An implantable axial blood pump was designed according to the circulation assist requirement of severe heart failure patients of China. The design point was chosen at 3 L/min flow rate with 100 mm Hg pressure rise when the blood pump can provide flow rates of 2-7 L/min. The blood pump with good hemolytic and anti-thrombogenic property at widely operating range was designed by developing a structure that including the spindly rotor impeller structure and the diffuser with splitter blades and cantilevered main blades. Numerical simulation and particle image velocimetry (PIV) experiment were conducted to analyze the hydraulic, flow fields and hemolytic performance of the blood pump. The results showed that the blood pump could provide flow rates of 2-7 L/min with pressure rise of 60.0-151.3 mm Hg when the blood pump rotating from 7 000 to 11 000 r/min. After adding the splitter blades, the separation flow at the suction surface of the diffuser has been reduced efficiently. The cantilever structure changed the blade gap from shroud to hub that reduced the tangential velocity from 6.2 m/s to 4.3-1.1 m/s in blade gap. Moreover, the maximum scalar shear stress of the blood pump was 897.3 Pa, and the averaged scalar shear stress was 37.7 Pa. The hemolysis index of the blood pump was 0.168% calculated with Heuser’s hemolysis model. The PIV and simulated results showed the overall agreement of flow field distribution in diffuser region. The blood damage caused by higher shear stress would be reduced by adopting the spindle rotor impeller and diffuser with splitter blades and cantilevered main blades. The blood could flow smoothly through the axial blood pump with satisfactory hydraulics performance and without separation flow.
摘要:目的：观察小儿反复性肺炎的发生与血微量元素的关系。方法:选择56例反复性肺炎患儿为观察组，与60例健康儿童作对照，分别测定血镉、铅、铜、锌、钙、镁、铁含量。结果:56例反复性肺炎患儿血锌、铁含量较对照组减低，差异有统计学意义（Plt;0.05）。结论:部分反复性肺炎的发生与血微量元素锌、铁缺乏有关。应对反复性肺炎患儿常规行血微量元素检测，对血微量元素缺乏者应予相应补充治疗。Abstract: Objective: To observe the relationship to the occurrence of repeated pneumonia and the microelement in blood. Methods: We chose the 56 infant patients who suffered from repeated pneumonia as the observe group while the 60 health infants as the comprise group, then test the content of cadmium， plumbum， cuprum， zinc， calcium， magnesium and ferrum in blood. Results: The content of zinc and ferrum in the patient’s blood was lower than the comparison group, and the P value was Plt;0.01 and Plt;0.05 respectively, there was obvious differentiation between the two groups. Conclusion: Occurence of part repeated pneumonia is related to the deficiency of the microelements zinc and ferrum in blood. We should detect the common content of microelement to the infant patients who suffer the repeated pneumonia, and give a complement treatment to the microelements’ deficiency infant patients.
Objective To investigate the value of continuous blood purification （CBP）in early treatment of patients with ARDSexp （ARDS caused by extrapulmonary causes），especially in reducing inflammation mediators and extravascular lung water （EVLW）.Methods According the hospital admission sequence，the patients with APACHEⅡ scores from 15 to 20 and PaO2/FiO2 from 100 to 200 were recruited.The ARDSexp patients were divide into an intervention group treated with CBP （Mode：CVVHDF，rate of displacement liquid and dialysate：1.5 L/h，rate of blood：100-200 mL/h，and the time of CBP：72 hours），and a control group without CBP treatment. The NICO and PICCO monitoring data and the survival rates were recorded and analyzed using the SPSS software. Results The mortality rate of the intervention group was lower than that of the control group （6.3% vs. 36.8%，P=0.032）. In the 72 h monitoring dada of NICO and PICCO，the time of improving PCBF，Pm，Cdyn，VCO2，MValv，Pm，PIP，Raw，RSBI，Vd/Vt，and PaO2/FiO2 of the intervention group was severer than those in the control group，and the severety was also more than that of control group which was was significantly different at 72 h（Plt;0.05）. In the PICCO data，the time of decreasing EVWL and PVPI was shorter than the control group，and the decreasing extent was more than the control group，with significant difference at 72 h. But the changes of Apm，CI，and CVP were not significant （Pgt;0.05）. Conclusions In treatment of ARDSexp patients，CBP therapy can induce the PCBC and EVLW，improve pulmonary compliance and MValv，and reduce the mortality rate，while doesn’t influence heart function and the stability of circulation.
The use of Gore-tex artificial blood vessel in staged operation of arterialization was adopted in 19 cases having severe isehemic disorders of the lower extremities. Following 3 to 29 months after operation. with an average follow-up of 16.2 months. 16 cases had obtained better results, one cases had amputation because of thrombosis of the femoral artery and another one had developed thrombosis in the deep vein of the leg. It was considered that the application of short- sized Gore-tex artificial blood vessel in staged operation of arterialization to treat severe ischemic disorders of the lower extremities could provide satisfactory clinical resulst.
Since Oct. 1990, the 2nd metatarso-phalangeal joint and big-toe nail composite graft with the neuro-vascular bundle was transplanted to reconstruct the thumb in 4 cases. The transplants were all survived. The follow-up through 5 months, a comparatively good function and appearance were achieved.The applied anatomy, the surgical technique and the matters needing attention were detailed.
In recent years, many scholars have explored the clinical application value of a number of peripheral hematology indexes in tumor patients. The significant correlation of neutrophil to lymphocyte ratio and platelet to lymphocyte ratio with the prognosis in various tumors has also been confirmed. At present, more peripheral blood indexes have been gradually applied to the evaluation of the prognosis in patients with malignant tumors. Small cell lung cancer (SCLC) is a type of highly malignant tumor and most patients are in advanced stage at the time of diagnosis. The evaluation value of tumor stage for survival is extremely limited. Therefore, this review intends to explain the relationship between various peripheral hematology indexes and the prognosis of SCLC patients, so as to provide some academic evidence for the clinical assessment of the survival of SCLC patients and formulation of appropriate treatment strategy, which may contribute to the improvement of the prognosis.
