docs(thesis): add conclusion and fix some things

This commit is contained in:
Julian Lobbes 2023-09-01 03:41:00 +02:00 committed by Julian Lobbes
parent 2131447870
commit a0584b008b
2 changed files with 240 additions and 174 deletions

View File

@ -25,7 +25,7 @@
type=\acronymtype,
name={UI},
description={User Interface},
first={User Interface (GUI)}
first={User Interface (UI)}
}
\newglossaryentry{iot}{
type=\acronymtype,
@ -138,17 +138,17 @@
which may increase access to care and decrease healthcare delivery costs.
}
}
\newglossaryentry{rwm}{
\newglossaryentry{rwsm}{
type=\acronymtype,
name={RWM},
name={RWSM},
description={\Gls{rwm_full}},
first={\Gls{rwm_full} (RWM)}
first={\Gls{rwm_full} (RWSM)}
}
\newglossaryentry{rwm_full}{
name={Remote Warning Score Monitoring},
description={
An approach that integrates \gls{rpm} of mobile patients with the automated calculation of an \gls{ews}.
It enables real-time assessment of patient risk based on data gathered remotely, offering proactive care interventions.
It enables real-time assessment of patient deterioration risk based on data gathered remotely.
}
}
\newglossaryentry{api}{

View File

@ -26,8 +26,8 @@
\usepackage{pdfpages} % PDFs in appendix
\usepackage[toc,nopostdot,nonumberlist,style=altlist,acronym]{glossaries}
\usepackage{algorithm}
\usepackage{algpseudocode}
%\usepackage{algorithm}
\usepackage[vlined]{algorithm2e}
\usepackage{subcaption} % allows multiple figures to share a caption
% Page margins
@ -89,10 +89,21 @@
% Colors
\definecolor{PLRI_Rot}{RGB}{190,30,60}
\definecolor{grau}{RGB}{120,110,100}
% A command which generates a TODO message
\newcommand{\todo}[1]{{\fontfamily{lmtt}\selectfont{\color{orange}\small\underline{TODO:}} \textbf{#1}\normalsize \\}}
% Link colors
\definecolor{linkColor}{RGB}{0,42,112}
\definecolor{citeColor}{RGB}{0,112,47}
\hypersetup{
colorlinks=true, % true: colored links, false: boxed links
linkcolor=linkColor, % color of internal links (change box color with linkbordercolor)
citecolor=citeColor, % color of links to bibliography
filecolor=magenta, % color of file links
urlcolor=cyan, % color of external URLs
linktocpage=true % make page numbers, not text, be link on TOC, LOF and LOT
}
\input{./glossary.tex}
@ -106,9 +117,18 @@
\section*{Summary}
\addcontentsline{toc}{section}{Summary}
The summary should be a guideline for creating the work, and briefly name the findings.
A summary must be written in both English and German.
This research investigated the feasibility of Remote Warning Score Monitoring (RWSM)
for outpatients using commercially available smart medical devices.
A system, named Medwings, was designed, implemented, and evaluated.
A usability study was carried out and found that consumer-grade smart devices can be used to facilitate remote patient monitoring
integrated with Early Warning Scores (EWS).
While the system was largely successful in demonstrating the practicability of RWSM, it also identified
several operational challenges.
The Medwings system shows potential for improving patient quality of life and optimizing healthcare resources.
Despite its current limitations, Medwings opens the door for future research and development,
given the fast-evolving market for advanced smart medical devices.
The study fills a critical knowledge gap and sets the stage for further advancements in the field of remote patient
monitoring with early warning scores.
\newpage
\renewcommand*\contentsname{Table of contents}
@ -119,8 +139,6 @@ A summary must be written in both English and German.
\pagenumbering{arabic}
\section{Introduction}
\todo{brief description of the project}
\subsection{Background}
Clinical \gls{deterioration} is a critical concern in healthcare, particularly for vulnerable populations such as the elderly and chronically
@ -128,14 +146,14 @@ ill patients. It refers to a decline in a patient's health status and may lead t
longer stays in intensive care units, and increased healthcare costs.
The \Gls{ews} has been widely adopted internationally for preemptive detection of deteriorating patients\cite{downey_strengths_2017}.
A large body of scientific evidence validates the effectiveness of \Glspl{ews} in assessing severity of illness, and in predicting adverse clinical events,
such as severe deterioration, likelihood of \gls{icu} admission, and mortality, both in hospital wards\cite{subbe_validation_2001, buist_association_2004, paterson_prediction_2006, gardner-thorpe_value_2006, alam_exploring_2015, bilben_national_2016, brekke_value_2019}
such as severe deterioration, likelihood of \gls{icu} admission and mortality, both in hospital wards\cite{subbe_validation_2001, buist_association_2004, paterson_prediction_2006, gardner-thorpe_value_2006, alam_exploring_2015, bilben_national_2016, brekke_value_2019}
and in ambulatory care \cite{ehara_effectiveness_2019, burgos-esteban_effectiveness_2022, paganelli_conceptual_2022}.
Two commonly used clinical scores are the \Gls{news2} and the
\Gls{mews}\cite{burgos-esteban_effectiveness_2022}.
Both are calculated by capturing various vital parameters from the patient at a specific point in time, followed by numerical aggregation of the
captured data according to the score being used\cite{subbe_validation_2001, noauthor_national_2017}.
For \Gls{mews}, each measured physiological parameter is assigned an individual score based on which range it is in.
For \Gls{mews}, each measured physiological parameter is assigned an individual score based on which range it lies in.
The ranges for scoring each parameter are shown in Table \ref{tab:mews-calculation}.
The individual scores are then added together to produce the final \Gls{mews}.
A MEWS value of 5 or above indicates an elevated risk of death, and likelihood of ICU admission\cite{subbe_validation_2001}.
@ -170,14 +188,14 @@ A MEWS value of 5 or above indicates an elevated risk of death, and likelihood o
\caption{\label{tab:mews-calculation}MEWS calculation ranges}
\end{table}
Traditionally, doctors and nursing staff perform collection and evaluation of the data manually, often inputting data into an EWS-calculator by hand.
