Investigative Techniques Commons^™

Cyberknife Radiation Modeling: Effects Of Relaxed Translational And Rotational Constraints On Healthy Tissue Irradiation, Sudha Bhavaroop Potineni

Electrical & Computer Engineering Theses & Dissertations

The Cyberknife system is a robotic radio surgery instrument that is used to treat cancers in different parts of the human body. Because of its accuracy and precision, it has become one of the best radio surgery systems in the world. However, even with Cyberknife the treatment time for one session takes from 30 minutes up to 120 minutes depending on the size, shape, and position of the tumor in the human body. In this research, a solution is presented to aid in reducing this long treatment time. An algorithm is developed which simulates the amount of the healthy tissue …

The Use Of Motion Analysis Technology As An Alternative Means Of Assessing Spinal Deformity In Patients With Adolescent Idiopathic Scoliosis, Matthew J. Solomito

Master's Theses

Adolescent Idiopathic Scoliosis (AIS) is a three dimensional deformity of the spine that causes abnormal curvatures in the coronal and sagittal planes and abnormal vertebral rotations. The gold standard for diagnosing and tracking the progression of the deformity is through the use of repeated radiography and a patient can receive upwards of fifteen radiographic series over the course of treatment, which exposes this population to an increased risk of radiation-dependent complications.

This thesis presents the necessary calculations and the marker set required to make the motion capture technology a viable alternative to radiographs, in an effort to reduce the patient’s …

Use Of A Spine Robot Employing A Real Time Force Control Algorithm To Develop, Simulate, And Compare Spinal Biomechanical Testing Protocols: Eccentric Loading, Pure Moment, And A Novel Head Weight Protocol, Daniel Mark Wido

Theses and Dissertations (ETD)

In vitro testing provides a critical tool for understanding the biomechanics of the subaxial cervical spine. Previous common testing protocols used to evaluate the subaxial cervical spine include Pure Moment (PM), follower load, and eccentric lever arm (EL) loading methods. Although these methods are widely accepted, there is always a goal to try to better simulate physiologic loading conditions. While the follower load attempts to simulate compression due to muscle activation, no previous protocol has taken into account the constant vertical force vector applied to C2 produced by the weight of the human head. Furthermore, we are unaware of previous …

Ultrasound Imaging Of Lumbar Multifidus Immediately Following Three Physical Therapy Techniques In Asymptomatic Individuals, Victoria Byers, Steven Lim, Kathryn Rice

UNLV Theses, Dissertations, Professional Papers, and Capstones

Study Design

Randomized, blinded, cohort, within subjects design.

Background and Objective

The effects of different manual therapy (MT) techniques on lumbar multifidus (LM) thickness have been investigated in subjects with low back pain (LBP) but have not been investigated in asymptomatic subjects. The objective of this study was to examine the immediate effects of mobilization and manipulation on contraction thickness of LM in healthy individuals.

Methods and Measures

Forty-two healthy individuals participated in the study. Ultrasound imaging techniques were used to record LM thickness (L4-5 level) at rest, during an abdominal drawing in maneuver (ADIM), and during a prone upper …

Use Of A Multi-Axis Robotic Testing Platform To Investigate The Sagittal Mechanics Of The Multi-Body Lumbar Spine, Jessica Rose Stubbs

Theses and Dissertations (ETD)

A biomechanical study was performed to compare range of motion of the multi-body lumbar spine using three different protocols: pure moment, eccentric loading, and a new method called combined loading moment. The objectives of the study were to introduce a new protocol that overcomes the limitations of previous methods by applying more realistic loading conditions and to compare the range of motion of this new protocol to those of eccentric loading and pure moment protocols within the same specimen pool. The second objective of this study was to compare the data sets of these three protocols to both in vivo …

Prediction Of Brain Tumor Progression Using Multiple Histogram Matched Mri Scans, Debrup Banerjee, Loc Tran, Jiang Li, Yuzhong Shen, Frederic Mckenzie, Jihong Wang, Ronald M. Summers (Ed.), Bram Van Ginneken (Ed.)

