# Artificial Intelligence, Sensors and Vital Health Signs: A Review
## 3 Review Method  
A systemic review approach was used to minimize bias and to follow a more accurate keyword selection pattern of related research papers. The systemic approach uses some defined search strings to extract closely related articles within the indexed databases. Conducting the Systematic Literature Review  
This phase includes paper selection in two stages; the outcome in \"extracted data, and information synthesizing\". The selection process commenced with the primary articles. In this stage, the search string (vital signs; healthcare; sensors) + (Internet of Things; artificial intelligence) via Google Scholar as the key search engine by focusing on the indexed academic databases such as: \"ACM, Emerald, Hindawi, IEEE, SAGE, Science Direct, Springer, Taylor and Francis, and Wiley\". Additionally, the paper selection process is illustrated in Figure 1 as follows. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**References** & **Article Type** & **Taxonomy** & **Year Covered** \\ \hline [PERSON] et al. [27], 2018 & \multirow{2}{*}{SLR} & “Security in IoT e-healthcare based on the cloud storage” & 2009–2017 \\ \hline [PERSON] and [PERSON] [28], 2019 & \multirow{2}{*}{SLR} & “Big data analytics and fog computing in IoHT” & 2014–2018 \\ \hline [PERSON] et al. [29], 2020 & \multirow{2}{*}{SLR} & “IoT-based healthcare service delivery” & 2010–2018 \\ \hline [PERSON] et al. [30], 2020 & \multirow{2}{*}{SLR} & “User and data interaction in IoHT” & 2018–2019 \\ \hline [PERSON] et al. [31], 2020 & \multirow{2}{*}{SLR} & “Heart monitoring system using IoT” & 2015–2018 \\ \hline [PERSON] et al. [32], 2021 & \multirow{2}{*}{SLR} & “IoT in healthcare” & 2015–2020 \\ \hline [PERSON] et al. [33], 2020 & \multirow{2}{*}{SLR} & Application of AI methods and Vital Signs & 2008–2018 \\ \hline [PERSON] et al. [34], 2021 & \multirow{2}{*}{SLR} & “Deep learning applications for IoT in healthcare” & 2010–2020 \\ \hline [PERSON] et al. [35], 2017 & \multirow{2}{*}{Survey} & “IoT and cloud computing” & Not mentioned \\ \hline [PERSON] et al. [36], 2020 & \multirow{2}{*}{Survey} & “Healthcare IoT” & Not mentioned \\ \hline [PERSON] et al. [37], 2020 & \multirow{2}{*}{Survey} & “Emerging technologies in the future of IoHT” & Not mentioned \\ \hline [PERSON] et al. [38], 2020 & \multirow{2}{*}{Survey} & “Patient’s health monitoring system based on IoT” & Not mentioned \\ \hline Our Study & \multirow{2}{*}{SLR} & AI-IoT and Vital signs in healthcare & 2010–2022 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Summary of related literature on AI/ML applicable to IoHT and vital health signs. * Initial selection: This step includes filtering the \"titles, abstracts, and keywords of potential primary articles\". At this stage, 1245 articles were retrieved, including conference paper proceedings, journal articles, book chapters, books, symposiums, research reports, etc. The search string was applied to address digital databases from 2010 to 2022. * Final selection: In this step, inclusion/exclusion conditions were used to include important articles and exclude irrelevant ones. In the course of the literature search, a wide range of papers related to the IoT in healthcare delivery were obtained, and regardless of the relevant proceedings and other research reports acquired, only articles found in journal citation reports (JCR) indexed databases were considered based on their full text. At the final selection, 137 JCR-indexed articles were retrieved. A summary of related articles classified based on disease category (asthma/chronic obstructive pulmonary disease (COPD), cardiovascular diseases, diabetes, and nutrition) and the respective sensor category is presented in Table 2.  
Figure 1: Article selection process. According to [19], the IoHT comprises layers of interconnected devices with the ability to exchange and process data to improve patient health.