Traditionally, doctors and nursing staff perform collection and evaluation of the data manually, often inputting data into \Gls{ews}-calculators by hand.
However, as Eisenkraft et al. mentioned in 2023, \enquote{some known setbacks of the NEWS and other scales are the frequency of scoring and
response, integration into practice, and miscalculation by healthcare providers\ldots~}\cite{eisenkraft_developing_2023}.
\Gls{rpm} can improve deterioration detection\cite{shaik_remote_2023} by greatly reducing the
amount of human interaction required to take measurements and perform \Gls{ews} calculations.
A number of studies have explored \Gls{rpm} combined with automated \Gls{ews} calculation in hospitals\cite{eisenkraft_developing_2023, filho_iot-based_2021, un_observational_2021, karvounis_hospital_2021}.
With hospitals facing overwhelming patient load during the SARS-CoV-2 pandemic, interest in exploring \Gls{rpm} surged to unprecedented heights,
With hospitals facing overwhelming patient load during the SARS-CoV-2 pandemic, interest in exploring \Gls{rpm} surged to new heights,
and \Gls{news2} emerged as an effective tool for predicting severe infection outcomes\cite{filho_iot-based_2021, gidari_predictive_2020, otoom_iot-based_2020, carr_evaluation_2021}
while reducing person-to-person contact during patient monitoring.
@ -192,7 +210,7 @@ in this rapidly evolving field.
\subsubsection{Search strategy}
A systematic search strategy was implemented on the Scopus database, aimed to encompass a broad spectrum of literature relevant
to the use of smart medical devices for automated early warning score monitoring of patients dismissed from ambulant or hospital care.
to the use of smart medical devices for automated early warning score monitoring of outpatients.
The search focused on topics related to the research area, encompassing the examination of \Gls{ews}, hospital admission, care escalation,
and medical emergencies in combination with IT automation, medical wearables and \Gls{iot}.
The Scopus database was chosen for its extensive coverage of scholarly literature across multiple disciplines.
@ -203,8 +221,8 @@ Inclusion criteria:
\begin{itemize}
\item Articles focusing on the utilization of medical wearable devices for remote patient monitoring
\item Articles addressing the automated calculation of early warning scores
\item Articles discussing the application of early warning scores outside of medical care facilities
\item \textit{OR} articles addressing the automated calculation of early warning scores
\item \textit{OR} articles discussing the application of early warning scores outside of medical care facilities
\end{itemize}
Exclusion criteria:
@ -213,14 +231,14 @@ Exclusion criteria:
\item Non-English language articles
\item Publications for which full-text access was not available
\item Duplicate articles
\item Articles outside of the \enquote{Computer Science} subject area
\item Articles unrelated to the \enquote{Medicine}, \enquote{Medical Informatics} or \enquote{Computer Science} subject areas
\end{itemize}
The following Scopus query was used to identify relevant literature:
\begin{tcolorbox}[enhanced, center, width=0.95\linewidth, rounded corners=all, colframe=black!75!white, boxrule=0.5pt, colback=black!5!white]
\begin{lstlisting}[language=SQL]
TITLE-ABS-KEY(("patient" OR "clinical" OR "medical") AND ("deterioration" OR "instability" OR "decompensation" OR "admission" OR "hospitalization" OR "escalation" OR "triage" OR "emergency")) OR ("early warning" OR "early warning score" OR "warning" OR "score*" OR "EWS") AND TITLE-ABS-KEY("system" OR "automat*" OR "smart*" OR "wearable*" OR "internet of thing*" OR "iot" OR "digital" OR "sensor*" OR "signal" OR "intelligen*" OR "predict*" OR "monitor*" OR "sreen*" OR "remote" OR "it" OR "comput*" OR "mobile" OR "5G" OR "network" (("vital*" OR "bio*") AND ("marker*" OR "sign*" OR "monitor*"))) AND TITLE-ABS-KEY("home" OR "domestic" OR "community" OR "remote" OR "longterm" OR "nursing" OR "rehabilitation" OR "outof*hospital" OR "telemedicine" OR "ehealth" OR "mhealth")
TITLE-ABS-KEY(("patient" OR "clinical" OR "medical") AND ("deterioration" OR "instability" OR "decompensation" OR "admission" OR "hospitalization" OR "escalation" OR "triage" OR "emergency")) OR ("early warning" OR "early warning score" OR "warning" OR "score*" OR "EWS") AND TITLE-ABS-KEY("system" OR "automat*" OR "smart*" OR "wearable*" OR "internet of thing*" OR "iot" OR "digital" OR "sensor*" OR "signal" OR "intelligen*" OR "predict*" OR "monitor*" OR "sreen*" OR "remote" OR "it" OR "comput*" OR "mobile" OR "5G" OR "network" (("vital*" OR "bio*") AND ("marker*" OR "sign*" OR "monitor*"))) AND TITLE-ABS-KEY("home" OR "domestic" OR "community" OR "remote" OR "longterm" OR "nursing" OR "rehabilitation" OR "out*of*hospital" OR "telemedicine" OR "ehealth" OR "mhealth")
\end{lstlisting}
\end{tcolorbox}
@ -240,8 +258,8 @@ eligibility in full text.
Finally, after a thorough evaluation, $N=45$ articles were included for the literature review, providing insight into the current state of
research on the use of smart medical devices for automated early warning score monitoring in patients transitioning from ambulant or
hospital care.
Figure \ref{prisma-flowchart} shows the literature assessment process.
The list of reviewed literature is shown in Tables \ref{tab:inclusion-table-1}, \ref{tab:inclusion-table-2} and \ref{tab:inclusion-table-3}.
Figure \ref{prisma-flowchart} shows the screening process.
The complete list of reviewed literature is shown in Tables \ref{tab:inclusion-table-1}, \ref{tab:inclusion-table-2} and \ref{tab:inclusion-table-3}.
\begin{table}[!ht]
\centering
@ -468,14 +486,12 @@ The list of reviewed literature is shown in Tables \ref{tab:inclusion-table-1},
\caption{\label{tab:inclusion-table-3}List of reviewed articles \textit{(Part 3 of 3)}}
\end{table}
% TODO for all outcomes, present and compare the findings of each study
\subsubsection{Discussion}
While the application of \Glspl{ews} in ambulant care facilities and hospitals has been thoroughly investigated,
very little research has been done to assess their practicability for remote monitoring of at-risk patients at home.