Electrical & Computer Engineering Faculty Publications

In a recent study [1], we investigated the feasibility of predicting brain tumor progression based on multiple MRI series and we tested our methods on seven patients' MRI images scanned at three consecutive visits A, B and C. Experimental results showed that it is feasible to predict tumor progression from visit A to visit C using a model trained by the information from visit A to visit B. However, the trained model failed when we tried to predict tumor progression from visit B to visit C, though it is clinically more important. Upon a closer look at the MRI scans …

Development Of Fetal Movement Between 26 And 36 Weeks’ Gestation In Response To Vibroacoustic Stimulation, Marybeth Grant-Beuttler, Laura M. Glynn, Amy L. Salisbury, Elyssia Poggi Davis, Carol Holliday, Curt A. Sandman

Psychology Faculty Articles and Research

BACKGROUND: Ultrasound observation of fetal movement has documented general trends in motor development and fetal age when motor response to stimulation is observed. Evaluation of fetal movement quality, in addition to specific motor activity, may improve documentation of motor development and highlight specific motor responses to stimulation.

AIM: The aim of this investigation was to assess fetal movement at 26 and 36-weeks gestation during three conditions (baseline, immediate response to vibro-acoustic stimulation (VAS), and post-response).

DESIGN: A prospective, longitudinal design was utilized.

SUBJECTS: Twelve normally developing fetuses, eight females and four males, were examined with continuous ultrasound imaging.

OUTCOME MEASURES: …

Yeast As A Model For Studying Aβ Aggregation, Toxicity And Clearance, Prashant R. Bharadwaj

Theses: Doctorates and Masters

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder of the central nervous system, characterised by acute memory loss and behavioural symptoms. The AD brain is characterized by the presence of senile amyloid plaques associated with degenerating neurites and inflammatory processes. The major protein component of these amyloid deposits is the amyloid beta (Aβ) protein. The Aβ protein is a 40 or 42 amino acid cleavage product of APP (Amyloid Precursor Protein) which is produced in low levels in the normal ageing brain. Although senile amyloid plaques is the major pathological hallmark of AD brains, accumulating evidence has been presented to …

The Effect Of Sternocleidomastoid Muscle Activation Pattern And Feedback Condition On The Vestibular Evoked Myogenic Potential., Mary Jo Davenport

Electronic Theses and Dissertations

The vestibular evoked myogenic potential (VEMP) has been shown to be clinically useful in providing diagnostic information regarding the function of the otolith receptors, inferior vestibular nerve, and vestibulospinal pathways. The VEMP is a biphasic response elicited by loud clicks or tone bursts and recorded from the tonically contracted sternocleidomastoid (SCM) muscle. Because the VEMP is an inhibitory response, it is important to investigate stimulus and parameter characteristics in order to determine the optimal test protocol and maximize clinical usefulness. The aims of this study were 1) to evaluate the effects of 4 different methods of SCM muscle activation and …

The Development And Psychometric Testing Of A Hypertension Knowledge Instrument In A Vulnerable Population, Crescent Elayne Rowell

Theses and Dissertations (ETD)

The primary objective of the study was to assess the psychometric properties of a hypertension knowledge instrument in a vulnerable population. The secondary objective was to determine the association between hypertension knowledge and outcomes such as systolic and diastolic blood pressure and hemoglobin A1c.

A cross-sectional study was conducted using a convenience sample of 196 adults aged 18 years and older with hypertension. Item analysis was conducted to determine the reliability of the instrument. The factor structure was determined and confirmed using exploratory factor analysis and confirmatory factor analysis, respectively. Logistic regression analysis was used to determine the association between …

Conceptual And Methodological Issues Relevant To Cytokine And Inflammatory Marker Measurements In Clinical Research., Xin Zhoua, Maren S. Fragala, Janet E. Mcelhaney, George A. Kuchel

UCHC Articles - Research

PURPOSE OF REVIEW: To provide clinical investigators with an understanding of factors to consider when wishing to add cytokine and inflammatory marker measurements to their studies. RECENT FINDINGS: Inflammation involves complex and coordinated responses of the immune system to tissue damage. In the absence of tools to routinely assess inflammation within living tissues, measurements of humoral factors such as cytokines and other inflammatory mediators or markers can provide predictive clinical information and insights into disease mechanisms. Historically, enzyme-linked immunosorbent assays (ELISAs) became the gold standard, yet this approach of measuring a single protein in each sample limits the amount of …

A Passive Pure Moment Protocol For Testing Spine Segments: Development And Application, Kyle David Fraysur

Theses and Dissertations (ETD)

The pure moment protocol is the accepted standard for performing in-vitro biomechanical testing of spinal devices. Published studies predominantly report range of motion and flexibility data, but information regarding the segment center of rotation is also relevant. Most current pure moment platforms are not sensitive enough to accurately calculate the instantaneous axis of rotation (IAR) for a segment throughout a bending motion. The purpose of this study was to simulate a pure moment protocol using a programmable spine robot, and use the data gathered to calculate the IAR for harvested specimen and those implanted with a constrained total disc replacement …

