Papers by Aoday H M Alrawi
IFMBE Proceedings
A new approach is studied to detect the artery stiffness index (ASI) and endothelial dysfunction ... more A new approach is studied to detect the artery stiffness index (ASI) and endothelial dysfunction degree by using the blood volume pulse (BVP) during pulsatile cycle. In this approach, the BVP is measured and Fast Fourier Transform (FFT) is used to analyze the ...
Abstract The current source circuit is one of the most important parts in the bioelectrical imped... more Abstract The current source circuit is one of the most important parts in the bioelectrical impedance devices and Bio Impedance tomography (BIT). There are many types of these circuits like (Howland, one op-amp, two op-amps, etc). In this study three types of ...
Journal of The Electrochemical Society, 2015
Dengue virus infection is a very deadly disease that threatens human lives in subtropical and tro... more Dengue virus infection is a very deadly disease that threatens human lives in subtropical and tropical regions. Thus, for early and reliable diagnosis of Dengue virus infection, a sensitive, specific, and label-free electrochemical immunosensor was developed for the direct detection of the unstructured protein NS1. The NS1 biosensor was designed with a biosensing surface consisting of antifouling moieties and biorecognition molecules to enhance the specificity of the immunosensor for target analyte detection in complicated biological samples such as human sera. The immunosensor exhibited a wide detection range (5-4000 ng mL −1) based on electrochemical impedance spectroscopy (EIS) measurements with a coefficient of determination (R 2) of 0.94, correlation coefficient (R) of 0.95, high reproducibility, and good stability for 21 days at 4 •
AFRICAN JOURNAL OF BIOTECHNOLOGY
Measuring blood hematocrit noninvasively is reviewed in this paper. Although there is an inclinat... more Measuring blood hematocrit noninvasively is reviewed in this paper. Although there is an inclination to measure the hematocrit by determining the bioelectrical impedance of the blood, in vitro experimental methods still remain practically inapplicable. The blood sample size is determined when blood samples are examined. Determining the impedance and volume of blood is the biggest challenge in measuring the hematocrit noninvasively without drawing a blood sample. Calculating the blood impedance in vivo requires developing an impedance measurement using a multi-frequency method and also calculating the change in pressure simultaneously during the heart's pulsatile cycle.
IFMBE Proceedings, 2009
... The aC fixed current circuit with very low current between 500 uamp and 1mamp are normally us... more ... The aC fixed current circuit with very low current between 500 uamp and 1mamp are normally used in the bioelectrical impedance analyses (BIa) and bioelectrical impedance tomography (BIT ... and for a constant Vin , a constant output current is recorded for Rsense constant. ...
Journal of Electrical Bioimpedance, 2013
Alternating current sources are mainly used in bioelectrical impedance devices. Nowadays 50 – 100... more Alternating current sources are mainly used in bioelectrical impedance devices. Nowadays 50 – 100 kHz bioelectrical impedance devices are commonly used for body composition analysis. High frequency bioelectrical impedance analysis devices are mostly used in bioimpedance tomography and blood analysis. High speed op-amps and voltage comparators are used in this circuit. Direct current feedback is used to prevent delay. An N-Channel J-FET transistor was used to establish the voltage controlled gain amplifier (VCG). A sine wave signal has been applied as input voltage. The value of this signal should be constant in 170 mV rms to keep the output current in about 1 mA rms. Four frequencies; 100 kHz, 1 MHz, 2 MHz and 3.2 MHz were applied to the circuit and the current was measured for different load resistances. The results showed that the current was stable for changes in the resistor load, bouncing around an average point as a result of bouncing DC feedback.
