Biomedical Engineering and Bioengineering Commons^™

Estimating Fluid Local Velocity Within A Novel 3d Collagen Matrix Perfusion System, Ana M. Villanueva, Sherry L. Voytik, Kevin P. Buno

The Summer Undergraduate Research Fellowship (SURF) Symposium

Traditional cell culture, performed on flat surfaces under static conditions, does not accurately represent physiologic conditions. As an alternative, groups have applied interstitial fluid flow (0.1-2.0 µm/s) through a 3D cell-embedded extracellular matrix (ECM). Cells sense the flow via mechanotransduction, a process by which cells sense mechanical forces and resultantly respond with biochemical signaling. Previous work demonstrates enhanced cell morphogenesis under interstitial flow conditions. However, fluid flow is poorly described within these systems, stressing the need for a well-characterized 3D interstitial flow system. Understanding fluid mechanics within a perfusion system will help elucidate cellular response to flow-induced mechanical forces.

The …

Tumor-Microenvironment-On-Chip To Mimic Tumor Heterogeneity, Victoria Noe-Kim, Altug Ozcelikkale, Bumsoo Han

The Summer Undergraduate Research Fellowship (SURF) Symposium

Ductal Carcinoma In Situ (DCIS) is a non-invasive cancer that forms around breast milk ducts that can potentially progress into invasive breast cancer if untreated. Lack of models to study its diverse pathophysiology and differential response to treatments poses a challenge to develop standard treatment modalities with improved therapeutic outcomes. The traditional in vitro models such as cell monolayer are convenient but insufficient to represent the physiological characteristics of DCIS tumor microenvironment and often fail to predict clinical outcomes. The animal models effectively simulate the in vivo environment but also lack the ability to control the environmental parameters to match …

Quantification Of Lps Eluate From Coated Microelectrode Devices, Jahrane A. Dale, Janak Gaire, Kevin J. Otto

The Summer Undergraduate Research Fellowship (SURF) Symposium

Penetrating microelectrode arrays have a great potential to be used as control and communication interfaces for neuroprosthetics. A persistent obstacle in the clinical implementation of microelectrode arrays is the chronic degradation of these devices, putatively due to the foreign body response. Though researchers have studied the progression of the foreign body response and the effect of anti-inflammatory drugs on the efficacy of the implant, the exact biological mechanisms of implant degradation are not fully understood. To more closely investigate the effect of the foreign body response on device degradation, neuroinflammation can be exacerbated by coating dummy electrodes implanted into mice …

Nonlinear Optical Microscopy Of Murine Abdominal Aortic Aneurysm, Katherine E. Wilson, Alexa A. Yrineo, Amelia J. Adelsperger, Hilary D. Schroeder, Delong Zhang, Jesse Zhang, Chien-Sheng Liao, Frederick W. Damen, Ji-Xin Cheng, Evan H. Phillips, Craig J. Goergen

The Summer Undergraduate Research Fellowship (SURF) Symposium

Abdominal aortic aneurysm (AAA) is a cardiovascular disease characterized by dilation and weakening of the vessel wall. AAA rupture is responsible for approximately 14,000 deaths annually in the United States [1]. Nonlinear optical (NLO) microscopy presents new possibilities for analyzing AAA tissue samples from murine models. Common NLO techniques are two-photon excitation fluorescence (TPEF), which detects the intrinsic autofluorescent properties of elastin, and second-harmonic generation (SHG), which is specific for collagen fibrils. Elastin and collagen, two major extracellular matrix components, help the aortic wall withstand internal pressure. Murine AAAs were created through 1) subcutaneous continuous systemic infusion of angiotensin II …

Chronic Brain Stimulation Using Micro-Ecog Devices, Hayden C. Carney, Roy Lycke, Kevin J. Otto, Amelia A. Schendel, Justin Williams

The Summer Undergraduate Research Fellowship (SURF) Symposium

Recording and stimulating brain activity has had great success both as a research tool and as a clinical technique. Neural prosthetics can replace limbs, restore hearing, and treat disorders like Parkinson’s and epilepsy, but are relatively crude. Current neural prosthetic systems use penetrating electrodes to achieve high precision, but the invasive nature of these devices provoke a strong immune response that limits chronic use. (Polikov et al) In our study we evaluate micro-electrocortiographic (micro-ECoG) devices which sit under the skull and on the surface of the brain for stimulation over chronic timescales. We anticipate these devices with their less invasive …

