Biomedical Engineering and Bioengineering Commons^™

Nature-Inspired Material Strategies Towards Functional Devices, Sayantan Pradhan

Theses and Dissertations

Naturally sourced, renewable biomaterials possess outstanding advantages for a multitude of biomedical applications owing to their biodegradability, biocompatibility, and excellent mechanical properties. Of interest in this dissertation are silk (protein) and chitin (polysaccharide) biopolymers for the fabrication of functional biodevices. One of the major challenges restricting these materials beyond their traditional usage as passive substrate materials is the ability to combine them with high-resolution fabrication techniques. Initial research work is directed towards the fabrication of micropatterned, flexible 2D substrates of silk fibroin and chitin using bench-top photolithographic techniques. Research is focused on imparting electrochemical properties to silk proteins using conducting …

Imaging Potential In Saturation Recovery Methods For Sarcoidosis Patients With Medical Devices, Samantha Zhao

Theses and Dissertations

Cardiovascular magnetic resonance (CMR) imaging is a preferred imaging methodology due to its lack of ionizing radiation and ability to detect myocardial inflammation and fibrosis using quantitative T1 mapping techniques. Cardiac sarcoidosis (CS) is characterized as the formation of granulomas in the myocardium. Current methods for detection include measuring non-cardiac specific C-reactive protein (CRP) levels, or PET imaging, which uses ionizing radiation, therefore CMR would make an ideal imaging option. However, many CS patients have implanted cardiac devices which can cause degradation in image. The modified Look-Locker inversion recovery (MOLLI) method is widely used in quantitative T1 mapping with high …

Estimating Affective States In Virtual Reality Environments Using The Electroencephalogram, Meghan R. Kumar

Theses and Dissertations

Recent interest in high-performance virtual reality (VR) headsets has motivated research efforts to increase the user's sense of immersion via feedback of physiological measures. This work presents the use of electroencephalographic (EEG) measurements during observation of immersive VR videos to estimate the user's affective state. The EEG of 30 participants were recorded as each passively viewed a series of one minute immersive VR video clips and subjectively rated their level of valence, arousal, dominance, and liking. Correlates between EEG spectral bands and the subjective ratings were analyzed to identify statistically significant frequencies and electrode locations across participants. Model feasibility and …

Effect Of Stimulus Waveform On Transcranial Magnetic Stimulation Metrics In Proximal And Distal Arm Muscles, Christopher Lynch

Theses and Dissertations

Objectives: The purpose of this study was to determine the effect of common transcranial magnetic stimulation (TMS) waveforms (monophasic and biphasic) on resting motor threshold (RMT), active motor threshold (AMT), and motor evoked potential (MEP) amplitudes in the biceps and first dorsal interosseous (FDI) because waveforms may affect motor targets differently. Additionally, we determined the test-retest reliability of TMS metrics for each stimulation type and muscle.

Methods: Ten individuals participated in two sessions of single-pulse TMS delivered to the motor cortex perpendicular to the central sulcus. MEPs were normalized to the maximum EMG signal during contraction and were recorded at …

Complementary Techniques To Study The Behavior Of Water And The Effect On Diffusion And Degradation In Hydrogels, Paige Rockwell

Master’s Theses

Hydrogels exhibit biocompatibility in a range of biomedical applications, including drug delivery. This thesis aims to develop complementary techniques to measure the diffusion and degradation behaviors within an injectable, hydrolytically degradable hydrogel, formed via the covalent crosslinking of ethoxylated trimethylolpropane tri-3- mercaptopropionate (ETTMP) and poly(ethylene glycol) diacrylate (PEGDA), to determine its suitability as a drug delivery matrix. The characterization of water as either free, within the network openings of the hydrogel, or bound, tightly associated with the polymer chains, was determined using differential scanning calorimetry (DSC). The mobility of each type of water within the hydrogels was determined via nuclear …

Improved Biochar Based Controlled-Release Nitrogen Fertilizers For Sustainable Corn Production, Robiul Islam Rubel

Electronic Theses and Dissertations

Nitrogen use efficiency (NUE) is an essential factor to increase crop yield. When conventional nitrogen fertilizer (e.g. Urea, Ammonium Sulphate, etc.) is applied in the field, generally over 50% of the N of these fertilizers may lose into the air due to vaporization, or run-off and leaching in rivers and lakes. The N losses lead to not only low NUE but also serious environmental problems. The consequence of N losses results in insufficient N available to meet the demand of crop growth at the growing stages. Lack of sufficient N for crop growth puts a threat of nutrient deficiency and …

Engineering Thermostable Regulators For Inducible Gene Expression In Thermophiles, Connor M. Joyce

