The report of cosmonauts Mikhail Kornienko and Sergey Volkov on “Algometry” space experiment.
M. Kornienko: Dear visitors of the “Planeta Koroleva” portal!
Today we, the International Space Station cosmonauts, Sergey Volkov and Mikhail Kornienko, want to tell your about one more medical experiment, which is being conducted onboard the International Space Station, it is called “Algometry”.
This experiment relates to “Human in space” biomedical researches section. The experiment is produced by the Institute of Biomedical Problems. It is a new experiment, which started last year onboard the ISS.
The “algometry” experiment is an investigation of human’s pain sensitivity in the space flight conditions. The experiment is fulfilled in order to update methods of delivery of health care to cosmonauts during space flight. This method gets the greatest urgency in perspective long-duration interplanetary flights, when there is no possibility of the injured person’s evacuation from the flight vehicle board.
The essence of measuring threshold of pain sensitivity, which is the main characteristic in the experiment, is in the pain sense quantitative estimation in order to choose anaesthetic medications, diagnostic and treatment methods and manipulations and other techniques. The pain threshold is unique for each person, i.e. sensitivity to pain of different people differs. Besides, for each concrete person the pain threshold depends on his state of health, biological and social adaptation. It is also interesting to understand if the pain threshold changes in weightlessness or not?
Studying pain sensitivity threshold in “Algometry” experiment is conducted by two methods: method of mechanical irritation of skin surface’s certain point (tenzoalgometry) and thermal irritation method (thermal algometry). We apply both methods before and after the flight, and during the flight only tenzoalgometry method is yet applied.
The pain sensitivity threshold is being measured before space flight, during and after flight, these values are compared to understand space flight factors’ influence on cosmonaut’s status. The first survey during the flight should be carried out after two weeks of stay onboard the ISS, further with regularity once a month with permissible deviation for one-five days.
S. Volkov: Mikhail Kornienko has now prepared equipment for performing experiment “Algometry” by tenzoalgometry method. The scheme is connected up, grounding, power cable are attached.
|Рис.1. “Algometer”, front view||РРис.2. “Algometer”, back view|
Tenzoalgometry is carried out with the help of special equipment – “Algometer”. “Algometer” measures pressure force while pressing certain point on the body surface. Having achieved pain threshold, the testee releases a special button on the equipment, thus fixing digital value of the pressure force and finishing pain test.
In order to begin measurement of pain sensitivity’s threshold, it is necessary to take in hands “Algometer” and to put middle finger of the right hand in the hollow on the back panel, having pressed it with finger-cushion to the internal wall of the equipment. Then press “Start” button on the front plate of the equipment and hold the button till the occurrence of disagreeable sensations (pain threshold). Having achieved pain threshold, it is necessary to release button “Start” and finish measurements. There even can be seen the print of the rod, which was pushing the finger.
The mechanical irritation method is done by smooth increase of pressure on definite body area. Pain sense appears in the moment when pressure force reaches values, sufficient for receptors’ stimulations. The pain sensitivity threshold value during tenzoalgometry is expressed by units of pressure force relative to the area unit (kgf/sm2). Tenzoalgometry method allows for obtaining reliable information on the pain sensitivity status on different body areas.
After the measurement being carried out, the results are recorded on flash memory card, where they are kept and then returned to the Earth after completing the expedition.
The second means of pain sensitivity threshold measurement is fulfilled by the thermal algometry method. At the present time this method is only used before and after spaceflight, during the flight this method will be used in 2017th. In order to conduct thermal algometry in this experiment there is used methodology of gradual increase of heating copper contact plate with help of “Thermal probe” equipment. “Thermal probe” is used for warming up skin in the area of the forearm on purpose of creating controlled pain senses of the cosmonaut. Having achieved pain threshold, the testee releases the button and records the temperature value. Examinations’ results while conducting thermal algometry are registered in Celsius degrees.
Fig.3. “Thermal probe”
During the Space Experiment “Algometry” to achieve objective results both methods are used, because results of pain sensitivity studies by various methods can not coincide. For study results’ registration and for received data storage there is used a special software, installed onboard medical computer RSE-Med. By means of PMO these results are saved in data file, which after returning to the Earth is transferred to the experiment director – Institute of Biomedical Problems for further processing and analysis.
Preparing for the flight, we hoped, and it was confirmed by the flight itself, that we experienced the pain only in “Algometry” experiment, and as to the rest the space flight brings us only joy and satisfaction from well performed job.