Refine
Document Type
- conference proceeding (article) (4)
- Article (1)
- Part of a Book (1)
- conference talk (1)
- Part of Periodical (1)
- Preprint (1)
Is part of the Bibliography
- no (9)
Keywords
- ANATOMY (1)
- COLLATERAL LIGAMENT (1)
- Drift-free SPR (1)
- Hardware-native sensing (1)
- Knee balancer (1)
- Ligament balance (1)
- Ligament stiffness (1)
- Medial release (1)
- Micro-opto-electro-mechanical Systems (1)
- Miniaturization (1)
Institute
- Fakultät Angewandte Natur- und Kulturwissenschaften (6)
- Sensorik-Applikationszentrum (SappZ) (6)
- Research Center for Artificial Intelligence - RCAI (3)
- Fakultät Maschinenbau (2)
- Fakultät Elektro- und Informationstechnik (1)
- Forschungsstelle für Orthopädie und Ergonomie (1)
- Hochschulleitung/Hochschulverwaltung (1)
- Labor Industrielle Elektronik (1)
- Research Center of Biomedical Engineering - RCBE (1)
- Research Center of Energy and Resources - RCER (1)
Begutachtungsstatus
- peer-reviewed (1)
We describe how to build a homogeneous light source for Surface Plasmon Resonance Imaging (SPRi) which mainly finds its applications in pharmaceutical screening and biotechnology so far. SPR spectroscopy is a label-free, non-destructive and highly sensitive measurement principle for detecting changes in the refractive index in close vicinity of a gold surface. A transfer of this technology to a miniaturized sensor will broaden the range of possible applications. Commercial SPR assays are mainly working with a small number of sensing spots. In contrast, the SPR imaging system shown here will allow the use of an array of many sensing spots. In combination with chemical receptors designed as an artificial nose or an electronic tongue, the simultaneous detection of many analytes is envisioned. So far, lasers or other inhomogeneous light sources were used to illuminate the sensing surface, which is decreasing the systems sensitivity. We show a compact ( 300mm2) homogeneous top hat profile. The combination of a high bit-resolution camera with our new light source enables a reflectivity based surface plasmon resonance imaging system with a high refractive index unit (RIU) resolution.
Forschungsbericht 2016
(2016)
Miniaturisierte Sensoren basierend auf Oberflächenplasmonenresonanz, Chancen und Herausforderungen
(2021)
Derzeit gibt es zahlreiche Bereiche, wie Umwelt Monitoring und zivile Infrastruktur in denen geeignete Sensoren für die Überwachung der Systeme fehlen. SPR-basierte Sensoren haben das Potential diese Lücke zu schließen. Um für den Einsatz in der Umwelt tauglich zu werden, müssen die Sensoren noch robuster werden. Hier wird eine mögliche Lösung gezeigt.
Weakening of the knee ligament complex due to sequential medial release in total knee arthroplasty
(2019)
PurposeThe purpose of this study was to investigate the effects of sequential medial release on the stiffness and collateral stability of the ligament complex of the knee. Irrespective of the implantation technique used, varus deformity frequently requires release of the capsular ligament complex. Yet, no data are available on how stiffness and stability of the knee ligament complex are weakened by such release.MethodsAfter total knee arthroplasty, ten healthy Thiel-fixed knee joints were subjected to sequential medial release consisting of six release steps. After each step, stiffness and stability were determined at 0 degrees, 30 degrees, 60 degrees, and 90 degrees.ResultsSequential medial release increasingly weakened the ligament complex. In extension, release of the anteromedial tibial sleeve 4cm below the joint line already weakened the ligament complex by approximately 13%. Release 6cm below the joint line reduced stiffness and stability by 15-20% over the entire range of motion. After detachment of the medial collateral ligament, stability was only about 60% of its initial value.ConclusionOur study showed for the first time the association between medial release and stiffness and stability of the knee ligament complex. To maintain stability, vigorous detachment of the knee ligament complex should be avoided. Release of the anteromedial tibial sleeve already initiates loss of stability. The main stabiliser is the medial ligament, which should never be completely detached.Level of evidenceIV.
Surface plasmon resonance (SPR) is limited by small-signal detectability and drift when subtraction occurs in software after digitization. We introduce an SPR detector that performs on-detector amplification and analog differential readout, eliminating moving parts and software-heavy correction. The hardware-native subtraction boosts the usable ADC range and suppresses illumination and environmental noise. In fixed-angle refractive-index steps (NaCl), the platform resolves Δn_min ≈ 1.8 × 10⁻⁷ RIU compared to 4.6–7.2 × 10⁻⁶ RIU on a commercial comparator and improves small-signal SNR by up to ∼5,000-fold, while remaining competitive at high signal levels. In a model IgG–BSA assay, the detector’s low noise floor clarifies early binding and equilibrium transitions. By generating inherently clean raw signals, this hardware-native approach dramatically enhances sensitivity and long-term stability for label-free biosensing and inline process analytics while rendering AI-based or complex post-processing entirely unnecessary. The concept generalizes across platforms and opens a compact route to robust, high-fidelity SPR in complex environments, with a clear path toward multi-wavelength and arrayed detectors for high-throughput chemical monitoring.
The analysis of surface water, groundwater, drinking water as well as sewage is important to get information about the contamination of the water cycle. Currently, these time-consuming investigations require special equipment, like for example hyphenated mass spectrometry. Surface plasmon resonance (SPR) is a faster alternative as it is highly sensitive to changes in the dielectric medium next to a thin metal layer and makes it a quasi-universal detector. Therefore, and due to the labelfree nature, SPR is a widely used sensing tool for real‐time monitoring of molecular interactions of various analytes. SPR imaging (SPRi) has several advantages to standard surface plasmon resonance, as it allows to observe many analytes in parallel as well as the integration of referencing technologies. However, the homogenous illumination of a large area (several millimeters) with a small light source is challenging and demands new approaches. Allopurinol, a drug used to lower the blood concentration of urate and hence decrease the affection of gout, gets metabolized to oxipurinol in the body and dropped out almost entirely by urinary excretion. After wastewater treatment, concentrations of oxipurinol up to 21.7 μg•L-1 are detected. Further tracking of oxipurinol in the urban water cycle showed its presence in rivers and streams or even in groundwater. Therefore, the high biological stability of oxipurinol allows this molecule to be used as a marker for domestic wastewater in the environment. For the detection of oxipurinol by SPR graphene was used as receptive layer, as the analyte can bind via π-stacking to this surface. An SPRi technique was developed and compared to conventional SPR system for the detection of oxipurinol.
