Biomedical Engineering and Bioengineering Commons^™

Enhanced Na+/H+ Exchange During Ischemia And Reperfusion Impairs Mitochondrial Bioenergetics And Myocardial Function, Mohammed Aldakkak, David F. Stowe, James S. Heisner, Marisha Spence, Amadou K.S. Camara

Biomedical Engineering Faculty Research and Publications

Inhibition of Na+/H+ exchange (NHE) during ischemia reduces cardiac injury due to reduced reverse mode Na+/Ca2+ exchange. We hypothesized that activating NHE-1 at buffer pH 8 during ischemia increases mitochondrial oxidation, Ca2+ overload, and reactive O2 species (ROS) levels and worsens functional recovery in isolated hearts and that NHE inhibition reverses these effects. Guinea pig hearts were perfused with buffer at pH 7.4 (control) or pH 8 +/- NHE inhibitor eniporide for 10 minutes before and for 10 minutes after 35- minute ischemia and then for 110 minutes with pH 7.4 buffer alone. Mitochondrial NADH and FAD, [Ca2+], and superoxide …

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 …

Cephalometric Analysis Using Magnetic Resonance Imaging, Wade A. Williams

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The purpose of this study was to determine if T1-weighted 3D magnetic resonance images performed at 3.0 Tesla could be used to conduct routine orthodontic cephalometric analysis.

Methods: Three cranial imaging methods were compared using sixteen non-growing subjects (10 male and 6 female) who were not claustrophobic, did not have any metallic restorations on the distal of first molars, had no medical implants and the female subjects were not pregnant. Sagittal cranial images were produced by three methods: (1) a digital lateral cephalometric (LC) radiograph (Orthophos XG Plus, Sirona^TM, Bensheim, Germany), (2) a 12-inch FOV cone beam …

Design And Fabrication Of A Microneedle For The Implantation Of Floating Microstimulators, Faysal Ahmed

Theses

Neural prosthetics are used to stimulate any remaining functional nervous tissue in order to restore function in visual, auditory, or other physiological components associated with the nervous system. Microelectrodes have been used in stimulating and detecting electrical activity in neurons. When stimulating or recording neural tissue activity using microelectrodes, there are usually many problems and difficulties in obtaining the correct functionality and results. There is great difficulty in placing these microelectrodes in a specific location in the central nervous system due to various problems with the methodology used. Many different techniques such as the traditional interconnected microelectrodes have been an …

Classification Of Hand Held Shapes And Locations In Continuous Signing, Swetha Karri

Theses

Sign language for the deaf and hearing impaired replaces speech with manually produced signs. Each sign has been categorized as being combinations of handshape, movement, orientation, location, and facial expressions. Of the five sign parameters, this thesis focuses on classification of two of the main parameters, the hand shapes and locations, in continuous signing.

Since the nature of hand shapes is transient and not static, neural networks was used as a classifier for hand shapes. And since locations in sign language are defined by linguistic variables rather than by hard core position values, fuzzy logic was used as a classifier …

Photoplethysmorgraph-Derived Respiration, Priyanka Pankaj Shah

Theses

Stress & Motivated Behavioral Institute (SMBI) has developed a research program to provide an objective evaluation of the physiological and neurocognitive impact of human electromuscular muscular interference (HEMI) devices in humans. The initial step is to understand their physiological impact, which is characterized by vital signs. Volunteers are recruited from HEMI training programs with the provision that data collection can not interfere with training. Thus, an ambulatory system was assembled. There are two main issues in the current ambulatory system, one of which is the reliability of the respiration signal obtained using a strain gauge respiration band, mainly due to …

Biomechanical Testing Of Upright Range Of Motion Versus Overhead Supine Range Of Motion, Linda Uko

Theses

Rehabilitation of an elbow, following injury, is not a well-studied subject. Clinically, there is not a general consensus on which recovery method is optimal for healing an unstable elbow. When dealing with medial collateral ligament deficiency, many authors have proposed several forearm positions that will yield proper healing of the unstable elbow. Some researchers believe that active mobilization of the elbow with the arm in a vertical position is a safe protocol for rehabilitation with the forearm oriented in a supine pronated position. It was also mentioned that the compressive forces due to the active mobilization of the arm will …

