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Microtechnologies in Medicine and Biology, 1st Annual International, Conference On. 2000

Date 12-14 Oct. 2000

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Displaying Results 1 - 25 of 137
  • 1st Annual International IEEE-EMBS Special Topic Conference on Microtechnologies in Medicine and Biology. Proceedings (Cat. No.00EX451)

    Publication Year: 2000
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    Freely Available from IEEE
  • Author index

    Publication Year: 2000 , Page(s): 0_2 - 0_3
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    Freely Available from IEEE
  • Thin- and thick-film structures for miniature biomedical sensors

    Publication Year: 2000 , Page(s): 211 - 215
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    Physical and chemical miniature biomedical sensors fan be fabricated using thin- and thick-film technology. Devices such as biopotential electrodes; temperature, force, and compliant strain gauge sensors; and ion-selective electrodes have been designed, constructed, and applied to biomedical problems. Sometimes there are advantages to depositing non-conventional materials, thicker films, and thin- thick-film hybrid structures in fabricating biomedical sensors View full abstract»

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  • Multisensor silicon needle for cardiac applications

    Publication Year: 2000 , Page(s): 216 - 219
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    An integrated chemical sensor with multiple ion and temperature sensors, composed of two ISFETs (pH and K+), one platinum pseudo-reference electrode and temperature sensor based on a platinum resistor has been realised by using a CMOS-compatible technology and silicon micromachining. This paper describes a summary of the fabrication process and results of the device characterisation in vitro. The feasibility of the fabrication technology has been demonstrated and all devices have operated satisfactory, with a response showing good sensitivity and linearity. This multisensor will be used in the on-line early detection of myocardial ischemia during cardiac surgery while the heart is artificially arrested (extracorporeal circulation) View full abstract»

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  • Silicon sensors for use in catheters

    Publication Year: 2000 , Page(s): 152 - 155
    Cited by:  Papers (1)  |  Patents (2)
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    To reduce the amount of trauma during medical procedures, so-called minimally invasive procedures are being used. In vascular interventions, catheters are used in the blood vessels. In order to Increase the amount of information a physician has available during these interventions, sensors are needed. To this end, a multiple parameter sensor to measure blood pressure, flow, oxygen saturation and temperature, and a sensor to determine the age of blood clots using colour are developed. In addition, a system to reduce the amount of ionising radiation needed during the positioning of catheters is developed. The special environment puts high demands on the packaging. It needs to protect the sensor from the body, the body from the sensor but allow the parameter to be measured access to the sensor. To overcome the uncertain positioning of the sensor within the vessel, a special sensor catheter needs to be designed View full abstract»

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  • Miniature instrumented robots for mass-scale synthesis and characterization

    Publication Year: 2000 , Page(s): 160 - 164
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    Laboratory robots are currently used for material synthesis via combinatorial chemistry and material testing such as for high throughput screening of pharmaceutical compounds. These robots based on a macro-scale approach in a fixed location are relatively slow and capable of only a few movements per second while lacking in precision over the whole working range. In contrast, the authors' NanoWalker technology aims at developing miniature instrumented wireless robots that can make several thousand movements per second and move with a precision that is as much as several orders of magnitude better than what is achievable with current conventional designs. This paper describes the state of development of this technology as well as the future challenges and possible applications View full abstract»

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  • Miniature pressure acquisition microsystem for wireless in vivo measurements

    Publication Year: 2000 , Page(s): 175 - 179
    Cited by:  Papers (4)  |  Patents (1)
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    Improvement of therapies and diagnosis methods require the acquisition of clinical data with optimal accuracy and reliability. Combination of recent progresses in SOI micro machining and telemetry lead to the development of a new miniature pressure sensor acquisition microsystem to be inserted as close as possible to the organ or the targeted area. Moreover a wireless RF powering and data transmission has been optimized in order to allow a non-invasive acquisition chain View full abstract»

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  • Silicon microbial bioreactor arrays

    Publication Year: 2000 , Page(s): 165 - 170
    Cited by:  Papers (1)  |  Patents (2)
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    The authors present a multi-sensor, multi-well bioreactor platform for high-throughput screening of microbial cultures. The platform is designed to interface directly with industry standard 96-well plates. Each well contains an independently addressable microfabricated sensor and actuator suite that provides closed-loop control over temperature, generates oxygen electrochemically and provides cell density data. Polysilicon, silicon nitride and metal films are deposited and patterned onto silicon wafers using standard silicon processing techniques. Results are presented for an 8-well cell density vs. temperature experiment. Additionally, the authors investigate the use of electrolysis as a means to generate oxygen for bacterial cultures View full abstract»

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  • The thermal effects on deformation processes of the porous materials

