@inproceedings{LeiterWohlschlaegerVersen2022, author = {Leiter, Nina and Wohlschl{\"a}ger, Maximilian and Versen, Martin}, title = {Frequency-domain fluorescence lifetime imaging as method to analyze wood structures}, series = {Conference on Lasers and Electro-Optics}, booktitle = {Conference on Lasers and Electro-Optics}, organization = {Technical Digest Series (Optica Publishing Group, 2022)}, doi = {10.1364/CLEO_AT.2022.JW3A.19}, pages = {JW3A.19}, year = {2022}, abstract = {The analysis of wood structures using FD-FLIM seems promising for the identification of wood at 488 nm, as lignin has a high impact on the fluorescence lifetime.}, language = {en} } @inproceedings{ManiyattuGeegyLeiteretal.2022, author = {Maniyattu, Georgekutty Jose and Geegy, Eldho and Leiter, Nina and Wohlschl{\"a}ger, Maximilian and Versen, Martin and Laforsch, Christian}, title = {Development of a neural network to identify plastics using Fluorescence Lifetime Imaging Microscopy}, series = {2022 IEEE Sensors Applications Symposium (SAS)}, booktitle = {2022 IEEE Sensors Applications Symposium (SAS)}, doi = {10.1109/SAS54819.2022.9881372}, pages = {1 -- 6}, year = {2022}, abstract = {Plastics have become a major part of human's daily life. An uncontrolled usage of plastic leads to an accumulation in the environment posing a threat to flora and fauna, if not recycled correctly. The correct sorting and recycling of the most commonly available plastic types and an identification of plastic in the environment are important. Fluorescence lifetime imaging microscopy shows a high potential in sorting and identifying plastic types. A data-based and an image-based classification are investigated using python programming language to demonstrate the potential of a neural network based on fluorescence lifetime images to identify plastic types. The results indicate that the data-based classification has a higher identification accuracy compared to the image-based classification.}, language = {en} } @inproceedings{BernoeckerLeiterWohlschlaegeretal.2022, author = {Bern{\"o}cker, Anton and Leiter, Nina and Wohlschl{\"a}ger, Maximilian and Versen, Martin}, title = {Entwicklung eines neuronalen Netzwerks als Basis zur automatisierten Holzartenerkennung}, series = {18. AALE-Konferenz. Pforzheim, 09.03.-11.03.2022}, booktitle = {18. AALE-Konferenz. Pforzheim, 09.03.-11.03.2022}, organization = {Hochschule f{\"u}r Technik, Wirtschaft und Kultur Leipzig}, doi = {10.33968/2022.11}, year = {2022}, abstract = {Holz ist ein vielseitig einsetzbarer nachwachsender Rohstoff. Neben seinem wirtschaftlichen Nutzen ist er f{\"u}r den Erhalt des Klimas unersetzlich. Eine sortenreine Sortierung f{\"u}r die Weiterverarbeitung von Altholz spielt f{\"u}r einen ressourcenschonenden Umgang eine wichtige Rolle. Um das Potenzial eines neuronalen Netzwerks basierend auf Messdaten der bildgebenden Fluoreszenzabklingzeitmessung f{\"u}r die Altholzsortierung aufzuzeigen, wurden zwei unterschiedliche Klassifikationsans{\"a}tze auf Basis der Programmiersprache Python gew{\"a}hlt. Die Ergebnisse zeigen, dass die bildbasierte Klassifizierung der Holzart mit einer Genauigkeit von 47,36 \% noch ausbauf{\"a}hig ist. Eine datenbasierte Klassifizierung der Holzart mit einer Identifikationsgenauigkeit von 98,28 \% ist dagegen vielversprechend.}, language = {de} } @inproceedings{WohlschlaegerVersenLaforsch2022, author = {Wohlschl{\"a}ger, Maximilian and Versen, Martin and Laforsch, Christian}, title = {Investigation of the Impact of CaCO3 Concentrations on the Fluorescence Lifetime of Polypropylene}, series = {Conference on Lasers and Electro-Optics}, booktitle = {Conference on Lasers and Electro-Optics}, organization = {Technical Digest Series (Optica Publishing Group, 2022)}, doi = {10.1364/CLEO_AT.2022.AM2M.2}, pages = {AM2M.2}, year = {2022}, abstract = {The impact of fillers on the fluorescence lifetime of polymers is still unknown. Investigating polypropylene containing different CaCO3 concentrations using FD-FLIM show an exponential increase in fluorescence lifetime proportional to the CaCO3 density in polypropylene.