Ultra Low-Power Sensor Node for Wireless Health Monitoring System

Abstract

Ultra low power sensor node for wireless health monitoring system was designed and implemented in 0.18-µm CMOS. The sensor node functions as an interface circuit to both sensor and RF transceiver. The sensor node consists of an amplifier, an ADC (analog-to-digital converter) as well as digital system. The digital system is embedded with DSP (digital signal processing) for heart rate processing and RF interface for transceiver. The sensor node draws a total current of 7.5-µA from a 0.9-V single supply. The decoding scheme in the RF transceiver can tolerate up to ±22% clock frequency variation.

A Survey on Instrumentation Amplifiers used for Biomedical application

“…16 instrumentation amplifiers have been used to build the acquisition system with an overall CMRR of 100dB. Such a high CMRR along with low power and low noise is possible due to the usage of current feedback amplifier [5].…”

“…The depicted amplifier consists of theDc offset rejection ratio, the input stage and the output stage. Continuous-time asymmetrical differential input structure with DC offset rejection circuit [16] has been used to minimize the input offset. This amplifier provides an open loop voltage gain of 60dB with a CMRR > 85dB.…”

Effect of Decentralized Clustering Algorithm and Hamming Coding on WSN Lifetime and Throughput

“…The binary operation is defined as the exclusive-or of two bits and the energy per binary operation is www.intechopen.com the energy consumed in processing of a two-input Exclusive-Or (XOR) gate. It is assumed in this work that the design of the XOR gate is based on static CMOS which is commonly used in sensor networks (Teo et al, 2007, Enz et al, 2004). The energy per binary operation (E oper ) depends on the fabrication technology (Hempstead et al, 2006, Ragini et al, 2009).…”

“…Wireless Sensor Networks (WSN) has become an interesting field of research because of its wide range of applications such as environmental monitoring, electromagnetic pollution monitoring, medical applications and industrial applications (Teo et al, 2007;Margi et al, 2009;Castelluccia et al, 2005;AbouElSeoud et al, 2010;Tavares et al, 2008). WSN consists of multi-functioning sensor nodes with limited power capacity, so prolonging the lifetime is essential and is one of the main concerns (Castelluccia et al, 2005;Schmidt et al, 2009;Karlsson et al, 2005).…”

Low-power electronics for energy harvesting sensors

“…Energy harvesting has been recently demonstrated for various wireless sensor applications, ranging from sensors for health monitoring of patients [1][2][3], civil engineering structures [4], aircraft structural monitoring [5], sensors in hazardous environments [6], sensors for covert operations, etc. Typical requirements for such sensors and sensor networks are small size, low maintenance, low available power levels, unknown exact location, and/or maintenance difficulties [7].…”