Expanding of Intellectual Possibilities of Digital Tonometers for Home Using
The purpose of the article is to expand the intellectual capabilities of digital blood pressure monitors, which will increase the efficiency of their use at home. The proposed approach boils down to simple computational procedures that can be implemented on the internal processor of a home blood pre...
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irk-123456789-1811182021-11-03T01:26:26Z Expanding of Intellectual Possibilities of Digital Tonometers for Home Using Fainzilberg L.S. Applications The purpose of the article is to expand the intellectual capabilities of digital blood pressure monitors, which will increase the efficiency of their use at home. The proposed approach boils down to simple computational procedures that can be implemented on the internal processor of a home blood pressure monitor. It is shown that to assess long-term variability of indicators, it is enough to use the recurrence formulas for each current measurement to correct the range of recorded values, refine the mean and standard deviation, calculate the Pearson coefficient of variation and the index characterizing the percentage of measurements that exceed established medical standards. Мета статті – розширення інтелектуальних можливостей цифрових тонометрів, які забезпечать підвищення ефективності застосування їх у домашніх умовах. Результати. Встановлено, що в процесі декомпресії манжети на осциляціях спостерігаються характерні фрагменти, викликані зворотною пульсовою хвилею, виявлення яких дає змогу обчислити інтегральний показник жорсткості кровоносних судин за швидкістю розповсюдження пульсової хвилі. Показано, що для оцінки тривалої варіабельності показників достатньо за допомогою рекурентних формул за кожним поточним вимірюванням коригувати діапазон зареєстрованих значень, уточнювати середнє та середнє квадратичне відхилення, обчислювати коефіцієнт варіації Пірсона та індекс, що характеризує відсоток вимірювань, що перевищують встановлені медичні норми. Цель статьи – ррасширение интеллектуальных возможностей цифровых тонометров, которые обеспечат повышение эффективности их применения в домашних условиях. Результаты. Установлено, чтов процессе декомпрессии манжетки на осцилляциях наблюдаются характерные фрагменты, вызванные отраженной пульсовой волной, обнаружение которых позволяет вычислить интегральный показатель жесткости кровеносных сосудов по скорости распространения пульсовой волны. Показано, что для оценки долговременной вариабельности показателей достаточно с помощью рекуррентных формул по каждому текущему измерению корректировать диапазон зарегистрированных значений, уточнять среднее и среднеквадратическое отклонение, вычислять коэффициента вариации Пирсона и индекс, характеризующий процент измерений, превышающих установленные медицинские нормы. 2020 Article Expanding of Intellectual Possibilities of Digital Tonometers for Home Using / L.S. Fainzilberg // Control systems & computers. — 2020. — № 1. — С. 60–70. — Бібліогр.: 32 назв. — англ. 2706-8145 DOI https://doi.org/10.15407/usim.2020.01.060 http://dspace.nbuv.gov.ua/handle/123456789/181118 61.616-71 en Control systems & computers Міжнародний науково-навчальний центр інформаційних технологій і систем НАН та МОН України |
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Applications Applications Fainzilberg L.S. Expanding of Intellectual Possibilities of Digital Tonometers for Home Using Control systems & computers |
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The purpose of the article is to expand the intellectual capabilities of digital blood pressure monitors, which will increase the efficiency of their use at home. The proposed approach boils down to simple computational procedures that can be implemented on the internal processor of a home blood pressure monitor. It is shown that to assess long-term variability of indicators, it is enough to use the recurrence formulas for each current measurement to correct the range of recorded values, refine the mean and standard deviation, calculate the Pearson coefficient of variation and the index characterizing the percentage of measurements that exceed established medical standards. |
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| author |
Fainzilberg L.S. |
| author_facet |
Fainzilberg L.S. |
| author_sort |
Fainzilberg L.S. |
| title |
Expanding of Intellectual Possibilities of Digital Tonometers for Home Using |
| title_short |
Expanding of Intellectual Possibilities of Digital Tonometers for Home Using |
| title_full |
Expanding of Intellectual Possibilities of Digital Tonometers for Home Using |
| title_fullStr |
Expanding of Intellectual Possibilities of Digital Tonometers for Home Using |
| title_full_unstemmed |
Expanding of Intellectual Possibilities of Digital Tonometers for Home Using |
| title_sort |
expanding of intellectual possibilities of digital tonometers for home using |
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Міжнародний науково-навчальний центр інформаційних технологій і систем НАН та МОН України |
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2020 |
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Applications |
