Biomedical Engineering and Bioengineering Commons^™

Improving The Stimulation Selectivity In The Human Cochlea By Strategic Selection Of The Current Return Electrode, Ozan Cakmak

Dissertations

The hearing quality provided by cochlear implants are poorly predicted by computer simulations. A realistic cochlear anatomy is crucial for the accuracy of predictions. In this study, the standard multipolar stimulation paradigms are revisited and Rattay’s Activating Function is evaluated in a finite element model of a realistic cochlear geometry that is based on µ-CT images and a commercial lead. The stimulation thresholds across the cochlear fibers were investigated for monopolar, bipolar, tripolar, and a novel (distant) bipolar electrode configuration using an active compartmental nerve model based on Schwartz-Eikhof-Frijns membrane dynamics. The results suggest that skipping of the stimulation point …

Angiogenic Supports For Microvascular Engineering, Zain Siddiqui

Dissertations

Ischemic tissue disease is caused by a lack of circulation / blood supply to tissue. This can be treated by introducing a number of angiogenic (pro-blood vessel forming) factors into the tissue. This work presents strategies for ischemic tissue treatment utilizing a novel proangiogenic self-assembling peptide hydrogel platform. To demonstrate the utility of this platform, its use alone as an angiogenic therapeutic (both alone as a self-assembling hydrogel and with two-component systems), and its ability to vascularize implants is explored. Due to these angiogenic scaffolds demonstrating efficacy to regenerate microvasculature, this work evaluates diseases that can be treated by the …

Emulating Future Neurotechnology Using Magic, Jay A. Olson, Mariève Cyr, Despina Z. Artenie, Thomas Strandberg, Lars Hall, Matthew L. Tompkins, Amir Raz, Petter Johansson

Psychology Faculty Articles and Research

Recent developments in neuroscience and artificial intelligence have allowed machines to decode mental processes with growing accuracy. Neuroethicists have speculated that perfecting these technologies may result in reactions ranging from an invasion of privacy to an increase in self-understanding. Yet, evaluating these predictions is difficult given that people are poor at forecasting their reactions. To address this, we developed a paradigm using elements of performance magic to emulate future neurotechnologies. We led 59 participants to believe that a (sham) neurotechnological machine could infer their preferences, detect their errors, and reveal their deep-seated attitudes. The machine gave participants randomly assigned positive …

Chitosan Oligosaccharides As A Nanomaterial Platform: Biological Properties And Applications In The Biomedical And Pharmaceutical Fields, Muhamad Alif Razi

Makara Journal of Science

Chitosan oligosaccharides (COS) have been introduced as marine-derived biomaterials with potential health benefits and good water solubility properties. This study presents an overview of the promising nanomaterial platform for biomedical and pharmaceutical applications of COS. The health benefits of COS, primarily their antioxidant and protective effects, anti-inflammatory activity, antidiabetic properties, and cholesterol-lowering effects are discussed. Furthermore, the promising recent articles on specific topics such as drug delivery systems and nanobiomaterials, are highlighted

Engineering The Development Of Neuromuscular Circuitry On-Chip, Inès Khiyara

Electronic Theses and Dissertations

Neuromuscular development happens in a complex interconnected network of biochemical pathways. This complicated embryonic development follows a strong, functional, and precise neuromuscular network that has interested both scientists and engineers who seek to better understand neuromuscular diseases. These disorders can be inherited or acquired, and their severity and mortality can vary. Researchers first studied the neuromuscular network from an organismal perspective, and more recently from an embryological, cellular, molecular, biochemical, and genetic perspective. From these studies, the fundamental principles of motor neuron pathfinding to muscles are widely understood, but the molecular drivers of specific nerve-muscle pairing remain unknown. Although in …

Advancing Fluorescent Contrast Agent Recovery Methods For Surgical Guidance Applications, Brook Kennedy Byrd

Dartmouth College Ph.D Dissertations

Fluorescence-guided surgery (FGS) utilizes fluorescent contrast agents and specialized optical instruments to assist surgeons in intraoperatively identifying tissue-specific characteristics, such as perfusion, malignancy, and molecular function. In doing so, FGS represents a powerful surgical navigation tool for solving clinical challenges not easily addressed by other conventional imaging methods. With growing translational efforts, major hurdles within the FGS field include: insufficient tools for understanding contrast agent uptake behaviors, the inability to image tissue beyond a couple millimeters, and lastly, performance limitations of currently-approved contrast agents in accurately and rapidly labeling disease. The developments presented within this thesis aim to address such …