    Publication Year: 2000 , Page(s): 435 - 438
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    The modeling of the behavior of porous media has received considerable attention in recent years due not only to its theoretical interest but also to broad technological applications concerning materials such as ceramics, composite materials, bone, and other biological tissues. However, many engineering materials contain defects in the form of cracks, voids and inclusions that can significantly affect their load carrying capabilities. Damage is easily initiates as micro-cracks around an inclusion due to the residual stresses and thermal mismatch between inclusion and matrix properties. Here, the authors are concerned with damaged materials, which due to straining are submitted to modifying microstructure processes, coalescence of voids, and microcracks. The damage phenomenon leads to a progressive deterioration of the material in the sense that its resisting capacity to subsequent loading is diminished. Finally, the computational significance of the model for state-update algorithms is analyzed the context of an explicit time-marching scheme View full abstract»

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  • Design and simulation of a dielectrophoretic-based microsystem for bioparticle handling

    Publication Year: 2000 , Page(s): 429 - 434
    Cited by:  Papers (1)
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    Nowadays, handling of biological objects at the single-cell level is one of the most active and important research fields. To achieve this goal dimensions of the required tools must roughly match those of the bioparticles at issue, usually ranging from 1 to 100 μm. The objective of this paper consists of presenting a microsystem designed for particle microhandling. Some results with polystyrene microspheres are also presented. The operating principle of the aforementioned microsystem hinges upon dielectrophoresis (DEP), which is defined as the lateral motion of electrically neutral matter under the influence of non-uniform electric fields. In practice, the device was fabricated on a silicon substrate onto which interdigitated castellated microelectrodes made of platinum were patterned by lift-off. Moreover, the substrate was micromachined utilising TMAH to anisotropically etch the silicon wafer. Microchamber walls were patterned by PDMS, a photocurable resin which allows a constant sample volume when performing the experiments View full abstract»

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  • New kind of sensors based on amalgamation of fiber optic and seaweed to control pollution in a water

    Publication Year: 2000 , Page(s): 370 - 374
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    Simple remote sensors are considered which are based on different variants of the amalgamation of optical fibers with a “living sensitive element” such as an aquatic plant. Fiber gratings can as provide a sufficient proportion of the propagated light in this “living” fiber's cladding to select a narrow laser line for selective excitation of the chlorophyll molecules to study the mechanisms of photosynthesis in the natural environment View full abstract»

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  • Micro-optics and microengineering in biology and medicine

    Publication Year: 2000 , Page(s): 351 - 355
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    In the field of optics, as in most other domains, physical laws are dependent on the scale of observation. This has the consequence that optical devices in the sub-millimeter range must be understood and conceived differently. Similar considerations are sound for devices making use of interactions of photons with biological matter, at the cellular and tissue scale. In biological tissues, propagation of light is different at the microthan at the millimeter or centimeter scale. This has the advantage that several innovative instruments are presently in development which make use of this specific properties of light propagating at small scale. The examples of micro-endoscopy and micro-holography for tissue imaging and diagnosis are given View full abstract»

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  • Microsyringe based fabrication of high resolution organic structures for bioengineering applications

    Publication Year: 2000 , Page(s): 141 - 144
    Cited by:  Patents (2)
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    Two techniques for controlled deposition of complex architectures are described here. They employ a highly accurate 3D micropositioning system with pressure controlled or volume controlled syringe to deposit nano-liter sized drops of materials. One of the techniques has been used to realise scaffolds for tissue engineering, and the other for fabrication of polymeric actuators. The system has been characterised in terms of deposition parameters such as applied pressure, line width and height and polymer viscosity, and a fluid dynamic model simulating the deposition process has been developed, allowing an accurate prediction of the topological characteristics of the polymer structures View full abstract»

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  • SPR sensor for detection of β2-microglobulin

    Publication Year: 2000 , Page(s): 368 - 369
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    An optical fiber sensor based on the resonant coupling between a surface plasmon wave and a guided mode of the optical fiber sensor has been reported. A technique based on the surface plasmon resonance phenomenon offers a sensitive method for studying the stability of optical sensors. In this work, the authors consider a layered structure consisting of three-layer optical waveguides incorporating silver-monolayer of bovine serum albumin coating layers. Tests include exposing these films to β2-microglobulin have been studied. Experimental and theoretical results have been mutually compared, and the operation characteristics of this novel sensing device have been briefly described View full abstract»

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  • The fitting of the human joint through micro implanted sensors

    Publication Year: 2000 , Page(s): 518 - 520
    Cited by:  Papers (1)  |  Patents (3)
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    The objective of this research is to integrate sensors to develop a fitting device capable of correcting the placement of artificial joints in humans. Improper fitting or balancing of a joint can lead to increased shear forces across the bone prosthesis interface, resulting varus-valgus instability, increased wear to the prosthetic components, and eventual premature failure of the prosthesis. In this study, an array of pressure sensors were placed between the articulating surfaces of a total knee that was surgically placed inside a cadaver knee. A jig was designed that simulates physiologic loads while flexing the knee through its normal range of motion. A distribution of contact pressure was recorded as a function of angle. A 3D PEM model of the knee Joint was built and a stress analysis was performed. The objective is three fold: (1) To understand the human joints and the effects of dynamic loading on the joint as a function of the contact pressure, (2) To correlate the FEM model with the experiment, (3) to predict failure mechanisms due to cyclic loading and improper load distribution View full abstract»