}, language = {en} } @inproceedings{WohlschlaegerHolstVersenetal.2021, author = {Wohlschl{\"a}ger, Maximilian and Holst, Gerhard and Versen, Martin and Laforsch, Christian}, title = {An optical method to differentiate wood from polymers using fluorescence lifetime imaging microscopy}, series = {OSA Optical Sensors and Sensing Congress 2021 (AIS, FTS, HISE, SENSORS, ES) (2021), paper EW4G.6}, booktitle = {OSA Optical Sensors and Sensing Congress 2021 (AIS, FTS, HISE, SENSORS, ES) (2021), paper EW4G.6}, doi = {10.1364/ES.2021.EW4G.6}, pages = {EW4G.6}, year = {2021}, abstract = {In this contribution investigations with fluorescence lifetime imaging microscopy (FLIM) are made to optically distinguish polymers and wood. The results show that the distinction and identification is possible in a graphical and calculative way.}, language = {en} } @inproceedings{LeiterWohlschlaegerAueretal.2021, author = {Leiter, Nina and Wohlschl{\"a}ger, Maximilian and Auer, Veronika and Versen, Martin and Laforsch, Christian}, title = {An algorithmic method to identify multiple wood species in a single image by their specific fluorescence lifetimes}, series = {OSA Imaging and Applied Optics Congress 2021 (3D, COSI, DH, ISA, pcAOP) (2021), paper CF2B.3}, booktitle = {OSA Imaging and Applied Optics Congress 2021 (3D, COSI, DH, ISA, pcAOP) (2021), paper CF2B.3}, doi = {10.1364/COSI.2021.CF2B.3}, pages = {CF2B.3}, year = {2021}, abstract = {Fluorescence lifetime imaging microscopy (FLIM) combined with an image processing algorithm is successfully used for the optical identification and areal separation of three wood species of maple, larch and nut in a single taken image.}, language = {en} } @article{LeiterWohlschlaegerVersen2023, author = {Leiter, Nina and Wohlschl{\"a}ger, Maximilian and Versen, Martin}, title = {Analysis of the phase-dependent fluorescence decay time of treated wood using FD-FLIM}, series = {tm - Technisches Messen}, volume = {90}, journal = {tm - Technisches Messen}, number = {6}, doi = {10.1515/teme-2022-0114}, pages = {401 -- 406}, year = {2023}, abstract = {For sustainable handling of wood and high material utilization, post-consumer wood has to be sorted by post-consumer wood categories in Germany. The non-destructive FD-FLIM method could improve the wood recycling process by automatic classification of waste wood into post-consumer wood classes. Thus, the phase-dependent fluorescence decay time of treated wood is analysed in this study to obtain the impact of the treatment on the fluorescence decay time. It is shown that treated and untreated wood can be differentiated using the fluorescence decay time, although the state-of-the-art theoretical fluorescence decay time differs from the experimentally determined fluorescence decay time.}, language = {en} } @inproceedings{DietlmeierRajanLeiteretal.2023, author = {Dietlmeier, Maximilian and Rajan, Aromal Somarajan and Leiter, Nina and Wohlschl{\"a}ger, Maximilian and Versen, Martin}, title = {Klassifizierung von Altholz durch FD-FLIM Bilder mit neuronalen Netzen}, series = {Tagungsband AALE 2023}, booktitle = {Tagungsband AALE 2023}, doi = {10.33968/2023.24}, year = {2023}, abstract = {Holz ist eine der wichtigsten erneuerbaren Ressourcen und kann recycelt werden, wobei derzeit nur unbehandeltes Holz in mehreren Lebenszyklen verwendet werden kann. Allerdings werden in Altholzsortieranlagen meist behandeltes und unbehandeltes Altholz gemischt angeliefert und es gibt keine automatische Klassifizierung zur sortenreinen Sortierung. Fr{\"u}here Studien zeigen, dass behandelte und unbehandelte Holzproben mit Hilfe von bildgebender Fluoreszenzabklingzeit Mikroskopie unterschieden werden k{\"o}nnen. Um den Prozess der Klassifizierung von Altholz anhand von Fluoreszenzabklingzeitbildern zu automatisieren, werden zwei neuronale Netzwerke (NN) evaluiert. Das erste NN ist ein MLP (Multi Layer Perceptron), das das Altholz anhand von Erwartungswert und Standardabweichung eines Fluoreszenzabklingzeitbildes klassifiziert. Das zweite untersuchte NN ist ein CNN (Convolutional Neural Network), das das Holz direkt anhand der Fluoreszenzabklingzeitbilder klassifiziert. Beide Netzwerke sind in Python implementiert, um die sp{\"a}tere Verwendung in einem automatischen Klassifizierungs- und Sortierprozess zu erleichtern. Die Evaluation der NN zeigt vielversprechende Ergebnisse zur automatisierten Klassifikation von Altholz.