Functionalized Plasmonic Nanostructures For Ultrasensitive Single Cell Analysis, Priya Rathi

Arts & Sciences Electronic Theses and Dissertations

Ultrasensitive detection and quantification of soluble, secreted and cell surface-bound proteins is critical for advancing our understanding of cellular systems, enabling effective drug development, novel therapies, and bio-diagnostics. However, exiting technologies are largely limited by their sensitivity, making the detection and quantification of low-abundant proteins extremely challenging. This forms a major barrier in various fields of biology and biomedical sciences. In this work, we introduce novel cellular analysis methodologies based on plasmon-enhanced fluorescence for analyzing cell structure and probing surface and secreted proteins from cells. In the first part, we introduce plasmon-enhanced expansion microscopy and demonstrate the effectiveness of employing …

Medical Foods For Lowering Homocysteine In Hypertensive Patients, Merrill F. Elias, Craig J. Brown

Maine-Syracuse Longitudinal Papers

In a recent commentary, Elias and Brown review the history of skepticism about the value of homocysteine for preventing hypertension and stroke. They argue that this skepticism is not supported by recent literature. This paper was stimulated by a recent comprehensive review of the literature on this topic by Smith and Refsum. Prior to these papers, a commentary and review by Skeete and DiPette provided evidence for the value of homocysteine-lowering in the treatment of hypertension. Elias and Brown supported this conclusion. Both papers emphasized that more work is needed to clarify the beneficial effects of lowering homocysteine.

Elias and …

Development Of A Crosslinked Osteochondral Xenograft And A Collagen Stabilizing Intra-Articular Injection To Remediate Cartilage Focal Lesions To Prevent Osteoarthritis, Mark Lewis Mosher

Theses and Dissertations

Osteoarthritis is one of the most common causes of disability in adults in America. It is a progressive and degenerative disease where the articular cartilage is broken down and lost from the surfaces of bones causing chronic pain and swelling in the joints, and currently has no cure. The most commonly osteoarthritis starts from a focal lesion on the cartilage surface, which will expand on the surface and downwards through the thickness of the tissue. The current gold standard for correcting cartilage focal lesions is the osteochondral autograft/allograft transplantation (OAT), which replaces the defect with a fresh osteochondral graft. The …

Oxidized Fibrin Alginate Microbeads To Treat Vascular Calcification, Brittany Nichole Macha

Theses and Dissertations

Calcification is linked to a high prevalence of cardiovascular events and mortality due to arterial stiffness. Stiffening of the arteries in the case of medial calcification is due to hydroxyapatite mineral deposited in the artery thus leading to the loss of elastin. A possibility of removing this rogue mineral along the vessel walls could be the use of osteoclasts. Osteoclasts, a type of osteocyte, have the unique ability to absorb bone in the bone turnover process. It is proposed that in the future, osteoclasts be delivered to the site of mineralization through oxidized alginate-fibrin microbeads. Alginate hydrogels have proven great …

Small-Separation Speckle Contrast Optical Spectroscopy For Intraoperative Assessment Of Parathyroid Glands Viability During Thyroid Surgery, Connor Berger

Symposium of Student Scholars

The parathyroid glands (PTGs) are often damaged during thyroid surgeries due to a lack of methods identifying PTGs and assessing their viability. Damage to PTGs can cause hypocalcemia, a deficiency of calcium in the body. This complication can lead to detrimental consequences with economic burden. The surgeon’s current method of viability assessment is qualitative and subjective. Our technical solution is to employ an optical technique called speckle contrast optical spectroscopy (SCOS) that noninvasively quantifies the blood flow index (Db) of biological tissues at deep tissue levels (>1cm). The goal of this project is to verify SCOS at small source-detector-separation …

Controlling Differentiation Of Adult Stem Cells Via Cell-Derived Nanoparticles: Implications In Bone Repair, Shruthi Polla Ravi, Yasmeen Shamiya, Aishik Chakraborty, Ali Coyle, Alap A. Zahid, Jin Wang, Michael Boutilier, Emmanuel Ho, Arghya Paul

Chemical and Biochemical Engineering Publications

No abstract provided.