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http://dspace.nbuv.gov.ua/handle/123456789/181118 |
| citation_txt |
Expanding of Intellectual Possibilities of Digital Tonometers for Home Using / L.S. Fainzilberg // Control systems & computers. — 2020. — № 1. — С. 60–70. — Бібліогр.: 32 назв. — англ. |
| series |
Control systems & computers |
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AT fainzilbergls expandingofintellectualpossibilitiesofdigitaltonometersforhomeusing |
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2025-07-15T21:43:03Z |
| last_indexed |
2025-07-15T21:43:03Z |
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1837750848509181952 |
| fulltext |
60 ISSN 2706-8145, Системи керування та комп'ютери, 2020, № 1
DOI https://doi.org/10.15407/usim.2020.01.060
UDC 61.616-71
L.S. FAINZILBERG, D.Sc. (Engineering), Professor, Chief Researcher,
International Research and Training Center for Information Technologies and
Systems of the National Academy of Sciences of Ukraine and Ministry of
Education and Science of Ukraine, Acad. Glushkova av., 40, Kiev, 03187, Ukraine,
fainzilberg@gmail.com
EXPANDING OF INTELLECTUAL POSSIBILITIES OF DIGITAL
TONOMETERS FOR HOME USING
The purpose of the article is to expand the intellectual capabilities of digital blood pressure monitors, which will increase the
efficiency of their use at home. The proposed approach boils down to simple computational procedures that can be implemented on
the internal processor of a home blood pressure monitor. It is shown that to assess long-term variability of indicators, it is enough
to use the recurrence formulas for each current measurement to correct the range of recorded values, refine the mean and standard
deviation, calculate the Pearson coefficient of variation and the index characterizing the percentage of measurements that exceed
established medical standards.
Keywords: home blood pressure monitor, vascular elasticity, oscillations, blood pressure variability.
Introduction
Arterial hypertension (high blood pressure) is one
of the most common diseases of the cardio-vascu-
lar system that suffer about 30% of the adult popu-
lation [1]. The prevalence of diseases increases and
reaches 65% among people over 65 years old [2].
With untimely diagnosis and treatment, the disease
can cause serious complications — myocardial
infarction and cerebral stroke, which often result
the patient’s death or disability.
Diagnosis and evaluating the effectiveness of
arterial hypertension treatment primarily involves
the measurement of blood pressure (BP) [3]. The
auscultative method of measuring using the cuff
and tonometer Riva-Rocci has been used in medi-
cal practice for more than a hundred years. With
a decrease in pressure in the cuff, when the blood
begins to pass through the squeezed section of
the vessel, vortices and turbulence appear, crea-
ting characteristic sounds (Korotkov tones) that
are heard in the phonendoscope and determine
the levels of systolic and diastolic blood pressure.
Due to its accuracy, simplicity and accessibility, the
Korotkov method has become the gold standard
and is recommended by the World Health Organi-
zation for worldwide use.
Along with the advantages, the auscultative
method has a number of disadvantages that limit
its use at home [4]. Firstly, listening to Korotkov’s
tones requires certain qualifications, especially
when measuring the patients’ blood pressure with
the so-called effects of "acoustic failure" or "infinite
tone, which, according to statistics, are found in
7% of patients. Secondly, even with typical Korot-
kov tones, the measurement accuracy substantially
depends on the location of the phonendoscope on
the arteries, and the error increases significantly
when measured through clothing. And finally, the
main drawback of the Korotkov method is the
complexity of the measurement automation, which
makes it difficult to build reliable digital blood pres-
sure monitors for home use.
Control at home provides the possibility of long-
term monitoring, which is extremely important
both for the prevention of arterial hypertension
Expanding of Intellectual Possibilities of Digital Tonometers for Home Using
ISSN 2706-8145, Control systems and computers, 2020, № 1 61
and for further monitoring after discharge of pa-
tients from the hospital. Therefore, home observa-
tion, without pretending to replace the traditional
clinical measurement, is an informative method for
clarifying the diagnosis in most clinical situations,
especially in people with suspected "masked hyper-
tension".
Recently, the market of medical devices for
home use has been developing rapidly [5—7]. A
significant place in this market is occupied by home
blood pressure monitors, which allow individuals
without special medical training to independently
control blood pressure [8—10].
In such tonometers, the oscillometric method
of measurement is most often used, it is based on
recording the amplitude of the pulsations of air
pressure at the time of passage of blood through
the portion of the artery squeezed by the cuff. The
method allows you to automatically measure with
weak tones of Korotkov, in the presence of the
phenomenon of “auscultation failure” and other
effects that are difficult for the process of automa-
tion of measurement by the Korotkov method.
