Problems associated with creating special software for simulating of human physiological responses to dynamic accelerations
Under extreme accelerations, human physiological mechanisms cannot provide adequate circulation. Special methods and devices protecting pilot’s brain and eye functionality have been proposed but their efficiency is individual and depends on pilot’s skills. Currently, the lonely technology to safely...
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pp_isofts_kiev_ua-article-6042024-04-27T17:04:37Z Problems associated with creating special software for simulating of human physiological responses to dynamic accelerations Проблеми створення спеціального програмного забезпечення для моделювання фізіологічних реакцій людини на динамічні прискорення Grygoryan, R.D. human extreme physiology; quantitative models; simulator; training; information technology UDC 517.958:57 +519.711.3 + 612.51.001 екстремальна фізіологія людини; кількісні моделі; тренажер; навчання; інформаційна технологія УДК 517.958:57 +519.711.3 + 612.51.001 Under extreme accelerations, human physiological mechanisms cannot provide adequate circulation. Special methods and devices protecting pilot’s brain and eye functionality have been proposed but their efficiency is individual and depends on pilot’s skills. Currently, the lonely technology to safely acquire and test the necessary skills is based on use of special centrifuges. However, lack of adequate data about physiological and biomechanical events are two main causes worsening the training results. Special computer simulators, capable to model and visualize the main mechanical and physiological effects occurring under dynamic accelerations, could increase the effectiveness of future pilot’s training process. This publication aims to define fundamental problems concerned with creating the required software. There exist two main groups of problems. The first group is concerned with the necessity to create basic mathematical models quantitatively describing both the physiological events and effects induced by protective maneuvers. Here special logical procedures, individualizing the basic physiological models, have to be proposed. The second group of problems is predominantly technical and associated with the necessity of special user interface (SUI) development. SUI must be subdivided into two functional sections – one for preparing a single computer experiment (simulation), and another – for analyzing the results of simulation. An experiment preparation includes the following events: i) a preliminary tuning of models according to biometrical data; ii) a setting of acceleration profile; iii) a choosing of protective algorithms and tools (or without protections); iv) a choosing of forms for results storage. Graphs presenting the dynamics of input and output variables are the main forms while the table forms are also included. The user (trainer or trainee) will be able to retrieve from the memory graphs of previous simulations to compare the effectiveness of additional protective elements. The software must be autonomic for the Windows platform.Prombles in programming 2024; 1: 30-37 Під час екстремальних прискореннях фізіологічні механізми людини не можуть забезпечити належний кровообіг. Були запропоновані методи та пристрої для захисту мозку та очей пілота. Їхня ефективність індивідуальна і залежить від навичок пілота. Наразі єдина технологія безпечного отримання та перевірки необхідних навичок базується на використанні спеціальних центрифуг. Однак відсутність адекватних даних про фізіологічні та біомеханічні події є двома основними причинами погіршення результатів тренувань. Підвищити ефективність процесу підготовки майбутнього пілота могли б спеціальні комп’ютерні тренажери, здатні моделювати та візуалізувати основні механічні та фізіологічні ефекти, що виникають у випадку динамічних прискорень. Ця публікація має на меті визначити фундаментальні проблеми, пов’язані зі створенням необхідного програмного забезпечення. Існує дві основні групи проблем. Перша група пов’язана зі створенням базових математичних моделей, які кількісно описують фізіологічні події та ефекти, спричинені захисними маневрами. Тут повинні бути запропоновані спеціальні логічні процедури, що індивідуалізують основні фізіологічні моделі. Друга група проблем має переважно технічний характер і пов’язана з необхідністю розробки спеціального інтерфейсу користувача (СІК). СІК необхідно розділити на дві функціональні частини – першу для підготовки одного комп’ютерного експерименту (моделювання), а другу – для аналізу результатів моделювання. Підготовка експерименту включає наступні заходи: i) попереднє налаштування моделей за біометричними даними; ii) налаштування профілю прискорення; iii) вибір захисних алгоритмів та інструментів (або без захисту); iv) вибір форм для зберігання результатів. Графіки, що представляють динаміку вхідних і вихідних змінних, є основними формами, а табличні форми також включені. Користувач (тренер або стажер) зможе отримати з пам’яті графіки попередніх симуляцій для порівняння ефективності додаткових захисних елементів. Програмне забезпечення має бути автономним для платформи Windows.Prombles in programming 2024; 1: 30-37 Інститут програмних систем НАН України 2024-04-01 Article Article application/pdf https://pp.isofts.kiev.ua/index.php/ojs1/article/view/604 10.15407/pp2024.01.030 PROBLEMS IN PROGRAMMING; No 1 (2024); 30-37 ПРОБЛЕМЫ ПРОГРАММИРОВАНИЯ; No 1 (2024); 30-37 ПРОБЛЕМИ ПРОГРАМУВАННЯ; No 1 (2024); 30-37 1727-4907 10.15407/pp2024.01 en https://pp.isofts.kiev.ua/index.php/ojs1/article/view/604/654 Copyright (c) 2024 PROBLEMS IN PROGRAMMING |
