双道高精度数控医用信号仪的研制

Development of Double-channel Medical Signal Generator with High Precision and Digital Control

目的:研制出一种以单片机和高性能芯片为核心研制的医用信号仪。方法:主要利用单片机控制两片高精度数控频率和位相的IC(AD9833)和D/A转换IC(AD558)等,并利用LCD显示信号的相关参数。结果:该仪器可输出双道高精度频率和位相的正弦、三角、方波信号及各种生理信号。可用于人耳频率特性和人体阻抗特性的研究和教学;利用同时输出的两道位相差可数控的正弦信号,可方便地演示医学物理等教学中两简谐振动在不同频率、不同相位差、不同方向等情况下的合成,如拍频、李萨如图形等。结论:该智能仪器可广泛用于实验教学、临床测试和医疗仪器维修。

Objective： To develop a double-channel medical signal generator which is based on a singie-chip microcomputer and highly integrated device. Methods： Some integrated chips （IC）, including digital-controUed highly frequency and phase IC （AD9833） and D/A IC （AD9855）, are controlled by a singie-chip microcomputer. Furthermore, the relative parameters are showed by LCD. Results： This medical signal generator may output not only double channels accurate sine, square and triangle waveforms with digital -controlled frequency and phase at the same time, but also many kinds of physiological signal. Therefore, it is convenient to measure and teach about hearing, research and study on frequency characteristic of human ear and impedance characteristic of human body in medical science. Using double channels sine signal to show synthesis of two simple harmonic vibration under different frequency, phase difference and direction, such as beat frequency and Lissajous chart, is very easy for experiment of medical physics. Conclusions： This instrument is convenient for experiment teaching, clinic examining, maintaining of medical instrument.