Signal Conditioning provided by Sensitive Elements of Electric Bioimpedance Sensors

2021 ◽  
Vol 69 (1) ◽  
pp. 51-58
Author(s):  
Lucian PÎSLARU-DĂNESCU ◽  
Victor STOICA ◽  
Gabriela TELIPAN
Keyword(s):  
Amplification Factor ◽  
Conductive Polymer ◽  
Instrumentation Amplifier ◽  
Signal Conditioning ◽  
Differential Mode ◽  
Electrical Measurements ◽  
Useful Signal ◽  
External Resistor ◽  
Electronic Instrumentation ◽  
Electrocardiogram Monitoring

Dry polarizable electric bioimpedance sensors for ECG (electrocardiogram) monitoring requires the use of signal conditioning electronic circuits that take over alternating ΔU voltages with a frequency of 40 kHz and peak-to-peak amplitude in the range of 10-50 mV. The sensitive elements of these sensors are made of sensitive materials like as conductive polymer polypyrrole or hybrid nanocomposite with 10 and 20% Ag incorporated in the polypyrrole polymer. The useful signal is picked up in differential mode by an instrumentation amplifier. The gain of the instrumentation amplifier is set to A = 100 by connecting a single external resistor, RG. The problem of eliminating the mass loops and obtaining a common mode signal is solved by using an amplifier with galvanic isolation, with the amplification factor A = 1, supplied with double differential voltage. To reject any parasitic signals that may accompany the useful signal, an electronic bandpass filtering module is used. Electrical measurements were performed which showed the accuracy of the signal amplified by the electronic instrumentation amplifier module used in the "differential mode" connection.

Characterization of Circuit Blocks for Configurable Analog-Front-End

2014 ◽  
Vol 2014 (HITEC) ◽  
pp. 000146-000153 ◽  
Author(s):  
Bruce W. Ohme ◽  
Mark R. Larson ◽  
Bhal Tulpule ◽  
Alireza Behbahani
Keyword(s):  
Embedded Systems ◽  
Integrated Circuit ◽  
Extreme Temperature ◽  
Silicon On Insulator ◽  
Instrumentation Amplifier ◽  
Signal Conditioning ◽  
Wafer Level ◽  
Voltage Range ◽  
Front End ◽  
Programmable Gain

Analog functions have been implemented in a Silicon-on-Insulator (SOI) process optimized for high-temperature (>225°C) operation. These include a linear regulator/reference block that supports input voltages up to 50V and provides multiple independent voltage outputs. Additional blocks provide configurable sensor excitation levels of up to 10V DC and/or 20V AC-differential, with current limiting and monitoring. A dual-channel Programmable-Gain-Instrumentation Amplifier (PGIA) and a high-level AC input block with programmable gain and offset serve signal conditioning, gain, and scaling needs. A multiplexer and analog buffer provide an output that is scaled and centered for down-stream A-to-D conversion. Limited component availability and high component counts deter development of sensing and control electronics for extreme temperature (>200°) applications. Systems require front-end power conditioning, sensor excitation and monitoring, response amplification, scaling, and multiplexing. Back-end Analog-to-Digital conversion and digital processing/control can be implemented using one or two integrated circuit chips, whereas the front-end functions require component counts in the dozens. The low level of integration in the available portfolio of SOI devices results in high component count when constructing signal conditioning interfaces for aerospace sensors. These include quasi-DC sensors such as thermo-couples, strain-gauges, bridge transducers as well as AC-coupled sensors and position transducers, such as Linear Variable Differential Transducers (LVDT's). Furthermore, a majority of sensor applications are best served by excitation/response voltage ranges that typically exceed the voltage range of digital electronics (either 5V or 3.3V in currently available digital IC's for use above 200°C). These constraints led Embedded Systems LLC to design a generic device which was implemented by Honeywell as an analog ASIC (Application Specific Integrated Circuit). This paper will describe the ASIC block-level capabilities in the context of the typical applications and present characterization data from wafer-level testing at the target temperature range (225C). This material is based upon work performed by Honeywell International under a subcontract from Embedded Systems LLC, funding for which was provided by the U.S. Air Force Small Business Innovative Research program.