Furthermore, it was observed that previous research on the use of \Gls{iot}-devices for this purpose was largely conducted in
experimental settings, limiting the generalizability of the results.
laboratory settings, limiting the generalizability of the results.
Some studies have examined monitoring vital signs of at-home-patients for abnormalities,
however in most of them, no automated EWS calculations were made\cite{archip_iot_2016, azimi_medical_2016, chowdary_efficient_2018, yeri_iot_2020, lee_all-day_2020, athira_design_2020, phaltankar_curaband_2021, thippeswamy_prototype_2021}.
In 2015, Anzanpour et al. developed a monitoring system which collects vitals data and calculates an \Gls{ews}, however due to limited or nonexistent
@ -488,7 +504,7 @@ However, the methodology they used to calculate the \Gls{ews} in real-time with
Recent studies indicate a growing trend towards investigating automated \Gls{ews} calculations in real-world scenarios\cite{downey_strengths_2017, karvounis_hospital_2021, b_v_review_2022, dagan_use_2020}.
Notably, the availability of comprehensive, mobile vital signs monitoring equipment has seen a significant increase, especially in the wake of the SARS-CoV-2
pandemic\cite{paganelli_conceptual_2022, filho_iot-based_2021, otoom_iot-based_2020, gronbaek_continuous_2023}.
This surge in accessibility has paved the way for more extensive and continuous monitoring of patients in non-medical care settings.
This surge in accessibility has paved the way for more extensive remote monitoring of outpatients.
Moreover, there is a growing interest in incorporating machine learning algorithms to enhance the predictive capabilities of
deterioration detection\cite{un_observational_2021, da_silva_deepsigns_2021, de_mello_dantas_data_2020}.
This demonstrates the evolving landscape of remote patient monitoring, aiming to improve clinical outcomes and alleviate the
@ -504,13 +520,13 @@ of an \Gls{ews} specialized for use outside of medical care facilities.
Based on the findings, several key implications can be drawn.
Firstly, the improved availability of smart sensors and the demonstrated effectiveness of \Glspl{ews} in predicting deterioration in direct
medical care settings warrant research into their utilization at home.
By remotely monitoring patients, it may be possible to identify early signs of deterioration, enabling earlier dismissal from
By remotely monitoring patients, it may be possible to identify early signs of deterioration, allowing for earlier dismissal from
hospital care and thereby freeing up valuable resources.
Additionally, this approach holds the potential to reduce mortality rates and minimize the frequency of adverse clinical outcomes.
Additionally, this approach holds the potential to reduce the frequency of adverse clinical outcomes, as well as mortality rates.
However, it is important to acknowledge the lack of research on the use of \Glspl{ews} at home, which calls for a feasibility study in this
specific context.
This study would need to address challenges such as the frequency of measurements required and the absence of immediate diagnosis
Such a study would need to address challenges such as the frequency of measurements required and the absence of immediate diagnosis
from qualified medical staff.
Overcoming these obstacles is essential to ensure the safety and efficacy of automated remote patient monitoring in home-based settings.
@ -523,7 +539,6 @@ non-medical care settings.
\subsection{Motivation}
% TODO EWS makes prediction value better than monitoring abnormalities in single vital signs
Installing and operating traditional continuous monitoring systems, like the vital sign monitors used in medical facilities, demands
specialized equipment and technical expertise.
Furthermore, these systems are cumbersome for patients, as they involve connecting patient and sensor device with numerous electrodes
@ -534,42 +549,49 @@ biometric sensors into one device, allowing for a much higher degree of patient
scalability\cite{un_observational_2021}.
Therefore, utilizing such devices for \Gls{rpm} is a suitable approach.
In summary, with the current availability of wearable, networked biosensors and the validated effectiveness of EWS in medical facilities,
With the current availability of wearable, networked biosensors and the validated effectiveness of \Glspl{ews} in medical facilities,
combining both aspects presents an important and interesting research opportunity which could help reduce mortality and improve clinical
outcomes for patients at risk of deterioration, both in their homes and on the go.
\subsection{State of the problem}
% Merge with Motivation?
% There is a lack of software calculating MEWS with RPM
The rapid advancements in wearable, networked biosensors have expanded the horizons of \Gls{rpm}.
Still, their integration with \Glspl{ews} remains under-explored, especially for outpatients or those outside traditional medical care settings.
Still, their integration with \Glspl{ews} remains under-explored, especially for outpatients or those outside of traditional medical care settings.
While \Glspl{ews} have proven effective in hospitals and ambulant care facilities, the practicality of implementing them remotely, under real-life conditions,
leveraging state-of-the-art smart medical devices, remains uncertain.
Existing research on \Gls{rpm} predominantly focuses on the technology's capability for vitals monitoring, often sidelining the integration and automated calculation of \Glspl{ews}.
Consequently, there is a knowledge gap concerning the system's effectiveness, feasibility, and challenges when deployed in everyday environments,
particularly in patients' homes or during their daily routines.
There is a lack of available software which integrates \Gls{rpm} with \Glspl{ews} while being feasible for everyday use,
as well as a general knowledge gap in exploring the usefulness of this approach.
Existing research on \Gls{rpm} predominantly focuses on the technology's capability for vitals monitoring and often sidelines
the integration and automated calculation of \Glspl{ews}.
This results in a knowledge gap concerning the effectiveness, feasibility, and design challenges of a system which combines both concepts.
Moreover, there is a lack of available software which integrates \Gls{rpm} with \Glspl{ews} aimed at everyday use by patients.
\subsection{Research goals}
The objective of this research was to explore \gls{rwm}: remote monitoring of patients dismissed from direct medical care using an \Gls{ews}.
The objective of this research is to explore \gls{rwsm}: remote monitoring of patients dismissed from direct medical care using automated \Gls{ews}
assessments.
