M. Nadi - Academia.edu (original) (raw)

Papers by M. Nadi

Research paper thumbnail of Physical and Electrical Modeling of Interdigitated Electrode Arrays for Bioimpedance Spectroscopy

Lecture Notes in Electrical Engineering, 2011

ABSTRACT This paper concerns a theoretical and electrical modelling of interdigital sensor in a w... more ABSTRACT This paper concerns a theoretical and electrical modelling of interdigital sensor in a wide band frequency. A theoretical approach is proposed to optimize the use of the sensor for bioimpedance spectroscopy. CoventorWare® software was used to modelize in three dimensions the interdigital sensor system for measuring electrical impedance of biological medium. Complete system simulation by Finite element method (FEM) was used for sensor sensitivity optimization. The influence of geometric parameters (number of fingers, width of the electrodes, ...), on the impedance spectroscopy of biological medium was studied. A high level description of the sensor and the biological medium was also developed under VHDL-AMS with SystemVision® software from mentor graphics. The simulation results are compared with measurements obtained with a true interdigitated sensor illustrating a good correlation. This shows that even the theoretical model is simple, it remains very effective.

Research paper thumbnail of Design and Realization of a Planar Interdigital Microsensor for Biological Medium Characterization

Smart Sensors, Measurement and Instrumentation, 2015

Research paper thumbnail of Temperature Measurements Using US Tomography : theoretical Aspects

Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society Volume 13: 1991, 1991

ABSTRACT First Page of the Article

Research paper thumbnail of Hybrid Microfluidic Biosensor for Single Cell Flow Impedance Spectroscopy: Theoretical Approach and First Validations

Research paper thumbnail of Spectroscopic Susceptibility Measurements of Magnetic Markers by SV-GMR Needle Probe

Journal of the Magnetics Society of Japan, 2011

ABSTRACT Journal of the Magnetics Society of Japan 35 (2), 157-162

Research paper thumbnail of A multichannel interstitial capacitive hyperthermia system as an adjunct to brachytherapy

Images of the Twenty-First Century. Proceedings of the Annual International Engineering in Medicine and Biology Society, 1989

An alternative interstitial hyperthermia system using thin flexible electrode wires operating at ... more An alternative interstitial hyperthermia system using thin flexible electrode wires operating at 27.12 MHz has been developed, and an 8-channel apparatus has been evaluated. Its major benefit is its potentializing effect, which is obtained without affecting radiation therapy techniques. It is possible to match the electrode to any kind of catheter implantation used for radiotherapy (even in a loop). Major advantages of this method are radial and longitudinal uniformity of heating, free choice of active length for each electrode, flexibility, and compatibility with the implanted radiotherapy catheters

Research paper thumbnail of Design of an interstitial capacitive hyperthermia system operating at 27.12 MHz

Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 1988

The authors suggest an alternative interstitial method operating at 27.12 MHz. Physically, the sy... more The authors suggest an alternative interstitial method operating at 27.12 MHz. Physically, the system is essentially capacitive and the heating is induced by the conduction current between the 'hot' electrode and the ground plane. Thermographic results obtained with a two-channel homemade apparatus are presented. The simplicity and low cost of the technology, the possibility of tailoring the electrodes to the

Research paper thumbnail of Implantable cardioverter-defibrillators exposed to low frequency magnetic fields

2011 XXXth URSI General Assembly and Scientific Symposium, 2011

This paper presents a numerical modeling study of electromagnetic interference (EMI) in implantab... more This paper presents a numerical modeling study of electromagnetic interference (EMI) in implantable cardioverter-defibrillators (ICDs), exposed to low frequency magnetic fields. Initially, an analysis of the standards that consider interference in ICDs was performed, to determine the level of induced voltage that may occur when the device is exposed to such magnetic fields. A Helmholtz coil was used to generate a uniform magnetic field. The magnetic field exposure was performed for the frontal position (front to back).This position presents the worst case scenario. The induced electric fields and voltage were investigated in both a simple homogenous block (brick) and in an anatomical model (virtual phantom). The ICD's sensitivity parameters were adjusted to minimum values (e.g. 0.2 mV for ventricular detection). This maximum sensitivity corresponds experimentally to the worst-case EMI scenarios. The results showed that magnetic fields above 5000 µT were required for the ICD to possibly present a dysfunction in the homogenous block, while they were only 1400µT in the anatomical model. These results could be informative for any proposed standards concerning the safety of ICDs (CENELEC, INCIRP) for workers as well as for the general public.

