激光减胎的机理及系统研究

发布时间：2018-03-13 21:52

本文选题：脉冲激光　切入点：减胎　出处：《浙江大学》2014年硕士论文　论文类型：学位论文

【摘要】：近年来,随着辅助生育技术的发展,生殖科学在临床实践中获得很大的成功。但是由于诱导排卵药物以及辅助生殖技术的广泛使用,在为许多不孕夫妇带来希望的同时亦导致多胎妊娠发生率逐年提高。多胎妊娠会显著增加孕产妇及胎儿的风险。为提高多胎妊娠中孕妇分娩的成功率,因此对于三胎以上的多胎妊娠,应及时进行减胎术,术后保留1-2个健康存活的胚胎,既可达到生育目的又可消除多胎妊娠导致的不良后果。目前常用的减胎方法需采用穿刺针机械刺入孕囊和胎心,会引起胎动,影响机械穿刺的精准度,而且这几种方法均存在易感染、操作费时、手术难度高的问题。随着激光技术的发展与日渐成熟,利用高能量脉冲激光对胚胎进行减灭成为一种很有前景的减胎手术方法。因此,我们提出了一种全新的减胎手术的方法,即采用1064nm的脉冲激光直接聚焦于孕囊内的胚胎内部,通过激光作用于胚胎心脏部位产生的光学击穿效应,对胚胎心脏造成损伤,使胚胎快速死亡,达到减胎的目的。该方法避免了机械针穿刺,且激光脉冲作用的时间非常短,为纳秒量级,避免了胚胎被作用时的剧烈胎动及热效应,很大程度上降低了减胎手术的难度,提高了手术的精准度,在辅助生殖领域具有很好的应用前景。本文首先基于激光与生物组织相互作用的机理和激光在水中及生物组织中的光学特性,对激光减胎进行理论分析,阐述了激光减胎过程中发生的光学击穿效应的基本原理；其次,建立激光减胎的理论模型,从冲击波、空化和热效应等方面验证激光减胎方法的安全性；再次,使用牛肌肉组织和猪脂肪组织进行生物实验研究,得出激光参数与损伤尺寸的关系,优化实验中所使用的激光参数；利用高速相机和水听器探究水环境下激光脉冲与组织相互作用的过程,得出损伤范围与水层厚度以及激光脉冲等参数之间的关系；最后,利用ICR小鼠胚胎模拟临床手术,验证激光减胎的实用性和可行性。
[Abstract]:In recent years, with the development of assisted reproductive technology, reproductive science has achieved a great success in clinical practice. However, due to the widespread use of ovulation induction drugs and assisted reproductive technology, at the same time bring hope to many infertile couples also lead to increased incidence of multiple pregnancy. Multiple pregnancy may increase the risk of maternal and fetal in order to improve the multiple pregnancy pregnancy success rate, so for more than three fetal multifetal pregnancy, timely fetal reduction, 1-2 healthy living embryos retained after the operation, can achieve the purpose of fertility adverse consequences and can eliminate multiple pregnancy caused. The commonly used methods of fetal reduction should be adopted the needle machine piercing the gestational sac and fetal heart, can cause fetal movement, the influence of mechanical puncture accuracy, and these methods are susceptible to infection, time-consuming operation, operation difficulty is high.
With the development of laser technology and the increasingly mature, the use of laser on embryo reduction becomes a promising method for fetal reduction pulsed high energy. Therefore, we propose a new method of reducing fetal surgery, which uses 1064nm pulse laser focus directly on the gestational sac in embryos, optical breakdown through the effect of laser in the embryonic heart parts, causing damage to the embryonic heart, make rapid embryonic death, to fetal reduction purposes. This method avoids the mechanical needle puncture, and the laser pulse time is very short, as nanoseconds, avoid violent movement when the embryo is effect and thermal effect, greatly reduce the fetal reduction operation, improve the operation accuracy and has good application prospect in the field of assisted reproduction.
Based on the optical properties and mechanism of laser tissue interactions in water and biological tissues, to analyze the theory of laser fetal reduction, describes the basic principle of the laser optical breakdown effect occurred in the process of the tire; secondly, a theoretical model of laser shock wave from fetal reduction, safety, cavitation verify laser and thermal effects of the methods of fetal reduction; thirdly, the use of bovine muscle and pig fat tissue in biological experiments, relationship between laser parameters and damage size, optimizing the laser parameters used in the experiments; using high speed camera and the inquiry process and hydrophone tissue interaction of laser pulse water environment, the the relationship between the damage range and layer thickness and the laser pulse parameters; finally, simulation of clinical surgery by using ICR laser mouse embryos, verify the practicality and fetal reduction Sex.

【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R714.8

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