**1. Introduction**

Wireless Body Area Network is a part of Wireless sensor network (WSN). Wireless body area network contributes a wide range in health monitoring and broadened its applications considerably [1]. Many lives have been passed down through centuries, due to lack of physical evidence and analyzing the patient up to a tolerance value. WBANs are becoming the limelight in the medical field, expanding their applications in a real-time world by collecting the vitals through implanted sensor nodes. A standard for WBAN as IEEE 802.15.6 is formulated by the IEEE fraternity. This had triggered many types of research to study its uses in WBANs [2].

A tremendous increase in recent technology in the subject of sensing, processing has fueled interest in the technology-based health care system. This is an added advantage to assist an elderly patient [3]. Sensor nodes in WBANs are mounted on the surface or inside the patient skin. These nodes are tiny, light-weighted with the required power and energy. The role of these sensor nodes is to transmit the data from source to destination through the skin as a medium. A loss in the medium occurs where signals or data are absorbed by neighboring tissues, which causes a surge in the temperature of the tissue. Likely, this might cause tissue damage. This is an emerging problem throughout the world, causing the patient to endanger tissue or organ with unbearable pain.

WBAN is lauded for its function through sensor nodes and core nodes, known as HUB which acts as a switchyard between sensor nodes and the gateway. HUB is a fixed sensor node that cannot be varied according to IEEE 802.15.6. The sharing of continuous data through HUB involves higher transmission rates. In contrast, SAR, battery level, Priority of the sensor node, and Signal to Inference Ratio (SINR) are compared to other sensor nodes for better transmission [4].

In this chapter, a HUB is selected dynamically in software based on the selection process through the fuzzy decision systems as shown in **Figure 1**. The fuzzy system converts the numeric value into crisp data where the fuzzy logic is applied and calculates the output based on fuzzy rules. It compares the input data with the standard parametric values of SAR, Battery level, Priority, and SINR (Signal to Inference Ratio). The front panel in LabVIEW is used to collect the data and the processing of fuzzy comparison is done in a block diagram, where every step of data is easy to monitor. The system considers the estimated parameters for different sensor nodes by comparing and gives an estimated sensor node as a HUB.

The effect of changing the HUB dynamically is analytically carried out on a testbed using the microcontroller(ESP-32) which is a 32-bit microcontroller with 34 general purpose IO's, 10 touches sensing IO's, DAC, ADC, pulse counter, UART, I 2 C interface, Wi-Fi and Bluetooth as inbuilt application functions, that are mainly used for sending the data(vitals collected) to patients or doctors or neighbors. The sensors used in this testbed are based on application-specific(i.e., in our chapter, we used LM35 for temperature, BMP180 for Blood Pressure measurement, Heartbeat sensor monitoring with finger probe).

The remainder of the work is organized as follows: a description of the relevant work carried out in a focused area is described in the second section. Section 3, gives a glance view of the proposed technique in experimental way and analysis is done. Selection 4, illustrates a detailed overview of the prototype developed,

**Figure 1.** *Fuzzy logic for dynamic HUB selection.*

presenting the obtained simulation results and discussion in Section 5. The last section,6, gives a conclusion about the chapter.
