TY  - JOUR
A1  - Atlas, Glen
A1  - Brealey, David
A1  - Dhar, Sunil
A1  - Dikta, Gerhard
A1  - Singer, Meryvn
T1  - Additional hemodynamic measurements with an esophageal Doppler monitor: a preliminary report of compliance, force, kinetic energy, and afterload in the clinical setting
JF  - Journal of clinical monitoring and computing
N2  - The esophageal Doppler monitor (EDM) is a minimally-invasive hemodynamic device which evaluates both cardiac output (CO), and fluid status, by estimating stroke volume (SV) and calculating heart rate (HR). The measurement of these parameters is based upon a continuous and accurate approximation of distal thoracic aortic blood flow. Furthermore, the peak velocity (PV) and mean acceleration (MA), of aortic blood flow at this anatomic location, are also determined by the EDM. The purpose of this preliminary report is to examine additional clinical hemodynamic calculations of: compliance (C), kinetic energy (KE), force (F), and afterload (TSVRi). These data were derived using both velocity-based measurements, provided by the EDM, as well as other contemporaneous physiologic parameters. Data were obtained from anesthetized patients undergoing surgery or who were in a critical care unit. A graphical inspection of these measurements is presented and discussed with respect to each patient’s clinical situation. When normalized to each of their initial values, F and KE both consistently demonstrated more discriminative power than either PV or MA. The EDM offers additional applications for hemodynamic monitoring. Further research regarding the accuracy, utility, and limitations of these parameters is therefore indicated.
KW  - Acceleration
KW  - Velocity
KW  - Kinetic energy
KW  - Force
KW  - Compliance
KW  - Afterload
KW  - Contractility
KW  - Volume status
KW  - Esophageal Doppler monitor
Y1  - 2012
SN  - 1573-2614
U6  - http://dx.doi.org/10.1007/s10877-012-9386-5
IS  - 26
SP  - 473
EP  - 482
PB  - Springer Nature
CY  - London
ER  - 
TY  - JOUR
A1  - Murib, Mohammed S.
A1  - Tran, Anh Quang
A1  - Ceuninck, Ward de
A1  - Schöning, Michael Josef
A1  - Nesladek, Milos
A1  - Serpengüzel, Ali
A1  - Wagner, Patrick
T1  - Analysis of an optical biosensor based on elastic light scattering from diamond-, glass-, and sapphire microspheres
JF  - Physica Status Solidi A
N2  - Deoxyribonucleic acid (DNA) and protein recognition are now standard tools in biology. In addition, the special optical properties of microsphere resonators expressed by the high quality factor (Q-factor) of whispering gallery modes (WGMs) or morphology dependent resonances (MDRs) have attracted the attention of the biophotonic community. Microsphere-based biosensors are considered as powerful candidates to achieve label-free recognition of single molecules due to the high sensitivity of their WGMs. When the microsphere surface is modified with biomolecules, the effective refractive index and the effective size of the microsphere change resulting in a resonant wavelength shift. The transverse electric (TE) and the transverse magnetic (TM) elastic light scattering intensity of electromagnetic waves at 600 and 1400 nm are numerically calculated for DNA and unspecific binding of proteins to the microsphere surface. The effect of changing the optical properties was studied for diamond (refractive index 2.34), glass (refractive index 1.50), and sapphire (refractive index 1.75) microspheres with a 50 µm radius. The mode spacing, the linewidth of WGMs, and the shift of resonant wavelength due to the change in radius and refractive index, were analyzed by numerical simulations. Preliminary results of unspecific binding of biomolecules are presented. The calculated shift in WGMs can be used for biomolecules detection.
Y1  - 2012
U6  - http://dx.doi.org/10.1002/pssa.201100795
SN  - 1862-6319
N1  - Special Issue: "Fundamentals and Applications of Diamond"
VL  - 209
IS  - 9
SP  - 1804
EP  - 1810
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Mansurov, Z.
A1  - Digel, Ilya
A1  - Biisenbaev, M.
A1  - Savistkaya, I.
A1  - Kistaubaeva, A.
A1  - Akimbekov, N.
A1  - Zhubanova, A.
