摘要
激光医学是当今发展最为迅速的医学领域之一。激光本身极好的方向性、单色性、相干性,以及激光与皮肤组织的作用的热效应、压强效应等,使其在治疗皮肤科疾病领域也有着极其广泛的应用。特别是在治疗色素性皮肤病方面,Q开关激光由于其被证实的“选择性光热作用”,使其既能有效地消除色素性皮肤病损,也能有效地避免对靶组织以外皮肤组织的伤害,因此已经被广泛地应用于该领域。
但是,我们在对Q开关单脉冲激光研究的过程中发现,我们可以通过提高泵浦速率来提高其单脉冲输出能量,并使脉冲宽度变窄,使输出峰值功率大大提高,从而提高治疗效果。但此方法从工程角度会加大激光介质和激光元器件损坏的危险性,从医学角度会加重由高功率激光在皮肤组织造成的二次压强效应——即所谓的“声瞬变”带来的声损伤。这使得提高输出能量和减小激光器件损坏危险、减少组织损伤成为矛盾。
从理论上讲,Q开关双脉冲甚至多脉冲治疗色素性皮肤病,可以将能量分两次或多次辐射出去,在脉冲宽度不变条件下,仍能保证和单脉冲一样的峰值功率,并同时减少了激光元器件损坏的危险性。但从医学角度Q开关双脉冲激光是否和单脉冲有相同的疗效?哪些因素会影响其治疗效果?本论文就围绕此方向展开研究,主要内容有:
1、在研究激光与皮肤组织作用机制的基础之上,对激光作用下皮肤的热效应进行了研究,并建立皮肤组织热传导的模型,进而分析激光对皮肤组织的热损伤和声损伤。
2、在研究Q开关单脉冲激光治疗色素性皮肤病损的基础之上,用动物实验对Q开关单脉冲、双脉冲激光治疗黑色文身的实际效果进行了比较研究,并在研究中通过数据说明能量密度、脉冲间隔对双脉冲激光治疗文身疗效的影响。最终通过比较实验发现,合适脉冲间隔的Q开关双脉冲激光与相同能量密度的Q开关单脉冲激光治疗文身的疗效相似,且在治疗过程中,双脉冲对皮肤的损伤明显小于单脉冲。
3、通过对Q开关单脉冲、双脉冲激光与皮肤组织的生物作用机制的研究,提出Q开关双脉冲激光治疗色素性皮肤病损能够在不提高激光峰值功率的前提下提高治疗色素性皮肤病损的效果且减轻损伤的原理,并进行了简单的数学分析。
Nowadays, laser medicine is one of the fastest development medical fields. Laser is used widely to cure the dermatosis because of its admirable directivity, monochromatic, coherence. Especially in the field of pigment skin disease therapy, Q-switched laser is used broadly because of the proved selective photothermolysis, which can eliminate the pigment in skin effectively and avoid the injury to the normal skin tissue effectively.
However, during the research of Q-switched single pulse, we find that we can increase the single pulse output energy by increasing the pumping rate, make the pulse duration narrower, and greatly improve the output power and the curative effect. But the high power laser can aggravate the second pressure effect what is called sound damage made by sound transient. And the method may lead laser medium and laser device damaged. Thus, improveing the laser energy contradicts the decrease of the tissue injury and the danger of laser device damaged.
In theory, using Q-switched double or multiple pulse laser therapy the pigment skin disease can make laser energy radiate twice or more. Thus, if the pulse duration is not changed, Q-switched double pulse laser can have the same output power as Q-switched single pulse laser, at the same time decrease the danger to make the laser device damaged. But is the curative effect of using Q-switched double pulse laser therapy the pigment skin disease similar as that of Q-switched single pulse? What factors can affect the curative effect? The paper made the research with the direct as the above said.
1 The interaction between laser and the skin tissue was studied. The calorific quality of skin was studied in laser therapy. A model for heat exchange in skin tissue was set up. With the model, we discussed the reason for the calorific or sound damage of the skin tissue by Q switched laser.
