Analysis of intracranial pressure (ICP) through non-invasive method for Aviators Brazilian Air Force submitted to increased Gz load and strength in flight simulator test

• Grant number: 14/21803-7
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): August 01, 2015
• Effective date (End): July 31, 2017
• Field of knowledge: Biological Sciences - Physiology
• Principal Investigator: Sergio Mascarenhas Oliveira
• Grantee: Thiago Augusto Rochetti Bezerra
• Home Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

Factors related to human failures result in aviation incidents and accidents. According to statistics from the Accident Prevention and Investigation Center of the Brazilian Air Force (CENIPA), the pilots' physiological aspects were the cause of approximately 14% of the aviation accidents in Brazil, between the years of 2010 and 2012. Changes in intracranial pressure (ICP) during flight may negatively help increasing this statistics. Changes in blood pressure and in blood volume redistribution are caused by the exposure to high gravity acceleration (Gz). The cardiovascular changes caused by Gz acceleration result on increased hydrostatic gradient which is found in the venous and arterial systems. It happens mainly during acrobatic flights. The current project aims at monitoring intracranial pressure, according to a non-invasive procedure performed on Brazilian Air Force's pilots and cadets who are subjected to effort test in a force simulator (FAPESP 2005/5159) and during their acrobatic flights in the aircraft model EMB 312 T-27. A non-invasive sensor will be adapted on the pilot. It is a hardware linked to software that monitors intracranial pressure (FAPESP/ n. 12/ 50129-7). The non-invasive sensor detects micrometric cranial volume changes caused by pathophysiological variations in the respiratory and circulatory systems, the increase in cerebral tissue, or problems in the cerebrospinal fluid production/reabsorption ratio. Information gotten from this sensor are broadcasted, filtered and analyzed by appropriate software. This equipment is sensitive enough to record cranial variations stemming from heart beating and respiratory movements. The intracranial pressure variation will be analyzed during the experiment as well as the ICP frequency spectrum analysis, the morphology analysis of intra-cranial pressure pulse and the monitoring of the Pressure Reactivity Index (PRx) and of the Pressure Compensatory Reserve (RAP). The hypothesis advocated by the current project is that ICP related changes will happen during simulation and flight. Thus, the proposition of identifying and quantifying the non-invasive intracranial pressure in healthy individuals subjected to extreme conditions is of interest and completely justifiable. It opens many research fields on pharmacology, endocrinology, neurology and others. The present study aims at upgrading the knowledge on non-invasive ICP monitoring. Besides such parameter, the ICP analysis within the force simulator and that done during flight, with Gz load changes, presents unprecedented features. The benefits about to be found by the current research are not limited to aviation. Innumerable medical benefits can also be found by this research. The collected data might increase central nervous system tolerance to ischemic hypoxia as well as present results directly linked to neurologic (stroke) and cardiovascular diseases (heart attacks and sudden cardiac death).