# Validation of Wired and Wireless Interconnected Body Sensor Networks
## 2 BSN System Design
### DigiAID--A Wired BSN  
Inspired by first aid box, our innovation is to build a set of new digital first aid tools using BSNs for health monitoring using reasonable cost sensors (Electrocardiogram (ECG), Phonocardiogram, Esophagogastroduodenoscopy, pressure, pulse, temperature and oximeter etc.).  
DigiAID [4] is a tool that we proposed to bring rapid assistance to individuals in emergency cases. The rapidity is ensured through an early diagnosis and assessment of the health condition without an expert in loop. All what we require is a BSN that can measure important health indications in real-time and then be able to judge on the criticality of an individual. Through this platform, we continuously monitor three elementary critical vital signs, that is, RR, HR and MS. For the implementation of DigiAID, we selected the eHealth Sensor Shield [34]. Being open-source hardware/software and low-cost, the platform promises a faster acceptance and spread of our implementation, as well as large-scale trials in daily life activities. There are primarily three sensors attached to the DigiAID, that is, airflow sensor, pulse oximeter and position sensor. The airflow sensor is used to check RR of the patient. The pulse oximeter is a noninvasive method of indicating the arterial oxygen saturation of functional hemoglobin. It is very useful in any setting where the patient's oxygenation is unstable. Alongside it also provides RR of the patient. The position sensor consists of three axis accelerometer to record the body position of the patient such as standing, sitting, supine, prone, left and right. These sensors are used to help an individual as well as on-site paramedic staff and remote doctors in understanding the patient health metrics and classifying the patients that have serious illness. The useful metrics are displayed on the display along with Global Positioning System (GPS) coordinates for patient location. DigiAID has a keypad interface for the patient to type and show his consciousness, that is, MS regarding the sensory perception. The value to be inputted by the patient is displayed on the screen. We primarily plan to use a microphone along with a 3D accelerometer to detect the MS of the patient. However, the automation of the MS capture is an ongoing step. It should be noted that DigiAID can be easily used to monitor health parameters during routine activities and is not restricted only to emergency situations. The complete hardware solution is shown in Figure 2.  
Several experimental BSN platforms exist such as References [35; 36; 37]. Only a subset of them enable biometric and medical applications [38; 39; 40; 41; 42]. The core functionality provided by these platforms is to monitor the human body in real time by capturing some of its key health state indicators and to collect sensitive data for subsequent analysis and medical diagnosis.  
Several academic platforms such as References [39; 40; 43], MobiHealth [44; 45], MYOTEL [42], Personal Health Monitor (PHM) [41; 46] have been developed and applied in various clinical settings. However, these platforms are still unavailable commercially and therefore cannot be used to compare with DigiAID. On the other hand, more and more commercial platforms are being released. Examples include the Shimmer Health BSN [38; 47] from Intel, the Simband health sensor platform [48] from Samsung and biometric smart shirt by Hexoskin [5]. From above systems we have chosen Hexoskin because its system design is very close to DigiAID and can be easily compared due to its portability and providing similar health indicators.