Biomedical Devices and Instrumentation Commons^™

Raman Spectroscopic Analysis Of Fingernail Clippings Can Help Differentiate Between Postmenopausal Women Who Have And Have Not Suffered A Fracture, James R. Beattie, Niamh M. Cummins, Clare Caraher, Olive M. O'Driscoll, Aruna T. Bansal, Richard Eastell, Stuart H. Ralston, Michael D. Stone, Gill Pearson, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Raman spectroscopy was applied to nail clippings from 633 postmenopausal British and Irish women, from six clinical sites, of whom 42% had experienced a fragility fracture. The objective was to build a prediction algorithm for fracture using data from four sites (known as the calibration set) and test its performance using data from the other two sites (known as the validation set). Results from the validation set showed that a novel algorithm, combining spectroscopy data with clinical data, provided area under the curve (AUC) of 74% compared to an AUC of 60% from a reduced QFracture score (a clinically accepted …

Localized Immunotherapy Delivery Using Injectable In Situ Forming Chitosan Hydrogel, Seth Washispack

Biomedical Engineering Undergraduate Honors Theses

Cytokine-based cancer immunotherapies stimulate a host’s immune system to fight cancer. In particular, interleukin-12 (IL-12), a potent pro-inflammatory cytokine, has demonstrated the ability to eliminate tumors in a number of preclinical models. Toxicities associated with the systemic delivery of IL-12 have precluded its use in the clinic. We are developing a novel chitosan-based hydrogel to maintain high local concentrations of cytokines, such as IL-12, in the tumor while minimizing its systemic dissemination. This hydrogel was found to form spontaneously within ten seconds of mixing two proprietary components. To increase the usefulness of the hydrogel, an efficient mixing and delivery system …

Intravital Microscopy Of Tumor Oxygenation And Glycolytic Demand, Jesse D. Ivers

Biomedical Engineering Undergraduate Honors Theses

There is growing concern about the over treatment of cancer because treatments are based primarily on tumor anatomy. In this study, we aim to begin the process of addressing that issue by developing an intravital technique for optically analyzing tumor biology. Two traits were identified as having significant importance in the aggression of a tumor, vascular oxygenation (SO2) and glycolytic demand. Dorsal skin flap window chambers were implanted and 4T1 and 67NR cancer cells were injected to provide a tumor model for the development of this intravital quantification technique. This study provides a detailed protocol from instrumentation setup to surgical …

Design Of A 3d-Printed Device For Diffuse Reflectance Spectroscopy Calibration As A Step Towards Clinical Translation, Nontapoth Vongkittiargorn

Biomedical Engineering Undergraduate Honors Theses

The diffusive reflectance and spectroscopic microendoscopy (DRSME) is a multimodal imaging system that harnesses its usefulness from different light sources. One of the modalities, diffuse reflectance spectroscopy (DRS), has been used in our lab to investigate optical properties of epithelial tissues using a broadband white light as the main source. Calibration of DRS is required as it can obtain the maximum intensity and convert it to absolute reflectance. Current manual-adjusted calibration can be lengthy and often lead to inconsistent results. Therefore, a new method of calibration is introduced where additive manufacturing (or 3D printing) technology is fully utilized.

The instrumentation …

Validation Of A Confocal Light Sheet Microscope Using Push Broom Translation For Biomedical Applications, Joshua Hutcheson

Graduate Theses and Dissertations

There exists a need for research of optical methods capable of image cytometry suitable for point-of-care technology. To propose am optical approach with no moving parts for simplification of mechanical components for the further development of the technology to the poin-of-care, a linear sensor with push broom translation method. Push broom translation is a method of moving objects by the sensor for an extended field of view. A polydimethylsiloxane (PDMS) microfluidic chamber with a syringe pump was used to deliver objects by the sensor. The volumetric rate of the pump was correlated to the integration time of the sensor to …

Design Of Exercise Equipment For Wheelchair Users: A Case Study In Accessibility Standards, Kate Craddock Rescsanszky

Honors Scholar Theses

Engineers must consider a number of aspects of every project they work on. Accessibility is one aspect that presents a unique challenge. Rather than being based on absolute material parameters, accessibility is based on how people interact with technology and their built environment. Since 1990, the Americans with Disabilities Act has been the predominant standard in accessibility because of its wide reach and legal mandate. In addition to the ADA, the ASTM and the Institute for Universal Design offer helpful guidelines for designing for accessibility. However, in addition to standards, guidelines, and recommendations, it is important to consult the intended …