Specifically, the following questions were asked:
Specifically, the following questions are asked:
\begin{itemize}
\item Is \Gls{rwm} practically feasible using smart medical devices commercially available today?
\item Can existing, validated \Glspl{ews} be utilized in \Gls{rwm}?
\item What are the technical and operational challenges of implementing an \Gls{rwm} system designed for daily use?
\item Can an \Gls{rwsm} system, feasible for everyday use, be implented using smart medical devices commercially available today?
\item What are the technical and operational challenges of implementing such a system?
\item Can existing, validated \Glspl{ews} be utilized in \Gls{rwsm}?
\end{itemize}
\subsection{Tasks}
The research questions stated above were pursued by designing, implementing and deploying an \Gls{rwm} system, followed by a usability study and subsequent evaluation
of the attained knowledge.
The research questions stated above were pursued by designing, implementing and deploying an \Gls{rwsm} system
which utilizes a clinically validated \Gls{ews}, followed by a feasibility study examining its everyday use,
and a subsequent evaluation of the study.
An outline of the steps taken to carry out this investigation is shown here:
A detailed outline of each step taken to carry out this investigation is shown here:
\begin{enumerate}
\item \textbf{EWS selection:} identification of an \Gls{ews} which is:
@ -586,86 +608,77 @@ An outline of the steps taken to carry out this investigation is shown here:
\item offer user-friendly, non-intrusive measurement procedures, suitable for the patient to use at home and on the go
\item allow secure and automated retrieval of the vitals data needed to calculate the chosen \Gls{ews} via an \Gls{api}
\end{itemize}
\item \textbf{System design and implementation:} development of a software application facilitating \Gls{rwm} using the selected medical devices, ensuring:
\item \textbf{System design and implementation:} development of a software application facilitating \Gls{rwsm} using the selected medical devices, ensuring:
\begin{itemize}
\item regular vitals data capture from patients
\item accurate calculation of the chosen \Gls{ews} based on captured data
\end{itemize}
\item \textbf{Real-world usability trial:} conduction of a trial, wherein a test subject utilizes the implemented system in real-world conditions,
collecting data useful for system evaluation.
\item \textbf{Evaluation:} methodical review of the implemented \Gls{rwm} system:
\item \textbf{Evaluation:} methodical review of the implemented \Gls{rwsm} system:
\begin{itemize}
\item Analysis regarding the effectiveness of the system in consistently gathering \Gls{ews} samples
\item Investigation of failure points when \Gls{ews} sample retrieval was unsuccessful
\item Analysis of the effectiveness of the system in regularly gathering vitals data and \Gls{ews} samples
\item Investigation of failure points when sample retrieval or \Gls{ews} assessments were unsuccessful
\item Collation of the subject's feedback on user experience
\end{itemize}
\item \textbf{Feasibility and challenge discussion:} reflection on the entire research process to:
\begin{itemize}
\item draw conclusions on the feasibility of \Gls{rwm} using modern smart medical sensors
\item discuss application of the chosen \Gls{ews} for \Gls{rwm}
\item draw conclusions on the feasibility of \Gls{rwsm} using modern smart medical sensors
\item discuss application of the chosen \Gls{ews} for \Gls{rwsm}
\item highlight the identified technical and operational challenges
\end{itemize}
\end{enumerate}
By completing these tasks, the research provided a comprehensive understanding of the practicality and potential pitfalls
of \Gls{rwm} in everyday settings, using current technology.
of \Gls{rwsm} in everyday settings, using current technology.
\subsection{Structure}
%\subsection{Structure}
\todo{Describe the structure of the work.}
% TODO Describe the structure of the work
% TODO Describe used notations
\newpage
\section{Medwings}
Three widely used \Glspl{ews} for deterioration are the \Gls{pews}\cite{monaghan_detecting_2005}, \Gls{news2}\cite{noauthor_national_2017} and \Gls{mews}\cite{subbe_validation_2001}.
The initial step in conceptualizing an \Gls{rwsm} system was to choose an appropriate \Gls{ews} to use for patient health evaluation.
Three widely used \Glspl{ews} emerged as potential candidates: the \Gls{pews}\cite{monaghan_detecting_2005}, \Gls{news2}\cite{noauthor_national_2017}
and \Gls{mews}\cite{subbe_validation_2001}.
All three are established as being effective in predicting clinical deterioration.
\Gls{pews} was excluded due to its application being limited to pediatric patients.
Among other factors, \Gls{news2} takes into account whether a patient is currently suffering from hypercapnic respiratory failure, and whether or not the
The choice between \Gls{mews} and \Gls{news2} was made by considering the input parameters to each score's calculation:
compared to \Gls{mews}, \Gls{news2} takes into account whether a patient is currently suffering from hypercapnic respiratory failure, and whether or not the
patient is currently being ventilated using supplemental oxygen.
These parameters are generally not applicable to patients dismissed from medical care, hence \Gls{mews} was chosen as the early warning score
for the envisioned \Gls{rwm} system.
These parameters are generally not applicable to patients dismissed from medical care, hence \Gls{mews}
was chosen as the early warning score for the envisioned \Gls{rwsm} system.
To calculate \Gls{mews}, the following vital signs must be captured and processed by the system:
To calculate the \Gls{mews}, the following vital parameters must be recorded and processed:
\begin{itemize}
\item Heart Rate
\item Blood Pressure (systolic)
\item Body Temperature
\item Respiratory Rate
\item \Gls{avpu} Score
\item \Gls{avpu}
\end{itemize}
To develop an \Gls{rwm} system capable of gathering these vital signs and making them accessible remotely,
networked vitals measurement devices were used.
To develop an \Gls{rwsm} system capable of gathering these vital signs and making them accessible remotely,
wirelessly networked vitals measurement devices were used.
The process of selecting the right smart sensors presented a series of challenges.
A significant portion of the available medical sensors on the market were either not accessible to the general public, or are not distributed
in the geographic area where the research was carried out.
While considering devices that met the procurement criteria outlined earlier, a large number of products had to be excluded due to
constraining patient mobility within or beyond the confines of the patient's home.