Characterization Of Swelling Ratio And Water Content Of Hydrogels For Cartilage Engineering Applications, Emily E. Gill, Renay S.-C. Su, Julie C. Liu

The Summer Undergraduate Research Fellowship (SURF) Symposium

Due to the high prevalence of arthritis and cartilage-related injuries, tissue engineers are studying ways to grow cartilage tissue replacements. Resilin, an elastomeric protein found in insect cuticles, is known for its extraordinary resilience and elasticity. In previous studies, recombinant resilin-based hydrogels, or cross-linked protein networks, exhibited potential for use in cartilage tissue scaffolds. Our lab successfully developed resilin-based proteins with a sequence based on the mosquito gene and showed that resilin-based hydrogels possess mechanical properties of the same order of magnitude as native articular cartilage. In addition, these mechanical properties can be controlled by changing the protein concentration. To …

Design And Fabrication Of A Novel Electrospinning System For Musculoskeletal Tissue Regeneration, Carter L. Chain, Maggie R. Del Ponte, Meng Deng, Feng Yue, Shihuan Kuang

The Summer Undergraduate Research Fellowship (SURF) Symposium

Disease and injury to human tissue, especially musculoskeletal tissue, is a prevalent concern to the public, affecting millions of people each year. Current treatment options involving autografts and allografts are hindered by limited availability and risk of immunogenicity, respectively. In order to overcome these limitations, a transdisiplinary regenerative engineering strategy has emerged with a focus on the development of biomimetic scaffolds that closely mimic the properties of the native tissues. For example, the structure of muscle tissue is characterized by oriented muscle fibers. However, fabrication of aligned nanofiber structures that mimic the anisotropic organization of muscle presents significant engineering challenges. …

Wirelessly Powered And Transmitting Current Sensing Device, Christopher Quinkert, Steven Lee, Pedro Irazoqui

The Summer Undergraduate Research Fellowship (SURF) Symposium

As the rate of incidence of diabetes increases in the modern world, more accurate and reliable methods of glucose detection must be developed for patients with diabetes. Currently, 25.8 million people have diabetes in the United States alone and account for $174 billion in healthcare costs annually [1]. Devices that can be used without the need for as much patient interaction, regular replacement, or great patient expenses would be a large step forward in the ability of doctors and patients to effectively manage diabetes. To measure glucose concentrations in vivo, a biosensor is used to transduce glucose to an electrical …

The Role Of Metal Oxide Layers In The Sensitivity Of Lactate Biosensors Subjected To Oxygen-Limited Conditions, Elizabeth Andreasen, Lia Stanciu, Aytekin Uzunoglu

The Summer Undergraduate Research Fellowship (SURF) Symposium

Amperometric lactate biosensors are used to detect lactate concentration in blood and tissues, which is integral in identifying cyanide poisoning, septic shock, and athletic condition. The construction of lactate biosensors with high sensitivity, selectivity, and stability is imperative to diagnose and determine these medical conditions. Lactate detection is currently limited to oxygen-rich environments due to the fact that oxygen is a limiting factor in the lactate reaction. To circumvent this problem, researchers have developed mediators or alternate, oxygen-free enzymes to improve sensitivity. In our study, ceria (CeO₂) with high oxygen storage capacity (OSC) was introduced to the enzyme …

The Effects Of Chronic Neural Implantation On Localized Vasculature, Andrew L. Ready

Open Access Theses

Prosthetic solutions currently available range from simple devices intended for aesthetics purposes to complex systems attempting to restore lost function and sensation; of these methods, none show more promise in restoration of normal function and life satisfaction than neural prosthetics. These devices directly interface with the nervous system in order to restore realistic function and feeling to the patient, potentially returning them to how their life once was. While in some cases patients requiring prosthetics can utilize peripheral nerves, those who suffer from injuries or disease which cause damage to the central nervous system can necessitate the usage of devices …

Particle Swarm Optimization Using Multiple Neighborhood Connectivity And Winner Take All Activation Applied To Biophysical Models Of Inferior Colliculus Neurons, Brandon S. Coventry

Open Access Theses

Age-related hearing loss is a prevalent neurological disorder, affecting as many as 63% of adults over the age of 70. The inability to hear and understand speech is a cause of much distress in aged individuals and is becoming a major public health concern as age-related hearing loss has also been correlated with other neurological disorders such as Alzheimer's dementia. The Inferior Colliculus (IC) is a major integrative auditory center, receiving excitatory and inhibitory inputs from several brainstem nuclei. This complex balance of excitation and inhibition gives rise to complex neural responses, which are measured in terms of firing rate …

Standardizing The Collection And Measurement Of Glucose In Exhaled Breath And Its Relationship To Blood Glucose Concentrations, Mark Hamilton

Open Access Theses

Blood glucose level control (glycemic control) is crucial in diabetes. Limitations in current commercially available monitoring devices include causing patient pain leading to poor blood glucose level management. The development of a non-invasive measurement system may lead to improved patient glycemic control, reducing unwanted side-effects and complications of poor blood glucose level maintenance.