A Novel Method For Characterization Of Peripheral Nerve Fiber Size Distributions By Group Delay Measurements And Simulated Annealing Optimization, Robert B. Szlavik, Galen E. Turner, Iii

Biomedical Engineering

The ability to determine the characteristics of peripheral nerve fiber size distributions would provide additional information to clinicians for the diagnosis of specific pathologies of the peripheral nervous system. Investigation of these conditions, using electro-diagnostic techniques, is advantageous in the sense that such techniques tend to be minimally invasive yet provide valuable diagnostic information. One of the principal electro-diagnostic tools available to the clinician is the nerve conduction velocity test. While the peripheral nerve conduction velocity test can provide useful information to the clinician regarding the viability of the nerve under study, it is a single parameter test that yields …

Cues For Cellular Assembly Of Vascular Elastin Networks, Chandrasekhar Kothapalli

All Dissertations

Elastin, a structural protein distributed in the extracellular matrix of vascular tissues is critical to the maintenance of vascular mechanics, besides regulation of cell-signaling pathways involved in injury response and morphogenesis. Thus, congenital absence or disease-mediated degradation of vascular elastin and its malformation within native vessels due to innately poor elastin synthesis by adult vascular cells compromise vascular homeostasis. Current elastin regenerative strategies using tissue engineering principles are limited by the progressive destabilization of tropoelastin mRNA expression in adult vascular cells and the unavailability of scaffolds that can provide cellular cues necessary to up-regulate elastin synthesis and regenerate faithful mimics …

Engineered Micro-Environments And Vibrational Culture Systems For Vocal Fold Tissue Engineering, Jaishankar Kutty

All Dissertations

Voice is produced by the conversion of aerodynamic energy from exhalation to acoustical energy for voice production by the vocal folds (membranous connective tissue) located in the larynx. The quality of voice depends on the biomechanical properties of the multi-layered vocal fold tissue which derive from its extracellular matrix (ECM) organization and composition. The wound healing response to vocal fold injuries is characterized by scarring and subsequent dysphonia due to alterations in the biomechanical properties of the tissue.
The work presented here is motivated by the importance of voice in maintaining quality of life and the inability of current treatment …

The Spaceflight Environment And The Skeletal System, Eric Bandstra

All Dissertations

The spaceflight environment presents many challenges to the human body. Bone loss in astronauts is a well known consequence of reduced loading in the weightless environment of low-earth orbit. Recent studies have also indicated that spaceflight relevant types of radiation (at relatively high doses) have deleterious effects on trabecular bone. Both of these represent potential skeletal challenges during long-duration spaceflight. The objective of these studies is to examine the response of bone to models of the spaceflight environment.
Astronauts will likely absorb doses of protons and heavy ions during lengthy missions outside the Earth's magnetosphere. Following exposure to a range …

Chitosan Derivatives For Tissue Engineering, Yongzhi Qiu

All Dissertations

Chitosan, a naturally occurring polysaccharide, and its derivatives have been widely explored for biomedical applications due to their biocompatibility and biodegradability. In our studies, we developed a series of chitosan derivatives through chemical modifications. These chitosan derivatives not only possess better processibility in scaffolds fabrication, but also show excellent potentials in tissue engineering applications, including blood vessel and bone tissue engineering.
The excellent antithrombogenic property is crucial for vascular engineering applications, especially in engineering small-diameter blood vessels. In our studies, chitosan was chemically modified by phthalization and the phthalized chitosan exhibited great antithrombogenic property. Through a wet- phase-inversion process, tubular …

Image-Guided Raman Spectroscopic Recovery Of Canine Cortical Bone Contrast In Situ, Subhadra Srinivasan, Matthew Schulmerich, Jacqueline H. Cole, Kathryn Dooley, Jaclynn M. Kreider, Brian W. Pogue