AN ULTRA-LOW-POWER CURRENT-MODE INTEGRATED CMOS INSTRUMENTATION AMPLIFIER FOR PERSONAL ECG RECORDERS

2008 ◽  
Vol 17 (06) ◽  
pp. 1053-1067 ◽  
Author(s):  
MARYAM SHOJAEI BAGHINI ◽  
SUDIP NAG ◽  
RAKESH K. LAL ◽  
DINESH K. SHARMA
Keyword(s):  
Low Power ◽  
Design Methodology ◽  
Current Mode ◽  
Corner Frequency ◽  
Noise Voltage ◽  
Instrumentation Amplifier ◽  
Ecg Signal ◽  
Signal Conditioning ◽  
Ultra Low Power ◽  
Measurement Results

This paper presents an ultra-low-power current-mode ECG instrumentation amplifier, which is designed based on the current balancing technique and fabricated in TSMC 0.35 μm CMOS process. The instrumentation amplifier, which is presented here has three features. First, the instrumentation amplifier is a full-CMOS implementation of current-balancing technique applied for ECG signal conditioning. Second, the instrumentation amplifier is of ultra-low-power due to a power-oriented design methodology, which makes its power consumption very low compared to the earlier reported works for ECG recording applications. Third, integrated programmable bandpass filtering is implemented in the amplifier itself, which provides a compact solution for analog ECG signal conditioning. Measurement results show that the amplifier only draws 9 μA current from a 3.3 V lithium-ion battery, while CMRR of 100 dB and input voltage dynamic range of ± 6 mV are achieved. By considering trade-offs between input noise voltage and power, noise performance was compromised with power and area for ultra-low-power ECG signal conditioning applications. Measurement results show [Formula: see text] input referred noise voltage with a flicker noise corner frequency of 15 Hz at 9 μA dc current and small area, which is appropriate for the desired application. Measurement results meet the recommended specifications for signal conditioning of portable ECG monitoring devices. Design methodology, fabrication considerations, measurement setup, and experimental results are also explained in this paper.

Non-Contact Electrodes

10.12737/7283 ◽  
2014 ◽  
Vol 21 (4) ◽  
pp. 121-124
Author(s):  
Тараканов ◽  
S. Tarakanov ◽  
Подольский ◽  
M. Podolskiy ◽  
Кузнецов ◽  
...  
Keyword(s):  
Optimal Solution ◽  
Fundamental Principle ◽  
The Public ◽  
Long Period ◽  
Public Market ◽  
Useful Signal ◽  
Electrocardiogram Monitoring ◽  
Contact Sensors ◽  
Contact Electrodes

This paper reviews current approaches to the registration of the electrocardiogram for a long period. A review of existing solutions based on contact adhesive and fabric electrodes and non-contact ones is carried out. The last type of electrodes is offered as an optimal solution. The fundamental principle of operation of the new electrodes is fixing the capacitance parameters, in contrast to the classical voltage registration. The ability to operate through a tissue, thereby providing a suitable level of comfort for long-term utilizing of these electrodes is advantage in comparison with the contact adhesive and the contact dry textiles ones for electrocardiogram monitoring. The main problem is that all types of the electrodes are affected with noise spoiling useful signal when the person moves. To minimize the influence of artifacts, some developers of registration systems for measuring electrical activity of heart and brain have chosen the way of manufacturing high-cost microchips, what can be an obstacle for non-contact sensors penetrating of the public market. The authors propose an approach to solving the difficulties in signal recordings in indirect way without using of specialized microchip. The results of their own research are presented.

Adhesive Conductive Polymer for Wearable Electrocardiogram Monitoring

2017 ◽  
Author(s):  
D. Yamamoto ◽  
Y. Yamamoto ◽  
M. Takada ◽  
H. Naito ◽  
T. Arie ◽  
...  
Keyword(s):  
Conductive Polymer ◽  
Electrocardiogram Monitoring

A 2.6 GΩ, 1.4 μVrms current-reuse instrumentation amplifier for wearable electrocardiogram monitoring

2021 ◽  
Vol 107 ◽  
pp. 104940
Author(s):  
Wenfei Cao ◽  
Yi Liu ◽  
Shubin Liu ◽  
Ling Wang ◽  
Rui Ma ◽  
...  
Keyword(s):  
Instrumentation Amplifier ◽  
Current Reuse ◽  
Electrocardiogram Monitoring

A New Transresistance-Mode Instrumentation Amplifier with Low Number of MOS Transistors and Electronic Tuning Opportunity

2016 ◽  
Vol 25 (04) ◽  
pp. 1650022 ◽  
Author(s):  
Leila Safari ◽  
Erkan Yuce ◽  
Shahram Minaei
Keyword(s):  
Simple Structure ◽  
Time Domain Analysis ◽  
Instrumentation Amplifier ◽  
Mos Transistors ◽  
Differential Mode ◽  
Robust Performance ◽  
Chip Area ◽  
Input And Output ◽  
Maximum Value ◽  
Electronic Tuning

In this paper, the simplest possible electronically adjustable transresistance-mode (TRM) instrumentation amplifier (IA) using only eight MOS transistors is presented. Extremely simple structure of the proposed IA leads to a wide bandwidth and robust performance against mismatches and parasitic capacitances. Of more interest is that the differential-mode gain of the proposed IA can be electronically varied by control voltages. Post-layout and pre-layout simulation results based on 0.18[Formula: see text][Formula: see text]m TSMC CMOS parameters are included to confirm the validity of the theoretical analysis. Despite extremely simple structure, its input and output impedances are 1.93 and 1.68[Formula: see text]k[Formula: see text], respectively. Time domain analysis shows that for an input signal of 20[Formula: see text][Formula: see text]A peak to peak, maximum value of THD is 4.5% for different frequencies. Monte Carlo simulation is also carried out, which proves robust performance of the proposed IA against mismatches. The required chip area is only [Formula: see text].

