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<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta>
      <journal-title-group>
        <journal-title>R. Beyar, Challenges in Organ Transplantation. Rambam Maimonides Medical Journal</journal-title>
      </journal-title-group>
    </journal-meta>
    <article-meta>
      <article-id pub-id-type="doi">10.1109/EWDTS52692.2021.9581002</article-id>
      <title-group>
        <article-title>Prevention Based on Donor and Recipient Health Monitoring</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Tetiana Hovorushchenko</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Peter Popov</string-name>
          <email>p.t.popov@city.ac.uk</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Mariia Kapustian</string-name>
          <email>kapustian.mariia@gmail.com</email>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Denys Lyubovetskyi</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Information</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>System</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>City University of London</institution>
          ,
          <addr-line>Northampton Square, London, EC1V 0HB</addr-line>
          ,
          <country country="UK">United Kingdom</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Cyber-physical system</institution>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>Khmelnytskyi Lyceum No.</institution>
          <addr-line>17, Proskurivskoho Pidpillya str., 89, Khmelnytskyi, 29000</addr-line>
          ,
          <country country="UA">Ukraine</country>
        </aff>
        <aff id="aff3">
          <label>3</label>
          <institution>Khmelnytskyi National University</institution>
          ,
          <addr-line>Institutska str., 11, Khmelnytskyi, 29016</addr-line>
          ,
          <country country="UA">Ukraine</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2016</year>
      </pub-date>
      <volume>2</volume>
      <issue>2</issue>
      <fpage>0000</fpage>
      <lpage>0002</lpage>
      <abstract>
        <p>Today in Ukraine the problem of transplantation of organs and other anatomical materials to humans is very acute. Among the reasons hindering the development of transplantation of anatomical materials to humans in Ukraine is the rejection of donor organs by the recipient's body. The dependences of the process of rejection of donor organs by the recipient's body on the different surface structures of cells in the recipient and donor, on the incompatibility of recipient and donor on HLA antigens, on the level of dangerous antibodies in the recipient's body, on consideration of only the waiting time for the distribution of donor organs, on the origin of the donor organ (cadaveric organ or organ from a living donor), on the general health of the recipient, on the age of the donor, on the gender of the recipient, on the recipient's disease and its phase, which required transplantation, on the chosen type of immunosuppressive therapy, and on the presence of progressive chronic dysfunction of the transplanted organ. The established dependencies are useful in the selection of donor organs in order to minimize the risk of rejection of organs by the recipient. Rules and method for supporting the decision on the possibility or undesirableness of donation and transplantation, taking into account the risks of rejection of donor organs, have been developed. The architecture of the cyber-physical system for donor organs' rejection risks prevention based on donor and recipient health monitoring is developed, aimed at verifying the existing list of factors of donor organ rejection. Based on this test, the developed cyber-physical system offers a conclusion on the possibility (if all donor organ rejection factors are eliminated or minimized) or undesirableness (if one or a group of donor organ rejection factors cannot be eliminated) of donation and transplantation in a given case.</p>
      </abstract>
      <kwd-group>
        <kwd>Monitoring</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>-</title>
      <p>Organ and</p>
      <p>Tissue</p>
      <p>Transplantation, donor, recipient, rejection of donor organs.</p>
    </sec>
    <sec id="sec-2">
      <title>1. Introduction</title>
      <p>Today in Ukraine the problem of transplantation of organs and other anatomical materials to
humans is very acute. Every year, thousands of Ukrainians need organ transplants to save their lives,
but there are only a few transplant surgeries. In total, today there are more than 1 million people with
transplanted organs who lead an active lifestyle and even play sports [1, 2]. In developed countries,
organ transplantation is the standard of care for many diseases of the kidneys, heart, liver, lungs, and
others. Ukraine lags behind by 20-25 years in the development of organ transplantation due to lack of</p>
      <p>2022 Copyright for this paper by its authors.
