Biomedical Devices and Instrumentation Commons^™

Design, Fabrication, And Implementation Of A Single-Cell Capture Chamber For A Microfluidic Impedance Sensor, Joshua-Jed Doria Fadriquela

Master's Theses

A microfluidic device was created for single-cell capture and analysis using polydimethylsiloxane (PDMS) channels and a glass substrate to develop a microfluidic single-cell impedance sensor for cell diagnostics. The device was fabricated using photolithography to create a master mold which in turn will use soft lithography to create the PDMS components for constant device production. The commercial software, COMSOLTM Multiphysics, was used to quantify the fluid dynamics in shallow micro-channels.

The device will be able to capture a cell and sequester it long enough to enable measurement of the impedance spectra that can characterize cell. The proposed device will be …

Implementation Of Physiologic Flow Conditions In A Blood Vessel Mimic Bioreactor System For The Evaluation Of Intravascular Devices, Marc Cody Dawson

Master's Theses

The prevalence and devastating nature of cardiovascular diseases has led to many advancements in the therapies used to treat the millions of patients that suffer as a result of these conditions. As coronary artery disease (CAD) is the most common of these cardiovascular conditions, it is a major focus of research among the medical industry. Although lifestyle changes and drug therapies can treat early CAD, more advanced cases often require more definitive interventions. In conjunction with angioplasty, stenting of an occluded vessel has shown significant success in preventing restenosis. However, as with nearly every therapeutic process in the medical field, …

Magnetic Sensors For Biodetection, Pranjali Vineet Sneha Deshpande

UNLV Theses, Dissertations, Professional Papers, and Capstones

The objective of thesis is to design magnetic sensor for detection of nanoparticles. Recently integrating the standard laboratory techniques into integrated system on chip is growing attention. Recent development is to combine magnetic markers and magnetoresistive sensors together in magnetic chip. In this thesis two magnetoresistive sensors were studied and designed.

By applying magnetic fields, magnetic nanoparticles can be manipulated on-chip, which can be utilized to pull the molecules to specific binding sites or to test the binding strength and distinguish between specifically and non-specifically bound molecules

Magnetoresistive sensors are compatible with the semiconductor industry which provides electronic signal directly …

Biofilm Inhibitory Coatings Formulated From Glass Polyalkenoate Cement Chemistry: An Evaluation Of Their Adhesive Nature, A. Coughlan, D. Boyd, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Researchers evaluated the adhesive nature of the biofilm inhibitory coatings formulated from glass polyalkenoate cement (GPC) chemistry with the aim to establish the novel testing modality by modifying the conventional T-peel tests. Special consideration was given to determine the resistance of a bonded assembly of two adherents having at least one adherent flexible to quantify the bond between tape and a surgical metal substrate bonded by a luting GPC. The delaminated tape surface was examined by scanning electron microscopy (SEM) with an accelerating voltage of 20 K V to determine whether failure of the bond was adhesive of cohesive in …

A Model For Electrical Communication Between Cochlear Implants And The Brain, Douglas A. Miller

Electronic Theses and Dissertations

In the last thirty years, cochlear implants have become an invaluable instrument in the treatment of severe-to-profound hearing impairment. An important aspect of research in the continued development of cochlear implants is the in vivo assessment of signal processing algorithms intended to improve perception of speech and other auditory signals. In trying to determine how closely cochlear implant recipients process sound relative to the processing done by a normal auditory system, various assessment techniques have been applied. The most common technique has been measurement of auditory evoked potentials (AEPs), which involves the recording of neural responses to auditory stimulation. Depending …

Antibacterial Properties Of A Tri-Sodium Citrate Modified Glass Polyalkenoate Cement, A. W. Wren, D. Boyd, R. Thornton, J. C. Cooney, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Primary deep infection following joint replacement surgery accounts for 7% of all revisions. Glass polyalkenoate cements (GPCs) have previously been shown to exhibit antibacterial properties. The present study had two objectives. The first was to determine if addition of tri-sodium citrate (TSC) to the powder phase of an Al-free GPC (0.04 SrO-0.12 CaO-0.36 ZnO-0.48 SiO2, by mole fraction) enhanced the resultant cement's antibacterial properties against three strains of bacteria that are commonly found in periprosthetic sites following total joint replacements (TJRs); namely, E. coli, B. fragilis, and S. epidermidis. Four cement sets were prepared, which contained 0 wt% TSC (control), …

A Mobile Ecg Monitoring System With Context Collection, Jin Peng Li, Damon Berry, Richard Hayes