Research paper thumbnail of Use Of Calcium Sulfate For Thermoluminescent Thermal Dosimetry

Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 1992

Abstract The authors proposed the use of manganese-doped calcium sulfate irradiated for thermal d... more Abstract The authors proposed the use of manganese-doped calcium sulfate irradiated for thermal dosimetry. This thermoluminescent compound shows a high sensitivity to temperatures ranging between 40 C and 50 C. Calibration procedure and experiments on ...

Research paper thumbnail of Measurement of EM properties in the frequency range 0.4-110 MHz

Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society, 1995

ABSTRACT

Research paper thumbnail of Optimization of planar interdigitated electrode array for bioimpedance spectroscopy restriction of the number of electrodes

2011 Fifth International Conference on Sensing Technology, 2011

This paper concerns physical model of interdigitated sensor in the frequency range 102−107 Hz. A ... more This paper concerns physical model of interdigitated sensor in the frequency range 102−107 Hz. A theoretical approach is proposed to optimize the use of the sensor for bioimpedance spectroscopy. CoventorWare® software was used to modelize in three dimensions the interdigital sensor system for measuring electrical impedance of biological medium. Complete system simulation by Finite element method (FEM) was used for

Research paper thumbnail of Characterization of a needle-type probe GMR sensor for biomedical applications

2013 IEEE SENSORS, 2013

ABSTRACT

Research paper thumbnail of Model of an NMR imaging "bird cage" coil: Enhancing axial homogeneity of the magnetic field

Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 1992

ABSTRACT A bird cage coil was modified in order to increase the longitudinal magnetic field. This... more ABSTRACT A bird cage coil was modified in order to increase the longitudinal magnetic field. This was obtained using a phase difference circuit between the internal wires. model based on the circuit theory. Theoretical results show the advantage of this modified structure.

Research paper thumbnail of Effect Of Temperature Variations On The Dielectric Properties Of A Radiofrequency Gelatin Water Phantom

Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 1992

ABSTRACT Not Available

Research paper thumbnail of Bioimpedance spectroscopy for cell characterization in the 50Hz-5MHz frequency range

2006 Ph.D. Research in Microelectronics and Electronics, 2006

Abstract This paper presents impedance spectroscopy measurements based on auto-balancing bridge m... more Abstract This paper presents impedance spectroscopy measurements based on auto-balancing bridge method (50Hz-5MHz) on a single Xenopeus Oocyte cell with a two electrodes sensor chip. It has been seen that the presence of the cell in the sensor modify ...

Research paper thumbnail of Temperature Measurements Using Ultrasound : Experimental Results

Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 1992

ABSTRACT Different methods for measuring temperature with a non invasive system have been propose... more ABSTRACT Different methods for measuring temperature with a non invasive system have been proposed. We reported experiments on measurement of internal temperature distribution of objects using the velocity of ultrasound. Relation between velocity and temperature is discussed and practical results are presented.

Research paper thumbnail of Hardware and software implementation for an auto-calibrated measurement system

Proceedings of IEEE Sensors 2003 (IEEE Cat. No.03CH37498), 2003

ABSTRACT In this paper we present the mixed hardware and software implementation of an auto-calib... more ABSTRACT In this paper we present the mixed hardware and software implementation of an auto-calibrated measurement system. The use of an analog programmable circuit (FPAA) as a sensor's conditioning interface, allows a full benefit of its reconfigurable aspect, to carry out self-test and self-adjustment routines, in order to calibrate the measurement chain. The proposed software calibration method permits a successive correction and linearization of the whole measurement system transfer function, using a few number of calibration data. The proposed auto-calibration method can be used for different sensors types, and allows considerable cost reduction of their exploitation and calibration.