In addition, the oscillometric method can be
used at a high noise level, its results are almost inde-
pendent of the turn and movement of the cuff along
the arm, and the measurement accuracy does not
decrease when determined through the thin fabric
of clothes.
Digital tonometers based on the oscillometric
method are constantly being improved. Recently,
a new generation of devices for home use has ap-
peared, in which intelligent technologies are im-
plemented that provide protection against errors in
various arrhythmias, including arterial fibrillation,
weak pulses and other difficult situations. Tonome-
ters of this class are represented on the medi-
cal equipment market by well-known companies
Omron and Citizen (Japan), Mocrolife (Sweden),
Medisana (Germany), Gamma (England) and seve-
ral other companies.
Analysis of available publications shows that
the intellectual capabilities of home blood pres-
sure monitors are far from exhausted. The rapid
development of microelectronics and intelligent
methods for detecting subtle changes in signals of
a complex shape against a background of interfe-
rence make it possible today to realize a number of
important additional functions in tonometers.
The purpose of this article is to further expand
the intellectual capabilities of digital blood pres-
sure monitors, which will increase the efficiency of
their using at home.
Integral assessment of blood vessel
elasticity
Human vascular system consists of veins, arteries
and capillaries. The total length of the blood ves-
sels of the human body is about 100 thousand kilo-
meters, which is more than twice the length of the
equator of the Earth.
Determination of the blood vessels properties
is an important link for the early detection, pre-
vention and treatment of cardiovascular diseases.
Elastic vessels allow you to save the stroke volume
of blood, reduce the load on the heart and ensure
smooth movement of blood from vessels of large
diameter to vessels of smaller diameter. As a result,
the pulsating blood flow from the heart is converted
into a continuous and even flow through the entire
vascular bed, which is very important for the nor-
mal functioning of the body.
It is known that aging of the body is accompa-
nied by a loss of elasticity of blood vessels [11]. An
increase in arterial stiffness leads to an increase in
the pulse wave propagation speed, and this factor is
currently recognized as one of the main risk factors
for hypertension and the occurrence of coronary
heart disease [12–14].
In recent years, non-invasive rheography
methods have become widespread [15], which pro-
vide automatic determination of the pulse wave
propa-gation velocity and the other parameters of
vascular stiffness, which carry information about
the initial signs of cardiovascular pathologies. In
clinical conditions, the pulse wave velocity (PWV)
is determined using special sensors installed in the
carotid and femoral arteries. In this case, the PWV
is estimated by the value of the delay of the signal
recorded by these sensors [16].
There is another way: PWV is estimated by the
time between the moments of the appearance of a
direct pulse wave 1 generated by the current heart
Fainzilberg L.S.
62 ISSN 2706-8145, Системи керування та комп'ютери, 2020, № 1
beat and a reverse pulse wave 2 reflected from the
extremities (Fig. 1).
At the current contraction of the heart (systole),
a wave of increased pressure occurs (direct pulse
wave 1), which propagates through all blood ves-
sels. Reaching the limbs, this wave is reflected and
generates an “echo” wave” 2, which propagates in
the opposite direction of the vascular tree. With
elastic arteries, the pulse wave propagation speed
is relatively low and reflected wave 2 returns to the
ascending aorta during the diastole (relaxation of
the heart muscle). Such a delay is favorable, since
in this case the reflected wave does not overlap the
systolic phase and does not affect the systolic blood
pressure.
On the contrary, with a decrease in vascu-
lar elasticity, the pulse wave propagation velocity
increases. As a result, reflected wave 2 returns
to the heart already in the systole period, which
leads to an increase in systolic blood pressure, an
increase in afterload on the heart, an increase in
oxygen consumption by the myocardium and
damage to arteries [17]. Therefore, an assessment
of the elasticity of blood vessels can provide impor-
tant information about the complex of risk factors
for cardiovascular diseases [18].
Let us show that digital tonometers with a cer-
tain improvement tare able to provide information
about the pulse wave propagation speed and there-
by evaluate the integral stiffness index of blood ves-
sels. To do this, we first consider some details of the
oscillometric measurement method (Fig. 2).
Fig. 2. illustrates the methodology of the oscil-
lometric measurement method:
a) a graph of changes in air pressure in the cuff;
b) signal after trend removal;
c) micropulsation (oscillation) of the signal
during the measurement;
d) the calculation of the systole and diastole
blood pressure levels by the "bell".
