Evaluation of the ORTHO-LBNP System

NCT03354234 | Completed

• 1 other identifier: ORTHO-LBNP_01/2017
• Study Type: interventional
• Target: 46
• Locations: 1 country
• Sites: 1

Brief Summary

The pilot study aims to evaluate a prototype system that enables military pilots to train under conditions of orthostatic hypotension and ischemic hypoxia. Both of these phenomena are experienced by aircraft crews of mainly highly maneuverable aircraft, and their syndromes include loss of color vision, loss of peripheral vision, blackout and finally G-induced loss of consciousness (G-LOC). A motorized tilt table to generate orthostatic (ORTHO) stress combined with an automatically controlled lower body negative pressure (LBNP) chamber to extort pooling of blood in the lower extremities has been developed in order to obtain new knowledge on counteracting the above-mentioned effects and minimizing the risk of their occurrence. This will help optimize the selection procedures of candidates with the best physiological predispositions to work as military pilots. The system is equipped with modules for monitoring biomedical parameters of a subject, including cerebral oxygenation, which ensures their safety and provides a source of data for performing advanced analyses. The ORTHO-LBNP system has been subjected to comprehensive laboratory tests and after a successful testing is ready for a pilot study involving pilots and/or cadets of the Polish Air Force Academy (PAFA). It is anticipated that new indicators will be proposed to enable an objective assessment of the predispositions to pursue a military pilot career. The prototype system can be easily adaptable to the needs of clinical and sports medicine as well as rehabilitation.

Conditions

Orthostatic Hypotension; Ischemia; Hypoxia

Keywords

Gz accelerations; Head up tilt (HUT) test; Lower body negative pressure (LBNP) method; Physiological parameters; Variable gravitational stimuli

Outcome Measures

Primary Outcomes (10)

• HR

  Heart rate in beats per minute

  24 minutes (scenario I)

• IBI

  Inter-beat interval in seconds

  24 minutes (scenario I)

• SBP

  Systolic blood pressure in millimeters of mercury

  24 minutes (scenario I)

• DBP

  Diastolic blood pressure in millimeters of mercury

  24 minutes (scenario I)

• MAP

  Mean arterial pressure in millimeters of mercury

  24 minutes (scenario I)

• SV

  Stroke volume in milliliters

  24 minutes (scenario I)

• CO

  Cardiac output in liters per minute

  24 minutes (scenario I)

• LVET

  Left ventricular ejection time in milliseconds

  24 minutes (scenario I)

• RPP

  Rate pressure product in millimeters of mercury

  24 minutes (scenario I)

• TPR

  Total peripheral resistance in medical units

  24 minutes (scenario I)

Secondary Outcomes (7)

• Z0_T

  16 minutes (scenario II)

• dZ/dt_T

  16 minutes (scenario II)

• Z0_H

  16 minutes (scenario II)

• dZ/dt_H

  16 minutes (scenario II)

• ΔC_HbO2

  16 minutes (scenario II)

Study Arms (2)

Stimuli of slowly increasing intensities

EXPERIMENTAL

1. 300-s check before the stimuli 2. LBNP is applied stepwise with 11.1 mmHg/15 s decrement to -100 mmHg, and then this value is sustained for 120 s 3. 180-second phase of rest between stimuli 4. 75°-HUT (5°/s) for 120 s after a 15-s reversing of the gravity vector (-30°) 5. 180-second phase of rest between stimuli 6. 75°-HUT (5°/s) accompanied by an exposure to an LBNP of -60 mmHg increased linearly by -4 mmHg/s, and then this value is sustained for 120 s during HUT 7. 120-s check after the stimuli

Other: Head up tilt (HUT); Other: Lower body negative pressure (LBNP); Other: Head down tilt (HDT); Device: Tilt table; Device: LBNP chamber

Stimuli of rapidly increasing intensities

EXPERIMENTAL

1. 120-s check before the stimuli 2. 75°-HUT (45°/s) for 60 s after a 3-s reversing of the gravity vector (-30°) 3. 180-second phase of rest between stimuli 4. LBNP decreases linearly by -20 mmHg/s to -100 mmHg, and then this value is sustained for 60 s. 5. 180 second phase of rest between stimuli 6. push-pull, i.e., 3 x 75°-HUT (45°/s) preceded by -30°-HDT (45°/s) and accompanied by an exposure to an LBNP of -60 mmHg decreased linearly by -20 mmHg/s, and then this value is sustained for 30 s during HUT 7. 120-s check after the stimuli

Other: Head up tilt (HUT); Other: Lower body negative pressure (LBNP); Other: Head down tilt (HDT); Device: Tilt table; Device: LBNP chamber

Interventions

Head up tilt (HUT) OTHER

Model of -Gz: HUT up to 75 degrees (maximum)

Stimuli of rapidly increasing intensities; Stimuli of slowly increasing intensities

Lower body negative pressure (LBNP) OTHER

Model of -Gz: LBNP down to -100 mmHg (maximum)

Stimuli of rapidly increasing intensities; Stimuli of slowly increasing intensities

Head down tilt (HDT) OTHER

Model of +Gz: HDT down to -30 degrees (maximum)

Stimuli of rapidly increasing intensities; Stimuli of slowly increasing intensities

Tilt table DEVICE

Range of tilt angles: -45° to +80°, rate of tilt changes: up to 45°/s

Stimuli of rapidly increasing intensities; Stimuli of slowly increasing intensities

LBNP chamber DEVICE

Range of generated underpressure: 0 to -100 mmHg, rate of underpressure changes: up to 20 mmHg/s

Stimuli of rapidly increasing intensities; Stimuli of slowly increasing intensities

Eligibility Criteria

• Age: 18 Years - 30 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Pilots or cadets with flight experience
• Candidates for pilots without flight experience
• None alcohol 24 hours prior to the study
• Written informed consent

You may not qualify if:

• Subjects with cardiovascular disorders

Sponsors & Collaborators

• Military Institute of Aviation Medicine: lead
• Institute of Medical Technology and Equipment: collaborator
• Polish Air Force Academy: collaborator
• ETC-PZL Aerospace Industries Sp. z o.o.: collaborator
• Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences: collaborator

Study Sites (1)

Military Institute of Aviation Medicine

Warsaw, 01-755, Poland

Location

MeSH Terms

Conditions

Hypotension, Orthostatic; Ischemia; Hypoxia

Interventions

Lower Body Negative Pressure; Head-Down Tilt; Tilt-Table Test

Condition Hierarchy (Ancestors)

Orthostatic Intolerance; Primary Dysautonomias; Autonomic Nervous System Diseases; Nervous System Diseases; Hypotension; Vascular Diseases; Cardiovascular Diseases; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Signs and Symptoms, Respiratory; Signs and Symptoms

Intervention Hierarchy (Ancestors)

Decompression; Therapeutics; Posture; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Diagnostic Techniques, Cardiovascular; Diagnostic Techniques and Procedures; Diagnosis

Study Officials

• Łukasz Dziuda, DSc, PhD

  Military Institute of Aviation Medicine

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER GOV
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 10, 2017
• First Posted: November 27, 2017
• Study Start: January 2, 2017
• Primary Completion: February 17, 2018
• Study Completion: February 17, 2018
• Last Updated: March 9, 2026

Record last verified: 2026-03

Locations

PL (1)