Methods to Assess Self-regulatory Mechanisms of the Cardiovascular System under Simulated Hypergravity Conditions

The paper presents essential methods which enable the assessment of self-regulatory mechanisms of the cardiovascular system under simulated hypergravity conditions deployed in tests for pilots. The following testing procedures have been discussed: generating lower body negative pressure (LBNP) and positive pressure (LBPP), a head upright tilt table test (HUT), a head-down tilt (HDT) and Push-Pull mechanism. The paper also describes examples of solutions intended to simulate hypergravity conditions with particular emphasis on ORTO-LBNP, an original system used in tests for pilots and aviation candidates. The designed system is equipped with specially suited measurement modules to record physiological parameters, with a focus on cardiovascular system parameters. The developed dedicated measurement modules can be placed in one measurement cartridge, and thus can be used continuously during the test with the use of the ORTO-LBNP stand, in this way making it possible to perform both the orthostatic and LBNP test at the same time and to continuously record the physiological parameters. The paper also features preliminary results obtained during the operation of the measurement module used for the acquisition of bioimpedance signals from the thorax.

[1]  M Romuald,et al.  LBNP as useful tool for pilot candidates selection to the Polish Air Force: a preliminary study. , 2001, Journal of gravitational physiology : a journal of the International Society for Gravitational Physiology.

[2]  Stanley R. Mohler G Effects on the Pilot During Aerobatics , 1972 .

[3]  Lloyd D. Tripp,et al.  Use of Lower Body Negative Pressure as a Countermeasure to Negative Gz Acceleration , 1989 .

[4]  Marek Czerw,et al.  Tests for Pilots under Simulated Hypergravity Conditions - Technological Challenges and Tesearch Methodology , 2018, 2018 25th International Conference "Mixed Design of Integrated Circuits and System" (MIXDES).

[5]  Adam Gacek,et al.  DETERMINATION OF STROKE VOLUME OF THE VENTRICULAR ASSIST DEVICE USING BIOIMPEDANCE METHOD , 2013 .

[6]  Dariusz Wójcik,et al.  Problematyka zabezpieczenia aparatury elektromedycznej przed skutkami defibrylacji , 2014 .

[7]  A Suzumura,et al.  Effects of lower body positive pressure on muscle sympathetic nerve activity response to head-up tilt. , 2001, American journal of physiology. Regulatory, integrative and comparative physiology.

[8]  Victor A. Convertino,et al.  Sympathetic Responses to Central Hypovolemia: New Insights from Microneurographic Recordings , 2012, Front. Physio..

[9]  K K Gillingham,et al.  Visual field contraction during G stress at 13 degrees, 45 degrees, and 65 degrees seatback angles. , 1977, Aviation, space, and environmental medicine.

[10]  Ling Wang,et al.  [Changes in heart rate and blood pressure under push pull maneuver simulated on a tilt table]. , 2002, Hang tian yi xue yu yi xue gong cheng = Space medicine & medical engineering.

[11]  L. Lindblad,et al.  Effect of changes in blood volume distribution on circulatory variables and plasma renin activity in man. , 1977, Acta physiologica Scandinavica.

[12]  Tadaaki Mano,et al.  Baroreflex control of muscle sympathetic nerve activity after 120 days of 6° head-down bed rest , 2000 .

[13]  L E Lamb,et al.  Effects of lower body negative pressure on the cardiovascular system. , 1965, The American journal of cardiology.

[14]  Qi Fu,et al.  Vasoconstrictor Reserve and Sympathetic Neural Control of Orthostasis , 2004, Circulation.

[15]  Stéphane Perrey,et al.  Effect of severe hypoxia on prefrontal cortex and muscle oxygenation responses at rest and during exhaustive exercise. , 2009, Advances in experimental medicine and biology.

[16]  Marek Czerw,et al.  A multiparameter examination system to assess self-regulatory mechanisms of the cardiovascular system under simulated hypergravity conditions , 2018, 2018 Baltic URSI Symposium (URSI).

[17]  B. Westerhof,et al.  Time course analysis of baroreflex sensitivity during postural stress. , 2006, American journal of physiology. Heart and circulatory physiology.

[18]  Marek Czerw,et al.  EFFECTS OF GRADUAL ONSET +GZ ON HEMODYNAMIC PARAMETERS AND BRAIN OXYGENATION IN MILITARY PILOTS: PRELIMINARY STUDY , 2017 .

[19]  J D Grissett,et al.  Heart rate and blood pressure responses to +Gz following varied-duration -Gz. , 2000, Aviation, space, and environmental medicine.

[20]  Goodman Ls,et al.  Heart rate and blood pressure responses to +Gz following varied-duration -Gz. , 2000 .

[21]  B. Levine,et al.  Spontaneous fluctuations in cerebral blood flow: insights from extended-duration recordings in humans. , 2000, American Journal of Physiology. Heart and Circulatory Physiology.

[22]  McNaughton Gb,et al.  Visual field contraction during G stress at 13 degrees, 45 degrees, and 65 degrees seatback angles. , 1977 .

[23]  D L Eckberg,et al.  Vagal and sympathetic mechanisms in patients with orthostatic vasovagal syncope. , 1997, Circulation.

[24]  M E Safar,et al.  Microgravity and orthostatic intolerance: carotid hemodynamics and peripheral responses. , 1993, The American journal of physiology.

[25]  Marek Czerw,et al.  Evaluation of volumetric parameters of the ventricular assist device using bioimpedance method , 2012 .

[26]  X C Geng,et al.  Decreased +gz tolerance following lower body positive pressure: simulated push-pull effect. , 2001, Aviation, space, and environmental medicine.

[27]  B. J. Sjöberg,et al.  Cardiac output and blood pressure during active and passive standing. , 1996, Clinical physiology.

[28]  William H Cooke,et al.  Human cerebrovascular and autonomic rhythms during vestibular activation. , 2004, American journal of physiology. Regulatory, integrative and comparative physiology.

[29]  Krzysztof Kowalczuk,et al.  HEMODYNAMIC PARAMETERS AND BRAIN OXYGENATION IN MILITARY PILOTS AS A FUNCTION OF ACCELERATION’S DURATION AT 4G AND AT 6G: A PRELIMINARY STUDY , 2018, The Polish Journal of Aviation Medicine, Bioengineering and Psychology.

[30]  J J van Lieshout,et al.  Assessment of cardiovascular reflexes is of limited value in predicting maximal +Gz-tolerance. , 1992, Aviation, space, and environmental medicine.