Neurorretinitis Por Arañazo De Gato: A Propósito De Un Caso, Fernando Godín Estrada, Eduardo Enrique Cadena Galvis, Laura Alejandra Acevedo Espitia, Diana Valeria Rey-Rodríguez

Ciencia y Tecnología para la Salud Visual y Ocular

La enfermedad por arañazo de gato es una zoonosis distribuida por todo el mundo. En esa condición, los gatos son el reservorio primario de Bartonella henselae, siendo la pulga del gato (Ctenocephalides felis) el principal vector entre ellos. Dicha enfermedad se caracteriza por manifestaciones sistémicas predominantes en el cerebro, el ojo, el hígado, el bazo y el hueso. En este estudio se presenta el caso de una paciente femenina de 29 años, quien consultó por disminución de agudeza visual (AV) y dolor ocular pulsátil de intensidad 8/10, según la escala visual análoga (EVA) en el ojo izquierdo (OI), sin síntomas …

Six-Dimensional Single-Molecule Imaging With Isotropic Resolution Using A Multi-View Reflector Microscope, Oumeng Zhang, Zijian Guo, Yuanyuan He, Tingting Wu, Michael D. Vahey, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

Imaging of both the positions and orientations of single fluorophores, termed single-molecule orientation-localization microscopy, is a powerful tool for the study of biochemical processes. However, the limited photon budget associated with single-molecule fluorescence makes high-dimensional imaging with isotropic, nanoscale spatial resolution a formidable challenge. Here we realize a radially and azimuthally polarized multi-view reflector (raMVR) microscope for the imaging of the three-dimensional (3D) positions and 3D orientations of single molecules, with precisions of 10.9 nm and 2.0° over a 1.5-μm depth range. The raMVR microscope achieves 6D super-resolution imaging of Nile red molecules transiently bound to lipid-coated spheres, accurately resolving …

Color Resolved Cherenkov Imaging Allows For Differential Signal Detection In Blood And Melanin Content, Vihan A. Wickramasinghe

Dartmouth College Master’s Theses

Cherenkov imaging in radiation therapy allows a video display of the irradiation beam on the patient’s tissue, for visualization of the treatment. High energy radiation from a linear accelerator (Linac) results in the production of spectrally-continuous broadband light inside tissue due to the Cherenkov effect; this light is then attenuated by tissue features from transport and exits from the delivery site. Progress with the development of color Cherenkov imaging has opened the possibility for some level of spectroscopic imaging of the light-tissue interaction and interpretation of the specific nature of the tissue being irradiated. Generally, there is a linear relationship …

Lipids Affect The Diffusion Of Estradiol In Osteonal Bone, Nicholas Anthony Cimino

ETD Archive

In healthy osteonal bone, embedded osteocytes form an intercellular communication network through overlapping cell membrane extensions, possibly defining an overlooked and clinically relevant lipid-mediated transport pathway for nonpolar molecules. Previous techniques evaluating solute transport in cortical bone limit tissue analysis to microscale areas (less than 1 mm2) using tracers and assumptions that diminish clinical relevance, presenting the need for an improved method to evaluate solute diffusion in macroscale areas (greater than 1 mm2) of osteonal bone. A new diffusion system - constructed of glass and polytetrafluoroethylene - was designed and validated for this purpose, exhibiting minimal adsorption of solutes and …

Predictions Of Indentation Stiffness Of Musculoskeletal Regions Using Ultrasound, Sean Doherty

ETD Archive

Tissue indentation response is an important metric for understanding how different musculoskeletal regions respond to loading and is a function of the tissue’s form. Modem imaging techniques provide information about the internal structures of human tissue. Ultrasound remains one of the most common imaging techniques performed, given its portability and low costs. Prior work and data collection on 100 patients involved the collection of ultrasound images at eight different locations across the musculoskeletal extremities. Given the tissue structure information that the medical imaging provided, it was hypothesized that the mechanical properties of the tissue could be predicted from this data. …

An Integrated Electronic-Skin Patch For Real-Time And Continuous Monitoring Of A Panel Of Biomarkers Combined With Drug Delivery, Tanzila Noushin