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human extreme physiology quantitative models simulator training information technology UDC 517.958:57 +519.711.3 + 612.51.001 |
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human extreme physiology quantitative models simulator training information technology UDC 517.958:57 +519.711.3 + 612.51.001 Grygoryan, R.D. Problems associated with creating special software for simulating of human physiological responses to dynamic accelerations |
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human extreme physiology quantitative models simulator training information technology UDC 517.958:57 +519.711.3 + 612.51.001 екстремальна фізіологія людини кількісні моделі тренажер навчання інформаційна технологія УДК 517.958:57 +519.711.3 + 612.51.001 |
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Grygoryan, R.D. |
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Grygoryan, R.D. |
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Grygoryan, R.D. |
| title |
Problems associated with creating special software for simulating of human physiological responses to dynamic accelerations |
| title_short |
Problems associated with creating special software for simulating of human physiological responses to dynamic accelerations |
| title_full |
Problems associated with creating special software for simulating of human physiological responses to dynamic accelerations |
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Problems associated with creating special software for simulating of human physiological responses to dynamic accelerations |
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Problems associated with creating special software for simulating of human physiological responses to dynamic accelerations |
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problems associated with creating special software for simulating of human physiological responses to dynamic accelerations |
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Проблеми створення спеціального програмного забезпечення для моделювання фізіологічних реакцій людини на динамічні прискорення |
| description |
Under extreme accelerations, human physiological mechanisms cannot provide adequate circulation. Special methods and devices protecting pilot’s brain and eye functionality have been proposed but their efficiency is individual and depends on pilot’s skills. Currently, the lonely technology to safely acquire and test the necessary skills is based on use of special centrifuges. However, lack of adequate data about physiological and biomechanical events are two main causes worsening the training results. Special computer simulators, capable to model and visualize the main mechanical and physiological effects occurring under dynamic accelerations, could increase the effectiveness of future pilot’s training process. This publication aims to define fundamental problems concerned with creating the required software. There exist two main groups of problems. The first group is concerned with the necessity to create basic mathematical models quantitatively describing both the physiological events and effects induced by protective maneuvers. Here special logical procedures, individualizing the basic physiological models, have to be proposed. The second group of problems is predominantly technical and associated with the necessity of special user interface (SUI) development. SUI must be subdivided into two functional sections – one for preparing a single computer experiment (simulation), and another – for analyzing the results of simulation. An experiment preparation includes the following events: i) a preliminary tuning of models according to biometrical data; ii) a setting of acceleration profile; iii) a choosing of protective algorithms and tools (or without protections); iv) a choosing of forms for results storage. Graphs presenting the dynamics of input and output variables are the main forms while the table forms are also included. The user (trainer or trainee) will be able to retrieve from the memory graphs of previous simulations to compare the effectiveness of additional protective elements. The software must be autonomic for the Windows platform.Prombles in programming 2024; 1: 30-37 |
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Інститут програмних систем НАН України |
