| Renal failure and the corresponding nephrotic uremia has been a common critical disease all over the world.Either the clearance of the middle molecule in the blood or complications caused during dialysis are both shortcomings in traditional method of hemodialysis.The proposition of the "daily dialysis" idea and the progress in biological artificial kidney,to simulate the kidney function better,enable us to approach the complete renal replacement therapy.Portable hemofiltration instrument(PHI)is developed based on the concept of"daily dialysis".The clearance of the middle molecules of the toxin are improved by using the operating principle of "perfusion-ultrafiltration".At the same time,the dialysis method of ultrafiltration and displacement fluid’s preparation before dialysis,compared with traditional hemodialysis machine,save the water consumption remarkably,and also reduce the weight of the prototype in some extent,which leads to hemodialysis more family and communal.Based on the adjustment of biosensor and the feedback of the weighing sensor,we can compensate the displacement fluid dynamically according to the ultrafiltration of the waste liquid.Furthermore,the biological artificial kidney is a big trend,especially the combination of dialyzer and cell/tissue,which bestows the dialyzer metabolic and endocrine functions,in addition to common physical way to remove toxins.However,the cryopreservation of kidney cell is inevitable,and further exploration on the cell’s optimization of preservation need to be addressed.In this work,we design and develop the PHI,and verify its function and stability by carrying out systematic biochemical experiments.In addition,we do some exploration about the kidney cell’s cryopreservation.Specific research contents and results in this thesis are summarized as follows:(1)Develop the "perfusion-ultrafiltration" principle-based PHI’s principle prototype and technology demonstration prototype,and the corresponding hardware(PCB design)and software(control routine)system.The hardware system of the PHI is based on C8051F040 and C8051F320 MCUs,containing both serial port communications with electronic balance and blood detection sensor,IO port communication with air detection sensor,and the control of peristaltic pumps and electromagnetic valves,touchable display with simple function selection.The software system is accomplished in integrated development environment Silicon IDE.The main functions of the PHI’s control routine include SPI communication which enables data exchange between master and slave MCUs,the communication between the main MCU(C8051F040)and all the other biochemical sensors,the peristaltic pumps,LCD module,as well as the dialysis process control,alarm,etc.(2)Carry out comprehensive biochemical experiments to verify the function and stability of the PHI prototype,including the simulation experiments and the rigorous pig blood trial in vitro.By detecting the osmotic pressure of the DMSO/saline solution or urea/saline solution mixtures,we can obtain the corresponding clearances and give further evaluation on sufficiency.At the same time,we can learn about the prototype’ stability and robustness.The pig blood experiments in vitro,a strong evidence and complement of the simulation experiments,with comprehensive considerations on blood clotting,the internal pressure of pipeline and other conditions,puts forward new requirements on the choices of dialyzer and the piping design.(3)Explore and obtain the cryobiological parameters of human embryonic kidney cells(HEK293T),which is absolutely necessary for the future development of the biological artificial kidney system,and give prediction on the corresponding optimal cooling rate.By using common commercial low temperature microscopy,this paper acquires the HEK293T cells’ biophysics parameters,fitted with the experimental data under slow/fast cooling rates.According to GOCRE equations,we predict the optimal cooling rate of HEK293T cells,and provide key data basis for further optimization of the cell preservation. |
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