Mechanical Design of a Microwave Imaging Device for Breast Cancer Detection in MRI Scanners

This project seeks to develop an updated version of a microwave imaging device for use in conjunction with breast MRI, improving upon existing technology and developing novel concepts for the device. It posits three primary redesign targets for updating the previous system: resizing the system height, making the device more iteration- friendly, and improving the overall manufacturability of the device by replacing custom components with commercially available alternatives. All three of these redesign targets are met in the new design, V2.0. The height is reduced by reducing antenna travel and height, embedding some components, and shortening the tank wall, resulting in 4.65 cm of height savings from the previous version. The hand-machined acrylic plates are replaced by laminated, laser cut acrylic pieces to increase ease of prototyping, meeting the second target. The worm, worm wheel, lead screw, and lead nut are replaced with commercial components to improve manufacturability. To develop the novel components, extensive torque testing is performed to quantify the system torque requirements, yielding a maximum torque expectation of 0.6 N-m. A pneumatic motor is selected with a minimum torque rating of 2 N-m for rated pressure, meeting the minimum safety factor of 2 for the torque specification. A carbon fiber drive shaft and support mechanism are designed to ensure patient safety around the motor and prevent degradation of the images while in the MRI suite. Finally, a patient bed design is presented to house the device, shield the motor, and provide a platform for the patient to lie on. Preliminary testing results indicate that all the redesign targets are met and demonstrate that the gearing system is more robust and that the novel components all have merit for further development and exploration. Ex situ mechanical testing provides a verification that the components are functioning as expected and provides a way to tune the controller outside of the MRI suite. The next step for the project is to perform a phantom trial to ensure that the mechanical system functions in situ as expected, and pending a successful result, moving to a clinical trial with volunteer patients

Neural and Aneural Regions Generated by the Use of Chemical Surface Coatings

The disordered environment found in conventional neural cultures impedes various applications where cell directionality is a key process for functionality. Neurons are highly specialized cells known to be greatly dependent on interactions with their surroundings. Therefore, when chemical cues are incorporated on the surface material, a precise control over neuronal behavior can be achieved. Here, the behavior of SH-SY5Y neurons on a variety of self-assembled monolayers (SAMs) and polymer brushes both in isolation and combination to promote cellular spatial control was determined. APTES and BIBB coatings promoted the highest cell viability, proliferation, metabolic activity, and neuronal maturation, while low cell survival was seen on PKSPMA and PMETAC surfaces. These cell-attractive and repulsive surfaces were combined to generate a binary BIBB-PKSPMA coating, whereby cellular growth was restricted to an exclusive neural region. The utility of these coatings when precisely combined could act as a bioactive/bioinert surface resulting in a biomimetic environment where control over neuronal growth and directionality can be achieved

Monosodium Iodoacetate delays regeneration and inhibits hypertrophy in skeletal muscle cells in vitro

Objective Osteoarthritis (OA) is a musculoskeletal disease which contributes to severe morbidity. The monosodium iodoacetate (MIA) rodent model of OA is now well established, however the effect of MIA on surrounding tissues post injection has not been investigated and as such the impact on phenotypic development is unknown. The aim of this investigation was to examine the impact of MIA incubation on skeletal muscle cells in vitro, to provide an indication as to the potential influence of MIA administration of skeletal muscle in vivo. Methods C2C12 skeletal muscle myotubes were treated with either 4.8μM MIA or 10μM Dexamethasone (DEX, positive atrophic control) up to 72hrs post differentiation and sampled for morphological and mRNA analyses. Results Significant morphological effects (fusion index, number of myotubes and myotube width, p0.05). Conclusions These data indicate a significant impact of both DEX and MIA on regeneration and hypertrophy in vitro and suggest differential activating mechanisms. Future investigations should determine whether skeletal muscle regeneration and hypertrophy is affected in the in vivo rodent model and the potential impact this has on the OA phenotypic outcome

From Concept to Field Tests: Accelerated Development of Multi-AUV Missions Using a High-Fidelity Faster-than-Real-Time Simulator

We designed and validated a novel simulator for efficient development of multi-robot marine missions. To accelerate development of cooperative behaviors, the simulator models the robots' operating conditions with moderately high fidelity and runs significantly faster than real time, including acoustic communications, dynamic environmental data, and high-resolution bathymetry in large worlds. The simulator's ability to exceed a real-time factor (RTF) of 100 has been stress-tested with a robust continuous integration suite and was used to develop a multi-robot field experiment

Search for the electric dipole moment of the electron with thorium monoxide

The electric dipole moment of the electron (eEDM) is a signature of CP-violating physics beyond the Standard Model. We describe an ongoing experiment to measure or set improved limits to the eEDM, using a cold beam of thorium monoxide (ThO) molecules. The metastable $H {}^3\Delta_1$ state in ThO has important advantages for such an experiment. We argue that the statistical uncertainty of an eEDM measurement could be improved by as much as 3 orders of magnitude compared to the current experimental limit, in a first-generation apparatus using a cold ThO beam. We describe our measurements of the $H$ state lifetime and the production of ThO molecules in a beam, which provide crucial data for the eEDM sensitivity estimate. ThO also has ideal properties for the rejection of a number of known systematic errors; these properties and their implications are described.Comment: v2: Equation (11) correcte

A computational atlas of the hippocampal formation using ex vivo, ultra-high resolution MRI: Application to adaptive segmentation of in vivo MRI.