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2024 |
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Прикладне програмне забезпечення
30
УДК 517.958:57 +519.711.3 + 612.51.001 http://doi.org/10.15407/pp2024.01.30
R.D. Grygoryan
PROBLEMS ASSOCIATED WITH CREATING SPECIAL
SOFTWARE FOR SIMULATING OF HUMAN PHYSIOLOGICAL
RESPONSES TO DYNAMIC zG ACCELERATIONS
Under extreme accelerations, human physiological mechanisms cannot provide adequate circulation. Special
methods and devices protecting pilot’s brain and eye functionality have been proposed but their efficiency is
individual and depends on pilot’s skills. Currently, the lonely technology to safely acquire and test the nec-
essary skills is based on use of special centrifuges. However, lack of adequate data about physiological and
biomechanical events are two main causes worsening the training results. Special computer simulators, ca-
pable to model and visualize the main mechanical and physiological effects occurring under dynamic accel-
erations, could increase the effectiveness of future pilot’s training process. This publication aims to define
fundamental problems concerned with creating the required software. There exist two main groups of prob-
lems. The first group is concerned with the necessity to create basic mathematical models quantitatively de-
scribing both the physiological events and effects induced by protective maneuvers. Here special logical
procedures, individualizing the basic physiological models, have to be proposed. The second group of prob-
lems is predominantly technical and associated with the necessity of special user interface (SUI) develop-
ment. SUI must be subdivided into two functional sections – one for preparing a single computer experiment
(simulation), and another – for analyzing the results of simulation. An experiment preparation includes the
following events: i) a preliminary tuning of models according to biometrical data; ii) a setting of accelera-
tion profile; iii) a choosing of protective algorithms and tools (or without protections); iv) a choosing of
forms for results storage. Graphs presenting the dynamics of input and output variables are the main forms
while the table forms are also included. The user (trainer or trainee) will be able to retrieve from the
memory graphs of previous simulations to compare the effectiveness of additional protective elements. The
software must be autonomic for the Windows platform.
Keywords: human extreme physiology, quantitative models, simulator, training, information technology.
Introduction
Maneuvers on modern fighter aircraft
are associated with rapid altering and often
highly sustained extreme accelerations [1-3].
Both physiological [4-9] and biotechnical [10-
12] problems that arose in parallel with an
increase in military aircraft's maneuverability
have been properly investigated [4-18]. Hu-
man physiology evolutionarily adapted to the
one g Earth environment, cannot provide ade-
quate functioning of the brain and eyes of a
sitting person. Two of these organs, very sen-
sitive to oxygen and glucose supply, suffer in
parallel with the decreasing of their input
blood pressure. Under accelerations, the hy-
drostatic pressure proportional to the accelera-
tion value expands the vascular wall, accumu-
lating greater blood volume. The altered pres-
sure gradients do not provide the necessary
circulation at the cardiovascular scale. Accel-
erations also alter the ventilation-perfusion
ratio in lungs [13,14].
Most critical are positive (+Gz) accel-
erations acting in the direction of head-legs,
or negative (-Gz) accelerations acting in the
opposite direction [4-6]. In terminal zones
(brain, eyes), the lowered circulation causes
oxygen lack and worsens the pilot’s vision
and consciousness [9,12]. Under -Gz, the ele-
vated local blood pressure in the eyes and
brain causes rupture of microscopic vessels
and hemorrhages. Both the value of Gz and
the gradient of acceleration change play an
essential role in these events.
Under relatively slow (0.1-0.4 g/sec)
linearly increasing +Gz accelerations, a mean
healthy person not using artificial protections
is operable for approximately +4Gz accelera-
tions [11]. Further elevation of the G-load
causes the G-lock phenomenon usually disap-
pearing after a break [2,6,8].
Modern fighter aircrafts (like F16,
F35, and others) can provide acceleration gra-
© R.D. Grygoryan, 2024
ISSN 1727-4907. Проблеми програмування. 2024. №1
Прикладне програмне забезпечення
31
dients exceeding 2 g/sec. This requires special
protection algorithms and devices. Currently,
typical protection algorithms include the use
of special pneumatic or water-augmented an-
ti-G suits, muscle stress, as well as breathing
with a positive pressure air [1,11,17]. The
adaptive protection algorithms combining
multiple methods depending on the dynamics
of accelerations are the most effective. So, a
technology helping to optimally combine pro-
tective methods and tools is encouraged.
