Detecting and Estimating Magnetic Fluid Properties by a Needle- Type GMR Sensor

Magnetic fluid or magnetic liquid are colloidal solutions of ultra-fine magnetic materials. Ferromagnet-ic materials consist of magnetic or other compound containing iron, nickel or cobalt, by a particle size of 5 to 50 nanometers, generally in a superparamagnetic, ferromagnetic or diamagnetic state. Magnetic fluids have a unique combination of strength and ability to interact with the magnetic field. This paper proposes to estimate and detect magnetic fluid weight density (concentration as low as 1%) by giant magnetore-sistance (GMR) sensor. The high sensitivity of the sensor is around 11 μV/μT. We propose to use it for bio-applications to characterize magnetic microfluides. For this application a Helmholtz coil was simulated and fabricated to make more uniform magnetic flux density. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3496

Sensors Auto-calibration Method - Using Programmable Interface Circuit Front-end

In this paper we present a standard auto-calibration method of sensors. The purpose is to correct the accumulated errors at the sensor output. A universal conditioning circuit is used with the sensor, and the transfer function of the measurement chain is periodically corrected according to the progressive correction method. References physical inputs are used to allow the adjustment of the measurement and to calculate the calibration coefficients. Test results obtained using this method present a considerable enhancement of the measurement accuracy and a good handling of cross-sensitivity problem

Modeling of a Non-invasive Electromagnetic Sensor for the Measurement Glycaemia

In this paper, we present the modeling of a non-invasive electromagnetic sensor for the measurement glycaemia. The model is based on a bio-impedance measurement. First, we optimized the dimensions of the sensor’s parameters that can influence on measurement. Second, we investigated the influence of the dielectric parameters on the conductivity and its impact on the measurement of glycaemia. Results from this study demonstrate that the variation of the sensor impedance depends on the resistance and the inductance, which depend on the conductivity. The sensitivity of the output and input signal ratio strongly depends on the conductivity of the medium under investigation. Maximum conductivity at the resonance frequency was demonstrated

Implants médicaux et champs électromagnétiques basses fréquences 0–100 kHz

Présents dans notre environnement les rayonnements électromagnétiques (EM) suscitent de multiples questions quant à leurs effets potentiels pour les porteurs de dispositifs médicaux actifs implantés (DMAI). Le nombre croissant de porteurs d’implants médicaux, y compris dans la population active, a entraîné un questionnement quant à leur comportement en présence d’un champ EM. L’interaction entre le corps humain et les champs EM reste complexe et dépend de multiples facteurs tels que la fréquence, la puissance et la modulation des champs. Nous présentons ici une revue de cette problématique dans le cas des champs EM basse fréquence