Cardiovascular effects of a sustained -Gz force in the horizontal position.

Introduction: The purpose of this investigation was to study the effect of a sustained -Gz force applied in the horizontal position on the cardiovascular system and the distribution of body fluids.

Methods: The study was conducted on four men who were submitted to two protocols. The principal difference between the two protocols was that in Protocol A the subjects remained supine, whereas in protocol B the subjects were submitted to a small -Gz force (0.

Electrical impedance measurements in the arm and the leg during a thirty day bed rest study.

The need to detect, follow and understand the effects of gravity on body fluid distribution is a constant stimulus to the quest for new techniques in this area of research. One of these techniques is electrical bioimpedance spectroscopy (BIS). Although not new, this is a technique whose applications to biomedical research are fairly recent.

Artificial gravity as a countermeasure of physiological deconditioning in space.

The displacement of humans from our planet to space and back to our planet or to another planet necessarily causes the exposure to transitional gravitational forces which create a need for countermeasures of physiological deconditioning. One of the alternative approaches to counteracting physiological deconditioning is the simulation of a gravitational field. An apparatus named the artificial gravity simulator (AGS) has been designed and constructed.

The cardiovascular response to the AGS.

An instrument, the AGS (artificial gravity simulator), has been built to produce artificial gravity. This paper reports preliminary results of experiments on human subjects conducted to study the cardiovascular response to various g-levels and exposure times.