Small Intestine Submucosa For Repair Of Injured Rabbit Cornea: A Pilot Study, Mark Nicholas Perenich

PCOM Biomedical Studies Student Scholarship

Corneal injuries blind approximately 15 million people worldwide annually. Current methods of treatment have several disadvantages with respect to cost and availability. This study evaluated a small intestine submucosa (SIS) xenograft treatment for a severe corneal injury. SIS could be a favorable alternative to the current treatment methods, because it is inexpensive to produce and abundant where pigs are consumed. A severe ocular injury was created in the right eye of 5 rabbits by n-heptanol and mechanical debridement of the cornea and limbus. The cornea was then evaluated with fluorescence stain and a SIS xenograft was used for treatment. Clinical …

Quantification Of Circulating Melanoma Cells, Jamie Freeman

Theses : Honours

Current prognostic techniques for Cutaneous Malignant Melanoma (CMM), a highly aggressive and drug resistant skin cancer, are inadequate at managing the disease and identifying early stage patients requiring treatment. It is thought that Circulating Tumour Cells (CTCs), which circulate in patient blood after being shed from solid tumours, may be useful in enhancing prognostic techniques and it has previously been shown in other malignancies that the presence of CTCs in patient blood is associated with poor prognosis. In CMM, CTCs can be detected through RT-PCR for melanoma associated markers, although this technique does not allow CTCs to be quantified. In …

Using Cone Beam Computed Tomography To Identify A Prediction Model For Obstructive Sleep Apnea, Jodi Parker

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Obstructive Sleep Apnea (OSA) patients have increased risk of morbidity and mortality. Early diagnosis may reduce morbidity and mortality. Prediction of OSA from imaging may help to identify OSA patients earlier in life. CBCT can be used for OSA diagnostic imaging due to its three-dimensional (3D) visualization of the upper airway and craniofacial complex. Magnification associated with conventional 2D radiography is eliminated with CBCT, and radiation to the patient is significantly less than previous modalities used to measure craniofacial & airway measurements associated with OSA. During a CBCT scan, the patient's image is taken supine, rather than the upright …

Investigation Of Magnetic Resonance Imaging And Spectroscopy For The Detection Of Breast Cancer, Robert Thomas Etnire

UNLV Theses, Dissertations, Professional Papers, and Capstones

Magnetic resonance imaging (MRI) of the breast offers an alternative to screening mammography which may benefit those women at high risk for breast cancer, women under the age of 40, and those with dense breast tissue. One concern with MRI is the number of high false positives. Coupling MRI with magnetic resonance spectroscopy(MRS) may lower the number of false positives, and thus improve the diagnostic capabilities of MRI for the clinician. MRS for breast imaging focuses on the total choline containing compounds in the spectra in the suspected breast lesion to analyze areas of concern. The results of the study …

Using Thermoluminescent Dosimeters To Measure The Dose From High And Low Energy X-Ray Sources, Wesley Leon Boyd

UNLV Theses, Dissertations, Professional Papers, and Capstones

This work focused on using thermoluminescent dosimeters (TLDs) to measure the doses from two x-ray sources, a CT scanner and a linear accelerator (linac). In addition ion chambers were used to determine the isodose contours from the operation of the linac. 1mm x 1mm x 1mm TLD-100 microcubes were placed in a Lawrence Livermore National Laboratory (LLNL) torso phantom and irradiated using a Toshiba Aquilion One 320-Slice CT Scanner. Different thicknesses of shielding composed of antimony and bismuth powder suspended in an ethylene copolymer were used to shield the phantom and the dose reduction was measured. The dose reduction ranged …

The Use Of Spectroscopic Techniques In The Characterization Of Mycobacterial Metabolites, Engy Abdelhameed Mahrous

Theses and Dissertations (ETD)

The mycobacterial cell wall metabolites have always imposed great challenges to researchers due to their unusual complexity and structural diversity. A lot of research efforts have been directed towards the evaluation of these metabolites and the role they play in the pathogenesis and virulence of different serious human pathogens including Mycobacterium tuberculosis the causative agent of tuberculosis (TB). In the genomic era, it is crucial to develop new methodologies to analyze these components from a global perspective in a comprehensive and well-validated manner.

