TY - JOUR
A1 - Horbach, Andreas
A1 - Staat, Manfred
A1 - Perez-Viana, Daniel
A1 - Simmen, Hans-Peter
A1 - Neuhaus, Valentin
A1 - Pape, Hans-Christoph
A1 - Prescher, Andreas
A1 - Ciritsis, Bernhard
T1 - Biomechanical in vitro examination of a standardized low-volume tubular femoroplasty
JF - Clinical Biomechanics
N2 - Background
Osteoporosis is associated with the risk of fractures near the hip. Age and comorbidities increase the perioperative risk. Due to the ageing population, fracture of the proximal femur also proves to be a socio-economic problem. Preventive surgical measures have hardly been used so far.
Methods
10 pairs of human femora from fresh cadavers were divided into control and low-volume femoroplasty groups and subjected to a Hayes fall-loading fracture test. The results of the respective localization and classification of the fracture site, the Singh index determined by computed tomography (CT) examination and the parameters in terms of fracture force, work to fracture and stiffness were evaluated statistically and with the finite element method. In addition, a finite element parametric study with different position angles and variants of the tubular geometry of the femoroplasty was performed.
Findings
Compared to the control group, the work to fracture could be increased by 33.2%. The fracture force increased by 19.9%. The used technique and instrumentation proved to be standardized and reproducible with an average poly(methyl methacrylate) volume of 10.5 ml. The parametric study showed the best results for the selected angle and geometry.
Interpretation
The cadaver studies demonstrated the biomechanical efficacy of the low-volume tubular femoroplasty. The numerical calculations confirmed the optimal choice of positioning as well as the inner and outer diameter of the tube in this setting. The standardized minimally invasive technique with the instruments developed for it could be used in further comparative studies to confirm the measured biomechanical results.
Y1 - 2020
U6 - https://doi.org/10.1016/j.clinbiomech.2020.105104
VL - 80
IS - Art. 105104
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Horbach, Andreas
A1 - Staat, Manfred
T1 - Optical strain measurement for the modeling of surgical meshes and their porosity
JF - Current Directions in Biomedical Engineering
N2 - The porosity of surgical meshes makes them flexible for large elastic deformation and establishes the healing conditions of good tissue in growth. The biomechanic modeling of orthotropic and compressible materials requires new materials models and simulstaneoaus fit of deformation in the load direction as well as trannsversely to to load. This nonlinear modeling can be achieved by an optical deformation measurement. At the same time the full field deformation measurement allows the dermination of the change of porosity with deformation. Also the socalled effective porosity, which has been defined to asses the tisssue interatcion with the mesh implants, can be determined from the global deformation of the surgical meshes.
Y1 - 2018
U6 - https://doi.org/10.1515/cdbme-2018-0045
SN - 2364-5504
VL - Band 4
IS - 1
SP - 181
EP - 184
PB - De Gruyter
CY - Berlin
ER -
TY - JOUR
A1 - Horbach, Andreas
A1 - Duong, Minh Tuan
A1 - Staat, Manfred
T1 - Modelling of compressible and orthotropic surgical mesh implants based on optical deformation measurement
JF - Journal of the mechanical behavior of biomedical materials
Y1 - 2017
U6 - https://doi.org/10.1016/j.jmbbm.2017.06.012
SN - 1751-6161
VL - 74
SP - 400
EP - 410
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Honarvarfard, Elham
A1 - Gamella, Maria
A1 - Poghossian, Arshak
A1 - Schöning, Michael Josef
A1 - Katz, Evgeny
T1 - An enzyme-based reversible Controlled NOT (CNOT) logic gate operating on a semiconductor transducer
JF - Applied Materials Today
N2 - An enzyme-based biocatalytic system mimicking operation of a logically reversible Controlled NOT (CNOT) gate has been interfaced with semiconductor electronic transducers. Electrolyte–insulator–semiconductor (EIS) structures have been used to transduce chemical changes produced by the enzyme system to an electronically readable capacitive output signal using field-effect features of the EIS device. Two enzymes, urease and esterase, were immobilized on the insulating interface of EIS structure producing local pH changes performing XOR logic operation controlled by various combinations of the input signals represented by urea and ethyl butyrate. Another EIS transducer was functionalized with esterase only, thus performing Identity (ID) logic operation for the ethyl butyrate input. Both semiconductor devices assembled in parallel operated as a logically reversible CNOT gate. The present system, despite its simplicity, demonstrated for the first time logically reversible function of the enzyme system transduced electronically with the semiconductor devices. The biomolecular realization of a CNOT gate interfaced with semiconductors is promising for integration into complex biomolecular networks and future biosensor/biomedical applications.
