脊髓冲击伤模拟装置的研制与应用

Development and application of the simulated system for spinal blast injury

目的 研制一种小型冲击波发生装置,模拟爆炸冲击波的致伤作用.方法 根据气体动力学原理,采用破膜技术及传感器检测技术,设计出一种由储气设备、发射系统、冲击波测试分析系统、动物固定装置4部分组成的小型冲击波发生装置.设定气源压力分别为400、500、600、700、800 kPa,记录管口处冲击波超压峰值、峰值持续时间及冲击波传播速度.不同的气源压力分别重复5次.将24只新西兰大白兔按数字表法随机分为4组,每组6只.A组：对照组;B组：气源压力400 kPa组;C组：气源压力600 kPa组;D组：气源压力800 kPa组.将兔T9和T10全椎板切除显露硬膜囊,应用该装置按预设气源压力实施单次冲击波致伤,对照组不给予冲击.48h后观察各组兔后肢运动、感觉功能变化以及脊髓病理学变化.结果 该装置所产生的波形类似典型空气冲击波波形.随着气源压力的增大,冲击波超压峰值及速度同时增大,峰值持续时间基本不变.B、C、D各组随着气源压力的增大,兔后肢运动、感觉功能损害明显加重,各组动物运动及感觉功能评分差异有统计学意义（P〈0.01）.结论 本装置能模拟产生冲击波,且性能稳定、安全,可重复性强.应用于致伤脊髓,能较好地模拟轻、中、重不同程度的脊髓冲击伤.

Objective To develop a small blast-wave-generating system for the simulation of the effect of blast waves on injuries.Methods The system consisting of the gas storage chamber, the launching device, the blast wave analysis system and the animal fixer was developed with the principles of air dynamics, the technique of membrane rupture and sensor detection technology. Pressures of the gas source were set at 400, 500, 600, 700 and 800 kPa. Ultra pressure peak values, peak sustaining time and transmitting velocity of blast waves were recorded at the opening. 24 New Zealand white rabbits were randomly divided into 4 groups： group A （the control group）, group B （with a gas pressure source of 400 kPa）, group C （with a gas pressure source of 600 kPa）, group D （with a gas pressure source of 800 kPa）, each consisting of 6 animals. Laminectomy was performed at T9 and T10 to expose dura mater bursa. All the animals in the experimental groups with the exception of those in the control group sustained injuries with a single blast wave of different gas pressures. After 48 hours of injury, changes in the hind limb movement, sensory function and spinal cord pathology were evaluated with histological analysis.Results The waveform of the system was similar to the Friedlander waveform, a typical air-blast waveform. Positive pressure peak and propagation velocity increased with the increase of gas pressures, while the duration of pressure peak remained basically unchanged. For the animals in the B, C, and D groups, sensory and motor functions deteriorated obviously with the increase of gas pressures. Statistical significance could be seen in the scores of sensory and motor functions（P〈0.01）.Conclusions The developed system was capable of simulating blast waves, with the features of stable performance, safety and good reproducibility. It could ideally be used to simulate light, moderate and severe spinal cord blast injuries.