Institut für Medizintechnik und Medizininformatik
Dauerhafte URI für die Sammlunghttps://irf.fhnw.ch/handle/11654/23
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Ergebnisse nach Hochschule und Institut
Publikation Backtrainer. Computer-aided therapy system with augmented feedback for the lower back(SciTePress, 2009) Brodbeck, Dominique; Degen, Markus; Stanimirov, Michael; Kool, Jan; Scheermesser, Mandy; Oesch, Peter; Neuhaus, Cornelia; Azevedo, Luis; Londral, AnaLow back pain is an important problem in industrialized countries. Two key factors limit the effectiveness of physiotherapy: low compliance of patients with repetitive movement exercises, and inadequate awareness of patients of their own posture. The Backtrainer system addresses these problems by real-time monitoring of the spine position, by providing a framework for most common physiotherapy exercises for the low back, and by providing feedback to patients in a motivating way. A minimal sensor configuration was identified as two inertial sensors that measure the orientation of the lower back at two points with three degrees of freedom. The software was designed as a flexible platform to experiment with different hardware, and with various feedback modalities. Basic exercises for two types of movements are provided: mobilizing and stabilizing. We developed visual feedback - abstract as well as in the form of a virtual reality game - and complemented the on-screen graphics with an ambient feedback device. The system was evaluated during five weeks in a rehabilitation clinic with 26 patients and 15 physiotherapists. Subjective satisfaction of subjects was good, and we interpret the results as encouraging indication for the adoption of such a therapy support system by both patients and therapists.04B - Beitrag KonferenzschriftPublikation Molecular assembly and self‐assembly: molecular nanoscience for future technologies(2003) de Wild, Michael; Berner, Simon; Suzuki, Hitoshi; Ramoino, Luca; Baratoff, Alexis; Jung, Thomas A.In this review the emerging science of single molecules is discussed in the perspective of nanoscale molecular functions and devices. New methods for the controlled assembly of well-defined molecular nanostructures are pre- sented: self assembly and single molecular positioning. The observation and selective modification of conformation, electronics, and molecular mechanics of individual molecules and molecular assemblies by scanning probes is dem- onstrated. To complement this scientific review, some of the possible conse- quences and visions for future developments are discussed, as far as they derive from the presented systems. The prospects of nanoscale science to stim- ulate technological evolution are exemplified.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Hematocrit measurement - a high precision on-line measurement system based on impedance spectroscopy for use in hemodialysis machines(2009) Trebbels, Dennis; Zengerle, Roland; Hradetzky, DavidThis paper presents a unique technical approach to measure the proportion of blood volume occupied by red blood cells, the hematocrit value (HCT) on-line and in-line. A practical method has been developed to measure without the need for extracting blood samples out of an existing extracorporeal blood circulation system. The new sensor is based on Impedance Spectroscopy and measures electrical properties of the blood at various frequencies. In order to achieve the required precision resolution the sensor geometry has been optimized by Finite Element Analysis. For sensor readout a digital measurement circuitry based on cheap standard components is developed and allows practical implementation of HCT-sensor devices for the first time. Special care has been taken in order to compensate for the temperature effects.04B - Beitrag KonferenzschriftPublikation Interferometric label-free biomolecular detection system(IOP Publishing Ltd, 2006) Hradetzky, David; Mueller, Claas; Reinecke, HolgerThis work presents a simple evanescent wave sensing system based on an interferometric approach, suitable to meet the requirements of label-free sensor systems for detecting biomolecular interactions. It represents a basic concept towards label-free detection systems in various applications. The basic objectives of transducers for evanescent wave sensing are discussed. An optical detection system based on a interferometric approach using Young's double slit configuration is discussed, set-up and characterized. With refractometric measurements of various sucrose dilutions, the performance of the pure optical set-up is evaluated.