High sustained +Gz and the diastolic heart: A finite element analysis.

摘要

Current and future fighter aircraft are capable of high sustained gravitational accelerations (HSG) upwards of nine times the force of gravity. This increase in acceleration magnitude greatly exceeds the natural adaption capabilities of the human body. Thus pilots who fly these aircraft require additional tools in order to operate effectively in this environment.; The present study is concerned with the displacement and stress generated on the diastolic human heart under HSG like those produced in fighter aircraft.; FEA was conducted at 4, 7 and 9 +Gz with and without the presence of an anti-G suit (AGS) and anti-G straining manoeuver (AGSM). The results show conclusively that without the use of AGS/AGSM, the heart undergoes significant displacement in the thorax, which results in a larger heart to head distance. This however is alleviated with an AGS/AGSM. Heart stresses during diastole were found to be within physiological norms both with and without the presence of an AGS/AGSM.