need to work under X-ray irradiation environment. Moreover, embolic agent injection is largely dependent on doctors' experience and feelings, and over-injection of embolic agent can lead to reflux, causing ectopic embolism and serious complications. As an effective way to reduce radiation exposure and improve the success rate of interventional embolization therapy, embolic agent injection robot is highly anticipated, but how to decide the injection flow velocity of embolic agent is a problem that remains to be solved. On the basis of fluid dynamics simulation and experiment, we established an arterial pressure-injection flow velocity boundary curve model that can avoid reflux, which provides a design basis for the control of embolic agent injection system. An in vitro experimental platform for injection system was built and validation experiments were conducted. The results showed that the embolic agent injection flow speed curve designed under the guidance of the critical flow speed curve model of reflux could effectively avoid the embolic agent reflux and shorten the embolic agent injection time. Exceeding the flow speed limit of the model would lead to the risk of embolization of normal blood vessels. This paper confirms the validity of designing the embolic agent injection flow speed based on the critical flow speed curve model of reflux, which can achieve rapid injection of embolic agent while avoiding reflux, and provide a basis for the design of the embolic agent injection robot.
Subject(s)
Embolization, Therapeutic/methodsABSTRACT
Objective To explore hemodynamic performance of the aortic dissection after lesions, so as to provide a more scientific basis for patient treatment. Methods Based on computed tomography angiography (CTA) image data from a patient with complex Stanford B-type aortic dissection, the personalized aortic dissection models with different rupture shapes (H-type, O-type, and V-type) at proximal end of the aortic dissection were established. Combined with computational fluid dynamics (CFD) and morphological analysis method, distributions of the velocity at rupture section, the blood flow, the wall pressure and the wall shear stress (WSS) were analyzed. Results The flow velocity, the highest pressure difference and the WSS proportion at entrance of the H-shaped rupture showed larger hemodynamic parameters than those of the other two types. The risk of dissection rupture for type H was the largest, while type V was in the middle, and type O was the smallest. Conclusions This study provides an effective reference for further numerical analysis the cases and formulation of treatment plans.
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Objective To develop a method for monitoring unconstrained sleep respiration suitable for daily use at home, so as to realize high precision screening of sleep apnea syndrome (SAS) or other respiratory diseases without affecting normal sleep. Methods A new unconstrained measurement method using sheet-type flexible pressure sensor was proposed. This method could obtain the information of respiratory motions of the chest and abdomen by measuring the pressure fluctuations of the chest and abdomen acting on the mattress. Experiments were conducted on ten healthy subjects to confirm effectiveness of the proposed method by comparing the result of the unconstrained measurement and those of respiratory inductance plethysmography (RIP) using band sensors, respectively. Results Sheet-type flexible pressure sensor could measure the pressure fluctuations of the chest and abdomen acting on the mattress during respiration and obtain respiratory waveform and respiratory rate. The respiratory rate measured with the sheet-type flexible pressure sensor agreed with those obtained by RIP. The gender and the lying position greatly affected whether the phases of the pressure fluctuations of the chest and abdomen measured with the flexible sensor differed from those obtained by RIP. The chest respiratory finite element model was established to analyze the phase difference of respiratory movement. Conclusions Sheet-type flexible pressure sensor is effective to monitor unconstrained sleep respiration, indicating the potential to identify the SAS types. But further researches of motion decoupling are required to identify the phase difference between the chest motion and the abdomen motion, which are coupled with each other.
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By analyzing the physiological structure and motion characteristics of human ankle joint, a four degree of freedom generalized spherical parallel mechanism is proposed to meet the needs of ankle rehabilitation. Using the spiral theory to analyze the motion characteristics of the mechanism and based on the method of describing the position with spherical coordinates and the posture with Euler Angle, the inverse solution of the closed vector equation of mechanism position is established. The workspace of mechanism is analyzed according to the constraint conditions of inverse solution. The workspace of the moving spherical center of the mechanism is used to match the movement space of the tibiotalar joint, and the workspace of the dynamic platform is used to match the movement space of subtalar joint. Genetic algorithm is used to optimize the key scale parameters of the mechanism. The results show that the workspace of the generalized spherical parallel mechanism can satisfy the actual movement space of human ankle joint rehabilitation. The results of this paper can provide theoretical basis and experimental reference for the design of ankle joint rehabilitation robot with high matching degree.