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Interferometrisches Biosensor System(2001) Wikerstål, Andreas; Brandenburg, Albrecht; Hradetzky, David; Krauter, Ralf; Künzel, Christa; Schulte, Heinrich; Stefan, Monika04B - Beitrag KonferenzschriftPublikation Label free detection of biomolecular interactions(IEEE, 2005) Hradetzky, David; Müller, Claas; Reinecke, HolgerThis work presents a simple evanescent wave sensing system based on an interferometric approach suitable to meet the demands on label free sensor systems for the detection of biomolecular interactions especially. It is representing a basic concept towards high throughput application. The system performance and reproducibility was evaluated with refractometric measurements of sucrose dilutions. A mean resolution of the effective refractive index of 3sigma(Deltamacrnmacr eff )=0.9middot10 -6 without averaging and a reproducibility below sigma r =0.1middot10 -6 were achieved. The suitability for the detection of biomolecular interactions was validated with the detection of a DNA hybridization04B - Beitrag KonferenzschriftPublikation Miniaturisierte Sensorplattform zur markierungsfreien Detektion biomolekularer Interaktionen(Cuvillier Verlag, 2005) Hradetzky, David02 - MonographiePublikation Capacitive on-line hematocrit sensor design based on impedance spectroscopy for use in hemodialysis machines(IEEE, 2009) Trebbels, D.; Hradetzky, David; Zengerle, R.This paper presents a new design for an on-line and in-line hematocrit (HCT) sensor. Special feature of the sensor is the capability to measure the hematocrit of a blood sample inside standard plastic tubing widely used in medical equipment. No blood sample has to be extracted out of existing extracorporeal blood circulation systems such as hemodialysis machines or heart-lung machines. The sensor principle is based on electrical impedance spectroscopy. Dielectric properties of the blood and the plastic tubing are measured at various frequencies. In order to optimize the sensitivity, a unique electrode configuration is developed and optimized by Finite Element Simulation. The new electrode design optimizes the overall sensitivity of the sensor towards a change in dielectric properties of the blood caused by the HCT value and therefore decreases the sensitivity to side effects caused by temperature drift and component tolerances. As a result of the optimized overall sensor performance the complexity of a sensor readout circuitry can be reduced to a minimum which leads to an unmatched price-performance ratio for a complete measurement system.04B - Beitrag KonferenzschriftPublikation Molecular assembly and self-assembly. Molecular nanoscience for future technologies(Schweizerische Chemische Gesellschaft, 2002) de Wild, Michael; Berner, Simon; Suzuki, Hitoshi; Ramoino, Luca; Baratoff, Alexis; Jung, Thomas A.In this review the emerging science of single molecules is discussed from the perspective of nanoscale molecular functions and devices. New methods for the controlled assembly of well-defined mo lecular nanostructures are presented: self assembly and single molecular positioning. The observation and selective modification of conformation, electronics, and molecular mechanics of individual molecules and molecular assemblies by scanning probes are demonstrated. To complement this scientific review, some of the possible consequences and visions for future developments are discussed, as far as they derive from the presented systems. Here, the prospects of nanoscale science to stimulate technological evolution are ex emplified.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Fabrication of TiO2‐coated epoxy replicas with identical dual‐type surface topographies used in cell culture assays(Wiley, 01/2009) Schuler, Martin; Kunzler, Tobias P.; de Wild, Michael; Sprecher, Christoph M.; Trentin, Diana; Brunette, Donald M.; Textor, Marcus; Tosatti, Samuele G. P.The goal of this study was to reproducibly generate samples with complex surface topographies and chemistries identical to a "master surface" and to test their response in cell culture using rat calvarial cells. Negative replicas of dual-type topography were fabricated using dental impression material with half of the surface exhibiting smooth and rough topography, respectively. Positive epoxy resin replicas were cast from the same negative replica eight times consecutively and coated with a 60-nm thin film of titanium dioxide using a vapor deposition technique. Atomic force microscopy, scanning electron microscopy, confocal white light microscopy, and X-ray photoelectron spectroscopy indicated that TiO2-coated epoxy replicas had surface topographical features and surface compositions nearly indistinguishable from the original titanium master surfaces. The described technique showed high reproducibility over at least eight generations of replication using the same negative replica. Rat calvarial osteoblasts proliferated just as well on dual topography surfaces as on single topography surfaces. The advantage of the dual-type substrates is that they facilitate comparison within a single culture dish, thus eliminating dish-to-dish variation as well as saving material, time and costs compared to the usual method of evaluating surfaces in separate dishes.01A - Beitrag in wissenschaftlicher Zeitschrift