A Design Based on Bioimpedance Spectroscopy Method in Human Abdominal Adipose Measurement System

2012 ◽  
Vol 263-266 ◽  
pp. 241-245 ◽  
Author(s):  
Zhang Yong Li ◽  
Fei Ba Chang ◽  
Xiao Bo Chen ◽  
Rui Leng ◽  
Wei Wang
Keyword(s):  
Measurement System ◽  
Current Source ◽  
Impedance Measurement ◽  
Bioelectrical Impedance ◽  
Abdominal Fat ◽  
Signal Generator ◽  
Constant Current ◽  
Phase Detection ◽  
Bioimpedance Spectroscopy ◽  
Constant Current Source

This article describes a measurement of human abdominal fat device designed based on BIS (bioimpedance spectroscopy), the device adopts four electrodes multi-frequency bioelectrical impedance measurement system, including the programmable signal generator module and the amplitude and phase detection module. Program controlled signal generator module can generate the high output impedance of the constant current source in the eight frequency points constant current source between 5KHz and1MHz; amplitude phase detecting module can detect the human body electrical impedance real part and imaginary part information. Therefore, the device can be accurate measurement of human abdominal impedance information in the whole frequency range. Meanwhile, according to the selected electrode fixed position and the appropriate measurement scheme, can calculate the corresponding depth of abdominal fat content.

scholarly journals Design of a Microcontroller Based System to Implement 4-Electode Focused Impedance Method (FIM)

2013 ◽  
Vol 4 (1) ◽  
pp. 75-79
Author(s):  
Dr Aktharuzzaman ◽  
Tanvir N Baig ◽  
K Siddique-e Rabbani
Keyword(s):  
Measurement System ◽  
Medical Physics ◽  
Impedance Measurement ◽  
Simulation Software ◽  
Signal Generator ◽  
Constant Current ◽  
Impedance Method ◽  
Electronic Circuitry ◽  
Measuring Unit

Designing of electronic circuitry and development of necessary software has been performed in the present work for a microcontroller based 4-electrode Focused Impedance measurement system. This needs a complex sequential analog switching of constant current ac signal generator and a potential measuring unit to 4 electrodes on the object under study. The performances of the designed system and the developed microcontroller software have been studied using a commercially available simulation software, ‘Proteus-7’, and the results are very satisfactory. DOI: http://dx.doi.org/10.3329/bjmp.v4i1.14690 Bangladesh Journal of Medical Physics Vol.4 No.1 2011 75-79

The Design of High-Precision Temperature Measurement System Based on C8051F350 and PT100

2013 ◽  
Vol 423-426 ◽  
pp. 2559-2562 ◽  
Author(s):  
Long Liu ◽  
Yun Cui Zhang ◽  
Shen Hua ◽  
Jun Xiao ◽  
Li Jia Huang
Keyword(s):  
Temperature Measurement ◽  
High Precision ◽  
Measurement System ◽  
Current Source ◽  
Constant Current ◽  
Constant Current Source ◽  
Interface Circuit ◽  
Software Algorithms ◽  
Precision Temperature ◽  
Temperature Measurement System

This article describes the design of High-Precision Temperature Measurement System based on C8051F350 and PT100. The system consists of the control circuit, temperature sensors, signal amplification circuit, field bus interface circuit. The system adopts constant current source method and a differential measurement circuit. A 24-bit A/D built in the CPU is used to sample the data and Non-linear compensation by software algorithms for it. The design improves the accuracy of the temperature measurement system.

Coordinate Measurement System for Copper-Clad Plate

2015 ◽  
Vol 734 ◽  
pp. 75-78
Author(s):  
Li Juan Hou ◽  
Fu Xin Mao
Keyword(s):  
Measurement System ◽  
Current Source ◽  
Linearization Method ◽  
Constant Current ◽  
Constant Current Source ◽  
Coordinate Measurement ◽  
Fitting Method ◽  
Signal Amplifier ◽  
Curve Fitting Method ◽  
Switch Circuit

For getting the coordinate of contactor on CCL, the measurement system transformed resistance into voltage by providing constant current on CCL. The system includes MCU, 3A constant current source, MOSFET switch circuit, signal amplifier circuit and A/D converter. By the curve-fitting method, the equipotent lines of CCL were simulated with MATLAB according to the discrete data. The equations of equipotent lines were obtained with second-order polynomial fitting method. The two curves which the contactor located in were acquired with local linearization method, and the coordinate was gained by calculating solving equation groups.

scholarly journals Performances of Multi-Frequency Voltage to Current Converters for Bioimpedance Spectroscopy

2013 ◽  
Vol 5 (1) ◽  
pp. 71-76 ◽  
Author(s):  
Shekh Md Mahmudul Islam ◽  
Mohammad Anisur Rahman Reza ◽  
Md Adnan Kiber
Keyword(s):  
Breast Cancer ◽  
Impedance Spectroscopy ◽  
Human Body ◽  
Tissue Characterization ◽  
Medical Physics ◽  
Current Source ◽  
Impedance Measurement ◽  
Current Amplitude ◽  
Constant Current ◽  
Bioimpedance Spectroscopy

