摘 要

微波治疗是利用微波与生物体的致热效应，对人体发生病变的组织进行消炎、止痛或清除，以达到治疗某些疾病的作用。微波治疗仪由于卓越的治疗效果，其疗效已得到医生和患者的广泛认可，但在微波输出功率的稳定控制方面依然差强人意，进而导致了病人在微波治疗过程中的安全隐患。

本设计的新型微波治疗仪，从控制系统的优化设计入手，实现了微波输出功率的稳定控制，即本次设计的核心目的。

本次微波治疗仪的控制系统设计将分为两大部分：硬件设计和软件设计。硬件设计主要包括DSC控制电路、A/D转换电路、D/A输出电路等。DSC通过控制磁控管的灯丝电流和阴极电压来调整微波输出功率，A/D转换电路和功率传感器用于监控微波输出，采用四通道数字隔离器隔离AD转换器和DA转换器的数字信号，相较于传统的光电耦合器功耗更低且数据传输速率更高。采用双通道高速光耦隔离DA转换器的片选信号，隔离效果良好。软件设计主要包括主程序、中断服务子程序、DS18B20温度转换程序等。

经仿真与调试，实现了预期的功能，满足设计要求，微波输出功率稳定。

关键词：微波治疗仪；控制系统；数字信号控制器；输出功率稳定

A Design of the Control System of Microwave Remedial Instruments

ABSTRACT

Microwave treatment is to use the heating effect of microwave and organism to reduce inflammation, relieve pain or clear away the diseased tissue in human body, so as to achieve the effect of treating some diseases. Due to its excellent therapeutic effect, microwave therapeutic instrument has been widely recognized by doctors and patients, but it is still unsatisfactory in the stability control of microwave output power, which leads to the hidden danger of patients' safety in the process of microwave treatment.

The new microwave therapeutic instrument designed in this paper realizes the stable control of microwave output power from the optimal design of the control system, which is the core purpose of this design.

The design of the microwave therapeutic instrument control system will be divided into two parts: hardware design and software design. The hardware design mainly includes DSC control circuit, A/D conversion circuit, D/A output circuit, etc. DSC adjusts the microwave output power by controlling the filament current and cathode voltage of the magnetron. A/D conversion circuit and power sensor are used to monitor the microwave output. A four-channel digital isolator is used to isolate the digital signals of AD and DA converters. The two - channel high - speed optocoupler is used to isolate DA converter chip - selected signal. Software design mainly includes the main program, interrupt service subroutine, DS18B20 temperature conversion program.

Through simulation and debugging, the expected function is realized, and the microwave output power is stable.

Keywords: microwave therapeutic apparatus; Control system; Digital signal controller; Stable output power

目 录

1. 绪论………………………………………………………………………………………….....1

1.1 研究背景与意义………………………………………………………………………....1

1.1.1 研究背景……………………………………………………………………….…..1

1.1.2 研究意义……………………………………………………………………….…..1

1.2 国内外研究现状…………………………………………………………………………1

1.3 研究内容………………………………………………………………………………....2

1.3.1 主要设计指标……………………………………………………………………...2

1.3.2 设计内容……………………………………………………………………….…..2

2 系统组成及工作原理………………………………………………………………….……….4

2.1 系统组成………………………………………………………………………………....4

2.2 系统工作原理…………………………………………………………………….……...4

2.3 本章小结………………………………………………………………………….……...5

3 控制系统硬件设计………………………………………………………………………….….6

3.1 硬件组成……………………………………………………………………………….....6

3.2 硬件结构框图……………………………………………………………………….…....6

3.3 DSC控制电路设计…………………………………………………………………........6

3.4 A/D转换电路设计………………………………………………………………...…......8

3.4.1 ADC引脚配置及外围电路………………………………………………….....…..8

3.4.2 隔离器件………………………………………………………………………........9

3.4.3 MCP3208工作时序…………………………………………………………….....10

3.5 D/A输出电路设计……………………………………………………………………...10

3.5.1 DAC引脚配置及外围电路…………………………………………………….....10

3.5.2 隔离器件…………………………………………………………………………..11

3.5.3 MCP4922工作时序………………………………………………………..…….. 12

3.6 触摸屏接口电路设计…………………………………………………………………...12

3.7 微波控制电路设计……………………………………………………………………...13

3.8 温度测量模块…………………………………………………………………………...13

3.8.1 DS18B20内部结构………………………………………………………...……..14

3.8.2 高速暂存器内部结构…………………………………………………………......14

3.8.3 DS18B20温度转换原理……………………………………………………….....15

3.8.4 DS18B20工作时序…………………………………………………………….....16

3.9 本章小结………………………………………………………………………….....18

4 控制系统软件设计…………………………………………………………………………....19

4.1 软件组成……………………………………………………………………………...…..19

4.2 主程序设计……………………………………………………………………………….19

4.3 中断服务子程序设计………………………………………………………………….....20

4.3.1 定时器中断………………………………………………………………………..20

4.3.2 A/D转换中断……………………………………………………………………..21

4.4 DS18B20温度转换子程序设计………………………………………………………....21

4.4.1 温度读取程序………………………………………………………………..........22

4.4.2 读字节程序…………………………………………………………………..........22

4.4.3 写字节程序…………………………………………………………………..........24