This work explores the use of glucose within exhaled breath in attempt to establish an indirect method of blood glucose level measurement. Specifically, exhaled breath condensate (EBC) is examined. A breath condensing unit was designed to measure the temperature of the system, flow rate, volume of expired …

Robust, Degradable Peg-Based Collagen Hydrogels For Elastomeric Tissue Augmentation, Charles Wilbur Peak

Open Access Theses

Vocal folds are made of an elastomeric tissue and are essential to everyday life, allowing for communication. Approximately 28 million individuals have paralysis or scarring of the vocal folds mostly due to injury or systemic diseases. Symptoms may include voice hoarseness or fatigue. Healthy vocal folds consist of distinct layers of soft tissue. We are designing hydrogels with properties similar to these healthy tissues. The hydrogels are envisioned to be used as injectable and degradable tissue matrices that allow for repair and regeneration of the vocal folds. ^ We present the synthesis of a robust and degradable hydrogel system made …

Developing An Embedded System Solution For High-Speed, High-Capacity Data Logging For A Size-Constrained, Low-Power Biomechanical Telemetry System And Investigating Components For Optimal Performance, Brandon Blaine Gardner

Open Access Theses

The Purdue Neurotrauma Group (PNG) seeks to develop a biomechanical telemetry system capable of monitoring and storing athletes' head motions with the intention of identifying when a player may be at risk of neurophysiological damage, especially brain damage. A number of commercially-available systems exist with a similar goal; however, each of these systems discards information below an acceleration threshold. Research by PNG indicates that any acceleration may contribute to brain damage and that, because of this, an event-based model is insufficient for a proper understanding of an athlete's neurophysiological health. Continuous-time monitoring of head accelerations is therefore necessary. To facilitate …

Characterizing Habituation Using The Time-On-Task Metric In An Iris Recognition System, Jacob A. Hasselgren

Open Access Theses

This thesis presents a characterization of biometric habituation in an iris recognition study using qualitative analysis of a distributed habituation survey and quantitative analysis of iris images collected in 2010 and 2012. The performed analyses answered the following two questions: a) How consistently does the biometric community define habituation?; and b) Does the time-on-task variable provide enough evidence to indicate the existence of habituation in an iris recognition system? The qualitative analysis examined responses to 12 habituation-related questions from 13 biometric experts to identify common themes that not only determined definition consistency but also characterized critical components often omitted from …

Controlling Protein Release Using Biodegradable Microparticles, Benjamin Patrick Kline

Open Access Theses

Research in the field of protein therapeutics has exploded over the past decade and continues to grow in both academia and in industry. Protein drugs have advantages of being highly specific and highly active making them coveted targets for high profile disease states like cancer and multiple sclerosis. Unfortunately, their many advantages are complemented by their obstacles. Because proteins are highly active and highly specific, the window between efficacy and toxicity is very narrow and drug development can be long and arduous. In addition, protein activity is dependent on its specific folding conformation that is easily disrupted by a variety …

Computer Modeling And Simulation Of Implantable Medical Device Heating Due To Mri Gradient Coil Fields, Bryan David Stem

Open Access Theses

For patients with implantable medical devices, the ability to safely undergo MRI scanning is critical to ensuring the highest standard of care. The gradient coils of an MRI generate kilohertz frequency, time varying magnetic fields. These magnetic fields induce a voltage on the external case of metallic, implantable medical devices through electromagnetic induction. Since the magnetic field generated by a gradient coil is time varying, the induced voltage results in the flow of eddy currents which can cause heating effects. These heating effects have been successfully modeled using ANSYS Maxwell and ANSYS Mechanical software packages.

