Nomarski imaging interferometry to measure the displacement field of MEMS

We propose to use a Nomarski imaging interferometer to measure the out-of-plane displacement field of MEMS. It is shown that the measured optical phase arises both from height and slope gradients. Using four integrating buckets a more efficient approach to unwrap the measured phase is presented, thus making the method well suited for highly curved objects. Slope and height effects are then decoupled by expanding the displacement field on a functions basis, and the inverse transformation is applied to get a displacement field from a measure of the optical phase map change with a mechanical loading. A measurement reproducibility of about 10 pm is achieved, and typical results are shown on a microcantilever under thermal actuation, thereby proving the ability of such a set-up to provide a reliable full-field kinematic measurement without surface modification

In vivo imaging of inhibitory, GABAergic neurons by MRI

n/

A systematic review of the relationship between magnetic resonance imaging based resting-state and structural networks in the rodent brain

Recent developments in rodent brain imaging have enabled translational characterization of functional and structural connectivity at the whole brain level in vivo. Nevertheless, fundamental questions about the link between structural and functional networks remain unsolved. In this review, we systematically searched for experimental studies in rodents investigating both structural and functional network measures, including studies correlating functional connectivity using resting-state functional MRI with diffusion tensor imaging or viral tracing data. We aimed to answer whether functional networks reflect the architecture of the structural connectome, how this reciprocal relationship changes throughout a disease, how structural and functional changes relate to each other, and whether changes follow the same timeline. We present the knowledge derived exclusively from studies that included in vivo imaging of functional and structural networks. The limited number of available reports makes it difficult to draw general conclusions besides finding a spatial and temporal decoupling between structural and functional networks during brain disease. Data suggest that when overcoming the currently limited evidence through future studies with combined imaging in various disease models, it will be possible to explore the interaction between both network systems as a disease or recovery biomarker

Community Survey Results Show that Standardisation of Preclinical Imaging Techniques Remains a Challenge

Abstract Purpose To support acquisition of accurate, reproducible and high-quality preclinical imaging data, various standardisation resources have been developed over the years. However, it is unclear the impact of those efforts in current preclinical imaging practices. To better understand the status quo in the field of preclinical imaging standardisation, the STANDARD group of the European Society of Molecular Imaging (ESMI) put together a community survey and a forum for discussion at the European Molecular Imaging Meeting (EMIM) 2022. This paper reports on the results from the STANDARD survey and the forum discussions that took place at EMIM2022. Procedures The survey was delivered to the community by the ESMI office and was promoted through the Society channels, email lists and webpages. The survey contained seven sections organised as generic questions and imaging modality-specific questions. The generic questions focused on issues regarding data acquisition, data processing, data storage, publishing and community awareness of international guidelines for animal research. Specific questions on practices in optical imaging, PET, CT, SPECT, MRI and ultrasound were further included. Results Data from the STANDARD survey showed that 47% of survey participants do not have or do not know if they have QC/QA guidelines at their institutes. Additionally, a large variability exists in the ways data are acquired, processed and reported regarding general aspects as well as modality-specific aspects. Moreover, there is limited awareness of the existence of international guidelines on preclinical (imaging) research practices. Conclusions Standardisation of preclinical imaging techniques remains a challenge and hinders the transformative potential of preclinical imaging to augment biomedical research pipelines by serving as an easy vehicle for translation of research findings to the clinic. Data collected in this project show that there is a need to promote and disseminate already available tools to standardise preclinical imaging practices. </jats:sec

Community survey results show that standardisation of preclinical imaging techniques remains a challenge

PURPOSE: To support acquisition of accurate, reproducible and high-quality preclinical imaging data, various standardisation resources have been developed over the years. However, it is unclear the impact of those efforts in current preclinical imaging practices. To better understand the status quo in the field of preclinical imaging standardisation, the STANDARD group of the European Society of Molecular Imaging (ESMI) put together a community survey and a forum for discussion at the European Molecular Imaging Meeting (EMIM) 2022. This paper reports on the results from the STANDARD survey and the forum discussions that took place at EMIM2022. PROCEDURES: The survey was delivered to the community by the ESMI office and was promoted through the Society channels, email lists and webpages. The survey contained seven sections organised as generic questions and imaging modality-specific questions. The generic questions focused on issues regarding data acquisition, data processing, data storage, publishing and community awareness of international guidelines for animal research. Specific questions on practices in optical imaging, PET, CT, SPECT, MRI and ultrasound were further included. RESULTS: Data from the STANDARD survey showed that 47% of survey participants do not have or do not know if they have QC/QA guidelines at their institutes. Additionally, a large variability exists in the ways data are acquired, processed and reported regarding general aspects as well as modality-specific aspects. Moreover, there is limited awareness of the existence of international guidelines on preclinical (imaging) research practices. CONCLUSIONS: Standardisation of preclinical imaging techniques remains a challenge and hinders the transformative potential of preclinical imaging to augment biomedical research pipelines by serving as an easy vehicle for translation of research findings to the clinic. Data collected in this project show that there is a need to promote and disseminate already available tools to standardise preclinical imaging practices

Long-Wave Infrared Digital Holography

peer reviewe

SYDDARTA: new methodology for digitization of deterioration estimation in paintings

ABSTRACT The SYDDARTA project is an on-going European Commission funded initiative under the 7th Framework Programme. Its main objective is the development of a pre-industrial prototype for diagnosing the deterioration of movable art assets. The device combines two different optical techniques for the acquisition of data. On one hand, hyperspectral imaging is implemented by means of electronically tunable filters. On the other, 3D scanning, using structured light projection and capturing is developed. These techniques are integrated in a single piece of equipment, allowing the recording of two optical information streams. Together with multi-sensor data merging and information processing, estimates of artwork deterioration and degradation can be made. In particular, the resulting system will implement two optical channels (3D scanning and short wave infrared (SWIR) hyperspectral imaging) featuring a structured light projector and electronically tunable spectral separators. The system will work in the VIS-NIR range (400-1000nm), and SWIR range (900-2500nm). It will be also portable and user-friendly. Among all possible art work under consideration, Baroque paintings on canvas and wooden panels were selected as the project case studies

Nachweis der Matrixplastizität von faserverstärktem Aluminium bei thermischer Beanspruchung

In der Arbeit wird ein Konzept entwickelt und umgesetzt zum Nachweis plastischer Verformungsvorgänge in langfaserverstärktem Aluminium bei thermischer Beanspruchung. Ein makroskopisches Werkstoffmodell liefert den Zusammenhang zwischen differentiellem Wärmeausdehnungskoeffizienten und Matrixplastizität. Der Ansatz basiert auf Ergebnissen einer FE-Analyse, die Aussagen zur mikroskopischen Spannungsverteilung im Verbund zulassen. Die experimentelle Verifikation erfolgt mittels interferometrischer Meßtechnik. Ein Meßplatz auf der Grundlage der digitalen Specklemusterinterferometrie entsteht und erlaubt die hochgenaue und zuverlässige Bestimmung differentieller Ausdehnungskoeffizienten. Das hybride Vorgehen, d.h. die Kopplung von Experiment und Theorie, wird an verschiedenen Al-Verbunden C/Al, SiC/Al, Al203/Al-2.5 Prozent Li vorgeführt. Matrixplastizität wird in allen Fällen eindeutig nachgewiesen. Die abschließende Diskussion verdeutlicht deren Auswirkungen für den Werkstoffeinsatz