推拉效应模拟方法及防护训练方案的研究

发布时间：2018-01-11 11:01

本文关键词：推拉效应模拟方法及防护训练方案的研究　出处：《第四军医大学》2007年博士论文　论文类型：学位论文

【摘要】： 持续性正加速度(+Gz)致意识丧失(G-LOC)的机理及其预警和防护是航空医学的重要问题。高性能战斗机在作战或训练飞行时,从0G或-Gz的飞行状态突然转为持续性正加速度作用时,致使飞行员+Gz耐力下降,比单纯+Gz作用更易发生意识丧失的现象称为推拉效应(push-pull effect,PPE)。考虑到空战中攻击性动作的需要及飞机机动性能的不断提高,飞行时±Gz交替出现的机率更高,PPE有增加的趋势,其对飞行安全构成了严峻的挑战。因此,推拉效应近年来迅速成为航空医学加速度生理领域新的研究热点。现代高性能战斗机在空战机动中虽然通常不做持续性高水平的-Gz动作,但在如俯冲攻击、散开、导弹规避、半滚倒转等机动飞行中仍存在推拉动作。虽然军事飞行中的-Gz比特技飞行中少、小、短,其对随后的+Gz耐力的影响仍不容忽视。对于推拉效应的发生机理,多数学者认为,在-Gz时,血液头向惯性移位,引起颈动脉窦、主动脉弓压力感受器强烈的神经反射,产生心动徐缓,心输出量大量减少,总外周阻力降低的效应,导致心水平血压降低。-Gz结束后,上述效应并不能立即消退,因此在随后+Gz作用时,头水平血压比没有预先-Gz作用时降低更严重。-Gz不但使随后+Gz时的头水平血压更加下降,而且损害了人体对+Gz的代偿反应,从而使+Gz耐力下降,下降程度随预先-Gz作用G值和时间增大而增大。近年来的研究进一步发现,外周血管本身存在的慢收缩、快舒张特点可能也是推拉效应发生的重要原因。目前通过模拟推拉动作对其效应进行研究的设备和方法已有多轴向载人离心机、科里奥利加速度平台、垂直旋转装置、垂直旋转床以及灌注回路等。但在部队实际应用中,除了对飞行员进行卫生宣教,尽力避免可能导致推拉效应的推拉动作,或提前做抗G收紧动作外,尚无专门的设备及针对性的防护训练方案对推拉效应进行对抗。本研究利用下体负压并联合旋转床建立了推拉动作的模拟方法,并观察下体负压联合旋转床、反复体位改变及自行下体负压训练器训练后心血管调节能力的改变及其在推拉效应中的作用,为建立推拉效应针对性的地面防护方案开辟新的途径。本研究的主要结果与发现如下: 1.下体负压联合旋转床模拟推拉动作的心血管反应本实验采用-70mmHg下体负压联合旋转床模拟推拉动作,观察预先不同角度头低位(HDT)后+90°头高位(HUT)与单纯+90°HUT对照时心率、血压及泵血功能的变化。结果表明,在旋转床模拟推拉动作时,不同角度HDT后的HUT时,收缩压(SBP)、舒张压(DBP)、平均动脉压(MAP)及总外周阻力(TPR)与对照相比均显著降低(P0.05),且随预先倾斜角度的增大降低越显著。不同角度HDT后的HUT时每搏量(SV)、心输出量(CO)较对照显著升高(P0.05),与预先倾斜角度无相关关系。在下体负压联合旋转床模拟推拉动作时,不同角度HDT后的HUT时SBP、DBP、MAP变化不明显,而SV、CO则较对照显著升高(P0.05),TPR显著降低(P0.05)。结果提示,下体负压联合旋转床模拟推拉动作时心脏泵血功能改变与旋转床模拟推拉动作相似,但是血压变化呈现一定的变异性。 2.反复体位改变训练后的心血管反应本实验观察了每天1次、连续6天反复体位改变训练后在平卧位、模拟推拉动作及HUT实验时心率、血压、心脏泵血功能及自主神经调节的改变。结果表明,训练6天后,平卧位血压、心脏泵血功能较训练前呈降低趋势,心率变异性(HRV)分析的高频功率谱(HFn)升高,而低频功率谱(LFn)降低,且压力反射敏感度(BRS)降低。训练6天后,模拟推拉动作测试的HUT阶段及HUT实验时,血压较训练前明显降低(P0.05),心脏泵血功能呈降低趋势。结果提示,本实验所采用的反复体位改变训练方案由于头低位较头高位所占比重大,可降低推拉动作时血压及对直立位应激的反应能力,因此不适宜应用于推拉效应的地面防护训练方案。但是这一降血压效应可能更加适宜于航天员训练来减轻在航天中出现的航天适应综合征。 3.下体负压联合旋转床模拟推拉动作训练后的心血管反应本实验观察了每天1次、连续6天的下体负压联合旋转床模拟推拉动作训练后在平卧位、模拟推拉动作及HUT实验时心率、血压、心脏泵血功能及自主神经调节的改变。结果表明,训练6天后,平卧位SBP较训练前无明显改变,DBP、MAP呈降低趋势。SV、CO较训练前呈升高趋势,TPR呈降低趋势。HRV分析的HFn降低,而LFn及LF/HF升高。收缩压变异性(SBPV)分析的LFn降低,压力反射敏感度(BRS)降低。模拟推拉动作测试的HUT阶段及HUT实验时,血压较训练前呈降低趋势,而心脏泵血功能则呈升高趋势。结果提示,训练6天后心脏泵血功能增强,心交感紧张度增加,但是训练后外周交感缩血管紧张度降低导致的低水平总外周阻力,影响了其对立位应激的血压维持。这种推拉动作的适应性训练方案还需要进一步改进与评价。 4.自行下体负压训练器训练后的心血管反应本实验观察了每天1次、连续10天的自行下体负压训练器训练后在平卧位、模拟推拉动作及HUT实验时心率、血压、心脏泵血功能及自主神经调节的改变。结果表明,训练10天后,平卧位血压及心脏泵血功能较训练前显著升高(P0.05)。HRV分析的HFn降低,而LFn升高,但未达到显著水平。SBPV分析及BRS在训练后无明显改变。训练后的模拟推拉动作HUT阶段及HUT实验中,SBP、DBP、SV及CO较训练前显著升高(P0.05)。结果提示,自行下体负压训练器训练可以提高受试者的基础心血管水平,增强其对立位应激的调节能力,可能对推拉效应的防护具有一定的作用,可用于战斗机飞行员进行地面抗荷生理训练。总之,本研究建立了下体负压联合旋转床模拟推拉动作的方法,探讨了反复头低位、下体负压联合旋转床及自行下体负压训练后人体的心血管反应,发现反复体位改变训练不适宜用于推拉效应的地面训练,可能更加适宜于航天员训练以减轻在航天飞行中出现的航天适应综合征;下体负压联合旋转床模拟推拉动作训练的效果需要进一步评价;自行下体负压训练器则可用于推拉效应的地面防护训练。本工作对进一步开展推拉效应的机制研究,制定针对推拉效应的防护训练方案具有重要价值。
[Abstract]:The mechanism and early - warning and protection of sustained positive acceleration ( + G - LOC ) induced loss of consciousness ( G - LOC ) is an important problem in aviation medicine . When high - performance fighter aircraft are in combat or training flight , the flight state from 0 G or - G is suddenly converted to continuous positive acceleration . The phenomenon of loss of consciousness is called push - pull effect ( PPE ) . Considering the need of aggressive action in air combat and the continuous improvement of aircraft maneuverability , there is a trend of higher probability of + and + / - G alternation in flight , which poses a serious challenge to flight safety . Therefore , the push - pull effect has become a new hot spot in the field of airborne medical acceleration in recent years . Although the high - performance fighter usually does not do a continuous high - level - G - G operation in air combat maneuver , there is still a push - pull maneuver in maneuvering flight