Research paper thumbnail of Ultrasound thermography: Theoretical aspects and feasibility

Research paper thumbnail of Functions of diffraction correction and analytical solutions in nonlinear acoustic measurement

Arxiv preprint arXiv:0801.0508, 2008

This paper presents an analytical formulation for correcting the diffraction associated to the se... more This paper presents an analytical formulation for correcting the diffraction associated to the second harmonic of an acoustic wave, more compact than that usually used. This new formulation, resulting from an approximation of the correction applied to fundamental, makes it possible to obtain simple solutions for the second harmonic of the average acoustic pressure, but sufficiently precise for measuring the parameter of nonlinearity B/A in a finite amplitude method. Comparison with other expressions requiring numerical integration, show the solutions are precise in the nearfield.

Research paper thumbnail of Dielectric properties of blood: an investigation of haematocrit dependence

Physiological Measurement, 2003

We have investigated the haematocrit dependence of the electrical parameters (relative permittivi... more We have investigated the haematocrit dependence of the electrical parameters (relative permittivity and conductivity) of blood. The measuring set-up, composed of an impedancemeter (HP 4291A), an open-ended coaxial line and a temperature controlling set, was designed for dielectric measurements in the 1 MHz to 1 GHz frequency range. Measurements were performed on ex vivo animal (cow and sheep) blood at 37 • C. The two dielectric parameters appeared to be strongly dependent on the haematocrit. The permittivity versus frequency decreases then increases when the haematocrit decreases. The conductivity increases in the whole frequency range when the haematocrit decreases. Due to the lack of comparative data on the frequency range explored, we compare the dielectric profiles with those deduced from the Maxwell-Fricke theoretical model.

Research paper thumbnail of Physical and Electrical Modeling of Interdigitated Electrode Arrays for Bioimpedance Spectroscopy

Lecture Notes in Electrical Engineering, 2011

ABSTRACT This paper concerns a theoretical and electrical modelling of interdigital sensor in a w... more ABSTRACT This paper concerns a theoretical and electrical modelling of interdigital sensor in a wide band frequency. A theoretical approach is proposed to optimize the use of the sensor for bioimpedance spectroscopy. CoventorWare® software was used to modelize in three dimensions the interdigital sensor system for measuring electrical impedance of biological medium. Complete system simulation by Finite element method (FEM) was used for sensor sensitivity optimization. The influence of geometric parameters (number of fingers, width of the electrodes, ...), on the impedance spectroscopy of biological medium was studied. A high level description of the sensor and the biological medium was also developed under VHDL-AMS with SystemVision® software from mentor graphics. The simulation results are compared with measurements obtained with a true interdigitated sensor illustrating a good correlation. This shows that even the theoretical model is simple, it remains very effective.

Research paper thumbnail of Design and Realization of a Planar Interdigital Microsensor for Biological Medium Characterization

Smart Sensors, Measurement and Instrumentation, 2015

Research paper thumbnail of Temperature Measurements Using US Tomography : theoretical Aspects

Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society Volume 13: 1991, 1991

ABSTRACT First Page of the Article

Research paper thumbnail of Hybrid Microfluidic Biosensor for Single Cell Flow Impedance Spectroscopy: Theoretical Approach and First Validations

Research paper thumbnail of Spectroscopic Susceptibility Measurements of Magnetic Markers by SV-GMR Needle Probe

Journal of the Magnetics Society of Japan, 2011

ABSTRACT Journal of the Magnetics Society of Japan 35 (2), 157-162

Research paper thumbnail of A multichannel interstitial capacitive hyperthermia system as an adjunct to brachytherapy