Several promising devices were still undergoing development and had not yet received clinical approval, drastically limiting
the pool of viable options.
While considering devices that met the procurement criteria outlined earlier, a large number of products had to be excluded, as they
would have constrained patient mobility to the confines of their home or bedside.
Several promising devices were identified, but dismissed due to still being in active development and having not yet received
clinical approval.
Among the shortlisted options, Withings emerged as the most feasible choice for several reasons.
Notably, they were the only manufacturer that offered a publicly accessible \Gls{api}, allowing for automated retrieval of vitals data.
Consequently, the following three devices were selected for the study:
\begin{itemize}
\item \textit{Withings Scanwatch}\cite{noauthor_worlds_nodate} -- a smart watch capable of, among other things, measuring:
\begin{itemize}
\item \Gls{ecg}
\item \Gls{spo2}
\end{itemize}
\item \textit{Withings BPM Core}\cite{noauthor_bpm_nodate} -- a digital blood pressure measurement cuff used to measure:
\begin{itemize}
\item Blood Pressure
\item Heart Rate
\end{itemize}
\item \textit{Withings Thermo}\cite{noauthor_smart_nodate} -- a contactless digital thermometer for measuring:
\begin{itemize}
\item Body Temperature
\end{itemize}
\end{itemize}
A picture of each device is shown in Figure~\ref{fig:withings-devices}.
Among a few options on the final shortlist, Withings emerged as the most feasible choice for several reasons.
Notably, they were the only manufacturer who offers a publicly accessible \Gls{api}, allowing for automated retrieval of vitals data.
Consequently, three Withings devices were selected for the study.
The \textit{Withings Scanwatch}\cite{noauthor_worlds_nodate}, shown in Figure~\ref{fig:withings-scanwatch} is a smartwatch capable of
measuring a user's \Gls{ecg} and \Gls{spo2} among other things.
A \textit{Withings BPM Core}\cite{noauthor_bpm_nodate}, displayed in Figure~\ref{fig:withings-bpm-core}, was also procured.
It is a digital blood pressure meter capable of recording blood pressure and heart rate.
The third and last device used was a \textit{Withings Thermo}\cite{noauthor_smart_nodate}, a contactless digital thermometer
used to measure body temperature. A picture of a Whithings Thermo can be seen in Figure~\ref{fig:withings-thermo}.
\begin{figure}[!ht]
\begin{center}
@ -694,12 +707,17 @@ A picture of each device is shown in Figure~\ref{fig:withings-devices}.
\end{center}
\end{figure}
Notably, the AVPU score could not be measured, because it typically necessitates a clinical assessment.
Furthermore, the inclusion of the Withings Scanwatch came with a notable limitation.
Although the device possesses the capability to measure a patient's respiration rate, this functionality is restricted to nocturnal measurements during sleep.
All three devices are able synchronize vitals data with the Withings Cloud over the internet, as they connect to the user's phone
using a mobile application provided by Withings.
The chosen selection of devices allows measurements and programmatic access to the vital parameters required to determine a
\Gls{mews}, with some caveats: the AVPU score cannot be measured remotely, as it necessitates a clinical assessment from medical
staff.
Additionally, the inclusion of the Withings Scanwatch came with a notable limitation: although the device possesses the capability
to measure a patient's respiration rate, this functionality is restricted to nocturnal measurements, taken while the user is asleep.
After consulting with several medical professionals, a decision was made to forgo the traditional respiration rate measurement, as well as the AVPU parameter in the \Gls{mews} calculation.
Instead, we introduced a custom \textit{respiration score}, shown in Table~\ref{tab:respiration-score}, which represents any shortness of breath reported by the patient.
Instead, a custom \textit{respiration score} was introduced, shown in Table~\ref{tab:respiration-score}, which represents any shortness of breath reported by the patient.
\begin{table}[!ht]
\centering
@ -722,7 +740,7 @@ To replace the respiration rate in the \Gls{mews} calculation, we took into acco
\subsection{Requirements}
Following the selection of an \Gls{ews} and suitable medical sensors, a comprehensive \Gls{rwm} application was conceptualized,
Following the selection of an \Gls{ews} and suitable medical sensors, a comprehensive \Gls{rwsm} application was conceptualized,
dubbed as the \textit{Mobile Early Deterioration Warning System (Medwings)}.
Prior to its development, several key software requirements for the application were determined.
@ -731,23 +749,27 @@ Prior to its development, several key software requirements for the application
\begin{description}
\item[User Authentication:] Medwings must provide a robust user authentication and authorization system to ensure confidentiality of sensitive patient data, while preventing
unauthorized access to restricted information.
\item[Portability:] Patients must be able to access Medwings from their mobile phone. Enabling access from other types of end user devices is desirable.
\item[Data Collection:] The application must be capable of collecting and storing vital sign readings from all three Withings smart medical sensors without manual
interaction. Additionally, it must be able to prompt patients on whether they are experiencing shortness of breath, and store the response.
\item[Measurement prompts:] The application must regularly prompt patients to take vital sign readings.
\item[Portability:] Patients must be able to access Medwings from their mobile phone.
Enabling access from other types of end user devices is also desirable.
\item[Data Collection:] The application must be capable of collecting and storing vital sign readings from all three
Withings smart medical sensors without the need to transfer data manually.
Additionally, it must be able to determine the custom respiration score introduced earlier, by prompting patients
on whether they are experiencing shortness of breath.
\item[Measurement prompts:] To facilitate a regular \Gls{mews} assessment schedule, the application must regularly
prompt patients to take vital sign readings.
\item[MEWS Calculation:] When sufficient vital signs for a patient are collected, Medwings must automatically compute and store the \Gls{mews}.
\item[Data Synchronization:] Vitals data, \Gls{mews} measurements and any associated metadata should be synchronized and accessible on
each of the patient's end devices. The captured data should be stored for later analysis.
\item[Data Visualization] Patients should be able to view a history of recorded vitals and \Gls{mews} measurements.
each of the patient's end devices. Captured data should be stored by the system for later analysis.
