Design and Optimization of a Low Power Pressure Sensor for Wireless Biomedical Applications

Abstract

A blood pressure sensor suitable for wireless biomedical applications is designed and optimized. State-of-the-art blood pressure sensors based on piezoresistive transducers in a full Wheatstone bridge configuration use low ohmic values because of relatively high sensitivity and low noise approach resulting in high power consumption. In this paper, the piezoresistance values are increased in order to reduce by one order of magnitude the power consumption in comparison with literature approaches. The microelectromechanical system (MEMS) pressure sensor, the mixed signal circuits signal conditioning circuitry, and the successive approximation register (SAR) analog-to-digital converter (ADC) are designed, optimized, and integrated in the same substrate using a commercial 1 μm CMOS technology. As result of the optimization, we obtained a digital sensor with high sensitivity, low noise (0.002 μV/Hz), and low power consumption (358 μW). Finally, the piezoresistance noise does not affect the pressure sensor application since its value is lower than half least significant bit (LSB) of the ADC.

Flexible ferroelectric wearable devices for medical applications

“…When a pressure is applied to a piezoresistive sensing material, its resistance changes in response to that stimuli. This category of active sensing materials is also promising for health monitoring and attached on skin applications due to their ease of manufacturing, low energy consumption ( Sosa et al., 2015 ) (typically current consumption between 1 mA and 50 mA) and their broad range of pressure detection ( Chen et al., 2019 ) (e.g. 259.32 1/kPa in the range of 0 - 2.5 kPa).…”

Performance Investigation of Carbon Nanotube Based Temperature Compensated Piezoresistive Pressure Sensor

“…With the applied pressure , the sensor's diaphragm will deform which induce bending of stresses in the piezoresistors and translate into a fluctuation in the resistance because of the piezoresistive effect [15].Piezoresistive MEMS pressure sensors suffered from a major problem of implicit decline sensitivity to temperature. Piezoresistors in the form of wheatstone bridge configution were placed to convert applied pressure into electrical signal as showen in figure 1.…”

Modeling, Characterization and linearization of Negative Temperature Coefficient (NTC) Thermistor and Pressure Sensors

“…x y (8) Now with these proposed techniques, the temperature and pressure are acquired and the results are presented in section 4. The experimental model was designed and developed to validate the proposed techniques.…”

“…The method was tested for the range of temperature between 3000°K to 3720°K. A full Wheatstone bridge with differential amplifier has been presented [8] to measure the low pressure for wireless biomedical applications. The paper presents the analysis of low magnitude signal conditioning and how the noise affects the pressure measurements if improper ADC selected for the purpose of pressure measurement.…”