AbstractAutomated analysis of MRI data of the subregions of the hippocampus requires computational atlases built at a higher resolution than those that are typically used in current neuroimaging studies. Here we describe the construction of a statistical atlas of the hippocampal formation at the subregion level using ultra-high resolution, ex vivo MRI. Fifteen autopsy samples were scanned at 0.13mm isotropic resolution (on average) using customized hardware. The images were manually segmented into 13 different hippocampal substructures using a protocol specifically designed for this study; precise delineations were made possible by the extraordinary resolution of the scans. In addition to the subregions, manual annotations for neighboring structures (e.g., amygdala, cortex) were obtained from a separate dataset of in vivo, T1-weighted MRI scans of the whole brain (1mm resolution). The manual labels from the in vivo and ex vivo data were combined into a single computational atlas of the hippocampal formation with a novel atlas building algorithm based on Bayesian inference. The resulting atlas can be used to automatically segment the hippocampal subregions in structural MRI images, using an algorithm that can analyze multimodal data and adapt to variations in MRI contrast due to differences in acquisition hardware or pulse sequences. The applicability of the atlas, which we are releasing as part of FreeSurfer (version 6.0), is demonstrated with experiments on three different publicly available datasets with different types of MRI contrast. The results show that the atlas and companion segmentation method: 1) can segment T1 and T2 images, as well as their combination, 2) replicate findings on mild cognitive impairment based on high-resolution T2 data, and 3) can discriminate between Alzheimer's disease subjects and elderly controls with 88% accuracy in standard resolution (1mm) T1 data, significantly outperforming the atlas in FreeSurfer version 5.3 (86% accuracy) and classification based on whole hippocampal volume (82% accuracy)

Mechanical Faraday effect for orbital angular momentum-carrying beams

When linearly polarised light is transmitted through a spinning window, the plane of polarisation is rotated. This rotation arises through a phase change that is applied to the circularly polarised states corresponding to the spin angular momentum (SAM). Here we show an analogous effect for the orbital angular momentum (OAM), where a differential phase between the positive and negative modes (±ℓ) is observed as a rotation of the transmitted image. For normal materials, this rotation is on the order of a micro radian, but by using a slow-light medium, we show a rotation of a few degrees. We also note that, within the bounds of our experimental parameters, this rotation angle does not exceed the scale of the spatial features in the beam profile

Neural and aneural regions generated by the use of chemical surface coatings

The disordered environment found in conventional neural cultures impedes various applications where cell directionality is a key process for functionality. Neurons are highly specialized cells known to be greatly dependent on interactions with their surroundings. Therefore, when chemical cues are incorporated on the surface material, a precise control over neuronal behavior can be achieved. Here, the behavior of SH-SY5Y neurons on a variety of self-assembled monolayers (SAMs) and polymer brushes both in isolation and combination to promote cellular spatial control was determined. APTES and BIBB coatings promoted the highest cell viability, proliferation, metabolic activity, and neuronal maturation, while low cell survival was seen on PKSPMA and PMETAC surfaces. These cell-attractive and repulsive surfaces were combined to generate a binary BIBB-PKSPMA coating, whereby cellular growth was restricted to an exclusive neural region. The utility of these coatings when precisely combined could act as a bioactive/bioinert surface resulting in a biomimetic environment where control over neuronal growth and directionality can be achieved

In-situ velocity imaging of ultracold atoms using slow--light

The optical response of a moving medium suitably driven into a slow-light propagation regime strongly depends on its velocity. This effect can be used to devise a novel scheme for imaging ultraslow velocity fields. The scheme turns out to be particularly amenable to study in-situ the dynamics of collective and topological excitations of a trapped Bose-Einstein condensate. We illustrate the advantages of using slow-light imaging specifically for sloshing oscillations and bent vortices in a stirred condensate

Measurement of the electron electric dipole moment using YbF molecules

The most sensitive measurements of the electron electric dipole moment d_e have previously been made using heavy atoms. Heavy polar molecules offer a greater sensitivity to d_e because the interaction energy to be measured is typically 10^3 times larger than in a heavy atom. We report the first measurement of this kind, for which we have used the molecule YbF. Together, the large interaction energy and the strong tensor polarizability of the molecule make our experiment essentially free of the systematic errors that currently limit d_e measurements in atoms. Our first result d_e = (- 0.2 \pm 3.2) x 10^-26 e.cm is less sensitive than the best atom measurement, but is limited only by counting statistics and demonstrates the power of the method.Comment: 4 pages, 4 figures. v2. Minor corrections and clarifications made in response to referee comment