Dartmouth Scholarship

Raman scattering provides valuable biochemical and molecular markers for studying bone tissue composition with use in predicting fracture risk in osteoporosis. Raman tomography can image through a few centimeters of tissue but is limited by low spatial resolution. X-ray computed tomography (CT) imaging can provide high-resolution image-guidance of the Raman spectroscopic characterization, which enhances the quantitative recovery of the Raman signals, and this technique provides additional information to standard imaging methods. This hypothesis was tested in data measured from Teflon tissue phantoms and from a canine limb. Image-guided Raman spectroscopy (IG-RS) of the canine limb using CT images of the …

Department Of Biological Systems Engineering Newsletter, Volume 4, Number 1, August 2008

BSE Department Magazine

Contents:
New Biomedical Lab Makes Debut
From the Department Head
The Dean's List
Meet the Faculty
Alumni News
Student News
UCARE
Graduates
John Miller: A Success Story
Discover Your Career: Mechanized Systems Management
Alumnus Profile
Faculty and Staff News
Comings and Goings
Spreading the word about No-till

Targeted Drug Delivery To Human Aortic Smooth Muscle Cells Using Biodegradable Nanoparticles, Danyel Specht

Bioengineering Theses - Archive

Restenosis is a common problem that can occur in angioplasty patients. In order to reduce the restentosis rate, various treatments such as glucocorticoids and drug eluting stents have been used for angioplasty patients. However, their limitations include the inefficient delivery of drugs to inhibit smooth muscle cell proliferation, a major cause of restenosis. Therefore, we propose the use of biodegradable nanoparticles as a drug delivery system for transporting a therapeutic agent to human aortic smooth muscle cells (HASMC) to prevent their proliferation. In this study the glucocorticoid dexamethasone (DEX) was chosen as the therapeutic agent. A biodegradable polymer, poly (D,Llactide-co-glycolide) …

Subcellular Light Activation, Control And Manipulation Using A Dynamically Reconfigurable Nanopatterning System, Amruta Rajiv Joshi

Bioengineering Theses - Archive

Cellular communication is the basis of all cellular activities and functions. Cell signaling is crucial in the processes of tissue maintenance, tissue development and homeostasis. Errors in transmission or interpretation of these signals can result in the onset of diseases like cancer. Efforts have been made to probe into the communication between cells, and the extracellular signals that cells transmit to each other. There is however, a necessity to understand cell communication within the cellular components themselves and to be able to perform a nanoscale analysis of the cell organelle behavior. Many cellular mechanisms involve processes at the subcellular level, …

Microfluidic Flow Cytometer For High Throughput Label Free Cell Analysis, Sajal Chirvi

Bioengineering Theses - Archive

Microfluidic flow cytometer for high throughput label free cell analysis is proposed. Detection of cell morphology plays an important role in determination of state of health and diagnosis of many diseases such as sickle cell anemia, cancer, urine analysis, blood analysis etc. The platform proposed integrates label free cell analysis, microfluidic platform and high throughput imaging. Label free analysis helps in analyzing cells without altering cell/protein of interest and also allows biophysical characterization of living cells. Microfluidic platform used is fabricated from soft lithography. It mimics biological environment due to its channel confinement and is biocompatible. Being optically clear (PDMS), …

Cytotoxicity Evaluation Of Temperature Sensitive Poly(N-Isopropylacrylamide) Nanoparticles For Drug Delivery, Aniket Sharadrao Wadajkar

Bioengineering Theses - Archive

The objective of this research project was to develop temperature sensitive poly(N-isopropylacrylamide) (PNIPA) nanoparticles for drug delivery applications. These nanoparticles were formulated by a radical polymerization method, and their toxicity was studied in vitro using MTS assays and various cell types such as fibroblasts, smooth muscle cells, and endothelial cells. Cytotoxicity results did not show a significant difference in cell survival when cells were exposed to different particle sizes (100, 300, and 500 nm). In addition, dose studies of 100 nm nanoparticles showed that the cells exposed to PNIPA nanoparticles at concentrations less than or equal to 5 mg/ml were …

Exploratory Study Of Gold Nanoshell As A Therapeutic Thermal Ablation Agent For Cancer Treatment Using Laboratory And Animal Tissue Phantoms, Yajuvendra Rathore