T1  - Bio-composite material on the basis of carbonized rice husk in biomedicine and environmental applications
JF  - Eurasian Chemico-Technological Journal
Y1  - 2012
U6  - http://dx.doi.org/10.18321/ectj105
SN  - 2522-4867
VL  - 14
IS  - 2
SP  - 115
EP  - 131
PB  - Institute of Combustion Problems
CY  - Almaty
ER  - 
TY  - JOUR
A1  - Kirchner, Patrick
A1  - Reisert, Steffen
A1  - Pütz, Patrick
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Characterisation of polymeric materials as passivation layer for calorimetric H2O2 gas sensors
JF  - Physica Status Solidi (a)
N2  - Calorimetric gas sensors for monitoring the H₂O₂ concentration at elevated temperatures in industrial sterilisation processes have been presented in previous works. These sensors are built up in form of a differential set-up of a catalytically active and passive temperature-sensitive structure. Although, various types of catalytically active dispersions have been studied, the passivation layer has to be established and therefore, chemically as well as physically characterised. In the present work, fluorinated ethylene propylene (FEP), perfluoralkoxy (PFA) and epoxy-based SU-8 photoresist as temperature-stable polymeric materials have been investigated for sensor passivation in terms of their chemical inertness against H₂O₂, their hygroscopic properties as well as their morphology. The polymeric materials were deposited via spin-coating on the temperature-sensitive structure, wherein spin-coated FEP and PFA show slight agglomerates. However, they possess a low absorption of humidity due to their hydrophobic surface, whereas the SU-8 layer has a closed surface but shows a slightly higher absorption of water. All of them were inert against gaseous H₂O₂ during the characterisation in H₂O₂ atmosphere that demonstrates their suitability as passivation layer for calorimetric H₂O₂ gas sensors.
Y1  - 2012
U6  - http://dx.doi.org/10.1002/pssa.201100773
SN  - 1862-6319
VL  - 209
IS  - 5
SP  - 859
EP  - 863
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Schusser, Sebastian
A1  - Poghossian, Arshak
A1  - Bäcker, Matthias
A1  - Leinhos, Marcel
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Characterization of biodegradable polymers with capacitive field-effect sensors
JF  - Sensors and actuators B: Chemical
N2  - In vitro studies of the degradation kinetic of biopolymers are essential for the design and optimization of implantable biomedical devices. In the presented work, a field-effect capacitive sensor has been applied for the real-time and in situ monitoring of degradation processes of biopolymers for the first time. The polymer-covered field-effect sensor is, in principle, capable to detect any changes in bulk, surface and interface properties of the polymer induced by degradation processes. The feasibility of this approach has been experimentally proven by using the commercially available biomedical polymer poly(D,L-lactic acid) (PDLLA) as a model system. PDLLA films of different thicknesses were deposited on the Ta₂O₅-gate surface of the field-effect structure from a polymer solution by means of spin-coating method. The polymer-modified field-effect sensors have been characterized by means of capacitance–voltage and impedance-spectroscopy method. The degradation of the PDLLA was accelerated by changing the degradation medium from neutral (pH 7.2) to alkaline (pH 9) condition, resulting in drastic changes in the capacitance and impedance spectra of the polymer-modified field-effect sensor.
KW  - Impedance spectroscopy
KW  - C–V method
KW  - Real-time monitoring
KW  - Poly(d,l-lacticacid)
KW  - (Bio)degradation
KW  - Field-effect sensor
Y1  - 2012
U6  - http://dx.doi.org/10.1016/j.snb.2012.07.099
SN  - 0925-4005
N1  - Part of special issue "Selected Papers from the 14th International Meeting on Chemical Sensors"
VL  - 187
SP  - 2
EP  - 7
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Miyamoto, K.
A1  - Ichimura, H.
A1  - Wagner, Torsten
A1  - Yoshinobu, T.
A1  - Schöning, Michael Josef
T1  - Chemical Imaging of ion Diffusion in a Microfluidic Channel
JF  - Procedia Engineering
N2  - The chemical imaging sensor is a chemical sensor which is capable of visualizing the spatial distribution of chemical species in sample solution. In this study, a novel measurement system based on the chemical imaging sensor was developed to observe the inside of a Y-shaped microfluidic channel while injecting two sample solutions from two branches. From the collected chemical images, it was clearly observed that the injected solutions formed laminar flows in the microfluidic channel. In addition, ion diffusion across the laminar flows was observed. This label-free method can acquire quantitative data of ion distribution and diffusion in microfluidic devices, which can be used to determine the diffusion coefficients, and therefore, the molecular weights of chemical species in the sample solution.