funding for transplantation, lack of a single register of donors, the ratio of presumption of consent and
disagreement, prospects for the development of transplant coordination services, problems of
education and training of doctors, lack of a single electronic register, etc.[3].</p>
      <p>According to the Law of Ukraine "On the use of transplantation of anatomical materials to
humans" [4], transplantation activities should be based solely on the Unified State Information
System on Organ and Tissue Transplantation (USIST). In general, the productivity of health workers
increases with the use of decision support systems and information technology, as they provide
doctors with relevant information, increase the efficiency of modern medical resources, promote the
integration of Ukrainian medicine into the global medical space [5-7].</p>
      <p>Among the reasons hindering the development of transplantation of anatomical materials to
humans in Ukraine is the rejection of donor organs by the recipient's body, despite careful verification
of the compatibility of organs or other anatomical materials of the donor and recipient. Serious
adverse events and the continuing risk of chronic transplant rejection continue to be a problem for
transplantation [8].</p>
      <p>Thus, a successfully developed and implemented the cyber-physical system for donor organs'
rejection risks prevention based on donor and recipient health monitoring may be relevant and
important for USIST, because it will help decide on the possibility or undesirableness of donation and
transplantation in a given case, taking into account factors of the donor organs' rejection.</p>
    </sec>
    <sec id="sec-3">
      <title>2. Literature Review</title>
      <sec id="sec-3-1">
        <title>Let's review the known cyber-physical systems for health status monitoring.</title>
        <p>The lifestyle changes of people have been resulting in increase in their health problems. This
demands a need for cyber-physical systems involving ubiquitous healthcare system. Cyber-physical
systems have a large potential in healthcare for improving the treatment quality and increasing the
patients' assistance speed. Cyber-physical systems help automatizing the treatment process and using
multiple medical devices simultaneously. These systems allow gathering information about patient's
health that provide reducing the progressions of a disease and improving the patient's healing process.
Cyber physical systems have behaviour, which emergent from the interactions of physical systems
with software systems. The medical cyber-physical system is a unique cyber-physical system, which
combines networking capabilities, embedded software control devices and complex physiological
dynamics of patients in the modern medical field. Medical cyber-physical systems are the
interconnected, dependable and intelligent system of embedded medical devices used to monitor and
control multiple aspects of the patients’ physiological state [9-18].</p>
        <p>Paper [9] develops module for data analysis of the architecture of centralized healthcare
cyberphysical system, which identifying the causes of diseases, researching the new diseases, automatizing
the health monitoring of patients and remote treatment, providing the actual information about disease
and treatment methods for clinics of the centralized healthcare cyber-physical system.</p>
        <p>Paper [10] develops a framework for health's calculating and monitoring in cyber-physical systems
using data driven techniques. The framework consists of four components: data acquisition and
feature extraction, state identification and real time state estimation, cyber-physical health calculation,
operator warning generation.</p>
        <p>In the paper [11] the independent health monitoring mechanism as a human-recognizable measure
of system's trustworthiness is proposed. This mechanism detects actual violations of constraints and
calculates the possibility to violate the constraints. The proposed health monitor consists of two
components: health measurement functions, which are tailored to each component of the
cyberphysical system; the probabilistic health-state determination, which is directly derived from Bayesian
estimation methods.</p>
        <p>Security of the data in the cyber-physical systems is key concern when it is accessed from remote
location. Because medical practitioners use this data for making the health related decisions, risk of
intrusion is present. The main objective of the paper [12] is presenting the state-of-the-art review on
security challenges, security requirements and current authentication schemes of cyber-physical
systems for health monitoring.</p>
        <p>The overview [13] presents architectures and frameworks of the medical cyber-physical system
from different perspectives, modeling and verification methods, identification and sign sensing
technologies, key communications' technologies, data storage and analysis technologies, monitoring
systems, data security and privacy protection technologies, and key research perspectives and
directions.</p>
        <p>The paper [14] studies the perspective of interoperability of health data (different type of data
based on different types of sensors and other medical devices) on cloud-based medical cyber-physical
systems, and proposes a conceptual framework to support healthcare professional with an integrated
