[Method for predicting danger induced by longitudinal accelerations in the 'head-pelvis' direction]

The paper deals with the results of the studies aimed to validate the criterion of prediction of human tolerance to longitudinal tailward accelerations on the basis of structural changes in cardiac rhythm recorded directly during exposure. The experiments have been done on centrifuge with recording the sequences of cardiac intervals at rest and each stage of exposure with successively increasing intensity. Representation of basic information as two-dimensional distributions of cardiointerval durations based on the autocorrelation rhythmography method has been used. In order to develop a criterion together with the traditional statistical parameters the factors of instability of the internal structure of cardiac rhythm have been considered. All parameters then have been intercompared in terms of a simple function permitting optimization even with small volume of experimental material. The proposed criterion made it possible to predict with high significance tolerance to exposure with minimal intensity while the clinico-physiologic and traditional statistical indices enable one to assess it under significantly greater loads.