High-speed surface profilometry based on an adaptive microscope with axial chromatic encoding

An adaptive microscope with axial chromatic encoding is designed and developed, namely the AdaScope. With the ability to confocally address any locations within the measurement volume, the AdaScope provides the hardware foundation for a cascade measurement strategy to be developed, dramatically accelerating the speed of 3D confocal microscopy

Profilometry with volume holographic imaging

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.Includes bibliographical references (p. 127-133).High resolution, non-contact object profile measurement (profilometry) at long working distance is important in a number of application areas, such as precise parts manufacturing, optical element grounding and polishing, adversary target identification in military, terrace profiling, etc. The Volume Holographic (VH) lens is a novel optical element which process the incident light field in a 3D fashion. It has been shown with promising applications in object profile acquisition and 3D imaging areas. In this thesis, we propose, design and implemented a number of volume holographic computational imaging systems for profilometry related applications. We show that the rich functionalities of the VH lens can be exploited to process the incident optical field. Some of the unique imaging behavior can not be easily achieved by using conventional optics. We first develop the theoretical framework for investigating the VH lens optical behavior. We concentrate on a simple design: using the VH lens as the spatial spectrum plane filter in a 4F imaging system. We derived the point spread function (PSF), the depth resolution, the diffraction field distribution of the proposed imaging system. Experimental system characterization and profilometry measurements were carried out with our setups.(cont.) We find the resolution of the volume holographic imaging (VHI) profilometry system degrades quadratically with the increase of working distance. We addressed this problem by two approaches: 1. We discuss the effect of objective optics design on the VHI resolution. We proposed and implemented the use of appropriately designed telephoto objective optics to achieve very good resolution at long working distance. 2. We developed a maximum likelihood estimation based post-processing method to improve the depth resolution by more than 5 times. An important issue on VHI profilometry is the "slit-shaped" limited field of view (FoV). This makes measurement over the entire big object is very time consuming because scanning is necessary. Otherwise hundreds or thousands of VH lenses must be multiplexed on a single crystal to concatenate the slit FoV of each VH lens to form a wide exit window. However the multiplexing method suffers the "M/#" penalty on photon efficiency. We solved this problem by utilizing the wavelength degeneracy of the VH lens and designed a rainbow illumination VHI to expand the FoV.(cont.) We also extended the application of VHI to hyper-spectral imaging. The experimental implementation of the hyper-spectral imaging system shows it is capable of not only reconstructing the 3D spatial profile but also restoring the spectral information of the object, both at high resolution. Finally, we conclude with some directions for the future work in this emerging field.by Wenyang Sun.Ph.D

Optical Design And Development Of A Micromirror Based High Accuracy Confocal Microscope

Tez (Doktora) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2008Thesis (PhD) -- İstanbul Technical University, Institute of Science and Technology, 2008Bu tez kapsamında yeni bir mikro ayna dizinli optik anahtarların yardımı ile yeni bir tip konfokal mikroskop geliştirilmiştir. Geliştirilen bu yeni ölçme sisteminde mikro ayna dizini ölçülecek yüzey üzerine 1-1 görüntülenmiş ve bu sayede yüzlerce noktanın aynı anda video frekansında ölçülmesi gerçekleştirilmiştir.. 3D yüzeyin elde edilmesi çeşitli yüksekliklerde elde edilen 2D bilgilerinin üst üste getirilmesi ile oluşturulmuştur. Bu çalışma sırasında mikroskobun optik tasarımı ve elde edilen optik sistemin geliştirilme aşamaları bütün detayları ile verilmiş, geliştirilen deneysel düzenek detayları ile tartışılmıştır. Ölçümler sırasında 50x ve 0.95 NA sahip mikroskop objektifi ile yapılan ölçümlerde yatay çözünürlük değeri 1,5 µm olarak ölçülmüştür. Sonuçların bu kadar iyi olmasında kullanılan mikro ayna dizinli elemanın önemli bir rolü olmuştur. Geliştirilen sistemin ölçme kapasitesi farklı ölçme standartları kullanılarak sistemin performans kapasitesi örneklendirilmiştir.During this project a new version of confocal microscope, where transverse surface (x,y) scanning is performed by a digital micromirror device (DMD) is developed. The DMD is imaged onto the object’s surface allowing for confocal surface scanning of the field of view at a rate faster than video rate without physical movement of the sample. 3D surface reconstruction is performed with stacks of 2D image planes acquired at different depths. Optical system design issues, solutions and detailed description of the experimental setup are presented. During experiments by using 100x with 0.95 NA objective 1,5 µm Full width half maximum (FWHM) is obtained. Mainly the optical resolution of the developed system is obtained with the help of DMD unit. The 3D image capabilities of the developed system using DMD unit were demonstrated on various test objects.DoktoraPh

Video-Rate Fluorescence Molecular Tomography for Hand-held and Multimodal Molecular Imaging

