Continuous Renal Replacement Therapy Equipment(CRRT) Key Technology

The hemodialysis already had a development history for nearly a century. In recent years, CRRT was one kind of new blood purification technology, which developed in the hemodialysis foundation. It is a therapeutics breakthrough progress. It has been the main method in the field of intensive care unit(ICU) and has a good application prospect. CRRT has been generally applied in the ICU, in overseas. At present, our country dialysis market extremely broad, but because we didn't master the essential technology, so the equipment which is made in our country is serious short and bad quality. The system of control and inspect is not advanced and sensitive. The stability and reliability is not good.The CRRT machine essential technology mainly includes: blood stream dynamics stable control, blood and water trails monitoring, man-machine interactive function. It was the key technology to drive blood pump for steadily control blood stream. It was one of core technology to inspect blood leak for system of blood and water trails inspecting.In this paper, the main tasks were to design and test blood pump drive and blood leak inspecting. The Roller Pump and DC motor was chosen by analyzing the performance and characteristic of the blood pump and motor. On the basis of it, according to the characteristic and request of the CRRT blood pump, a new type power drive circuit to drive direct current motor was designed for the blood pump. The circuit had the function of thermal shutdown, current limiting, closed control loop of current and voltage. The experimental results indicated that the amplificatory circuit could linearly and steadily adjust the blood pump flux.It introduced a new method of blood leak inspecting -color identifying, according to the current technology of blood leak inspecting and in terms of the demand of blood leak inspecting for CRRT, which belonged to a medical treatment instrument Ltd. The new color sensor TCS230 was chosen to design the circuit of blood leak inspecting, on the basis of the color identification principle and the in-depth analysis of data disposal methods. Then, a simulative experimentation platform was built. Based on the experiment, the scheme was feasible.