The initial data for the calculation is a finite
sequence of discrete pressure values
KPPP ...,,, 21 , (1)
which record during decompression from the ini-
tial value above the expected systolic to the final
value below the estimated diastolic pressure (Fig.
2, a). Recursive procedure:
Fig. 1. Pressure in the bloodstream generated by forward 1
and backward 2 pulse waves
Fig. 2. The methodology of the oscillometric measurement
method
Expanding of Intellectual Possibilities of Digital Tonometers for Home Using
ISSN 2706-8145, Control systems and computers, 2020, № 1 63
1 10 0
0
1 ( )
1 2k k k W k WP P P P
W− + − −= + −
+
� � ,
0 0W k K W≤ ≤ −
(2)
with a sufficiently large window 0W allows us to es-
timate the low-frequency trend of values and sub-
tract it from the initial data (Fig. 2, b).
Further processing ensures the construction
of the amplitudes array îY , 1,...,i N= of the signal
micropulsations, the level of which exceeds a pre-
determined threshold of insensitivity. Using special
procedures, a “bell” is constructed – an approxi-
mation dependence of the amplitudes
îY , 1,...,i N=
of micropulsations relative to the corresponding
pressure levels during the decompression period.
The systolic and diastolic pressure levels iP are esti-
mated by the maximum maxP of this bell (Fig. 2, c)
using the formulas
1 maxSPB q P= , (3)
2 maxDBP q P= , (4)
where 1q , 2q are empirical coefficients.
Experimental studies have shown that the intel-
ligent computational procedures, proposed in [19],
make it possible by the signal ( )P t recorded during
the decompression process to obtain not only the
information necessary for measurement blood pres-
sure levels, but also to “see” the fragments carrying
information about pulse wave velocity. This gives
us the key to the construction of a new generation
of home blood pressure monitors, which allow the
integral measurement of the stiffness of blood ves-
sels during the measurement process [20].
Figure 3 shows a graph of the signal ( )P t during
the cuff decompression. At pressures close to SBP
and DBP fragments F caused by the reflected pulse
wave are observed on the oscillations. Such frag-
ments have the characteristic shape and can be
automatically detected using computer algorithms
implemented on the internal processor of a home
digital blood pressure monitor.
To determine the elasticity of the vessels, we cal-
culate the time delays , 1,2,...l lτ = between the mo-
ment when the corresponding oscillation takes the
maximum value and the moment of appearance of
the fragment F caused by the reflected wave. Then,
we determine the average value of time delays for a
certain sequence L of such oscillations:
1
1 L
l
lL
τ τ
=
= ∑
.
(5)
The obtained value makes it possible to deter-
mine the average propagation time of the pulse
wave in the forward and reverse directions of blood
flow, by which it is possible to integrally evaluate
the elasticity of the patient’s blood vessels (stiffness
index) by formula
2HI
τΩ = ,
(6)
where H — patient height.
Checking the effectiveness of the proposed ap-
proach was carried out using a computer prog-
ramme, the input of which received a sequence of
(1) pressures during the oscillometric measure-
ment using BP by home tonometer. The stiffness
index IΩ was calculated according to the method
described above, for which the programme imple-
ments computational procedures for searching and
automatically recognizing fragments F of oscilla-
tions generated by reflected waves.
Fig. 3. Illustration of the proposed method
Fainzilberg L.S.
64 ISSN 2706-8145, Системи керування та комп'ютери, 2020, № 1
Experimental studies were conducted with a
group of healthy volunteers (27 people of both
sexes) of different age groups. Figure 4 shows the
results of calculation experiments obtained from
three healthy volunteers.
The first person was 57 years old, H=1,76 m.
The time delays between the maximum values
of the oscillations and the moments of the ap-
pearance of fragments generated by the reflected
pulse wave in two successive oscillations were
1 2 0,184 sτ τ= = (Fig. 4, a). Therefore 0,184 sτ =
and (2 1,76) / 0,184 19,1 m/sIΩ = ⋅ = .
The second volunteer was 35 years old, H=
=1,78 m. The time delays between the maximum
values of the oscillations and the moments of the
appearance of fragments generated by the reflec-
ted pulse wave in two successive oscillations were
1 0,288 sτ = , 2 0,232 sτ = (Fig. 4, b). Therefore
0,26 sτ = and (2 1,78) / 0,26 13,7IΩ = ⋅ = .
The third person was 14 years old, H=1,65 m.
