摘 要

随着生物医学的不断发展，“人工心脏”在心脏外科领域成为了极为关注的焦点，心脏泵作为人工心脏的驱动源，更是研究的重点课题。人工心脏泵主要分为轴流式血泵、离心式血泵和混合式血泵。其中轴流式血泵因其结构紧凑、重量轻、更容易移植等优势，得到了广泛的研究和应用，轴流式血泵作为一种左心室辅助装置，对于心脏病患者具有重要的意义。

本文是以武汉理工大学设计研发的轴流式血泵体外循环试验装置为基础，该循环装置中包括储液罐、血泵入口压力计、血泵、血泵出口压力计、流量计、阻尼阀和10mmPVC导管。根据设计要求，设计了进出口压力计和流量计传感器的输出信号转换电路，利用单片机的ADC采集传感器信号并上传到上位机；设计了血泵电机转速控制和测量电路，分别利用单片机的DAC实现电机转速控制和TIM实现转速测量；设计了TTL转RS485电路，实现了单片机的串口与阻尼阀的RS485接口通信，以此达到了控制阻尼阀开度的目的；利用Labview绘制压力和流量曲线，绘制不同血泵电机转速下流量与进出口压力差的Q-H曲线；将测量数据保存到EXCEL文本中；对测试系统进行了误差分析；设计并进行了轴流式血泵体外循环测试实验，得到实验数据。

该设计的测试结果表明该轴流式血泵体外循环测试系统能够能够达到设计要求。为后续的水力特性实验、分析仿真数据和实验结果，为进一步设计和优化血泵、进行动物实验及临床应用奠定基础。

关键词：轴流式血泵，STM32，Labview

ABSTRACT

With the continuous development of biomedical, "artificial heart" has become the focus of great concern in the field of cardiac surgery . heart pump, as a driving source of artificial heart, is the focus of research topics. Artificial heart pumps are mainly divided into axial blood pump, centrifugal blood pump and mixed blood pump. Axial flow pump is a kind of left ventricular auxiliaries, which is of great significance for patients with heart disease because of its compact structure, light weight, easier to transplant and so on. It has been widely studied and applied.

This paper is based on an axial blood pump extracorporeal circulation device which has been designed by WHUT.This device consists of the liquid reservoir,inlet pressure sensor, axial blood pump,export pressure sensor，flow sensor，damping valve and some 10mm PVC catheter.According to the design requirements,I have designed the output signal conversion circuit of the inlet and export pressure and the flow meter sensor so that the ADC of the STM32 MCU could sample and convert the analog signal into a digital signal and then upload to host computer.I have designed the rotating speed controlling and measuring circuit of the blood pump for the status of the circulation system.The DAC of the MCU can output the analog volatile signal to control and the TIM can measure the the rotating speed of blood pump. I designed a TTL to RS485 circuit for the communication of the MCU and the damping valve in order that the MCU could control the opening degree of the damping valve.I have programed the host computer with the Labview to receive the data uploaded from the MCU.Accroding to these data,the host computer can draw the curves of the three senors. Moreover,the flow meter Q and the pressure difference H will be drawn in one coordinate system as the Q-H curves.For further reseach,all data measured will be saved in an EXECL document.At last,I experimented and

recorded some data.

The test results show that the axial flow pump blood bypass test system can meet the design requirements.The paper lays the foundation of hydraulic characteristics of the experiment, analysis of simulation data and experimental results, the further design and optimization of blood pumps, animal experiments and clinical application .

KEY WORD:axial flow blood pump，STM32，Labview

目录

1绪论 1

1.1研究的目的及意义 1

1.2国内外研究现状 1

1.2.1国外研究现状 2

1.2.2国内研究现状 3

1.3目前存在的问题 4

1.4研究内容 4

2方案论证 6

2.1方案对比 6

2.2方案设计 6

3硬件电路设计 10

3.1信号转换电路 10

3.1.1压力计测试电路 10

3.1.2流量计测试电路 11

3.2 控制电路 12

3.2.1 电机驱动电路 12

3.2.2 阻尼阀控制电路 13

3.3 STM32最小系统电路 14

3.4 USB转串口电路 15

3.5 供电电路 16

4.软件设计 17

4.1单片机程序设计 17

4.1.1定时器定时10ms 17

4.1.2压力、流量读取程序 18

4.1.3电机转速控制和测量程序 19

4.1.4 阻尼阀通信程序 20

4.1.5单片机与上位机通信程序 21

4.2上位机程序设计 22

4.2.1串口数据读取 23

4.2.2数据显示 24

4.2.3转速与阻尼阀控制程序 26

4.2.4测量数据保存程序 27

5误差分析 28

5.1 信号转换误差 28

5.2 ADC转换误差 30

5.3 DAC输出误差 31

5.4 放大器放大倍数误差 32

6调试结果及轴流式血泵体外循环测试实验 34

6.1调试结果 34

6.2轴流式血泵体外循环测试实验 36

7总结和展望 38

参考文献 39

致谢 41

附录A：硬件电路图

附录B：元器件清单

附录C：程序清单

1绪论

1.1研究的目的及意义

流行病学资料显示，目前全球心衰患者已高达 2250 万人，且正以每年200 万人的速度逐年递增^[1]。可供心脏移植的供体严重不足，以美国为例, 每年大约新增40000名心脏病患者,其中仅有2300余人能接受心脏移植手术^[2],大部分病人需要循环辅助设备来维持生命，直到寻找到合适的心脏供体。仅仅依靠心脏移植显然已经不能满足心衰患者的治疗要求，心脏移植仍然是治疗心衰终末期患者唯一永久有效的办法，心室辅助装置（Wentricular Assitant Device）成为治疗心衰最后的希望。人工心脏泵是治疗终末期心脏衰竭最有效的心室辅助装置之一，在心脏术后心肌功能恢复、心脏移植过渡期间和永久性心脏替代方面发挥了重大作用，显著提高了终末期心衰患者的生活质量和生存年限^[3]。在过去 20 年中，血泵作为一种前景广阔的左心室辅助装置得到世界各地医师和患者的广泛接受，许多研究机构都开发出自己的产品^[4]。

人工心脏泵主要分为轴流式血泵、离心式血泵和混合式血泵。其中轴流式血泵因其结构紧凑、重量轻、更容易移植等优势，得到了广泛的研究和应用，轴流式血泵作为一种左心室辅助装置，对于心脏病患者尤其是等待移植的重症患者，具有重要的意义^[5]。