KW - Electrolyte–insulator–semiconductor
KW - Capacitive field-effect
KW - CNOT
KW - XOR
KW - Enzyme logic gate
Y1 - 2017
U6 - https://doi.org/10.1016/j.apmt.2017.08.003
SN - 2352-9407
VL - 9
SP - 266
EP - 270
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Honarvarfard, Elham
A1 - Gamella, Maria
A1 - Channaveerappa, Devika
A1 - Darie, Costel C.
A1 - Poghossian, Arshak
A1 - Schöning, Michael Josef
A1 - Katz, Evgeny
T1 - Electrochemically Stimulated Insulin Release from a Modified Graphene–functionalized Carbon Fiber Electrode
JF - Electroanalysis
N2 - A graphene-functionalized carbon fiber electrode was modified with adsorbed polyethylenimine to introduce amino functionalities and then with trigonelline and 4-carboxyphenylboronic acid covalently bound to the amino groups. The trigonelline species containing quarterized pyridine groups produced positive charge on the electrode surface regardless of the pH value, while the phenylboronic acid species were neutral below pH 8 and negatively charged above pH 9 (note that their pKa=8.4). The total charge on the monolayer-modified electrode was positive at the neutral pH and negative at pH > 9. Note that 4-carboxyphenylboronic acid was attached to the electrode surface in molar excess to trigonelline, thus allowing the negative charge to dominate on the electrode surface at basic pH. Negatively charged fluorescent dye-labeled insulin (insulin-FITC) was loaded on the modified electrode surface at pH 7.0 due to its electrostatic attraction to the positively charged interface. The local pH in close vicinity to the electrode surface was increased to ca. 9–10 due to consumption of H+ ions upon electrochemical reduction of oxygen proceeding at the potential of −1.0 V (vs. Ag/AgCl) applied on the modified electrode. The process resulted in recharging of the electrode surface to the negative value due to the formation of the negative charge on the phenylboronic acid groups, thus resulting in the electrostatic repulsion of insulin-FITC and stimulating its release from the electrode surface. The insulin release was characterized by fluorescence spectroscopy (using the FITC-labeled insulin), by electrochemical measurements on an iridium oxide, IrOx, electrode and by mass spectrometry. The graphene-functionalized carbon fiber electrode demonstrated significant advantages in the signal-stimulated insulin release comparing with the carbon fiber electrode without the graphene species.
Y1 - 2017
U6 - https://doi.org/10.1002/elan.201700095
SN - 1521-4109
VL - 29
IS - 6
SP - 1543
EP - 1553
PB - Wiley-VCH
CY - Weinheim
ER -
TY - JOUR
A1 - Hirschfeld, J. A.
A1 - Lustfeld, H.
A1 - Reißel, Martin
A1 - Steffen, B.
T1 - A novel scheme for precise diagnostics and effective stabilization of currents in a fuel cell stack
JF - International Journal of Energy Research. 34 (2010), H. 3
Y1 - 2010
SN - 0363-907X
SP - 293
EP - 301
ER -
TY - JOUR
A1 - Hirschfeld, J. A.
A1 - Lustfeld, H.
A1 - Reißel, Martin
A1 - Steffen, B.
T1 - Tomographic diagnostics of current distributions in a fuel cell stack
JF - International Journal of Energy Research
Y1 - 2010
SN - 0363-907X
VL - 34
IS - 3
SP - 284
EP - 292
ER -
TY - JOUR
A1 - Hillen, Walter
A1 - Winterschlade, T.
A1 - Krone, J.
