短臂离心机锻炼对人体心血管功能的影响

发布时间：2018-05-10 04:57

本文选题：短臂离心机 + 人工重力　；参考：《第四军医大学》2008年硕士论文

【摘要】： 千百万年来,人类在长期的进化过程中,适应了地球表面的1G重力环境。在航天失重环境下,流体静压消失,体液头向分布,引发机体各生理系统出现一系列的适应性变化,对心血管系统、肌肉骨骼系统、前庭神经系统、血液系统、免疫系统等产生不良影响,严重影响航天员空间工作能力和飞行任务的完成,表现为返回地面后的立位耐力下降、运动能力下降等再适应不良的症状。为了保证航天员的身体健康、安全及工作效率,开展中长期失重对抗措施的研究是非常必要的。微重力暴露后的心血管功能失调与以下因素有关:①体液头向转移以及多尿引起血容量相对不足;②心脏功能减退;③阻力血管对交感刺激的反应性下降;④压力反射功能发生改变。目前的对抗措施主要包括运动、企鹅服、下体负压、水盐补充、抗荷服、营养、药物、肌肉电刺激以及飞行前适应性训练等。但这些措施不足以对抗航天环境给人体带来的不良影响,航天员仍然表现出立位耐力下降和进行性的骨质丢失。采用短臂离心机,可以在空间实现人工重力环境,是一种针对多个生理系统的综合对抗措施,有可能从根本上解决问题,具有较好的应用前景。既往研究表明,有氧运动有助于维持地面模拟失重被试者的血浆容量和运动能力,人工重力锻炼则有利于提高被试者的立位耐力。短臂离心机锻炼可将有氧运动锻炼和人工重力锻炼结合在一起,但是各因素在维持立位耐力中的作用以及以何种方式结合能更好地发挥对抗作用,至今尚无定论。我们改进设计的SAC-Ⅱ型短臂离心机,采用电力驱动方式,并可通过调节阻力矩定量人体运动负荷,有助于分别研究人工重力与运动负荷两种因素的对抗作用。本研究利用SAC-Ⅱ型短臂离心机,观察了短臂离心机不同水平+Gz暴露联合运动负荷时人体的心率和呼吸反应,同时选择一定的方案,观察了间断性人工重力联合运动锻炼对人体心脏功能、自主神经调节功能的影响,旨在为下一步地面模拟失重乃至载人航天飞行选择合适的人工重力对抗方案提供基础。本研究的实验结果及发现如下: 1.短臂离心机+Gz暴露联合运动负荷时心率和呼吸的变化本实验应用SAC-Ⅱ型短臂离心机,观察了不同方案离心机+Gz暴露联合运动负荷时人体心率、呼吸的变化。10名健康青年男性间断进行不同G值(1G,2G,3G)+Gz暴露,暴露的同时进行不同负荷(0W,30W,60W)运动锻炼。暴露过程中持续监测心率、呼吸的变化。结果发现:单纯+Gz暴露时心率较基础值显著增加(P0.05);+2Gz和+3Gz暴露联合30W、60W负荷运动时心率较相同负荷单纯运动时基础值均显著增加(P0.05);与单纯+Gz暴露相比较,+Gz暴露联合30W运动负荷时心率、呼吸显著增加(P0.01),联合60W运动负荷时进一步增加(P0.01),并随着G值的增大而增加。结果提示,+Gz暴露联合运动负荷时心率、呼吸的变化较单纯+Gz暴露更大。 2.三周间断性短臂离心机联合运动锻炼对人体心功能的影响本实验利用短臂离心机进行梯度G值联合运动负荷锻炼,观察了间断性人工重力锻炼3周后人体心脏收缩、泵血功能的变化。8名健康青年男性间断进行梯度G值(1G-2G)离心机联合30W运动负荷锻炼,每天30min,持续3周。采用心电机械图法和阻抗法测量锻炼前后心脏的收缩功能与泵血功能。结果发现:锻炼2周后被试者左室射血时间(LVET)及射血分数(EF)较锻炼前显著增加(P0.05),心率(HR)、射血前期(PEP)与LVET比值(PEP/LVET)显著下降(P0.05);锻炼3周后,LVET及EF进一步增加(P0.01),HR及PEP/LVET进一步下降(P0.05),同时PEP下降达到显著性,每搏量和总外周阻力显著增加(P0.05)。结果提示3周离心机联合运动负荷锻炼可显著增强心脏收缩与泵血功能。 3.间断性短臂离心机联合运动锻炼对心血管自主神经调节功能的影响本实验利用短臂离心机进行梯度G值联合运动负荷锻炼,观察间断性人工重力锻炼3周后人体心血管自主神经调节功能的变化。8名健康青年男性间断进行梯度G值(1G-2G)离心机联合30W运动负荷锻炼,每天30min,持续3周。记录心电图和逐跳连续血压,运用自回归谱分析法得到心率变异性(HRV)与收缩压变异性(SBPV)功率谱。锻炼前后进行头高位倾斜联合下体负压测试,观察立位应激时心血管功能变化。结果发现:在卧位休息时,锻炼3周后被试者HRV的低频与高频比值较锻炼前显著下降(P0.05),SBPV的低频功率较锻炼前显著增加(P0.05)。在头高位倾斜联合下体负压试验时,锻炼后被试者心率较锻炼前显著下降(P0.05),总外周阻力显著增加(P0.05),每搏量呈增加的趋势。结果提示,离心机联合30W运动锻炼3周可以增加平卧位心脏迷走神经与外周血管交感神经活动水平,增强立位应激时血压调节能力,提高了心血管功能储备。总之,本研究观察了短臂离心机锻炼对人体心血管功能的影响,发现+Gz暴露联合运动负荷时心率、呼吸的变化较单纯+Gz暴露更大,并发现间断性梯度G值(1G-2G)联合30W运动负荷锻炼3周可增强人体心脏收缩与泵血功能,增加平卧位心脏迷走神经与外周血管交感神经活动水平,增强了立位应激时血压的调节能力,提高了心血管功能储备。本工作对下一步地面模拟失重乃至载人航天飞行选择合适的人工重力对抗方案具有一定意义。
[Abstract]:For millions of years, human beings have adapted to the 1G gravity environment on the surface of the earth for a long period of time. In the environment of weightlessness, the hydrostatic pressure disappears and the body fluid head distributes, causing a series of adaptable changes in the body's physiological systems, for the cardiovascular system, the skeletal system of the muscle, the vestibule nervous system, the blood system, the immune system and so on. There is a bad effect, which seriously affects the astronaut's ability to work in space and the completion of the flight task. It is manifested in the decline of the standing position after returning to the ground, the decline of the movement ability and so on. It is necessary to carry out the study of the medium and long term weightlessness Countermeasures in order to ensure the health, safety and efficiency of the astronauts.
