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Evaluation of the ORTHO-LBNP System (ORTHO-LBNP)

Primary Purpose

Orthostatic Hypotension, Ischemia, Hypoxia

Status
Completed
Phase
Not Applicable
Locations
Poland
Study Type
Interventional
Intervention
Head up tilt (HUT)
Lower body negative pressure (LBNP)
Head down tilt (HDT)
Tilt table
LBNP chamber
Sponsored by
Military Institute of Aviation Medicine
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional basic science trial for Orthostatic Hypotension focused on measuring Gz accelerations, Head up tilt (HUT) test, Lower body negative pressure (LBNP) method, Physiological parameters, Variable gravitational stimuli

Eligibility Criteria

18 Years - 30 Years (Adult)All SexesAccepts Healthy Volunteers

Inclusion Criteria:

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

Exclusion Criteria:

  • Subjects with cardiovascular disorders

Sites / Locations

  • Military Institute of Aviation Medicine

Arms of the Study

Arm 1

Arm 2

Arm Type

Experimental

Experimental

Arm Label

Stimuli of slowly increasing intensities

Stimuli of rapidly increasing intensities

Arm Description

300-s check before the stimuli LBNP is applied stepwise with 11.1 mmHg/15 s decrement to -100 mmHg, and then this value is sustained for 120 s 180-second phase of rest between stimuli 75°-HUT (5°/s) for 120 s after a 15-s reversing of the gravity vector (-30°) 180-second phase of rest between stimuli 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 120-s check after the stimuli

120-s check before the stimuli 75°-HUT (45°/s) for 60 s after a 3-s reversing of the gravity vector (-30°) 180-second phase of rest between stimuli LBNP decreases linearly by -20 mmHg/s to -100 mmHg, and then this value is sustained for 60 s. 180 second phase of rest between stimuli 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 120-s check after the stimuli

Outcomes

Primary Outcome Measures

HR
Heart rate in beats per minute
IBI
Inter-beat interval in seconds
SBP
Systolic blood pressure in millimeters of mercury
DBP
Diastolic blood pressure in millimeters of mercury
MAP
Mean arterial pressure in millimeters of mercury
SV
Stroke volume in milliliters
CO
Cardiac output in liters per minute
LVET
Left ventricular ejection time in milliseconds
RPP
Rate pressure product in millimeters of mercury
TPR
Total peripheral resistance in medical units

Secondary Outcome Measures

Z0_T
Base transthoracic impedance in ohms
dZ/dt_T
First derivative of transthoracic impedance in ohms per second
Z0_H
Base transcephalic impedance in ohms
dZ/dt_H
First derivative of transcephalic impedance in ohms per second
ΔC_HbO2
Changes in oxygenated hemoglobin in micromolars
ΔC_Hb
Changes in deoxygenated hemoglobin in micromolars
ΔC_tot
Changes in total hemoglobin in micromolars

Full Information

First Posted
November 10, 2017
Last Updated
May 17, 2018
Sponsor
Military Institute of Aviation Medicine
Collaborators
Institute of Medical Technology and Equipment, Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Polish Air Force Academy, ETC-PZL Aerospace Industries Sp. z o.o.
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1. Study Identification

Unique Protocol Identification Number
NCT03354234
Brief Title
Evaluation of the ORTHO-LBNP System
Acronym
ORTHO-LBNP
Official Title
Evaluation of a Prototype System for Generating Conditions of Orthostatic Hypotension and Blood Pooling in the Lower Body
Study Type
Interventional

2. Study Status

Record Verification Date
May 2018
Overall Recruitment Status
Completed
Study Start Date
January 2, 2017 (Actual)
Primary Completion Date
February 17, 2018 (Actual)
Study Completion Date
February 17, 2018 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Sponsor
Name of the Sponsor
Military Institute of Aviation Medicine
Collaborators
Institute of Medical Technology and Equipment, Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Polish Air Force Academy, ETC-PZL Aerospace Industries Sp. z o.o.

4. Oversight

Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
No
Data Monitoring Committee
No

5. Study Description

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.
Detailed Description
The pilot study consists of two research scenarios, in which two different sequences of the interventions taking the form of the pre-programmed tilt and LBNP profiles are to be investigated. Scenario I is designed to initially verify the potential impact of the prototype system on the human body. For this purpose, only basic tilt and LBNP stimuli of relatively slowly increasing intensities will be used, and the group of subjects will include only subjects with flight experience. Up to 20 PAFA cadets shortly before graduation, including women and men, will be involved in the pilot study (experimental arm 1). The subjects will be healthy, aged between 20 and 30 years old. Scenario I will take almost 24 min. Scenario II is to compare subjects with and without flight experience using rapid tilt and LBNP stimuli as well as a push-pull stimulus. Up to 30 subjects including up to 15 pilots, i.e., flight school adepts shortly after graduation and/or PAFA cadets shortly before graduation, and up to 15 students of the Aviation High School in Dęblin, Poland, including women and men will be involved in the study (experimental arm 2). The subjects will be healthy, aged between 18 and 30 years old. The students of the Aviation High School will participate in the study as a reference group, without flight experience. Scenario II will take 16 min. The pilot study will be carried out in an isolated room in the presence of a physician (physiologist), a paramedic and an ORTHO-LBNP system operator. The paramedic will prepare the subject for the study by placing on his/her body electrodes and measuring sensors that will be removed after completion of the study. The subject will be asked to close his/her eyes during the tests and to place his/her hands on the rest. In order to cause the least disturbance, no conversation will be held with the subject. Only if disturbing symptoms will occur, will the subject immediately report this to the personnel. The physician will systematically be observing the subject's cardiogram, his/her HR, continuous non-invasive arterial pressure (CNAP) wave, and systolic and diastolic blood pressure (SBP and DBP, respectively) in comparison with the changing tilt of the table and negative pressure in the chamber. Any time, at the request of the subject or on the instruction of the physician, the operator will interrupt the tests. The tilt table then will return to the Trendelenburg position if interruption occur during HUT and/or LBNP stimuli, or horizontal position if interruption occur during HDT stimulus. At the same time atmospheric pressure will be resumed in the chamber.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Orthostatic Hypotension, Ischemia, Hypoxia
Keywords
Gz accelerations, Head up tilt (HUT) test, Lower body negative pressure (LBNP) method, Physiological parameters, Variable gravitational stimuli