In the United States, cancer is the second leading cause of death following heart disease. Although, a variety of treatment regimens are available, cancer management is complicated by the complexity of the disease and the variability, between people, of disease progression and response to therapy. Therefore, advancements in the methods and technologies for cancer diagnosis, prognosis and therapeutic monitoring are critical to improving the treatment of cancer patients. The development of improved imaging methods for early diagnosis of cancer and of near real-time monitoring of tumor response to therapy may improve outcomes as well as the quality of life of cancer patients. In the last decade, imaging methods including ultrasound, computed tomography: CT), magnetic resonance imaging: MRI), single photon emission computed tomography: SPECT), and positron emission tomography: PET), have revolutionized oncology. More recently optical techniques, that have access to unique molecular reporting strategies and functional contrasts, show promise for oncologic imaging This dissertation focuses on the development and optimization of a fiber-based, video-rate fluorescence molecular tomography: FMT) instrument. Concurrent acquisition of fluorescence and reference signals allowed the efficient generation of ratio-metric data for 3D image reconstruction. Accurate depth localization and high sensitivity to fluorescent targets were established to depths of \u3e10 mm. In vivo accumulation of indocyanine green dye was imaged in the region of the sentinel lymph node: SLN) following intradermal injection into the forepaw of rats. These results suggest that video-rate FMT has potential as a clinical tool for noninvasive mapping of SLN. Spatial and temporal co-registration of nuclear and optical images can enable the fusion of the information from these complementary molecular imaging modalities. A critical challenge is in integrating the optical and nuclear imaging hardware. Flexible fiber-based FMT systems provide a viable solution. The various imaging bore sizes of small animal nuclear imaging systems can potentially accommodate the FMT fiber imaging arrays. In addition FMT imaging facilitates co-registering the nuclear and optical contrasts in time. In this dissertation, the feasibility of integrating the fiber-based, video-rate FMT system with a commercial preclinical NanoSPECT/CT platform was established. Feasibility of in vivo imaging is demonstrated by tracking a monomolecular multimodal-imaging agent: MOMIA) during transport from the forepaw to the axillary lymph nodes region of a rat. These co-registered FMT/SPECT/CT imaging results with MOMIAs may facilitate the development of the next generation preclinical and clinical multimodal optical-nuclear platforms for a broad array of imaging applications, and help elucidate the underlying biological processes relevant to cancer diagnosis and therapy monitoring. Finally, I demonstrated that video-rate FMT is sufficiently fast to enable imaging of cardiac, respiratory and pharmacokinetic induced dynamic fluorescent signals. From these measurements, the image-derived input function and the real-time uptake of injected agents can be deduced for pharmacokinetic analysis of fluorescing agents. In a study comparing normal mice against mice liver disease, we developed anatomically guided dynamic FMT in conjunction with tracer kinetic modeling to quantify uptake rates of fluorescing agents. This work establishes fiber-based, video-rate FMT system as a practical and powerful tool that is well suited to a broad array of potential imaging applications, ranging from early disease detection, quantifying physiology and monitoring progression of disease and therapies

Proceedings of the 2019 Joint Workshop of Fraunhofer IOSB and Institute for Anthropomatics, Vision and Fusion Laboratory

In 2019 again, the annual joint workshop of the Fraunhofer IOSB and the Vision and Fusion Laboratory of the Karlsruhe Institute of Technology took place. The doctoral students of both institutions presented extensive reports on the status of their research and discussed topics ranging from computer vision and optical metrology to network security, usage control and machine learning. The results and ideas presented at the workshop are collected in this book in the form of technical reports

Development of lab-on-a-chip devices for automated zebrafish embryo bioassay

Zebrafish embryos have become one of the most popular model systems in biomedical and environmental research. However, current testing protocols using conventional multiwell plates rely heavily on time-consuming and labour-intensive manual handing. Static culture environments and low-throughput data collection are outdated with regards to meet the requirements of modern compound library screening. Herein, this research presents steps towards the development of a miniaturised and automated system for manipulating zebrafish embryos by using both innovative microfluidic lab-on-a-chip technologies and three-dimensional printing technologies. Four steps were taken to achieve this goal: (i) 3D printing technologies were explored to fabricate the lab-on-a-chip device. While 3D printing provided rapid manufacture of devices with high definition and optical transparency, as evidenced by SEM and confocal microscopy results, it caused significant toxicity in fish embryos after long-term exposure. (ii) The toxicity profile of a selection of 3D printing polymers was then extensively investigated using standard biotests. A chemical analysis was performed to reveal the compounds contributing to the toxicity. (iii) To avoid the use of toxic materials, a chip-based embryo trapping array was fabricated using biocompatible material PMMA. The chip allowed for automatic embryo loading, continuous reagent perfusion, and convenient image acquisition. The device was validated using both CFD simulations and biological experiments using reference toxicants. In addition, the embryo chip device was further developed to enable real-time metabolic level detection. (iv) A miniaturised and automated imaging platform, together with the high-throughput embryo trapping array and customised fluidic actuators, were prototyped

Proceedings of the 2019 Joint Workshop of Fraunhofer IOSB and Institute for Anthropomatics, Vision and Fusion Laboratory