Y1  - 2012
U6  - http://dx.doi.org/10.1016/j.proeng.2012.09.289
SN  - 1877-7058
N1  - Part of special issue "26th European Conference on Solid-State Transducers, EUROSENSOR 2012"
IS  - 47
SP  - 886
EP  - 889
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Bäcker, Matthias
T1  - Chip-basierte Sensoren für die Biotechnik
Y1  - 2012
SN  - 1611-0854
N1  - 4 Seiten
VL  - 13
IS  - 2
PB  - BIOCOM
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Huck, Christina
A1  - Poghossian, Arshak
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Combined amperometric/field-effect sensor for the detection of dissolved hydrogen
JF  - Sensors and  actuators B: Chemical
N2  - Real-time and reliable monitoring of the biogas process is crucial for a stable and efficient operation of biogas production in order to avoid digester breakdowns. The concentration of dissolved hydrogen (H₂) represents one of the key parameters for biogas process control. In this work, a one-chip integrated combined amperometric/field-effect sensor for monitoring the dissolved H₂ concentration has been developed for biogas applications. The combination of two different transducer principles might allow a more accurate and reliable measurement of dissolved H₂ as an early warning indicator of digester failures. The feasibility of the approach has been demonstrated by simultaneous amperometric/field-effect measurements of dissolved H₂ concentrations in electrolyte solutions. Both, the amperometric and the field-effect transducer show a linear response behaviour in the H₂ concentration range from 0.1 to 3% (v/v) with a slope of 198.4 ± 13.7 nA/% (v/v) and 14.9 ± 0.5 mV/% (v/v), respectively.
Y1  - 2012
U6  - http://dx.doi.org/10.1016/j.snb.2012.10.050
SN  - 0925-4005
N1  - Part of special issue "Selected Papers from the 14th International Meeting on Chemical Sensors"
VL  - 187
SP  - 168
EP  - 173
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Kern, Alexander
A1  - Schelthoff, Christof
A1  - Mathieu, Moritz
T1  - Detaillierte Berechnung der Einfangwirksamkeiten von Fangeinrichtungen
JF  - Elektro-Praktiker
N2  - Im Beitrag wird zunächst das Verfahren eines dynamischen elektro-geometrischen Modells vorgestellt. Dieses arbeitet im Gegensatz zum klassischen Blitzkugel-Verfahren nicht mit konstanten Radien; vielmehr wird der Radius der Blitzkugel variiert. Dabei werden ausschließlich vorhandene und in internationalen Normen anerkannte Ergebnisse, blitzphysikalische Grundlagen und Untersuchungen verwendet, und auf deren Grundlage ein numerisches Verfahren erarbeitet. Mit dem dynamischen elektro-geometrischen Modell werden dann einige Beispiele des Schutzes mit Fangstangen, die gemäß dem klassischen Blitzkugel-Verfahren nach DIN EN 62305-3 für die Schutzklassen I – II – III – IV geplant sind, untersucht. Es wird gezeigt, dass die Einfangwirksamkeiten wesentlich höher sind als in der Normenreihe DIN EN 62305 selbst angegeben. Grund dafür ist die Tatsache, dass das Blitzkugel-Verfahren sehr konservativ aufgebaut ist und dem Planer von Blitzschutzsystemen nur die möglichen Stellen für einen Einschlag aufzeigt, ohne eine Bewertung der Einschlagshäufigkeit zu liefern. Andererseits bedeutet dies jedoch, dass man mit dem klassischen Blitzkugel-Verfahren stets auf der „sicheren Seite“ liegt.
Y1  - 2012
SN  - 0013-5569
VL  - 66
IS  - 4
PB  - Huss Medien
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Hasan, Istabrak
A1  - Keil, Ludger
A1  - Staat, Manfred
A1  - Wahl, Gerhard
A1  - Bourauel, Christoph
T1  - Determination of the frictional coefficient of the implant-antler interface : experimental approach
JF  - Biomedical Engineering / Biomedizinische Technik
N2  - The similar bone structure of reindeer antler to human bone permits studying the osseointegration of dental implants in the jawbone. As the friction is one of the major factors that have a significant influence on the initial stability of immediately loaded dental implants, it is essential to define the frictional coefficient of the implant-antler interface. In this study, the kinetic frictional forces at the implant-antler interface were measured experimentally using an optomechanical setup and a stepping motor controller under different axial loads and sliding velocities. The corresponding mean values of the static and kinetic frictional coefficients were within the range of 0.5–0.7 and 0.3–0.5, respectively. An increase in the frictional forces with increasing applied axial loads was registered. The measurements showed an evidence of a decrease in the magnitude of the frictional coefficient with increasing sliding velocity. The results of this study provide a considerable assessment to clarify the suitable frictional coefficient to be used in the finite element contact analysis of antler specimens.
Y1  - 2012
SN  - 1862-278X
VL  - 57
IS  - 5
SP  - 359
EP  - 363
PB  - De Gruyter
CY  - Berlin
ER  -