# A Review of Blockchain Technology Applications in Ambient Assisted Living
## 3 Results
### Patient Monitoring and Intervention  
Integrating IoT with blockchain technology is used to develop decentralized ambient monitoring and intervention infrastructures using IoT devices (see Table 3). The data provided by the IoT devices can be stored on the blockchain as transactions and replicated in all the nodes of the network. The blockchain can offer an efficient environment for disseminating IoT-acquired patient data in a secure way to all relevant healthcare stakeholders [63]. Blockchain can reinforce trust and address problems related to limited access to healthcare [67]. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Search Keywords/Query Phrase** & **Identified Records** &
\begin{tabular}{c} **Selected Items (after** \\ **Removing Duplicates)** \\ \end{tabular} & **Articles References** \\ \hline Blockchain and IoT & 342 & 38 & [13; 14; 15; 17; 18; 19; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44; 45; 46; 47; 48; 49; 50; 51; 52; 53; 54] \\ Blockchain and Ambient Assisted Living & 15 & 5 & [55; 56; 57; 58; 59] \\ Blockchain and Active Assisted Living & 2 & 1 & [60] \\ Blockchain and Ambient Intelligence & 7 & 1 & [61] \\ Blockchain and remote care & 39 & 22 & [62; 63; 64; 65; 66; 67; 68; 69; 70; 71; 72; 73; 74; 75; 76; 77; 78; 79; 80; 81; 82; 83] \\ Blockchain data ownership in healthcare & 15 & 6 & [84; 85; 86; 87; 88; 89] \\ Blockchain data sharing and analytics & 16 & 7 & [10; 16; 90; 91; 92; 93; 94] \\ in healthcare & 55 & 7 & [95; 96; 97; 98; 99; 100; 99; 11] \\ Blockchain and IoT security and privacy & & & [95; 96; 97; 99; 100; 101] \\ in healthcare & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Results overview. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Ambient Assisted** & **Blockchain Usage** & **References** \\
**Living Use Case** & **Reinforce trust, provenance tracking** & [63; 67; 72] \\  & Remote monitoring and telemedicine & [63; 65; 67; 68; 69; 69; 67; 69; 64] \\ IoT-based monitoring & Patient data-efficient dissemination & \\ and intervention & and interoperability & [17; 18; 57; 64; 71; 84] \\  & Personalized care services & [17; 65; 70; 94] \\  & Automation using smart contracts & [17; 28; 66; 75] \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Blockchain usage benefits of IoT monitoring in AAL systems. The integration of IoT with blockchain may contribute to the relief of pressure on sanitary systems while simultaneously providing tailored care services to enhance people's quality of life [65; 94]. The growing geriatric population with chronic medical conditions increased the adoption of IoT devices for remote at-home monitoring [68] and telemedicine [69]. These have become even more evident during the COVID-19 pandemic [63; 67]. An IoT taxonomy relevant for ambient assisted living systems is provided in [16; 47]. Five categories have been identified: sensor-based, resource-based, communication-based, software-based, and security-based methods. Blockchain has promising features for developing data-flow architectures that integrate the monitoring devices and assure patient data-efficient dissemination to relevant healthcare stakeholders [57; 64]. The marriage of blockchain with Internet of Things technology supports the paradigm shift towards preventive and personalized care systems [17; 70]. Although blockchain and IoT adoption in ambient assisted living systems is still in its early stages, it can address flaws in the care processes [18] and close some communication gaps, assuring better interoperability [71; 84]. An investigation into the development of smart ambulances is presented in [19]. The blockchain can be used to increase interoperability and efficiency of information exchanges with the hospital for timely intervention in an emergency department [72]. Blockchain is a good choice for establishing a decentralized, self-contained IoT system deployed in older adults' homes [75].