Conference Papers

Preventative health management represents a shift from the traditional approach of reactive treatment-based healthcare towards a proactive wellness-management approach where patients are encouraged to stay healthy with expert support when they need it, at any location and any time. This work represents a step along the road towards proactive, preventative healthcare for cardiac patients. It seeks to develop a smart mobile ECG monitoring system that requests and records context information about what is happening around the subject when an arrhythmia event occurs. Context information about the subject’s activities of daily living will, it is hoped, provide an enriched data set …

Preliminary Investigation Of Novel Bone Graft Substitutes Based On Strontium-Calcium-Zinc-Silicate Glasses, D. Boyd, G. Carroll, Mark R. Towler, C. Freeman, P. Farthing, I. M. Brook

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bone graft procedures typically require surgeons to harvest bone from a second site on a given patient (Autograft) before repairing a bone defect. However, this results in increased surgical time, excessive blood loss and a significant increase in pain. In this context a synthetic bone graft with excellent histocompatibility, built in antibacterial efficacy and the ability to regenerate healthy tissue in place of diseased tissue would be a significant step forward relative to current state of the art philosophies. We developed a range of calcium-strontium-zinc-silicate glass-based bone grafts and characterized their structure and physical properties, then evaluated their in vitro …

Antibacterial Coatings For Medical Devices Based On Glass Polyalkenoate Cement Chemistry, A. Coughlan, D. Boyd, C. W.I. Douglas, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

A biofilm is an accumulation of micro-organisms and their extracellular products forming a structured community on a surface. Biofilm formation on medical devices has severe health consequences as bacteria growing in this lifestyle are tolerant to both host defense mechanisms and antibiotic therapies. However, silver and zinc ions inhibit the attachment and proliferation of immature biofilms. The objective of this study is to evaluate whether it is possible to produce silver and zinc-containing glass polyalkenoate cement (GPC) coatings for medical devices that have antibacterial activity and which may therefore inhibit biofilm formation on a material surface. Two silver and zinc-containing …

Accelerometer Based Measurement Of Body Movement For Communication, Play, And Creative Expression, Mark Nolan, Edward Burke, Frank Duignan

Conference Papers

This paper presents a newly designed wireless accelerometer-based movement measurement device. The device is capable of measuring activity ranging from gross body movements to more subtle vibrations emanating from the body, including laryngeal vibration and the mechanomyogram (mechanical vibrations from working muscles). The main body of the device, which is less than 20cm3 in volume and weighs less than 50g, contains a microcontroller, wireless transceiver, battery, and one accelerometer. A supplementary accelerometer module is connected to the main device by thin wires. This module is very light weight and can therefore be directly attached to the skin to measure laryngeal …

An Engineering Evaluation Of Ankle Prosthetics, Christopher Thian, Stephen Tiernan, Fiona Mcevoy, Robert Flavin

Conference Papers

There are a wide range of different types of ankle replacements on the market today each with a
different mechanical design. Unfortunately the results of ankle replacements are not as good as hip
and knee replacements; this is due to the complexity of the ankle joint. In the early days of ankle
replacements some of the prosthetics only lasted 4 months. Recent developments have improved the
longevity of the replacements although, there are still many complications and failures of the
replacements, these include; the prosthetic components migrating into the bone, the components
failing due to stresses induced by the forces …

Force Measurement Methods In Telerobotic Surgery: Implications For End-Effector Manufacture, Dean Callaghan, Mark Mcgrath, Eugene Coyle

Articles

Haptic feedback in telesurgical applications refers to the relaying of position and force information from a remote surgical site to the surgeon in real-time during a surgical procedure. This feedback, coupled with visual information via microscopic cameras, has the potential to provide the surgeon with additional ‘feel’ for the manipulations being performed at the instrument-biological tissue interface. This increased sensitivity has many associated benefits which include, but are not limited to; minimal tissue damage, reduced recuperation periods, and less patient trauma. The inclusion of haptic feedback leads to reduction in surgeon fatigue which contributes to enhanced performance during operation. Commercially …

A Force Measurement Evaluation Tool For Telerobotic Cutting Applications: Development Of An Effective Characterization Platform, Dean Callaghan, Mark Mcgrath, Eugene Coyle

Articles

Sensorized instruments that accurately measure the interaction forces (between biological tissue and instrument endeffector) during surgical procedures offer surgeons a greater sense of immersion during minimally invasive robotic surgery. Although there is ongoing research into force measurement involving surgical graspers little corresponding effort has been carried out on the measurement of forces between scissor blades and tissue. This paper presents the design and development of a force measurement test apparatus, which will serve as a sensor characterization and evaluation platform. The primary aim of the experiments is to ascertain whether the system can differentiate between tissue samples with differing mechanical …

