With more young adults requiring total hip arthroplasties the need for bone saving implants becomes more important. The Zimmer Fitmore is a new bone saving implant that utilizes an implantation technique that reduces the damage to the muscle tissue allowing for patients to have a short recovery time as well as a new design that allows it to rest on the medial cortex. There has been anecdotal evidence that this device leads to early revision within six months of implantation due to failures occurring in the medial cortex. The main goal of this study was to computationally model the Zimmer Fitmore and compare it to the ML Taper to see if the failures are due to the design of the implant. The models were created using CT scans of the implants and the same implantation process was simulated for each. Two sizes for the cortical bone thickness, 4mm and 10mm, were used and contrasted with each other. The 10mm cortical thickness model showed that v the strains experienced by the Zimmer Fitmore femur were higher than that of the ML Taper. The 4mm model did not fully complete the simulation, but the results that were obtained showed an increased strain in Gruen zone 7. These results show that the design, not implantation method, could be to blame for the need for early revision when using the Zimmer Fitmore.

The following paper describes a fall detection and activity monitoring system with position detection based on Zigbee transceivers.The main objective is to reduce the time taken for emergency personnel to respond to falls among the elderly. Especially when the victim is unconscious or delirious, position tracking reduces location determination time within a busy hospital or nursing home environment and facilitates immediate treatment. Reduced response times correlate to decreased morbidity and mortality rates. Background is provided on the major wireless network advances currently deployed in a healthcare setting for asset and personnel tracking, etiology of falls, and several methods of detecting falls using sensors and image processing techniques. Data analysis proves that a precise coordinate tracking system was infeasible using the XBee RF module (based on the Zigbee protocol) due to environmental noise, a poor antenna construction and lack of precise signal strength measurements. A primitive scheme with lower resolution and higher reliability associating a single location with each Zigbee transceiver was employed. A pedometer function was added to the project to monitor the user’s daily activity and to potentially serve as a predictor of falls through the interpretation of mobility and gait patterns related to step counts.

Filtration is a technology that is used almost ubiquitously in society from uses raging from filtration of macroparticles from water to pharmaceutical grade filtration products to remove anything larger than a protein. However, with such a wide range of uses, most filtration products have the same issue; membrane clogging (fouling) that prevents continuous use and requires frequent maintenance. This thesis hypothesizes that by applying a direct current (DC) to an insulating array of posts, they will create a foul-less insulative dielectrophoretic filter (iDEP) that does not clog since particles will levitate above the insulating array. This thesis tested an inherited device (legacy device) and found that its design did not perform the desired foul-less filtration operation under the tested conditions. Therefore, using COMSOL simulations, the conditions of testing and improved deign were developed to fruition. These devices were fabricated and tested and found to successfully levitate yeast particles above the foul-less filtration array using a direct current insulative dielectrophoretic (iDEP) filter. Additionally, different post geometries were observed and how they affect the dielectric force on particles. Although a foul-less filter was not successfully developed over the course of this thesis, the groundwork for development of DC iDEP has been set.

MEASURING IMPEDANCE OF TISSUES USING A MICROFABRICATED MICROELECTRODE ARRAY By Ashwini Bhat This thesis looks at the possibility of using impedance spectroscopy for differentiating tissue, using a microelectrode array (MEA). The thesis first discusses the background and the motivation for this thesis. It covers the certain basic concepts of the human skin starting from the top epidermis layer all the way to the deep dermis layers of the skin. Then it discusses different types of skin cancer and how they occur, in humans. It also discusses various microfabrication techniques such as oxidation, wet etching, sputtering and photolithography for the creation of a MEA in order to test the tissue. The microfabricated MEA is then used to measure impedance across cooked and raw chicken at different frequencies in order to see if the two types of tissues can be differentiated using their respective impedances. The data shows that the MEA was not able to successfully differentiate the two types of the tissues. It does however list multiple improvements in the fabrication of the MEA and improvements that could be made to the testing procedures which could possible give greater difference in impedance between the two tissues

It is a known problem that a Spinal Cord Stimulator (SCS) can interact with an Implantable Cardioverter Defibrillator (ICD) when both devices are implanted in the same patient. Interactions between the SCS and ICD can cause inappropriate therapy which can be harmful to the patient. While ICD devices have a distinct narrowband sensing bandwidth, the pulse configurations that current SCS devices deliver were not designed with this frequency region in mind. In this thesis, I recommend a new pulse configuration for SCS devices that will minimize the interaction between the two devices. I produce a theoretical equation for each pulse configuration in the frequency domain using the Laplace transform and present the results in Matlab. I also design my own SCS device to deliver multiple pulse configurations and use it to gather empirical data. The theoretical and empirical results are used to show the extent of the improvement between the new pulse and existing pulse configurations. The results prove that the new pulse configuration will significantly reduce crosstalk within the desired ICD bandwidth. A reduction in crosstalk will decrease the probability that an SCS will interact with a ICD device.

3-D paper-based microfluidic devices (micoPADs) are small and portable devices made out of paper that offer a promising platform for diagnostic applications outside of a laboratory. These devices are easy to use, low cost, require no power source, and capable of detecting multiple targets simultaneously. The work in this thesis demonstrated the ability of a 3-D paper-microfluidic platform to simultaneously detect 5 targets. Rubber cord stock was used in conjunction with an acrylic housing unit to apply pressure along the edge of the channel. The indirect pressure application was successful in promoting vertical fluid flow between layers. Average channel development times were recorded between 110 seconds and 150 seconds. The implementation of the 3-D paper-microfluidic platform as a diagnostic device was validated with a colorimetric glucose assay. In a novel application, reagents were deposited onto the 3-D platform via a glucose reagent pencil created by Martinez et al. A visual signal was observed for the successful detection of glucose at a concentration of 1.2 mM. These results offer promise for future work in combing new reagent deposition techniques with a multi-layer paper-microfluidic platform. Overall, this research made advancements in the design of a paper-microfluidic platform capable of the simultaneous detection of 5 targets.