Images of the Twenty-First Century. Proceedings of the Annual International Engineering in Medicine and Biology Society, 1989

An alternative interstitial hyperthermia system using thin flexible electrode wires operating at ... more An alternative interstitial hyperthermia system using thin flexible electrode wires operating at 27.12 MHz has been developed, and an 8-channel apparatus has been evaluated. Its major benefit is its potentializing effect, which is obtained without affecting radiation therapy techniques. It is possible to match the electrode to any kind of catheter implantation used for radiotherapy (even in a loop). Major advantages of this method are radial and longitudinal uniformity of heating, free choice of active length for each electrode, flexibility, and compatibility with the implanted radiotherapy catheters

Research paper thumbnail of Design of an interstitial capacitive hyperthermia system operating at 27.12 MHz

Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 1988

The authors suggest an alternative interstitial method operating at 27.12 MHz. Physically, the sy... more The authors suggest an alternative interstitial method operating at 27.12 MHz. Physically, the system is essentially capacitive and the heating is induced by the conduction current between the 'hot' electrode and the ground plane. Thermographic results obtained with a two-channel homemade apparatus are presented. The simplicity and low cost of the technology, the possibility of tailoring the electrodes to the

Research paper thumbnail of Implantable cardioverter-defibrillators exposed to low frequency magnetic fields

2011 XXXth URSI General Assembly and Scientific Symposium, 2011

This paper presents a numerical modeling study of electromagnetic interference (EMI) in implantab... more This paper presents a numerical modeling study of electromagnetic interference (EMI) in implantable cardioverter-defibrillators (ICDs), exposed to low frequency magnetic fields. Initially, an analysis of the standards that consider interference in ICDs was performed, to determine the level of induced voltage that may occur when the device is exposed to such magnetic fields. A Helmholtz coil was used to generate a uniform magnetic field. The magnetic field exposure was performed for the frontal position (front to back).This position presents the worst case scenario. The induced electric fields and voltage were investigated in both a simple homogenous block (brick) and in an anatomical model (virtual phantom). The ICD's sensitivity parameters were adjusted to minimum values (e.g. 0.2 mV for ventricular detection). This maximum sensitivity corresponds experimentally to the worst-case EMI scenarios. The results showed that magnetic fields above 5000 µT were required for the ICD to possibly present a dysfunction in the homogenous block, while they were only 1400µT in the anatomical model. These results could be informative for any proposed standards concerning the safety of ICDs (CENELEC, INCIRP) for workers as well as for the general public.

Research paper thumbnail of Use Of Calcium Sulfate For Thermoluminescent Thermal Dosimetry

Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 1992

Abstract The authors proposed the use of manganese-doped calcium sulfate irradiated for thermal d... more Abstract The authors proposed the use of manganese-doped calcium sulfate irradiated for thermal dosimetry. This thermoluminescent compound shows a high sensitivity to temperatures ranging between 40 C and 50 C. Calibration procedure and experiments on ...

Research paper thumbnail of Measurement of EM properties in the frequency range 0.4-110 MHz

Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society, 1995

ABSTRACT

Research paper thumbnail of Optimization of planar interdigitated electrode array for bioimpedance spectroscopy restriction of the number of electrodes

2011 Fifth International Conference on Sensing Technology, 2011

This paper concerns physical model of interdigitated sensor in the frequency range 102−107 Hz. A ... more This paper concerns physical model of interdigitated sensor in the frequency range 102−107 Hz. A theoretical approach is proposed to optimize the use of the sensor for bioimpedance spectroscopy. CoventorWare® software was used to modelize in three dimensions the interdigital sensor system for measuring electrical impedance of biological medium. Complete system simulation by Finite element method (FEM) was used for

Research paper thumbnail of Characterization of a needle-type probe GMR sensor for biomedical applications

2013 IEEE SENSORS, 2013

ABSTRACT

Research paper thumbnail of Model of an NMR imaging "bird cage" coil: Enhancing axial homogeneity of the magnetic field

Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 1992

ABSTRACT A bird cage coil was modified in order to increase the longitudinal magnetic field. This... more ABSTRACT A bird cage coil was modified in order to increase the longitudinal magnetic field. This was obtained using a phase difference circuit between the internal wires. model based on the circuit theory. Theoretical results show the advantage of this modified structure.

