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Articles 31 - 36 of 36

Full-Text Articles in Biomedical Devices and Instrumentation

Mechanical Reliability Of Implantable Polyimide-Based Magnetic Microactuators For Biofouling Removal, Christian G. Figueroa-Espada, Qi Yang, Hyowon Lee Aug 2016

Mechanical Reliability Of Implantable Polyimide-Based Magnetic Microactuators For Biofouling Removal, Christian G. Figueroa-Espada, Qi Yang, Hyowon Lee

The Summer Undergraduate Research Fellowship (SURF) Symposium

Hydrocephalus is a neurological disorder that typically requires a long-term implantation of a shunt system to manage its symptoms. These shunt systems are notorious for their extremely high failure rate. More than 40% of all implanted shunt systems fail within the first year of implantation. On average, 85% of all hydrocephalus patients with shunt systems undergo at least two shunt-revision surgeries within 10 years of implantation. A large portion of this high failure rate can be attributed to biofouling-related obstructions and infections. Previously, we developed flexible polyimide-based magnetic microactuators to remove obstructions formed on hydrocephalus shunts. To test the long-term …


Implantable Device For Wireless Regulation Of The Bladder Through Pelvic Nerve Stimulation, Kelsey C. Bayer, Chris Quinkert, Pedro Irazoqui Aug 2015

Implantable Device For Wireless Regulation Of The Bladder Through Pelvic Nerve Stimulation, Kelsey C. Bayer, Chris Quinkert, Pedro Irazoqui

The Summer Undergraduate Research Fellowship (SURF) Symposium

Urinary incontinence (UI) is the involuntarily urination that usually effects older people or is the result of an injury. UI affects more than eleven million people and the cost of incontinence management in the United States in 2000 was $19.5 billion. Where conventional physical therapies have failed, pelvic nerve stimulation is a promising form of regulating the bladder long term. Piezoresistive pressure sensors consist of two variable resistance values and two known resistance values that are represented on a daughterboard. This unknown resistance represents the change in pressure. The filling and voiding of the bladder was characterized through acute surgeries. …


Design And Development Of Two Component Hydrogel Ejector For Three-Dimensional Cell Growth, Thomas Dunkle, Jessica Deschamps, Connie Dam May 2015

Design And Development Of Two Component Hydrogel Ejector For Three-Dimensional Cell Growth, Thomas Dunkle, Jessica Deschamps, Connie Dam

Honors Scholar Theses

Hydrogels are useful in wound healing, drug delivery, and tissue engineering applications, but the available methods of injecting them quickly and noninvasively are limited. The medical industry does not yet have access to an all-purpose device that can quickly synthesize hydrogels of different shapes and sizes. Many synthesis procedures that have been developed result in the formation of amorphous hydrogels. While generally useful, amorphous hydrogels exhibit limited capability in tissue engineering applications, especially due to their viscous properties. This endeavor aims to modulate the appropriate gelation parameters, optimize the injection process, and create a prototype that allows for the extrusion …


Implementation And Validation Of Aortic Remodeling In Hypertensive Rats, Shijia Zhao, Linxia Gu Sep 2014

Implementation And Validation Of Aortic Remodeling In Hypertensive Rats, Shijia Zhao, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

A computational framework was implemented and validated to better understand the hypertensive artery remodeling in both geometric dimensions and material properties. Integrating the stress-modulated remodeling equations into commercial finite element codes allows a better control and visualization of local mechanical parameters. Both arterial thickening and stiffening effects were captured and visualized. An adaptive material remodeling strategy combined with the element birth and death techniques for the geometrical growth were implemented. The numerically predicted remodeling results in terms of the wall thickness, inner diameter, and the ratio of elastin to collagen content of the artery were compared with and fine-tuned by …


Development Of A Multi-Purpose Automated Synthesis Module For Production Of Novel Pet Radiopharmaceuticals, I Hong Shih May 2014

Development Of A Multi-Purpose Automated Synthesis Module For Production Of Novel Pet Radiopharmaceuticals, I Hong Shih

Dissertations and Theses (Open Access)

Among radiopharmaceuticals of positron emission tomography (PET), 18F-Fluorodeoxyglucose (18F-FDG) made from commercialized automated synthesis module is the most frequently used in tumor diagnoses. But the false positive findings, such as infectious tissues and post-operative surgical conditions, show strong uptake of 18F-FDG in PET scans which requires extra clinical procedures to confirm the results. Moreover, the false negative findings, such as low glycolytic activity tumors, reduce the accuracy of PET scans. Therefore, there will be new PET radiopharmaceuticals to redeem the defects of 18FDG-PET applications.

Current commercialized automated synthesis modules are suitable for clinical use, but …


Closed Loop Control Of A Cylindrical Tube Type Ionic Polymer Metal Composite (Ipmc), Benjamin Mead May 2013

Closed Loop Control Of A Cylindrical Tube Type Ionic Polymer Metal Composite (Ipmc), Benjamin Mead

UNLV Theses, Dissertations, Professional Papers, and Capstones

The goal of this research is to provide a framework for the integration of tube type, cylindrical Ionic Polymer Metal-Composite (IPMC) into conventional devices. IPMCs are one of the most widely used types of electro-active polymer actuator, due to their low electric driving potential and large deformation range. For this research a tube type IPMC was investigated. This IPMC has a circular cross section with four separate electrodes on its surface and a hole through the middle. The four electrodes allow for biaxial bending and accurate control of the tip location. One of the main advantages of using this type …