Subject(s)
Humans , Ankle Joint , Biomechanical Phenomena , Movement , Range of Motion, ArticularABSTRACT
Objective:To compare the survival outcomes in patients of small cell lung cancer (SCLC) with brain-single metastasis and brain with organs-multiple metastasis.Methods:Using the US surveillance, epidemiology and final results database, 5 520 SCLC patients with complete clinical information from 2004 to 2015 were selected. SCLC patients were adjusted, stratified or matched according to the metastasis site after the stratification or matching of the propensity scores, and the lung cancer-specific survival (CSS) rate and overall survival (OS) rate were compared between brain-single metastasis group and brain with organs-multiple metastasis group. In addition, the effects of chemotherapy and radiotherapy in CSS between brain-single metastasis group and brain with organs-multiple metastasis group were compared.Results:Of the 5 520 SCLC patients, 2 658 cases was in the brain-single metastasis group, and 2 862 cases was in brain with organs-multiple metastasis group. After the stratification or matching of the propensity scores, the median survival time in brain-single metastasis group was significantly longer than that in brain with organs-multiple metastasis group (6 months vs. 4 months), and there was statistical difference ( P<0.05). The fatality rate in brain-single metastasis group was significantly lower than that in brain with organs-multiple metastasis group (80.66% vs. 85.96%), and there was statistical difference ( P<0.01). Kaplan-Meier survival curve analysis result showed that the OS rate and CSS rate in brain-single metastasis group were significantly higher than those in brain with organs-multiple metastasis group (14.72% vs. 9.50% and 19.34% vs. 14.04%), and there were statistical differences ( P<0.05). Cox analysis result showed that age, race, T stage, gender, N stage, radiotherapy, chemotherapy, tumor diameter, marriage and metastasis were the influencing factors of CSS rate in SCLC patients with brain metastasis ( P<0.01 or <0.05). Multivariate Logistic regression analysis result showed that radiotherapy and chemotherapy can significantly improve the CSS rate ( HR = 0.668 and 0.671, 95% CI 0.570 to 0.783 and 0.573 to 0.786, P < 0.01). Conclusions:The survival rate in SCLC patients with brain-single metastasis is higher than that of SCLC patients with brain with organs-multiple metastasis; chemotherapy and radiotherapy can improve the survival rate in SCLC patients with brain metastasis.
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The requirement for unconstrained monitoring of heartbeat during sleep is increasing, but the current detection devices can not meet the requirements of convenience and accuracy. This study designed an unconstrained ballistocardiogram (BCG) detection system using acceleration sensor and developed a heart rate extraction algorithm. BCG is a directional signal which is stronger and less affected by respiratory movements along spine direction than in other directions. In order to measure the BCG signal along spine direction during sleep, a 3-axis acceleration sensor was fixed on the bed to collect the vibration signals caused by heartbeat. An approximate frequency range was firstly assumed by frequency analysis to the BCG signals and segmental filtering was conducted to the original vibration signals within the frequency range. Secondly, to identify the true BCG waveform, the accurate frequency band was obtained by comparison with the theoretical waveform. The J waves were detected by BCG energy waveform and an adaptive threshold method was proposed to extract heart rates by using the information of both amplitude and period. The accuracy and robustness of the BCG detection system proposed and the algorithm developed in this study were confirmed by comparison with electrocardiogram (ECG). The test results of 30 subjects showed a high average accuracy of 99.21% to demonstrate the feasibility of the unconstrained BCG detection method based on vibration acceleration.
Subject(s)
Humans , Acceleration , Ballistocardiography , Electrocardiography , Heart Rate , Signal Processing, Computer-Assisted , VibrationABSTRACT
Objective To compare the application effects of percutaneous tracheotomy and the traditional tracheotomy for patients in ICU. Methods From February 2015 to June 2016,56 patients in ICU of the First Hospital of Ninghai County were selected in the research and randomly divided into two groups according to the digital table, with 28 cases in each group. The traditional group received traditional tracheotomy. The percutaneous group received the percutaneous tracheotomy. The surgical blood loss,operative time,incision length,scar area,incision healing time, mechanical ventilation time,survival rate and incision infection,subcutaneous emphysema,trachea collapse and other complications were compared between the two groups. Results The operative blood loss,operative time,incision length,scar area,incision healing time,mechanical ventilation time in percutaneous group were (3. 14 ± 0. 15) mL, (10. 02 ± 3. 53)min,(1. 52 ± 1. 52)cm,(1. 18 ± 0. 12)cm2 ,(3. 53 ± 0. 44)d,(5. 73 ± 1. 13)d,respectively,which in the control group were (7. 24 ± 1. 91)mL,(30. 98 ± 11. 72)min,(5. 26 ± 5. 26)cm,(5. 72 ± 1. 95)cm2 ,(7. 46 ± 1. 25)d,(5. 67 ± 1. 82) d,respectively,the blood loss,operative time,incision length,operation scar area,incision healing time between the two groups had statistically significant differences (t = 8. 635,8. 052,8. 155,8. 742,9. 251, all P < 0. 05). The survival rate of the two groups was 100. 0％ . The incidence rate of incision infection,subcutaneous emphysema,trachea collapse in the percutaneous group was 17. 86％ ,which was significantly lower than 64. 29％ in the traditional group,the difference was statistically significant(χ2 = 15. 014,P < 0. 05). Conclusion Percutaneous tracheotomy and the traditional tracheotomy have certain effect for patients in ICU,compared with traditional tracheotomy, percutaneous tracheotomy has less blood loss, less operation time, can reduce the complications, and can replace traditional tracheotomy for rescue and treatment for ICU patients.
