Orthostatic HypotensionORTHO-LBNPNCT03354234
Evaluation of the ORTHO-LBNP System
A study testing Head up tilt (HUT), Lower body negative pressure (LBNP) and Head down tilt (HDT) in people with Orthostatic Hypotension and Ischemia, run by Military Institute of Aviation Medicine at 1 site in Poland.
Trial 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… Read more about this study
- Who is it for?
- Ages 18 to 30 yearsHealthy volunteers can take part
- Conditions the study is for
- Orthostatic Hypotension, Ischemia, Hypoxia
- What is being tested?
- Head up tilt (HUT), Lower body negative pressure (LBNP) and Head down tilt (HDT)
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 46 participants
- Where
- 1 sitePoland
- Study dates
- 2 Jan 2017to 17 Feb 2018
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 30 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Pilots or cadets with flight experience
- Candidates for pilots without flight experience
- None alcohol 24 hours prior to the study
- Written informed consent
Who cannot join
- Subjects with cardiovascular disorders
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Evaluation of a Prototype System for Generating Conditions of Orthostatic Hypotension and Blood Pooling in the Lower Body
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.
Read the 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.
- Conditions
- Orthostatic Hypotension, Ischemia, Hypoxia
- Being tested
- Head up tilt (HUT), Lower body negative pressure (LBNP), Head down tilt (HDT), Tilt table, LBNP chamber
- Keywords
- Gz accelerations, Head up tilt (HUT) test, Lower body negative pressure (LBNP) method, Physiological parameters, Variable gravitational stimuli
- Medical subject headings
- Hypotension, Orthostatic, Ischemia, Hypoxia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Head up tilt (HUT)Other
Model of -Gz: HUT up to 75 degrees (maximum)
Lower body negative pressure (LBNP)Other
Model of -Gz: LBNP down to -100 mmHg (maximum)
Head down tilt (HDT)Other
Model of +Gz: HDT down to -30 degrees (maximum)
Tilt tableDevice
Range of tilt angles: -45° to +80°, rate of tilt changes: up to 45°/s
LBNP chamberDevice
Range of generated underpressure: 0 to -100 mmHg, rate of underpressure changes: up to 20 mmHg/s
| Study group | Role | What they receive |
|---|---|---|
| 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 Receives: 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 Receives: Other: Head up tilt (HUT); Other: Lower body negative pressure (LBNP); Other: Head down tilt (HDT); Device: Tilt table; Device: LBNP chamber |
What is being measured
The primary outcome is the main question the study is designed to answer.
HR
Heart rate in beats per minute
Measured: 24 minutes (scenario I)
IBI
Inter-beat interval in seconds
Measured: 24 minutes (scenario I)
SBP
Systolic blood pressure in millimeters of mercury
Measured: 24 minutes (scenario I)
DBP
Diastolic blood pressure in millimeters of mercury
Measured: 24 minutes (scenario I)
MAP
Mean arterial pressure in millimeters of mercury
Measured: 24 minutes (scenario I)
SV
Stroke volume in milliliters
Measured: 24 minutes (scenario I)
CO
Cardiac output in liters per minute
Measured: 24 minutes (scenario I)
LVET
Left ventricular ejection time in milliseconds
Measured: 24 minutes (scenario I)
RPP
Rate pressure product in millimeters of mercury
Measured: 24 minutes (scenario I)
TPR
Total peripheral resistance in medical units
Measured: 24 minutes (scenario I)
Secondary outcomes (7)
Z0_T
Base transthoracic impedance in ohms
Measured: 16 minutes (scenario II)
dZ/dt_T
First derivative of transthoracic impedance in ohms per second
Measured: 16 minutes (scenario II)
Z0_H
Base transcephalic impedance in ohms
Measured: 16 minutes (scenario II)
dZ/dt_H
First derivative of transcephalic impedance in ohms per second
Measured: 16 minutes (scenario II)
ΔC_HbO2
Changes in oxygenated hemoglobin in micromolars
Measured: 16 minutes (scenario II)
ΔC_Hb
Changes in deoxygenated hemoglobin in micromolars
Measured: 16 minutes (scenario II)
ΔC_tot
Changes in total hemoglobin in micromolars
Measured: 16 minutes (scenario II)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Nov 2017
- Study start2 Jan 2017
- Primary completion17 Feb 2018
- Study completion17 Feb 2018
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Orthostatic HypotensionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 46 participants (actual)
Sponsor and investigators
- Lead sponsor
- Military Institute of Aviation Medicine
- Sponsor type
- Other government
- 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.