Portable High Throughput Digital Microfluidics And On-Chip Bacteria Cultures, Yiyan Li

UNLV Theses, Dissertations, Professional Papers, and Capstones

An intelligent, portable, and high throughput digital microfluidic (DMF) system is developed. Chapter 1 introduces microfluidics and DMF systems. In Chapter 2, a low-cost and high resolution capacitive-to-digital converter integrated circuit is used for droplet position detection. A field-programmable gate array FPGA is used as the integrated logic hub of the system for highly reliable and efficient control of the circuit. In this chapter a fast-fabricating PCB (printed circuit board) substrate microfluidic system is proposed. Smaller actuation threshold voltages than those previously reported are obtained. Droplets (3 µL) are actuated using 200 V, 500 Hz DC pulses. Droplet positions can …

Diffusion Modeling And Device Development For Peritoneal Membrane Oxygenation, Liana Hatoum

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Acute respiratory distress syndrome (ARDS) is a pulmonary disease that causes hypoxemia and respiratory failure. The mortality rate for ARDS ranges between 27% and 45%. Current treatments including mechanical ventilation and extracorporeal membrane oxygenation (ECMO) are often associated with high risk complications including barotrauma, infection, thrombosis, and hemorrhage. Alternative pulmonary support techniques are needed to improve the survival rate of patients suffering from ARDS. Previous studies introducing pure O₂ gas, perfluorocarbons and red blood cells into the intraperitoneal (IP) cavity have reported no effect or only a mild increase in oxygenation. Here we report peritoneal membrane oxygenation (PMO) using …

Design Of Medical Devices For Diagnostics In The Gastrointestinal System, Charles R. Welch

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

This thesis presents the design, controls, and testing of two systems: a novel colonoscope locomotion design for diagnostics, and a biosensor capsule that implants a sensor in the small intestine. Each system requires special design considerations for use in the gastrointestinal system.

Colonoscopy procedures are recommended as a screening for colon cancer and related conditions after the age of 50. The need for an improved colonoscope that reduces the colonoscopy time and patient discomfort is apparent. The semi-autonomous device presented here could likely reduce the colonoscopy procedure time by allowing the physician to focus more on the diagnosis and less …

Under The Needle: Ergonomic Issues With Lethal Injection Protocols, Gabriella Hancock

Human Factors and Applied Psychology Student Conference

The institution of capital punishment represents one of the most contentious issues affecting societies today; and while the practice is only implemented in 58 countries, the controversy affects the world at large as over 60% of the human population lives in nations that condone the death penalty (Hali, 2015). In the United States, people who support capital punishment believe the practice to be an effective crime deterrent for potential criminals and therefore a prospective protective measure for law abiding citizens. Moreover, advocates defend their position by forwarding the argument that executions are ‘humane’; that use of lethal injection ensures that …

Circle Of Willis Model For Transcranial Doppler Ultrasound Training, Conner J. Beyersdorf, Ben Hage, Greg Bashford

UCARE: Research Products

Transcranial Doppler (TCD) ultrasound is a technique involving the use of high frequency transmitters to measure intracranial blood flow. The brain is supplied by blood in an arterial anastomosis called the Circle of Willis. Using TCD ultrasound on the circle is difficult and requires practice and teaching. A functional model of the Circle of Willis could prove to be a valuable teaching tool. Through the use of AutoCAD and 3D printing software, an anatomically accurate model was created and set in gelatin phantom inside of a plastic skull. Milk was pumped through the model with a peristaltic pump to simulate …

The Role Of Poly(Acrylic Acid) In Conventional Glass Polyalkenoate Cements, Adel M.F. Alhalawani, Declan J. Curran, Daniel Boyd, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glass polyalkenoate cements (GPCs) have been used in dentistry for over 40 years. These novel bioactive materials are the result of a reaction between a finely ground glass (base) and a polymer (acid), usually poly (acrylic acid) (PAA), in the presence of water. This article reviews the types of PAA used as reagents (including how they vary by molar mass, molecular weight, concentration, polydispersity and content) and the way that they control the properties of the conventional GPCs (CGPCs) formulated from them. The article also considers the effect of PAA on the clinical performance of CGPCs, including biocompatibility, rheological and …

Structural-Functional Brain Connectivity Underlying Integrative Sensorimotor Function After Stroke, Benjamin Thomas Kalinosky

Dissertations (1934 -)

