Acute Angle Repositioning in Mobile C-Arm Using Image Processing and Deep Learning

During surgery, medical practitioners rely on the mobile C-Arm medical x-ray system (C-Arm) and its fluoroscopic functions to not only perform the surgery but also validate the outcome. Currently, technicians reposition the C-Arm arbitrarily through estimation and guesswork. In cases when the positioning and repositioning of the C-Arm are critical for surgical assessment, uncertainties in the angular position of the C-Arm components hinder surgical performance. This thesis proposes an integrated approach to automatically reposition C-Arms during critically acute movements in orthopedic surgery. Robot vision and control with deep learning are used to determine the necessary angles of rotation for desired C-Arm repositioning. More specifically, a convolutional neural network is trained to detect and classify internal bodily structures. Image generation using the fast Fourier transform and Monte Carlo simulation is included to improve the robustness of the training progression of the neural network. Matching control points between a reference x-ray image and a test x-ray image allows for the determination of the projective transformation relating the images. From the projective transformation matrix, the tilt and orbital angles of rotation of the C-Arm are calculated. Key results indicate that the proposed method is successful in repositioning mobile C-Arms to a desired position within 8.9% error for the tilt and 3.5% error for the orbit. As a result, the guesswork entailed in fine C-Arm repositioning is replaced by a better, more refined method. Ultimately, confidence in C-Arm positioning and repositioning is reinforced, and surgical performance with the C-Arm is improved

Investigation of Microfluidic Kelvin Water Dropper and Its Applications in Contact and Contactless Electrowetting

A typical Kelvin water dropper is a device that can convert gravitational potential energy to a high voltage electrostatic. This device consists of two inductors, two collectors, tubes, and electrical connections. A Kelvin water dropper is able to generate extremely high voltage by separating ions using two positive feedback loops. A Kelvin water dropper provides a low cost solution for the applications in which high voltage is needed. In the present research, low cost Microfluidic Kelvin Water Droppers (MKWDs) were developed and built in house for electrowetting applications. Two MKWDs with different tube inner diameters (254 and 508 μm) were constructed to evaluate their appropriate power output for electrowetting. It was demonstrated that higher flow rate led to higher voltage generated, whereas the MKWD with larger tube diameters generated less voltage. Thereafter, contact electrowetting using the homemade MKWD was studied. Electrowetting is a process used to manipulate deformation of liquid droplets on a dielectric surface using an external electric field. In contact electrowetting, the droplet is in contact with a working electrode that applies the voltage. The electric field in the present research was applied using the MKWD. It was demonstrated that contact electrowetting of water droplets can be controlled using the MKWD. Then, a computational model was built to simulate the contact electrowetting using the MKWD. The model was successfully validated by comparing the experimental and simulation results. Finally, contactless electrowetting using the MKWD was investigated. As compared to contact electrowetting, the working electrode was separated from the water droplets. When applying an electric field using the MKWD, it was observed that the water droplet first corrugated due to electrostatic attraction, and then collapsed due to electrowetting. Unlike contact electrowetting, two processes were involved in contactless electrowetting. To simulate two processes, the first model was built based on the theory of electrostatics, and the second model was based on the conventional electrowetting. Both models were validated by a nice agreement between the experimental and simulation data

SYSTEM INTEGRATION OF C-ARM ROBOTIC PROTOTYPE USING MOTION CAPTURE GUIDANCE FOR ACCURATE REPOSITIONING

One of the important surgical tools in spinal surgery is the C-Arm X-ray System. The C-Arm is a large “C” shaped and manually maneuvered arm that provides surgeons and X-ray technicians the ability to take quick quality X-rays during surgery. Because of its five degrees of freedom, the C-Arm can be manually maneuvered around the patient to provide many angles and perspectives, ensuring surgical success. This system works fine for most surgical procedures but falls short when the C-Arm must be moved out of the way for complicated surgical procedures. The aim of this thesis is to develop an accurate repositioning method with the use of motion capture technology. This will be a novel approach to creating a repositioning integrated system. To develop a motion capture repositioning integrated system, a set of research tasks needed to be completed. A virtual prototype and a virtual platform were developed that quantified the dynamics of the C-Arm maneuvering. Next, a complete kinematic model of the C-Arm was developed. Third, a fully automatic robotic C-Arm prototype was designed and manufactured to serve as a replacement for the actual C-Arm. Finally, the robotic prototype, the virtual platform, and the kinematic model were all systematically integrated using Vicon motion capture system to perform the automatic repositioning of the C-Arm. Testing of the newly developed repositioning system was completed with successful results

