## 4 Wireless Body Area Networks (WBANs)
### Wearable Wireless Body Area Network (WWBAN)  
WSN technology has the potential to offer a wide range of benefits to patients, medical staff, and society through continuous monitoring in an ambulatory setting, early detection of abnormal conditions, supervised rehabilitation, and potential discovery of knowledge through data mining of all gathered information. This subsection shows how to use the architecture and mechanism of WWBANs as one of the main points of this paper, as well as key infrastructure enabling unobtrusive, continuous, daily monitoring of health. In addition, this subsection describes some important implementation issues. Finally, we give some applications of wearable sensors as in smart shirt (smart life) and biopotential acquisition system application. Wearable health monitoring systems allow the individual to follow closely the changes in her or his vital functions and provide feedback for maintaining optimal health status. If integrated into the telemedicine system, such systems can alert medical personnel when life-threatening changes occur. In addition, patients may benefit from continuous long-term monitoring as a part of a diagnostic procedure. We can achieve optimal maintenance of a chronic condition, or can be monitored in the recovery period after the acute event or surgical procedure. Long-term health monitoring can capture the diurnal and circadian variations in physiological signals. These changes, for example, are a very good indicator of cardiac recovery of patients after myocardial infarction [49]. Long-term monitoring can also confirm adherence to treatment guidelines or help monitor the effects of drug therapy. Other patients may also benefit from these systems; for example, monitors can be used during physical rehabilitation after hip or knee surgeries, stroke rehabilitation, or brain trauma rehabilitation. The use of wearable sensors for monitoring various health-related biometric parameters in everyday activities is attracting more interest recently. Many people are familiar with the use of devices such as wearable heart rate monitors and pedometers for medical reasons or as part of a fitness regime. Interest in the use of such wearable systems for personal health and rehabilitation has increased as part of a wider initiative for increasing the input of the individual or patient in their own care [50]. It is believed that this could help in reducing the strain put on healthcare systems of aging populations, rising costs and increasing incidence of chronic diseases requiring long term care. To date the focus has been on the use of wearable sensors to convert physical biometrics such as heart or respiratory rate into electrical signals. For instance, EU funded projects such as WEALTHY and My Heart use sensorised cotton shirts to measure respiratory activity, electrocardiograms, electromyograms and body posture [51-53]. In addition, NASA [54] is developing a wearable patch to control heart rate, blood pressure and other physiological parameters for astronauts [52]. Other systemsinclude the Lifeshirt, developed by Vivo metrics, the body monitoring system developed by Body Media and the Nike-Apple iPod Sports kit [55]. While the growing success of sensors that monitor the physical properties, relatively little has been done in the field of wearable chemical sensors that can be used for real-time daily monitoring of bodily fluids such as tears, sweat [56], urine and blood. Although some achievements, such as the development of the Glucowatch and other wearable systems for monitoring glucose levels in diabetics, the widespread use of chemical sensors has been complicated by several factors that are difficult to overcome. These include sample collection and delivery, sensor calibration, wearability and security issues [32,55]. WWBANs are a key part of a multi-stages or multi-layered system of telemedicine as shown in Figure 4. The architecture includes the first stage to cover the number of wireless nodes of medical sensor that are integrated into WWBANs.