Desenvolvimento de uma câmara de pressão positiva para estudos em fisiologia espacial

Abstract

Missions to Mars and return astronauts to the Moon may be true in the near future, which will expose them upon hypogravity environments. Some techniques are applied to simulate gravitational force reduced to prepare the crew to better adapt to those environments. This study aimed to develop a prototype of a lower body positive pressure (LBPP), as an alternative to the simulations currently used. This device is able to unload a volunteer on a physical exercise device, creating a hypogravity environment, simulating the human gait, for studies in space physiology. For development of the LBPP was necessary planning since its conception until the final prototype with functionality testing. A control system has been implemented for closed-loop pressure control. Equipment were identified and adapted such as blower, frequency inverter to control the blower, sensors (pressure, temperature and humidity), load cells to measure apparent weight of volunteer, microcontroller, treadmill for gait simulation and Neoprene short for connection of volunteer to a Neoprene membrane. Equipment and instrumentation were also developed to integrate and facilitate the system. Was developed the main chamber of a flexible PVC material, a metallic structure for height adjustment. Also was developed the instrumentation of load cells, as well as instrumentations of the sensors to adapt and read by the microcontroller. Furthermore it was necessary to develop software for data acquisition, the instrumentation of the blower and the frequency inverter to digital control by the microcontroller and an emergency circuit to ensure safety operation of the equipment. Experimental results shown that the LBPP is able to reduce the apparent weight of a load with similar weight values on Mars and the Moon, reaching the goal, where it was possible to verify that the pressure ratio and apparent weight is inversely proportional, which confirmed the theory.