Biomedical Engineering and Bioengineering Commons^™

Pulsed Electric Field Ablation Of Esophageal Malignancies And Mitigating Damage To Smooth Muscle: An In Vitro Study, Emily Gudvangen, Uma Mangalanathan, Iurii Semenov, Allen S. Kiester, Mark A. Keppler, Bennett L. Ibey, Joel N. Bixler, Andrei G. Pakhomov

Bioelectrics Publications

Cancer ablation therapies aim to be efficient while minimizing damage to healthy tissues. Nanosecond pulsed electric field (nsPEF) is a promising ablation modality because of its selectivity against certain cell types and reduced neuromuscular effects. We compared cell killing efficiency by PEF (100 pulses, 200 ns–10 µs duration, 10 Hz) in a panel of human esophageal cells (normal and pre-malignant epithelial and smooth muscle). Normal epithelial cells were less sensitive than the pre-malignant ones to unipolar PEF (15–20% higher LD50, p < 0.05). Smooth muscle cells (SMC) oriented randomly in the electric field were more sensitive, with 30–40% lower LD50 (p < 0.01). Trains of ten, 300-ns pulses at 10 kV/cm caused twofold weaker electroporative uptake of YO-PRO-1 dye in normal epithelial cells than in either pre-malignant cells or in SMC oriented perpendicularly to the field. Aligning SMC with the field reduced the dye uptake fourfold, along with a twofold reduction in Ca²⁺ transients. A 300-ns pulse induced a twofold smaller transmembrane potential in cells aligned with the field, making them …

On The Pursuit Of Developer Happiness: Webcam-Based Eye Tracking And Affect Recognition In The Ide, Tamsin Rogers

Honors Theses

Recent research highlights the viability of webcam-based eye tracking as a low-cost alternative to dedicated remote eye trackers. Simultaneously, research shows the importance of understanding emotions of software developers, where it was found that emotions have significant effects on productivity, code quality, and team dynamics. In this paper, we present our work towards an integrated eye-tracking and affect recognition tool for use during software development. This combined approach could enhance our understanding of software development by combining information about the code developers are looking at, along with the emotions they experience. The presented tool utilizes an unmodified webcam to capture …

Quantifying Fibronectin Mechanical Properties Using Antibody-Mediated Optical Tweezing (Amot), Caleb Dalton

Theses and Dissertations

Despite decades of investigations into fibronectin (FN) fibrillogenesis, fibril mechanics remain unclear. One of the most important roles for FN fibrils is in the arena of cellular mechanotransduction. Numerous studies have demonstrated that cells sense and respond to the mechanical properties of their surroundings; since FN fibrils are a major constituent of the ECM that links cells to their surroundings, mechanotransduction cannot be fully understood without understanding the mechanical properties of FN fibrils. In this proposal, a novel biomechanical assay is developed to probe isolated FN fibrils and quantify their response to specific loading conditions. This will be accomplished by …

Computational Modeling Of Temporal Eeg Responses To Cyclic Binary Visual Stimulus Patterns, Connor M. Delaney

Theses and Dissertations

The human visual system serves as the basis for many modern computer vision and machine learning approaches. While detailed biophysical models of certain aspects of the visual system exist, little work has been done to develop an end-to-end model from the visual stimulus to the signals generated at the visual cortex measured via the scalp electroencephalogram (EEG). The creation of such a model would not only provide a better understanding of the visual processing pathways but would also facilitate the design and evaluation of more robust visual stimuli for brain-computer interfaces (BCIs). A novel experiment was designed and conducted where …

Advanced Modeling And Innovative Transcranial Magnetic Stimulation Coil Designs For The Treatment Of Neurological Disorders, Mohannad Tashli

Theses and Dissertations

Transcranial magnetic stimulation (TMS) is a safe, effective and non-invasive treatment for several mental and psychiatric disorders. TMS is an FDA approved treatment and is commonly applied to patients who do not respond to medications for the treatment of clinical depression, smoking cessation, obsessive-compulsive disorder and migraine. Recently, there has been an increase in the development of electromagnetic neuromodulation techniques targeted at enhancing the effectiveness of TMS devices for the treatment of mental diseases. In TMS stimulation, focality is an important factor which determines the specificity of the pulses induced in different brain tissues. The electromagnetic pulses must be confined …

Characterization And Decoding Of Speech Activity From Intracranial Signals, Pedram Zanganeh Soroush