view of the heterogeneous data for analysing, sharing, and decision making.</p>
        <p>The authors of [15] review the state-of-the-art in enabling quality of service (QoS) for remote
health care applications using technological advancements in the area of Internet of things. In
particular, they investigate the QoS challenges required to meet the analysis and inferencing needs of
such applications and to overcome the limitations of existing big data processing tools.</p>
        <p>The development of medical devices connected to Internet of things has been alleviating the strain
on the modern healthcare system by giving users the opportunity to reside in the home during
treatment or rehabilitation. The paper [16] studies recent state-of-the-art research on the field of
Internet of things for health monitoring, examines several potential use cases of blending the
technology.</p>
        <p>Authors of [17] propose a reliability/availability quantification methodology for the
Internet-ofMedical Things infrastructure using a hierarchical model of three levels: fault tree of overall
infrastructure consisting of CFE member systems; fault tree of subsystems; continuous-time Markov
chain models of components/devices in the subsystems. Five case-studies of configuration alternation
and four operational scenarios of the Internet-of-Medical Things infrastructure are considered in [17]
to comprehend the dependability characteristics of the Internet-of-Medical Things physical
infrastructure.</p>
        <p>The paper [18] focuses on discussing core technologies that are shaping Internet of Things-based
healthcare. Further, the paper provides challenges that must be addressed so that the Internet of
Things-based healthcare system becomes robust.</p>
        <p>A review of known cyber-physical systems for health status monitoring showed that, despite a
large number of different solutions, a cyber-physical system for donor organs' rejection risks
prevention based on donor and recipient health monitoring is currently lacking, and existing
cyberphysical systems cannot be used as a subsystem (module) of USIST for deciding on the possibility or
undesirableness of donation and transplantation in a given case, taking into account the factors of
rejection of donor organs. Therefore, the aim of this study is to develop a cyber-physical system for
donor organs' rejection risks prevention based on donor and recipient health monitoring, and the
method on which it will be based.</p>
        <p>Such a system, like any decision support system, should be represented as a tuple of several sets
in particular, a set of basic elements (based on subject area analysis), a set of rules, and a set of
methods used to process information. Therefore, in order to develop a cyber-physical system for
donor organs' rejection risks prevention based on donor and recipient health monitoring, the following
tasks should be solved:
1. conducting the analysis of the subject area for determining the factors of rejection of donor
organs
2. development of rules for deciding on the possibility or undesirableness of donation and
transplantation, taking into account the risks of rejection of donor organs
3. development of a method for supporting the decision on the possibility or undesirableness of
donation and transplantation, taking into account the risks of rejection of donor organs
4. designing the architecture of the cyber-physical system for donor organs' rejection risks
prevention based on donor and recipient health monitoring.</p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>3. Determination of Donor Organs' Rejection Factors</title>
      <p>The main problem with any transplant is the immune response of the recipient's body to the donor
organ (transplant). Acute transplant rejection may occur days or weeks after transplantation. The
immune system can perceive the grafted organ as foreign and attack it, destroying it and leading to
failure.</p>
      <p>The cause of rejection reactions is the different structures of the cell surface. This surface structure
is determined genetically, so each person has their own cell surface structure [19]. For this reason,
relatives are often the most suitable organ donors, as there is increased genetic similarity.</p>
      <p>The donor and recipient must be similar in histocompatibility antigens, which are integrated into
the HLA system (Human leukocyte antigens). The selection of the most compatible donor and the
recipient is based on the results of such a test. Another cross-match test identifies potentially
dangerous antibodies in the recipient that can damage the transplant and lead to donor organ rejection.</p>
      <p>The transfer of donor tissue containing immune cells, especially bone marrow and liver tissue,
often leads to a "reverse" immune response of cells against the host organism - the reaction of
Graftversus-Host-disease [20].</p>
      <p>The current algorithm for the distribution of donor organs does not take into account differences in
the potential survival of donor organs, focuses on waiting times and not on properly weighed medical
factors, which is a major factor in the non-survival of donor organs [8].</p>
      <p>Obtaining a cadaveric organ doubles the patient's chances of survival, but the organ from a living
donor quadruples them. Thus, its initial state is of great importance for the fate of the donor organ.