\item[Data Visualization] Patients should be able to view a history of their recorded vitals and \Gls{mews} values.
\end{description}
\subsubsection{Non-functional Requirements}
\begin{description}
\item[Usability:] Medwings should be intuitive and user-friendly, requiring minimal technical expertise from the end-user.
User interfaces should be adaptive for display on both mobile displays and larger monitors.
If measurements or user interactions are invalid, error messages should be displayed to the user.
\item[Availability:] The system should be available for patients to use at all times, with minimal downtime.
\item[Usability:] Medwings should be intuitive and user-friendly, requiring minimal technical expertise from end-users.
The \Gls{ui} should be adaptive for display on both mobile displays and larger monitors.
If measurements fail or errors occur, clear error messages should be displayed to the user.
\item[Availability:] The system should be available for patients to use at all times, and from any location, with minimal downtime.
\item[Data Validity:] Vitals records retrieved from the smart sensor devices must be converted and displayed correctly.
Calculated \Gls{mews} values must be correct and take into account all relevant vital parameters:
\begin{itemize}
@ -757,10 +779,11 @@ Prior to its development, several key software requirements for the application
\item \Gls{spo2}
\item respiration score
\end{itemize}
When such a set of vitals measurements is used to calculate a \Gls{mews}, the time of measurement for any two
measurements in the set cannot be further apart than ten minutes
\item[Security:] All personal and medical data should be stored securely and. Data in transit must be encrypted at all times.
The identity of clients and servers must be cryptographically verifiable.
To ensure the medical validity of a \Gls{mews} assessment, when a set of vitals measurements is used to calculate a \Gls{mews},
the time of measurement for any two measurements in the set must not be further apart than ten minutes.
\item[Security:] All personal and medical data must be handled in a secure manner, both during storage and in transit.
When transmitting data between Medwings and Withings, or between a user's end device and Medwings, communication confidentiality
and integrity must be ensured. The identity of both communication partners must be cryptographically verifiable.
\end{description}
\subsection{Design and Implementation}
@ -770,18 +793,20 @@ Opting for this format offers several advantages: the primary benefit is its inh
on a wide range of devices such as mobile phones and personal computers.
Adhering to the classic client-server paradigm, the Medwings design prioritizes centralized data storage and processing.
This architecture was found to be benificial for ensuring efficient data synchronization, secure authentication,
and high system availability.
This architecture was found to be benificial for simplifying data synchronization, facilitating secure authentication,
and ensuring high system availability.
Django, a high-level Python web framework, was employed to develop both the frontend and backend components of the Medwings application.
One of the primary motivations for selecting Django was its out-of-the-box user authentication and session management capabilities.
Such features substantially expedited the development process, freeing up time and resources to focus on the unique, medically-oriented functionalities of Medwings.
Some of the primary motivations for selecting Django were its out-of-the-box user authentication and session management capabilities.
Such features substantially expedited the development process, freeing up time and resources to focus on the more unique functionalities
of the Medwings web application.
Furthermore, Django's integrated Object-Relational Mapping (ORM) system greatly simplified the creation, management, and querying of the application's database.
This was pivotal given the essential role of the database in storing vitals data.
While web applications offer many advantages, one limitation is their inability to support push notifications directly to the patient's mobile phone.
To address this gap, a separate push notification microservice was deployed and integrated with Medwings.
Considering the time constraints, this approach proved to be an effective compromise.
While web applications offer many advantages, one limitation is their increased design complexity required to support push
notifications directly on the patient's mobile phone.
To simplify this aspect of the design, a separate push notification microservice was deployed on premise and integrated with Medwings.
Considering the time constraints under which the application was developed, this approach proved to be an effective compromise.
\subsubsection{Architecture}
@ -797,14 +822,14 @@ The overall system environment is shown in Figure~\ref{fig:components-macro}, de
\begin{enumerate}
\item A patient receives a notification on their mobile phone, prompting them to take vitals measurements.
\item Upon opening the notification, they are redirected to the Medwings website.
Here, they are prompted to self-assess their respiration score by answering a short questionnaire, followed by a prompt to take one measurement
on each smart medical device.
\item Upon completion of the measurement, each device transmits the data via Bluetooth to the Withings mobile app, installed on the user's phone.
Here, they are prompted to self-assess their respiration score by answering a short questionnaire,
followed by a prompt to take one measurement on each Withings device.
\item When a measurement is completed, each device transmits the data via Bluetooth to the Withings mobile app, installed on the user's phone.
The mobile app now sends the data to the Withings Cloud for storage.
\item A backend process on the Medwings server awaits the arrival of all recorded measurements from the Withings Cloud, storing them upon reception.
Once all required vitals measurements have been retrieved, the MEWS is calculated, stored and displayed to the patient.
\end{enumerate}
Measurement prompt notifications are dispatched to the patient at regular intervals throughout the day.
Throughout the day, measurement prompt notifications are dispatched to the patient at regular intervals.
\subsubsection{Modules}\label{sec:modules}
@ -822,14 +847,17 @@ Each module defines classes representing backend logic, database schemas and use
Implementation details are encapsulated within these classes, while public interfaces are exposed to external program code to provide each module's core functionality.
The \code{core} module forms the backbone of the application.
It encompasses configuration settings, secrets such as private encryption keys or API tokens, and functionalities shared across multiple other modules.
It encompasses configuration settings, handling of secrets such as private encryption keys or API tokens, and functionalities
shared across multiple other modules.
This includes backend utility functions and shared \Gls{ui} components for the frontend.
Medwings interfaces with the Withings Cloud through the \code{withings} module.
This includes retrieving vitals data through authenticated requests to the Withings Cloud API, which implements the OAuth 2.0 Authorization Framework.
Responsibilities include retrieving vitals data through authenticated requests to the Withings Cloud API, which implements the OAuth 2.0 Authorization Framework.
As per its specification, \enquote{In OAuth, the client requests access to resources controlled by the resource owner and hosted by the resource server\ldots~
Instead of using the resource owners credentials to access protected resources, the client obtains an access token\ldots~
The client uses the access token to access the protected resources hosted by the resource server.