The cardiovascular dysfunction after microgravity exposure is related to the following factors: (1) the head fluid head transfer and the relative insufficiency of the blood volume caused by polyuria; (2) the impairment of the heart function; (3) the reactivity of the resistance vessels to sympathetic stimulation; (4) the change of the pressure reflex function. The current countermeasures mainly include exercise, Penguin clothes, lower body negative pressure, water salt. Supplementation, anti load clothing, nutrition, drugs, muscle electrical stimulation, and pre flight adaptive training, but these measures are not enough to counter the adverse effects of the space environment on the human body. The astronauts still show a decline in standing tolerance and progressive bone loss. The comprehensive countermeasures against multiple physiological systems may solve the problem fundamentally and have a good application prospect.
Previous studies have shown that aerobic exercise helps to maintain the plasma volume and exercise capacity of ground simulated weightless subjects. Artificial gravity exercise helps to improve the standing endurance of the subjects. The short arm centrifuge exercises can combine aerobic exercise with artificial gravity exercise, but the effects of various factors on the maintenance of orthostatic endurance are We have improved the design of the SAC- type II short arm centrifuge, using the electric drive mode, and by adjusting the resistance moment to quantify the human motion load, it is helpful to study the antagonism of two factors, the artificial gravity and the motion load, respectively.
In this study, SAC- II short arm centrifuge was used to observe the heart rate and respiratory response of the human body at different levels of +Gz exposure and exercise load at different levels of the short arm centrifuge. At the same time, a certain scheme was chosen to observe the effects of intermittent artificial gravity combined exercise on the function of the human heart and the function of the autonomic divine regulation, aiming at the next step of the ground model. Weightlessness and even manned spaceflight provide the basis for selecting the appropriate artificial gravity countermeasures.
The results of this study are as follows:
1. the change of heart rate and respiration during +Gz exposure combined with exercise load in short arm centrifuge, SAC- II short arm centrifuge was used to observe the human heart rate of different program centrifuges with +Gz exposure combined with exercise load, and the changes of respiration in.10 healthy young men were interrupted by different G values (1G, 2G, 3G) and exposed to different loads at the same time. (0W, 30W, 60W) exercise. Continuous monitoring of heart rate and respiration during exposure. Results showed that heart rate of pure +Gz was significantly increased (P0.05); +2Gz and +3Gz exposure combined 30W, 60W load exercise was significantly increased (P0.05) compared with simple +Gz exposure (P0.05); +Gz exposure was compared with simple +Gz exposure The heart rate and respiration increased significantly (P0.01) during the exercise load (30W), and increased with the combined 60W exercise (P0.01), and increased with the increase of G value. The results suggested that the heart rate and respiration of +Gz exposure combined with exercise load were more than those of pure +Gz exposure.
