## 2 Literature Review
### The Role of Blockchain Technology in Healthcare Services

Table 1: Detailed applications of blockchain technology in the healthcare sector existing in the literature. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Ref.** & **Usage Field** & **Technologies** & **Data** & **Stakeholders** & **Contribution** \\ \hline
[27] & EHR Management & \
\begin{tabular}{c} Hypeledger Fabric and \\ Ethereum-based blockchain, \\ Federated Learning, Proof of \\ Work, IoT \\ \end{tabular} &
\begin{tabular}{c} Patient diagnoses, treatment \\ plans, vital measurements, IoT \\ device data, and data related to \\ network attacks \\ \end{tabular} & Patients, IoT network & Attack detection and data administrators, & integrity optimization have been achieved in IoT networks. \\ \hline
[28] & EHR Management & \
\begin{tabular}{c} Consortium blockchain, \\ Knapsack algorithm, SHA-256, \\ secure hash algorithm, Load \\ Balancing Mechanism \\ \end{tabular} &
\begin{tabular}{c} Biometric data, critical, medium, \\ and low-priority patient \\ information \\ \end{tabular} & Patient and healthcare providers & Patient and healthcare data processing over other types of data. \\ \hline
[29] & \
\begin{tabular}{c} Health Information \\ Transfer and Management \\ \end{tabular} &
\begin{tabular}{c} Consortium blockchain, P2P \\ network, Digest chain, Merkle \\ tree \\ \end{tabular} & Patient health data & Patient, heatchers and insurance companies & A solution has been developed to reduce the data load on the blockchain network. \\ \hline
[30] & \
\begin{tabular}{c} Health Information \\ Transfer and Management \\ \end{tabular} &
\begin{tabular}{c} Ethereum-based blockchain, AI, \\ IoT, Digital Twins, AR and VR \\ \end{tabular} & Patient health data, medical records & Patient, heatchers and providers, and third parties & Personalized treatments and education were delivered in the metaverse. \\ \hline
[32] & EHR Management &
\begin{tabular}{c} Hyperedger Fabric-based \\ blockchain, Byzantine Fault \\ Tolerance (BFT) consensus \\ algorithm, P2P Network \\ \end{tabular} & Patient health data, medical records & Patient health data, medical organizations & Data privacy and access control have been ensured. \\ \hline
[31] & EHR Management & \begin{tabular}{c} Blockchain based on \\ Hyperledger Fabric, Smart \\ Contracts \\ \end{tabular} & \
\begin{tabular}{c} Patient health data, medical \\ records \\ \end{tabular} &
\begin{tabular}{c} Patients, healthcare \\ providers, insurance \\ companies, and \\ organizations \\ requesting data for \\ medical research \\ \end{tabular} & Effective and secure data sharing has been achieved among healthcare providers. \\ \hline
[33] & EHR Management & \
\begin{tabular}{c} Blockchain based on \\ Hyperledger Fabric, Smart \\ Contracts \\ \end{tabular} &
\begin{tabular}{c} Patient health data, medical \\ records \\ \end{tabular} & Patient and doctor & Patient privacy is protected, unauthorized access to data is prevented, and all data transactions are immutably recorded. \\ \hline
[33] & EHR Management & \
\begin{tabular}{c} Blockchain based on \\ Hyperledger Fabric, Smart \\ Contracts \\ \end{tabular} &
\begin{tabular}{c} Patient health data, medical \\ records \\ \end{tabular} & Patient and doctor & Patient privacy is protected, unauthorized access to data is prevented, and all data transactions are immutably recorded. \\ \hline \end{tabular}
\end{table} 
Table 1. Cont. This literature review on the utilization of digital technologies in cleaning and hygiene processes, as well as blockchain technologies in the health sector, highlights the critical role these technologies play in enhancing healthcare services. Digital technologies applied in hygiene and cleaning processes provide substantial benefits, particularly in maintaining hygiene standards, reducing operational costs, and optimizing business workflows. Similarly, current blockchain applications in the healthcare field offer innovative solutions in areas such as data security, transparency, and traceability.