Theses and Dissertations

Speech is the first and foremost means of human communication. Millions of people worldwide suffer from severe speech disorders due to neurological diseases such as amyotrophic lateral sclerosis (ALS), brain stem stroke, and severe paralysis. A speech neuroprosthesis that decodes speech directly from neural signals could dramatically improve life for these individuals. Recent studies have demonstrated that it is possible to decode and synthesize various aspects of acoustic speech directly from intracranial measurements of electrophysiological brain activity. For those who have completely lost the ability to speak, the objective is to synthesize acoustic speech directly from brain activity during imagined …

Unveiling Similarities And Differences Between Cutaneous And Ocular Melanomas, Abdallah Badou, Nour El Imane Issam Salah, Mohamed Elbelhadji

Health Sciences

Melanomas are outstandingly aggressive cancers, still their incidence is increasing. They can occur in the skin as cutaneous melanoma or in the eye as ocular melanoma. Their pathogenesis is generally similar; however, the prognosis of ocular melanoma patients is still poor, due to its special genetic profile and tumor microenvironment. Here we review the similarities and differences between cutaneous and ocular melanoma, with a focus on their prognostic significance, their molecular signature, and their tumor microenvironment, in order to understand the strategies adopted to escape immune response. Gathering and understanding available knowledge of melanomas and their specificities may help to …

Full Body Harness Design Modifications And Evaluation: A Senior Design Project, Martin Mead, Jordan Von Seggern

The Journal of Undergraduate Research

Full-body harness (FBH) is critical for the safe operation of industrial and recreational activities, from installing and maintaining infrastructure such as wind turbines to ziplining and mountaintop adventures. However, harness design remains in the proprietary information of companies with limited technical information available for improvements or readjustments to specialized applications. As the outcome of the Capstone project, the paper focuses on multiple technical aspects and the engineering processes for designing FBH for ziplining recreational users, from selecting and testing materials for operation in cold weather to improvements in design and manufacturing for user comfort. The project is guided by technical …

Modeling Of Transport In Anatomic Respiratory Airways: Applications In Targeted Drug Delivery And Airborne Pathogenic Transmissions, Mohammad Mehedi Hasan Akash

Electronic Theses and Dissertations

This thesis aims to explore the potential of improving the efficacy of drugs for treatment of viral infections by targeting the nasopharynx, which is commonly the first site of infection for many viral pathogens. Currently, intranasal sprays are used, but the standard protocol (“Current Use” or CU) results in suboptimal drug deposition at the nasopharynx. To address this issue, an “Improved Use” or, IU protocol has been proposed, which involves pointing the spray bottle at a shallower angle and aiming slightly towards the cheeks. The IU delivery is also robust to perturbations in spray direction, which highlights the practical utility …

Modeling Of The Chest Wall Response To Prolonged Bracing In Pectus Carinatum, Brandon Sargent, Katie Varela, Dennis Eggett, Emily Mckenna, Christina Bates, Rebeccah Brown, Victor Garcia, Larry Howell

Biomedical Engineering Faculty Scholarship

Pectus carinatum is a chest wall deformity that is often treated through the wearing of an external brace. The treatment of the deformity could benefit from a greater understanding of chest wall characteristics under prolonged loading. These characteristics are difficult to model directly but empirical studies can be used to create statistical models. 185 patients from 2018-2020 received bracing treatment. Data on the severity of the deformity, treatment pressures, and time of wear were recorded at the first fitting and all subsequent follow-up visits. This data was analyzed using a statistical mixed effects model to identify significant measures and trends …

A Label-Free Fiber Ring Laser Biosensor For Ultrahigh Sensitivity Detection Of Salmonella Typhimurium, Shi Qiu, Bin Liu, Yuankui Leng, Edward Fox, Xian Zhou, Binbin Yan, Xinzhu Sang, Long Long, Xingdao He, Jinhui Yuan, Gerald Farrell, Qiang Wu

Articles

The rapid detection of low concentrations of Salmonella Typhimurium (S. Typhimurium) is an essential preventive measure for food safety and prevention of foodborne illness. The study presented in this paper addresses this critical issue by proposing a single mode-tapered seven core-single mode (STSS) fiber ring laser (FRL) biosensor for S. Typhimurium detection. The experimental results show that the specific detection time of S. Typhimurium is less than 20 min and the wavelength shift can achieve -0.906 nm for an S. Typhimurium solution (10 cells/mL). Furthermore, at a lower concentration of 1 cell/mL applied to the biosensor, a result of -0.183 …

Difference In Bioimpedance Across The Knee In Un-Injured Young Adults, Patrick J. Atkinson, Theresa Atkinson, Allison Seeley, Seerut Dhillon

Mechanical Engineering Publications

Background

Knee injuries induce swelling and resolution of swelling may be a useful factor in identifying states of healing and time to return to sports activities. Recent work has suggested that bioimpedance can provide an objective measure of swelling following total knee arthroplasty (TKA) and therefore may also provide guidance for clinical decision-making following knee injury. This study measures knee bioimpedance in young, active people to help define baseline variability and factors that influence limb to limb differences.