T1 - Erkennung lokaler Bildfehler in Röntgenbildverstärkern durch parallel arbeitende Bildrechner
JF - Parallele Datenverarbeitung : Entwurfsmethoden, Bildverarbeitung, Simulation ; Workshop der Arbeitsgemeinschaft "Parallelverarbeitung an Fachhochschulen in NRW" am 19.6.1998 in Bochum / Jörg Krone ... (Hrsg.)
Y1 - 1998
SN - 3-18-355310-4
N1 - Fortschritt-Berichte VDI : Reihe 10, Informatik, Kommunikationstechnik ; 553
SP - 88
EP - 94
PB - VDI-Verl.
CY - Düsseldorf
ER -
TY - JOUR
A1 - Hillen, Walter
A1 - Unglauben, F.
A1 - Wirtz, G.
T1 - Architectures and Modeling of Distributed Image Information Systems. Unglauben, F.; Hillen, W.; Wirtz, G.
JF - Proceedings : July 14 - 18, 2002, Orlando, Florida, USA ; [jointly with the 8th International Conference on Information Systems Analysis and Synthesis (ISAS 2002)] / organized by IIIS, International Institute of Informatics and Systemics. Ed. by Nagib Callaos
Y1 - 2002
SN - 9800781501
N1 - World Multiconference on Systemics, Cybernetics and Informatics ; (6, 2002, Orlando, Fla.) ; International Conference on Information Systems, Analysis and Synthesis ; (8, 2002, Orlando, Fla.) ; International Institute of Informatics and Systemics ; World Multiconference on Systemics, Cybernetics and Informatics ; (6 : ; 2002.07.14-18 : ; Orlando, Fla.) ; SCI 2002 ; (6 : ; 2002.07.14-18 : ; Orlando, Fla.) ; International Conference on Information Systems Analysis and Synthesis ; (8 : ; 2002.07.14-18 : ; Orlando, Fla.) ; ISAS 2002 ; (8 : ; 2002.07.14-18 : ; Orlando, Fla.)
PB - IIIS
CY - Orlando, Fla.
ER -
TY - JOUR
A1 - Hillen, Walter
A1 - Unglauben, F.
A1 - Murdfield, M.
T1 - Study of Database Connections for a Java Medical Image Viewer. Unglauben, F.; Hillen, W.; Murdfield, M.
JF - Intelligente, innovative Produktentwicklung für die industrielle Praxis. Blümel, Bernd; Stenzel, Horst [Hrsg.]
Y1 - 2001
N1 - Forschungsverbund Multimedia an Fachhochschulen in Nordrhein-Westfalen
SP - 29
EP - 33
PB - Forschungverbund Multimedia an Fachhochschulen
CY - Köln
ER -
TY - JOUR
A1 - Hillen, Walter
A1 - Unglauben, F.
A1 - Murdfield, M.
T1 - Evaluation of two- and three-tier database connections for a java-based medical image viewer. Unglauben, F.; Hillen, W.; Murdfield, M.
JF - Bildverarbeitung für die Medizin 2000 : Algorithmen - Systeme - Anwendungen ; proceedings des Workshops [Bildverarbeitung für die Medizin] vom 12. - 14. März 2000 in München / Alexander Horsch ... [Hrsg.]
Y1 - 2000
SN - 3-540-67123-4
N1 - Inhaltsverzeichnis; Workshop Bildverarbeitung für die Medizin <2000, München>
SP - 203
EP - 207
PB - Springer
CY - Berlin [u.a.]
ER -
TY - JOUR
A1 - Hillen, Walter
A1 - Unglauben, F.
A1 - Kondring, T.
T1 - Java DICOM Viewer für die Teleradiologie. Unglauben, F.; Hillen, W.; Kondring, T.
JF - Bildverarbeitung für die Medizin 2001 : Algorithmen, Systeme, Anwendungen ; proceedings des Workshops [Bildverarbeitung für die Medizin] vom 4. - 6. März 2001 in Lübeck / Heinz Handels ... [Hrsg.]
Y1 - 2001
SN - 3-540-41690-0
N1 - Inhaltsverzeichnis; Workshop Bildverarbeitung für die Medizin <2001, Lübeck>
SP - 404
EP - 408
PB - Springer
CY - Berlin [u.a.]