2 After the research of the basic knowledge of Q switched laser and skin pigmented disease, we compared the effect of the Q-switched single laser pulse with that of Q-switched double laser pulse to the black tattoo by the animal experiment. At the same time we researched the effect of energy density and pulse interval to the curative effect of the Q-switched double pulse through the data analysis. At last, we found that the curative effect of the Q-switched single pulse and double pulse was similar at the same energy density and that the skin injure of the Q-switched double pulse was less than the Q-switched single pulse.
3 On the basic of researching the biological active mechanism of the mutual action of the skin and the Q-switched single and double pulse, we put forward the principle that treating pigment skin diseases by the Q-switched double pulse can alleviate the skin injure on the premise of not improving the laser peak power. At last, we made the simple mathematic analysis.
引文
[1] Kilmer SL,LeeMS,Grevelink JM,et al,The Q-Switched Nd:YAG laser(1064nm) effectively treats tattoos: A controlled,dose-response study,Arch Dermatol,1993,129,971
[2] M L沃尔巴什特,刘普和.激光在医学和生物学中的应用[M].北京:科学出版社,1983
[3]朱菁.激光医学[M].上海:上海科学技术出版社,2003
[4] Markolf H Niemz,张镇西.激光与生物组织的相互作用[M].西安:西安交通大学出版社.1999
[5]金贞姬等.双脉冲激光对生物组织的热和声损伤机理研究[J].光电子·激光,2002,13(1):98-101
[6]秦梅香,朱菁.调Q激光去除文身[J].应用激光,2001,21(2):141-143
[7]叶志生等.Q开关红宝石激光治疗机的设计研究[J].光电子·激光,1999,10(6):557-559
[8]刘健航等.Q-开关红宝石、翠绿宝石激光去除文身等外源性色素的临床观察和实验研究[J].中国激光医学杂志,2001,10(3):156-160
[9] Jeffrey S Dover,etc. Pulse Width Dependence of Pigment Cell Damage at 694nm in Guinea Pig Skin[A].Proc SPIE.[C].1986,712:200-205
[10]邵中兴等.浅谈激光美容[J].世界医疗器械,1999,5(1):22
[11]赵福运.实用激光治疗学——激光在口腔、耳鼻喉科、皮肤科的应用[M].北京:北京医科大学中国协和医科大学联合出版社.1997
[12]虞启琏.医用激光仪器[M].天津:天津科学技术出版社,1986
[13]周炳琨等.激光原理[M].北京:国防工业出版社,1987
[14]黄卓正,李峻亨.现代激光医学[M].广西:广西科学技术出版社,1997
[15]朱菁,秦梅香等.Q开关Nd:YAG激光、倍频Nd:YAG激光、紫翠宝石激光治疗纹身的实验研究[J].应用激光,2001,12(6):407-411
[16]叶志生等.激光在皮肤病学应用中的最新进展[J].光电子·激光,2000,11(6):677-680
[17]赵友全,李立勇等.脉冲激光在医学中的光热效应分析[J].中华物理医学与康复杂志,2004,26(2):114-116
[18]刘春利,苑凯华等.Q开关激光去除皮肤细胞色素机理探讨[J].中华医学美容杂志,1999,5(1):4-6
[19]谢治,张宁等.激光祛除文身的进展[J].中国激光医学杂志,2003,12(3):192-194
[20]冯海涛,董蕙.脉冲激光在治疗皮肤色素性病变中的应用[J].实用临床医学,2005,6(1):129-130
[21]朱健,张树标等.Q开关Nd:YAG激光治疗皮肤色素损害的临床应用和动物实验[J].应用激光,2005,25(5):351-354
[22] Martin J C etc.Time Constants in Thermal Laser Mediciene[J].Lasers in Surgery and Medicine 2005,25(5):351-354
[23]蓝信锯.激光技术[M].武汉:华中理工大学出版社,1995
[24] W.克希奈尔.固体激光工程[M].北京:科学出版社,1983
[25]刘恩全等.激光生物动力学[M].山东:济南出版社,1992
[26]李文维等.调Q红宝石激光去除文身的临床应用[J].中国激光医学杂志,1998,7(3):10-11
[27]周展超,郑家润.脉冲激光在皮肤病中的应用[J].国外医学皮肤性病学分册,2002,28(3):145-147
[28]孙林潮,高天文等.皮肤色素性病变的激光治疗[J].中国美容医学杂志,2003,12(5):550-552