## 5 Discussion and Future Directions  
IoT must be assumed as an important and feasible architecture for enhanced healthcare systems. However, several challenges still exist, and research efforts should be made to address usability and user interface; ubiquitous design and ergonomics; data access and data structure; social and ethical issues; and security, privacy, and QoS for enhanced pervasive and personalized healthcare systems. Currently, IoT is responsible for an enormous quantity of personal data that is transferred across the Internet without the guarantee of data privacy. Therefore, several ethical and social questions can be raised about transparency at the expense of our privacy. This is an important challenge to be analyzed particularly on healthcare systems in order to provide protection against observation from non-authorized sources [133]. Pervasive monitoring deals with ultra-sensible data about patient well-being and daily routine, therefore the healthcare systems should incorporate strong security methods to guarantee the reliability of the data. Important legislation and regulations should be made in order to guarantee the user's rights, particularly in the development of healthcare systems. The design of the referred systems should consider ethics as a major factor by adopting policies to ensure that different developers use safe and trustable infrastructures [134]. The healthcare systems data should be protected and implemented in encryption schemes, key management, appropriate cryptographic, and security measures to avoid privacy leakages. Moreover, IoT devices in the healthcare context must be regularly verified to not expose vulnerabilities to security attacks [135]. The proliferation of healthcare services has led to an increase in the amount of data generated, which causes design issues on data access and data structure. Therefore, an extra effort must be made to address the complexity and diversity of the data generated by healthcare systems. Furthermore, the diversity of data sources requires a uniform standard of heterogeneous data management; the diversity of data content requires a unified programming interface for multiple data analysis modules, and the diversity of service objects require a uniform standard service platform interface as was proposed by [136]. The QoS also play a major role in healthcare systems. Efficient and effective cooperation between the physical and digital domains must be guaranteed in order to provide reliable healthcare systems. The state-of-the art technologies, such as 5G, offer several opportunities for the IoT, in general, and to healthcare systems, in particular, especially in real-time applications that involve video on demand [137]. The main application of the enhanced healthcare systems is to develop intelligent and ubiquitous systems for several purposes, such as patient health and well-being monitoring, activity and emotion recognition, anomaly detection in daily routine behavior, and specific diseases supervision for ELEs and to improve occupational health. Additionally, these systems aim to be used on a large scale, which leads to a proliferation of application domains, including the development of platforms on healthcare data sharing, visualization, and analytics. The development of enhanced healthcare sensors is closely related to the design and configuration setting of several sensing technologies for efficient and effective data acquisition. Particularly, wearable sensors, such as EGG, ECG, accelerometers, and heart rate sensors, are a common trend in the design of enhanced healthcare systems. These sensors are commonly positioned on the wrist, belt, hand, and/or chest in order to provide ubiquitous sensing. Mobile devices, such as smartphones, tablets, and smartwatches, are simultaneously used for data collection using built-in sensors, such as GPS, camera, and microphone, but also as a bridge to interface external medical devices. Moreover, the mobile devices have also been used as processing units to transform the collected data into knowledge.