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  • Biomimetics: new tools for an old myth

    Publication Year: 2000 , Page(s): 13 - 17
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    A recent Vth Framework call for proposals, Neuroinformatics for “living artefacts”, is focused on basic research on systems that possess properties akin to those of living organisms to explore new synergies between Neurosciences and Information Technologies. This is evidence of the growing awareness amongst scientists and more significantly, politicians, of the importance of basic research in the field of biomimetics in order to help one better understand the world around one, as well as a stepping stone to improving the man-technology interface. The purpose of this keynote lecture is to lead one along new avenues which combined with state of the art materials science and microfabrication technologies, could provide the key to creating truly biomimetic systems that are capable of dynamic growth, self organisation and possess sensory motor mechanisms View full abstract»

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  • Fabrication and characterization of a biomimetic hydrogel check valve

    Publication Year: 2000 , Page(s): 336 - 339
    Cited by:  Papers (2)
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    A biomimetic hydrogel valve that combines the characteristics of both active and passive valves is fabricated and characterized. The microscopic valve consists of a pair of photopolymerized hydrogel bi-strips with different pH-sensitivities. At physiological pH, the bi-strip undergoes changes in both shape and size to form a valve. The valve mimics anatomic venous valves both functionally and structurally, allowing fluid flow in one direction while restricting flow in the opposite direction. At an applied pressure of 0.71 psi, the forward flow rate was 140 μL/min, compared to a reverse leakage rate of 2.3 μL/min at the same pressure. The valve not only provides directional control of the flow, but also reversibly activates (swells) or deactivates (shrinks) based on the chemical environment of the local fluid. The sealing capabilities of the hydrogel materials are also explored View full abstract»

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  • On-chip microfluidics for proteomic analysis by electrospray ionization/mass spectrometry

    Publication Year: 2000 , Page(s): 439 - 444
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    Describes the development of a silicon integrated demonstrator coupled to an ElectroSpray Ionization source in view of protein analysis by Mass Spectrometry (ESI/MS). The design and the making of basic components: (i) a novel thermal valveless micropump, (ii) a Solid Phase Extraction (SPE) column and (iii) a hollow cantilever nanoemitter constitute the steps of the authors' ongoing technological program which will be achieved by their gathering within a single chip. At present a manifold prototype at a 10 μm scale has been fabricated and is currently being tested View full abstract»

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  • Geometric design and surface morphology of sieve electrodes-nerve regeneration and biocompatibility studies

    Publication Year: 2000 , Page(s): 526 - 530
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    A neural interface could be used to control a limb prosthesis. Such an interface can be achieved by implanting a sieve electrode in the peripheral nerve trunk proximal to an amputation and subsequently record nerve signals intended to control the prostheses. To achieve a long-term stable implantable sieve electrode the implant must fulfil all requirements regarding biocompatibility. This paper therefore addresses cellular reactions in soft tissue induced by silicon and titanium (planar and porous) implants. All implant types displayed the same density of ED1 and ED2 positive macrophages but regarding the capsule formation planar implants displayed an increased capsule formation while the porous implants displayed a constant capsule thickness over time. This paper also addresses the quality of regeneration through four sieve electrode geometries (hole size 30 or 90 μm and transparency 20 or 30%). After 12 weeks of nerve regeneration, electrodes with a hole size of 30 μm and a 30% transparency displayed the most favourable result as judged by the regained gastrocnemius muscle force View full abstract»

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  • Formation of monodispersed microspheres from microfabricated channel array

    Publication Year: 2000 , Page(s): 283 - 287
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    Microspheres (MS), such as emulsion droplets, multiple emulsions, microparticles, microcapsules, and liposomes have been utilized in various industries. The authors proposed a novel microfabricated device for making super-monodispersed emulsion droplets from microchannel (MC) array. The average diameter and the coefficient of variation of the prepared emulsion were 21.3 μm and 4.1%. Using this emulsification technique, the authors prepared the monodispersed solid lipid MS. High melting point edible oils such as hydrogenated fish oil and tripalmitin were used for solid lipid MS. Monodispersed emulsion droplets composed of high melting point edible oil were prepared from MC at 70°C. The prepared emulsion was recovered from the module and cooled down at room temperature, and then the solid lipid MS suspension was obtained. The prepared microspheres had the diameters of approximately 21.7 μm and the coefficient of variation less than 3.6%. Effects of different surfactants, pressure difference on MC emulsification and a diameter distribution of prepared droplets were studied View full abstract»