In this dissertation research project, we demonstrated the relationship between the structural and functional connections across the brain in stroke survivors. We used this information to predict arm function in stroke survivors, suggesting that the tools developed through this research will be useful for prescribing individualized rehabilitation strategies in people after stroke. Current clinical methods for rehabilitating sensorimotor function after stroke are not based on the locus of injury in the brain. Instead, therapies are generalized, treating symptoms such as weakness and spasticity. This results in outcomes that are highly variable, with severity of impairment immediately following stroke as the …

Design And Validation Of A Fall Detection Application For Ios, Connor Lewis Mosley

Master's Theses

Despite significant preventative efforts, falls continue to be a major source of morbidity and mortality among the elderly. Additionally, the fear of falling can be a major obstacle to independent living for otherwise self-sufficient individuals. This fear is significantly heightened in individuals who have sustained a fall and often results in self-imposed restrictions on mobility and exercise, causing weakening in these individuals and further exacerbating the danger. Much time has been spent developing alert systems in an attempt to mitigate these problems. Unfortunately these systems typically involve dedicated monitoring centers and therefore often come with substantial upfront and recurring costs. …

Design And Analysis Of A Lift Assist Walker, Deep P. Shah

Master's Theses

Walkers provided stability to the elderly but cannot assist a person from sitting to standing. The objective of this project is to present the design and analysis of a lift assist walker. This report discusses the design and analysis of a collapsible lift assist walker capable of lifting a patient up to 250 lbs. from seated to standing in under 10 seconds. The designed walker utilized a two stage scissor mechanism with a gas spring assisted embedded linear actuator.

Characterization Of Silica-Based And Borate-Based, Titanium-Containing Bioactive Glasses For Coating Metallic Implants, Omar Rodriguez, Declan J. Curran, Marcello Papini, Lana M. Placek, Anthony W. Wren, Emil H. Schemitsch, Paul Zalzal, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bioactive glasses have found applications in diverse fields, including orthopedics and dentistry, where they have been utilized for the fixation of bone and teeth and as scaffolds for drug delivery. The present work outlines the characterization of two novel titanium-containing glass series, one silica-based and one borate-based. For the silica-based series, titanium is added at the expense of silicon dioxide whereas for the borate-based series, it is added at the expense of boron oxide as confirmed by Energy Dispersive Spectroscopy. Amorphous structures are obtained for silica-based glass at 15 mol% TiO₂ and for borate-based glasses at 0 mol% and …

Effect Of Temporal Onset Of Mechanical Loading On Tendon To Bone Healing, Determined With A Novel In-Vivo Device, Mark E. Stasiak

Dissertations, Theses, and Capstone Projects

Background: Exposure to tensile loading has been shown to maintain tendon/ligament homeostasis, with the tensile modulus of the tissue increasing in response to greater loading frequency, and even decreasing in the absence of load. However after injury or surgical repair the effect of tensile load is controversial, with many studies implicating mechanical loading with impaired healing. It is currently unknown when the tensile loading imparted during rehabilitation exercise, can be safely reintroduced after surgical tendon repair or ligament reconstruction, and at what time point it can most benefit the remodeling process. To investigate the effect of tensile loading protocols on …

Expanded 3d Nanofiber Scaffolds: Cell Penetration, Neovascularization, And Host Response, Jiang Jiang, Zhuoran Li, Hongjun Wang, Yue Wang, Mark A. Carlson, Matthew J. Teusink, Matthew R. Macewan, Linxia Gu, Jingwei Xie

Department of Mechanical and Materials Engineering: Faculty Publications

Herein, a robust method to fabricate expanded nanofiber scaffolds with controlled size and thickness using a customized mold during the modified gas-foaming process is reported. The expansion of nanofiber membranes is also simulated using a computational fluid model. Expanded nanofiber scaffolds implanted subcutaneously in rats show cellular infiltration, whereas non-expanded scaffolds only have surface cellular attachment. Compared to unexpanded nanofiber scaffolds, more CD68+ and CD163+ cells are observed within expanded scaffolds at all tested time points post-implantation. More CCR7+ cells appear within expanded scaffolds at week 8 post-implantation. In addition, new blood vessels are present within the expanded scaffolds at …

Self-Powered Microfluidic Device For Rapid Assay Of Antiplatelet Drugs, Bincy Jose, Peter Mccluskey, Niamh Gilmartin, Martin Somers, Dermot Kenny, Antonio J. Ricco, Nigel Kent, Lourdes Basabe-Desmonts