Traditionally, empiric research on cen-
trifuges is the main way for inventing more
effective protections [1,5,6-8]. As was
demonstrated in [18-20], mathematical mod-
els realized as special software provided by
additional ways to maximize the individual
resistance of a pilot to the negative effects of
accelerations. The experience in this special
area is a basis for creating an advanced ver-
sion of such software.
This article defines the main require-
ments for future software and ways for its
creation.
Main functional blocks
of the future software
1. The main blocks of models
The main mathematical models conven-
tionally divided into two groups are shown in
Fig.1.
Figure1. Mathematical models and procedures to be used in the future software.
Fig.1 indicates that there should be cre-
ated two blocks of quantitative models: mod-
els of physiological mechanisms; and models
representing environmental physical factors
modulating local, regional, or total hemody-
namics.
Models of physiological mechanisms
should quantitatively describe the dynamics
of blood pressures, volumes, and flows of a
sitting person under altering blood hydrostatic
pressure. Important is that the model must
describe the main neural-hormonal influences
(modulations) of characteristics, involved in
descriptions of both the cardiac pump func-
tion and vascular tonus.
A correct understanding of the student
(future pilot) of the essence of physiological
processes during flight overloads can play an
essential role in the acquisition of profession-
al skills. Usually, empirical technologies for
training pilots to counteract the undesirable
effects of g-forces focus on two main circum-
stances caused by extreme accelerations: 1)
narrowing of the field of peripheral vision or
loss of vision; 2) loss of consciousness as an
extreme manifestation (G-lock). These phe-
nomena, caused by a deterioration of the eyes
and brain oxygen supply, are only manifesta-
tions of more extensive changes in human
hemodynamics. However, empirics provide
very scant information about these hemody-
namic processes. The matter is that standard
measurements are limited to monitoring the
dynamics of heart rate (HR) and blood pres-
sure. The shift in HR can be provided by
multiple mechanisms. Several of them are
Прикладне програмне забезпечення
32
known as physiological regulators reacting to
a drop in pressure in the reflexogenic zones of
the arterial tree. Other regulators can be large-
ly activated by the mechanical stretching of
body structures. Therefore, the proper model
must describe the effects of both mechanisms.
Finally, the specific dynamics of blood pres-
sure are associated with movements and re-
distribution of significant volumes of blood
under the influence of increased hydrostatic
pressure.
The quantitative mathematical model of
human hemodynamics is the single method
that can illustrate the cause-and-effect rela-
tionships of developing dynamic events. It
should be emphasized that the maximum ad-
ditive effect of protective agents can only
occur when each additional protective agent is
activated at the right time. It can be detected
using the mathematical model we create.
To increase the visibility of the protec-
tive effect, a special simulation mode will be
provided when the physiological regulators
are turned off. This simulation will reveal
what could happen to hemodynamics if the
body is late to respond to the mechanical
movements of blood in the human body.
In Fig. 1, the second group of models
collects models quantitatively describing the
influences of external mechanical dynamic
forces on local, regional, or total hemodynam-
ics. Namely, these models describe hemody-
namic modulations of each protective tool and
algorithm.
In the right part of the Fig. 1, two addi-
tional options are indicated. The bottom-
located rectangle accentuates the fact that a
special model will be proposed for the simula-
tion of acceleration profiles. At last, the upper
rectangle indicates that special logic and
mathematic approximations must be proposed
to individualize the physiology model using
anthropometrics and the sex of the person to
be tested (simulated).
At last, the software must provide a
computer experiment (simulation) and record-
ing of its results as a special experiment pro-
tocol (SEP). Personalized records of SEPs can
be accumulated in special files for their re-
producing and deep analysis. The latter must
provide an option for comparing of chosen
variables for at least two experiments. These
basic requirements mainly determine the
software architecture.
