| Objective: Heart failure(Heart Failure,HF)as the end stage of all kinds of cardiovasc ular disease,each year showed a growing trend and younger patients.As an effective way to treat heart failure,the research and development of artificial heart is a hot spot in the world,and it can be divided into two kinds: artificial heart and left ventricular assist device.During this paper,the development process of ventricular assist device in the problems faced by the core components of artificial blood pump using mechanical components,causing blood hemolysis,thrombosis and tissue compatibility issues unavoidably.But today the development of novel push alternating magnetic fluid(AC magnetohydrodynamic,AC MHD)artificial blood pump,the use of mechanical force to promote Lorenz blood flow replacement,no mechanical components in contact with blood,is expected to solve several generations of artificial blood pump organization has poor compatibility,blood hemolysis,thrombosis cannot permanently replace cardiac the problem.Methods: The blood pump based AC MHD artificial blood pump developed in this paper in the Research Institute of electrical Chinese on blood power house and motor frequency conversion and optimization(center field 0.9T,alternating motor frequency is 0-80hz),further in-depth research in parallel.The performance simulation using saline AC-MHD artificial blood pump blood test after modification,adjusting the magnetic field change frequency(i.e.,three-phase asynchronous motor speed),NaCl solution conductivity,power room and power of indoor NaCl solution before and after the ring number and the height of H,experimental tracer particle movement unit time for each condition in NaCl solution cond uctivity and the measurement of temperature,flow observation of dynamic indoor NaCl solution.According to the collected data,the optimal condition of the bleeding pump was a nalyzed,and the results were analyzed to optimize the blood pump device.On the basis of the performance test in front,the use of isolated sheep blood in AC MHD blood pump power room,at room temperature(25?),adjusting the frequency of magnetic field(i.e.three-phase asynchronous motor speed),blood level H by blood flow observation;blood routine blood samples were collected into tubes for the two groups,the control group(with out external magnetic field),exposure group(alternating magnetic field exposure more than3 hours,h=87mm)were tested for blood cell count,blood viscosity changes and by transmission electron microscopy(Transmission electron,microscope,TEM)to observe the ultra structural changes of blood cells.The results showed that the blood flow and the changes of the physical and chemical properties of blood cells were obtained.Results: The blood pump saline performance test: 1.Due to the axial path induced current is too low,we originally envisioned annular blood power house approximate aortic diameter(H=20mm,H=40mm),whether to change or increase the conductivity of conductive liquid plus motor frequency change,the flow rate was 0;2.The flow rate of the conductive liquid is proportional to the frequency of the external motor and the conductivity of the conductive liquid,and it is a two degree relationship with the height of the liquid;3.The best condition of the blood pump,when the electrical conductivity is 0.81s/m,the salt water is located in the longitudinal height of the H=100mm annular channel,when the fre quency of the motor is about 65 Hz,the maximum salinity is about 0.0115m/s.Blood pump isolated sheep blood test: 1.Sheep blood in AC MHD blood pump(motor frequency change of 70 Hz,H=100mm vertical annular channel)can realize continuous flow,the flow rate was 2mm/s,1.44ml/h;2.The blood cells by alternating magnetic field after exposure to the count had no obvious abnormalities,compared with the control group,the white blood cell was decreased,and the red blood cells and hemoglobin test despite the changes,but(P>0.05).Compared with the control group,the platelet count decreased(P=0.000(27)0.5);3 Sheep blood in alternating frequency 70 Hz,when the height of the annular channel H=100mm.Compared with the control group,the blood viscosity in sheep by alte rnating magnetic field after running 3h,whole blood viscosity decreased(p=0.006(27)0.05);low shear blood viscosity decreased,namely the above 0.001 p=0.000,there was statistical significance.Although the viscosity of whole blood increased slightly,but it(p=0.13>0.05).Compared with the control group,the plasma viscosity decreased significantly after high intensity alternating magnetic field(p=0.000(27)0.001);4.After high strength alternating magnetic field after the operation,the blood cells(mainly erythrocyte cytoplasm)was significantly better than the control group becomes shallow,particle aggregation and beaded phenomenon in the cytoplasm.Red blood cell morphology changed significantly,disc radian and cell volume larger than that of the control group 2.Through the analysis of 5000 times random 8 TEM results in normal red blood cell count(control group,43±1.32;exposure group,4±0.15)found that the typical biconcave structure in the control group in the alternating magnetic field disappeared after exposure.Conclusion: 1.Experiment proves that the research of AC magnetic fluid blood pump is feasible,can implement continuous flow blood flow;2.Experiments show that the optimal frequency of magnetic field the implementation of blood pump is 70 Hz,under this condition the blood pump energy conversion,and minimal impact on blood;3.Experiments show that as the complexity of the non Newtonian blood in alternating magnetic fluid pump,no obvious damage phenomenon of blood cells;4.Experiments show that the blood in vitro after alternating magnetic fluid blood pump after operation,the blood viscosity was exposed after other magnetic materials showed a downward trend;is different,because of the particularity of the alternating magnetic field change the change of viscosity,is not p articularly large;5.The experiment found that the isolated sheep blood after AC-MHD after acute exposure,the blood cells(mainly red cells)and internal structure The material has changed,and whether it will affect the function of blood cells will be the direction of our experimental evaluation. |
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