超声内镜环扫成像设备前端驱动系统设计

发布时间：2018-04-09 17:41

本文选题：超声内镜　切入点：单片机　出处：《天津大学》2013年硕士论文

【摘要】：前端驱动系统是超声内镜成像设备的重要组成部分。超声内镜成像设备通过超声换能器进行组织特征探测，利用接收放大电路和数字处理电路实现回波信号的接收、调理、变换，最终形成组织的超声断层图像。超声内镜成像设备的前端驱动系统是驱动超声换能器完成环扫成像的关键部件，其性能对超声内镜成像质量具有重要的影响。为开发具有自主知识产权的超声内镜产品，打破该领域的国外垄断地位，本文根据超声内镜产品功能需求，设计了超声内镜成像设备的前端驱动系统。本文的主要工作如下： 1、根据超声内镜前端驱动系统的功能和功能需求，完成各个功能模块的功能划分和设计方案制定； 2、利用输出可调型开关稳压电源芯片的自调节功能，设计了自反馈电路，配合单片机软件D/A调节，完成了电机驱动的设计，实现了对脉冲宽度调制（PMW：Pulse Width Modulation）调速电机的高精度控制。该电机驱动系统具有精度高、响应快、可靠性高以及很好的通用性和可移植性等优点。驱动理论反馈响应时间为20μs，电机在设计速度范围（300-1500r/min）和变化负载条件下测试，最大转速误差为2r/min，平均不稳定度低达0.11%。该驱动能够确保负载变化下电机速度平稳，保证成像质量，提高医生的诊断效率和准确率。 3、利用高压产生模块，结合单片机D/A和A/D组成的反馈系统，完成了高压驱动的设计，实现了换能器激励高压的精准控制输出。该高压驱动具有精度高、可靠性高等优点。能可控精准输出0-200V的电压，最大电压误差为0.2V。该高压驱动增大了换能器的激励电压，，提升了发射超声波的功率，并且输出电压稳定，有助于提高图像的信噪比； 4、使用I2C通讯实现了对探头频率型号和阻抗的读取识别； 5、使用RS-485接口实现了前端驱动单元与上位机的通讯功能； 6、设计了系统运行状态监测模块，可自动发现故障并采取相应处理措施，保证系统运行安全可靠，最大程度保证使用者的人身安全与设备安全。
[Abstract]:The front drive system is an important part of endoscopic ultrasound imaging equipment. The organization characteristics of endoscopic ultrasound imaging equipment detection by using ultrasonic transducer, receiving and amplifying circuit and digital processing circuit for receiving, signal conditioning, transformation, and ultimately the formation of 2D ultrasonic image of the organization. The front endoscopic ultrasound imaging equipment driving system is a key component of ultrasonic drive complete circular scanning imaging transducer, its performance has an important influence on the quality of endoscopic ultrasound imaging. Endoscopic ultrasonography for developing products with independent intellectual property rights, to break the foreign monopoly in this field, according to the functional requirements of endoscopic ultrasound products, design the front-end endoscopic ultrasound imaging equipment driving system.
The main work of this article is as follows:
1, according to the functional and functional requirements of the endoscope front end drive system, the functional division of each functional module and the design scheme are completed.
2, self regulating function using the adjustable output switching power supply chip, designed a self feedback circuit with single-chip D/A control software, completed the design of motor drive, the pulse width modulation (PMW:Pulse Width Modulation) high precision speed motor control. The motor drive system has high accuracy and fast response. High reliability and good versatility and portability advantages. The driving theory of feedback response time is 20 s, in the design of motor speed range (300-1500r/min) and the change of the load under the condition of test, the maximum speed error is 2r/min, the average degree of instability as low as 0.11%., the driver can ensure the load change under the motor speed is steady, to ensure the imaging quality, improve diagnosis efficiency and accuracy.
3, using high voltage generating module, feedback system with single chip D/A and A/D, completed the design of the high voltage drive, to achieve the precise control of the output voltage transducer. The excitation voltage drive with high precision, high reliability. The voltage controllable precision output 0-200V, the maximum voltage error is 0.2V. the high voltage driving increases the incentive voltage transducer, enhance the transmit power of ultrasonic wave, and the output voltage stability, helps to improve the signal-to-noise ratio of the image;
4, using I2C communication to realize the reading and recognition of the type and impedance of the probe frequency.
5, the communication function of the front end drive unit and the upper computer is realized by using the RS-485 interface.
6, we design the monitoring module of the system running state, which can automatically detect faults and take corresponding measures to ensure the safe and reliable operation of the system, and ensure the safety and safety of the users to the greatest extent.

【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：O426.9

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