-
[show abstract]
[hide abstract]
ABSTRACT: A new challenge in the biomedical engineering is the remote patient monitoring by web applications. This paper proposes a first instance of diagnosis that guide the patients to a first medical point, with the advantage of a flexible structure, suitable for the next web developers, like students from bioinformatics universities. These kinds of applications stand for a sub-component of the telemedicine, as web-assisted medical E-healthcare diagnosis points. A diseases-symptoms database was uploaded in order to establish a final diagnosis. The main scope of this article is to offer a web protocol for medical diagnosis, under educational projects, as application to learning, bioinformatics and telemedicine. The paper presents an original software developed in HTML and its subsidiaries, as a flexible student environment.
Data Compression, Communications and Processing (CCP), 2011 First International Conference on; 07/2011
-
[show abstract]
[hide abstract]
ABSTRACT: The paper presents a hardware solution of the in vivo electrophysiological signals processing, using a continuous data acquisition on PC. The originality of the paper comes from some blocks proposal, which selective amplify the bio signals. One of the major problems in the electrophysiological signals monitoring is the impossibility to record the weak signals from deep organs that are covered by noise or by strong cardiac or muscular signals. An automatic gain control block is used, so that the high power skin signals are less amplified than the low components. The analog processing block is based on a dynamic range compressor, containing the automatic gain control block. The following block is a clipper since to capture all the transitions that escape from the dynamic range compressor. At clipper output a low-pass filter is connected since to abruptly cut the high frequencies, like 50Hz, ECG. The data vector recording is performing by strong internal resources micro controller including ten bits A/D conversion port.
Data Compression, Communications and Processing (CCP), 2011 First International Conference on; 07/2011
-
[show abstract]
[hide abstract]
ABSTRACT: This paper presents the enhanced performances of a glucose biosensor constructed with a dielectric multi-layer Si/SiO2/Si3N4/Al2O3. If the Si/SiO2 system is present in all the silicon integrated sensors, the biosensors processing involves special attention to the intermediate
layer responsible for the biological receptors entrapping. A first experience imposes to use the Si3N4 layer over the SiO2 layer mainly to stops the Na+ and K+ ions diffusion from bio-environment toward the silicon transducer. These results are
reflected in the CV traced curve and a minimum leakage current. The nitride besides to a nanometric top Al2O3 layer grown by anodization, helps to a better enzyme entrapping, maintains the GOD active centers and are in agreement with
the planar technology requirements. An original Al2O3 deposition technique is presented. The final multilayer structure was characterized as a capacitor by CV-metry, ellipsometry,
impedancemetry.
Keywordsbiosensor-deposition-anodization-nanopores
12/2009: pages 459-462;
-
[show abstract]
[hide abstract]
ABSTRACT: The paper presents the aspects of design and implementation of a chain for electrophysiological signal recording, respectively
collection, analog processing and digital data recording. The analog processing is based of dynamic range compressor circuit
composed by the automatic gain control with a recovery delay to minimize the distortions, thermal behavior compensation and
an adaptation stage for levelmeter. At compressor output was added a clipper, which must catch all the transitions, that escapes
out of the dynamic range compressor and at clipper output a lowpass filter to cuts abruptly the high frequencies. The data
vector recording is performing by strong internal resources microcontroller including ten bits A/D conversion port.
Keywordsbioelectronics-analog processing-digital recording
12/2009: pages 132-135;
-
[show abstract]
[hide abstract]
ABSTRACT: This paper presents the simulations results and preliminary experiments of a glucose BioFET constructed with a dielectric multi-layer Si/SiO<sub>2</sub>/Si<sub>3</sub>N<sub>4</sub>/Al<sub>2</sub>O<sub>3</sub>. Beside to the Si/SiO<sub>2</sub> system, the biosensors processing involves special attention to the intermediate layer responsible for the biological receptors entrapping. A first experience imposes to use the Si<sub>3</sub>N<sub>4</sub> layer over the SiO<sub>2</sub> layer mainly to stops the Na<sup>+</sup> and K<sup>+</sup> ions diffusion from the bioenvironment toward the silicon transducer. The nitride beside to a porous top Al<sub>2</sub>O<sub>3</sub> layer grown by anodization, helps to a better enzyme entrapping, maintains the GOD active centres and are in agreement with the planar technology requirements. An original Al<sub>2</sub>O<sub>3</sub> deposition technique is presented. The final multilayer structure was characterized as a capacitor using a CV-meter and an ellipsometer.