An Analysis Of The Performance Of Foams Used In Hurling Helmets, Keith Norris, Stephen Tiernan

Conference Papers

Abstract Head injuries can occur in most sporting activities. The seriousness of these injuries can vary greatly depending on the sport. Many sports such as American football, cricket, baseball and hurling try to reduce this risk by designing helmets that are suitable to be worn by the players. The National Standard Authority of Ireland (NSAI) has recently made great strides in this area with the introduction of the first comprehensive standard adopted for the sport I.S. 355:2006, which sets out new testing procedures that all new helmets must meet. The Gaelic Athletic Association (GAA) has also stated its intention to …

The Processing, Mechanical Properties And Bioactivity Of Strontium Based Glass Polyalkenoate Cements, Anthony Wren, Daniel Boyd, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The suitability of zinc-based glass polyalkenoate cements (GPCs) for use in orthopaedics can be improved by the substitution of strontium into the glass phase which should impart improved radiopacity and bone forming properties to the cements without retarding strength. The purpose of this research was to produce novel GPCs based on calcium-strontium-zinc-silicate glasses and to evaluate their mechanical properties and biocompatibility with the ultimate objective of developing a new range of cements for skeletal applications. Three glass compositions, based on incremental substitutions of strontium for calcium, were synthesized; BT100 (0.16CaO, 0.36ZnO, 0.48SiO₂), BT101 (0.04SrO, 0.12CaO, 0.36ZnO, 0.48SiO_{2 …}

Comparison Of An Experimental Bone Cement With Surgical Simplex® P, Spineplex® And Cortoss®, D. Boyd, Mark R. Towler, A. Wren, O. M. Clarkin

Chemical and Biochemical Engineering Faculty Research & Creative Works

Conventional polymethylmethacrylate (PMMA) cements and more recently Bisphenol-a-glycidyl dimethacrylate (BIS-GMA) composite cements are employed in procedures such as vertebroplasty. Unfortunately, such materials have inherent drawbacks including, a high curing exotherm, the incorporation of toxic components in their formulations, and critically, exhibit a modulus mismatch between cement and bone. The literature suggests that aluminum free, zinc-based glass polyalkenoate cements (Zn-GPC) may be suitable alternative materials for consideration in such applications as vertebroplasty. This paper examines one formulation of Zn-GPC and compares its strengths, modulus, and biocompatibility with three commercially available bone cements, Spineplex®, Simplex® P and Cortoss®. The setting times indicate …

Force Measurement And Evaluation For Surgical Cutting Applications: Development Of An Effective Characterisation Testbed, Dean Callaghan

Conference Papers

Sensorized instruments that cater for accurate measurement of the interaction forces (between biological tissue and instrument end-effector) during surgical procedures offer surgeons a greater sense of immersion during minimally invasive robotic surgery (MIRS). There is much ongoing research into force measurement/evaluation involving surgical graspers. However, comparatively little corresponding effort has been expended in the measurement and subsequent evaluation of forces between scissor blades and tissue. This paper presents the design and development of a force/strain measurement test apparatus, which will ultimately serve as an effective sensor characterisation and evaluation platform. Data acquired from the testing platform can be used to …

The Role Of Sr²⁺ On The Structure And Reactivity Of Sro-Cao-Zno-Sio2 Ionomer Glasses, Daniel Boyd, Mark R. Towler, Sally Watts, Robert G. Hill, Anthony W. Wren, Owen M. Clarkin

Chemical and Biochemical Engineering Faculty Research & Creative Works

The suitability of Glass Polyalkenoate Cements (GPCs) for use in orthopaedics is retarded by the presence in the glass phase of aluminum, a neurotoxin. Unfortunately, the aluminum ion plays an integral role in the setting process of GPCs and its absence is likely to hinder cement formation. However, the authors have previously shown that aluminum free GPCs may be formulated based on calcium zinc silicate glasses and these novel materials exhibit significant potential as hard tissue biomaterials. To further improve their potential and given that Strontium (Sr) based drugs have had success in the treatment of osteoporosis, the authors have …

Tem Analysis Of Apatite Surface Layers Observed On Zinc Based Glass Polyalkenoate Cements, D. Boyd, Mark R. Towler, A. W. Wren, O. M. Clarkin, D. A. Tanner

