【摘要】：激光具有高單色性、高方向性、高亮度性和良好的相干性等特點(diǎn)。激光問(wèn)世以來(lái)，已被廣泛應(yīng)用于臨床治療。其中大部分的應(yīng)用都涉及熱效應(yīng)，如激光高熱療法、凝結(jié)以及激光外科。為了確保治療安全和提高效率，開(kāi)展針對(duì)生物組織的光熱效應(yīng)與熱損傷的研究就顯得十分必要。 本文首先基于雙相位滯后模型，根據(jù)激光在生物組織內(nèi)部熱傳導(dǎo)的實(shí)際情況，對(duì)激光照射下生物組織中非傅里葉傳熱現(xiàn)象進(jìn)行了數(shù)值模擬。 其次對(duì)連續(xù)He-Ne激光照射下大鼠皮膚組織溫度隨時(shí)間變化的規(guī)律進(jìn)行了實(shí)驗(yàn)研究。實(shí)驗(yàn)采用將熱電偶從激光照射面的對(duì)面插入，通過(guò)改變激光照射時(shí)間、功率等相關(guān)參數(shù)，按照一定的采樣速度采集每一次信號(hào)，記錄下該位置處組織溫度隨時(shí)間變化的溫度數(shù)據(jù)。 本文采用數(shù)值模擬中的有限差分法，，對(duì)雙相位滯后模型進(jìn)行數(shù)值模擬。通過(guò)改變?chǔ)觃T和τ_q的取值，將雙相位滯后模型、傅里葉模型和雙曲熱波模型的數(shù)值模擬結(jié)果進(jìn)行比較和分析。模擬結(jié)果表明：當(dāng)τ_T和τ_q的取值相等并且都非常小時(shí)，雙相位滯后模型的數(shù)值模擬結(jié)果和傅里葉模型的數(shù)值模擬結(jié)果相同。否則，即使τ_T=τq，DPL模型描述的熱傳導(dǎo)也不同于傳統(tǒng)傅里葉熱模型。在激光照射生物組織前期，τ_q對(duì)溫度的影響更大些，激光停止照射后，τ_T對(duì)溫度的影響更大些。當(dāng)τ_q固定在16s，τ_T變化時(shí)，在取消激光照射后，生物組織溫度變化會(huì)隨著τ_T取值增大而增大；當(dāng)τ_T固定在0.05s，τ_q變化時(shí)，τ_q的取值越大，組織的溫度越高。 對(duì)連續(xù)He-Ne激光照射下大鼠皮膚組織的溫度隨時(shí)間變化的規(guī)律進(jìn)行了實(shí)驗(yàn)研究，實(shí)驗(yàn)采用He-Ne激光器照射大鼠組織表面和皮下組織1mm處，通過(guò)紅外輻射測(cè)溫儀和熱電偶探針來(lái)探測(cè)被照組織的溫度，通過(guò)改變激光照射時(shí)間和功率，研究被照組織溫度隨時(shí)間的變化情況。實(shí)驗(yàn)結(jié)果表明：當(dāng)激光開(kāi)始照射時(shí)，大鼠組織表面和皮下組織1mm處的溫度在照射期間會(huì)隨著照射時(shí)間的增加而迅速增加，當(dāng)激光照射停止后，大鼠組織表面溫度快速下降，而大鼠皮下組織1mm處溫度緩慢下降。當(dāng)用相同激光能量照射大鼠組織表面時(shí)，隨著功率的增加，組織表面溫度也相應(yīng)增加，組織表面溫度出現(xiàn)波動(dòng)現(xiàn)象，并在25s后組織表面溫度趨于平穩(wěn)。組織表面溫升隨著激光照射中心的徑向距離的增加而減小。
[Abstract]:Laser has the characteristics of high monochromatic, high directivity, high brightness and good coherence. Since the advent of laser, it has been widely used in clinical treatment. Most of these applications involve thermal effects, such as laser hyperthermia, coagulation, and laser surgery. In order to ensure the safety of treatment and improve efficiency, it is necessary to study the photothermal effects and thermal damage of biological tissues. In this paper, based on the two-phase hysteresis model, the non-Fourier heat transfer phenomenon of biological tissue under laser irradiation is numerically simulated according to the actual condition of laser heat conduction in biological tissue. Secondly, the changes of skin temperature with time under continuous He-Ne laser irradiation in rats were studied experimentally. In the experiment, the thermocouple is inserted from the opposite side of the laser irradiation surface. By changing the laser irradiation time, power and other related parameters, each signal is collected at a certain sampling rate. Record the temperature data of tissue temperature over time at this position. In this paper, the finite difference method in numerical simulation is used to simulate the double phase lag model. By changing the values of 蟿 T and 蟿 Q, the numerical simulation results of biphase lag model, Fourier model and hyperbolic heat wave model are compared and analyzed. The simulation results show that when the values of 蟿 T and 蟿 Q are equal and very small, the numerical simulation results of the two-phase delay model are the same as those of the Fourier model. Otherwise, the heat conduction described by the 蟿 T = 蟿 QO DPL model is different from that of the traditional Fourier model. In the early stage of laser irradiation to biological tissue, 蟿 _ Q has a greater effect on temperature, and 蟿 _ T has more effect on temperature after laser irradiation is stopped. When T _ Q is fixed at 16 s and 蟿 _ T is changed, when laser irradiation is cancelled, the temperature change of biological tissue will increase with the increase of 蟿 _ T value; when 蟿 _ T is fixed at 0.05s and 蟿 _ S _ Q changes, the higher the 蟿 _ Q value is, the higher the tissue temperature will be. The effect of continuous He-Ne laser irradiation on the temperature of rat skin tissue was studied. The He-Ne laser was used to irradiate the surface of the rat tissue and the 1mm of the subcutaneous tissue. Infrared radiation thermometer and thermocouple probe are used to detect the temperature of irradiated tissue. By changing the time and power of laser irradiation, the variation of the temperature of irradiated tissue with time is studied. The results showed that the temperature of 1mm in tissue and subcutaneous tissue of rats increased rapidly with the increase of irradiation time when laser irradiation was started, and the temperature of tissue surface decreased rapidly after laser irradiation stopped. However, the temperature of 1mm in rat subcutaneous tissue decreased slowly. When the tissue surface was irradiated with the same laser energy, the tissue surface temperature increased with the increase of power, and the temperature of the tissue surface fluctuated, and the temperature of the tissue surface tended to be stable after 25 seconds. The temperature rise of the tissue surface decreases with the increase of the radial distance of the laser irradiation center.
【學(xué)位授予單位】：河南科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2012
【分類(lèi)號(hào)】：R318.51

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本文編號(hào)：2137017