【摘要】：光熱治療是一種以光和熱為主要物理因子的理療方法，通過特定波長的光照射人體組織產(chǎn)生的光化學(xué)效應(yīng)和熱效應(yīng)來治療皮膚疾病、婦科疾病以及淺表部位的癌癥等疾病。光熱治療具有無創(chuàng)、副作用小的優(yōu)點(diǎn)，而且可以和其他治療方法相結(jié)合，在臨床上得到了廣泛的應(yīng)用。光熱治療中的熱效應(yīng)會引起組織溫升，溫度可以反映了組織對光的吸收情況。對于某些疾病而言，只有在一定溫度閾值范圍之內(nèi)，，光熱治療才能達(dá)到預(yù)期的治療作用。因此溫度直接反應(yīng)了光熱治療的效果，是臨床治療中需要控制的參數(shù)�？刂平M織的溫升可以引導(dǎo)光熱治療，使其更加安全有效，但是一般的光熱治療儀器都缺少對組織溫度控制的功能。 為了實(shí)時(shí)監(jiān)測光熱治療過程中照射部位組織的溫度，本文基于ARM920T架構(gòu)的S3C2440和Linux嵌入式操作系統(tǒng)設(shè)計(jì)了溫度可控的LED光熱治療系統(tǒng)。大功率LED的性能隨著半導(dǎo)體技術(shù)的發(fā)展得到了很大進(jìn)步，是光熱治療輻射光源的理想選擇。系統(tǒng)硬件由LED陣列光源驅(qū)動部分、溫度采集部分、微處理器部分以及人機(jī)交互部分組成。針對大功率LED陣列的特性和發(fā)光要求，以LM3406芯片為核心的恒流驅(qū)動電路驅(qū)動電流達(dá)到了1.2A并且具有PWM調(diào)光功能；紅外測溫模塊TN901采用熱電堆傳感器采集目標(biāo)溫度，通過SPI接口將溫度信號傳輸給微處理器S3C2440；S3C2440外圍電路包括的串口、USB接口、JTAG接口以及液晶觸摸屏模塊實(shí)現(xiàn)系統(tǒng)的通信、調(diào)試、數(shù)據(jù)傳輸和人機(jī)交互。系統(tǒng)軟件設(shè)計(jì)分為驅(qū)動程序和應(yīng)用軟件GUI兩部分，驅(qū)動程序根據(jù)硬件設(shè)備的需要編寫，應(yīng)用軟件在QtCreator集成開發(fā)環(huán)境下設(shè)計(jì)。用戶界面分為光熱治療參數(shù)設(shè)置界面、PID控制界面和溫度曲線繪制界面。本文根據(jù)光熱治療中人體組織對溫度控制的要求，對傳統(tǒng)的PID算法進(jìn)行了改進(jìn)，加入了積分分離環(huán)節(jié)。由目標(biāo)溫度和TN901采集的組織溫度通過積分分離PID算法計(jì)算PWM信號的占空比，進(jìn)而調(diào)節(jié)LED輸出的光功率密度，實(shí)現(xiàn)了組織溫度的精確控制。 完成LED光熱治療系統(tǒng)設(shè)計(jì)后，通過萬用表和激光能量計(jì)測量了不同PWM占空比下的LED工作電流和輸出光功率密度，測試結(jié)果表明PWM信號可以線性調(diào)節(jié)這兩個(gè)參數(shù)。選用新鮮的豬皮作為離體組織樣品進(jìn)行光熱治療的模擬實(shí)驗(yàn)，對系統(tǒng)溫度控制性能進(jìn)行測試，實(shí)驗(yàn)結(jié)果顯示系統(tǒng)的溫度控制效果好、品質(zhì)高，最大過沖量不超過1℃，穩(wěn)態(tài)誤差為±0.5℃，能夠滿足光熱治療對溫度控制的要求。本文還對紅光緩解肌肉疲勞進(jìn)行了初步的實(shí)驗(yàn)研究，分析了志愿者實(shí)驗(yàn)中采集的指力信號，并對實(shí)驗(yàn)提出相關(guān)的改進(jìn)方法，為以后進(jìn)一步深入研究奠定了基礎(chǔ)。
[Abstract]:Photothermal therapy is a physiotherapy method with light and heat as the main physical factors. The photochemical and thermal effects of light irradiation on human tissues are used to treat skin diseases, gynecological diseases and superficial cancer. Photothermal therapy has the advantages of noninvasive, less side effects, and can be combined with other treatment methods, and has been widely used in clinical. The thermal effect of photothermal therapy can cause tissue temperature to rise, which can reflect the absorption of light. For some diseases, only within a certain temperature threshold range, photothermal therapy can achieve the desired therapeutic effect. Therefore, temperature directly reflects the effect of photothermal therapy and is a parameter to be controlled in clinical treatment. Controlling tissue temperature rise can lead to photothermal therapy and make it safer and more effective, but the common photothermal therapy instruments lack the function of tissue temperature control. In order to monitor the temperature of irradiated tissue in the course of photothermal therapy in real time, a LED photothermal therapy system with controllable temperature was designed based on S3C2440 and Linux embedded operating system based on ARM920T architecture. With the development of semiconductor technology, the performance of high power LED has been greatly improved, and it is the ideal choice of radiation source for photothermal therapy. The hardware of the system is composed of LED array light source driving part, temperature acquisition part, microprocessor part and man-machine interaction part. According to the characteristics and luminescence requirements of high power LED array, the driving current of the constant current drive circuit with LM3406 chip as the core is 1.2A and has the function of PWM dimming. The infrared temperature measurement module TN901 uses thermoelectric reactor sensor to collect the target temperature and transmits the temperature signal to microprocessor S3C2440 through SPI interface. The peripheral circuit of S3C2440 includes serial port, USB interface, JTAG interface and LCD touch screen module to realize system communication, debugging, data transmission and man-machine interaction. The software design of the system is divided into two parts: driver and application software GUI. The driver is written according to the need of hardware equipment. The application software is designed under the environment of QtCreator integrated development. The user interface is divided into photothermal therapy parameter setting interface, PID control interface and temperature curve drawing interface. According to the requirement of temperature control in human tissue during photothermal therapy, the traditional PID algorithm is improved and integral separation is added. The duty cycle of PWM signal is calculated by the integral separation PID algorithm from the target temperature and the tissue temperature collected by TN901, and then the optical power density of LED output is adjusted to realize the accurate control of the tissue temperature. After the design of LED photothermal therapy system, the working current and output optical power density of LED under different PWM duty cycle are measured by multimeter and laser energy meter. The results show that PWM signal can adjust these two parameters linearly. Using fresh pig skin as the sample of photothermal treatment in vitro, the temperature control performance of the system was tested. The results showed that the temperature control effect of the system was good, the quality of the system was high, and the maximum impulse was less than 1 鈩

本文編號：2357544