## 2 Literature Review
### The Role of Blockchain Technology in Healthcare Services  
Lately, blockchain technology has become a cutting-edge solution in healthcare services by providing features that boost transparency and data security while decreasing the reliance on control systems in sector operations. Various studies have explored the applications of blockchain in improving healthcare services. [PERSON] et al. [19] highlighted the significance of technology in safeguarding and organizing healthcare information by creating a mobile health (mHealth) app focused on treating insomnia on smartphones with data security ensured through the Hyperledger Fabric framework and Practical Byzantine Fault Tolerance (PBFT). The application they proposed caters to the data handling requirements of patients and healthcare professionals alike while setting the groundwork for enhancing mHealth apps with blockchain technology. Similarly, [PERSON] et al. [20] in a study on electronic health records (EHRs) implemented a decentralized architecture to guarantee the secure storage and control of data that safeguards patient privacy and enables seamless data exchange between various parties, such as healthcare professionals and insurers. [PERSON] et al. [21] explored how blockchain technology could be utilized for efficient data handling in the healthcare sector specifically focusing on the storage of medical imaging data in a secure and patient-centered manner. They introduced a system that empowers patients to take charge of their health information through easy-to-use mobile and web platforms, giving them greater control over their healthcare data management processes. Similarly, [PERSON] and [PERSON] [22] utilized blockchain infrastructure and QR codes to provide fast and secure access to health data. This system accelerates patient-doctor communication and can be effectively applied in scenarios requiring urgent intervention. [PERSON] et al. [23] analyzed the role of blockchain technology in healthcare supply chains by introducing a model designed to minimize the risks of products at every stage. Starting from production to reaching the patients' hands, this proposed model enhances the tracking of medications to ensure patients receive treatments and improves overall operational effectiveness in healthcare delivery systems. Studies focusing on the integration of blockchain, IoT, and artificial intelligence offer significant perspectives for the development of digital health solutions. For instance, [PERSON] et al. [24] implemented a blockchain system to store health data from wearable devices and offer personalized healthcare services using AI analyses techniques in an innovative way. In a vein of innovation in healthcare technology research by [PERSON] et al., real-timemonitoring systems for diabetic patients have been developed to help individuals manage their health more effectively [25]. Such advancements truly benefit patients, and these systems provide significant advantages for individual patients. Focusing on the secure management of data obtained from IoT devices [26], the proposed system utilizes blockchain technology to ensure the secure handling of electronic health records (EHRs). In this system, blockchain technology is integrated with IoMT devices using a low-cost embedded system. The authors secure healthcare data on the blockchain through encryption. Additionally, [PERSON] et al. [27] combined federated learning and blockchain technologies to provide secure data transmission in IoT networks, thereby enhancing security levels with intrusion detection mechanisms. The framework presented in their study can manage data diversity and heterogeneity in healthcare IoT networks. Studies focusing on improving resource allocation and data sharing in healthcare systems emphasize the capacity of blockchain technology to enhance operational performance. [PERSON] and [PERSON] [28], addressing resource allocation problems in healthcare systems, offered an innovative approach by integrating blockchain technology with the knapsack algorithm.