The corpse origin of the organ is a powerful risk factor for graft dysfunction and reduced survival,
especially against the background of more active use of elderly donors in recent years [21]. For
example, statistics from Catalonia, a world leader in organ donation, show that the average life
expectancy of a patient who has had a cadaveric kidney transplant is 15 years; in the case of a kidney
transplant from a living donor, this period is increased by 10 years.</p>
      <p>The state of health of the recipient at the time of transplantation also programs the further
functioning of the donor organ [21]. For example, active cytomegalovirus infection in the
postoperative period may be the cause of chronic rejection.</p>
      <p>Donor organs from donors under the age of 38 are characterized by better survival (for example,
Figure 1 shows the 10-year survival rate of a transplant received from donors of different ages). The
association between the age of the donor and the function and survival of the donor organ is due to the
fact that the organ from an elderly donor is often characterized by dysfunction due to age-related
diseases [22].</p>
      <sec id="sec-4-1">
        <title>Donor organs transplanted to women are characterized by better survival [21].</title>
        <p>The main reason for the "loss" of the donor organ after transplantation is the progressive chronic
dysfunction of the transplanted organ. According to the literature, if by the end of the first year after
transplantation, for example, kidney transplantation, the number of functioning grafts reaches 90% or
more, then after 10-15 years the number of functioning grafts is only up to 50% [23].</p>
        <p>Immunosuppressive therapy is used to preserve the graft by suppressing the body's immune
response to a foreign organ. Immunosuppressive drugs (cyclosporine, tacrolimus, azathioprine or
mycophenolate, glucocorticoids, antibodies to basiliximab, and anti-thymocyte globulins) are used for
induction therapy - sometimes in high doses. The fixed long-term drug is prescribed as the main
therapy; usually, a combination of steroids and calcineurin inhibitors (cyclosporine or tacrolimus) is
required. Induction therapy with monoclonal antibodies against the interleukin-2 receptor
(basiliximab) or polyclonal antibodies against T-lymphocytes or thymocyte antigens is used for all
indications for transplantation. The analysis revealed a significant difference in graft survival
depending on the type of immunosuppression - between group 1, which received cyclosporine A,
azathioprine, and steroids, and group 3, which received cyclosporine A, mycophenolate mofetil,
steroids, and antibodies to receptor II. In group 1, 5-year survival of renal allograft was 71%; in
groups 2 and 3, the lifespan of renal allograft did not differ - 93% of grafts functioned for 5 years
[24].</p>
        <p>In addition, of great importance in the process of engraftment or rejection of the implant is the
disease that has become an indication for transplantation, as well as its phase. For example, in bone
marrow transplantation, the risk of bone marrow rejection is significantly higher for patients who
were in the acute phase of leukaemia at the time of transplantation [25].</p>
        <p>Therefore, as a result of the study it is possible to form a list of factors that cause the rejection of
donor organs:
1. different surface structure of cells, different blood groups in the recipient and donor
2. incompatibility of the recipient and the donor for HLA antigens
3. high level of dangerous antibodies (cross-match) in the recipient
4. concentration of the used algorithm of distribution of donor organs on waiting time, instead of
on medical factors
5. the origin of the donor organ (posthumous or in life donation)
6. general health of the recipient
7. age of the donor
8. gender of the recipient
9. progressive chronic dysfunction of the transplanted organ after transplantation
10. type of immunosuppressive therapy
11. the disease of the recipient, which became an indication for transplantation, and the phase of
this disease</p>
        <p>Thus, the study revealed the dependence of the process of rejection of donor organs by the
recipient from different surface structures of cells in the recipient and donor, the incompatibility of
recipient and donor for HLA antigens, the level of dangerous antibodies in the recipient, considering
only waiting time in the distribution of donor organs, the origin of the donor organ (cadaveric organ