7. Study Design

Primary Purpose
Basic Science
Study Phase
Not Applicable
Interventional Study Model
Parallel Assignment
Masking
None (Open Label)
Allocation
Non-Randomized
Enrollment
46 (Actual)

8. Arms, Groups, and Interventions

Arm Title
Stimuli of slowly increasing intensities
Arm Type
Experimental
Arm Description
300-s check before the stimuli LBNP is applied stepwise with 11.1 mmHg/15 s decrement to -100 mmHg, and then this value is sustained for 120 s 180-second phase of rest between stimuli 75°-HUT (5°/s) for 120 s after a 15-s reversing of the gravity vector (-30°) 180-second phase of rest between stimuli 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 120-s check after the stimuli
Arm Title
Stimuli of rapidly increasing intensities
Arm Type
Experimental
Arm Description
120-s check before the stimuli 75°-HUT (45°/s) for 60 s after a 3-s reversing of the gravity vector (-30°) 180-second phase of rest between stimuli LBNP decreases linearly by -20 mmHg/s to -100 mmHg, and then this value is sustained for 60 s. 180 second phase of rest between stimuli 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 120-s check after the stimuli
Intervention Type
Other
Intervention Name(s)
Head up tilt (HUT)
Intervention Description
Model of -Gz: HUT up to 75 degrees (maximum)
Intervention Type
Other
Intervention Name(s)
Lower body negative pressure (LBNP)
Intervention Description
Model of -Gz: LBNP down to -100 mmHg (maximum)
Intervention Type
Other
Intervention Name(s)
Head down tilt (HDT)
Intervention Description
Model of +Gz: HDT down to -30 degrees (maximum)
Intervention Type
Device
Intervention Name(s)
Tilt table
Intervention Description
Range of tilt angles: -45° to +80°, rate of tilt changes: up to 45°/s
Intervention Type
Device
Intervention Name(s)
LBNP chamber
Intervention Description
Range of generated underpressure: 0 to -100 mmHg, rate of underpressure changes: up to 20 mmHg/s
Primary Outcome Measure Information:
Title
HR
Description
Heart rate in beats per minute
Time Frame
24 minutes (scenario I)
Title
IBI
Description
Inter-beat interval in seconds
Time Frame
24 minutes (scenario I)
Title
SBP
Description
Systolic blood pressure in millimeters of mercury
Time Frame
24 minutes (scenario I)
Title
DBP
Description
Diastolic blood pressure in millimeters of mercury
Time Frame
24 minutes (scenario I)
Title
MAP
Description
Mean arterial pressure in millimeters of mercury
Time Frame
24 minutes (scenario I)
Title
SV
Description
Stroke volume in milliliters
Time Frame
24 minutes (scenario I)
Title
CO
Description
Cardiac output in liters per minute
Time Frame
24 minutes (scenario I)
Title
LVET
Description
Left ventricular ejection time in milliseconds
Time Frame
24 minutes (scenario I)
Title
RPP
Description
Rate pressure product in millimeters of mercury
Time Frame
24 minutes (scenario I)
Title
TPR
Description
Total peripheral resistance in medical units
Time Frame
24 minutes (scenario I)
Secondary Outcome Measure Information:
Title
Z0_T
Description
Base transthoracic impedance in ohms
Time Frame
16 minutes (scenario II)
Title
dZ/dt_T
Description
First derivative of transthoracic impedance in ohms per second
Time Frame
16 minutes (scenario II)
Title
Z0_H
Description
Base transcephalic impedance in ohms
Time Frame
16 minutes (scenario II)
Title
dZ/dt_H
Description
First derivative of transcephalic impedance in ohms per second
Time Frame
16 minutes (scenario II)
Title
ΔC_HbO2
Description
Changes in oxygenated hemoglobin in micromolars
Time Frame
16 minutes (scenario II)
Title
ΔC_Hb
Description
Changes in deoxygenated hemoglobin in micromolars
Time Frame
16 minutes (scenario II)
Title
ΔC_tot
Description
Changes in total hemoglobin in micromolars
Time Frame
16 minutes (scenario II)

10. Eligibility

Sex
All
Minimum Age & Unit of Time
18 Years
Maximum Age & Unit of Time
30 Years
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
Inclusion Criteria: Pilots or cadets with flight experience Candidates for pilots without flight experience None alcohol 24 hours prior to the study Written informed consent Exclusion Criteria: Subjects with cardiovascular disorders
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Łukasz Dziuda, DSc, PhD
Organizational Affiliation
Military Institute of Aviation Medicine
Official's Role
Principal Investigator
Facility Information:
Facility Name
Military Institute of Aviation Medicine
City
Warszawa
ZIP/Postal Code
01-755
Country
Poland

12. IPD Sharing Statement

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Evaluation of the ORTHO-LBNP System

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