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. 2018 May 17;8(1):7793.
doi: 10.1038/s41598-018-26173-2.

Development and evaluation of a novel system for inducing orthostatic challenge by tilt tests and lower body negative pressure

Łukasz Dziuda  1 , Mariusz Krej  2 , Maciej Śmietanowski  3 , Aleksander Sobotnicki  4 , Mariusz Sobiech  4 , Piotr Kwaśny  5 , Anna Brzozowska  5 , Paulina Baran  2 , Krzysztof Kowalczuk  6 , Franciszek W Skibniewski  2
Affiliations

Development and evaluation of a novel system for inducing orthostatic challenge by tilt tests and lower body negative pressure

Łukasz Dziuda et al. Sci Rep. .

Abstract

Lower body negative pressure (LBNP) is a method derived from space medicine, which in recent years has been increasingly used by clinicians to assess the efficiency of the cardiovascular regulatory mechanisms. LBNP with combined tilt testing is considered as an effective form of training to prevent orthostatic intolerance. We have developed a prototype system comprising a tilt table and LBNP chamber, and tested it in the context of the feasibility of the device for assessing the pilots' efficiency. The table allows for controlled tilting in the range from -45 to +80° at the maximum change rate of 45°/s. The LBNP value can smoothly be adjusted down to -100 mmHg at up to 20 mmHg/s. 17 subjects took part in the pilot study. A 24-minute scenario included -100 mmHg supine LBNP, head up tilt (HUT) and -60 mmHg LBNP associated with HUT, separated by resting phases. The most noticeable changes were observed in stroke volume (SV). During supine LBNP, HUT and the combined stimulus, a decrease of the SV value by 20%, 40% and below 50%, respectively, were detected. The proposed system can map any pre-programed tilt and LBNP profiles, and the pilot study confirmed the efficiency of performing experimental procedures.

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Conflict of interest statement

The authors declare no competing interests.

Figures

Figure 1
Figure 1
Considered models of the tilt table construction.
Figure 2
Figure 2
Trajectories of the body on the tilt table during (a) HUT and (b) HDT tests.
Figure 3
Figure 3
Strength analysis of the chamber based on an (a) Al frame, 1 transverse beam, 30° slope, PC inserts, 5 mm thick, (b) Al frame, 2 transverse beams, 45° slope, PC inserts, 6 mm thick, (c) thermoformed PC sheet, 8 mm thick and (d) thermoformed corrugated PC sheet, 6 mm thick.
Figure 4
Figure 4
Example of an original recording: table tilt, LBNP profile, ECG signal, CNAP wave, and traces of the physiological parameters extracted from the ECG and CNAP signals in the subsequent phases of the pilot study.
Figure 5
Figure 5
Absolute and relative changes in HR, IBI, SBP, DBP, MAP, SV, CO, LVET, RPP and TPR in the subsequent phases of the pilot study. Asterisks indicate the statistical significance (p ≤ 0.05).
Figure 6
Figure 6
Medical monitoring subsystem: the (a) block diagram, (b) main module box by the Institute of Medical Technology and Equipment, Poland, (c) in-house-designed module box by the Nałęcz Institute of Biocybernetics and Biomedical Engineering of the Polish Academy of Sciences.
Figure 7
Figure 7
Photographs of the prototype system: a (a) subject during an examination, the (b) open LBNP chamber with the footboard, (c) optionally mounted saddle.
See this image and copyright information in PMC

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References

    1. Voge VM. Acceleration forces on the human subject. Aviat. Space Environ. Med. 1980;9:970–980. - PubMed
    1. Creer, B. Y., Smedal, H. A. & Wingrove, R. C. Centrifuge study of pilot tolerance to acceleration and the effects of acceleration on pilot performance. NASA Technical Note D-337https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19980223621.pdf (1960).
    1. Stevens PM, Lamb LE. Effects of lower body negative pressure on the cardiovascular system. Am. J. Cardiol. 1965;16:506–515. doi: 10.1016/0002-9149(65)90027-5. - DOI - PubMed
    1. Gilbert CA, Stevens PM. Forearm vascular responses to lower body negative pressure and orthostasis. J. Appl. Physiol. 1966;21:1265–1272. doi: 10.1152/jappl.1966.21.4.1265. - DOI - PubMed
    1. Wolthuis RA, Bergman SA, Nicogossian AE. Physiological effects of locally applied reduced pressure in man. Physiol. Rev. 1974;54:566–595. doi: 10.1152/physrev.1974.54.3.566. - DOI - PubMed

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