The time delays between the maximum values of
the oscillations and the moments of the appearance
of fragments generated by the reflected pulse wave
in two successive oscillations were 1 0,256 sτ = ,
2 0,288 sτ = (Fig. 4, c).
Therefore 0,272 sτ = and (2 1,65) / 0,272I = ⋅ =
12,1 m/s= .
The results are consistent with the well-estab-
lished notion of clinicians about increasing the
value of the stiffness index as the body ages.
An analysis of the publications suggests that the
pulse wave form carries information not only about
vascular stiffness, but also about other important
characteristics of the body [21]. Therefore, it is
advisable to direct further research to the construc-
tion of diagnostic models that allow one to indi-
rectly evaluate these characteristics in the process
of oscillometric measurement BP and implement
these models into home blood pressure monitor.
Let us consider one of the possible approaches to
solving this problem.
By analogy with [22], let us approximate the re-
sulting signal generated by the direct and reflected
pulse waves (see Fig. 1) as the sum of the asymmet-
ric Gaussian functions
2 2
1 2
1 22 2
1 2
( ) ( )ˆ( ) exp exp
2[ ( )] 2[ ( )]
t tP t A A
b t b t
μ μ⎛ ⎞ ⎛ ⎞− −
= − + −⎜ ⎟ ⎜ ⎟
⎝ ⎠ ⎝ ⎠
,
1,2,....t = , (7)
in which
2μ = 1μ τ + , (8)
and
(1)
(2)
, при ,
( )
, при ,
i i
i
i i
b t
b t
b t
μ
μ
⎧ ≤⎪= ⎨
>⎪⎩
i=1,2. (9)
Next, we calculate the optimal values of eight
parameters iA , iμ , (1)
ib , (1)
2b , 1,2i = which are figu-
ring in (7), which satisfying the criterion of the
minimum mean square deviation of discrete values
ˆ( )P t from the observed values ( )P t . To determine
the optimal values iA, iμ ,
(1)
ib ,
(1)
2b , 1,2i = you may use
the analytical method described in [22]. However,
from a computational point of view, this method
seems rather cumbersome for its implementation
on the internal processor of a home blood pressure
monitor.
But we may go the other way. The experiments
showed that acceptable values iA, iμ ,
(1)
ib ,
(1)
2b , 1,2i =
can be found by a simple search procedure using
a set of pretabulated exponential functions
xy e=
with different values of the argument x. As a result,
the real signal generated by the direct and reflected
waves uniquely encodes by totality of the parame-
ters found (Fig. 5).
Fig. 4. Results of experiments on the calculation for dif-
ferent ages volunteers: 57 years old (a); 35 years old (b);
14 years old (c)
m/s
Expanding of Intellectual Possibilities of Digital Tonometers for Home Using
ISSN 2706-8145, Control systems and computers, 2020, № 1 65
Fig. 5. The result of approximation of the real pulse wave
by function (7)
As can be seen from fig. 5, the found optimal
values of the parameters iA, iμ ,
(1)
ib ,
(1)
2b , 1,2i = charac-
terize the shape of the observed pulse wave quite
well, which means that they can be used as argu-
ments of models
(1) (2)( , , , )j j i i i iZ Z A b bμ= , 1,...j J= , (10)
providing the indirect determination of physiologi-
cal characteristics jZ 1,...j J= . Identification of
such models is supposed by observation samples
based on the inductive modeling methods [23].
Assessment of blood pressure
variability with a home blood
pressure monitor
It is known that most physiological parameters
(pulse rate, blood pressure and many others) are
subject to significant spontaneous fluctuations (true
biological variability) [24, 25]. If such fluctuations
lie within certain limits, then this is considered a
physiological norm. According to [26], in practi-
cally healthy people aged 20 to 60 years, the daily
variability in blood pressure is at least 10% of the
average levels SBP and DBP.
24 hour monitoring of blood pressure, which
is carried out using the special devices, allows to
determine the time intervals T
1
, T
2
, …, when BP
exceeds the norm (Fig. 6), to evaluate the average
values in the daytime and nighttime and a number
of other indicators that carry valuable information
in the diagnosis of hypertension [ 27].
Of course, 24 hour monitoring has a number
of advantages compared to measuring blood pres-
sure in a medical institution. The method allows to
obtain a profile (series of values) BP under condi-
tions typical for the patient and thereby eliminate
the so-called “white medical gown” effect. In ad-
dition, it becomes possible to identify patients with
a high risk of cardiovascular complications due to
the lack of an adequate reduction BP at night and
night time hypertension.
