高压氧舱治疗对眼眶损伤患者视神经影响的有限元模拟研究

发布时间：2018-07-23 13:26

【摘要】：高压氧(HBO)在医学上的应用历史虽短,但它对某些疾病的独特疗效已引起医学界的日益重视。积极预防高压氧治疗中副作用和并发症,对保证高压氧治疗的顺利进行和疗效有重要的意义。视神经(optic nerve)由特殊躯体感觉纤维组成,传导视觉冲动。视神经损伤,最终影响视功能并可导致失明。由于视神经损伤一旦发生则不可逆转,即使经过治疗,受损的视功能也无法恢复。眼眶受损患者在进行高压氧治疗时,视神经是否会受到压迫还未见文献报道。本文在合理简化和假设的前提下,通过建立带组织的受损眼眶三维有限元模型,模拟视神经在高压情况下的受力情况,对受损眼眶侧的视神经和完整眼眶侧的视神经应力进行对比并结合患者的实际情况进行了分析。这些研究成果可为眼眶受损患者可否做高压氧舱治疗提供力学依据,避免视神经在治疗过程中受到压迫,也为日后更加深入细致的研究视神经在体受力状况打下了良好的基础。本文的主要工作如下: 1.根据受损的人体头部CT扫描图像,利用逆向工程原理在MIMICS软件(试用版)中提取各组织的几何轮廓。 2.利用提取的各组织的几何轮廓,在ANSYS软件中建立带组织的受损眼眶三维有限元模型。为了能真实的反映视神经在人体中的情况,带组织的受损眼眶有限元模型中包括了视神经、受损眼眶、眼球、眶脂体和脑组织,共46189个节点,249115个单元。模型生物材料特性均采用弹性模型描述。 3.结合视神经在高压氧仓中的情况进行有限元模型模拟。在ANSYS软件中,利用带组织的受损眼眶模型模拟视神经在高压下的受力情况。由有限元模拟结果得到了以下几个结论: 1.受损眼眶侧和完整眼眶侧的视神经最大应力均发生在视神经和眼球的接触部位。这和眼内压升高压迫了视神经的结论是一致的。 2.颅骨可以有效地保护视神经不受外力伤害。外界压强保持不变,随着受损眼眶侧的颅骨弹性模量的降低,受损眼眶侧的视神经应力逐渐增大。 3.颅骨弹性模量保持不变,随着外界压强的增加,视神经的最大应力均迅速增加。说明在高压氧仓治疗中,视神经有可能受压迫。 4.受损眼眶侧视神经的应力远远大于完整眼眶侧的视神经。
[Abstract]:Although the application of hyperbaric oxygen (HBO) in medicine is short, its unique effect on some diseases has been paid more and more attention. Active prevention of side effects and complications in hyperbaric oxygen therapy is of great significance to ensure the smooth progress and curative effect of hyperbaric oxygen therapy. The optic nerve (optic nerve) is composed of special somatosensory fibers and transmits visual impulses. Optic nerve injury ultimately affects visual function and can lead to blindness. As the optic nerve injury is irreversible, even after treatment, damaged visual function can not be restored. Whether the optic nerve will be compressed during hyperbaric oxygen therapy in patients with orbital damage has not been reported. On the premise of reasonable simplification and hypothesis, this paper simulates the stress of optic nerve under high pressure by establishing a three-dimensional finite element model of injured orbit with tissue. The stress of the optic nerve in the injured orbital side and the intact orbital side was compared and analyzed in combination with the actual situation of the patients. These results can provide a mechanical basis for the treatment of hyperbaric oxygen chamber in patients with orbital injury, avoid the compression of optic nerve in the course of treatment, and lay a good foundation for a more thorough and detailed study of the stress status of optic nerve in vivo in the future. The main work of this paper is as follows: 1. According to the CT scan image of the damaged human head, the geometric contours of each tissue were extracted from the MIMICS software (trial version) using reverse engineering principle. 2. The 3D finite element model of injured orbit with tissue was established by using the geometric contour of each tissue extracted in ANSYS software. In order to truly reflect the optic nerve in human body, the finite element model of injured orbit with tissue includes optic nerve, injured orbit, eyeball, orbital fat body and brain tissue, with 46189 nodes and 249115 units. The properties of model biomaterials are described by elastic model. 3. The finite element model of optic nerve in hyperbaric oxygen chamber was simulated. In ANSYS software, the injured orbital model with tissue was used to simulate the stress of optic nerve under high pressure. The following conclusions are obtained from the finite element simulation results: 1. The maximum stress of the optic nerve in the injured orbital side and the intact orbital side occurred at the contact point between the optic nerve and the eyeball. This is consistent with the conclusion that increased intraocular pressure compresses the optic nerve. 2. 2. The skull can effectively protect the optic nerve from external force. The stress of optic nerve increased gradually with the decrease of elastic modulus of skull in the injured orbital side. The elastic modulus of skull remains unchanged, and the maximum stress of optic nerve increases rapidly with the increase of external pressure. It is suggested that the optic nerve may be compressed in hyperbaric oxygen chamber therapy. 4. 4. The stress of the injured orbital optic nerve is much greater than that of the intact orbital optic nerve.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：R779.1

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