such as dive attack , spread , missile avoidance , semi - roll inversion and so on . Although the military flight has fewer and less than the technical flight , its influence on the subsequent + G - G endurance is still not to be ignored . In recent years , it has been found that the slow contraction and rapid relaxation of the peripheral blood vessel itself may also be the important cause of the push - pull effect . At present , the equipment and the method for researching the effect of the push - pull action have many axial manned centrifuge , Coriolis acceleration platform , vertical rotating device , vertical rotating bed and perfusion circuit , etc . However , in the practical application of the force , besides the health education of the pilot , trying to avoid the push - pull action which can lead to the push - pull effect , or to make the anti - G tightening action in advance , there is no special equipment and the targeted protection training scheme to combat the push - pull effect . This study establishes a simulation method of push - pull action by using the lower body negative pressure and combined rotating bed , and observes the changes of the cardiovascular regulating ability after training of the lower body negative pressure combined rotating bed , the repeated posture change and the self - lower body negative pressure training device and the role in the push - pull effect , and opens up a new approach for the establishment of the ground protection scheme aiming at the push - pull effect . The main findings and findings of this study are as follows : The results showed that systolic blood pressure ( SBP ) , diastolic blood pressure ( DBP ) , mean arterial pressure ( MAP ) and total peripheral resistance ( TPR ) decreased significantly ( P0.05 ) . 2 . Cardiovascular response after repeated posture change training The changes of heart rate , blood pressure , heart pump blood function and autonomic nervous regulation were observed in the supine position , simulated push - pull action and HUT experiment after 6 days of training . The results showed that the repeated posture change training scheme adopted in this experiment was significantly lower than that before training ( P0.05 ) . 3 . Cardiovascular response after simulated push - pull action of lower body negative pressure combined rotating bed The changes of heart rate , blood pressure , cardiac pump blood function and autonomic nervous regulation were observed in the supine position , simulated push - pull operation and HUT experiment . The results showed that after 6 days of training , the SBP of the supine position decreased significantly , while LFn and LF / HF were decreased . 4 . Cardiovascular response after self - made negative pressure trainer The results showed that SBP , DBP , SV and CO increased significantly ( P0.05 ) after training for 10 days . SBP , DBP , SV and CO increased significantly after training for 10 days ( P0.05 ) . In conclusion , this study establishes a method for simulating push - pull action of the lower body negative pressure combined rotating bed , and discusses the cardiovascular response of the human body after repeated head and low pressure combined rotating bed and self - body negative pressure training . It is found that the repeated posture change training is not suitable for the ground training of push - pull effect , and it may be more suitable for astronaut training to reduce the space adaptation syndrome in space flight ; the self - lower negative pressure training device can be used for ground protection training of push - pull effect .

【学位授予单位】：第四军医大学
【学位级别】：博士
【学位授予年份】：2007
【分类号】：R85

【引证文献】