Bioengineering Theses - Archive

Prostate cancer is the most common male cancer in the United States and the second leading cause of male death from cancer. Surgical removal of the prostate is associated with high risks of surgical complications and consequences such as incontinence and sexual dysfunction. In my study, I have investigated a nanoparticle-assisted photothermal therapeutic method that may be used for treatment of prostate cancer in the future. This method is minimally-invasive and uses gold nano-shells as hyperthermia agents to treat localized necrosis of cancer cells. I have conducted a feasibility study for a new class of NIR absorbing nanoparticles called Gold …

Study Of Normobaric Hyperoxia Effects During Focal Hypoxia-Ischemic Injury In Mice Using Optical Spectroscopy Measurements, Shereen Mohideen

Bioengineering Theses - Archive

Optical spectroscopy has seen tremendous growth and development in recent years and has been extensively used to characterize the optical properties of biological tissues. The purpose of this study is to investigate the values of oxygen saturation and concentration of hemoglobin in mice with focal hypoxic ischemia after being recovered in normobaric hyperoxia. Mice at five different age levels were used for this purpose, in order to see the effects of hyperoxia at different developmental stages of the brain; ischemia was induced in them by ligating their right carotid artery and subjecting them to hypoxic (8% oxygen) environment for half …

Model Driven Analysis Of Optical Reflectance Spectroscopy For Detection Of Human Prostate And Kidney Cancers, Aditya Vivek Mathker

Bioengineering Theses - Archive

Renal cell carcinoma is one of the most common forms of kidney cancer originating from the renal tubule. During surgery, it is difficult for the surgeons to identify the cancer tissue from the normal tissue and also the benign tumor from malignant tumor. Moreover, prostate cancer is the leading cause of death amongst men in the United States. In this study, optical reflectance spectroscopy with short source-detector separation is used as a minimally invasive technique to differentiate normal tissues from tumor lesions and also to differentiate benign from malignant tissues in renal cell carcinoma. Clinical post-operative readings were obtained using …

Comparison Of Hemodynamic Response Non-Linearity Using Simultaneous Functional Near Infrared Spectrsoscopy And Magnetic Resonance Imaging Modalities, Renuka Parlapalli

Bioengineering Theses - Archive

Blood oxygenation level dependent (BOLD) response, which is measured by functional magnetic resonance imaging (fMRI), is known to be a combination of various vascular parameters, among which deoxy-hemoglobin is argued to be a major contributor. Functional near infrared spectroscopy (fNIRS) though limited in its spatial resolution provides a promising tool to study cortical activations, due to its specificity of independent measurement of blood parameters (Oxy, De-oxy and Total Hemoglobin), high temporal resolution and ease of use. To integrate the best aspects of two imaging modalities, it becomes important to study the close relationship between the two imaging modalities. A finger …

Surgical Fluorescence Imager For Visualizing Anteriorly Placed Biliary Structures, In-Vivo During Human Cholecystectomy, Santosh Hariharan

Bioengineering Theses - Archive

Cholecystectomy is one of the most common procedures occurring in United States to cure gall bladder diseases. There are two means of performing this procedure, Open Cholecystectomy and Laparoscopic Cholecystectomy, the later one being more frequent. The critical issue while performing Cholecystectomy is injury to Common Bile Duct (CBD) which could cause post procedural complications. Since the CBD is under fat layer it is important to image and locate the CBD during the procedure. The novel fluorescence imager developed in this project would help visualize the CBD by using the fluorescence properties of Indocyanine Green, to be injected into the …

Study Of Nirs Based Motor Cortex Activation Patterns In Cerebral Palsy Affected Kids Using Image Based Metrics, Nayan Jaikrishna Asanani

Bioengineering Theses - Archive

In recent years the National Institutes of Health has placed great emphasis on addressing the emergent need to accelerate translation of laboratory discoveries into clinical practice. The proposed study is very much aligned with this NIH emphasis, targeting on the translation of near infrared (NIR) brain imaging to clinical assessment for children with cerebral palsy. Over ten million Americans are affected by central nervous system disorders that result in motor deficits. Cerebral palsy (CP) is the most common motor disorder of central origin in childhood and affects at least 2 children per 1000 live births every year . One of …

Influence Of Hypoxia, Hypercapnia And Inspiratory Efforts On Sympathoexcitation During Apnea, Vikram Rao

