Advanced Gravitational Physiology the Lung Under High-G Acceleration

This is a study of advanced lung physiology in altered gravitational conditions, consisting of respiratory measurements in healthy volunteers during high G acceleration on a long-arm human centrifuge.

Study Overview

• Status: Completed
• Conditions: Respiratory Physiology
• Intervention / Treatment: Other: High G acceleration on a long-arm human centrifuge

Detailed Description

The lung is highly gravity-dependent - it has little actual tissue mass and deforms under its own weight. This is relevant to astronauts in space, but is actually much more broadly important to life on Earth. Every time we change our posture - for example from lying to standing - the direction in which gravity acts across the lung changes. These postural effects can become clinically important in critically ill patients. Currently there is debate in the scientific world about how gravity actually influences lung function, and how it interacts with other factors such as the anatomical structure of the airways and blood vessels of the lung. New technology developed by researchers at the University of Oxford now has the potential to help answer some of these questions. This device uses a technique called laser absorption spectroscopy to make measurements of breathing gases that are much more accurate than previous techniques - it is able to count the number of oxygen, carbon dioxide and water vapour molecules in and out while a person breathes. A non-invasive 15-minute breathing test with this technology provides information on the distributions of airflow and blood flow in the lungs, and it has been deployed successfully in the operating theatre and in intensive care units. This study aims to make comprehensive measurements of lung physiology under altered gravitational conditions and develop the technology and measurement techniques for possible future use in microgravity. This will include measurements of oxygen and carbon dioxide from the laser gas analyser (and measures of lung inhomogeneity obtained from these), lung mechanics and breathing drive.

• Study Type: Interventional
• Enrollment (Actual): 15
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • London, United Kingdom, SE11UL
    • Centre of Human and Aerospace Physiological Sciences

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 55 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• healthy volunteer who has provided informed consent

Exclusion Criteria:

• any significant medical problem, as documented extensively in the study ethics documentation.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Centrifuge study; High G acceleration on a long-arm human centrifuge	Other: High G acceleration on a long-arm human centrifuge; Gx (chest-to-back) and Gz (head-to-toe)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Lung inhomogeneity index	The lung inhomogeneity index is the standard deviation for the natural logarithm of the standardised lung compliance, equivalent to the standard deviation for the natural logarithm of the ratio between fractional lung compliance and fractional alveolar volume of the lung units. It is determined using the respiratory data obtained by molecular flow sensing using the laser gas analyser.	Determined over a 15-minute multi-breath washout at 3 G on the centrifuge

Collaborators and Investigators

• Sponsor: King's College London
• Collaborators: University of Oxford; QinetiQ Ltd; UK Space Agency
• Investigators: Principal Investigator: Thomas G Smith, King's College London

Study record dates

Study Major Dates

• Study Start (Actual): February 20, 2018
• Primary Completion (Actual): July 31, 2018
• Study Completion (Actual): July 31, 2018

Study Registration Dates

• First Submitted: February 28, 2018
• First Submitted That Met QC Criteria: March 9, 2018
• First Posted (Actual): March 13, 2018

Study Record Updates

• Last Update Posted (Actual): September 25, 2018
• Last Update Submitted That Met QC Criteria: September 24, 2018
• Last Verified: February 1, 2018

More Information

Terms related to this study

• Keywords: respiratory; physiology; gravity
• Other Study ID Numbers: SP801

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No