TY - JOUR A1 - Achtsnicht, Stefan A1 - Pourshahidi, Ali Mohammad A1 - Offenhäusser, Andreas A1 - Krause, Hans-Joachim T1 - Multiplex detection of different magnetic beads using frequency scanning in magnetic frequency mixing technique JF - Sensors N2 - In modern bioanalytical methods, it is often desired to detect several targets in one sample within one measurement. Immunological methods including those that use superparamagnetic beads are an important group of techniques for these applications. The goal of this work is to investigate the feasibility of simultaneously detecting different superparamagnetic beads acting as markers using the magnetic frequency mixing technique. The frequency of the magnetic excitation field is scanned while the lower driving frequency is kept constant. Due to the particles’ nonlinear magnetization, mixing frequencies are generated. To record their amplitude and phase information, a direct digitization of the pickup-coil’s signal with subsequent Fast Fourier Transformation is performed. By synchronizing both magnetic beads using frequency scanning in magnetic frequency mixing technique magnetic fields, a stable phase information is gained. In this research, it is shown that the amplitude of the dominant mixing component is proportional to the amount of superparamagnetic beads inside a sample. Additionally, it is shown that the phase does not show this behaviour. Excitation frequency scans of different bead types were performed, showing different phases, without correlation to their diverse amplitudes. Two commercially available beads were selected and a determination of their amount in a mixture is performed as a demonstration for multiplex measurements. KW - frequency mixing magnetic detection KW - magnetic sandwich immunoassay KW - multiparametric immunoassays Y1 - 2019 U6 - https://doi.org/10.3390/s19112599 SN - 1424-8220 VL - 19 IS - 11 PB - MDPI CY - Basel ER - TY - JOUR A1 - Achtsnicht, Stefan A1 - Schönenborn, Kristina A1 - Offenhäusser, Andreas A1 - Krause, Hans-Joachim T1 - Measurement of the magnetophoretic velocity of different superparamagnetic beads JF - Journal of Magnetism and Magnetic Materials N2 - The movement of magnetic beads due to a magnetic field gradient is of great interest in different application fields. In this report we present a technique based on a magnetic tweezers setup to measure the velocity factor of magnetically actuated individual superparamagnetic beads in a fluidic environment. Several beads can be tracked simultaneously in order to gain and improve statistics. Furthermore we show our results for different beads with hydrodynamic diameters between 200 and 1000 nm from diverse manufacturers. These measurement data can, for example, be used to determine design parameters for a magnetic separation system, like maximum flow rate and minimum separation time, or to select suitable beads for fixed experimental requirements. KW - magnetophoretic velocity KW - superparamagnetic bead KW - magnetic tweezers KW - magnetic separation KW - magnetic actuation Y1 - 2019 U6 - https://doi.org/10.1016/j.jmmm.2018.10.066 SN - 0304-8853 VL - 477 IS - 1 SP - 244 EP - 248 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Achtsnicht, Stefan A1 - Tödter, Julia A1 - Niehues, Julia A1 - Telöken, Matthias A1 - Offenhäusser, Andreas A1 - Krause, Hans-Joachim A1 - Schröper, Florian T1 - 3D printed modular immunofiltration columns for frequency mixing-based multiplex magnetic immunodetection JF - Sensors N2 - For performing point-of-care molecular diagnostics, magnetic immunoassays constitute a promising alternative to established enzyme-linked immunosorbent assays (ELISA) because they are fast, robust and sensitive. Simultaneous detection of multiple biomolecular targets from one body fluid sample is desired. The aim of this work is to show that multiplex magnetic immunodetection based on magnetic frequency mixing by means of modular immunofiltration columns prepared for different targets is feasible. By calculations