多波形输出的等离子手术系统开发

发布时间：2018-04-09 16:34

本文选题：低温等离子体　切入点：开关电源　出处：《杭州电子科技大学》2017年硕士论文

【摘要】：低温等离子手术设备通过高频交流电压电离生理盐水来产生等离子体。而等离子体的强活性和高频电流的热效应面对生物组织时,能够达到消融、切割、凝血等多种手术功能。低温等离子手术具有操作方法简便、操作温度低、手术创伤小、术后恢复快、治愈率高等诸多优点,在微创手术中有着突出的表现。在最近的十几年里,随着医疗水平的快速发展,微创手术在各个科室得到了越来越广泛的应用,对低温等离子手术设备的需求也在不断增长。但目前的消融设备体积大、功能少,给医生带来诸多不便。本文致力于研发一台小型化的多功能低温等离子手术设备。低温等离子手术设备输出不同频率、不同幅度的交流电压会产生不同状态的等离子体,针对不同部位的人体组织能达到不同手术效果。通常会通过调节交流信号的电压幅度来完成对不同细胞组织的手术,利用不同频率的交流信号来达到不同的手术效果。此外,连续与断续的高频交流电压也能实现不同的手术效果。基于这一生物理论,采用开关电源技术设计一台集成多个工作频段、多种输出波形、输出电压可调的高频方波逆变器。高频逆变器的设计往往会涉及到变压器,受变压器特性限制,不同逆变频率需要匹配不同的绕组匝数。多个交流频率输出的逆变器通常会采用多个逆变回路来实现,但这会导致设备的体积变大和成本增加。本文利用变压器匝数与伏秒积的线性正比关系,根据输出频率的设置及实时输出电压来调节逆变驱动信号占空比,用同一回路完成不同频率的逆变。采用可编程逻辑器件CPLD代替传统的模拟集成芯片来产生逆变驱动信号,使控制更加灵活、可靠。由此,可在不增加设备体积的基础上可提供多种输出波形用于手术。本文以等离子体及高频电流对生物组织的消融效应为根本原理,以开关电源为技术核心,开发了一台多波形输出的低温等离子手术系统,并获得以下成果:(1)输出断续或连续的100KHz或310KHz的方波信号,配合不同手术刀头实现多种手术功能。(2)输出电压在8V~148V内可调,以适应不同部位的生物组织。(3)具有短路保护,确保手术过程中安全性。(4)提高了系统功率,实现系统的稳定性。
[Abstract]:Low-temperature plasma surgery equipment ionization of saline by high-frequency AC voltage to produce plasma.The strong activity of plasma and the heat effect of high frequency current can achieve many kinds of surgical functions, such as ablation, cutting, coagulation and so on.Low temperature plasma surgery has many advantages, such as simple operation method, low operating temperature, small surgical trauma, quick postoperative recovery, high cure rate and so on, so it has outstanding performance in minimally invasive surgery.In the last decade, with the rapid development of medical treatment, minimally invasive surgery has been more and more widely used in various departments, and the demand for hypothermia plasma surgery equipment is also increasing.However, the current ablation equipment is large in size and less in function, which brings a lot of inconvenience to doctors.This paper is committed to the development of a miniaturized multi-functional low-temperature plasma surgery equipment.The low temperature plasma surgery equipment outputs different frequency, the different amplitude AC voltage will produce the different state plasma, according to the different position human body tissue can achieve the different surgical effect.The operation of different cell tissues is usually accomplished by adjusting the voltage amplitude of AC signals, and different surgical effects are achieved by using different frequency AC signals.In addition, continuous and intermittent high-frequency AC voltage can also achieve different surgical results.Based on this biological theory, a high frequency square wave inverter with multiple working frequency bands, multiple output waveforms and adjustable output voltage is designed by using switching power supply technology.The design of high frequency inverter often involves transformer. Due to the limitation of transformer characteristic, different inverter frequency needs to match different winding turns.Inverters with multiple AC frequency outputs are usually implemented with multiple inverter circuits, but this will result in larger volume and higher cost of the equipment.In this paper, the linear proportional relation between transformer turns and volt second product is used to adjust the duty cycle of inverter driving signal according to the setting of output frequency and the real time output voltage, and the inverter with different frequency is completed by the same loop.The programmable logic device (CPLD) is used instead of the traditional analog integrated chip to generate the inverter driving signal, which makes the control more flexible and reliable.Thus, a variety of output waveforms can be provided for surgery without increasing the volume of the equipment.Based on the ablation effect of plasma and high frequency current on biological tissue, a low temperature plasma surgery system with multi-waveform output is developed in this paper, which is based on switching power supply.The following results are obtained: 1) output intermittent or continuous square wave signals of 100KHz or 310KHz, combined with different scalpel heads to achieve multiple surgical functions. The output voltage can be adjusted within the 8V~148V to adapt to the short circuit protection of different parts of biological tissue.Ensure the safety during the operation. 4) improve the power of the system and realize the stability of the system.
【学位授予单位】：杭州电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R61;R319

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