- Responsible party
- Sponsor
- Investigators
- Łukasz Dziuda, DSc, PhD, Principal investigator, Military Institute of Aviation Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03354234
- Sponsor's protocol ID
- ORTHO-LBNP_01/2017
- Acronym
- ORTHO-LBNP
- Status last verified
- Mar 2026
- First submitted
- 10 Nov 2017
- Last updated
- 9 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 9 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of a Prototype System for Generating Conditions of Orthostatic Hypotension and Blood Pooling in the Lower Body
- ClinicalTrials.gov ID
- NCT03354234
- Acronym / sponsor ID
- ORTHO-LBNP / ORTHO-LBNP_01/2017
- Conditions
- Orthostatic Hypotension, Ischemia, Hypoxia
- Keywords
- Gz accelerations, Head up tilt (HUT) test, Lower body negative pressure (LBNP) method, Physiological parameters, Variable gravitational stimuli
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 46 participants (actual)
- Lead sponsor
- Military Institute of Aviation MedicineOther government
- 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.
- Study start
- 2 Jan 2017 (actual)
- Primary completion
- 17 Feb 2018 (actual)
- Study completion
- 17 Feb 2018 (actual)
- First posted
- 27 Nov 2017 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Stimuli of slowly increasing intensities | Experimental | Other: Head up tilt (HUT), Other: Lower body negative pressure (LBNP), Other: Head down tilt (HDT), Device: Tilt table, Device: LBNP chamber1. 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 |
| Stimuli of rapidly increasing intensities | Experimental | Other: Head up tilt (HUT), Other: Lower body negative pressure (LBNP), Other: Head down tilt (HDT), Device: Tilt table, Device: LBNP chamber1. 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 |
Who may qualify
- Ages
- 18 to 30 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Pilots or cadets with flight experience
- Candidates for pilots without flight experience
- None alcohol 24 hours prior to the study
- Written informed consent
Key exclusion criteria (1 listed)
- Subjects with cardiovascular disorders
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Head up tilt (HUT)Model of -Gz: HUT up to 75 degrees (maximum) | Other | Stimuli of rapidly increasing intensities, Stimuli of slowly increasing intensities |
| Lower body negative pressure (LBNP)Model of -Gz: LBNP down to -100 mmHg (maximum) | Other | Stimuli of rapidly increasing intensities, Stimuli of slowly increasing intensities |
| Head down tilt (HDT)Model of +Gz: HDT down to -30 degrees (maximum) | Other | Stimuli of rapidly increasing intensities, Stimuli of slowly increasing intensities |
| Tilt tableRange of tilt angles: -45° to +80°, rate of tilt changes: up to 45°/s | Device | Stimuli of rapidly increasing intensities, Stimuli of slowly increasing intensities |
| LBNP chamberRange of generated underpressure: 0 to -100 mmHg, rate of underpressure changes: up to 20 mmHg/s | Device | Stimuli of rapidly increasing intensities, Stimuli of slowly increasing intensities |
Primary outcome
HR
Time frame: 24 minutes (scenario I)
Heart rate in beats per minute
IBI
Time frame: 24 minutes (scenario I)
Inter-beat interval in seconds
SBP
Time frame: 24 minutes (scenario I)
Systolic blood pressure in millimeters of mercury
DBP
Time frame: 24 minutes (scenario I)
Diastolic blood pressure in millimeters of mercury
MAP
Time frame: 24 minutes (scenario I)
Mean arterial pressure in millimeters of mercury
SV
Time frame: 24 minutes (scenario I)
Stroke volume in milliliters
CO
Time frame: 24 minutes (scenario I)
Cardiac output in liters per minute
LVET
Time frame: 24 minutes (scenario I)
Left ventricular ejection time in milliseconds
RPP
Time frame: 24 minutes (scenario I)
Rate pressure product in millimeters of mercury
TPR
Time frame: 24 minutes (scenario I)
Total peripheral resistance in medical units
7 secondary outcomes
Z0_T
Time frame: 16 minutes (scenario II)
dZ/dt_T
Time frame: 16 minutes (scenario II)
Z0_H
Time frame: 16 minutes (scenario II)
dZ/dt_H
Time frame: 16 minutes (scenario II)
ΔC_HbO2
Time frame: 16 minutes (scenario II)
ΔC_Hb
Time frame: 16 minutes (scenario II)
ΔC_tot
Time frame: 16 minutes (scenario II)
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Mar 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Łukasz Dziuda, DSc, PhD principal investigator
Military Institute of Aviation Medicine
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Head up tilt (HUT), Lower body negative pressure (LBNP) and Head down tilt (HDT) in people with Orthostatic Hypotension and Ischemia, run by Military Institute of Aviation Medicine at 1 site in Poland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 9 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Poland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
HR (time frame: 24 minutes (scenario I)). The study lists 10 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Mar 2026.