摘要目的 通过观察和比较不同体位下短臂离心机暴露所引起的心血管及前庭功能反应,进一步明确短臂离心机暴露下体位因素对心血管和前庭功能的影响. 方法 10名健康男性,依次进行75°、45°、15°后倾体位的短臂离心机暴露,且每体位先后进行2 G、3 G(足水平)人工重力暴露;采用便携式无创逐跳血压监测仪(Portapres)全程监测,并记录受试者血压、心率,通过Beatscope分析软件计算心脏泵血功能和总外周阻力;同时进行前庭功能评价,比较不同体位短臂离心机暴露对心血管、前庭系统的影响. 结果 2 G、3 G短臂离心机分别暴露时,15°体位下6名受试者出现严重运动病症状被迫终止试验;75°和45°两种体位下受试者血压、心率较基础值增高(F=2.79～16.44,P<0.05);心输出量则无显著变化.3 G暴露75°和45°两种体位时,每搏量显著降低(F=2.25、8.35,P<0.05).3 G暴露45°体位时总外周阻力较基础值增高(F=2.61,P<0.05);相同G值短臂离心机暴露时,75°体位下心血管功能变化较45°体位差异无统计学意义,而前庭功能评分则随着体位角度的减小而逐渐增高,15°体位下评分较45°和75°体位增高,差异有统计学意义(P<0.05). 结论 短臂离心机暴露时,45°和75°两种体位对心血管功能的影响无统计学意义,但不同体位对前庭功能的影响却差异较大.暴露体位越趋近于坐位,引起的运动病程度越重.

abstractsObjective To investigate the changes of human cardiovascular and vestibular functions when exposed to the artificiaI gravity generated by short-arm centrifuge with different body positions.Methods Ten healthy male volunteers were exposed to the artificial gravity at three different body positions:foot towards to the radial direction off the rotation center respectively with 75°,45°and 15°back tilting.Each position underwent on short-arm centrifuge with two sessions that were at 2 G and 3 G (at foot level) respectively.Beat-by-beat arterial blood pressure (BP) and heart rate (HR) were measured before and during the experiment by means of Portapres and calculated parameters,such as stroke volume (SV),cardiac output (CO) and total peripheral resistance (TPR),were obtained by Beatscope software.A subjective scoring was taken for assessing vestibular sensations. Results Six of 10 subjects with 15°posture were terminated both in 2 G and 3 G exposure due to their serious motion sickness symptoms.Comparing to the measurements before exposure,subjects with 45°and 75°posture showed significant increased BP and HR (F=2.79 to 16.44,P<0.05) but SV (F=2.25 or 8.35,P<0.05) while CO had no obvious change.Comparing to the measurements before exposure,subjects with 3 G (45°posture) showed significant incleased TPR (F=2.61,P<0.05).3 G exposure resulted in higher HR than that in 2 G.No significant changes of BP,HR,CO,SV and TPR were found between 45°and 75°postures under same exposure.The scores of vestibular assessment showed increased tendency with the decreased tilt angle.Significantly higher scores were got for 15°posture exposures comparing to others and indicated stronger vestibular stimuli.Conclusions The results suggested that the smaller tilted angle posture would result in mole serious vestibular symptoms.