Towards this end, we developed a rapid NMR-based approach to produce metabolic profiles in the form of …

Cultural Determinants Affect Implementation Of Good Clinical Practice (Gcp) In Human Research Studies In Malawi, Africa, Joann Jeanne Schmidt

Master's Theses and Doctoral Dissertations

Clinical research conduct and Good Clinical Practice (GCP) implementation are influenced by local culture. This study examines the experiences of 26 clinical research personnel in Malawi, Africa, in order to define relevant issues, identify solutions, and give voice to local investigators. Qualitative, semi-structured interviews were conducted, audio-recorded, transcribed, and analyzed. Six themes, related to cultural determinants, emerged: 1) communitybased decision-making, 2) illiteracy, 3) patient identifiers, 4) local myths and misconceptions, 5) poverty and disease, and 6) barriers to teamwork. Findings revealed that: 1) Malawians are best at identifying local solutions, 2) operations research is needed 3) greater networking and communication …

Demographic Profile Of Clinical Research Volunteers: Improving The Effectiveness Of Promotional Recruitment, Amanda M. Mcallister

Master's Theses and Doctoral Dissertations

Background: Successfully recruiting participants for clinical trials is a challenge that crosses all medical disciplines. Slow enrollment to clinical trials delays the completion of clinical research studies.

Objectives: This study collected demographic data of current and past clinical trial volunteers. Furthermore, it examined similarities and differences between clinical trial volunteers, which provides deeper understandings of who volunteers are and which may allow for improved education and recruitment of subjects.

Methods: 87 adults who had participated in at least one clinical research study were surveyed.

Findings:

*Healthcare represented the most common career at 27.6%.

*93.1% received education beyond high school.

*0% …

Automatic Diagnosis For Prostate Cancer Using Run-Length Matrix Method, Xiaoyan Sun, Shao-Hui Chuang, Jiang Li, Frederic Mckenzie, Nico Karssemeijer (Ed.), Maryellen L. Giger (Ed.)

Electrical & Computer Engineering Faculty Publications

Prostate cancer is the most common type of cancer and the second leading cause of cancer death among men in US¹. Quantitative assessment of prostate histology provides potential automatic classification of prostate lesions and prediction of response to therapy. Traditionally, prostate cancer diagnosis is made by the analysis of prostate-specific antigen (PSA) levels and histopathological images of biopsy samples under microscopes. In this application, we utilize a texture analysis method based on the run-length matrix for identifying tissue abnormalities in prostate histology. A tissue sample was collected from a radical prostatectomy, H&E fixed, and assessed by a pathologist …

Use Of Compliant Interbody Force Sensing Grafts To Compare Load Sharing Properties Of Unidirectional And Bidirectional Multilevel Dynamic Translational Anterior Cervical Plates, Jason Roscoe Roberson

Theses and Dissertations (ETD)

INTRODUCTION: Pseudoarthrosis is a relatively rare complication following anterior cervical arthrodesis, and is felt to be related to stress shielding. To address this, dynamic anterior cervical plates have emerged to maintain load sharing as an arthodesis matures. Dynamic plates can translate bidirectionally (allow translation in compressive and tensile loads), or unidirectionally (allow translation in compression, but maintain its position under tensile loads). The objective of this study was to compare the graft load mechanics between three plated conditions during settling using compliant interbody load cells: A static (fixed, non-moving) plate, a unidirectional multi-level translational plate design, and a bidirectional two-level …

A Kinematics-Based Testing Protocol To Study The Mechanics Of The Human Lumbar Spine, Nephi A. Zufelt

Theses and Dissertations (ETD)

The objective of this work was to develop a new kinematics-based testing protocol to quantify the axial and shear force components and rotational moment properties of the human cadaveric lumbar motion segment unit (MSU) in response to specific kinematic inputs. Modern, non-fusion spinal devices claim to treat degenerative disc disease better than traditional fusion surgery. Though there have been many biomechanical studies completed on these devices, there is still a debate over their efficacy. Conventional testing methods provide insight into the rotational properties of the MSU but lack the sensitivity or capacity to quantify lumbar MSU’s mechanical properties including shear …

Acquisition De Modèles Pour L’Étude De L’Absorption Percutanée Des Substances Chimiques : Cellules De Diffusion À Flux Continu, Claude Viau, Suzanne Leroux, Ross Thuot, Sophie Lim

Rapports de recherche scientifique

Dans les milieux de travail où des substances chimiques sont utilisées, celles-ci peuvent se retrouver dans l’air. Les employés peuvent donc y être exposés par le fait de la respiration. C’est d’ailleurs pour ça que le règlement sur la santé et la sécurité du travail donne des valeurs limites d’exposition dans l’air pour près de 700 substances chimiques. Mais il est aussi possible d’être exposé par le contact des substances avec la peau. Quand on veut savoir à quel point un travailleur peut absorber des substances dans son organisme de cette manière, on doit savoir trois choses principales :

• la …

Cost Saving By Reloading The Multiband Ligator In Endoscopic Esophageal Variceal Ligation: A Proposal For Developing Countries, Zaigham Abbas, Lubna Rizvi, Umair Syed Ahmed, Khalid Mumtaz, Wasim Jafri

Department of Medicine

Aim: To assess the cost savings of reloading the multiband ligator in endoscopic esophageal variceal ligation (EVL) used on the same patient for subsequent sessions.