Hemolysis is one of the main complications associated with the use of ventricular assist devices. The primary factors influencing hemolysis include the shear stress and exposure time experienced by red blood cells. In addition, factors such as local negative pressure and temperature may also impact hemolysis. The different combinations of hemolysis prediction models and their empirical constants lead to significant variations in prediction results; compared to the power-law model, the OPO model better accounts for the complexity of turbulence. In terms of improving hemolytic performance, research has primarily focused on optimizing blood pump structures, such as adjustments to pump gaps, impellers, and guide vanes. A small number of scholars have studied hemolytic performance through control modes of blood pump speed and the selection of blood-compatible materials. This paper reviews the main factors influencing hemolysis, prediction methods, and improvement strategies for rotary blood pumps, which are currently the most widely used. It also discusses the limitations in current hemolysis research and provides an outlook on future research directions.
The prevalence of cardiovascular disease in our country is increasing, and it has been a big problem affecting the social and economic development. It has been demonstrated that early intervention of cardiovascular risk factors can effectively reduce cardiovascular disease-caused mortality. Therefore, extensive implementation of cardiovascular testing and risk factor screening in the general population is the key to the prevention and treatment of cardiovascular disease. However, the categories of devices available for quick cardiovascular testing are limited, and in particular, many existing devices suffer from various technical problems, such as complex operation, unclear working principle, or large inter-individual variability in measurement accuracy, which lead to an overall low popularity and reliability of cardiovascular testing. In this study, we introduce the non-invasive measurement mechanisms and relevant technical progresses for several typical cardiovascular indices (e.g., peripheral/central arterial blood pressure, and arterial stiffness), with emphasis on describing the applications of biomechanical modeling and simulation in mechanism verification, analysis of influential factors, and technical improvement/innovation.
The successful suppression of clutter arising from stationary or slowly moving tissue is one of the key issues in medical ultrasound color blood imaging. Remaining clutter may cause bias in the mean blood frequency estimation and results in a potentially misleading description of blood-flow. In this paper, based on the principle of general wall-filter, the design process of three classes of filters, infinitely impulse response with projection initialization (Prj-ⅡR), polynomials regression (Pol-Reg), and eigen-based filters are previewed and analyzed. The performance of the filters was assessed by calculating the bias and variance of a mean blood velocity using a standard autocorrelation estimator. Simulation results show that the performance of Pol-Reg filter is similar to Prj-ⅡR filters. Both of them can offer accurate estimation of mean blood flow speed under steady clutter conditions, and the clutter rejection ability can be enhanced by increasing the ensemble size of Doppler vector. Eigen-based filters can effectively remove the non-stationary clutter component, and further improve the estimation accuracy for low speed blood flow signals. There is also no significant increase in computation complexity for eigen-based filters when the ensemble size is less than 10.
ObjectiveTo analyze the clinical characteristics, risk factors, and drug resistance of pathogenic bacteria in patients with blood stream infections (BSI) after orthopedic surgery, so as to provide reference and basis for clinical diagnosis and treatment.MethodsA retrospective analysis was made on the clinical data of 6 348 orthopedic patients admitted for surgery between January 2017 and December 2019. There were 3 598 males and 2 750 females. Their age ranged from 18 to 98 years, with an average of 66 years. The data of patients were collected, and the risk factors of BSI were analyzed by univariate analysis and logistic regression analysis. The distribution of BSI pathogenic bacteria, the results of drug sensitivity test, the incidence of BSI in patients after orthopedic surgery in different years, and the common sites of BSI secondary infection were summarized.ResultsBSI occurred in 106 (1.67%) of 6 348 patients after orthopedic surgery. There were 71 cases (66.98%) of secondary infection. The mortality of postoperative BSI patients was 1.89%, and the difference was significant when compared with that of non-postoperative BSI patients (0.24%) (χ2=5.313, P=0.021). The incidences of BSI in 2017, 2018, and 2019 were 1.18%, 1.53%, and 2.17%, respectively, showing an increasing trend year by year (trend χ2=6.610, P=0.037). Statistical analysis showed that the independent risk factors for BSI after orthopedic surgery (P<0.05) included the trauma, length of hospital stay≥14 days, emergency surgery, postoperative leukocyte counting<4×109/L, level of hemoglobin≤90 g/L, albumin≤30 g/L, the time of indwelling ureter>24 hours, use of deep vein catheter insertion, and merging other site infection. Blood culture showed 56 strains (52.83%) of Gram-positive bacteria, 47 strains (44.34%) of Gram-negative bacteria, and 3 strains (2.83%) of fungi. The top three pathogenic bacteria were coagulase negative Staphylococci (CNS; 36 strains, 33.96%), Escherichia coli (16 strains, 15.09%), and Staphylococcus aureus (15 strains, 14.15%). The detection rates of extended-spectum β-lactamases producing strains of Escherichia coli and Klebsiella pneumoniae were 56.25% (9/16) and 44.44% (4/9), respectively. The detection rates of methicillin-resistant strains in Staphylococcus aureus and CNS were 46.67% (7/15) and 72.22% (26/36), respectively.ConclusionPostoperative BSI in orthopedic patients is caused by multiple factors. Preventive measures should be taken according to related risk factors and perioperative risk assessment should be strengthened. Staphylococcus and Escherichia coli are the most common pathogenic bacteria in BSI after orthopedic surgery. The infection rate and drug-resistant bacteria are increasing year by year. Therefore, drug resistance monitoring should be strengthened.