摘要
本文利用单自由度非线性单腔模型描述激波作用下机体胸部动力学响应,并建立其数学模型,通过测定激波作用下的绵羊胸壁内向运动的位移、速度和加速度,检验这一模型的预测效果。实验结果表明,该模型基本上反映了激波作用下绵羊胸壁运动过程,但有待于发展和完善。
It has een shown that the lung blast injury occurs when blast waves act by way of the chest wall of human body. The inward impact of the chest wall upon the lungs with 20 m/s velocity in rabbits may cause. severe damage to the lungs. However, the sheep chest is anatomically similar to that of the human body and is more valuable in studying the mechanisms of blast injury of the lungs. In addition, it is necessary and possible to establish a mathematical model predicting the dynamic responses of the chest wall to blast waves. Based on the mathematical model, the parameters, including inward displacement, velocity and acceleration of the chest wall and the intra-thoracic pressure under the pressure of blasts can theoretically be calculated, and the physical parameters correlated with the severity of the lung injury.One chamber spring-mass model was used to stimulate the responses of the thorax to the blast waves. The chamber (with a piston and a volume of air) stood for the lungs. The chest wall moved with spring and damping. When the blast waves were loaded on the piston it moved inward and the pressure inside the chamber increased. The mathematical formula for the model was expressed as The model parameters were calculated according to body mass scaling, procedures. The mathematical equation for the model was solved with a digital computer using the Runga-Kutta method.Twenty-four adult sheep averaging 16.7+2.3kg of body weight were used for study.The results showed that the mean maximal values of the displacement could reach at 5.4 cm, 5.8cm when the sheep was exposed to blast waves with mean peak overpressures of 44.1 kPa and 70.1 kPa, respectively, and the mean maximal values of the velocity were 4.23 m/s and 5.43 m/s, respectively. The maximal value of acceleraton of chest wall exposed to peak overpressure of 44.1 kPa was 3400 m/s^2.The mathematical model proposed can be used to calculate the displacement, velocity and acceleration of the chest wall and the intra-thoracic pressures during the exposure to the blast waves with different overpressures and durations. The results of calculated Vmax, Amax and Smax values were identical with the measured ones.The one chamber spring-mass model can be used to calculate the displacement, velocity and acceleration of the chest Wall and the intrathoracic pressure when the human body is exposed to blast waves. The calculated physical parameters were coincided with the measured values in the sheep. This model is effective in predicting the dynamic responses of the chest wall to the blast waves.
出处
《生物医学工程学杂志》
EI
CAS
CSCD
北大核心
1990年第1期13-17,共5页
Journal of Biomedical Engineering
关键词
激波
胸部
动力学
数学模型
Blast wave
Blast injury
Mathematical model
Displacement
Velocity
Acceleration.