4th Kuala Lumpur International Conference on Biomedical Engineering 2008 pp 208-211, 2008
A new approach is studied to detect the artery stiffness index (ASI) and endothelial dysfunction ... more A new approach is studied to detect the artery stiffness index (ASI) and endothelial dysfunction degree by using the blood volume pulse (BVP) during pulsatile cycle. In this approach, the BVP is measured and Fast Fourier Transform (FFT) is used to analyze the plotted signal to its frequency fundamentals. A simple hand made data acquisition system is used to sense the changes in pressure by using the normal Sphygmomanometer device. Six patients are tested, three males and three females. Three of them having hypertension and the rest are healthy control patients. two software programs built using Delphi 2007 language. One to acquire the data from the data acquisition and the second one is to analyze the data. From each patient two waveforms are plotted, the first one after increasing the pressure to 90 mmHg direct, and the second after increasing the pressure above the systolic pressure for 2–3 minutes and then reducing it to 90 mmHg. Analyzing the results shows that there is a major ...
Dengue virus infection is a very deadly disease that threatens human lives in subtropical and tro... more Dengue virus infection is a very deadly disease that threatens human lives in subtropical and tropical regions. Thus, for early and reliable diagnosis of Dengue virus infection, a sensitive, specific, and label-free electrochemical immunosensor was developed for the direct detection of the unstructured protein NS1. The NS1 biosensor was designed with a biosensing surface consisting of antifouling moieties and biorecognition molecules to enhance the specificity of the immunosensor for target analyte detection in complicated biological samples such as human sera. The immunosensor exhibited a wide detection range (5–4000 ng mL −1) based on electrochemical impedance spectroscopy (EIS) measurements with a coefficient of determination (R 2) of 0.94, correlation coefficient (R) of 0.95, high reproducibility, and good stability for 21 days at 4 • C. The developed immunosensor was able to detect the NS1 antigen in actual serum specimens from patients infected with Dengue virus. Moreover, the immunosensor is not only highly selective for the NS1 antigen, but also did not cross-react with human sera infected with malaria parasites.
The current source circuit is one of the most important parts in the bioelectrical impedance devi... more The current source circuit is one of the most important parts in the bioelectrical impedance devices and Bio Impedance tomography (BIT). There are many types of these circuits like (Howland, one op-amp, two op-amps, etc). In this study three types of electronic circuits are built and tested by using "Tina 7" simulation software from Texas Instrument (TI). THS4022 high speed Dual op-amps from Texas Instruments (TI) are used. The results showed that Howland circuit and one op-amp circuit are very stable up to the frequencies of 10 MHz, better than the two op-amp circuit. The two op-amp circuit is good for low frequencies with 10 KHz maximum frequency.
Measuring blood hematocrit noninvasively is reviewed in this paper. Although there is an inclinat... more Measuring blood hematocrit noninvasively is reviewed in this paper. Although there is an inclination to
measure the hematocrit by determining the bioelectrical impedance of the blood, in vitro experimental
methods still remain practically inapplicable. The blood sample size is determined when blood samples
are examined. Determining the impedance and volume of blood is the biggest challenge in measuring
the hematocrit noninvasively without drawing a blood sample. Calculating the blood impedance in vivo
requires developing an impedance measurement using a multi-frequency method and also calculating
the change in pressure simultaneously during the heart’s pulsatile cycle.
Uploads
Papers by Aoday H M Alrawi
measure the hematocrit by determining the bioelectrical impedance of the blood, in vitro experimental
methods still remain practically inapplicable. The blood sample size is determined when blood samples
are examined. Determining the impedance and volume of blood is the biggest challenge in measuring
the hematocrit noninvasively without drawing a blood sample. Calculating the blood impedance in vivo
requires developing an impedance measurement using a multi-frequency method and also calculating
the change in pressure simultaneously during the heart’s pulsatile cycle.
measure the hematocrit by determining the bioelectrical impedance of the blood, in vitro experimental
methods still remain practically inapplicable. The blood sample size is determined when blood samples
are examined. Determining the impedance and volume of blood is the biggest challenge in measuring
the hematocrit noninvasively without drawing a blood sample. Calculating the blood impedance in vivo
requires developing an impedance measurement using a multi-frequency method and also calculating
the change in pressure simultaneously during the heart’s pulsatile cycle.