Semiconductor Conference, 2009. CAS 2009. International; 11/2009
-
[show abstract]
[hide abstract]
ABSTRACT: The modern medicine cannot be conceived without the latest news in engineering technology. One of the challenges is related to the novel energy source inside the human body that can be useful for implantable devices, as pacemakers or in vivo insulin micropumps or biosensors. In this paper, the biofuel properties of the glucose that is regulated within the endocrine pancreas, is analyzed in order to offer alternative methods to biogenerators, using the inside glucose from the bloodstream itself. The glucose concentration is regulated by the beta cells activity, via the insulin hormone released in the bloodstream. The insulin exocytose in 7 steps is modeled as a digital system, expressed in an organigram, proving the cellular self-organizing. The exocytose phenomenon is accompanied by electrical behavior at membranar level. The entire electrophysiological model of the beta cell is analyzed in order to offer a useful model for diagnosis in medicine, using the inside glucose from the bloodstream.
Clean Electrical Power, 2009 International Conference on; 07/2009
-
[show abstract]
[hide abstract]
ABSTRACT: One of the challenges in the biomedical engineering domain is the Telemedicine. The remote diagnosis, automate instruments for drug delivery or mobile platforms for domestic applications are common targets accepted by the medical insurance companies form the world wide. The Telemedicine need the development of various tools for home analysis, in order to send all the collected analysis to a medical center or to a database on Internet. In this paper is proposed a simple and cheap platform for the Electro-cardio-gram recording on the Personal Computer. The platform consists in a hardware part and a software part. The general electrical circuit for the ECG recording was adapted in order to be available at home applications. The amplified signal is then connected via the microphone muff to PC. A dedicated software converts the input ldquonoiserdquo signal into an ECG trace. In this way, the ECG becomes available, in the simpler mode directly on the computer screen, without any expensive tracer.
Semiconductor Conference, 2008. CAS 2008. International; 11/2008
-
[show abstract]
[hide abstract]
ABSTRACT: The electrical properties of the chemical mediators at synapses level could be investigated in vitro, with some test biodevices. One of neurotransmitters, like epinephrine, placed on an insulator support and contacted with metal electrodes, provides a Biomaterials On Insulators - BOI-type, structure. The test device is inspired from the pseudo-MOS technique, frequently used in the Silicon On Insulator characterisation. The DC regime study allows some polarography experiments. A behavior like the Field Effect Transistor was also investigated in DC regime, biasing a third terminal - the gate. A gate voltage control on the current is expected. It is still linear, emphasising none inversion layer onset. The AC regime measurements of the BOI device provided some conductometry results, providing the epinphrine resistivity.
Semiconductor Conference, 2008. CAS 2008. International; 11/2008
-
[show abstract]
[hide abstract]
ABSTRACT: The Silicon On Insulator technology has reached a new stage through the nanodevices way: Silicon On Nothing, where "Nothing" means a vacuum cavity underneath an ultrathin Si film. A mobile and thin semiconductor membrane results, by enlarging the cavity. In the empty space can be handled a bioliquid using a diffuser/nozzle micropump. The mobile Si membrane is bending by the substrate biasing and plays a double role: as actuator and detector. This paper presents a MEMS, based on a new work principle than traditional ISFETs, which detects the ionic analytes from a bioliquid and has its own actuator for the microfluidic handle.
Semiconductor Conference, 2005. CAS 2005 Proceedings. 2005 International; 11/2005
-
C. Ravariu
[show abstract]
[hide abstract]
ABSTRACT: The SOI technologies become attractive in the nanodevices domain. The study is starting from a SOI nanotransistor with prominent Si-n source and drain regions and thinner p-type layer. The p-film was thinned from 10 nm up to 0.3 nm. This paper presents the last stage: the p-film is completely eliminated. Hence a nothing on insulator configuration results. Essentially, a new nanotransistor, with a vacuum cavity on insulator, placed between two SOI regions representing the source and drain, was proposed.
Semiconductor Conference, 2005. CAS 2005 Proceedings. 2005 International; 11/2005
-
[show abstract]
[hide abstract]
ABSTRACT: The nanotechnology trend needs more precisely models for active devices. From this point of view the design of linear analog circuits lacks models for state-of-the-art MOS transistors to accurately describe the conductance and distortion effects. This is mainly due to inaccurate modelling of the second order effects induced by high vertical gate field such as mobility degradation and short channel series resistance and second order effects induced by parallel drain field like velocity saturation in the ohmic region and channel length modulation in the saturation region. After a rigorous description of transistor conductance in ohmic and saturation region we included these effects in the MOS transistor model, using a compact expression of drain current for computation reasons. The simulations using the new drain current expression were in good agreement with experimental data.