However, it is clear that 24 hour monitoring does
not allow to assess the long-term variability BP
between visits to the doctor (so called visit-to-visit
variability), which, according to the doctors, is very
important for making the right diagnostic decisions
[28—31].
Let us show that minor improvements to the
home blood pressure monitor will provide the user
with a number of additional useful functions that
characterize the individual characteristics of ones
pressure profile.
We will consider the values SBP
i
, i=1,2,... of
systolic blood pressure, which were observed in a
particular user over a sufficiently large period of
time (weeks, months, years), as the implementation
of a random variable P with a probability distribu-
tion SBPℜ .
We denote the carrier of this distribution by the
set
{ : 0}SBP SBPPΩ = ℜ > , (11)
and let M
SBP
be the average value of SBP
i
, i=1,2,... .
Let further
(0) [100, 120]SBPΩ = be the set (range) of
normal values accepted in medical practice SBP1.
We consider four options for the mutual arrange-
ment of sets and relative to the axis of values (Fig. 7).
Case 1. (0)
SBP SBPΩ ⊂ Ω , i.e. the range SBPΩ of mea-
sured values is fully included in the normal range
(0)
SBPΩ of systolic blood pressure.
Fig. 6. Profile for 24 hour monitoring of blood pressure
Fainzilberg L.S.
66 ISSN 2706-8145, Системи керування та комп'ютери, 2020, № 1
Case 2. (0)( )SBP SBPΩ ∩ Ω ≠ ∅,
( )/ ( )щ
SBP SBP SBPΩ Ω ∩ Ω ≠
≠ ∅, the range SBPΩ partially enters the region
(0)
SBPΩ ,
moreover
(0)
SBP SBPM ∈Ω , i.e. the average of the mea-
sured values belongs to the normal range (0)
SBPΩ of
systolic blood pressure.
Case 3. (0)( )SBP SBPΩ ∩ Ω ≠ ∅,
( )/ ( )щ
SBP SBP SBPΩ Ω ∩ Ω ≠
≠ ∅, i.e. the range SBPΩ partially enters to the re-
gion
(0)
SBPΩ , moreover (0)
SBP SBPM ∉Ω , i.e. the average
of the measured values do not belong to the normal
range (0)
SBPΩ of systolic blood pressure.
Case 4.
(0)( )SBP SBPΩ ∩ Ω = ∅ , those the range of
measured values SBPΩ extends beyond the normal
range
(0)
SBPΩ of systolic blood pressure.
In the first case, the patient should be considered
healthy. In the second case, the results of indivi-
dual measurements did not correspond to the nor-
mal range
(0)
SBPΩ . But since the average SBPM of the
measured values belongs to the region
(0)
SBPΩ , such
a patient can be classified as conditionally healthy
with a tendency to hypertension. In the third case,
and especially in the fourth, there is nothing left to
do but to attribute the patient to a group of patients
with varying degrees of arterial hypertension.
Note that for the practical implementation of
the proposed approach, it is not necessary to have
the entire array of measured values. For each mea-
surement SPB
i
it is enough to override the mini-
mum SBP
min
and maximum SBP
max
of full array
by scheme
min, min, 1, ifi i i iSBP SPP SPP SBP −= < , (12)
max, max, 1, ifi i i iSBP SPP SPP SBP −= > , (13)
and refine the current average SBPM using a recur-
rence formula
, , 1 , 1
1[ ]SBP i SBP i i SBP iM M SBP M
i− −= + −
, (14)
by setting the initial conditions ,0 0SBPM = and also
min,0 max,0 0SBP SBP SBP= = .
Applying the recurrence formula for calculating
the modified random variance estimate for a sample
of independent observations proposed in [32], it is
also possible for each measurement iSBP, i=1,2,...
to reevaluate the current value of the mean square
(standard) deviation SBPσ of the systolic blood pres-
sure value for a particular patient.
To prevent distortion minSBP , maxSBP , SBPM and
SBPσ is advisable to provide an additional button
in the tonometer, with which the user can block the
recalculation of these values at the slightest suspi-
cion of an error in the current result due to random
artifacts.
With each measurement we can also calcu-
late the current values of Pearson coefficient of
variation
100%SBM
SBP
SBM
V
M
σ
= ⋅
(15)
and index
,
(16)
Condition Text mes-
sage
Emoticon
+ KPPP ...,,, 21
Dange-
rous
condition!
+ 0,5 SBP SBPσ ≤ Δ ≤ Be
careful!
+
or
-
0,5SBP SBPσΔ < Stable
condition!