Bioengineering Theses - Archive

Obstructive Sleep Apnea (OSA) is characterized by frequent periods of apnea resulting in hypoxia, hypercapnia and fluctuations of intrathoracic pressure (inspiratory efforts). Hypoxia, hypercapnia and inspiratory efforts lead to stimulation of peripheral chemoreceptors, central chemoreceptors and baroreceptors, respectively, which in turn influence Muscle Sympathetic Nerve Activity (MSNA). We hypothesized that hypoxia and hypercapnia result in an elevated MSNA response, while inspiratory efforts result in a reduced MSNA response during apnea. To test the hypothesis, we determined the contributions of hypoxia (at 12% O2), hypercapnia (at 3% CO2) and inspiratory efforts (mueller maneuvers at 20 mmHg) to MSNA (using microneurographic techniques) …

A Novel Approach For Mri Image Classification And Image Retrieval, Ankit Vinod Master

Bioengineering Theses - Archive

OBJECTIVE: Classification of MRI image data based on its attribute characteristics is very important for storing the image data and its efficient retrieval. This project aims to find a solution to the problem of classification of the images that are stored on a hard drive and image retrieval from the image database with optimum automation in a user friendly way. METHOD: Matlab was used to create a software tool for image classification and, Java and SQL were used to create a software tool for image retrieval. RESULTS: Image classification tool could read multiple files, extract attribute values from the files …

A Design Aid For Determining Width Of Filter Strips, Michael G. Dosskey, M. J. Helmers, Dean E. Eisenhauer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Watershed planners need a tool for determining width of filter strips that is accurate enough for developing cost-effective site designs and easy enough to use for making quick determinations on a large number and variety of sites. This study employed the process-based Vegetative Filter Strip Model to evaluate the relationship between filter strip width and trap¬ping efficiency for sediment and water and to produce a design aid for use where specific water quality targets must be met. Model simulations illustrate that relatively narrow filter strips can have high impact in some situations, while in others even a modest impact cannot …

Preparing, Characterizing, On-Line Digital Image Processing Of Residence Time Distribution And Modeling Of Mechanical Properties Of Nanocomposite Foams, Siew-Yoong Lee

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

The objectives of this research were to prepare, characterize and to study the effects of organoclay and extrusion variables on the physical, mechanical, structural, thermal and functional properties of tapioca starch (TS)/poly(lactic acid) (PLA) nanocomposite foams. On-line digital imaging processing was used to determine residence time distribution (RTD). Adaptive neuro-fuzzy inference system (ANFIS) was used to model the mechanical properties of nanocomposite foams.

Four different organoclays (Cloisite 10A, 25A, 93A, 15A) were used to produce nanocomposite foams by melt-intercalation. The properties were characterized using Xray diffraction, scanning electron microscopy, differential scanning calorimetric, and Instron universal testing machine. The properties were …

Synthesis And Characterization Of Polyionic Hydrogels, Pooja Desai

Theses and Dissertations

In this study we describe novel polyionic dendrimer – PEG hydrogels for drug delivery. Hydrogels have a crosslinked insoluble network of polymer chains, which have found many applications including drug delivery and tissue regeneration. Dendrimers provide an ideal platform for drug delivery as they possess a well-defined highly branched nanoscale architecture with many reactive surface groups. Their highly clustered surface groups allow for targeted drug delivery and high drug payload to enhance therapeutic effectiveness. This study presented a new type of polyionic hydrogels based on dendrimers with potential applications in drug delivery and tissue engineering. Polyethylene glycol (PEG) with various …

Assessment Of Fifth Metatarsal Etiology, Daniel Reed

All Theses

The fifth metatarsal 'Jones Fracture' is a fracture that occurs 3.5cm distal to the tuberosity. It is an injury that is common in athletes, especially those who participate in sports with a lot of lateral movement. The Jones Fracture is known for its difficulty to heal due to non-union and re-fracture. There has been much research recently regarding in-shoe pressure distributions and their relation to shoe type, movement, and shoe surface interaction. However, only the forces along the bottom of the foot have been investigated. Literature and the direction of fracture seem to implicate a force on the lateral portion …