Evaluation of thin film Capacitors Fabricated from Heterogeneous Polypyrrole Based Langmuir-Blodgett Films

1989 ◽  
Vol 173 ◽  
Author(s):  
R. B. Rosner ◽  
M.F. Rubner
Keyword(s):  
Thin Film ◽  
Dielectric Constant ◽  
Conductive Polymer ◽  
Molecular Architecture ◽  
Electrical Measurements ◽  
Langmuir Blodgett ◽  
Thin Film Capacitors ◽  
Langmuir Blodgett Films ◽  
Transverse Conductivity ◽  
Conducting Polypyrrole

ABSTRACTThe electrical properties of Langmuir-Blodgett films of conducting polypyrrole were investigated in an effort to illucidate the molecular architecture of these multilayer films and determine the mechanism of conduction. Values of the dielectric constant and transverse conductivity recorded as a function of frequency were determined from electrical measurements performed on devices made with the conductive polymer. The highly anisotropic nature of the conductivity as well as the frequency dependence demonstrated by both the conductivity and dielectric constant provide evidence for a highly ordered molecular structure in which the conductive and insulative components of the multilayer film form an organized, layered structure. Even greater control of the electrical and structural properties has been achieved through the fabrication of a thin film superlattice in which the conducting polymer and an insulating derivative were deposited as alternating bilayers. The properties of the superlattice were close to those predicted for an inhomogeneous, mixed media.

A Signal Conditioning Preposing Circuit for Portable Wheel Load Measure Plate

2013 ◽  
Vol 274 ◽  
pp. 95-98
Author(s):  
Xin Tong Zhao ◽  
Xiao Dong Lu ◽  
Wen Sheng Lu ◽  
Cheng Jun Jin ◽  
Xi Jun Zhang ◽  
...  
Keyword(s):  
Thermal Noise ◽  
Force Sensor ◽  
High Gain ◽  
Low Noise ◽  
Instrumentation Amplifier ◽  
Signal Conditioning ◽  
Practical Application ◽  
Wheel Load ◽  
Strain Measure ◽  
High Cmrr

Portable wheel loads measure plate is force sensor based on strain measure and it can bear multidimensional force simultaneously. It is able to recognize radial wheel load through decoupling. Signal conditioning of the sensor will affect the measure accuracy. There are many strain-gauges in the plate. So the signal of measure plate will include CM noise, thermal noise and high shift. The signal conditioning aimed at these disadvantages should be high gain, high accuracy, low noise, low shift, high CMRR. Multisim is adopted to analyze the signal conditioning including strain measure amplifying circuit, instrumentation amplifier AD620, operational amplifier OP07. It is turned out to be low linear distortion and is able to satisfy practical application through the experiment.

CBED study of low-temperature InP grown by gas source MBE

1993 ◽  
Vol 51 ◽  
pp. 810-811
Author(s):  
R. Rajesh ◽  
M.J. Kim ◽  
J.S. Bow ◽  
R.W. Carpenter ◽  
G.N. Maracas
Keyword(s):  
Low Temperature ◽  
Second Phase ◽  
Material System ◽  
Ion Milling ◽  
Electrical Measurements ◽  
Gas Source ◽  
Structural And Electrical Properties ◽  
The One ◽  
Lt Inp ◽  
Gas Source Mbe

In our previous work on MBE grown low temperature (LT) InP, attempts had been made to understand the relationships between the structural and electrical properties of this material system. Electrical measurements had established an enhancement of the resistivity of the phosphorus-rich LT InP layers with annealing under a P2 flux, which was directly correlated with the presence of second-phase particles. Further investigations, however, have revealed the presence of two fundamentally different types of precipitates. The first type are the surface particles, essentially an artefact of argon ion milling and containing mostly pure indium. The second type and the one more important to the study are the dense precipitates in the bulk of the annealed layers. These are phosphorus-rich and are believed to contribute to the improvement in the resistivity of the material.The observation of metallic indium islands solely in the annealed LT layers warranted further study in order to better understand the exact reasons for their formation.

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