}\cite{hardt_oauth_2012}
% TODO explain this in more detail. It is unclear what is happening here.
While this process is largely transparent for the resource owner --- the patient in this case --- the communication between
Medwings as the resource client and Withings as the resource server is complex, and is therefore abstracted by the module.
Aside from OAuth 2.0, \code{withings} also encapsulates fetching, parsing, and storing vitals data retrieved from Withings.
@ -842,7 +870,7 @@ The registration occurs in three stages:
Figures \ref{fig:ui-register-init} and \ref{fig:ui-register-oauth2}.
\item A registration form, displayed in Figure~\ref{fig:ui-register-continue}, is shown, prompting the user to choose a username and password, and to enter relevant personal information.
\item The user is shown a confirmation that the account was created successfully, and is asked to download the Gotify app, described below, and log in using their Medwings credentials.
Figure \ref{fig:ui-register-finalize} shows the finalization step.
Figure \ref{fig:ui-register-finalize} shows this final step.
\end{enumerate}
Following registration, the supplied information and numerous authentication tokens are saved in the Medwings database.
The patient can now log in to the Medwings website and begin using the system to take vitals and \Gls{mews} measurements.
@ -883,42 +911,67 @@ The patient can now log in to the Medwings website and begin using the system to
The \code{medwings} module, pivotal to the core functionalty of Medwings, defines the data model used to represent and store the various vital signs handled by the application.
Furthermore, it provides interfaces to access the data, as well as the algorithm used to calculate the MEWS, which is listed in Algorithm~\ref{algo:mews}.
% TODO add some more text here
\begin{algorithm}
\begin{algorithmic}[1]
\Procedure{CalculateMews}{$bp, temp, hr, spo2, resp\_score$}
\State $mews\_value \gets 0$
\If{$bp \leq 70$} \State $mews\_value \gets mews\_value + 3$
\ElsIf{$bp \leq 80$} \State $mews\_value \gets mews\_value + 2$
\ElsIf{$bp > 100$ \textbf{and} $bp \geq 200$} \State $mews\_value \gets mews\_value + 2$
\EndIf
\If{$hr < 40$ \textbf{or} $hr \geq 130$} \State $mews\_value \gets mews\_value + 2$
\ElsIf{$hr \leq 50$ \textbf{or} $hr \leq 110$} \State $mews\_value \gets mews\_value + 1$
\EndIf
\If{$resp\_score = 1$} \State $mews\_value \gets mews\_value + 1$
\ElsIf{$resp\_score = 2$} \State $mews\_value \gets mews\_value + 2$
\EndIf
\If{$spo2 < 90$} \State $mews\_value \gets mews\_value + 2$
\ElsIf{$spo2 < 95$} \State $mews\_value \gets mews\_value + 1$
\EndIf
\If{$temp < 35$ \textbf{or} $temp > 38.4$} \State $mews\_value \gets mews\_value + 2$
\EndIf
\State \Return $mews\_value$
\EndProcedure
\end{algorithmic}
\caption{\label{algo:mews}Medwings MEWS calculation}
\end{algorithm}
\begin{centering}
\begin{tcolorbox}[
enhanced, width=0.9\linewidth, boxrule=1pt, arc=4pt,
]
\begin{algorithm}[H]
\KwIn{$blood\_pressure\_systolic$, $body\_temperature$, $heart\_rate$, $spo2$, $respiration\_score$}
\KwOut{$mews$}
\DontPrintSemicolon
\BlankLine
$mews \leftarrow 0$ \;
\BlankLine
\If{$blood\_pressure\_systolic \leq 70$}{
$mews \leftarrow mews + 3$ \;
}\ElseIf{$blood\_pressure\_systolic \leq 80$}{
$mews \leftarrow mews + 2$ \;
}
\ldots \;
\tcp*[l]{systolic blood pressure, body temperature}
\tcp*[l]{and heart rate as per Table~\ref{tab:mews-calculation}}
\BlankLine
\BlankLine
\BlankLine
\If{$respiration\_score = 1$}{
$mews \leftarrow mews + 1$ \;
}\ElseIf{$respiration\_score = 2$}{
$mews \leftarrow mews + 2$ \;
}
\BlankLine
\If{$spo2 \leq 90$}{
$mews \leftarrow mews + 2$ \;
}\ElseIf{$spo2 < 95$}{
$mews \leftarrow mews + 1$ \;
}
\BlankLine
\Return $mews$
\BlankLine
\BlankLine
\BlankLine
\caption{\label{algo:mews}Medwings \Gls{mews} calculation}
\end{algorithm}
\end{tcolorbox}
\end{centering}
In order to send push notifications to mobile devices, Medwings leverages \textit{Gotify} -- a dedicated notification microservice\cite{noauthor_gotify_nodate}.
Gotify is composed of a web server component, and a mobile app acting as the client software.
The server exposes its own API, which allows external applications like Medwings to dispatch push notifications programmatically.
The server exposes its own \Gls{api}, which allows external applications like Medwings to dispatch push notifications programmatically.
It uses an independent database for client authentication. The \code{gotify} module ensures synchronization between the user databases of Gotify and Medwings.
In addition, the module provides interfaces to send customized push notifications to specific patients.
\subsubsection{User Interface}
The Medwings \Gls{ui} was developed with specific design goals in mind to ensure an efficient and intuitive user experience.
Figure \ref{fig:ui-screenshots} provides some impressions from a user's perspective.
Figure \ref{fig:ui-screenshots} provides some impressions of what a user sees when using the application.
\begin{figure}[!ht]
\begin{center}
@ -968,7 +1021,7 @@ Animations are sparingly used to visually indicate in-progress system states, su
\subsubsection{Datamodel}
A relational database is used to store application data, whereby each Medwings module defines the database schema for the underlying data it is responsible for handling.
A relational database was used to store application data, whereby each Medwings module defines the database schema for the underlying data it is responsible for handling.
Module interdependencies correlate closely with the foreign key references in the data model.
A holistic representation of the Medwings data model is shown in Figure~\ref{fig:datamodel}.
@ -1019,26 +1072,26 @@ while still operating within the rate limit.