The multi-physics simulation and solution …

Feasibility Of Pulsed Proton Induced Acoustics For 3d Dosimetry, Fahed M. Alsanea

Open Access Theses

Proton therapy has the potential to deposit its energy in tissue with high conformity to the tumor and significantly reduced integral dose to normal tissue compared to conventional radiation, such as x-rays. As a result, local control can be enhanced while reducing side-effects and secondary cancers. This is due to the way charged Particles deposit their energy or dose, where protons form a Bragg peak and establish a well-defined distal edge as a function of depth (range). To date, the dose delivered to a patient from proton therapy remains uncertain, in particular the positioning of the distal edge of the …

Developing A Hardware Platform For A Low-Power, Low-Cost, Size-Constrained Biomechanical Telemetry System, Aditya Balasubramanian

Open Access Theses

As sport-related traumatic brain injuries face increasing attention from the media and the general public, the need to be able to detect brain injury quickly, inexpensively and accurately is more important than ever. Commercially-available event-based systems exist that claim to achieve this goal; however, they collect little to no continuous-time data and primarily indicate when a pre-determined acceleration threshold has been exceeded under the unvalidated assumption that a potentially concussive blow has occurred. Recent findings by the Purdue Neurotrauma Group (PNG) have indicated that repeated exposure to both concussive and subconcussive blows can result in cumulative trauma disorder. To track …

Characteristics Of Fibrous Tissue At High Rates Of Tensile Loading, Benjamin J. Claus

Open Access Theses

The mechanical behavior of fibrous tissue is generally characterized at very low strain rates. However, many injuries occur at high rates of loading, such as those encountered in sporting events or vehicle accidents. An understanding of injury behavior requires the injury process to be recorded at high strain rates. Even at low rates of loading, the injury/failure within tissues occurs quickly. Furthermore, using conventional imaging systems, the surface of a specimen may be well documented throughout an experiment. However, damage formation does not necessarily begin at the surface of the specimen or even on the surface exposed to a camera. …

Biomechanics And Relaxivity For Functional Imaging Of Articular Cartilage Injury And Degradation, Kateri Elizabeth Fites

Open Access Theses

Osteoarthritis (OA) is a major debilitating health concern and economic burden worldwide, affecting 27 million people in the United States alone. OA often follows tissue injury, and is marked by changes in the structure and biomechanical function of cartilage, including breakdown of extracellular matrix molecules, loss of bulk tissue stiffness, and increase in articular surface friction and wear. Unlike bone and many other tissues, cartilage lacks an intrinsic capacity for regeneration. Advanced OA is typically diagnosed by patient symptoms (e.g. joint pain) and confirmed by radiographic evaluation of joint space narrowing. However, the application of functional imaging to assess cartilage …

A Compact Theory Of Magnetic Nerve Stimulation: Predicting How To Aim, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Background: A compact theory that predicts quantitatively when and where magnetic neurostimulation will occur is needed as a guide to therapy, ideally providing a single equation that defines the target volume of tissue excited by single or dual coils. Methods: A first-principles analysis of magnetic stimulation incorporating a simplified description of electromagnetic fields and a simplified cable theory of the axon yields a mathematical synthesis predicting how to aim. Results: Nerve stimulation produced by a single circular coil having one or more closely packed turns occurs in donut shaped volume of tissue beneath the coil. Axons spanning several millimeters are …

Noninvasive Measurement Of Cardiac Stroke Volume Using Pulse Wave Velocity And Aortic Dimensions: A Simulation Study, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Background: Concerns about the cost-effectiveness of invasive hemodynamic monitoring in critically ill patients using pulmonary artery catheters motivate a renewed search for effective noninvasive methods to measure stroke volume. This paper explores a new approach based on noninvasively measured pulse wave velocity, pulse contour, and ultrasonically determined aortic cross sectional area. Methods: The Bramwell-Hill equation relating pulse wave velocity to aortic compliance is applied. At the time point on the noninvasively measured pulse contour, denoted th, when pulse amplitude has fallen midway between systolic and diastolic values, the portion of stroke volume remaining in the aorta, and in turn the …

Choosing Inclusion Criteria That Minimize The Time And Cost Of Clinical Trials, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

AIM: To present statistical tools to model and optimize the cost of a randomized clinical trial as a function of the stringency of patient inclusion criteria. METHODS: We consider a two treatment, dichotomous outcome trial that includes a proportion of patients who are strong responders to the tested intervention. Patients are screened for inclusion using an arbitrary number of test results that are combined into an aggregate suitability score. The screening score is regarded as a diagnostic test for the responsive phenotype, having a specific cutoff value for inclusion and a particular sensitivity and specificity. The cutoff is a measure …

Synthesis And Characterization Of Nucleic Acid-Functionalized Nanomaterials, Brianna S. Carroll, Jong Hyun Choi

