Research on the cardiovascular function evaluation system based on noninvasive detection indices / 生物医学工程学杂志

Based on the noninvasive detection indeices and fuzzy mathematics method, this paper studied the noninvasive, convenient and economical cardiovascular health assessment system. The health evaluation index of cardiovascular function was built based on the internationally recognized risk factors of cardiovascular disease and the noninvasive detection index. The weight of 12 indexes was completed by the analytic hierarchy process, and the consistency test was passed. The membership function, evaluation matrix and evaluation model were built by fuzzy mathematics. The introducted methods enhanced the scientificity of the evaluation system. Through the Kappa consistency test, McNemer statistical results ( = 0.995 > 0.05) and Kappa values (Kappa = 0.616, < 0.001) suggest that the comprehensive evaluation results of model in this paper are relatively consistent with the clinical, which is of certain scientific significance for the early detection of cardiovascular diseases.

Simulation study on acoustic source reconstruction of magneto-acoustic tomography with magnetic induction (MAT-MI) based on transducer / 中国医疗器械杂志

<p><b>OBJECTIVE</b>In order to accurately reconstruct the acoustic source image, the application of transducer's receiving characteristics in magneto-acoustic tomography with magnetic induction (MAT-MI) is studied.</p><p><b>METHODS</b>The conductivity phantom model is built, and the magnetic acoustic signals are simulated and the acoustic sources are reconstructed according to the transducer's receiving characteristics.</p><p><b>RESULTS</b>The reconstructed image of acoustic source is consistent with the topographic shape and size of the phantom model.</p><p><b>CONCLUSION</b>MAT-MI based on the transducer's characteristics lays the foundation for further study.</p>

Research on acoustic source generating mechanism of magnetoacoustic tomography based on acoustic dipole theory / 生物医学工程学杂志

Magnetoacoustic tomography (MAT) has some advantages such as high sensitivity and high spatial resolution. The generating mechanism of acoustic source is the research foundation of forward and inverse problems. A coustic signals were respectively simulated by using monopole and dipole radiation theory in the experimental conditions, then the differences between their acoustic pressures were discussed, and furthermore the contrast and validation were conducted by physical experiments in this study. The physical experimental results showed that acoustic waveform of MAT had a certain directivity and therefore they indicated that dipole model showed higher approximation to the real facts than monopole model. It can be well concluded that this research has cardinal significance for the accurate algorithm of MAT.

The pilot observation of cerebral blood flow during aortic arch reconstruction surgery in piglet's animal model / 中华胸心血管外科杂志

ObjectiveA single pump and double arterial lines piglet model was established in this piglet's experiment.The preliminary study of cerebral blood flow proportion and distribution was performed continuously during the procedure.MethodsEight female piglets were utilized in this study.The body weight ranged from 18 kg to 22 kg.The right atrium was carmulated for venous drainage.Double arterial lines were established through cannulating into right carotid artery and ascending aortic aorta.Selective antegrade cerebral perfusion (SACP) through right carotid artery started after bladder temperature was decreased to 20℃ and the perfusion from ascending aortic aorta was interrupted.The perfusion through ascending aortic aorta resumed following 60 minutes of circulatory arrest.Traditional rewarming strategy was adopted and the experiment ended when bladder temperature attained 36℃.The real-time blood flow in the double arterial lines was monitored using a TS410 transit-time tubing flowmeter (Transonic Systems Inc.,Ithaca,NY).Blood pressure in femoral artery,intra-circuit pressure was recorded every five minutes interval.Regional cerebral oxygen saturation ( rSO2 ) was assessed with NIRO-200 oximeter using Near-infrared spectroscopy (Hamamatsu Photonics,Hamamatsu City,Japan )and mixed venous oxygen saturation ( SvO2 ).Blood samples were drawn for blood chemistry measurement prior to extracorporeal circulation,before circulatory arrest and at the end of experiment.ResultsArterial blood pressure was maintained at (60 ± 20) mm Hg.Total blood flow perfusion was(85.30 ±6.81)ml · kg-1 · min-1 and(14.42 ±1.76) ml · kg-1 · min-1 in right carotid artery.The proportion of cerebral blood flow was (16.72 ± 2.77 )％ of total perfusion.Cerebral blood perfusion was controlled with( 15.11 ± 0.44)ml · kg - 1 · min - 1 during SACP.Compared to SvO2,rSO2 remained stable during the procedure.The plasma concentration of

Results of 50 adult patients treated with extracorporeal membrane oxygenation for refractory postoperative cardiogenic shock / 中华胸心血管外科杂志

Objective Extracorporeal membrane oxygenation is a cardiopulmonary supportive therapy. Since 2004, our institution has adopted venoarterial ECMO for adult patients who otherwise could not be weaned from cardiopulmonary bypass and patients experiencing postcardiotomy cardiogenic shock and/or pulmonary dysfunction unresponsive to conventional treatment algorithms. In this study, we reviewed our experience with ECMO support and tried to identify measurable values which might predict in-hospital mortality. Methods From January 2004 through December 2008, 50 of 21,298 adult patients received VA ECMO. We retrospectively analyzed clinical records of these 50 consecutive patients. Demographics, preoperative measurements, clinical characteristics at the time of ECMO implantation, ECMO related complications and in-hospital mortality were collected. Logistic regression analyses were performed to investigate predictors of mortality. A p value ≤0. 05 was accepted as significant. Results Mean ECMO duration was ( 110 ± 17 ) hours. 38 patients were weaned from ECMO and 33 patients survived upon discharge. The overall survival was 66%. In univariate analyses, duration of ECMO support, receiving cardiopulmonary resuscitation prior to ECMO setup, ECMO setup in ICU, pre-ECMO plasma lactate level, infection, lower limbs ischemia, renal failure, experiencing at least one ECMO related complications were all associated with in-hospital death. In a multiple logistic regression adjusted for other factors mentioned above, blood lactate level before initiation of ECMO was a risk factor associated with in-hospital mortality (OR 1. 27 95% CI 1. 042-1. 542 ). To evaluate the utility of pre-ECMO lactate in predicting mortality, a conventional receiver operating characteristic curve was produced. Sensitivity and specificity were optimal at a cut-off point of 12.6 mmol/L, with an AUC of 0. 752. The positive and negative predictive values were 73.3% and 83.9% respectively. Conclusion ECMO is a justifiable alternative treatment for postoperative refractory cardiac and pulmonary dysfunction which could rescue more than 60 percent of otherwise fatal patients. Patients with pre-ECMO lactate above 12.6mmol/L are at higher risks for in-hospital death. Evidence based therapy for this group of high risk patients is needed.