of the magnetic response signal, the required spacing between the modules was determined. Immunofiltration columns were manufactured by 3D printing and antibody immobilization was performed in a batch approach. It was shown experimentally that two different target molecules in a sample solution could be individually detected in a single assaying step with magnetic measurements of the corresponding immobilization filters. The arrangement order of the filters and of a negative control did not influence the results. Thus, a simple and reliable approach to multi-target magnetic immunodetection was demonstrated. Y1 - 2019 U6 - https://doi.org/10.3390/s19010148 SN - 1424-8220 VL - 19 IS - 1 PB - MDPI CY - Basel ER - TY - JOUR A1 - Ackermann, Hans-Josef T1 - Single chip hardware support for rasterization and texture mapping JF - Computers & graphics : CAG ; an international journal of applications in computer graphics. 20 (1996), H. 4 Y1 - 1996 SN - 0097-8493 SP - 503 EP - 514 ER - TY - BOOK A1 - Ackermann, Hans-Josef T1 - Hardware-Unterstützung für effiziente Dreiecksrasterisierung und texture mapping Y1 - 1996 SN - 3826512081 N1 - zugl.: Techn. Hochsch., Diss.--Darmstadt, 1995. PB - Shaker CY - Aachen ER - TY - JOUR A1 - Ackermann, Hans-Josef T1 - Morphing- und Level-of-Detail-Techniken zur Reduzierung des Darstellungsaufwands bei Echtzeit-Sichtsimulationen JF - Digital controls for high resolution display : JESSI Europrojekt No. 3203000, AE-36 ; Abschlußbericht ; Laufzeit u. Berichtszeitraum: 01.01.1995 bis 31.12.1996. Y1 - 1997 CY - Erlangen ER - TY - JOUR A1 - Ackermann, Hans-Josef A1 - Jäger, Michael A1 - Osterfeld, Utz A1 - Hornung, Christoph T1 - Building a Multimedia ISDN PC / Jäger, Michael ; Osterfeld, Utz ; Ackermann, Hans-Josef ; Hornung, Christoph JF - Institute of Electrical and Electronics Engineers: IEEE computer graphics and applications. 13 (1993), H. 5 Y1 - 1993 SN - 0272-1716 SP - 24 EP - 33 ER - TY - BOOK A1 - Ackermann, Hans-Josef A1 - Mehl, Max A1 - Peischl, Markus T1 - Modulares Graphik-Subsystem für die Echtzeitdarstellung von 3D-Anwendungen : Abschlußbericht ; Contract NT 2815-A-8 / Hans-Josef Ackermann; Max Mehl; Markus Peischl. Fachbereich Informatik, Technische Hochschule Darmstadt; Bundesministerium für Forschung und Technologie, Bonn Y1 - 1990 N1 - Forschungs- und Arbeitsberichte des Fachgebietes Graphisch-Interaktive Systeme, Technische Hochschule Darmstadt ; 90-4 PB - Techn. Hochschule CY - Darmstadt ER - TY - THES A1 - Ackermann, Vincent T1 - Filos : Design eines Front-Ends für das robotergeführte Laser-Osteotom-System STELLA. N2 - In der Abschlussarbeit „FILOS“ wurde in Zusammenarbeit mit dem Fraunhofer-Institut für Lasertechnik (ILT) ein Front-End für das laserbasierte Osteotom STELLA entwickelt. STELLA soll Kraniotomie (das Eröffnen des Schädels) im wachen Zustand ermöglichen und erfordert eine benutzerfreundliche Bedienungsplattform sowie ein funktionales und ästhetisches Design. Das Ziel von „FILOS“ war es, ein Gehäuse zu entwerfen, das den medizinischen Anforderungen entspricht, und ein Bedienkonzept zu entwickeln, dass die Akzeptanz bei Patient:innen und Anwender:innen fördert. Durch Expert:innen-Interviews mit Neurochirurg:innen und enge Zusammenarbeit mit dem ILT wurde ein durchdachtes Design entwickelt. Dieses soll den Anforderungen der Anwender:innen gerecht werden, das zukünftige Operationssystem repräsentieren und somit einen Mehrwert in der Medizin schaffen. KW - Wachoperation KW - Laserchirurgie KW - Medizintechnik KW - Cobot KW - Industrial Design Y1 - 2024 N1 - Für diese Arbeit steht kein Volltext zur Verfügung. PB - FH Aachen CY - Aachen ER - TY - CHAP A1 - Adams, Moritz A1 - Losekamm, Martin J. A1 - Czupalla, Markus T1 - Development of the Thermal Control System for the RadMap Telescope Experiment on the International Space Station T2 - International Conference on Environmental Systems Y1 - 2020 N1 - 2020 International Conference on Environmental Systems, 12. Juli 2020 – 16. Juli 2020, Lissabon SP - 1 EP - 10 ER -