The Summer Undergraduate Research Fellowship (SURF) Symposium

Motor proteins such as kinesin move along microtubules in order to transport cellular cargos throughout the cell by obtaining energy from RNA hydrolysis which allows the cell to complete the tasks needed to stay alive. In this work, we developed synthetic molecular motors using DNA enzymes (DNAzyme) and fluorescent nanomaterials which mimic the functions and structures of motor proteins. A DNAzyme-capped CdS nanoparticle and a RNA-functionalized single-walled carbon nanotube (SWCNT) were used as a walker and a track in the motor platform, respectively. As a walking mechanism, the DNAzyme cleaved the RNA substrates in the presence of metal cations. The …

Bicistronic Design For Precise And Reliable Gene Expression, Nidhi N. Menon, Jenna Rickus

The Summer Undergraduate Research Fellowship (SURF) Symposium

Despite having progressed extensively in the field of synthetic biology in terms of DNA synthesis, analysis and transplanting, we still cannot reliably, quantitatively measure expression of new genetic constructs. We engineered a biobrick compatible expression cassette to control transcription and translation initiation which can be reused in new genetic contexts. Previous research has shown that the Bicistronic design have much lesser variations in expression with varying genes of interest as compared to the regular monocistronic design.(Mutalik, Endy, Guimaraes, Cambray, Lam, Juul, Tran & Paull, 2013) The Bicistronic design(BCD) consists of two Shine-Dalgarno sequences in its translation element which when combined …

In Vivo Flow Measurements Of Murine Renal Arteries And Veins With High Frequency Ultrasound, Amy E. Bogucki, Hilary D. Schroeder, Alexa A. Yrineo, Craig J. Goergen

The Summer Undergraduate Research Fellowship (SURF) Symposium

The number of glomeruli in the kidneys has been shown to have an effect on the decline in renal function over time (Brenner, Garcia, Anderson 1988). Furthermore, flow in the renal arteries and veins may depend on the number of glomeruli in the kidney. Consistent in vivo measurements of volumetric flow in the renal arteries and veins are difficult to obtain. Thus, the purpose of this study was to develop non-invasive imaging techniques capable of estimating arterial and venous flow to kidneys. A high-frequency small animal ultrasound system was chosen based upon its excellent spatial and temporal resolution when imaging …

Determination Of Master Compliance Curve For Extruded Semolina Pasta, Laura E. Emery, Martin Okos

The Summer Undergraduate Research Fellowship (SURF) Symposium

The dependence of the rate of relaxation of semolina pasta on moisture content and temperature and how it affects shrinkage during drying has not yet been determined. The purpose of this research was to develop an equation that relates moisture content and temperature in order to obtain a master curve for creep of the product. When found, this equation could help to optimize the drying process and increase the quality of the final pasta product. Semolina flour mixed with water and propionic acid to create a 35% wet basis product was extruded on a C.W. Brabender 2523 to obtain a …

Artificial Yeast Polarization Controlled By Chemical Gradient, James K. Nolan, Bernard Tao

The Summer Undergraduate Research Fellowship (SURF) Symposium

Engineering synthetic multicellular systems will lead to new synthetic biology technological platforms, inform developmental biology through recapitulation of natural systems and possibly unveil novel morphologies with practical applications not before reached throughout natural history (Maharbiz, 2012). Creating an exogenous molecular circuit that will polarize unicellular cells into “apical” and “basal” domains relative to a substrate plane would fulfill a missing component towards fully multicellular synthetic cellular communities (Maharbiz, 2012). To this end, a PIP₃ polarization network previously designed by Chau and associates (Chau, Walter, Gerardin, Tang, Lim 2012) was coupled to the specific activation by niacin of a recombinant …

The Efficacy And Optimization Of Somatosensory Intracortical Microstimulation In Rats, Sean P. Mcdowell, Ryan S. Verner, Kevin J. Otto Dr.

The Summer Undergraduate Research Fellowship (SURF) Symposium

Demand exists for brain-machine interfaces that offer a wide range of sensory feedback along with volitional motor control to individuals with limited control of natural sensory or motor function. As these sensorimotor devices are developed, it is necessary to improve the interaction between the prostheses and higher-level cortical structures. Optimizing these somatosensory stimulation parameters will require the use of a high-throughput experimental design. To address this, one Sprague-Dawley rat was trained to respond to auditory stimuli during a conditioned-avoidance behavior task and then implanted with a penetrating microelectrode array in the part of the somatosensory cortex corresponding to the left …