Indoor Air Quality Monitoring Systems for Enhanced Living Environments: A Review toward Sustainable Smart Cities

1. Introduction

The concept of Internet of Things can be better defined as the ubiquitous presence of cyber-physical systems with advanced communication and sensing capabilities [1]. Ambient-Assisted Living is known as a multidisciplinary field that helps to enhance the overall quality of life for individuals, especially for older adults. This field is closely associated with the ecosystem of new-age technologies that promote personal healthcare monitoring with ubiquitous computing [2,3]. Enhanced Living Environments is another relevant term that is also related to the Ambient-Assisted Living area. The idea is supported by Information and Communications Technologies [4]. In general, Enhanced Living Environments include all the Information and Communications Technologies-based achievements to improve the field of Ambient-Assisted Living [5]. Enhanced Living Environments focus on numerous Information and Communications Technologies-powered solutions designed with unique algorithms, systems, and platforms [6]. These innovative applications and flexible services ensure an independent, reliable, and autonomous living [7]. Furthermore, Enhanced Living Environments make use of advancements in the field of the Internet of Things to present Information and Communications Technologies-based solutions for enhanced health and overall well-being [8]. A healthcare system has two main components: Hardware and software. They work together to provide numbers of healthcare applications and services to individuals for promoting overall health and well-being in a pervasive manner [9,10]. Enhanced Living Environments and Ambient-Assisted Living are two significant technologies contributing to the development of advanced healthcare systems [11,12]. Ambient-Assisted Living offers vast potential to address several healthcare challenges when powered with Information and Communications Technologies [13,14]. On the other hand, Enhanced Living Environments make use of medical sensors, wireless communication technologies, microcontrollers, and open-source software platforms for data analytics and visualization in advanced healthcare systems. Ambient Assisted Living technology promise ambient intelligence for Enhanced Living Environments-based healthcare systems. It enables 24/7 monitoring and enhanced control of the environment [15,16]. These advanced healthcare systems provide direct or indirect assistance for maintaining patient health within home environments without moving them to institutionalized environments [17]. Moreover, these systems promise independent movements to the patients while facilitating quality treatments [18]. The new-age healthcare systems incorporate advanced technologies to monitor human health, physiological status, and various environmental parameters. The real-time updates for such measurements are possible with wireless communication technologies such as Wi-Fi, Ethernet, Bluetooth, 3G,...