The Physiological Effects of Acute and Ramp Simulated Altitude Exposure During Simulated Flight Tasks

Study Overview
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Brief Summary
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• The purpose of this study is to investigate which physiological process that controls normal human body homeostasis is affected by low levels of acute hypoxic exposure and whether there is a difference in those physiological processes and simulated flight performance between a rapid and ramp hypoxic exposure. To accomplish this, pilot analogs will be exposed to normoxic, simulated 8,000 ft (2438 m), simulated 12,000 ft (3658 m), and a ramp exposure breathing at simulated 8,000 ft for 5 minutes before ascending to simulated 12,000 ft while flying in a flight simulator. During the flight simulator, participants will need to accomplish three tasks: 1) Maintaining an altitude of 5,000 ft of elevation while performing a mental math test, 2) Flying the aircraft through the center of a series of 7 targets, and 3) Taking off and flying the aircraft a short distance to land on the center of an indicated target. Physiological measures of heart rate variability (HRV), blood pressure (BP), peripheral oxygen saturation (SpO2), electrodermal activity (EDA), and neck neuromuscular activity using electromyography (EMG) will be measured for this study. Along with questionnaires to assess hypoxic symptoms, simulator sickness, and self-perceived workload for each task

Official Title
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The Physiological Effects of Acute and Ramp Simulated Altitude Exposure During Simulated Flight Tasks

Conditions
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Altitude Hypoxia

Intervention / Treatment
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* Other: Hypoxic breathing conditions


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Meets body composition standards for the US Navy Active-duty personnel based on height and weight Normal vision/corrected to normal vision Exclusion Criteria: Respiratory Deficiencies Cardiovascular Disorders Neurological/Musculoskeletal Disorders Photosensitive Epilepsy

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Normoxic<br>Participants will complete three flight simulator tasks at a normoxic (baseline) altitude. During the flight simulator, participants will need to accomplish three tasks: 1) Maintaining an altitude of 5,000 ft of elevation while performing a mental math test, 2) Flying the aircraft through the center of a series of 7 targets, and 3) Taking off and flying the aircraft a short distance to land on the center of an indicated target. | |
| Experimental: Simulated 8,000 feet hypoxic<br>Participants will complete three flight simulator tasks at a simulated 8,000 foot altitude. During the flight simulator, participants will need to accomplish three tasks: 1) Maintaining an altitude of 5,000 ft of elevation while performing a mental math test, 2) Flying the aircraft through the center of a series of 7 targets, and 3) Taking off and flying the aircraft a short distance to land on the center of an indicated target. | Other: Hypoxic breathing conditions<br>* Participants will undergo three separate hypoxic conditions, along with a normoxic condition, simulating 8,000 foot elevation, 12,0000 foot elevation, and a ramp condition starting at 8,000 feet and then ascending to 12,000 feet.<br>|
| Experimental: Simulated 12,000 feet hypoxic<br>Participants will complete three flight simulator tasks at a simulated 12,000 foot altitude. During the flight simulator, participants will need to accomplish three tasks: 1) Maintaining an altitude of 5,000 ft of elevation while performing a mental math test, 2) Flying the aircraft through the center of a series of 7 targets, and 3) Taking off and flying the aircraft a short distance to land on the center of an indicated target. | Other: Hypoxic breathing conditions<br>* Participants will undergo three separate hypoxic conditions, along with a normoxic condition, simulating 8,000 foot elevation, 12,0000 foot elevation, and a ramp condition starting at 8,000 feet and then ascending to 12,000 feet.<br>|
| Experimental: Ramp hypoxic exposure<br>Participants will complete three flight simulator tasks in a ramp exposure breathing at simulated 8,000 feet for five minutes before ascending to simulated 12,000 feet while flying in a flight simulator. During the flight simulator, participants will need to accomplish three tasks: 1) Maintaining an altitude of 5,000 ft of elevation while performing a mental math test, 2) Flying the aircraft through the center of a series of 7 targets, and 3) Taking off and flying the aircraft a short distance to land on the center of an indicated target. | Other: Hypoxic breathing conditions<br>* Participants will undergo three separate hypoxic conditions, along with a normoxic condition, simulating 8,000 foot elevation, 12,0000 foot elevation, and a ramp condition starting at 8,000 feet and then ascending to 12,000 feet.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Flight performance | ability to perform in-flight assigned tasks | 10 minutes per each of the 4 conditions | 
| Self-perceived workload | NASA TLX survey | 1 minute to complete the survey, 3 times per condition for 4 conditions | 
| Electrodermal activity | electrical characteristics of the skin observed as changes in the resistance of the skin to a small electrical current | 10 minutes per each of the 4 conditions |