Practicum of Systems Integration in Engineering Education

This project asked engineering students to develop a multi-subsystem design that would produce electricity. Students over the duration of this project learned how to simulate and design systems theoretically using computer tools. Furthermore, students were expected to produce a prototype of their model, thereby self-analyzing the practicality levels and enhancing learning. With the technology available to students advancing, systems integration techniques become more efficient learning experiences to the students. The benefits of systems integration can also be expanded to the professional world these students will soon step into. Therefore, teaching these techniques now will give students a better further insight on real world experience in a classroom setting. When students make the expected leap into the job market, it is important for them to have a solid understanding of system integration and multi-system design. It is this understanding that will make students more desirable to top end employers and set them apart form their peers.Cockrell School of Engineerin

Estimating Iranian Wheat Market (A Comparative Study between ARDL and SUR)

In this study with estimating the econometric pattern of wheat, the affecting element in supply, product, import and consumption can be recognized. Auto regressive distributed lag (ARDL) and seemingly unrelated regressions (SUR) have been used for getting the following results: Price elasticity of demand for wheat is 2/29 and the cross price elasticity of demand between wheat and barley is 1/49. Production function showed that with increasing the area under harvested with 1 percent, the amount of production will increase 0/68 percent. Fertilizer has direct effect in the amount of production in next year. Results of consumption model show that consumption income element in demand model is a small number with positive sign but it is not meaningful. The results of demand elasticity of bread showed that this factor is 0/156. It means that the demand for bread is not very responsive to changes in price. Although results showed increasing the consumption per capita of rice with 1 percent will decrease the consumption per capita of wheat with 0/23 percent. Import model shows that increasing the amount of gross domestic production with 1 percent will increase the amount of demand with 1/1 percent. In this estimation, the coefficient of the price ratios is positive and is opposite the ordinary cases. It is because of the responsibility of government in importing wheat and this activity doesn’t relate to domestic price and is related to domestic needs

Electrowetting Using a Microfluidic Kelvin Water Dropper

The Kelvin water dropper is an electrostatic generator that can generate high voltage electricity through water dripping. A conventional Kelvin water dropper converts the gravitational potential energy of water into electricity. Due to its low current output, Kelvin water droppers can only be used in limited cases that demand high voltage. In the present study, microfluidic Kelvin water droppers (MKWDs) were built in house to demonstrate a low-cost but accurately controlled miniature device for high voltage generation. The performance of the MKWDs was characterized using different channel diameters and flow rates. The best performed MKWD was then used to conduct experiments of the electrowetting of liquid on dielectric surfaces. Electrowetting is a process that has been widely used in manipulating the wetting properties of a surface using an external electric field. Usually electrowetting requires an expensive DC power supply that outputs high voltage. However, in this research, it was demonstrated that electrowetting can be conducted by simply using an MKWD. Additionally, an analytic model was developed to simulate the electrowetting process. Finally, the model’s ability to well predict the liquid deformation during electrowetting using MKWDs was validated

Mediating Role of Positive Psychological Ownership in the Effect of Human Resource Development Climate on Knowledge Sharing Behavior

Present research has been done in order to investigate the role of positive psychological ownership in the effect of human resource development climate on knowledge sharing behavior. Statistical population consisted of the employees of the Iran Airports and Air Navigation Company which 264 employees were selected from them as a random sample. For measuring human resource development climate, the scale provided by Rao & Abraham was used that determines three dimensions of it as supportive climate of human resource development, human resource development mechanisms, and seven cultural attributes of human resource development. Knowledge sharing was measured by scale provided by Vanden Hoof & VanWinen which has been adjusted by Lin. Also, psychological ownership was measured by VanDyne & Pierce questionnaire. Collected data were analyzed by structural equation modeling. Findings confirmed the favorable fitness of research model and also show that human resource development climate has a positive and significant effect on knowledge sharing behavior and psychological ownership plays the mediating role in this relationship. Therefore, emphasizing on all dimensions of human resource development climate can lead to creation of positive psychological ownership in employees and finally can reinforce positive organizational behaviors such as knowledge sharing behavior