The "Algometry" experiment, which studies the pain threshold of cosmonauts, continues on the ISS. During interplanetary flights, cosmonauts cannot be sent to a hospital on Earth; they will need space medical assistance. In order to provide it effectively, information about the pain threshold is very valuable: in space, it becomes higher.
Many factors influence this. In particular, in zero gravity, blood and other fluids are distributed differently throughout the body, and the central nervous system begins to change during prolonged stays in space. The level of hormones adrenaline and cortisol in the blood can also affect the pain threshold. Stress and adaptation to zero gravity "push" pain into the background, and a person simply does not feel or recognize it.
A special device called an algometer is used for the experiment. Inside the device is a small pin. It presses on the finger while the cosmonaut holds down a button on the device, and the button can only be released when the cosmonaut feels pain.
Another sensor of the device is a small plate that is applied to the forearm and gradually heated until it begins to cause pain. The device records the pain threshold indicators, and they are studied on Earth.
"Algometry" has been conducted since the spring of 2015, and all Russian cosmonauts arriving at the ISS participate in the experiment. According to RSC Energia, this will be one of the longest Russian space experiments.
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