or organ from a living donor), the general health of the recipient, the age of the donor, the gender of
the recipient, the recipient's disease and its phase that required the transplant, the type of chosen
immunosuppressive therapy, and also from the presence of progressive chronic dysfunction of the
transplanted organ. The established dependencies are useful in the selection of donor organs, as well
as in the appointment of supportive postoperative therapy to minimize the rejection of donor organs
by the recipient.</p>
        <p>Obviously, among the identified list of factors, there are many factors that can be identified by the
cyber-physical system for donor organs' rejection risks prevention based on donor and recipient health
monitoring, after processing data from sensors and donor’s and recipient’s tests – different cell
surface structures (based on the processing of donor's and recipient's tests), different blood groups of
the recipient and donor (based on the processing of donor's and recipient's tests), incompatibility of
recipient and donor by HLA antigens (based on the processing of donor's and recipient's tests), high
level of dangerous cross-match antibodies of the recipient (based on the processing of the results of
the recipient's tests), the general state of health of the recipient (based on the processing of data
obtained from sensors of the cyber-physical system, as well as the results of the recipient's tests). In
addition, the cyber-physical system can be useful in identifying the following risk factors – the origin
of the donor organ (posthumous or in life donation); the age of the donor; gender of the recipient.</p>
      </sec>
    </sec>
    <sec id="sec-5">
      <title>4. Cyber-Physical System for Donor Organs' Rejection Risks Prevention Based on Donor and Recipient Health Monitoring</title>
      <p>Taking into account the above factors that may be identified by the cyber-physical system for
donor organs' rejection risks prevention, let's develop rules for deciding on the possibility or
undesirableness of donation and transplantation, taking into account the risks of donor rejection.</p>
      <p>Rules for deciding on the possibility or undesirableness of donation and transplantation
considering the risks of rejection of donor organs:
1. if the surface structure of donor cells (set SSCd) and recipient cells (set SSCr) coincide, i. e.</p>
      <p>SSCd = SSCr, then f=f+1 and b[1]=0, else b[1]=1
2. if the blood groups of the recipient btr and donor btd coincide, i. e. btr = btd, then f=f+1 and
b[2]=0, else b[2]=1
3. if the HLA antigens of the donor (set HLAd) and the recipient (set HLAr) are compatible, i. e.</p>
      <p>HLAd = HLAr, then f=f+1 and b[3]=0, else b[3]=1
4. if the level of dangerous antibodies (cross-match) in the recipient cmr does not exceed the
established threshold value cmth, i. e. cmr ≤ cmth, then f=f+1 and b[4]=0, else b[4]=1
5. if all indicators of the recipient's health HSr = {hsr1, hsr2,…, hsrn}, obtained from the sensors,
as well as from the results of the recipient's tests, are normal (do not exceed the reference
values), i. e. if hsr1 ≤ hsth1 and hsr2≤ hsth2 and … and hsrn ≤ hsthn, then f=f+1 and b[5]=0, else
b[5]=1
6. if the donor organ has a lifetime origin, then f=f+1 and b[6]=0, else b[6]=1
7. if the age of the donor ar does not exceed the established threshold value ath, i. e. ar ≤ ath, then
f=f+1 and b[7]=0, else b[7]=1
8. if the gender of the recipient is female, then f=f+1 and b[8]=0, else b[8]=1</p>
      <p>Given the peculiarities of the formation of array b, the rules for the formation of recommendations
for the transplantologist on the available risk factors are as follows:
1. if b[1] = 1, the transplantologist is advised to pay attention to the discrepancy between the
surface structure of the donor and recipient cells
2. if b[2] = 1, the transplantologist is advised to pay attention to the differences in blood groups
of the recipient and the donor
3. if b[3] = 1, the transplantologist is advised to pay attention to the incompatibility of HLA
antigens of the donor and recipient
4. if b[4] = 1, the transplantologist is advised to pay attention to the high level of dangerous
antibodies (cross-match) in the recipient
5. if b[5] = 1, the transplantologist is recommended to pay attention to the current state of health
of the recipient (carefully analyze the indicators obtained from system sensors, as well as the