Honors Theses and Capstones

Thermophilic bacteria have attracted research interest due to their ability to grow at high temperatures ranging from 45 °C to 75 °C with some extreme thermophiles able to survive nearly boiling temperatures. They are valuable sources of thermostable biocatalysts and many have great potential as industrial hosts for biofuel production because fermentation at high temperatures has advantages such as reduced processing costs and lower risk of contamination compared with mesophilic bacteria. For example, some Geobacillus species has been shown to have high solvent tolerance, making them good candidates as host for alcohol production. To develop them as industrial hosts, large …

Injectable Gelatin-Silk Fibroin Composite Hydrogels For In Situ Cell Encapsulation, Ryann D. Boudreau

Honors Theses and Capstones

Hydrogels are widely used tools for tissue engineering and regenerative medicine. Characterized as biofunctional, water-based polymer matrices with tunable mechanical properties, hydrogels have promising but limited applications in biomedical engineering, due to poor and static matrix strength. Here we plan to rectify this issue by introducing a new hydrogel made from a composite of gelatin and silk fibroin crosslinked by microbial transglutaminase (mTG) instantly and beta sheet formation gradually, respectively. This interpenetrating network (IPN) shows enhanced mechanical stiffness and strength compared to gelatin hydrogels, and is capable of encapsulating human cells with high viability demonstrated by the encapsulation of human …

A Step Closer To Elastogenesis On Demand; Inducing Mature Elastic Fibre Deposition In A Natural Biomaterial Scaffold, Francisco R. Almeida-González, Arlyng González-Vázquez, Suzanne M. Mithieux, Fergal J. O'Brien, Anthony S. Weiss, Claire Brougham

Articles

Elastic fibres play a key role in bodily functions where fatigue resistance and elastic recovery are necessary while regulating phenotype, proliferation and migration in cells. While in vivo elastic fibres are created at a late foetal stage, a major obstacle in the development of engineered tissue is that human vascular smooth muscle cells (hVSMCs), one of the principal elastogenic cells, are unable to spontaneously promote elastogenesis in vitro. Therefore, the overall aim of this study was to activate elastogenesis in vitro by hVSMCs seeded in fibrin, collagen, glycosaminoglycan (FCG) scaffolds, following the addition of recombinant human tropoelastin. This combination …

Intrabodies Reveal Critical Steps Involved In Ricin's Interactions With The Ribosome, Timothy Francis Czajka

Legacy Theses & Dissertations (2009 - 2024)

Ricin is a highly lethal protein toxin derived from the seeds of the castor plant, Ricinus communis. It is a Type II ribosome inactivating protein (RIP), meaning it is a heterodimer with one subunit, ricin toxin B (RTB), that mediates cell surface attachment and intracellular trafficking and a second subunit, ricin toxin A (RTA), that irreversibly shuts down protein synthesis in the cytosol. During trafficking, RTA and RTB necessarily separate in the endoplasmic reticulum, wherein RTA unfolds and translocates into the cytosol where it refolds into an enzymatically active conformation. RTA is remarkably fast acting and efficient, with few molecules …

Mapping Of Auditory Cortical Functions Using Electrocorticography, James Robert Swift

Legacy Theses & Dissertations (2009 - 2024)

Communication is a dynamic process through which we translate our inner thoughts in such a way that they can be shared with another person. This complex neurological phenomenon is a key predictor of our productivity and health. When our ability to communicate is compromised, our quality of life suffers. Although numerous methods to investigate the neuroscientific underpinnings of human language exist, our understanding of this process remains incomplete. Improving our understanding of where, when, and how auditory cortical activity occurs can enhance diagnostic techniques and improve treatment methods for neurological conditions that can impact auditory processing, such as epilepsy, or …

Assessing Midbrain Abnormalities In Parkinson’S Disease Using Magnetic Resonance Imaging, Kiarash Ghassaban

Wayne State University Dissertations

Diagnosing early-stage Parkinson’s disease (PD) and its manifestations is still a clinical challenge. Previous imaging studies using iron, neuromelanin (NM) and the Nigrosome-1 (N1) measures in the substantia nigra (SN) by themselves have been unable to provide sufficiently high diagnostic performance for these methods to be adopted clinically. In this dissertation, we start by studying idiopathic PD patients at their intermediate stages of the disease to evaluate the role of global and regional iron in the major deep gray matter nuclei. Then, we only focus on the NM complex in the midbrain and how neuronal loss interact with iron overload …

Als-Induced Excitability Changes In Individual Motorneurons And The Spinal Motorneuron Network In Sod1-G93a Mice At Symptom Onset, Christiana S.I. Draper

Browse all Theses and Dissertations

Amyotrophic lateral sclerosis (ALS) is the most common motorneuron (MN) disease in adulthood. ALS is hallmarked by the progressive loss of MNs in the brain, brainstem, and spinal cord. Many hypotheses to explain the pathogenesis of ALS have been explored, but the exact mechanisms underlying the development of this disease remain unknown. However, abnormalities in MN excitability and glutamate excitotoxicity are the most widely studied. For decades, researchers have examined MN excitability in ALS, but the current literature is inconsistent, showing evidence of hyperexcitability, hypoexcitability, or no change in excitability of MNs in ALS. Many of these studies also focus …