The future software is intended to be
autonomous Windows oriented. Exe module
called “Accel.exe”. The success of software
depends on two main factors: 1) how much it
is needed; and 2) how practical is its user in-
terface (UI). In our particular case, UI must be
oriented both to student pilots and their train-
ers-instructors. Therefore, icons intuitively
appointing procedures needed to be activated
for the program’s preparation before execut-
ing is desirable. In addition, special icons in-
tuitively appointing procedures for visualizing
and analysis of simulation results are encour-
aged. Fig.2 below indicates the main proce-
dures necessary for preparing and executing a
single computer experiment (simulation), and
that have to be provided by a UI.
Fig.2. Procedures that are necessary for pre-
paring and executing a single computer exper-
iment (simulation), and that have to be pro-
vided by a special user interface (UI).
2. Main functional blocks of UI
By downloading the future autonomous
“Accel.exe”, the user will have a core (basic
version) of the quantitative model that has to
be specially tuned for providing a single com-
puter experiment (simulation). The tuning
operations, provided by the UI, are intended
to transform the basic version of complex
models to a person-oriented model possessing
a set of constants characterizing both physio-
logical and environmental parameters.
Personal sensitivity of nervous regula-
tors can vary in a wide range. There is no
strain recommendation for associating the
sensitivity coefficients with anthropometric
data. At the same time, it is known that some
tests (in particular, the postural test) can help
Прикладне програмне забезпечення
33
us to approximately individualize the heart
rate’s neurogenic sensitivity. During the pro-
ject execution, several ideas have to be algo-
rithmically realized and tested.
Mathematical models
The principle is to differentiate two
blocks of mathematical models. The first
block describes human hemodynamics under
varying hydrostatic pressures and extravascu-
lar pressures. The model does take into ac-
count the main effects of physiological con-
trol mechanisms that normally provide acute
cardiovascular responses to dynamic accelera-
tions.
1. The background of the physiological
models
The human cardiovascular system
(CVS) must be presented in the model as a
structure combined with two subunits. The
first subunit represents the vascular bed as a
net of arterial and venous compartments each
localized at different distances from the foot
level. Every vascular compartment will have
its fixed initial parameters (rigidity )0(iD ,
unstressed volume )0(iU , and resistance
)0(ir ). Current (dynamic) values of these
variables will be calculated taking into ac-
count increments provided by nervous-
endocrine regulators:
,)0()( =
j
jii UUtU (1)
,)0()( =
j
jii DDtD (2)
))(),(()0()( tUtDrtr iiii = . (3)
The principal is to model the influ-
ences of gravitational and extravascular me-
chanical forces on local output blood flows
)(tqi :
)(/))]()()((
))()()([()(
111 trtPtPtP
tPtPtPtq
i
E
i
G
ii
E
i
G
iii
+++ ++
−++=
, (4)
where the gravitational component )(tPG
i is
calculated using the distance of the vascular
compartment from the foot ih , the current
value of acceleration )(tGz , and the angle
)(ti between acceleration vector and body
vascular compartment.
)(sin)()( ttGhtP izi
G
i = . (4.1)
As observation intervals under simu-
lating of acceleration events are limited by
minutes, the total blood volume .constV =
Shifts of compartmental ( )(tVi ) and regional
blood volumes appear due to alterations of
compartmental input-output flows:
).()(
1
tqtq
dt
dV
ii
i −=
−
(5)
Arterial baroreceptor reflexes are con-
sidered to be the main physiological mecha-
nisms counteracting to lowering of perfusion
pressure in the brain [67]. In a rigid cranium,
the normal extravascular pressure is slightly
subatmospheric. +Gz accelerations, especially
in non-collapsible venous sinuses, aggravate
the negative pressure. These biomechanical
factors, lowering the venous return from a cra-
nial basin to the heart, play a specific counter-
acting role against the gravitational decrease of
brain circulation. Besides, within 50 mm Hg
alterations of brain perfusion pressure, auto-
nomic nervous mechanisms provide a practical
constancy of the summary brain flow. Addi-
tional protective effects are provided by a re-
flector mechanism activated due to the lower-
ing of intravascular pressure in the circle of
Willis. This effect was first shown in [78].
