The Hollow Fiber Membrane Oxygen Diffusion Permeability Test Data Acquisition System

Hollow fiber membranes technology is developed rapidly as a branch of membrane industry in recent years. In medical field, it is used to manufacture membrane oxygenator which would substitute for men's lung in surgical operation. Diffusion permeation ratio is a very important parameter of the hollow fiber membrane oxygenator's quality. However, using the chemical method to test diffusion permeation ratio can't monitor the impact of each parameter in experiments, it restricted the development of hollow fiber membrane technology to some extent.Multi-sensors data acquisition system was designed to monitor several parameters which impact diffusion permeation ratio of membrane oxygenator. The data of the parameters were transferred to the computer for further process and evaluation. Finally, the applications calculated the diffusion permeation ratio. This paper introduces the testing theory and experiment method of hollow fiber membrane, and expatiate the design and implementation of data acquisition system with emphasis.In the design of data acquisition system, universal serial bus (USB) and field programmable gate arrays (FPGA) technology were used. The data acquisition system communicates via USB interface. USB is plug-and-play interface between computer and add-on devices without external power supply, which is also fast, stable and low cost. As is available on almost every computer in the market, the USB is an excellent bus choice for data acquisition application.FPGA is a programmable device, which is fast, high frequency, low inner delaying, short develop cycle, rich logic resources, etc. In the design, the golden rule is top-down, and the AD converter auto acquisition control module, channel select module, digital demonstration module, frequency divider module, data buffer storage module use hardware description language to implement.The six channels data acquisition system consists of signal optimizing circuit, AD converter, FPGA logic control, data buffer storage and USB interface. The paper introduces the hardware design of sensor signals optimizing circuit and signal acquisition circuit in detail. The software including firmware, driver and application...