精确放疗精度提高的单片机控制方法研究

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3.0 牛悦 2024-11-19 4 4 2.82MB 71 页 15积分
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I
摘 要
癌症的发病原因比较复杂，预防比较难，因而在癌症发病后癌症的治疗以及
如何更加精确地进行癌症的治疗也成为人们研究的重点，特别是在胸腹部肿瘤的
治疗过程当中，临床数据显示由呼吸运动对放疗精度造成的影响比较大，国内外
已有的各种提高放疗精度的方法各有不足，使我们不得不关注这种情况下放疗精
度的控制，我们就是在这种情况下提出了研究的课题。
本课题主要是针对呼吸运动对精确放疗的影响问题，提出一种改进方法。胸
肺部或者上腹部的生理运动，特别是呼吸运动,造成精确放疗过程中靶区内的剂量
与预定剂量之间产生差别，这种差别造成肿瘤得不到有效的治疗，而且还将造成
周围正常组织受到射线的照射。本文提出一种以呼吸参数采集和单片机的控制为
关键技术的解决方法，来提高放疗精度，具体研究内容如下：
（1）呼吸参数的检测及表示方法，实现对个体的肺容积随呼吸（时间）而变
化的实时检测和描述。主要研究内容包括呼吸参数的采集方法、肺容积随时间变
化的数值算法及图形表示法、肺容积测定的标定方法以及检测、分析所基于的软
件开发等。由于呼吸参数采集的特殊性，我们采用非标准孔板式流量计进行呼吸
参数采集，且采用了一定的标定装置进行标定。
（2）运动曲线获取方法。通过螺旋 CT 扫描获得病人在正常呼吸状态下呼吸
运动器官位移随时间变化的曲线，由此而得到与呼吸参数相对应的器官及病变组
织在各个方向上的动度，通过对呼吸参数随时间变化的规律与图像中被测点相对
应的空间位置随时间而改变的规律这两者之间的关系的研究，可以建立起同一时
间坐标系下呼吸运动与器官位移变化关系的数学模型，分析并建立摆位床的运动
规律数学模型，使其能实时地、按器官运动规律逆向且同步地运动。
（3）选择适用的步进电机。在电机的选择与机械设计方面，尽量小型化、轻
便化。器官组织的运动轨迹是一三维运动方程，应分解成三个方向的运动并采用
三个步进电机分别控制，但考虑到研制成本等因素，在同样能达到研究目的的情
况下，拟采用两个步进电机，分别实现 X、Y轴方向的逆向运动控制，这样做虽
然忽略了 Z方向运动的影响，却不影响平面靶区的重合精度。
（4）单片机控制步进电机。单片机产生脉冲数控制旋转运动量和直线运动量，
用中断时间控制运动的频率，步进电机通过传动机构带动摆位床按照研究需要的
运动规律运动，从而实现克服器官位移对精确放疗的影响。
本研究通过将工程方法用于对放疗精度控制，具有广泛的应用价值。研究对
于精确放疗中放疗精度的进一步精确控制打下了基础。
II
关键词： 放疗精度 单片机 步进电机
III
ABSTRACT
Complicated factors and difficult prevention of cancer make the treatment and how
to carry out more precise treatment become the focus of the study. Especially in the
treatment process of chest and abdomen cancer, it’s showed by clinical data that
respiratory movement has relatively large impact on the accuracy of the radiotherapy.
Various ways to improve the accuracy of radiotherapy at home and abroad all have
weakpoints, thus we pay more attention to radiotherapy precision control and we put
forward this issue.
The issue is mainly about an improved method against effects of respiratory
movement on the precise of radiotherapy. Upon all the chest or upper abdomen physical
movements, the breathing exercise results in differences between the dose of target area
and scheduled, and the differences may not only flaw effective treatments, but also the
radiation exposure of surrounding normal tissue. This paper presents one way with
respiratory parameters acquisition and single-chip technology as key solutions to
improve the accuracy of radiotherapy. The specific research includes:
(1) The method of detection and representation to respiratory parameters, realizing
real-time detection and description to individuals with respiratory lung volume (time)
and changes .The study includes the major collection methods of respiratory parameters,
changes in lung volume over time numerical algorithm and graphical representation of
law, lung volume measurement and calibration method detection, analysis based on the
software development. Because of the specificity of respiratory parameters acquisition,
we have adopted a non-standard hole plate flowmeter for respiratory parameters
collection, and calibration device.
(2) Method of movement curve. We can get organ displacement curves change
over time by spiral CT scan while normal breathing of patients. So the mobility in all
directions of organs and diseased tissue corresponding on respiratory parameters .We
can establish the mathematical model about the relationship between the respiratory
parameters and organ displacement and canbuild the law of positioning bed to control
its simultaneously reverse movement.
(3) Choice of the applicable stepper motor. It’s as small size and light-based as
possible in electric and mechanical design. A trajectory of organs is a three-dimensional
equation of motion, and should be broken down into three directions of movement with
IV
three separate stepper motor control. Taking into account the development costs and
other factors, we propose using two stepper motor to achieve the same purpose of the
study, X and Y-axis motion control reverse direction. Although movement of Z axis is
ignored, the accuracy of coincidence plane target is not affected.
(4) Single-chip control to stepper motor. Pulses generated by singlechip control
rotary and linear exercise, and interrupted time control movement frequency. Stepper
motors drive positioning bed in accordance with the research through the transmission
anyway to overcome the impact to precise radiotherapy.
The research put engineering method into precision control. It has a broad
application value. Research lays the foundation for further precise control.
Keywords: radiotherapy accuracy, singlechip microcomputer, stepping motor
V
目 录
摘要
ABSTRACT
第一章 绪 论 ................................................................................................................... 1
§1.1 癌症.....................................................................................................................................1
§1.1.1 癌症的病发情况..................................................................................................... 1
§1.1.2 癌症病因探究.......................................................................................................... 1
§1.2 癌症的治疗方法..............................................................................................................2
§1.3 精确放疗........................................................................................................................... 5