Applied Machine Learning In Extrusion-Based Bioprinting, Shuyu Tian

Theses and Dissertations

Optimization of extrusion-based bioprinting (EBB) parameters have been systematically conducted through experimentation. However, the process is time and resource-intensive and not easily translatable across different laboratories. A machine learning (ML) approach to EBB parameter optimization can accelerate this process for laboratories across the field through training using data collected from published literature. In this work, regression-based and classification-based ML models were investigated for their abilities to predict printing outcomes of cell viability and filament diameter for cell-containing alginate and gelatin composite hydrogels. Regression-based models were investigated for their ability to predict suitable extrusion pressure given desired cell viability when keeping …

Using A Lubricin Reporter Cell To Test Current Vs. Optimized Media Compositions, Sean M. Kennedy

Honors Undergraduate Theses

Osteoarthritis is a joint disease characterized by the breakdown of articular cartilage. The field of tissue engineering is interested in developing methods to produce biological alternatives to current orthopedic procedures. Lubricin is a molecule which is important in the proper lubrication of articular cartilage. It is a challenge in the field of tissue engineering to produce cartilage with sufficient lubricin expression. Developing a reporter cell for lubricin allowed for a more efficient investigation of the conditions wh­­­ich may influence its expression. By comparing "optimized" and traditional media solutions, it was determined that the use of a previously reported type II …

Workspace And Kinematic Modeling And Analysis Of Semi-Robotic Laparoscopic Surgery, Immanuel E. Girgis

Honors Undergraduate Theses

Laparoscopic Surgery has been revolutionized by the world of Surgical Robotics. Robot-Assisted Surgeries have been proven to have many advantages over the fundamental, traditional "by-hand" procedures previously conducted, and still currently being done for certain operations. Robot-assisted surgery may offer benefits to patients through the use of minimally invasive techniques, which may result in reduced blood loss, reduced blood transfusion, fewer complications, reduced postoperative pain, shorter hospital stays, and reduced recovery times (Ho et al., 2011). Studies have proven that robotic surgery may lead to patients recovering faster depending on the timeframe and the type of procedure (Tang et al., …

Biom 2720: Experimental Design And Analysis For Biomedical Engineering (Syllabus), Stephen Strain

Biomedical Engineering Syllabi Archive

Course Description: Application of probability, statistics, error analysis, uncertainty in design and performance of biomedical engineering experimentation; discussion and evaluation of common experimental designs for medical device development.

Novel Tools For Analysis Of Disordered Sleep And Motor Behavior In Preclinical Models Of Disease, Dillon M. Huffman

Theses and Dissertations--Biomedical Engineering

Subtle changes in sleep architecture can accompany and be symptomatic of various diseases or disorders. Understanding the complex interactions between sleep and health requires the ability to characterize sleep, probe its underlying mechanisms through perturbation, and quantify dependent physiological outcomes. Rodent models have come to be accepted as a valuable tool for preclinical investigations. However, experimental tools to accomplish such research typically rely on laborious methods that limit throughput and flexibility. Thus, research tools that minimize workload could be of great value to the research community and expedite investigation of the underlying mechanisms of sleep and further the development of …

Changes In Cardiovascular, Respiratory, And Neural Activity By Music: Effects Of Breathing Pathway On Feeling Emotions, Mohammad Javad Mollakazemi

Theses and Dissertations--Biomedical Engineering

Listening to music can induce emotional and physiological changes. Increasing recognition of the palliative effects of music has led to its use as an adjuvant therapeutic tool in the treatment of various diseases. It is also well known that autonomic nervous activities and some cardiorespiratory rhythms change in correspondence with music. However, less is known about how these effects triggered by music come about. Listening to music affects synchronization between electroencephalograms (EEGs) and cardiac rhythmic activity. This interaction between cardiac and electrical responses led us to investigate whether EEG segments synchronized to different portions of the cardiac cycle can better …

Facilitating Analysis Of Toxoplasma Gondii Bradyzoite Metabolic Activity Via Image Processing And Multivariate Logistic Regression For High Throughput Classification Of Mitochondrial Morphologies, Brooke Place

Theses and Dissertations--Biomedical Engineering

Approximately a third of the population worldwide is chronically infected by the parasite Toxoplasma gondii. During chronic infection the parasite resides within tissue cysts as the poorly understood bradyzoite form. Observation of these bradyzoites via microscopic imaging within tissue cyst purified from infected mouse brains has shown metabolic activity with heterogeneous replication potential. With fluorescence microscopy imaging targeting the parasite’s actively respiring mitochondria, the parasite’s metabolic state can be further investigated as the morphology of mitochondria can be associated with specific physiologic states. However, manually classifying mitochondrial morphologies from these images can be tedious and prone to error as …