}, language = {de} } @inproceedings{BouwmanHoogenboomFuhrmannetal.2024, author = {Bouwman, Wim and Hoogenboom, Jacob and Fuhrmann, Tina A. and Gelbord, Todd and Hettich, Christian and Sum, J{\"u}rgen and J{\"o}dicke, Bernd and Kautz, Christian and Neff, Julia L. and Krocker, Georg and Oostinga, Jeroen B. and Ruhe, Tim and D{\"u}ser, David and Schneider, Andreas Karl Peter and Suhonen, Sami and Tiili, Juho and Versen, Martin and Kipfelsberger, Stefan and Wendlandt, Michael}, title = {Proceedings of the 12th International Conference on Physics Teaching in Engineering Education PTEE 2024}, editor = {Sch{\"a}fle, Claudia and Stanzel, Silke and Junker, Elmar and Lux, Christine}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:861-opus4-24648}, pages = {110}, year = {2024}, abstract = {The Proceedings of the 12th PTEE conference 2024 in Rosenheim present 15 articles from a wide range of actual topics in physics teaching - from artificial intelligence, innovative teaching and examination methods, lab experiments, tutorials to thoughts on what would be desirable to know, when you start teaching (activating) physics.}, language = {en} } @inproceedings{ThomasSaleemLeiteretal.2023, author = {Thomas, Amal and Saleem, Shaif and Leiter, Nina and Dietlmeier, Maximilian and Wohlschl{\"a}ger, Maximilian and Versen, Martin and Laforsch, Christian}, title = {Development of a Neural Network for an Automated Differentiation of Plastics using Rapid-FLIM}, series = {Optica Sensing Congress 2023}, booktitle = {Optica Sensing Congress 2023}, doi = {10.1364/ES.2023.EW4E.5}, year = {2023}, abstract = {The fast classification and identification of plastics presents a significant challenge. The study assesses the suitability of a Multilayer Perceptron to classify and identify commonly found plastic types using Rapid-FLIM, achieving an accuracy of 88.33\%.}, language = {en} } @article{ManiyattuGeegyWohlschlaegeretal.2023, author = {Maniyattu, Georgekutty Jose and Geegy, Eldho and Wohlschl{\"a}ger, Maximilian and Leiter, Nina and Versen, Martin and Laforsch, Christian}, title = {Multilayer Perceptron Development to Identify Plastics Using Fluorescence Lifetime Imaging Microscopy}, series = {EDFA Technical Articles}, volume = {25}, journal = {EDFA Technical Articles}, number = {3}, doi = {10.31399/asm.edfa.2023-3.p031}, pages = {31 -- 37}, year = {2023}, abstract = {Existing plastic analysis techniques such as Fourier transform infrared spectroscopy and Raman spectroscopy are problematic because samples must be anhydrous and identification can be hindered by additives. This article describes a new approach that has been successfully demonstrated in which plastics can be classified by neural networks that are trained, validated, and tested by frequency domain fluorescence lifetime imaging microscopy measurements.}, language = {en} } @inproceedings{SchwarzWohlschlaegerLeiteretal.2023, author = {Schwarz, Jonas and Wohlschl{\"a}ger, Maximilian and Leiter, Nina and Auer, Veronika and Risse, Michael and Versen, Martin}, title = {Frequency Domain Fluorescence Lifetime Imaging Microscopy (FD-FLIM) analysis of Quercus robur samples for origin differentiation purposes}, series = {Optica Sensing Congress 2023 (AIS, FTS, HISE, Sensors, ES)}, booktitle = {Optica Sensing Congress 2023 (AIS, FTS, HISE, Sensors, ES)}, doi = {10.1364/AIS.2023.JTu4A.10}, year = {2023}, abstract = {Increasing demand for wood products requires methods to determine its harvest origin and ensure sustainable and legal sourcing. In 15 out of 21 cases, the origin of Quercus robur was differentiable in FD-FLIM studies.}, language = {en} } @inproceedings{VersenKipfelsberger2024, author = {Versen, Martin and Kipfelsberger, Stefan}, title = {An Applied Examination Format for Measurement Technologies}, series = {Proceedings of the 12th International Conference on Physics Teaching in Engineering Education PTEE 2024}, booktitle = {Proceedings of the 12th International Conference on Physics Teaching in Engineering Education PTEE 2024}, editor = {Sch{\"a}fle, Claudia and Stanzel, Silke and Junker, Elmar and Lux, Christine}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:861-opus4-25878}, pages = {96 -- 101}, year = {2024}, abstract = {A written exam in measurement technologies usually includes problems for operational amplifier circuits, error propagation, signal analysis and analog to digital conversion. During corona, teaching changed from presence lectures to remote lectures and examination formats changed, too. Instead of a written exam, student project exams were proposed. The projects included a computer aided temperature measurement with operational amplifier circuits, a calibration procedure, error propagation and a written report. The student project exams were successful and the students' feedback was so positive that the student project exams are going to be continued.