## 3 Wireless Body Area Network (WBAN)
### Wireless Communication Technologies  
With the recent evolution of wireless technology, several wireless communication technologies have been introduced to wireless medical sensors used in Healthcare 4.0 and IoMT. These heterogeneous interfaces are commonly used to enable connectivity and data exchange. The key wireless technologies deployed in medical IoT applications are introduced as follows [71; 72; 73; 74]. * Bluetooth: Bluetooth technology is widely adopted for connecting medical devices and wearables to smartphones, tablets, and other computing devices. It allows for the transmission of health data, remote device control, and seamless integration with mobile health applications. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Category** & **Available Market** & **Features and Technical Specification** \\ \hline \multirow{5}{*}{\begin{tabular}{c} Pulse Sensor \\ [66] \\ \end{tabular} } & \(\bullet\) & It operates at a voltage of +5 V /+3.3 V. \\  & \(\bullet\) & Light source: super red LEDs at 660 nm. \\  & \(\bullet\) & This sensor measures the heart rate and biometric pulse rate. \\  & \(\bullet\) & It deploys a noise cancellation circuit. \\  & \(\bullet\) & It deploys a plug-and-play model. \\  & \(\bullet\) & It uses integral amplifiers. \\  & \(\bullet\) & 100 mA is the maximum current. \\  & \(\bullet\) & VCC is +5 v DC. \\  & \(\bullet\) & 4 mA is the current consumption. \\ \hline \multirow{5}{*}{\begin{tabular}{c} AD8232 ECG Sensor \\ [67] \\ \end{tabular} } & \(\bullet\) & It uses a three-pole low pass filter (LPF) with adjustable gain. \\  & \(\bullet\) & The operating range of the supply is 2 to 3.5 V. \\  & \(\bullet\) & Right leg drive (RLD) amplifier included. \\  & \(\bullet\) & It enables high signal gain by utilizing DC blocking. \\  & \(\bullet\) & It uses a two-pole versatility high pass filter (HPF). \\  & \(\bullet\) & Only lead ECG is incorporated into the front end as a whole. \\  & \(\bullet\) & There are 2 or 3 electrode combinations. \\ \hline \multirow{5}{*}{\begin{tabular}{c} Heart rate sensor IR \\ [68] \\ \end{tabular} } & \(\bullet\) & The pulse monitor operates as follows: the phototransistor is on the opposite side of the finger from the LED, which is turned on one side of the finger. \\  & \(\bullet\) & It deploys a Ky-039 heartbeat sensing module. This heartbeat detection module detects the pulse of the finger using a strong infrared (IR) lead and a phototransistor, a red LED flashes with each pulse. \\  & \(\bullet\) & To detect pulsation in fingers, it uses an optical transistor and an IR LED. \\  & \(\bullet\) & When blood flows through the finger, the phototransistor’s resistance will change somewhat, allowing for the collection of the flux emitted. \\ \hline \multirow{5}{*}{\
\begin{tabular}{c} EEG \\ \end{tabular} } & \(\bullet\) & It measures blood glucose in mg/dL. \\  & [69] & \(\bullet\) & It has an integrated LED display. \\  & \(\bullet\) & It deploys a Bluetooth interface. \\  & \(\bullet\) & It achieves an accuracy of 99\%. \\  & \(\bullet\) & It uses a 3 V battery. \\ \hline \multirow{5}{*}{
\begin{tabular}{c} EEG/EEG Monitoring \\ [70] \\ \end{tabular} } & \(\bullet\) & It enables real-time tracking. \\  & \(\bullet\) & It deploys AI to assist signal analysis. \\  & \(\bullet\) & Detect many heart abnormalities, including atrial flutter and fibrillation. \\  & \(\bullet\) & It is a lightweight rechargeable device, which facilitates individual use. \\  & \(\bullet\) & It supports various operating systems. \\  & \(\bullet\) & Power source: 3.7 V DC. \\  & \(\bullet\) & It achieves a maximum error of \(\pm\)10\%. \\ \hline \hline \end{tabular}
\end{table} 
Table 4: _Cont._Bluetooth Low Energy (BLE): It is a wireless communication technology designed to provide short-range, low-power connectivity between devices. BLE is a subset of the Bluetooth technology standard and is optimized for applications that require low power consumption and periodic data exchanges.