Breast cancer is one of the most common diseases affecting women and the mortality rate is very high in Bangladesh, mainly due to the lack of early diagnosis. X-ray mammography is not available widely in Bangladesh, besides it has an associated biological hazard. Multi-frequency bio-impedance measurement or bio-impedance spectroscopy has a great potential in many biomedical applications including breast cancer screening which involves tissue characterization. In Bio-impedance spectroscopy a range of frequencies of low level current is injected to the human body and corresponding bio-impedance is measured. In a typical bio-impedance measurement system an ac source with a constant current amplitude is an essential part in which the current amplitude should not change with frequency or load, the latter being typically of the order of a few kilo ohms in the human body. The constant current source is usually obtained from a voltage-to-current converter and several standard designs are available, for example a floating current source, a Howland current source and an enhanced Howland current source. The present work was taken up to perform a comparative study of these three types of current sources based on a commonly available low cost operational amplifier, 741. It was found that the enhanced Howland current source gave the best performance, the current being almost constant up to a frequency of about 10kHz for a load of 10k?. This work gives an understanding of this fundamental circuit segment that is essential for the development of a Bioimpedance Spectroscopy system. DOI: http://dx.doi.org/10.3329/bjmp.v5i1.14671 Bangladesh Journal of Medical Physics Vol.5 No.1 2012 71-76

A Method to Improve the Stability of Constant Current Source

2020 ◽  
Author(s):  
Sang Shangming ◽  
Feng Rongwei ◽  
Chen Hongliang ◽  
Wu Nan
Keyword(s):  
Current Source ◽  
Constant Current ◽  
Constant Current Source ◽  
The Stability

scholarly journals Low noise constant current source for bias dependent noise measurements

2011 ◽  
Vol 82 (1) ◽  
pp. 013906 ◽  
Author(s):  
D. Talukdar ◽  
R. K. Chakraborty ◽  
Suvendu Bose ◽  
K. K. Bardhan
Keyword(s):  
Current Source ◽  
Low Noise ◽  
Constant Current ◽  
Constant Current Source ◽  
Noise Measurements

A three-phase constant-current source using an immittance converter

2005 ◽  
Vol 151 (4) ◽  
pp. 47-54 ◽  
Author(s):  
Hisaichi Irie ◽  
Shunsuke Oohashi
Keyword(s):  
Current Source ◽  
Constant Current ◽  
Constant Current Source ◽  
Three Phase ◽  
Immittance Converter ◽  
Phase Constant

The Method of Conductor Resistance Autocompensation in New Two-Wire Thermistor Temperature Measurement

2013 ◽  
Vol 718-720 ◽  
pp. 450-454
Author(s):  
Ning Yang ◽  
Hai Ting Zhu ◽  
Shao Shan Zhong
Keyword(s):  
Temperature Measurement ◽  
Current Source ◽  
Processing System ◽  
Constant Current ◽  
Large Temperature ◽  
Constant Current Source ◽  
Thermistor Temperature ◽  
Important Position ◽  
Temperature Measurement System ◽  
Data Acquisition And Processing

Thermistor has a large temperature range, good stability and resistance to oxidation, which occupies an important position in the low-temperature measurement. This article describes new two-wire thermistor temperature measurement device using the Freescale MC9S12XS128 MCU with sampling capacitance. The device is composed of the MCU with its own A/D, MC9S12XS128 MCU, sampling capacitance, amplifier, boosted circuit, data acquisition and processing system, constant current source, etc. Using constant current source and 16-bit A/D converter designs the temperature measurement circuit, it can eliminate the effect from the conductor resistances in the traditional two-wire resistance temperature measurement system and reduce the measurement error which conductor resistances bring. The method is simple, practical, with high accuracy, strong anti-interference ability and other characteristics.

Research and Analysis of a Portable Precision Temperature Sensor

2014 ◽  
Vol 945-949 ◽  
pp. 1924-1931
Author(s):  
Hai Qing Yao ◽  
Heng Cao ◽  
Fei Jiang ◽  
Bo Sun
Keyword(s):  
Temperature Sensor ◽  
Low Cost ◽  
Current Source ◽  
Control Unit ◽  
Constant Current ◽  
Interference Signal ◽  
Constant Current Source ◽  
Differential Signal ◽  
Precision Temperature ◽  
Micro Control Unit

Based on the excellent performance of Pt100, a portable low-cost precision temperature sensor has been designed, whose core chips are REF03, AD8603, AD7788 and precision resistors. Constant current source (CCS) for 4-wire Pt100 is constituted by REF03, AD8603 and precision resistors. AD7788 measures the differential signal on Pt100 and suppresses the common mode interference signal. Analysis software running on the micro control unit (MCU) filters the digital code from AD7788, and then calculates the current temperature value according to the resistance-temperature mathematical model of Pt100. Analysis and experimental results show that the temperature measurement accuracy of the sensor can reach ±1°C within the range of 0°C-650°C.

Sign in / Sign up

Export Citation Format

Share Document