A MEWS calculation should represent the patient's overall physiological state at -- ideally -- a discrete point in time.
Naturally, there is a delay from when a measurement is taken with a device until it can be retrieved from the API.
The percieved transmission delay in the Medwings implementation was generally consistent with what is stated in the Withings public API documentation:
The transmission delays are mentioned in the Withings public API documentation:
\enquote{Delays are typically less than two minutes, but it can be longer.}\cite{noauthor_keep_nodate}.
However, in some cases, the measurements taken on a device do not get pushed to the Withings Cloud until much later, or fail to do so at all.
While the cause for these longer than normal delays and missing data points is unknown and outside of the control of Medwings, these edge cases
had to be taken into account.
Furthermore, the time it takes a patient to take measurements using all three devices must also be accounted for.
Therefore, Medwings enforces a maximum allowed time difference of ten minutes between measurements of the different vitals records used to calculate MEWS.
If a set of vitals measurements is, across all records in the set, spaced further apart than ten minutes, no MEWS record is calculated, and the user is shown an
error message, prompting them to repeat the measurements.
However, in some cases, the measurements taken on a device do not get pushed to the Withings Cloud until much later.
While the cause for these longer than normal delays and missing data points is unknown and outside of the control of Medwings,
these edge cases had to be taken into account.
The time it takes a patient to take measurements using all three devices must also be accounted for.
Therefore, Medwings enforces a maximum allowed time difference of ten minutes between measurements of the different
vitals records used to calculate the \Gls{mews}.
If a set of vitals measurements is, across all records in the set, spaced further apart than ten minutes, no \Gls{mews} record
is calculated, and the user is shown an error message.
\newpage
\section{System test and trial}
Following the development and deployment of the application, Medwings underwent a performance and usability study.
Over the course of one week, a test subject, impersonating a patient, used the application several times a day.
Each day, five notifications were dispatched every three hours, starting at 10 AM.
Each day, five notifications were dispatched.
Starting at 10 AM, one notification was sent every three hours.
When prompted by a notification, the subject was asked to visit the Medwings website and begin the measurement process.
Following a notification, the measurement process was carried out in the following order:
Following a notification, the measurements were carried out in the following order:
\begin{enumerate}
\item The subject responds to a Medwings prompt to assess their respiration score.
@ -1048,7 +1101,7 @@ Following a notification, the measurement process was carried out in the followi
\item Finally, the subject allows time for Medwings to aggregate all the data and display the \Gls{mews}.
\end{enumerate}
Throughout this process, Medwings would continuously attempt to retrieve the vital sign readings from the Withings cloud, and calculate the
Throughout this process, Medwings would continuously attempt to retrieve the vital sign readings from the Withings Cloud, and calculate the
\Gls{mews} once all required readings are available.
If not all readings could be retrieved within the ten minute timeout, Medwings displayed an error message and aborted the \Gls{mews}
measurement process.
@ -1304,7 +1357,7 @@ Vendor dependence in general introduces a risk to Medwings' continued operation.
Service outages, discontinued device updates, or the vendor ceasing business operations all render the smart devices, and consequently Medwings, unusable.
Vendor-independent access and open-source firmware for the medical devices would mitigate these risks and open up exciting possibilities for further system integrations.
Additionally, expanding the range of monitored vitals could allow implementation of more comprehensive \Gls{rwm} techniques.
Additionally, expanding the range of monitored vitals could allow implementation of more comprehensive \Gls{rwsm} techniques.
The integration of a smart device capable of accurately measuring the respiration rate of a mobile patient would refine the \Gls{mews} calculations,
leading to a more accurate deterioration monitoring system.
The system could also benefit from real-time alerting for emergency situations, rather than relying solely on periodic \Gls{mews} calculations.
@ -1322,20 +1375,33 @@ As technology advances, future work could explore machine learning models to pre
\newpage
\subsection{Implications and Conclusions}
\begin{itemize}
\item Implications of this research for the wider field of remote patient monitoring
\item Conclusions drawn from the research
\item Summary of the contributions of your work
\end{itemize}
Overall, the study has successfully identified key operational successes and challenges, which can be instrumental for future development and refinement of the system.
The objective of this research was to explore the feasibility and of an \gls{rwsm} system for use by outpatients, using
commercially available smart medical devices.
The Medwings system was successful in demonstrating the feasibility of such an approach.
Key operational challenges and successes were identified, providing insights for the future development
and refinement of systems in this domain.
The Medwings system successfully demonstrated the feasibility of remote patient monitoring using consumer-grade smart devices.
While limitations such as synchronization failures and user compliance exist, the system holds promise for continuous, non-intrusive health monitoring, particularly in a home setting.
Further research and development are required to address its current limitations and expand its capabilities.
The research found that \gls{rwsm} is feasible.
While the \Gls{mews} could not be directly applied in its unaltered form,
the use of consumer-grade smart devices in the Medwings system
successfully facilitated remote patient monitoring in combination with \Gls{ews} assessments.
% Usability for potential medical staff, if applicable
% Not perfect, but people can get sent home earlier
Given the rapidly evolving market for advanced smart medical devices, the implications for healthcare providers are significant.
Potentially freeing up medical resources and improving patient mobility and autonomy by allowing for earlier dismissal of patients
from care facilities, systems such as Medwings may hold considerable value.
While the Medwings system has demonstrated the feasibility of \gls{rwsm},
it remains somewhat rough around the edges.
Continued research in this area is essential to enhance the robustness and effectiveness of \Gls{rwsm} systems.
The potential for life-saving interventions via automated alerts makes the case for a more robust system compelling.
Although the current system uses a web-based client-server architecture, alternative approaches should be explored.
Research into the development of a local, body-area-network system could offer improved reliability and responsiveness.
In conclusion, the research has successfully filled an important knowledge gap in the field of remote patient monitoring
with early warning scores, and outlines the scope for future advancements.
Given the continuing technological advancements in smart medical devices, the future appears promising for the adoption and refinement
of systems like Medwings for better patient care and resource optimization in healthcare.
\newpage
% TODO adjust: carry on from TOC