}, language = {en} } @article{VersenWohlschlaegerLanghalsetal.2024, author = {Versen, Martin and Wohlschl{\"a}ger, Maximilian and Langhals, Heinz and Laforsch, Christian}, title = {The detection of organic polymers as contaminants in foodstuffs by means of the fluorescence decay of their auto fluorescence}, series = {Food and Humanity}, volume = {3}, journal = {Food and Humanity}, doi = {10.1016/j.foohum.2024.100363}, year = {2024}, abstract = {Products such as food can become contaminated during their manufacture or afterwards. Depending on the type of substance causing the contamination, these contaminants can be harmful to health and difficult to detect by visible inspection. The suitability of fluorescence decay and FD-FLIM for the detection of plastics contamination in foodstuffs is demonstrated. Therefore, a procedure for the detection of contaminating organic polymers (plastics) in processed meat such as salami by means of the fluorescence decay time of auto fluorescence is described. The auto fluorescence of processed meat was found to decay according to first order with a typical time constant of about 2 ns, whereas the time constant of significant polymers for the processing of meat is generally appreciably higher (2.5 ns - 5.5 ns depending on the polymer). As a consequence, contaminating organic polymers can not only be globally detected by means of the fluorescence decay but also localised in two-dimensional imaging. The present study reports a high potential of FD-FLIM for rapidly identifying and differentiating different plastics on and in different foodstuffs. The method allows an improved quality control of foodstuffs.}, language = {en} } @misc{HeitzmannKallweitBrunnetal.2025, author = {Heitzmann, Sebastian and Kallweit, Stephan and Brunn, Andr{\´e} and Holst, Gerhard and Leiter, Nina and Wohlschl{\"a}ger, Maximilian and Versen, Martin}, title = {Erweiterung eines FD-FLIM Messsystems durch MQTT Anbindung eines Roboters zur automatischen Sortierung von Altholzklassen}, series = {Tagungsband AALE 2025: Menschenzentrierte Automation im digitalen Zeitalter}, journal = {Tagungsband AALE 2025: Menschenzentrierte Automation im digitalen Zeitalter}, doi = {10.33968/2025.16}, pages = {147 -- 156}, year = {2025}, abstract = {Ziel des Projektes Fluoreszenz ID von Altholz (FrIDAH)5 ist die Entwicklung eines Demonstrators gewesen, welcher die automatisierte Sortierung von Altholzproben gem{\"a}ß der Altholzverordnung unter Verwendung der Messung von Fluoreszenzabklingzeiten erm{\"o}glicht. In diesem Beitrag werden der entwickelte Messaufbau, die Software, das Automatisierungssystem, sowie der Klassifikator vorgestellt. Die Ergebnisse zeigen, dass die verwendete Technologie zur zuverl{\"a}ssigen Klassifikation von Altholz geeignet ist und f{\"u}r die automatisierte Sortierung angewendet werden kann.}, language = {de} } @misc{StegemannMorbitzerPuescheletal.2025, author = {Stegemann, V. and Morbitzer, A. and P{\"u}schel, M. and Heitzmann, S. and Kipfelsberger, S. and Versen, Martin}, title = {Sensorfusion einer KI-gest{\"u}tzten Objekterkennung mit Positionsmessung}, series = {Tagungsband AALE 2025: Menschzentrierte Automation im digitalen Zeitalter}, journal = {Tagungsband AALE 2025: Menschzentrierte Automation im digitalen Zeitalter}, doi = {10.33968/2025.42}, pages = {395 -- 404}, year = {2025}, abstract = {F{\"u}r eine Automatisierungsl{\"o}sung wird ein von k{\"u}nstlicher Intelligenz gest{\"u}tztes System zur Detektion von unterschiedlichen Objekten sowie deren Positionsmessung entwickelt. Die Objekterkennung erfolgt unter Verwendung eines Jetson Nano von Nvidia. Zur Positionsbestimmung auf einem F{\"o}rderband wird ein Inkrementaldrehgeber ROD 420 eingesetzt. Der Positionswert wird mit einem selbst entwickelten Messsystem auf einem Arty A7 Field Programmable Gate Array (FPGA) errechnet und zur Sensorfusion an den Jetson Nano {\"u}bertragen.}, language = {de} }