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Objective:To study the expression of caspase-3 and free radical injury in hypoxic-ischemic brain damage ( HIBD) of neonatal rats.Methods:All seven-day-old Wistar rats were randomly divided into HIBD group and sham operation group.Brains was obtained at time of 6 h,12 h,24 h,48 h,72 h,96 h after HIBD.Neuronal cell apoptosis was detected by terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling ( TUNEL).The expression level of caspase-3 protein was detected by immunohisto-chemistry.The level of malondialdehyde ( MDA) and supemxide dismutase ( SOD) were measured by thiobarbitic acid colorimetry and xanthin oxidase,respectively.Results:The number of neuronal cell apoptosis and the expression of caspase-3 protein began to increase at 6 h and reached the peak at 48 h in HIBD group,they were both significantly higher than those in the sham operation group at each time point (P<0.05).The level of MDA began to increase at 6 h and reached the peak at 24 h in HIBD group,it was significantly higher than the sham operation group at each time point (P<0.05).The level of SOD began to decrease at 6 h and reached the lowest level at 24 h in HIBD group,it was significantly lower than the sham operation group at each time point ( P<0.05 ) .The number of neuronal cell apoptosis and the expression of caspase-3 protein were positively correlated with the level of MDA, but they were negatively correlated with the level of SOD.Conclusion: Free radical injury promotes the expression of caspase-3 and neuronal cell apoptosis in HIBD.
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Objective To investigate the correlative factors affecting the plasma D-dimer level in elderly patients. Methods Five hundred and seventy-eight hospitalized elderly patients were included in this study. All participants were di-vided into normal group (＜0.4 mg/L) and elevated group (≥0.4 mg/L) according to the plasma D-dimer value,which was mea-sured by automated quantitative turbidimetric latex agglutination test. The differences in clinical indicators were compared be-tween two groups. The factors leading to the increased plasma levels of D-dimer in elderly patients were also analyzed. Results It was found that the patient age, C-reactive protein, prothrombin time, proportions of type 2 diabetes mellitus, ma-lignant tumor, bacterial pneumonia and (or) acute exacerbation of chronic bronchitis were significant higher in elevated group than those of normal group (P＜0.05), but the levels of total cholesterol and low density lipoprotein cholesterol were lower in elevated group than those of normal group (P＜0.05). There was a positive correlation between serum level of D-dimer and age, C-reactive protein (r=0.254 and 0.265, P ＜ 0.05). Binary logistic regression analysis showed that the factors affecting plasma D-dimer level of elderly patients were aging, elevated C-reactive protein level, existing of malignant tumor, type 2 dia-betes mellitus, and bacterial pneumonia and (or) acute exacerbation of chronic bronchitis. Conclusion Aging, existing of type 2 diabetes mellitus, malignant tumor, or acute inflammatory state were the important factors leading elevated plasma D-dimer levels in elderly patients.
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Objective To measure the level of interleukin-15(IL-15) in serum and its expression in lung tissues,and analyze the correlations between IL-15 and IL-4,IFN-?,eosinophil(Eos),and explore the effect of IL-15 on bronchial asthma.Methods Thirty femal BALB/C mice were randomly divided into three group(n=10),group A(asthma model),group B(corticosteroid treatment) and group C(normal control).All mice were killed 24 h after final OVA challenge.Blood were obtained for measurement of serum IgE,IL-4,IFN-? and IL-15 levels by enzyme-linked immunoabsorbent assay(ELISA).Bronchoalveolar lavage fluid(BLAF) was collected for Eos count.The left lungs were isolated for pathological examination.The lung sections were stained with hematoxylin and eosin(HE).The expressions of IL-15 in lung tissues were measured by immunohistochemical SP method.Results ①The mouse asthma model appeared ethological changes specific to asthma,the Eos count in BALF was increased,and IgE and IL-4 levels in serum were also increased compared with control group(P