Articles

We report the development of a microfluidic device for the rapid assay in whole blood of platelet-protein interactions indicative of the efficacy of antiplatelet drugs—e.g., aspirin and Plavix, two of the world’s most widely used drugs—in cardiovascular patients. Because platelet adhesion to surface-confined protein matrices is modulated by fluid shear rates at the blood/protein interface, and because such binding is a better indicator of platelet function than platelet self-aggregation, we designed, fabricated, and characterized the performance of a family of disposable, self-powered microfluidic chips with well-defined flow and interfacial shear rates suitable for small blood volumes (≤ 200 µL). We …

Efficiency Evaluation Of A Magnetically Driven Multiple Disk Centrifugal Blood Pump, Kayla H. Moody

Theses and Dissertations

Heart failure is expected to ail over 8 million people in America by 2030 leaving many in need of cardiac replacement. To accommodate this large volume of people, ventricular assist devices (VADs) are necessary to provide mechanical circulatory support. Current VADs exhibit issues such as thrombosis and hemolysis caused by large local pressure drops and turbulent flow within the pump. Multiple disk centrifugal pumps (MDCPs) use shearing and centrifugal forces to produce laminar flow patterns and eliminate large pressure drops within the pump which greatly reduce risks that are in current VADs. The MDCP has a shaft drive system (SDS) …

A Computational Study Of Curvature In The Outflow Graft Of A Continuous Flow Left Ventricular Assist Device, Laura Patterson

Theses and Dissertations

Left ventricular assist devices (LVADs) are an increasingly utilized therapy for end-stage heart failure. Thrombosis within the graft from the pump to the aorta has been documented, but is poorly researched. This study examines the effect of graft geometry, as measured by radius of curvature, bend angle, and diameter, on thrombogenic flow patterns within the graft for a range of flow conditions. It also examines the effect blood properties, including viscosity and density, on these flow patterns. The results indicated that radius of curvature had a powerful effect on thrombogenic flow patterns. Flowrate and bend angle were also influential. The …

Gallium-Containing Mesoporous Bioactive Glass With Potent Hemostatic Activity And Antibacterial Efficacy, Sara Pourshahrestani, Ehsan Zeimaran, Nahrizul Adib Kadri, Nicola Gargiulo, Shani Samuel, Sangeetha Vasudevaraj Naveen, Tunku Kamarul, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Haemorrhage remains the leading cause of potentially survivable death in both military and civilian populations. Although a large variety of hemostatic agents have been developed, many of them have an inadequate capacity to induce hemostasis and are not effective in killing bacteria. In recent years, mesoporous bioactive glasses (MBGs) were found to be effective in inducing hemostasis. However, the materials may not be considered as ideal hemostats since they do not offer antimicrobial activity. The gallium ion (Ga⁺³) not only exhibits antibacterial properties but also accelerates the blood coagulation cascade. The aim of this study was to develop …

Relating Ion Release And Ph To In Vitro Cell Viability For Gallium-Inclusive Bioactive Glasses, Timothy J. Keenan, L. M. Placek, T. L. Mcginnity, Mark R. Towler, M. M. Hall, A. W. Wren

Chemical and Biochemical Engineering Faculty Research & Creative Works

A bioactive glass (BG) in which Ga was substituted for Zn was formulated to investigate whether the ionic form of Ga can elicit effects similar to gallium nitrate. The ion release and pH of BG extracts were evaluated, as well as the in vitro cytocompatibility of extracts in contact with mouse fibroblasts and human osteoblasts. After incubation times of 1 year, the glass (TGa-1) containing the smaller Ga-addition (8 mol%) released the most sodium (Na) (1420 mg/L), silicon (Si) (221 mg/L), and Ga (1295 mg/L), while the glass (TGa-2) containing the larger Ga-addition (16 mol%), exhibited release levels between TGa-1, …

Reference Point Indentation Of Human Trabecular Bone Treated With Bisphosphonates For Varying Durations, Drew Jones

Theses and Dissertations--Biomedical Engineering

Reference point indentation (RPI), a novel form of micro-indentation, quantifies RPI material parameters which correlate with modulus, yield stress, strength, or toughness. Information linking bisphosphonate treatment length with the material properties of osteoporotic trabecular bone is needed to improve patient treatment. The objectives of this study were to: 1) determine if RPI can be used to successfully evaluate human trabecular bone and if so, determine an optimized test method for using RPI on trabecular bone, and 2) use this method to determine if any RPI parameters are related to the duration of bisphosphonate treatment.

