## 2 Internet of Things for Healthcare
### Wearables  
Wearable sensors are used on a large scale for healthcare systems, such as diagnostic procedures and visualization software, to measure and define living environments and real-time personal activity [3]. Wearables have a remarkable diversity of applications in healthcare, such as real-time monitoring of pediatric patients with cardio-metabolic problems [71], headband for electroencephalogram (EEG) feeling recognition aiming to estimate the life quality of individuals [72], and to detect situations of behavioral anomaly in smart AAL through the collection of movement data combined with the local context [73]. Wearable technologies can be used to reduce the costs of personalized healthcare by providing patient monitoring in their own homes [74]. Wearables are also used for blood pressure monitoring, ring-type heart rate monitoring, and Bluetooth-based electrocardiogram (ECG) monitoring. A tele-home medical solution that incorporates wearables, wireless technologies, and sensor data fusion techniques was presented by [75]. Healthcare systems can be very important to provide ubiquitous healthcare services because they allow continuous access to patient information [76]. Healthcare systems for symbiotic and bio-inspired architectures may enhance the health circumstances and living expectation of an enormous number of individuals [77]. A wearable pervasive medical supervising solution that utilizes unified ECG, accelerometer, and oxygen (SpO2) sensors that provide biological records to be communicated in wireless sensor network using IEEE 802.15.4 to a PC where the data can be displayed and stored was presented by [78]. Non-invasive sensors incorporated in wristbands are used to measure and supervise several biological parameters, such as ECG, EEG, electrodermal (EDA), breathing, and biochemical procedures [79]. These wearable sensors can offer cost-effective answers for remote supervision of ageing individuals at domestic or nursing homes but also increase patient monitoring and care [80]. Wearable computing devices with an embedded camera can determine the user position and orientation by using visual odometry and SLAM (simultaneous localization and mapping) techniques to design assisted living systems capable of offering such guidance with on-site augmented reality, without introducing changes in the environment and using off-the-shelf equipment [81].  
A system that aims to provide an active and healthy routine for individuals and to advise them with recommendations and important life behavior information that incorporates wearable bio-signals sensors and artificial intelligence algorithms was presented by [82]. HealthMon is a mobile healthcare framework towards access that proposes an affordable, retail wristband for clinical monitoring of scenarios, e.g., dementia, Parkinson's, or ageing, and it is used to provide health monitoring and contextualized alerts in real-time, as presented by [83]. Wearable sensors are used to predict and monitor patients by combining clinical observations, resulting in identification of \"abnormal\" biological information resulting from patient deterioration [84]. Wearable sensors are used for monitoring academic, sleep, and mental behavior using mobile phones with classification accuracies ranging from 67% to 92% [85] (Figure 4).  
Figure 4: Mobile sensors.