Theses and Dissertations

X-ray phase contrast imaging (XPCI) is a novel imaging method that utilizes phase information of X-rays in order to produce images. XPCI allows for highly resolved features that traditional X-ray imaging modalities cannot discern. The objective of this experiment was to model initial simulations predicting the output signal of the future compact x-ray free electron laser (CXFEL) XPCI source. The signal was reported in tonal values (“counts”), where MATLAB and MATLAB App Designer were the computing environments used to develop the simulations. The experimental setup’s components included a yttrium aluminum garnet (YAG) scintillating screen, mirror, and Mako G-507C camera with a Sony IMX264 sensor. The main function of the setup was to aim the X-rays at the YAG screen, then measure its scintillation through the photons emitted that hit the camera sensor. The resulting quantity used to assess the signal strength was tonal values (“counts”) per pixel on the sensor. Data for X-ray transmission through water, air, and polyimide was sourced from The Center for X-ray Optics’s simulations website, after which the data was interpolated and referenced in MATLAB. Matrices were an integral part of the saturation calculations; field-of-view (FOV), magnification and photon energies were also necessary. All the calculations were compiled into a graphical user interface (GUI) using App Designer. The code used to build this GUI can be used as a template for later, more complex GUIs and is a great starting point for future work in XPCI research at CXFEL.

X-ray phase contrast imaging (XPCI) is a novel imaging method that utilizes phase information of X-rays in order to produce images. XPCI allows for highly resolved features that traditional X-ray imaging modalities cannot discern. The objective of this experiment was to model initial simulations predicting the output signal of the future compact x-ray free electron laser (CXFEL) XPCI source. The signal was reported in tonal values (“counts”), where MATLAB and MATLAB App Designer were the computing environments used to develop the simulations. The experimental setup’s components included a yttrium aluminum garnet (YAG) scintillating screen, mirror, and Mako G-507C camera with a Sony IMX264 sensor. The main function of the setup was to aim the X-rays at the YAG screen, then measure its scintillation through the photons emitted that hit the camera sensor. The resulting quantity used to assess the signal strength was tonal values (“counts”) per pixel on the sensor. Data for X-ray transmission through water, air, and polyimide was sourced from The Center for X-ray Optics’s simulations website, after which the data was interpolated and referenced in MATLAB. Matrices were an integral part of the saturation calculations; field-of-view (FOV), magnification and photon energies were also necessary. All the calculations were compiled into a graphical user interface (GUI) using App Designer. The code used to build this GUI can be used as a template for later, more complex GUIs and is a great starting point for future work in XPCI research at CXFEL.

Falls are known to be a common occurrence and a costly one as well, as they are the second leading cause of unintentional deaths and millions of other injuries worldwide. Falls often occur due to an increase in trunk flexion angle, so this experiment aims to reduce the trunk flexion received while stepping over an obstacle. To achieve this a soft actuator was attached to the trunk and pressure was sent as subjects walked and stepped over an obstacle presented on a treadmill. The pressure is meant to stiffen the back which should in theory reduce the trunk flexion angle and lower the chances of falling. In this experiment, two groups were tested: three participants from a control group (healthy young adults) and three participants from an experimental group (healthy elderly adults). Since elderly adults have the highest fall risk due to overall lack of stability, they are the experimental group and the focus for this experiment. The results from the study showed that elderly adults had a beneficial effect with the soft actuator as there was a noticeable difference in trunk flexion when the device was attached. The experiment also supported prior research that stated that trunk flexion was greater in elderly adults than younger adults. Despite the positive results, further studies should be done to prove that the soft devices influence lowering trunk flexion angle as well as to see if the device has any noticeable effect on younger adults.