Research paper thumbnail of Effect Of Temperature Variations On The Dielectric Properties Of A Radiofrequency Gelatin Water Phantom

Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 1992

ABSTRACT Not Available

Research paper thumbnail of Bioimpedance spectroscopy for cell characterization in the 50Hz-5MHz frequency range

2006 Ph.D. Research in Microelectronics and Electronics, 2006

Abstract This paper presents impedance spectroscopy measurements based on auto-balancing bridge m... more Abstract This paper presents impedance spectroscopy measurements based on auto-balancing bridge method (50Hz-5MHz) on a single Xenopeus Oocyte cell with a two electrodes sensor chip. It has been seen that the presence of the cell in the sensor modify ...

Research paper thumbnail of Temperature Measurements Using Ultrasound : Experimental Results

Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 1992

ABSTRACT Different methods for measuring temperature with a non invasive system have been propose... more ABSTRACT Different methods for measuring temperature with a non invasive system have been proposed. We reported experiments on measurement of internal temperature distribution of objects using the velocity of ultrasound. Relation between velocity and temperature is discussed and practical results are presented.

Research paper thumbnail of Hardware and software implementation for an auto-calibrated measurement system

Proceedings of IEEE Sensors 2003 (IEEE Cat. No.03CH37498), 2003

ABSTRACT In this paper we present the mixed hardware and software implementation of an auto-calib... more ABSTRACT In this paper we present the mixed hardware and software implementation of an auto-calibrated measurement system. The use of an analog programmable circuit (FPAA) as a sensor's conditioning interface, allows a full benefit of its reconfigurable aspect, to carry out self-test and self-adjustment routines, in order to calibrate the measurement chain. The proposed software calibration method permits a successive correction and linearization of the whole measurement system transfer function, using a few number of calibration data. The proposed auto-calibration method can be used for different sensors types, and allows considerable cost reduction of their exploitation and calibration.

Research paper thumbnail of Ultrasound thermography: Theoretical aspects and feasibility

Research paper thumbnail of Functions of diffraction correction and analytical solutions in nonlinear acoustic measurement

Arxiv preprint arXiv:0801.0508, 2008

This paper presents an analytical formulation for correcting the diffraction associated to the se... more This paper presents an analytical formulation for correcting the diffraction associated to the second harmonic of an acoustic wave, more compact than that usually used. This new formulation, resulting from an approximation of the correction applied to fundamental, makes it possible to obtain simple solutions for the second harmonic of the average acoustic pressure, but sufficiently precise for measuring the parameter of nonlinearity B/A in a finite amplitude method. Comparison with other expressions requiring numerical integration, show the solutions are precise in the nearfield.

Research paper thumbnail of Dielectric properties of blood: an investigation of haematocrit dependence

Physiological Measurement, 2003

We have investigated the haematocrit dependence of the electrical parameters (relative permittivi... more We have investigated the haematocrit dependence of the electrical parameters (relative permittivity and conductivity) of blood. The measuring set-up, composed of an impedancemeter (HP 4291A), an open-ended coaxial line and a temperature controlling set, was designed for dielectric measurements in the 1 MHz to 1 GHz frequency range. Measurements were performed on ex vivo animal (cow and sheep) blood at 37 • C. The two dielectric parameters appeared to be strongly dependent on the haematocrit. The permittivity versus frequency decreases then increases when the haematocrit decreases. The conductivity increases in the whole frequency range when the haematocrit decreases. Due to the lack of comparative data on the frequency range explored, we compare the dielectric profiles with those deduced from the Maxwell-Fricke theoretical model.