§1.4 呼吸运动对胸腹部肿瘤靶区边界的影响............................................................... 6
§1.4.1 自主呼吸状态下肺部肿瘤的运动情况............................................................ 6
§1.4.2 腹部肿瘤受呼吸运动的影响.............................................................................. 6
§1.5 本章小结......................................................................................................................... 10
第二章 呼吸参数采集 ................................................................................................... 12
§2.1 呼吸参数采集硬件装置..............................................................................................12
§2.1.1 原理及公式.............................................................................................................13
§2.1.2 确定结构及参数................................................................................................... 14
§2.1.3 实验装置及参数................................................................................................... 15
§2.1.4 实验方法及内容................................................................................................... 16
§2.1.5 孔板式流量计特性曲线......................................................................................18
§2.2 数据采集系统的软件.................................................................................................. 20
§2.3 主要检测内容及要求.................................................................................................. 21
§2.3.1 检测内容（一）................................................................................................... 21
§2.3.2 检测内容（二）................................................................................................... 22
§2.3.3 检测内容（三）................................................................................................... 22
§2.4 运动曲线获取方法.......................................................................................................23
§2.5 本章小结......................................................................................................................... 25
第三章 精度控制系统 ................................................................................................... 26
§3.1 步进电机控制................................................................................................................ 26
§3.1.1 步进电机概述........................................................................................................ 26
§3.1.2 两相步进电机的工作原理.................................................................................28
§3.1.3 一般步进电机的参数.......................................................................................... 28
§3.1.4 步进电机的选择................................................................................................... 31
VI
§3.1.5 振动和噪音.............................................................................................................34
§3.1.6 加速和减速运动的控制......................................................................................34
§3.1.7 步进电机升降速曲线控制方法........................................................................35
§3.1.8 步进电机驱动........................................................................................................ 39
§3.2 放疗精度控制系统电路..............................................................................................39
§3.2.1 主控电路设计........................................................................................................ 40
§3.2.2 电机驱动设计........................................................................................................ 43
§3.3 通信接口电路................................................................................................................ 51
第四章 软件系统设计 ............................................................................................... 54
§4.1 主程序设计.....................................................................................................................54
§4.1.1 设计目的................................................................................................................. 54
§4.1.2 程序模块................................................................................................................. 55
§4.2 本章小结......................................................................................................................... 59
第五章 结论与展望 ................................................................................................... 61
符号表.............................................................................................................................62
参考文献.........................................................................................................................63
在读期间公开发表的论文和承担科研项目取得的成果.............................................66
致 谢.........................................................................................................................67
摘要：

I摘要癌症的发病原因比较复杂，预防比较难，因而在癌症发病后癌症的治疗以及如何更加精确地进行癌症的治疗也成为人们研究的重点，特别是在胸腹部肿瘤的治疗过程当中，临床数据显示由呼吸运动对放疗精度造成的影响比较大，国内外已有的各种提高放疗精度的方法各有不足，使我们不得不关注这种情况下放疗精度的控制，我们就是在这种情况下提出了研究的课题。本课题主要是针对呼吸运动对精确放疗的影响问题，提出一种改进方法。胸肺部或者上腹部的生理运动，特别是呼吸运动,造成精确放疗过程中靶区内的剂量与预定剂量之间产生差别，这种差别造成肿瘤得不到有效的治疗，而且还将造成周围正常组织受到射线的照射。本文提出一种以呼吸参数采集和单片机...

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作者：牛悦 分类：高等教育资料 价格：15积分 属性：71 页 大小：2.82MB 格式：PDF 时间：2024-11-19

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