**2. Wearable technologies and devices**

Wearable systems and devices will be in the next following years, an important part of individuals' daily lives. Wearable healthcare systems may measure and record several medical parameters such as heartbeat rate, blood pressure, sweat rate, arterial blood pressure, body temperature, electrocardiograms, and electro-dermal activity. Wearable devices may provide monitoring and scanning features that are not provided by cellular phones and other computing devices. Wireless devices and technologies are employed to analyze and process the data collected by the healthcare devices. The collected medical information may be transmitted to the healthcare center to analyze the collected medical information. This process may send a message to the physician to call the patient that needs immediate medical treatment.

#### **2.1 Features of wearable healthcare and sport devices**


*Green Wearable Sensors for Medical, Energy Harvesting, Communication, and IoT Systems DOI: http://dx.doi.org/10.5772/intechopen.112352*

• Healthcare wearable systems and devices may help to solve Obesity problems, Sleep disorders, and cardiovascular diseases.

Wearable healthcare systems may measure and record several medical parameters such as heartbeat rate, blood pressure, sweat rate, arterial blood pressure, body temperature, electrocardiograms, and electro-dermal activity. The application of WBANs in medical centers with energy harvesting units, where the medical parameters of a large number of patients are constantly being monitored, is presented in **Figure 1**.

#### **2.2 IoT systems**

IoT devices are wireless communication modules of interrelated computing systems, mechanical machines, personal devices, healthcare sensors, and digital machines that possess unique identifiers (UIDs). IoT devices and systems consist of wireless communication modules, processors, sensors, and radiating elements. IoT devices and systems transmit, receive, and process data from networks connected to the Internet web. IoT devices and systems are connected to an IoT gateway network where they gather data that is analyzed online or sent to information centers to be processed and shared with specific IoT modules and devices. The polarization of the receiving channel of IoT and medical devices should match the polarization of the transmitting channel. In several communication devices, the polarization is not defined. In these cases, the receiving antenna should be dual-polarized. IoT systems

#### **Figure 1.**

*Green wireless body area network, WWBAN, health monitoring sensors and system with energy harvesting units.*

are significant in daily work and treatment in healthcare centers. IoT modules and systems may connect several healthcare devices and healthcare information centers to improve healthcare treatment. Efficient medical and IoT systems result in low-cost healthcare treatment.


A block diagram of IoT medical device is presented in **Figure 2**.