results of tests of the recipient)
6. if b[6] = 1, the transplantologist is recommended to pay attention to the origin of the donor
organ
7. if b[7] = 1, the transplantologist is advised to pay attention to the age of the donor
8. if b[8] = 1, the transplantologist is advised to pay attention to the gender of the recipient
Then the method for supporting the decision on the possibility or undesirableness of donation and
transplantation considering the risks of rejection of donor organs consists of the following steps:
1. training of the system by practicing transplantologists – setting the threshold value cmth of the
level of dangerous antibodies (cross-match) in the recipient; setting a list of all important
indicators of the recipient's health – the formation of the set HS = {hs1, hs2,…, hsn}; setting
reference (threshold) values of all indicators of the health of the recipient HSth = {hsth1,
hsth2,…, hsthn}; setting the threshold age of the donor ath
2. formation of a set of indicators of the recipient's health HSr = {hsr1, hsr2,…, hsrn} on the basis
of data obtained from cyber-physical system sensors, as well as due to semantic analysis of
recipient's tests results with selection of values of required indicators (elements of the set HS
= {hs1, hs2,…, hsn}); formation of sets of surface structure of donor cells (set SSCd) and
recipient (set SSCr) based on semantic analysis of donor's and recipient's tests results with
selection of values of required indicators (elements of the sets SSС); determination of the
blood group of the recipient btr and donor btd on the basis of semantic analysis of the results
of tests of the recipient and donor with the selection of the values of the required indicators
(elements bt); formation of sets of HLA antigens of the donor (set HLAd) and the recipient (set
HLAr) based on semantic analysis of donor's and recipient's tests results with a selection of
values of required indicators (elements of the sets HLA); determination of the level of
dangerous antibodies (cross-match) in the recipient cmr on the basis of semantic analysis of
the results of the recipient's tests with the selection of the values of the required indicator
(element cm); formation of the questions to the transplantologist about the origin of the donor
organ, the age of the donor, and the gender of the recipient
3. analysis of sets of the surface structure of donor cells (set SSCd) and the recipient cells (set
SSCr); blood groups of recipient btr and donor btd; sets of HLA antigens of the donor (set
HLAd) and the recipient (set HLAr); the level cmr of dangerous antibodies (cross-match) in the
recipient; set HSr = {hsr1, hsr2,…, hsrn} of all recipient's health indicators obtained from
system's sensors, as well as from recipient's tests; the origin of the donor organ; age of the
donor; the gender of the recipient – using each of the developed rules for deciding on the
possibility or undesirableness of donation and transplantation considering the risks of
rejection of donor organs – and counting the counter f and filling the array b
4. if f = 8, the conclusion is given on the possibility of donation and transplantation for this case,
as all factors of rejection of donor organs are eliminated or minimized
5. if f ≠ 8 (f &lt; 8), then: a conclusion is given on the undesirableness of donation and
transplantation for this case, as one or a group of factors of rejection of donor organs are
present; the transplantologist is provided with available risk factors that may lead to the
rejection of the donor organ – in accordance with the developed rules for the formation of
recommendations for the transplantologist on the available risk factors</p>
      <p>The developed method for supporting the decision on the possibility or undesirableness of
donation and transplantation considering the risks of rejection of donor organs provides: a conclusion
on the possibility or undesirableness of donation and transplantation for a particular case; in the case
of a conclusion on the undesirableness of donation and transplantation in a particular case - the
formation of recommendations to the transplantologist on the available risk factor(s) in order to make
a final informed decision on whether or not to perform transplant surgery.</p>
      <p>The cyber-physical system for donor organs' rejection risks prevention based on donor and
recipient health monitoring is aimed at verifying the list of factors that cause donor organ rejection.
