Noninvasive methods research of cellular blood composition in conditions of space flight

Space technics and technology


Аuthors

Kovaleva A. A.1*, Pichulin V. S.2**, Skedina M. M.1***

1. Institute for Bio-Medical Problems of Russian Academy of Science, 76A, Horoshevskoye shosse, Moscow, 123007, Russia
2. Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, А-80, GSP-3, 125993, Russia

*e-mail: inj.ann@rambler.ru
**e-mail: start152295@yandex.ru
***e-mail: skedina@imbp.ru

Abstract

Blood is a diagnostically important biological fluid. From a physical point of view it is a suspension, where the liquid component — blood plasma and the solid component — formed elements, characterized by certain concentration, shape and size. Long duration space flight (SF) can lead to change of those parameters and some of them can be irreversible. So it is necessary to monitor the cellular composition of blood for timely preventive measures.
Work with liquid mediums under conditions of SF is complicated because of such factor as weightlessness. Invasive (i.e. with violation of skin integrity) sampling of biological material from crew members for the subsequent analysis also contains the risk of infection because an artificial closed ecosystem in a spacecraft is extremely favorable for growth and reproduction of various microorganisms.
In addition the supplies used during operation of the equipment require certain conditions of storage, have a limited shelf life and their additional delivery on board can be untimely.
All the above-stated facts prove the feasibility of non-invasive methods for the blood composition research.
For practical application of non-invasive methods allowing to assess the cellular composition of blood it is necessary to analyze such aspects as the use of this method under space flight conditions, as well as functionality and diagnostic value of the used equipment.
The purpose of this study was to consider possibilities of high-frequency Doppler Ultrasound for noninvasive research of the blood cellular composition under the SF conditions.
Currently the Ultrasound Method (US) based on the Doppler Effect is used on the ISS for the study of small (up to 1.5 mm in diameter) blood vessels. The studies carried out by authors earlier have shown that this method can be used in microgravity to determine the cellular composition of blood.
Enhancing the functionality of diagnostic equipment is achieved by improving not only the hardware but also software components. Records in digital signal processing (DSP) of the so-called "secondary effects" combined with an analysis of the amplitude spectrum and baseline (before flight) parameters of blood cellular composition allow to characterize shape, size and number of formed elements.
Simulation model of the research object is implemented with the help of MATLAB 7.0.1 environment. The model is based on the concept of representation of blood different formed elements in the form of clouds scatterers with different density, position of the mass center and average size of the particles. Block of DSP algorithm for the analysis of the amplitude spectrum is based on the sphere diffraction equation modified for set of scatterers and solved in an overdetermined system of equations.
Requirements for the hardware of ultrasound equipment were set according to the results of simulation. In particular, the minimum clock frequency of the ADC and the frequency range of ultrasound sensors are determined.
The algorithm of research execution is offered with taking account of pre-flight unit to ensure the consideration of the individual characteristics of the astronaut’s microcirculatory bloodstream. For this purpose it is necessary to assess vascular reactivity by the ultrasound method, to conduct the general blood test and then non-invasive determination of cellular composition of the blood. Research aboard manned spacecraft should be conducted in two stages: first, evaluate the type of blood flow in the smallest vessels measuring potential contribution of the "secondary effects" and only then carry out noninvasive study of the cellular composition of the blood.
The purpose of this study was to consider possibilities of high-frequency Doppler Ultrasound for noninvasive research of a cellular composition of blood under the SF conditions. Currently the Ultrasound Method (US) based on the Doppler Effect is used on the ISS for the study of small (up to 1.5 mm in diameter) blood vessels. The studies conducted by authors earlier have shown that this method can be used in microgravity to determine the cellular composition of blood. Enhancing the functionality of diagnostic equipment is achieved by improving not only the hardware but also software components. Records in digital signal processing (DSP) of the so-called "secondary effects" combined with an analysis of the amplitude spectrum and baseline (before flight) parameters of cellular composition of the blood allows to characterize shape, size and number of formed elements. Simulation model of the research object is implemented in the environment of MATLAB 7.0.1. The model is based on the concept of representation of different formed elements of blood in the form of clouds scatterers with different density, position of the center of mass and average size of the particles. Block of DSP algorithm for the analysis of the amplitude spectrum is based on the equation of diffraction on the sphere, modified for set of scatterers and solved in an overdetermined system of equations. Requirements for the hardware of ultrasound equipment were set according to the results of simulation. In particular the minimum clock frequency of the ADC and the frequency range of ultrasound sensors are determined. The algorithm of research execution is offered, consisting of pre-flight unit to ensure the consideration of the individual characteristics of the astronaut’s microcirculatory bloodstream. For this purpose it is necessary to assess vascular reactivity by the ultrasound method, to conduct the general blood test and then non-invasive determination of cellular composition of the blood. Research aboard manned spacecraft should be conducted in two stages: first, evaluate the type of blood flow in the smallest vessels measuring potential contribution of the "secondary effects" and only then carry out noninvasive study of the cellular composition of the blood.

Keywords:

analysis of blood, space flight, noninvasive methods, ultrasonic diagnostics, the mathematical model, a peak spectrum

References

  1. Nikogosjan A.E., Baevskij R.M. Zdorov'e, rabotosposobnost', bezopasnost' kosmicheskih jekipazhej (Health, performance, safety of spase crews), Moscow, Nauka, 2001, ch. 4, pp. 102-144 (501 p.).
  2. Legen'kov V.I., Kozinec G.I. Gematologija kosmicheskih poletov (Hematology of space flights), Moscow, Medicinskoe informacionnoe agentstvo, 2004, 148 p.
  3. Goncharov I.B., Kovachevich I.V., Zhernavkov Ja.F. Zdorov'e, rabotosposobnost', bezopasnost' kosmicheskih jekipazhej (Health, performance, safety of spase crews), 2001, Moscow, Nauka, 2001, ch.5, pp. 145-164 (501 p.).
  4. Skedina M.A., Kovaleva A.A., Girina M.B., Klishin G.Ju. Regionarnoe krovoobrashhenie i mikrocirkuljacija, 2008, vol. 27, no.3, pp. 58-62.
  5. Chernuh A.M., Aleksandrov P.M., Alekseev O.V. Mikrocirkuljacija (The microvasculature), Moscow, Medicina, 1975, 456 p.
  6. V.A. Kozlov, N.K. Artjushenko, O.V. Shalak, M.B. Girina, I.I. Girin, E.A. Morozova, A.A. Monastyrenko. Ul'trazvukovaja dopplerografija v ocenke sostojanija gemodinamiki v tkanjah shei, lica i polosti rta v norme i pri nekotoryh patologicheskih sostojanijah (Ultrasonic dopplerography in assessment of condition of hemodynamics in tissues of neck, face and oral cavity in norm and at some pathological conditions), St.-Petersburg, SP Minimax, 2000, 32 p.
  7. Samusev R.P., Lipchenko V.Ja. Atlas anatomii cheloveka (Human anatomy atlas), Moscow, Mir, 2004, 704 p.
  8. Kovaleva A.A., Skedina M.A., Pichulin V.S. Aviakosmicheskaja i jekologicheskaja medicina, 2009, vol. 4, pp. 45-51.
  9. Tihonov A.N., Samarskij A.A. Uravnenija matematicheskoj fiziki (Equations of mathematical physics), Moscow, MGU, 1999, 798 p.

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