Research And Application Of High-Precision Hypothermic Machine Perfusion System For Human Isolated Organ

The last decade has seen the rapid development of organ transplantation technique since the improvement of surgery level, proved to be an effective way to treat terminal stage diseases. However, the imbalance between the scanty organ supply source and huge potential market limits practical clinical application. Therefore, reducing the death rate of organs, preserved outside of the body, will bring a new breakthrough on organ transplantation in modern medical fields.The contribution of this thesis is to design a high-precision hypothermic machine perfusion (HMP) system for human isolated organ. The bloodstream is promoted and the energy is supplemented, then the ischemic organizations of organ are repaired and protected, by perusing a kind of blood-replaced solution, such as UW solution. In the instrument, some physiological parameters, such as the environment temperature, the PH level, the velocity of solution and the organ resistance, are detected and controlled to simulate human environment thus extending the lifetime of isolated organs.The designed HMP system utilizes TSic506 temperature sensor, the Hall impulse sensor, the hydraulic capsule and the PH electrode for physiological parameters collection respectively. It relies on next three key points:A) Low temperature can prevent ischemic organizations to become worse because of the slower biochemical reaction staying in a hypothermic environment; B) Though the isolated organ needs enough solution to wash away the metabolic waste inside, the strong flow may also lead to the organ edema and failure; C) Both flow resistance and potential of hydrogen reflect the real-time state of isolated organ exactly. The main software design of the instrument is based on DSP as well as FPGA framework, where DSP key technology includes:A) Combining the fuzzy control and fuzzy-PID control algorithm to drive the inverter compressor, and to improve the precision of temperature control; B) Making use of the modified bayes estimation-based multi-sensor data fusion algorithm to decrease the transfer error rate, and to maintain the system reliability; C) Carrying out the touch sensitive case control of medical care personnel. FPGA methods includes following aspects:A) Realizing the liquid crystal display and automatic threshold alarms of physiological parameters above; B) Building effective communication channel between DSP and FPGA chip. In addition, the ABS (acrylonitrile-butadiene-styrene) resin, with super insulating properties, is chosen as box body material and the nontoxic silica gel material is designed as solution duct. The sealing property of box as well as the overall arrangement of sensors and ventilations is also vital to achieve well temperature-controlled performance. Finally, the low power consumption and miniaturization of instrument has been considered in the thesis to meet the special vehicle-mounted requirement.In summary, the hypothermic machine perfusion system, based on the DSP and FPGA framework, takes the necessary physiological parameters of isolated organ into consideration The reliability and easy operationality make this instrument meet the consumer demand for patients who need organ transplantation and reduce the hospital load effectively, thus being appealing for future clinical application market.