Energy efficient routing for critical physiological parameters in wireless body area networks under mobile emergency scenarios

Abstract

In recent innovations, mobility networks have achieved a promising critical solution to smart healthcare monitoring systems. Focusing on different realistic scenarios, the mobility model with an energy-efficient communication model helps to find the position and efficient path to communicate with biosensors placed on the patients' body. The sensor data applies a prioritized mechanism to broadcast emergency data towards a sink with lesser propagation delays and path loss. Thus, the routing protocol solution integrates the concepts of critical, priority and hierarchical routing techniques for successful transmission of a patient's vital data to the destination. However, the proposed algorithm outperforms existing direct, in-direct and forwarder-based routing techniques concerning lifetime, average remaining energy and packets received or dropped in the network.

Introduction

The e-healthcare technology involves using wearable sensors to monitor the health condition of a patient's bio-signals whereby novel techniques applications miniaturize these sensors. The technology has some advantages in remote monitoring such as physical condition and wellness monitoring, wellbeing monitoring, home treatment and timely discovery of disease disorders. A Wireless Body Area Network (WBAN) is a combination of biosensors placed in-vivo or in-vitro of the patient's body and controlled by a central coordinator unit. It forms a communication network that focuses on transmitting human body's internal vital data such as Blood Pressure (BP), Body Temperature (BT), Respiration Rate (RR), Blood Glucose Level (BSL), Electro-Cardio-Gram (ECG), Electro-Myo-Gram (EMG), Electro-Encephalo-Gram (EEG), Electro-Occulo-Gram (EOG) [1] and an external parameter; humidity to the base station.

The internet connects wearable sensors to Personal Digital Assistance (PDA), which advances pervasive computing to enhance communication. This device has more processing power, battery and data storage capacity that is rechargeable using an external source. During the design of this technology [2], we should not only aim at the device's compact size but also consider the ease of using technology without affecting the patient's health. In indoor or outdoor condition, a few levels of patient monitoring services are necessary, as various patients require several monitoring facilities, e.g., a patient in the emergency unit needs high-organized intermittent information services with less postponement and high throughput than the patient in a typical ward does. Hence, vital signs come first [3] for the patient who has undergone surgery and resting at a home environment compared to specialized signals. Signals prioritize monitored sensor information to provide medical services based on the patient's health status.

Mobility models [4] have the significant impact on the accuracy of simulation results during data communication. Models are necessary to study the behavior of mobile nodes in reality by considering different standard human patterns of mobility such as sitting, standing, sleeping, walking, running, etc. The application scenario selects the best corresponding mobility model whereby a variation in distances between nodes and sinks affects energy resources and packet distribution. A mobility model describes the change in the position of nodes and is mainly due to their directions, movement speed, etc. A corresponding model that depicts its character simulates the positive movement of nodes in real life.

In this work, we proposed Mobility supported Priority -based Energy-Efficient Routing Protocol for Critical Data Transmission (M-PEERPCDT) in WBANs. During static condition (sitting, standing, and sleeping), nodes are in their permanent positions and data is forwarded to the nearest neighbor with lesser efforts. As the person moves from static to a free position (walking and running), nodes placed on the body start changing their position from an initial status. Finding a neighbor under this condition is a difficult task and thus identifying an efficient path for data transmission is energy consuming.

In order to overcome these drawbacks and to perform comparisons with more realistic scenarios, we proposed an energy efficient Predecessor-Successor-Node (PSN) routing technique that utilizes a random walk mobility model and uses a Communication cost (Cc) function metric to find out the changes in the distance between the nodes and the sink at network level. During data processing at the sensor level, forwarding only critical and emergency data by using a threshold-based approach causes a reduction in energy consumption, where the priorities for the sensors depends on the condition of a patient. We implemented the existing mobility model with some modification along with novel routing technique and compared it with the current direct, multi-hop and forwarder node routing techniques followed in Mobility-supporting Adaptive Threshold-based Thermal-aware Energy-efficient Multi-hop Protocol (M-ATTEMPT) [5] and Stable Increased-Throughput Multi-hop Protocol for Link Efficiency (SIMPLE) [6] routing protocol. The remaining sections of the paper include most relevant and recent works in Section 2. Section 3 contains the explanation to the proposed system model and communication routing protocol. The next part is Section 4, which follows a detailed account of the different performance metrics with the analysis and results in Section 5. Lastly, Section 6 includes a proposal for future works related to this study.