Practically always real military fighter
missions are accompanied by mental stress
and delivery of catecholamines that addition-
ally mobilize CVS. Empiric observations
have also shown a phenomenon of heart rate
extreme increase despite essentially elevated
blood pressure in the aortic arch. This phe-
nomenon can be explained and modeled in the
assumption that under high levels of accelera-
tion, the mechanical stress of muscles origi-
nates high proprioception capable of compen-
sating the depressor influence of the aortic
arch baroreflex.
2. The background of models describing
the physical environment
Fighter pilots, functioning in a highly
dynamic environment, are provided by artifi-
cial specifically acting biomechanical protec-
Прикладне програмне забезпечення
34
tive tools and methods. Standardly, they in-
clude: i) a pilot’s chair with a declined to
horizon under angle A supine; ii) anti-G suit;
iii) a helmet provided by a device for breath-
ing under positive pressure. To this list can be
added special technics for tensing the muscles
of the legs and abdominals.
So, to simulate the protective effects
of the artificial tools, additional equations
describing the transformation of external bio-
mechanical forces into the body’s regional
vasculature are required. Simulation algo-
rithms must provide applications of a chosen
acceleration profile for every combination of
protections. To demonstrate protection ef-
fects, as well as to compare the effects of eve-
ry single method, it desirable is to have two
special model versions. The first one illus-
trates hemodynamics under accelerations with
switched-of physiological regulators. The
second version does simulate hemodynamic
responses of a person with the normal func-
tioning of the physiological controllers of
CVS. There are three specific ways to coun-
teract extreme increases in vascular volume:
1) increasing the vascular rigidity; 2) decreas-
ing the non-stressed volume; 3) elevating the
extravascular pressure.
The first two ways are incorporated
into physiological reflector regulators. The
third opportunity can be used without or with
the application of artificial devices. In the first
case, the person being under acceleration
forces can consciously increase the tension in
the muscles of the legs and abdominals. When
additional efforts to exhale with a closed air-
way have been provided, the protective effect
is higher.
Constructively, anti-G suits can be
with pneumatic or water-filled chambers. The
standard anti-G suit is sectional (for body
sections of the abdomen, thighs, and shins).
Versions of suits containing special sections
for creating certain supra-atmospheric pres-
sure at the chest are also proposed [6]. In gen-
eral, these suits do resist the accumulation of
local blood volumes. So, in the background of
+Gz, a pumping of pressured air into the anti-
G suit lowers the sectional blood volume. The
matter is how to model these protective ef-
fects.
In equation (4) above, there is a varia-
ble )(tPE
i which presents local extravascular
pressure. Certainly, leg muscles, abdomen, or
thoracic cavities will have their transfer coef-
ficients for transmitting the applied external
pressure ( )(tPE ) to the depth of blood vessels.
In (4), summary extravascular pressure should
be calculated as:
)()( tPktP Ei
E
i = . (4.2)
3. Models describing input loads
The model to be used in the future
software will calculate human hemodynamic
responses to two different types of input dy-
namic loads. During simulations of the pilot
who is not using protections, the dynamics of
accelerations are the lonely input loads initiat-
ing alterations of the normal physiology of
circulation and causing reflector responses.
Protection activation should be considered as
the second type of input load. Real flight ma-
neuvers, especially combat maneuvers, occur
under combined input loads. To estimate the
separate effects of each input load, it is neces-
sary to design algorithms providing arbitrary
combinations of both types of input loads.
Below, supposing the value of A to be con-
stant, the first and the second types of input
loads are consequentially considered.
The initial hemodynamic alterations depend
on both acceleration gradients and amplitude.
So, to correctly simulate these biomechanical
events, our software must include a model,
describing accelerations dynamics. It is
planned to provide the following acceleration
profiles: a) a linear with a given gradient a
and of duration; b) a linear with a further
transforming to a constant (plateau) of du-
ration; c) a trapezoidal with given parameters;
d) a special profile for imitating the known
“push-pull” effect; e) arbitrary constructing
by a user profile. Formalisms for modeling
these profiles are described below.
The first profile is presented as:
−
=
ssg
s
ttttA
tt
ta
),(
,0
)( , (6)
where st - is start time of the increasing
of acceleration with a gradient of gA .
