超声波气泡检测.docVIP

摘要 随着科技的发展，医疗器械不断完善，在医疗行业占据了越来越重要的地位。在输液过程中输液管中若出现气泡，气泡进入病人体内会对病人产生不利影响，当气泡体积大于5mL时甚至会致病人死亡，为保证病人的安全现在的输液泵中通常包含了气泡检测这一项。超声波气泡检测技术已经比较成熟，并在医学上被广泛应用，本此毕业设计的任务就是完成输液管中气泡检测计的设计，从而完成输液过程的气泡的自动检测。 本文的主要工作是研究超声波气泡检测在STM32上的实现，该技术主要将超声波的散射衰减特性应用在输液泵上，即：超声波在介质中传播时，遇到声阻抗不同的界面产生散乱反射，从而会引起超声波的衰减。当输液管中没有气泡时，超声波反射系数很小，几乎没有衰减；有气泡时，由于空气和水的声阻抗相差较大，超声波会有很大的反射系数，此时超声波衰减严重。 本次毕业设计分为硬件部分和软件部分的设计：硬件部分设计了电路原理图、讨论了电路的可实现性以及PCB电路板的制作，其中电路设计主要包括超声波传感器驱动电路设计、超声波转化的电信号放大电路设计、充放电电路设计；软件部分设计包括对GPIO配置程序设计，时钟配置程序设计，中断配置程序设计等；并通过编程完成对STM32各端口输入输出配置和检测功能模块的实现，上述工作完成后用Uvision3对整个超声波检测系统进行调试；最后软硬件相结合后完成对超声波信号的产生、发射、接收、检测，最终实现了对气泡的检测。 本课题是在原有技术基础上做的一些探讨和新的检测方法的实现，具有一定的现实意义。 关键词：超声波，STM32，RC时间常数，Uvision3 ABSTRACT With the development of science and technology, medical devices continue to improve .And they have occupied an increasingly important position. It will adversely affect the patient when the air bubbles in the infusion tube go into patients bodies during the infusion .When the volume of bubble is greater than 5mL it can even make the patient to death . In order to ensure the patients safety the current infusion pumps typically include the item of bubble detection. Ultrasonic bubble detection technology is relatively mature and has been widely used in medicine field. The task of the graduation project is to complete the design of air bubbles detection and get to detect the air bubbles automatically in the process of infusion finally. This main work of the text is to study the realization of the ultrasonic bubble detection based on STM32. This technology is mainly used on infusion pumps and it applies the physical properties of ultrasonic: scattering and attenuation, this is, when the ultrasonic wave propagate in the medium, it will scatter and reflect with the meeting of the interface of different acoustic impedance which leads to fading .When theres not air bubbles in the infusion tube, the ultrasonic reflection coefficient is very small, almost no decay. On the contrary, because of the l