Chemical and Biochemical Engineering Faculty Research & Creative Works

The amorphous nature and composition of the surface apatite layers observed on glass polyalkenoate cements based on zinc silicate glasses (Zn-GPCs) after immersion in simulated body fluid (SBF) have been analyzed by the transmission electron microscopy (TEM). TEM was conducted using a JEOL JEM-2011 electron microscope operated at an accelerating voltage of 200 kV. The composition elements of the surface layer indicated the presence of calcium, phosphorous, zinc, and strontium within the amorphous structure. This composition, in particular the inclusion of Zn in the structure, indicates the lack of crystallinity associated with the formation of the apatite layers observed on …

Orthogonal Cutting Of Bone, Donal Mccrohan

Theses

The cutting of bone has been undertaken for many centuries. Research in this area is contnually progressing to achieve an efficient cutting action while reducing recovery time and rauma to the patient.

Orthogonal cutting is defined where the cutting edge of the tool is set in a position that is perpendicular to the direction of relative work or tool motion. The failure mechanisms involved in the cutting of bone, their direct relationships to cutting tool geometry and cutting direction for orthogonal cutting are not accurately defined or quantified. A study of the orthogonal cutting behaviour of bone initiated in the …

Phase Transformations Of Calcium Phosphates Formed In Wet Field Environments, O. M. Clarkin, Mark R. Towler, G. M. Insley, M. E. Murphy

Chemical and Biochemical Engineering Faculty Research & Creative Works

The crystal phase and morphology of calcium phosphate salts precipitated in a wet field environment at temperatures between 30 and 70 °C and pHs between 3 and 8 were examined. Dicalcium Phosphate Dihydrate (DCPD) was the most prevalent phase precipitated. Using accelerated ageing study techniques, precipitates studied were aged, under dry conditions at 50 °C for 8 and 16 days, before being re-examined using XRD, FTIR and SEM techniques. DCPD was found to be most stable when precipitated at 40 °C and 5 pH. Considerably more phase transformation to Octacalcium Phosphate (OCP), Amorphous Calcium Phosphate (ACP) and Hydroxyapatite (HA) was …

Influence Of Two Changes In The Composition Of An Acrylic Bone Cement On Its Handling, Thermal, Physical, And Mechanical Properties, G. Lewis, J. Xu, S. Madigan, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

This study is a contribution to the growing body of work on the influence of changes in the composition of an acrylic bone cement on various properties of the curing and cured material. The focus is on one commercially-available acrylic bone cement brand, Surgical Simplex®P, and three variants of it and a series of properties, namely, setting time, maximum exotherm temperature, activation energy and frequency factor for the polymerization reaction, diffusion coefficient for the uptake of phosphate buffered saline, at 37°C, ultimate compressive strength (UCS), plane-strain fracture toughness, fatigue life (under fully-reversed tension-compression stress), hardness (H) and elastic modulus (both …

Influence Of Acid Washing On The Surface Morphology Of Ionomer Glasses And Handling Properties Of Glass Ionomer Cements, C. M. Crowley, J. Doyle, Mark R. Towler, N. Rushe, S. Hampshire

Chemical and Biochemical Engineering Faculty Research & Creative Works

Acid washing is known to influence the handling properties of ionomer glasses used in glass ionomer cements due to the production of an ion depleted zone on the surface of the glass particles. The influence of acid washing on the particle size distribution and surface area of four glasses was examined by scanning electron microscopy (SEM), particle size analysis (PSA) and accelerated surface area porosimetry (ASAP) and the working and setting times of cements, produced from the glasses, correlated to changes in surface morphology. A linear relationship was found between the specific surface area of acid-washed SiO₂-Al_{2 …}

Preliminary Work On The Development Of A Novel Detection Method For Osteoporosis, P. Moran, Mark R. Towler, S. Chowdhury, J. Saunders, M. J. German, N. S. Lawson, H. M. Pollock, I. Pillay, D. Lyons

Chemical and Biochemical Engineering Faculty Research & Creative Works

Osteoporosis affects both the organic and mineral phases of bone resulting in a decrease in resistance to fracture. Dual x-ray absorptiometry (DEXA) scans are used for diagnosing osteoporosis, which is conventionally characterized by a decrease in mineral density. Unfortunately, some patients who suffer osteoporotic fractures have normal bone density, because both the organic and the mineral phase are affected. However, there are currently no methods of evaluating the health of the organic phase. Patients undergoing treatment for osteoporosis have reported hardening of their fingernails. As the properties of nail and bone may be linked in a comparable, measurable way, this …