Methods: This single centre retrospective descriptive study analysed patients undergoing variceal ligation at a tertiary care centre between 1st January, 2003 and 30th June, 2006. The multiband ligator was reloaded with six hemorrhoidal bands using hemorrhoidal ligator for the second and subsequent sessions. Analysis of cost saving was done for the number of follow-up sessions for the variceal eradication.

Results: A total of 261 patients underwent at least one session of endoscopic esophageal variceal ligation …

Prostate Segmentation On Pelvic Ct Images Using A Genetic Algorithm, Payel Ghosh, Melanie Mitchell

Computer Science Faculty Publications and Presentations

A genetic algorithm (GA) for automating the segmentation of the prostate on pelvic computed tomography (CT) images is presented here. The images consist of slices from three-dimensional CT scans. Segmentation is typically performed manually on these images for treatment planning by an expert physician, who uses the “learned” knowledge of organ shapes, textures and locations to draw a contour around the prostate. Using a GA brings the flexibility to incorporate new “learned” information into the segmentation process without modifying the fitness function that is used to train the GA. Currently the GA uses prior knowledge in the form of texture …

The Mind-Body Connection: The Association Between Adolescent Locus Of Control And Indicators Of Physical Health, C. Jayne Brahler, James Cropper

Physical Therapy Faculty Publications

Locus of control (LOC) describes an individual’s generalized beliefs or expectancies that their reinforcements are under internal versus external control (1). An individual exhibits either an internal or external LOC. This study examines the link between LOC and selected health risk factors in adolescents. A convenience sample of 167 high school physical education students completed a 13-item LOC questionnaire based on Rotter’s 1966 instrument.

Various anthropometric measurements, blood pressure, body mass index (BMI), and body fat were recorded on all subjects. A subsample of 61 female students received blood chemistry analysis that included a lipid profile, hemoglobin A1c (HbA1c), Apo …

Three Dimensional Echocardiography In Congenital Heart Defects., Girish S. Shirali

Manuscripts, Articles, Book Chapters and Other Papers

Three dimensional echocardiography (3DE) is a new, rapidly evolving modality for cardiac imaging. Important technological advances have heralded an era where practical 3DE scanning is becoming a mainstream modality. We review the modes of 3DE that can be used. The literature has been reviewed for articles that examine the applicability of 3DE to congenital heart defects to visualize anatomy in a spectrum of defects ranging from atrioventricular septal defects to mitral valve abnormalities and Ebstein's anomaly. The use of 3DE color flow to obtain echocardiographic angiograms is illustrated. The state of the science in quantitating right and left ventricular volumetrics …

The Development Of The Self-Injury Self-Report Measure., Sonia Lorraine Coney

Electronic Theses and Dissertations

Despite the amount of research that has been conducted on self-injury there is a lack of empirically validated instruments with which to measure self-injurious behavior. The present study developed a measure to examine self-injury and the associated features. Undergraduate students (n = 184) were administered a set of surveys to assess demographics, self-injurious behavior, suicidal ideation, Axis I and Axis II disorders, and impulsivity. Results indicated that a reliable measure, able to assess the extent of self-injury as well as associated features, was developed. Such a measure will enable clinicians to better assess self-injury and enable researchers to more fully …

Biochemical Characteristics Of Inconsistent Free T₄ Assays, Kristofer S. Fritz

Loma Linda University Electronic Theses, Dissertations & Projects

Serum levels of free thyroxine (T₄) are helpful in the clinical evaluation of patients who are suspected of having thyroid disease, since free T₄ (unbound) is known to closely relate to hyper, eu and hypothyroidism. There are documented inconsistencies among commercially available direct free thyroxine immunoassays. The biochemical basis for these inconsistencies is not understood and has not been characterized. Direct free T₄ measurements have been linked to both T₄-binding serum protein concentrations and protein-bound T₄ concentrations. A free T₄ reference method using direct equilibrium dialysis radioimmunoassay has been well characterized. New …