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  • Multiple diagnostic analyses by enzymatic and chemical reaction on a PDMS microchip

    Publication Year: 2000 , Page(s): 21 - 24
    Cited by:  Papers (1)
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    Microfabrication techniques have been applied to biochemical microreactions and separations on a microchip. The major advantages of biochemical analysis on a chip are reduced reagents, fast reaction, automation, high throughput and portability. The authors report in this paper the development of a multiple diagnostic analyzing system with polydimethylsiloxane (PDMS) microchip. A PDMS microchip is suitable for single-use to avoid cross-contamination in a clinical diagnostic test. Because the PDMS microchip can be produced inexpensively by replica molding with microfabricated master and used with simple optical detection device instead of expensive electrode due to its transparency. Two major blood tests, glucose and albumin assay, were demonstrated on the system by the combination of enzymatic acid chemical reactions and CCD image processing techniques. Ongoing research is to develop a system with sufficient numbers of assays for an easy health checkup. For example, the authors are trying to integrate other enzymatic reactions for blood tests using Oxidase/POD method for uric acid, cholesterol, triacylglycerol and so on View full abstract»

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  • DNA sensor. II. Biolayer generation and characterisation

    Publication Year: 2000 , Page(s): 402 - 406
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    For pt. I see ibid., p. 400-1 (2000). A silicon-based sensor for the direct detection of DNA sequences has been developed. Hybridisation of analyte DNA with complementary sequences immobilised on a silicon transducer induces charge effects that alter the dielectric properties of the surface. This phenomena can be detected by the associated change in the measured capacitance. The biosensor demonstrates sequence specificity and a quantitative response, but is presently hindered by limited sensitivity and poor reproducibility. To address these issues, alternative methods for silicon reconfiguration (see pt. I) and biolayer generation were explored. Biolayer fabrication involved generation of a Si-SiO2-Si3N4 surface rich in hydroxyl groups by plasma etching or chemical treatment. Hydroxyl groups were employed for silanisation with 3-aminopropyltriethoxysilane (3-APTES). Three chemistries were used to covalently attach single stranded probe DNA via the 3-APTES terminal amino group and hybridisation ability was evaluated using a fluorescent technique. Once optimised, this sensor can be elaborated into an array of sensors for sample interrogation with multiple probes. Such an array will be used to determine the antimicrobial susceptibility profile of clinical isolates of Mycobacterium tuberculosis View full abstract»

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  • Growth of myelin figures made of water soluble surfactant

    Publication Year: 2000 , Page(s): 345 - 348
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    The swelling and emulsification dynamics of a soluble lamellar phase of an ionic surfactant is investigated. Upon mixing this surfactant with brine the authors observe a myelinic instabilities at the interface between large vesicles and the aqueous phase. During the early stages of emulsification they observe pearling instabilities. At later stage of emulsification they observe very large tubes with diameters that exceed 50 microns and whose length exceed several order of magnitude its radius View full abstract»

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  • Proposed methods for designing an air in line detection system

    Publication Year: 2000 , Page(s): 146 - 151
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    The incidence of air embolism and subsequent complications during the use of medication infusion pumps has created the need for reliable, sensitive, and continuous means of monitoring the fluid line for the presence of air bubbles. For example, in blood processing, such as dialysis oxygenation, blood fractionation, etc, it is extremely important that the absence of blood, resulting from an air leak or any other reason, is immediately detected so that the tubing can be clamped before an air bubble is allowed to enter the patient's vein along with the blood. The current paper deals with this problem by proposing methods for designing an accurate Air-In-Line Detection system. All the common used techniques have been evaluated. A medication infusion pump was used to experiment with the presented devices. The advantages of the proposed methods can be summarized in the reliability, cost-effectiveness, and small size of the final device View full abstract»

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  • CMOS ISFET-based structures for biomedical applications

    Publication Year: 2000 , Page(s): 502 - 506
    Cited by:  Papers (4)
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    The miniaturization and integration of biomedical sensors is of key importance for improved diagnosis and therapy in the future. These devices integrated monolithically on the same chip together with low-power electronics are suitable for implantable “in vivo” monitoring of arterial blood pH, pCO2 or pO2 changes. This paper deals with the design, fabrication and experimental evaluation of ISFET-based structures realized in an unmodified commercial submicron 0.6 □m CMOS technology. The compatibility study of pH ISFET chemical devices with CMOS circuits is described. Some technology-driven problems associated with using this submicron process for the chemical microsensors are reported. Comparison of the authors' fabricated structures with previously published ISFETs using unmodified standard CMOS technology is given. Research goals are to develop fully integrated CMOS compatible ion-sensitive ISFET devices for implantable biomedical microsystems View full abstract»

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