Studying the heart in a microgravity environment

Here on Earth, under the influence of gravity, a human heart has to make a considerable effort to pump blood to the upper organs. In weightless conditions this remains true, but the bodily fluids do not flow downwards as easily and thus tend to accumulate in the brain, causing what is known as the puffy-head syndrome, the consequence of a sudden change in the pull of gravity. Astronauts find that these disagreeable effects usually wear off after 2 or 3 days in orbit, once the organism has acclimatised to the conditions.

How does the cardio-vascular system adapt to this change in gravity?

This is the question being investigated by the Cardiolab project, a science module for studying the cardio-vascular system in a microgravity environment, which features as a part of the European Physiology Modules facility (EPM¹), one of the four laboratories on the Columbus module, attached to the ISS.

The Cardiolab system needs to satisfy the protocols drawn up by researchers into human physiology or operational medicine. Both flexible and adaptable, it may be used for observations in either stationary or ambulatory mode. The first type of experiment implies that when measuring, for example, variations in the volume of limbs during tests of venous occlusion, devices remain connected to the module. In ambulatory mode, devices are disconnected from Cardiolab.

The module consists of sensors (for measuring physiological parameters) and stressor devices (for applying stimuli to the subject). A data-management system coordinates the module, while storing the results of experiments and redirecting them to Cadmos, the centre responsible for operating the European equipment on the ISS.

The data collected are used in Space medicine for developing solutions to minimise the effects of variations in gravity and ensuring the well-being of flight crews. They are also likely to produce spin-offs that will be useful in human physiology, particularly concerning our understanding of cardio-vascular problems.

Cardiolab was set up in 1997 by CNES and the German Space Agency, DLR, which is also coordinating the development of the 10 sensors and stressors. CNES has developed the principal computer to which the instruments are connected and which is incorporated into the EPM rack, as well as two sensors; CNES is also responsible for operating the science module through Cadmos.

_{EPM: the European Physiology Modules facility is a laboratory developed as a part of the Microgravity facilities for Columbus (MFC) programme, a European contribution for microgravity investigations on the ISS.}

_{Last updated: August 2010}