In this work, a novel microfluidic cell culture platform capable of automated electrical impedance measurements and immunofluorescence and brightfield microscopy was developed for further in-vitro cellular research intended to optimize cell culture conditions. The microfluidic system design, fabrication, automation, and design verification testing are described. Electrical and optical measurements of the 16 parallel cell culture chambers were automated via a custom LabView interface. A proposed design change will enable gas diffusion, removing the need for an environmental enclosure and allow long-term cell culture experiments. This "lab on a chip" system miniaturizes and automates experiments improving testing throughput and accuracy while creating a highly controllable microenvironment for cell culture. Such a system can be applied to drug development, bioassays, diagnostics, and animal testing alternatives. This work is part of a collaborative effort to define protocols for the electrical and optical characterization of cell culture within a novel microfluidic device with the intent of optimizing microenvironment conditions.

This thesis encompasses a feasibility study of using low-cost materials to manufacture microfluidic chips that can perform the same functions as chips manufactured using traditional methods within an acceptable range of efficiency of chips created with more exotic methods and materials. The major parts of the project are the selection and characterization of the fabrication methods for creating the channels for fluid flow, the methods for sealing the channels to create a usable chip and the electrophoretic separations of carboxylated microspheres of different potentials. In this work we seek to answer the question if laser-etched PMMA microfluidic chips are comparable in functionality to microfluidic chips created with PDMS or glass. In the process of answering this question we will touch on FEA modeling, characterization of the manufacturing process and multiple prototype designs while keeping within the low-cost theme. The purpose of capillary electrophoresis is to separate proteins based on their inherent electric charge. Capillary electrophoresis is a standard chip design used in the microfluidics world to prove a new fabrication method or chip material before branching out to other experiments because it is a fairly simple and robust design. Common problems associated with the manufacturing methods and materials were taken into account such as electroosmotic flow and chip sealing. CZE designs from literature were referenced to create a chip that would separate carboxylated microbeads with reasonable resolution. Wire electrodes were affixed to the chip to induce electric fields for the electrophoresis experiments. The goal of this thesis is to prove the manufacturing methods and attain results within 70% of literature standards.

Merlin.net Patient Care Network is a St. Jude Medical product that is used for remote patient management. The basic concept of Merlin.net is to allow the physician to view patient device follow-up information as well as general patient and device information on a web application. The Merlin.net system also interfaces with the patient and will send them notification if they miss a follow-up. All device information will be collected automatically while the patient is sleeping. This information is sent through a telephone line to a Merlin.net server to process a report package and display the collected information on the Merlin.net web application. The Merlin.net verification team ensures that all reports generated by the Merlin.net servers are processed and outputted correctly. There are currently 296 device parameters supported by Merlin.net, and the manual extraction and comparison of the expected parameter values takes several hours for each patient follow-up session. Currently there are 250 patient follow-up sessions used for verification testing. Each new release will continue to create additional patient follow-up sessions. Merlin.net releases are approximately 6 months apart, and each new release adds approximately 30-50 new patient follow-up records to support the new devices. In order to meet aggressive project deadlines, while ensuring that the Merlin.net system is processing and outputting patient follow-up data correctly, it is necessary to come up with an automated process to verify the contents of the processed data is correct. This will save a tremendous amount of time as well as improve on the quality of the verification process by eliminating human error and rework. It is critical for patient safety that the patient device follow-up information is processed and outputted correctly. In this thesis an automated process was developed to verify the correct content of the Merlin.net server generated reports for each patient follow-up session. This process leveraged different tools and scripting languages to achieve automation. TDE (Test Development Environment) tool was used to extract the device parameters from the patient follow-up sessions. The TDE script was written to extracts the desired parameter values from the patient follow-up session and automatically populates parameters in a device parameters spreadsheet. Once all the device parameter values are extracted in the spreadsheet, they are passed through a set of mapping rules, which form the expected values. The mapping rules were implemented as VBA (Visual Basic for Application) macros, one macro for each report. The VBA macros write the expected values back to the spreadsheet to form an “expected values spreadsheet”. The patient follow-up session is then sent to the Merlin.net server to process, which generates a processed patient follow-up session that contains a reports package in .zip format. A perl script was then written to compare the parameter values in the Merlinet.net generated reports with the corresponding expected values from the expected values spreadsheet. The perl script generates a comparison report displaying the discrepancies between the actual and the expected values.

The production and approval process for the various labels used in clinical trials wastes significant time and resources through the need to outsource label production or rely on large reams of pre-cut label stock for each revision throughout the process. An in-house, on-demand label printing and cutting system is a potential remedy to this waste. Previous work by Cheadle et al. resulted in a functional electomechanical prototype of the label cutting aspect of this research, capable of rudimentary linear cuts. In this continued research, emphasis was placed on improved label cutting capabilities and creating PC control software for label design. Cutting operations were enhanced through the development of an algorithm for circular cuts, proportional motor control, and a prototype graphical user interface (GUI) for simple user control. The changes to cutting methods have improved linear cutting precision to an average of 0.00402-in (s = 0.00602-in, n=26) at minimum. The new method for circular cuts has an average precision of 0.04384-in (s = 0.01471-in, n=26). The target precision for cuts is 0.040-in, suggesting that linear cuts are satisfactory, but circular cuts must still be refined. The prototype user interface developed for this research is capable of driving the label cutting system through RS232 communication and exposes all functionality of the system to date. Overall, this research has enhanced the capabilities of the label cutting system significantly, but further work is required to realize a complete label production solution.