体内氮气脱饱和与再饱和过程的数学模型  

A Mathematical Model for the Process of Desaturation and Resaturation of N 2 in Human Body

作　　者：杨天德[1] 张汝果[1] 张宝兰[1] 祁章年[1] 

机构地区：[1]航天医学工程研究所

出　　处：《航天医学与医学工程》1996年第3期179-183,共5页Space Medicine & Medical Engineering

摘　　要：研究了吸纯Ｏ２排Ｎ２和环境压力降低排Ｎ２的脱饱和过程以及环境压力升高溶解Ｎ２的再饱和过程，发现三个过程共同遵循着指数规律变化并建立了相应的数学模型，对减压病的预测和防护进行了理论探讨。其数学表达式为：ｖ＝ｖ＋（ｖ。－ｖ）ｅ－ｂｔ，ｖ表示ｔ时刻体内Ｎ２含量，ｖ。为初始稳定状态Ｎ２含量饱和值，ｖ为到达的终止稳定状态Ｎ２含量饱和值，ｂ为常数。其微分方程式为ｄｖ／ｄｔ＝－ｂ（ｖ－ｖ），表示某时刻体内Ｎ２的变化速率同Ｎ２含量瞬时值与到达终止状态的饱和值之差成正比。在利用文献中的实测结果确定出常数值以后，利用数学表达式计算出某时刻体内的Ｎ２含量和达到某Ｎ２含量所需时间。这一模型对航空、航天和航海中减压病的防护均有实际意义。N 2 content changes in human body were studied in the process of N 2 desaturation during preoxygenation or decompression and of N 2 resaturation during compression .It was found that the N 2 content change observed the exponential law with time and the corresponding mathematical model was established as follows: v=v+(v 0-v)e -bt . v─instantaneous value of N 2 content; v 0─ N 2 saturation value in initial and steady state; v─ N 2 saturation value in final and steady state; b─constant; A differential equation is written as :dv/dt=-b(v-v), which indicates that the change rate of N 2 content at a certain moment is proportional to the difference between instantaneous value and final-steady value of N 2 content in human body. The mathematical model may be applied to prevent against decompression sickness in aviation,navigation and space flight.

关 键 词：减压病 吸氧排氮 数学模型 氮 饱和 脱饱和 

分 类 号：R852.16[医药卫生—航空、航天与航海医学]