Electrical Engineering Theses

Inflammatory biomarkers present in the human body play a vital role in medical field by guiding the clinician in decision-making for many diseases. The levels of these inflammatory biomarkers are associated with the severity and progress of several diseases. Researchers have found that increasing severity of many diseases such as cardiovascular disease, after surgery infection, and adverse clinical outcomes due to infectious diseases, results in the elevation of the level of inflammatory biomarkers in human sweat. Furthermore, the inflammatory cytokines indicate the pathophysiology and prognosis of critically ill SARS‑CoV‑2 patients. In this thesis work, different sensors have been developed for …

Dendrimer-Based Drug Delivery Systems: History, Challenges, And Latest Developments, Juan Wang, Boxuan Li, Li Qiu, Xin Qiao, Hu Yang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Since the first dendrimer was reported in 1978 by Fritz Vögtle, dendrimer research has grown exponentially, from synthesis to application in the past four decades. The distinct structure characteristics of dendrimers include nanoscopic size, multi-functionalized surface, high branching, cavernous interior, and so on, making dendrimers themselves ideal drug delivery vehicles. This mini review article provides a brief overview of dendrimer's history and properties and the latest developments of dendrimers as drug delivery systems. This review focuses on the latest progress in the applications of dendrimers as drug and gene carriers, including 1) active drug release strategies to dissociate drug/gene from …

In Vitro Bioreactor For Mechanical Control And Characterization Of Tissue Constructs, Samuel Coeyman

All Dissertations

Heart failure (HF) currently affects over 6 million Americans, 50% of whom die within 5 years of their initial diagnosis. A major contributor to the onset of HF is cardiac fibrosis in the myocardium, which arises when fibroblasts (FBs) are activated in response to heightened mechanical stress from overload conditions like hypertension. Activated FBs remodel the extracellular matrix (ECM) and secrete ECM proteins including collagen. FB remodeling has been studied in the past by applying forces and/or deformations to three-dimensional, cell-seeded gels and tissue constructs in vitro. Unfortunately, previous stretching platforms have traditionally not enabled mechanical property assessment to be …

Development Of A Tissue Engineered Cardiac Patch, Howard Herbert

All Dissertations

Cardiovascular Disease(CVD) is the leading cause of mortality in the developed world. CVD is most commonly manifested as atherosclerosis of the coronary arteries leading to Myocardial Infarction(MI). After MI, fibrosis of the ventricular wall leads to heart failure(HF), a pandemic affecting 26 million people globally. While therapies are continuously developed to combat HF, the treatment of choice, whole heart transplant, is limited by the availability of donor hearts. It is clear that there is a need to develop a long-term solution to combat HF and its enormous economic burden. Tissue Engineering and Regenerative Medicine holds promise as a possible solution …

Increasing Production Of Therapeutic Mabs In Cho Cells Through Genetic Engineering, Charles Barentine

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Between 2014 and 2018, the global market for therapeutic monoclonal antibodies (mAbs) rose from $60 billion to $115.2 billion with a projected value of $300 billion by 2025. These molecules are used to effectively treat some of the most challenging illnesses from auto-immune diseases to cancer. While mAbs are highly valuable with potent applications, their production at scale remains an outstanding challenge. These molecules are largely produced in Chinese Hamster Ovary (CHO) cells that require highly specific conditions to produce a useful product.

Genetic engineering presents one solution to overcome productivity limits. With the advent of CRISPR (clustered regularly interspaced …

Low Resource Assay For Tracking Sars-Cov-2 In Wastewater, Julissa Van Renselaar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wastewater based epidemiology (WBE) allows for the tracking of nucleic acid of SARS-CoV-2 in wastewater which gives the opportunity for the public and government officials to be informed about the infectivity of the virus in a community. Advances have been made in WBE that have allowed for higher performance, lower resource use, and faster turnaround time. An adapted concentration method of spin column direct extraction has yielded a proxy virus recovery of 83%, consumable cost of $2.01 per sample, and a turnaround time of 0.33 hour/sample. Other concentration methods have lower proxy virus recoveries, comparable cost, and comparable turnaround time. …

Enhancing Human Schwann Cells Reparative Behavior Using Heparin/Collagen Layer-By-Layer Coatings, Luis Carlos Pinzon-Herrera

Graduate Theses and Dissertations

When a peripheral nerve injury (PNI) occurs, the gold standard for tissue regeneration is the use of autografts. However, due to the secondary effects produced by multiple surgeries involved in the removal and implantation of autografts for very small lesions, it is possible to replace them with the use of Nerve Guide Conduits (NGCs). However, NGCs are limited to short lesions (less than 1 cm). This limitation is caused by the absence of compounds in the extracellular matrix (ECM) that autografts can provide. Since much of the regenerative process takes place on the NGC surface, our work aims to modify …