Semiconductor Conference, 2005. CAS 2005 Proceedings. 2005 International; 11/2005
-
[show abstract]
[hide abstract]
ABSTRACT: In the power devices domain, one of the key problem is the edge termination improving. This work proposes an optimisation of the structures with field electrode and SIPOS layer (semi-insulating polycrystalline silicon) in order to accomplish a maximum of the breakdown voltage with a smallest area consumed. For these kinds of structures physical models and some simulations regarding the dynamic behaviour are presented.
Semiconductor Conference, 2004. CAS 2004 Proceedings. 2004 International; 11/2004
-
[show abstract]
[hide abstract]
ABSTRACT: This paper proposes another destination for a biodevice. Frequently, the polarografy and amperometry methods are used to detect the analytes concentrations in biosensors. The purpose of the present device is to characterise the electrical properties of one of the most important neurohormone from the human body: epinephrine. Some experimental curves provide information about the non-linear electrical conduction through this neurotransmitter solution.
Semiconductor Conference, 2004. CAS 2004 Proceedings. 2004 International; 11/2004
-
[show abstract]
[hide abstract]
ABSTRACT: In the last years, biomedical applications of micro and nanotechnologies have been focused toward multifunctional devices. This paper describes the technological process controlled by the simulation of mechanical behaviour for microporous silicon membrane. These semipermeable structures belong to a complex biodevice used in vitro for cell-based assays and in vivo for immunoisolation and drug delivery application.
Semiconductor Conference, 2004. CAS 2004 Proceedings. 2004 International; 11/2004
-
[show abstract]
[hide abstract]
ABSTRACT: The pseudo-MOS transistor is a dedicated device for in situ electrical characterization of the SOI wafers. In this paper were extracted some parameters for a 200nm Si-film manufactured in SIMOX technique. In this scope, experimental Curves I<sub>D</sub>-V<sub>G</sub>, I<sub>D</sub>-V<sub>D</sub> in inversion and accumulation were used, This work presents an alternative method for the threshold and fiat-band voltages extraction, using the Non-linear Electrical Conduction Theorem.
Microelectronics, 2004. 24th International Conference on; 06/2004
-
[show abstract]
[hide abstract]
ABSTRACT: This paper presents the model for an electromechanical variable capacitor designed as an MOS capacitor with a beam. It studies the influences of the beam on the electrical characteristics of the capacitor.
Microelectronics, 2002. MIEL 2002. 23rd International Conference on; 02/2002
-
[show abstract]
[hide abstract]
ABSTRACT: Recently, pressure sensors that combine SOI structures with the properties of piezoelectric layers have been developed. With a SOI-MOSFET used as a transducer element, the sensor can detect pressures just over a threshold value, corresponding to the inversion onset. In this paper, a pseudo-MOS/SOI transistor is the transducer that enhances the work regime: accumulation or inversion for a SOI-MOSFET like regime and depletion for a J-FET like regime. A PZT layer is used for sensing the pressure. New analytical models for the sensor sensitivity in various regimes are presented. ATLAS simulations, based on the concept of "equivalent gate voltage", verify how does the sensor works and provide the current through the transducer. A strongly non-linear characteristic of the sensor results.
Electronics, Circuits and Systems, 2002. 9th International Conference on; 02/2002
-
[show abstract]
[hide abstract]
ABSTRACT: The pseudo-MOS/SOI transistor can be a test device or an inherent part of an SOI device controlled by the back gate. Previous models relied on the depletion approximation to compute the potential and electric field distributions. The advantage is computational simplicity; but it can only be applied just for the depletion regime. The exact solutions of the Poisson equations describe the electric field and potential in the pseudo-MOS transistors for all working regimes. The analytical models are compared with ATLAS simulations.
Semiconductor Conference, 2002. CAS 2002 Proceedings. International; 02/2002
-
[show abstract]
[hide abstract]
ABSTRACT: Blood pressure detection requires both sound detection and pressure measurements. Piezoelectric materials fulfill both aims. Starting from a previous work, a pressure sensor based on a SOI transistor with a piezoelectric layer, was adapted for the blood pressure domain. The ANSYS simulations provide the mechanical stress in the structure. The ATLAS software simulates the electrical behavior. This paper offers a modeling of the sensor and consequently design guidelines.
Semiconductor Conference, 2002. CAS 2002 Proceedings. International; 02/2002
-
[show abstract]
[hide abstract]
ABSTRACT: In the pressure sensors domain, the SOI structures bring some
advantages: electrical insulation, high temperature sensors, an
excellent etch stop layer (buried oxide), compatibility with
microelectronic technology, lowering in thermal noise. The goal of this
paper is to highlight a pressure sensor based on a coupling between
piezoelectric effect in PZT and an Ψ-MOSFET. The analytical models,
that will be presented, stand for a useful tool at a first iteration of
the sensor designing
Semiconductor Conference, 2001. CAS 2001 Proceedings. International; 11/2001