Прикладне програмне забезпечення
35
The second profile is presented as:
+
−
=
Tttta
tttttA
tt
ta
ppm
pssg
s
,
),(
,0
)( , (7)
where pt - is the time of reaching a plat-
eau level with acceleration value of ma .
The trapezoidal profile formalism looks
as:
+−−−
+
−
=
TttTttda
Tttta
ttttta
att
ta
ppgm
ppm
pssg
ms
),(
,
),(
0;,0
)( , (8)
where gd - is the deceleration gradient,
T - is the plateau’s duration.
Formalisms describing the second type
of the input loads look as:
−
=
mgmj
mj
atatda
ataata
ta
tp
)(0),(
)(),(
0)(,0
)( 1 ,(9)
where j can be altered step-like.
Equations (1)-(9) were involved in this
publication to help readers to understand our
approach to the modeling. Much detailed in-
formation one can find in [18-21]. The final
version of the mathematical model describing
the formal basis of the future software and
simulation results will be published separately.
Requirements to input and output
data organization
As already mentioned above, the “Ac-
cel.exe” is planned to be autonomic software
that provides an option for personalization. To
satisfy these requirements, special algorithms
are needed. They should provide initial data
for characteristics of every vascular compart-
ment, as well as for physiological regulators.
In fact, this is the basic version of physiologi-
cal models (BVPM). All additional proce-
dures for BVPM’s personalizing using the
input data must be algorithmically organized.
1. The input data
BVPM should be tuned for the hemo-
dynamics of a healthy man with mean anthro-
pometric parameters of mas ( M ) and, height
( H ). Special formulas used M to calculate
the total blood volume (V ) must be provided.
Then, utilizing incorporated special massive
of coefficients must be distributed in four
cardiac chambers and 33 vascular (arterial and
venous) compartments. Coefficients will
characterize human horizontal position sec-
tional or regional blood volumes. The next
procedure does provide automatic recalculat-
ing of these initial blood volumes to new ones
characteristic for the relaxed human in a
standard sitting position on a pilot armchair.
Equations for these recalculations must take
into account the initial parameterV . Individu-
al anatomical peculiarities (if they are) con-
cerning lengths of neck, tights, and shins have
to be taken into account.
2. The output data
There are planned two types of output
data: one by default, and another – in special
cases. The default data concerning accelera-
tion profile, arterial pressures in three body
zones (brain, eyes, aortic arch), and HR
should have been presented in graph forms.
This form is recommended to both student-
pilots and instructors. Additional data includ-
ing inside information about parameters of
models is best to collect in table forms. Ex-
perts developing advanced protections can be
the users of these data. Namely, this class of
users can prepare and simulate novel combat
maneuvers avoiding risks for testers.
Conclusion
Combat maneuvers of modern fighter
aircraft originate extreme accelerations nega-
tively influencing on pilot’s physiology and
operability. Empirical investigations were the
only way to develop and test protective meth-
ods and tools providing fighter pilots func-
tionality under combat maneuvers. The main
tools used for acquiring student pilot initial
skills necessary to resist the negative effects
of dynamic extreme accelerations were centri-
Прикладне програмне забезпечення
36
fuges. The skilling process of student pilots of
modern fighter aircraft is not duly formalized
yet. Potentially, special computer simulators
providing additional data concerning charac-
teristics of both human physiology and pro-
tective methods under dynamic accelerations
could improve the skilling process and its
efficiency. Certain scientific-practical prob-
lems associated with creating the needed sim-
ulator have been considered in the paper. To
create special software, quantitative mathe-
matical models must be previously created.
They represent both the human cardiovascular
physiology and protective technologies under
exposure to sustained and extreme zG accel-
erations.
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Received: 05.02.2024
About authors:
Grygoryan Rafik,
Department chief, PhD, D-r in biology
Publications number in Ukraine journals -124
Publications number in English journals -39.
Hirsch index – 11
http://orcid.org/0000-0001-8762-733X
Place of work:
Institute of software systems of
Ukraine National Academy of Sciences
03187, Кyїv,
Acad. Glushkov avenue, 40,
Е-mail:rgrygoryan@gmail.com
.
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