Based on this verification, the cyber-physical system for donor organs' rejection risks prevention
offers a conclusion on the possibility (if all factors of rejection of donor organs processed by the
system are eliminated or minimized) or undesirableness (if one or a group of rejection factors of
donor organs processed by the system cannot be eliminated) of donations and transplants in one case
or another. In addition, in the case of a decision on the undesirableness of donation and
transplantation in some cases, the cyber-physical system for donor organs' rejection risks prevention
provides the transplantologist with available risk factors that may lead to rejection of the donor organ,
in order to analyse in detail these risk factors by the transplantologist and make a final informed
decision on whether or not to perform transplant surgery.</p>
      <p>The proposed cyber-physical system for donor organs' rejection risks prevention based on donor
and recipient health monitoring is grounded on the developed method for supporting the decision on
the possibility or undesirableness of donation and transplantation considering the risks of rejection of
donor organs, and the rules for deciding on the possibility or undesirableness of donation and
transplantation and the rules for the formation of recommendations for the transplantologist on the
available risk factors.</p>
      <p>The cyber-physical system for donor organs' rejection risks prevention based on donor and
recipient health monitoring includes a set of sensors to measure some indicators that characterize the
current state of health of the recipient – sensors to measure temperature, heart rate, blood oxygen level
(saturation), blood pressure, blood sugar level, skin conductivity and body composition, biopotential
and bioimpedance of the recipient.</p>
      <p>The architecture of the cyber-physical system for donor organs' rejection risks prevention based on
donor and recipient health monitoring is presented in Figure 2.</p>
    </sec>
    <sec id="sec-6">
      <title>5. Results &amp; Discussion</title>
      <p>Let's consider the functioning of the developed method for supporting the decision on the possibility
or undesirableness of donation and transplantation considering the risks of rejection of donor organs and
cyber-physical system for donor organs' rejection risks prevention based on donor and recipient health
monitoring.</p>
      <p>Practicing transplantologists was conducted training of the cyber-physical system, in the result of
which in the systems: setting the threshold value cmth of the level of dangerous antibodies
(crossmatch) in the recipient; setting a list of all important indicators of the recipient's health – the set HS =
{hs1, hs2,…, hsn}; setting reference (threshold) values of all indicators of the health of the recipient –
the set HSth = {hsth1, hsth2,…, hsthn}; setting the threshold age of the donor ath.</p>
      <p>For example, let's consider a case of heart transplantation to a woman from a deceased donor aged 55
years. The recipient woman was connected to sensors of the cyber-physical system for donor organs'
rejection risks prevention based on donor and recipient health monitoring, and a number of tests were
performed on both the recipient and the donor. Indicators were taken from the sensors, as a result of
which part of the elements of the set HSr was filled. Semantic analysis of the results of donor's and
recipient's tests was performed, as a result of which the other part of the elements of the set HSr was
filled in, the sets SSCd and SSCr were formed; elements btr and btd were determined; the sets HLAd
and HLAr were formed; the element cmr was determined; questions to the transplantologist about the
origin of the donor organ, the age of the donor, and the gender of the recipient were formed and
asked, as well as answers were received.</p>
      <p>Analysis of the elements of the set HSr, the sets SSCd and SSCr, elements btr and btd, the sets HLAd
and HLAr, element cmr, the results of the transplant doctor's answers to the system's questions
regarding the origin of the donor organ, the age of the donor, and the gender of the recipient were
conducted using each of the developed rules for deciding on the possibility or undesirableness of
donation and transplantation considering the risks of rejection of donor organs; the counter f is
counted (f=5) and the array b is filled (Table 1).
Because f ≠ 8 (f &lt; 8), then: a conclusion is given on the undesirableness of donation and
transplantation for this case, because a group of factors of rejection of donor organs are present; the
transplantologist is provided with available risk factors that may lead to the rejection of the donor
organ – in accordance with the developed rules for the formation of recommendations for the
transplantologist on the available risk factors, the transplantologist is advised to pay attention to the
differences in blood groups of the recipient and the donor, to the origin of the donor organ and to the
age of the donor. The transplantologist once again analysed these risk factors in detail and made the
final decision not to perform the described transplant surgery.</p>
    </sec>
    <sec id="sec-7">
      <title>6. Conclusions</title>
      <p>Today in Ukraine the problem of transplantation of organs and other anatomical materials to
humans is very acute. Among the reasons hindering the development of transplantation of anatomical
materials to humans in Ukraine is the rejection of donor organs by the recipient's body.