Methods

Bioimpedance was measured via sensors placed at the foot/ankle and thigh, in positions similar to those suggested for monitoring post-TKA swelling. …

Integrating The Spatial Pyramid Pooling Into 3d Convolutional Neural Networks For Cerebral Microbleeds Detection, Andre Accioly Veira

CCAC Theses and Dissertations

Cerebral microbleeds (CMB) are small foci of chronic blood products in brain tissues that are critical markers for cerebral amyloid angiopathy. CMB increases the risk of symptomatic intracerebral hemorrhage and ischemic stroke. CMB can also cause structural damage to brain tissues resulting in neurologic dysfunction, cognitive impairment, and dementia. Due to the paramagnetic properties of blood degradation products, CMB can be better visualized via susceptibility-weighted imaging (SWI) than magnetic resonance imaging (MRI).CMB identification and classification have been based mainly on human visual identification of SWI features via shape, size, and intensity information. However, manual interpretation can be biased. Visual screening …

An Experimentally Validated Computational Model For The Degradation And Fracture Of Magnesium-Based Implants In A Chemically Corrosive Environment, Mark M. Ousdigian

Dissertations, Master's Theses and Master's Reports

In the orthopedic and cardiovascular fields there is a growing interest for biodegradable implants, which can be naturally degraded in the body environment over time so that no extraction surgery is required. These implants must be designed to maintain their strength until the fracture has healed in the body, which could be influenced by many factors such as -the patient’s age, activities, body weight, pre-existing conditions etc. Hence, an ideal implant design should be done on a patient-by-patient basis. In the present work, a computational model is developed to predict the degradation and fracture of magnesium-based implants in a stress-coupled …

การพัฒนาระบบตรวจวัดสารประกอบอินทรีย์ระเหยง่ายโดยใช้ชุดอุปกรณ์เพิ่มความเข้มข้นพร้อมการปรับเปลี่ยนอุณหภูมิ, พรภวิษย์ สินสุขอุดมชัย

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้มีวัตถุประสงค์เพื่อพัฒนาระบบตรวจวัดสารประกอบอินทรีย์ระเหยง่าย (Volatile organic compounds : VOCs) โดยใช้ชุดอุปกรณ์เพิ่มความเข้มข้น (Preconcentrator Array) ที่สามารถปรับเปลี่ยนอุณหภูมิได้ เพื่อให้สามารถเพิ่มความไว (sensitivity) และความจำเพาะ (selectivity) ในการตรวจวัดสาร VOCs ตัวอย่างที่มีหลายสารองค์ประกอบได้อย่างมีประสิทธิภาพ ระบบที่พัฒนาขึ้นนี้ได้นำสารดูดซับชนิดต่าง ๆ เช่น Tenax TA, Carbopack X และ CarboTrap B มาทดสอบใช้ โดยอาศัยรูปแบบของการให้อุณหภูมิและวิธีการวิเคราะห์ที่เหมาะสมเพื่อเพิ่มความแม่นยำในการตรวจวัดและการแยกแยะสารประกอบ VOCs ในตัวอย่างเป้าหมาย ในงานวิจัยนี้ได้ทำการออกแบบและพัฒนาระบบควบคุมความร้อนโดยใช้ไมโครคอนโทรลเลอร์ในการควบคุมการให้ความร้อนกับอุปกรณ์เพิ่มความเข้มข้น (Preconcentrator) จากนั้นได้ทำการทดสอบระบบที่พัฒนาขึ้นโดยทำการตรวจวัด VOCs ในสารตัวอย่างชนิดต่าง ๆ ที่ความเข้มข้นต่ำและวิเคราะห์ผลการวัดทดสอบด้วยการวิเคราะห์องค์ประกอบหลัก (Principal Component Analysis : PCA) จากผลการทดลองแสดงให้เห็นว่าระบบที่พัฒนาจากการใช้ชุดเพิ่มความเข้มข้นนี้สามารถตรวจวัดสาร VOCs ตัวอย่างที่เป็นตัวบ่งชี้ทางชีวภาพที่สำคัญของโรคโควิด-19 ได้อย่างมีประสิทธิภาพ นอกจากนี้ระบบที่พัฒนาขึ้นยังสามารถตรวจวัดสารตัวอย่างที่ประกอบด้วย VOCs ชนิดต่าง ๆ กันได้อย่างเหมาะสมเนื่องจากความสามารถในการเพิ่มความจำเพาะในการวัดของชุดอุปกรณ์เพิ่มความเข้มข้น ซึ่งระบบที่พัฒนาขึ้นในงานวิจัยนี้จะมีประโยชน์ในการประยุกต์ใช้ทางด้านการแพทย์และสาธารณสุข โดยเฉพาะอย่างยิ่งการตรวจคัดกรองโรคแบบไม่รุกล้ำและการตรวจวัดสาร VOCs ในสิ่งแวดล้อม

