A scalable seafloor imaging approach

The objective of this research is to evaluate what is required to make the operation of multiple robots feasible for large scale seafloor imaging campaigns. Three blocking issues were identified; high cost of subsea robots, limited handling efficiency and insufficiently performant localization technology. These are solved by applying, in order:...

Towards the design of an imaging setup using photoconductive antennas

Photoconductive antennas (PCAs) are an interesting candidate for imaging systems due to their relatively low cost and ability to provide a bandwidth of hundreds of GHz. The large bandwidth of PCAs allows for sub-millimeter depth resolution. However, the often-used single-element PCAs are intrinsically limited in the amount of power they can...

Enhanced Filterbanks for THz On-Chip Spectrometers

Terahertz astronomy has been exceptionally unexplored until the last decades due to a technological gap, but exactly at these wavelengths the most distant galaxies appear very bright. Efficient instruments that are capable of spectrometry are essential in understanding the physics of these distant objects. Within the framework of this thesis, an...

Investigating landing and take-off contact dynamics of host-seeking Anopheles coluzzii malaria mosquitoes using frustrated total internal reflection

To avoid detection during a bloodmeal, a mosquito must minimize contact forces during attachment and detachment contact while maintaining sufficient grip to insert their proboscis and feed. Measuring contact mechanics of the mosquito is technically challenging due to the small length and force scales. Because of this, many aspects of blood...

Signal Modelling and Imaging of Low Field MRI

MRI machines are devices that are used to non-invasively obtain images of the internal anatomy and physiological processes of the human body. It is safe to use as the patient is not exposed to any harmful radiation, and there are no known side effects. But such machines that are commercially available are very expensive. Due to this reason, it...

Imaging peat using neutron and X-ray CT

Peat is formed by biochemical processes and the accumulation of the soil depends on the aerobic and anaerobic conditions. The soil covers five to eight percent of the land surface of the earth. For this thesis a peat coming from a site called Markermeeer, which is a lake between the provinces Noord-Holland and Flevoland in the Netherlands, is...

Extended Depth of Field Optical Projection Tomography

A limiting factor with regard to resolution in OPT is the limited depth of field (DoF) due to light detection with a Gaussian beam profile. The further a source in the sample is removed from the centre of rotation in the focal plane, the more distorted the image is in tangential direction due to the limited DoF. The goal of this research is to...

Interferometric Scattering of Light by an Ensemble of Flowing Spherical Particles: A Numerical Study

To study blood-related diseases, measurement methods must be developped to study cardiac and hematological parameters of a patient. Such methods should preferably be non-destructive, in-vivo, cheap, accurate and real-time. Light has great potential to achieve this.<br/>Using e.g. a pulse oximeter, it is possible to measure a patient’s heartbeat....

U-SPECT-BioFluo: An integrated radionuclide, bioluminescence and fluorescence imaging platform

Objectives: Development of a practical and fully integrated SPECT-bioluminescence-fluorescence platform suitable for pre-clinical studies. Methods: An optical imaging (OI) add-on module was developed for integration with a pre-clinical SPECT system (U-SPECT, MILabs, The Netherlands). The optical module consists of a box sliding over the robot...

Imaging of Cracks and Weak Spots in Steel and Aluminium Plate Rolls

Because of several - sometimes extreme - complications caused by cracks and weak spots in a metal industry roll, it is of great importance to detect these defects in time. Measurements on rolls with artificial- and natural defects have been performed. An imaging operator is introduced, which uses the measurement data to depict the correct...

Photoacoustic Imaging by Means of Sparsity Regularization

The intertwine of the optical and acoustic domains by the photoacoustic effect has given rise to the novel technique of photoacoustic imaging. As a relatively new field it faces many challenges from different character on the way to clinical applications. One of these challenges, which deteriorates image quality and sharpness, is noise. The...

Shear Wave Seismic Interferometry for Lithospheric Imaging

Green's function retrieval by seismic interferometry (SI) exists in a variety of forms. Many of the applications of SI allow the creation of new seismic traces by crosscorrelating a wavefield recorded at two separate locations. The sum of this operation over multiple sources results in the creation of a new signal such that one of the recording...

"Seeing is believing" capturing images of an open operation for in the operative note

In the field of colorectal anastomosis the occurrence of anastomotic leakage is a main problem. The risk of colorectal resections lie within the post-operative complication anastomotic leakage, which is very dangerous for the health of the patient. Anastomotic leakage occurs between 2% and 24% of all patients and mortality rates can be as high...

A texture analysis of 3D GPR images

In this thesis, image processing algorithms are applied to 3D GPR images, in order to improve the detection capabilities of a radar system. Detection based on the magnitude of the reflected signals may miss weak targets. On the other hand, an analysis of the texture properties of a target, i.e. the repeating pattern all over the surface, which...