- 0,5 SBP SBPσ ≤ Δ ≤ The
condition
is impro-
ving
- 1,5SBP SBPσΔ > You are
in good
condition
Table 1. One of the option for generating quality
information (when SBP > 100 mmHG)
1,5 SBPσ≤
1,5 SBPσ≤
( )
100%
E
SBP
SBP
NI
N
= ⋅
Fig. 7. The relative position of the sets and ( SBPΩ (0)
SBPΩ
Expanding of Intellectual Possibilities of Digital Tonometers for Home Using
ISSN 2706-8145, Control systems and computers, 2020, № 1 67
characterizing the ratio of the number of measure-
ments at which the systolic blood pressure excee-
ded the threshold SBH = 140 mmHg to the total
number of measurements.
In addition, with each measurement, we may
calculate the value
,SBP i i SBPSBP MΔ = − , 1,2,...i = (17)
characterizing the deviation of the current result
SBP
i
from the previously found average value M
SBP
,
and compare the value ,SBP iΔ with the current value
of the standard deviation SBPσ .
As a result, with a simple refinement of the inter-
nal software, the home blood pressure monitor can
additionally display on its screen quality informa-
tion about the current functional state of the pa-
tient in the form of understandable graphic images
(emoticons). One of the options for the formation
of such information is presented in table 1.
In a similar way, we can calculate the values
minDBP , maxDBP , DBPM , DBPσ , DBMV , DBMI allowing us to
estimate the variability of diastolic blood pressure
iDBP, 1,2,...i = .
To illustrate, consider an example of the forma-
tion of qualitative information in the analysis of
systolic blood pressure.
Figure 8 shows a graph of the results of 85 mea-
surements recorded over a period of three months
using home tonometer by a patient who did not
undergo antihypertensive therapy. Statistical cha-
racteristics of the results are summarized in table 2.
Since the average value of the results is out-
side the range of the currently accepted norm
( 120 mmHgSBPM > ) this patient should be recog-
nized as ill person (see Case 3 on Figure 7).
Figure 9 shows the areas of a qualitative assess-
ment of the results, constructed according to the
data of tables 1 and 2.
A qualitative assessment of the results of blood
pressure measurements, implemented in a home
blood pressure monitor, helps a user who does not
have a medical education make independent deci-
sions aimed at optimizing his lifestyle, a reaso-
nable distribution of the regime of load and rest,
determine the need for additional intake of medi-
cations prescribed by a doctor, and evaluate pos-
sible dangerous situations requiring urgent medical
attention.
Of course, the proposed approach in no way
claims to replace, and even more so to cancel the
established medical recommendations for the diag-
nosis and treatment of hypertension.
Conclusion
The article shows that the modern intelligent in-
formation technologies can implement a number
of important additional functions for improving
the efficiency of digital blood pressure monitors for
home use.
It has been shown that directly in the process of
the oscillometric method for determining blood
pressure, home tonometers can provide the user an
integrated assessment of the arterial stiffness index,
which provides important diagnostic information
about the complex of risk factors for cardiovascular
diseases.
An approach has been proposed that allows us
to assess the long-term variability of blood pressure
indicators for self-measurement at home between
visits to the doctor, which increases the reliability
of decisions by eliminating the so-called “white
medical gown” effect.
Fig. 8. Results of registration of systolic blood pressure by
home tonometer
SBPmax SBPmin MSBP σ
SBP
V
SBP
(%)
187 113 142,7 12,4 8,7
Table 2. Statistical characteristics of the measurement re-
sults SBP, mmHG
Fig 9. The example of qualitative assessment of the
measurement results
P, mmHg
Fainzilberg L.S.
68 ISSN 2706-8145, Системи керування та комп'ютери, 2020, № 1
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Received 01.01.2020
Л.С. Файнзільберг, доктор техн. наук, професор, головний науковий співробітник,
Міжнародний науково-навчальний центр інформаційних технологій та систем НАН та МОН України,
просп. Глушкова, 40, Київ 03187, Україна,
fainzilberg@gmail.com
РОЗШИРЕННЯ ІНТЕЛЕКТУАЛЬНИХ МОЖЛИВОСТЕЙ
ЦИФРОВИХ ТОНОМЕТРІВ ДЛЯ ДОМАШНЬОГО ВИКОРИСТАННЯ
Вступ. Артеріальна гіпертензія (підвищений артеріального тиск) — одне з найпоширеніших захворювань серцево-
судинної системи. Діагностика та оцінка ефективності лікування артеріальної гіпертензії передбачає вимірювання
артеріального тиску, в тому числі за допомогою цифрових домашніх тонометрів. Однак інтелектуальні можливості
таких тонометрів далеко не вичерпано.