Tibial Compression During Activities Of Daily Living In Young And Older Adults, Elijah Miles Walker

Boise State University Theses and Dissertations

Introduction: Stress fracture, particularly in the tibia, is a growing concern among older adults (greater than 65 years). Older adults may have inherent stress fracture risk from ageing-related changes to their musculoskeletal system. Specifically, older adults reduced ankle neuromuscular function may impair their ability to attenuate repetitive compressive forces experienced during daily locomotor tasks and increase the likelihood of suffering bone damage from decreased bone tissue elasticity. Yet, it is currently unknown if older adults exhibit greater tibial compression than their younger counterparts during locomotor tasks. Purpose: This study sought to quantify tibial compression for older and younger adults when …

Image-Based Cancer Diagnosis Using Novel Deep Neural Networks, Hosein Barzekar

Theses and Dissertations

Cancer is the major cause of death in many nations. This serious illness can only be effectivelytreated if it is diagnosed early. In contrast, biomedical imaging presents challenges to both clinical institutions and researchers. Physiological anomalies are often characterized by modest modifications in individual cells or tissues, making them difficult to detect visually. Physiological anomalies are often characterized by slight abnormalities in individual cells or tissues, making them difficult to detect visually. Traditionally, anomalies are diagnosed by radiologists and pathologists with extensive training. This procedure, however, demands the participation of professionals and incurs a substantial expense, making the classification of …

The Role Of Generative Adversarial Networks In Bioimage Analysis And Computational Diagnostics., Ahmed Naglah

Electronic Theses and Dissertations

Computational technologies can contribute to the modeling and simulation of the biological environments and activities towards achieving better interpretations, analysis, and understanding. With the emergence of digital pathology, we can observe an increasing demand for more innovative, effective, and efficient computational models. Under the umbrella of artificial intelligence, deep learning mimics the brain’s way in learn complex relationships through data and experiences. In the field of bioimage analysis, models usually comprise discriminative approaches such as classification and segmentation tasks. In this thesis, we study how we can use generative AI models to improve bioimage analysis tasks using Generative Adversarial Networks …

Mango Surface Color Features Measurement Using Digital Image Processing, Md Towfiqur Rahman, Goutom Kumar, Md Abdul Momin

Biological Systems Engineering: Papers and Publications

Summary

Postharvest processing of agricultural produce is still done the conventional way in Bangladesh. Manual grading of agricultural produce, especially fruits and vegetables, is laborious and costly due to acute shortage of labor during the peak season, as well as difficulty maintaining the product quality. Machine vision system (MVS) applications are widely used nowadays as a non-destructive and cost-effective technology for automatically grading and sorting large volumes of produce in the packing house according to size, shape, color, texture, and surface defects. In this study, a simple MVS was constructed measuring different color features of mango fruit surface as a …

Development Of Optical Coherence Tomography Angiography System For Mouse Eye Imaging And Measurement Of Vasodilation, Yilin Li

McKelvey School of Engineering Theses & Dissertations

Optical coherence tomography angiography (OCTA) is broadly known as a non-invasive technology that allows examining the retinal and choroidal vasculatures, alternative to fluorescein angiography. In this study, we have developed an optical coherence tomography (OCT) system for imaging the mouse eye. We measure the retinal thickness, which is 216.53um. We apply OCTA to characterize the quantitative change in vessel diameter and the perfusion density of the retina after the wild-type mice are administered the adenosine or inhale carbon dioxide. Comparing the images acquired one minute and 5 minutes after the injection or CO₂ inhalation with the baseline, distinct changes …

Computational Fluid Dynamics Modeling Of Hemodialysis In Patients With An Arteriovenous Fistula, Maximilian Roth

McKelvey School of Engineering Theses & Dissertations

With the advent of arteriovenous fistula (AVF) for use in hemodialysis, the anastomosis built for such use has become a central point of the study to understand the flow and wall shear stresses in such a system since very large wall shear stresses can lead to arterial/vein rupture. Considering the commonly used creation site of an anastomosis as connecting the radial artery to the cephalic vein, a model is created to calculate the wall shear stresses across various components of the system. The model depicts a connection of the specified vein and artery bridged together allowing the increase in blood …