In 2019 fand wieder der jährliche Workshop des Fraunhofer IOSB und des Lehrstuhls für Interaktive Echtzeitsysteme des Karlsruher Insitut für Technologie statt. Die Doktoranden beider Institutionen präsentierten den Fortschritt ihrer Forschung in den Themen Maschinelles Lernen, Machine Vision, Messtechnik, Netzwerksicherheit und Usage Control. Die Ideen dieses Workshops sind in diesem Buch gesammelt in der Form technischer Berichte

Cell-instructive biointerfaces with dynamic complexity

The extracellular environment is a highly dynamic milieu where instructive cues (i.e., signals) that originate from the surrounding matrix and neighboring cells are tightly controlled in a spatiotemporally regulated manner. Incorporation of bioinspired dynamic cues, while designing new cell-instructive biointerfaces, has recently been an important focus in biomaterials development for regenerative medicine applications. In this line, progressive developments in materials chemistry as well as introduction of non-covalent chemistries and stimuli-responsive elements in biomaterials design has opened up tremendous opportunities to achieve such highly biomimetic cell-instructive biointerfaces with dynamic regulation of physical, chemical and mechanical cues, to guide desired cell and tissue response. In this thesis, chemical approaches to fabricate dynamic cell-instructive biointerfaces using light-responsive liquid crystal polymer networks (LCNs) and supported lipid bilayers (SLBs) are presented and discussed with an emphasis put on investigating (stem) cell behavior. In the first part of the thesis, temporal control over cell migration upon light-induced in situ changes in nanotopographical cues is achieved on azobenzene conjugated LCNs. This work introduces these materials as new biointerfaces. In the second part of the thesis, central focus is on how to exploit SLBs as dynamic cell-instructive platforms providing control over ligand density, mobility, functionalization route, composition (i.e., type of the peptide ligand) as well as peptide-SLB interactions. On SLBs, functionalized via biotin-neutravidin interactions, ligand (i.e., integrin targeting RGD) density and mobility are shown as important parameters to guide hMSC behavior. Next, using lipid insertion (i.e., using alkyl tail or cholesterol modified (lipidated) RGD ligands) as functionalization route, both lateral (in-plane) and out-of-plane dynamicity of the ligands are controlled. The length of the alkyl tail (i.e., interaction strength of lipidated peptide and SLB) that is conjugated to RGD peptide is shown to be critical to control hMSC adhesion, spreading and focal adhesion formation in these cells on laterally mobile ligands (i.e., in fluid SLBs). Using a dye-conjugated lipid-modified RGD, the dynamic presentation of the peptide is further demonstrated together with the propensity of hMSCs to take up the peptide as well as the dependency of cell migration on the lipid anchor type conjugated on RGD. In the final part, the complexity of the surfaces is tuned by controlling lipid-modified peptide compositions for mimicking cell-matrix and cell-cell junctions in fluid SLBs, to guide endothelial cell behavior. In the epilogue, first steps are explored and discussed that are taken to employ SLBs as cell-instructive interfaces on biomaterials

Thermal, electrical and mechanical properties of three-dimensional functional materials

Colloidal assembly is a dynamic phenomenon where the particulates dispersed in fluids, with the size over tens of nms to several μms, form into specific spatial organization resulting from the variations in the surroundings. The general hard sphere colloids with charged surfaces can be self-assembled into the periodic arrays during the drying process of the fluids. These static periodic arrays, namely, colloidal crystals do not possess any dynamic functionalities, but serve as a sacrificial template for the fabrication of various classes of 3D functional materials. On the other hand, some colloids themselves have their own dynamic functionalities, so that they can be directed-assembled in response to external triggering forces. These particles serve as an active element that offers dynamic changes in the properties of the material systems. The inorganic 3D functional meso/nanostructures were developed for the potential uses in thermal management applications using the self-assembled colloidal crystals as the template. Especially, the Fe3O4 was epitaxially grown through the complex 3D colloidal templates, after which the single crystal Fe3O4 3D porous structures were obtained. These materials have the multiple nanosized 3D interfaces to deter the phonon transport, and at the same time consist of the single crystals to enhance the electron transport. Through various kinds of analysis tools, we thoroughly characterized the materials, particularly focusing on the crystallinity, the density, the thermal conductivity, and the electrical conductivity. The epitaxial Fe3O4 nanoporous structures including the pores with 40 nm in diameter were identified to be thermally insulating and electrically conductive at the same time. The dynamically reconfigurable colloidal assembly in the viscoelastic fluids was investigated with the ultimate goals of the energy harvesting. As the first step, two different methods of integrating the colloids into the viscoelastic media were developed. The PNIPAM colloids, which intrinsically possess the thermo-responsive functionality, were synthesized by two kinds of polymerization routes, and then incorporated into the fibrin networks hydrogels using the method developed. The PNIPAM microgels/fibrin networks hydrogel composites demonstrated the reversibly switchable mechanical property, which is multifold jump in the storage modulus due to the strain-stiffening of fibrin networks, in response to the external temperature changes