Study On The Multi-Purpose Of Double-Ventricular Extracorporeal Blood Pump

Objective: By testing the multi-purpose function of double-ventricular extracorporeal blood pump designed by our team and transform methods of auxiliary cycle mode, this thesis is aimed at discussing the feasibility of the blood pump used in Cardiopulmonary bypass Methods of artificial oxygenator mode, autogenous oxygenator double ventricular mode and single ventricular assisted circulation or biventricular assisted circulation. Methods: Connected the multi-purpose biventricular circulation-assisting blood pump that was autonomously designed to the constructed testing equipment which simulated human systemic circulation, the oxygenation equipment that simulated traditional artificial lung, as well as the experimental testing equipment that simulated pulmonary circulation. Conducted simulation of traditional cardiopulmonary bypass mode for artificial lung oxygenation, and biventricular synchronized cardiopulmonary bypass mode for autologous lung oxygenation, as well as the simulation of transition from the extracorporal circulation-assisting bypass mode for both ventricles of the same flow rate into that for both ventricles of different flow rates which eventually turned into the extracorporal circulation-assisting bypass mode for one ventricle, respectively. Recorded the simulating hemodynamic change indices upon working of the blood pump through output variation, working for overcoming peripheral resistance, together with that for simulating the vascular compliance upon various elastic chambers, respectively; analyzed the experiment data and compared them to the expected clinical application value with an aim to assess whether the autonomously-designed blood pump satisfied the human hemodynamic requirements of traditional cardiopulmonary bypass mode, biventricular cardiopulmonary bypass mode for autologous lung oxygenation, as well as biventricular extracorporal circulation-assisting mode. Results: Under the certain experimental conditions and the volume of left pump and right pump is 70 ml, the results of artificial oxygenator mode are as follows. When mean arterial pressure reaches 90 mmHg and above, circular flow is 5.78L/min ~6.10 L/min. The difference compared with clinical expected value is-0.22 L/min ~0.10 L/min. Maximum differential pulse pressure is 28 mmHg. Compared with clinical expected value, the difference is-2 mmHg. The data from elastic chambers model experiment shows that the pump function of artificial oxygenator mode is similar to the pump function of human cardiovascular circulation system. Under the same experimental conditions, the results of autogenous oxygenator double ventricular mode are as follows. When circular flow of double-ventricular blood pump reaches the presets 5L/min, the difference of average circular flow between left pump and right pump is very small. There is without statistical significance(P=0.887). When simulated average artery pressure reaches 90 mmHg and above, the maximum average circular flow of simulated systemic circulation system is 6.07 L/min. The maximum aortic pulse pressure difference is 31 mmHg. When simulated pulmonary arterial mean pressure reaches 30 mmHg and above, the maximum average circular flow of simulated pulmonary circulation system is 6.09 L/min. The maximum pulmonary pulse pressure difference is 10 mmHg. The measured value basically agrees well with predicted value. Test results of double ventricular assisted circulation shows that under the conditions of not changing contractile frequency of pump, there are three different results by adjusting the pump chamber margin squeeze, as follow. The fir st result is the circular flow of left and right pump can increase simultaneously or reduce simultaneously. The second kind of result is that the circular flow of left pump is different from flow of right pump. The last result is that there is only one pump to output. In short, the change of circular flow of two pumps corresponds roughly to percentage of squeeze the amplitude change. Conclusion: 1. The double-ventricular extracorporeal blood pump designed by our team can meet different changes in the output of basic hemodynamic requirements which used in extracorporeal circulation mode of artificial oxygenator, autogenous oxygenator double ventricular and single ventricular assisted circulation or biventricular assisted circulation. 2. By testing control device of pump chamber margin squeeze can meet demand of smooth transition from the same flow biventricular extracorporeal circulation to the different flow biventricular extracorporeal circulation to the flow of single ventricle extracorporeal circulation.