Development Of A Vascularized Osteogenic Implant Using Fused Glycosaminoglycan-Chitosan Microcapsules, Charles Michael Gabrion

Wayne State University Theses

Osteoarthritis remains a poorly treatable outcome of traumatic cartilage injury as cartilage is unable to self-repair. Unfortunately, roughly 10% of all adults in the United States have been diagnosed with osteoarthritis although the true fraction is likely at least 30%. While the main focus of osteoarthritis research has been on treating damage to the cartilage, osteoarthritis will also lead to damage to the adjacent trabecular bone due to wear via shearing down of the tissue’s surface. Considering this, in conjuncture with transplanted cartilages’ inability to integrate into the native tissue, unlike the surrounding bone, the significance of a combined osteochondral …

Zinc Oxide Based Nanomaterials And Device Designs - For Bioenergy Harvesting, Sensing And Water Purification, Congran Jin

Dartmouth College Ph.D Dissertations

Biomechanical energy harvested from the human body can power implantable electronics such as cardiac pacemakers, replacing conventional batteries and offering a lifelong energy solution. The electrical signals converted from biomechanical motions contain vital physiological information, making them suitable as a sensor to monitor one's health condition. Zinc Oxide (ZnO) is a versatile material with various intriguing properties, including piezoelectricity, photo-catalytic and piezo-catalytic properties. This thesis aims to exploit and enhance these properties of ZnO by rationally designing its nano- and micron-structures and employing them, along with other functional materials, in the development of novel biomechanical energy harvesting, water purification, and …

Development Of Technetium-99m Labeled Psma For Spect Prostate Cancer Imaging, Kalapaphuk Tachatumvitoon

Chulalongkorn University Theses and Dissertations (Chula ETD)

Technetium-99m (Tc-99m) is the most employed radionuclide in nuclear imaging diagnosis because of its ideal physiochemical properties and ready availability. It particularly suitable for Single Photon Emission Computed Tomography (SPECT), leading to cost-effective compared to other radionuclides. This study consists of two aims to expand the utilization of Tc-99m radiopharmaceutical for prostate cancer which is one of the highest incidence rates and mortality cancer among men. Currently, Tc-99m radiopharmaceutical for SPECT diagnosis is not clinically available for prostate cancer. Firstly, the new formulation for Tc-99m complexation with PSMA-617, a current ligand for radionuclide therapy of prostate cancer with lutetium-177 (Lu-177), …

Extraction, Quantification, Characterization, And Application In Food Packaging Of Chitin And Chitosan From Mushrooms: A Review, Buliyaminu A. Alimi, Shivani Pathania, Jude Wilson, Brendan Duffy, Jesus Maria Frias

Articles

The application of chitin in food systems is limited by its insolubility in some common solvents and poor degradability. Hence, it is deacetylated to obtain chitosan, an industrially important derivative with excellent biological properties. Fungal-sourced chitosan is gaining prominence and industrial attraction because of its superior functional and biological properties, and vegan appeal. Further, the absence of such compounds as tropomyosin, myosin light chain, and arginine kinase, which are known to trigger allergic reactions, gives it an edge over marine-sourced chitosan in food and pharmaceutical applications. Mushrooms are macro-fungi with a significant content of chitin, with many authors reporting the …

Biom 3010: Medical Measurements (Syllabus), Carl D. Herickhoff

Biomedical Engineering Syllabi Archive

Course Description: Theory and application of major types of sensors used in biomedical engineering and clinical medicine; principles of signal processing and instrumentation, such as frequency domain analysis, operational amplifiers, and filtration.