非稳态吸气条件下理想人体口喉模型内的颗粒物沉积实验研究

 2022-06-23 08:06

论文总字数:22720字

摘 要

本文首先叙述了实验平台的各个部分,并重点介绍了此实验平台是如何实现拟合任意呼吸波形的,包括所使用的到的软件和硬件部分。之后本文进行了在不同平均流量(15-60L/min)sin波形下和不同颗粒物粒径下(2μm-10μm)呼吸道的沉积实验,测量出了不同Stokes下的沉积率。并与前人研究进行了对比,重点关注了稳态和非稳态吸气、包括颗粒物粒径和流量对颗粒物沉积率和沉积特性的影响。

主要结论为:可吸入颗粒物在理想口喉模型内的沉积随Stokes数增加而呈近似指数式的上升;同时,Stokes数相同条件下,sin吸气波形比稳态时的沉积率高20%左右。

关键词:sin呼吸波形;可吸入颗粒物;沉积率

Experimental study of particle deposition in ideal human airway under unsteady inhalation condition

03014333 Rui Ma

Supervised by Xiaole Chen

Abstract:In recent years, the effect that inhalable particles caused on people’s health has aroused widespread concerns , and more and more researchers have focused on it. One of these studies is about the deposition rate and depositional patterns of these inhalable particles in the respiratory tract. Under current techniques, although numerical simulation can effectively simulate the deposition characteristics of particles in various inspiratory state (such as real breathing state, smoking state, etc.), relevant evidences on experiments are absence, because most of the similar experiments are still in the steady state. Thus, in order to provide reliable evidence for numerical simulation, it is necessary to carry out the experiment of particle deposition under unsteady state.

Firstly, in this paper, various parts of the experimental platform are illustrated, particularly the device that realizes any respiratory waveform, including principles, software and hardware that this device used. After that, the deposition experiments t under different average flow (15-60L/min) sin and particle size (2μm-10μm) were carried out, and the deposition rates under different Stokes are measured. In addition, comparisons with previous studies are made, focusing on different deposition efficiency and patterns caused breathing waves, flow rate and particle size.

The main conclusions are: The deposition of inhalable particles in the ideal throat model increases approximately exponentially with the increase of Stokes number. At the same time, under the same Stokes number, deposition efficiency in the unsteady state is about 20% higher than that in the steady state.

Key words: sin breathing wave; inhalable particles; deposition efficiency

目 录

1绪论 1

1.1研究背景 1

1.2国内外研究进展 2

1.3研究内容和技术路线 2

1.4 研究意义 4

1.5本章小结 4

2实验平台的搭建及任意波形的实现 5

2.1 实验平台 5

2.2基本原理与整体结构 6

2.2.1 基本原理 6

2.2.2 整体结构 7

2.3 硬件设计 7

2.3.1 阀门的设计 7

2.3.2 流量计的选型 8

2.3.3下位机的设计与选择 8

2.3.4 上位机与下位机的通信 8

2.4 软件设置及编程 8

2.4.1 下位机接收流量计的模拟量信号 8

2.4.2 下位机控制伺服电机的设置以及编程 8

2.4.3 PLC与PC串口通信的部分 9

2.4.4 PC端中串口的设置及代码 10

2.4.5 PID控制中控制器在PC端的实现 10

2.5 部分控制效果图 11

2.6本章小结 12

3实验流程 14

3.1实验准备 14

3.2 超声清洗呼吸道 14

3.3真空抽滤 14

3.4真空干燥 15

3.5称量滤膜 15

3.6 注意事项 15

3.7本章小结 16

4实验结果分析 17

4.1同一粒径不同流量下呼吸道沉积形式分析 17

4.2 同一流量不同粒径下呼吸道沉积形式分析 18

4.3 沉积率的计算与分析 19

4.4 误差分析 21

4.5 课题展望 21

致谢 22

参考文献 23

1、绪论

1.1研究背景

工业革命以来,工业发展迅速,燃料燃烧剧增。燃料燃烧导致大量颗粒物的释放,造成了严重的颗粒物污染[1]。中国就是世界上颗粒物污染最严重的国家之一,尤其是在我的故乡山西,每年冬季来临以后,空气中不仅充满着雾霾,有时候甚至弥漫着黄色的空气污染物。当这种天气出现以后,大量的可被人体吸入的颗粒物会随着人类的呼吸进入人体,从而破坏人的呼吸系统。

可吸入颗粒物是指当量直径小于等于10微米的颗粒物,虽然其当量直径比较小,但其表面积大,并携带有大量的有害物质[2]。而且空气中的此种颗粒物组成复杂并且成分不固定,其成分大致包括有机成分、水溶性成分和水不溶性成分,其中有机成分最多,如可溶于苯的有机物如多环芳烃等,多环芳烃是导致人体癌症重要来源之一。若这些颗粒物进入人体呼吸道,能被吸入人的支气管和肺泡中并沉积下来,引起或加重呼吸系统的疾病。并且颗粒越细小对人体的危害越大,某些超细颗粒物甚至可以进入血液循环,会造成人体广泛的损伤,涉及到呼吸系统、心脏及血液系统、免疫系统和内分泌系统等,如慢性阻塞性肺病就是一种由可吸入颗粒物导致的呼吸道疾病[1]

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