Transplantation activities should be based solely on the Unified State Information System on Organ
and Tissue Transplantation (USIST). The successfully developed and implemented the cyber-physical
system for donor organs' rejection risks prevention based on donor and recipient health monitoring
may be relevant and important for USIST, because it will help decide on the possibility or
undesirableness of donation and transplantation in a given case, taking into account factors of the
donor organs' rejection.</p>
      <p>The conducted review of known cyber-physical systems for health status monitoring showed that,
despite a large number of different solutions, a cyber-physical system for donor organs' rejection risks
prevention based on donor and recipient health monitoring is currently lacking, and existing
cyberphysical systems cannot be used as a subsystem (module) of USIST for deciding on the possibility or
undesirableness of donation and transplantation in a given case, taking into account the factors of
rejection of donor organs. Therefore, the aim of this study is to develop a cyber-physical system for
donor organs' rejection risks prevention based on donor and recipient health monitoring, and the
method on which it will be based.</p>
      <p>The dependences of the process of rejection of donor organs by the recipient's body on one or
another factor have been established. The established dependencies are useful in the selection of
donor organs, as well as in the appointment of supportive postoperative therapy to minimize the
rejection of donor organs by the recipient. Among the established list of factors, there are many
factors that can be identified by the cyber-physical system for donor organs' rejection risks prevention
based on donor and recipient health monitoring, after processing data from sensors and analysis of the
donor’s and recipient’s tests results.</p>
      <p>The developed method for supporting the decision on the possibility or undesirableness of
donation and transplantation considering the risks of rejection of donor organs provides: a conclusion
on the possibility or undesirableness of donation and transplantation for a particular case; in the case
of a conclusion on the undesirableness of donation and transplantation in a particular case - the
formation of recommendations to the transplantologist on the available risk factor(s) in order to make
a final informed decision on whether or not to perform transplant surgery.</p>
      <p>The architecture of the cyber-physical system for donor organs' rejection risks prevention based on
donor and recipient health monitoring is developed. This system is aimed at verifying the list of
factors that cause donor organ rejection. Based on this verification, the cyber-physical system for
donor organs' rejection risks prevention offers a conclusion on the possibility (if all factors of
rejection of donor organs processed by the system are eliminated or minimized) or undesirableness (if
one or a group of rejection factors of donor organs processed by the system cannot be eliminated) of
donations and transplants in one case or another. In addition, in the case of a decision on the
undesirableness of donation and transplantation in some cases, the cyber-physical system for donor
organs' rejection risks prevention provides the transplantologist with available risk factors that may
lead to rejection of the donor organ, in order to analyse in detail these risk factors by the
transplantologist and make a final informed decision on whether or not to perform transplant surgery.</p>
    </sec>
    <sec id="sec-8">
      <title>7. Acknowledgments</title>
      <p>The Ukrainian authors would like to thank the Armed Forces of Ukraine for providing security to
perform this work. This work has become possible only because of the resilience and courage of the
Ukrainian Army.</p>
    </sec>
    <sec id="sec-9">
      <title>8. References</title>
      <p>[1] T. Hovorushchenko, A. Herts, Ye. Hnatchuk, O. Sachenko, Supporting the decision-making
about the possibility of donation and transplantation based on civil law grounds. Advances in
Intelligent Systems and Computing 1246 (2021) 357-376. doi: 10.1007/978-3-030-54215-3_23.
[2] E. Tackmann, S. Dettmer, Measures influencing post-mortem organ donation rates in Germany,
the Netherlands, Spain and the UK: A systematic review. Anaesthesist 68 6 (2019) 377-383. doi:
10.1007/s00101-019-0600-4.
[3] World Health Organization: Transplantation, 2020. URL:
https://www.who.int/topics/transplantation/en.
[4] Law of Ukraine "On the application of transplantation of anatomical materials to man".
Information of the Verkhovna Rada of Ukraine (2018).</p>
    </sec>
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