2. three weeks of intermittent short arm centrifuge combined exercise exercise on human heart function in this experiment, the experiment used the short arm centrifuge to carry out the gradient G value combined exercise load exercise, and observed the heart contraction of the human body after 3 weeks of intermittent artificial gravity exercise and the change of pump blood function,.8 healthy young male sex discontinuous performed gradient G value (1G-2G) centrifuge combined with 3 0W exercise load exercise was 30min daily for 3 weeks. The systolic function and blood pump function of the heart before and after exercise were measured by electrocardiography and impedance method. The results showed that the left ventricular ejection time (LVET) and ejection fraction (EF) were significantly increased (P0.05), heart rate (HR), and the ratio of PEP to LVET (PEP/LVET) after 2 weeks of exercise (PEP). After 3 weeks of exercise (P0.05), LVET and EF were further increased (P0.01), HR and PEP/LVET were further decreased (P0.05), while PEP decreased significantly, and the stroke volume and total peripheral resistance increased significantly (P0.05). The results suggested that the cardiac contractility and pump function could be significantly enhanced by the combined exercise load exercise of the centrifuge at 3 weeks.
The effect of 3. intermittent short arm centrifuges combined exercise exercise on cardiovascular autonomic nervous regulation in this experiment, a gradient G value combined exercise load exercise was performed with a short arm centrifuge, and the changes of autonomic nervous regulation in the human body were observed after 3 weeks of intermittent artificial gravity exercise, and the gradient G value of.8 healthy young men was interrupted intermittently (1G-2G ) the centrifuge combined with 30W exercise, 30min per day for 3 weeks. Recording electrocardiogram and continuous blood pressure by hop by hop, using autoregressive spectral analysis to get the heart rate variability (HRV) and systolic pressure variability (SBPV) power spectrum. The head position tilt combined with lower body negative pressure test before and after exercise, and observe the changes of cardiovascular function during the position stress. The ratio of low frequency to high frequency of HRV was significantly lower than that before exercise (P0.05), and the low frequency power of SBPV was significantly increased (P0.05). The heart rate of the subjects after exercise was significantly lower than that before exercise (P0.05), and the total peripheral resistance increased significantly (P0.05), and the total peripheral resistance increased significantly (P0.05), and the total peripheral resistance increased significantly (P0.05). The results suggest that the 3 weeks of 30W exercise combined with centrifuge can increase the level of sympathetic activity of the vagus nerve and peripheral vessels in the supine position, enhance the ability to regulate blood pressure and improve the reserve of cardiovascular function.
In conclusion, this study observed the effect of the short arm centrifuge exercise on the cardiovascular function of the human body. It was found that the changes of heart rate and respiration in +Gz exposure combined with exercise load were greater than that of simple +Gz exposure, and the intermittent gradient G value (1G-2G) combined with 30W exercise exercise could increase the cardiac contractile and pump function of the strong human body for 3 weeks, and increase the cardiac vagus in the supine position. The level of the sympathetic activity of the nerve and peripheral vessels enhances the regulating ability of the blood pressure and the reserve of cardiovascular function. This work is of certain significance to the choice of the appropriate artificial gravity countermeasures for the next ground simulated weightlessness and even the manned space flight.

【学位授予单位】：第四军医大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R85

【参考文献】