ER -
TY - JOUR
A1 - Hillen, Walter
A1 - Unglauben, F.
A1 - Indefrey, F.
T1 - Java Image Viewer zur Darstellung und Verarbeitung medizinischer Bilddaten in Rechnernetzen
JF - Intelligente, innovative Produktentwicklung für die industrielle Praxis. Stenzel, Horst [Hrsg.]
Y1 - 2001
N1 - Forschungsverbund Multimedia an Fachhochschulen in Nordrhein-Westfalen
SP - 23
EP - 28
PB - Forschungverbund Multimedia an Fachhochschulen
CY - Köln
ER -
TY - JOUR
A1 - Hillen, Walter
A1 - Schmitt, W.
A1 - Bockemühl, J.
T1 - Signal-to-Noise Performance of a digital dental X-ray Detector
JF - Computer assisted radiology : proceedings of the International Symposium on Computer and Communication Systems for Image Guided Diagnosis and Therapy / CAR '95 Berlin, June 21 - 24, 1995. Ed. by H. U. Lemke
Y1 - 1995
SN - 3-540-59177-X
N1 - CAR <6, 1995, Berlin>
PB - Springer
CY - Berlin [u.a.]
ER -
TY - JOUR
A1 - Hillen, Walter
A1 - Schiebel, U.
A1 - Zaengel, T.
T1 - A selenium-based detector for digital slot-radiography
JF - Medical Imaging II
Y1 - 1988
N1 - Proceedings of SPIE ; 914
SP - 253
ER -
TY - JOUR
A1 - Hillen, Walter
A1 - Schiebel, U.
A1 - Zaengel, T.
T1 - Image quality in selenium-based digital radiography. Schiebel, U.; Hillen, W.; Zaengel, T.
JF - Medical Imaging
Y1 - 1986
N1 - Proceedings of SPIE ; 626
SP - 176
ER -
TY - JOUR
A1 - Hillen, Walter
A1 - Schiebel, U.
A1 - Zaengel, T.
T1 - Imaging performance of a digital storage phosphor system
JF - Medical Physics. 14 (1987), H. 5
Y1 - 1987
SN - 0094-2405
SP - 744
EP - 751
ER -
TY - JOUR
A1 - Hillen, Walter
A1 - Rupp, S.
A1 - Schiebel, U.
A1 - Zaengel, Thomas T.
T1 - Imaging performance of a selenium-based detector for high-resolution radiography
JF - Medical Imaging III: Image Formation
Y1 - 1989
SN - 0-8194-0125-0
N1 - Proceedings of SPIE ; 1090
SP - 296
ER -
TY - JOUR
A1 - Hillen, Walter
A1 - Lehmann, T.
A1 - Horn, H.
A1 - Schmitt, W.
T1 - IDEFIX - Identifizierung dentaler Fixturen mit morphologischen Filtern. Lehmann, T.; Horn, H.; Schmitt, W., Hillen, W.; Spitzer, K.
JF - Bildverarbeitung für die Medizin : Algorithmen - Systeme - Anwendungen ; proceedings des Aachener Workshops am 8. und 9. November 1996 / Institut für Medizinische Informatik und Biometrie der RWTH Aachen. Hrsg. von Thomas Lehmann ...
Y1 - 1996
SN - 3-86073-519-5
SP - 327
EP - 332
PB - Verl. der Augustinus-Buchh.
CY - Aachen
ER -
TY - JOUR
A1 - Hillen, Walter
A1 - Lehmann, T.
A1 - Horn, H.
A1 - Schmitt, W.
T1 - Identification of Dental Fixtures in Intraoral X-rays. Lehmann, T.; Hillen, W.; Horn, H.; Schmitt, W.
JF - Medical imaging 1996 : image processing ; 12 - 15 February 1996, Newport Beach, California / Murray H. Loew ... chairs/ed.
Y1 - 1996
SN - 0-8194-2085-9
N1 - Proceedings of SPIE; 2710
SP - 584
EP - 584
PB - SPIE - The International Society for Optical Engineering
CY - Bellingham, Wash.
ER -