Indentation using a 4 N applied …

Closed-Loop Afferent Nerve Electrical Stimulation For Rehabilitation Of Hand Function In Subjects With Incomplete Spinal Cord Injury, Christopher J. Schildt

Theses and Dissertations--Biomedical Engineering

Peripheral nerve stimulation (PNS) is commonly used to promote use-dependent cortical plasticity for rehabilitation of motor function in spinal cord injury. Pairing transcranial magnetic stimulation (TMS) with PNS has been shown to increase motor evoked potentials most when the two stimuli are timed to arrive in the cortex simultaneously. This suggests that a mechanism of timing-dependent plasticity (TDP) may be a more effective method of promoting motor rehabilitation. The following thesis is the result of applying a brain-computer interface to apply PNS in closed-loop simultaneously to movement intention onset as measured by EEG of the sensorimotor cortex to test whether …

A Software Application For Cardiac-Gated Computerized Tomography Scanning, Stephen Caldwell, Trevor Engelsman

Williams Honors College, Honors Research Projects

Computerized tomography (CT) scans are a common clinical imaging procedure used worldwide. Operating in the X-Ray spectrum, these machines rotate scanners around a stationary body in order to compile two-dimensional images into a unified three-dimensional image. With adjustment to scan frequency and intensity, internal features such as muscles, organs, and tendons can easily be viewed. However, the heart has long evaded CT use due to its near-constant motion. Recently, cardiac-gated scans have entered the market as a technique to image the heart at a specific moment in time when it is nearly still - the quiescent period. Occurring during rapid …

A New Technique To Improve The Operation Of Prosthetic Limbs During Muscle Fatigue, H. Albunashee, G. Rasool, K. Iqbal, G. White

Journal of the Arkansas Academy of Science

Prosthetic limbs hold a promise to renew the quality of life for the amputee. Neural commands are decoded via a classifier to generate control signals for the prosthetic devices. In the literature, many challenges and limitations have been identified that affect the prosthesis operation. One such drawback is muscle fatigue which degrades the surface electromyogram (sEMG) signals, and consequently, the performance of the deployed classification algorithm declines from 90% to 50% of average accuracy. We used a new technique using the Linear Discrimination Analysis (LDA) algorithm and the muscle synergy-based task discrimination (MSD) algorithm to improve the classification accuracy. In …

Antibacterial Properties Of Poly (Octanediol Citrate)/Gallium-Containing Bioglass Composite Scaffolds, Ehsan Zeimaran, Sara Pourshahrestani, Ivan Djordjevic, Belinda Pingguan-Murphy, Nahrizul Adib Kadri, Anthony W. Wren, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bioactive glasses may function as antimicrobial delivery systems through the incorporation and subsequent release of therapeutic ions. The aim of this study was to evaluate the antimicrobial properties of a series of composite scaffolds composed of poly (octanediol citrate) with increased loads of a bioactive glass that releases zinc (Zn²⁺) and gallium (Ga³⁺) ions in a controlled manner. The antibacterial activity of these scaffolds was investigated against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The ability of the scaffolds to release ions and the subsequent ingress of these ions into hard tissue was evaluated …

Inorganic Hemostats: The State-Of-The-Art And Recent Advances, Sara Pourshahrestani, Ehsan Zeimaran, Ivan Djordjevic, Nahrizul Adib Kadri, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Hemorrhage is the most common cause of death both in hospitals and on the battlefield. The need for an effective hemostatic agent remains, since all injuries are not amenable to tourniquet use. There are many topical hemostatic agents and dressings available to control severe bleeding. This article reviews the most commonly used inorganic hemostats, subcategorized as zeolite and clay-based hemostats. Their hemostatic functions as well as their structural properties that are believed to induce hemostasis are discussed. The most important findings from in vitro and in vivo experiments are also covered.

A Microfluidic-Based Tactile Sensor For Palpating Mice Tumor Tissues, Yichao Yang, Garett Johnson, Dean Krusienski, Siqi Guo, Cheng Lin, Zhili Hao

Mechanical & Aerospace Engineering Faculty Publications

In light of the need of tissue palpation for Robotics-assisted Minimally Invasive Surgery (RMIS), this paper presents a microfluidic-based tactile sensor for palpating mice tissues for tumor localization. The core of the sensor is a 3x3 sensing-plate/transducer array built into a single polydimethylsiloxane (PDMS) microstructure, with a transducer spacing of 3.75mmx1.5mm. Mounted on a robot, the sensor is pressed against a tissue region with a pre-defined indentation depth pattern, and consequently the stiffness distribution across the tissue region translates to the deflection distribution of the sensing-plate array and is captured by the transducer array underneath as resistance changes. Thus, the …