Raman Spectroscopy Of The Human Nail: A Potential Tool For Evaluating Bone Health?, Mark R. Towler, A. Wren, N. Rushe, J. Saunders, N. M. Cummins, P. M. Jakeman

Chemical and Biochemical Engineering Faculty Research & Creative Works

Dual X-ray absorptiometry (DEXA) is the current gold standard for the diagnosis of osteoporosis. However, patients can suffer osteoporotic fractures despite normal bone mineral density, partly because of unmeasured influences of both the protein and mineral phases of bone that are affected in osteoporosis. There is currently no clinically applicable method of evaluating the health of the protein phase. The proteins in human nail (keratin) and bone (collagen) require sulphation and disulphide bond (S-S) formation for structural integrity and disorders of either sulphur metabolism or cystathione beta-synthase can lead to structural abnormalities in these tissues. Raman protein spectra provide a …

Orthogonal Linear Regression In Roentgen Stereophotogrammetry, Patrick Atkinson, Jesse V. Benny, Brian J. Mccartin

Mechanical Engineering Publications

Rooted in aerial reconnaissance, mathematical photogrammetry has evolved into a mainstay of biomedical image processing. The present paper develops an algorithm for Roentgen stereophotogrammetry, a method of imaging musculoskeletal systems both static and dynamic, which incorporates a number of novel features employing techniques from projective geometry, orthogonal regression and least squares approximation. Theoretical and numerical evidence is presented of the efficacy of the proposed procedure.

Concept Frequency Distribution In Biomedical Text Summarization, Lawrence H. Reeve, Hyoil Han, Saya V. Nagori, Jonathan C. Yang, Tamara A. Schwimmer, Ari D. Brooks

Computer Sciences and Electrical Engineering Faculty Research

Text summarization is a data reduction process. The use of text summarization enables users to reduce the amount of text that must be read while still assimilating the core information. The data reduction offered by text summarization is particularly useful in the biomedical domain, where physicians must continuously find clinical trial study information to incorporate into their patient treatment efforts. Such efforts are often hampered by the high-volume of publications. Our contribution is two-fold: 1) to propose the frequency of domain concepts as a method to identify important sentences within a full-text; and 2) propose a novel frequency distribution model …

Influence Of Two Changes In The Composition Of An Acrylic Bone Cement On Some Of Its Properties: The Case Of Surgical Simplex® P, S. Madigan, Mark R. Towler, G. Lewis

Chemical and Biochemical Engineering Faculty Research & Creative Works

Influence of two changes in the composition of a self-curing acrylic bone cement on some of its properties are discussed. Acrylic bone cements are widely used in orthopedic surgery for the fixation of joint prosthesis and in vertebroplasty and kyphoplasty for the stabilization and augmentation of fractured vertebrae. The cement's curing process is the result of a free-radical polymerization of a mixture of poly (methyl 1 methacrylate) [PMMA] containing powder and a liquid monomer that has methyl methacrylate (MMA) in it. It is initiated by the decomposition of benzoyl peroxide (BPO) in the powder, activated by a tertiary amine in …

The Influence Of Ultrasonic Setting On Fluoride Release From Glass Polyalkenoate Cements, N. Rushe, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The effects of ultrasonic setting on fluoride release from glass polyalkenoate cements (GPC) were investigated. Cements based on two different aluminosilicate glasses that contained silica, alumina, phosphate, and strontia were used for the experiment. A series of GPCs were examined to show that increased release F^- ion occurs, regardless of GPC composition. The results show that there is a greater release of fluoride from the ultrasonically set samples than those set chemically, regardless of the chemical composition. The snap set caused by the ultrasound is likely to be due to a combination of cavitation, improved mixing of the constituents, …

Calcium And Zinc Ion Release From Polyalkenoate Cements Formed From Zinc Oxide/Apatite Mixtures, Mark R. Towler, S. Kenny, D. Boyd, T. Pembroke, M. Buggy, A. Guida, R. G. Hill

Chemical and Biochemical Engineering Faculty Research & Creative Works

Calcium and zinc ion release from hydroxyapatite-zinc oxide-poly (acrylic acid) (HAZnO-PAA) composite cements into deionised water was investigated as a function of HA content, PAA concentration, PAA molecular weight and maturation time. At any given maturation time, zinc ion release was constant until the HA content was at the maximum loading (60 wt%) resulting in the cement matrix breaking up, allowing exacerbated ion release. The calcium ion release increased with increased HA content in the composite until the maximum loading where the release drops off. Up to this point, the release of both ionic species was proportional to square root …