Fainzilberg L.S.
70 ISSN 2706-8145, Системи керування та комп'ютери, 2020, № 1
Мета статті – розширення інтелектуальних можливостей цифрових тонометрів, які забезпечать підвищення
ефективності застосування їх у домашніх умовах.
Методи. Для досягнення поставленої мети сформульовано та досліджено два завдання. Перше завдання
спрямовано на визначення можливості цифрового тонометра оцінити інтегральний показник (індекс) жорсткості
кровоносних судин на основі визначення швидкості поширення пульсової хвилі за сигналом, що реєструється в
процесі осцилометричного способу вимірювання артеріального тиску. Друге завдання орієнтовано на розробку
простих засобів, що забезпечують оцінку тривалої варіабельності показників артеріального тиску при самостійному
вимірюванні в домашніх умовах між відвідинами лікаря (visit-to-visitvariability).
Результати. Встановлено, що в процесі декомпресії манжети на осциляціях спостерігаються характерні
фрагменти, викликані зворотною пульсовою хвилею, виявлення яких дає змогу обчислити інтегральний показник
жорсткості кровоносних судин за швидкістю розповсюдження пульсової хвилі. Показано, що для оцінки тривалої
варіабельності показників достатньо за допомогою рекурентних формул за кожним поточним вимірюванням
коригувати діапазон зареєстрованих значень, уточнювати середнє та середнє квадратичне відхилення,
обчислювати коефіцієнт варіації Пірсона та індекс, що характеризує відсоток вимірювань, що перевищують
встановлені медичні норми.
Висновки. Запропонований підхід зводиться до простих обчислювальних процедур, які можуть бути реалізовані
на внутрішньому процесорі домашнього тонометра.
Ключові слова: домашній тонометр, еластичність судин, осциляції, варіабельність артеріального тиску.
Л.С. Файнзильберг, д-р техн. наук, профессор, глав. науч. сотруд., Международный
научно-учебный центр информационных технологий и систем НАН и МОН Украины,
просп. Глушкова, 40, Киев 03187, Украина,
fainzilberg@gmail.com
РАСШИРЕНИЕ ИНТЕЛЛЕКТУАЛЬНЫХ ВОЗМОЖНОСТЕЙ
ЦИФРОВЫХ ТОНОМЕТРОВ ДЛЯ ДОМАШНЕГО ПРИМЕНЕНИЯ
Введение. Артериальная гипертензия (повышенное артериального давление) — одно из наиболее распрос-
транённых заболеваний сердечно-сосудистой системы. Диагностика и оценка эффективности лечения
артериальной гипертензии предполагает измерение артериального давления, в том числе с помощью цифровых
домашних тонометров. Однако интеллектуальные возможности таких тонометров далеко не исчерпаны.
Цель статьи – ррасширение интеллектуальных возможностей цифровых тонометров, которые обеспечат
повышение эффективности их применения в домашних условиях.
Методы. Для достижения поставленной цели сформулированы и исследованы две задачи. Первая задача
направлена на определения возможности цифрового тонометра оценить интегральный показатель (индекс)
жесткости кровеносных сосудов на основе определения скорости распространения пульсовой волны по сигналу,
регистрируемому в процессе осциллометрического способа измерения артериального давления. Вторая задача
ориентирована на разработку простых средств, обеспечивающих оценку долговременной вариабельности
показателей артериального давления при самостоятельном измерении в домашних условиях между посещениями
врача (visit-to-visit variability).
Результаты. Установлено, чтов процессе декомпрессии манжетки на осцилляциях наблюдаются характерные
фрагменты, вызванные отраженной пульсовой волной, обнаружение которых позволяет вычислить интегральный
показатель жесткости кровеносных сосудов по скорости распространения пульсовой волны. Показано, что
для оценки долговременной вариабельности показателей достаточно с помощью рекуррентных формул по
каждому текущему измерению корректировать диапазон зарегистрированных значений, уточнять среднее и
среднеквадратическое отклонение, вычислять коэффициента вариации Пирсона и индекс, характеризующий
процент измерений, превышающих установленные медицинские нормы.
Выводы. Предложенный подход сводится к простым вычислительным процедурам, которые могут быть
реализованы на внутреннем процессоре домашнего тонометра.
Ключевые слова: домашний тонометр, эластичность сосудов, осцилляции, вариабельность артериального давления.
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