Biomedical Engineering and Bioengineering Commons^™

Using Noninvasive Calibrated Cuff Plethysmography To Observe The Effects Of Cold-Water Immersion On Arterial Compliance, Rita M. Grigorian

Master's Theses

As the prevalence of cardiovascular diseases continues to exponentially grow in populations across the globe, the necessity of determining underlying factors, effective methods of diagnoses, and universally available preventive measures also grows. Early detection of endothelial dysfunction, a proven precursor of cardiovascular diseases, can be extremely impactful in encouraging preventative measures and early intervention before medical conditions become chronic. In recent years, ice plunging, a form of cryotherapy involving full body immersion in cold water, has gained popularity within circles of fitness and health practitioners, gaining the interest of people of all backgrounds. Certain parallels observed between the human physiological …

Modeling Of Patient-Specific Periaortic Mechanics And Pulmonary Artery Hemodynamics Based On Phase-Contrast Magnetic Resonance Imaging Sequences., Johane H. Bracamonte

Theses and Dissertations

Inverse modeling in cardiovascular medicine is a collection of methodologies that can provide non-invasive patient-specific estimations of clinical risk factors using medical imaging as inputs. Its incorporation into clinical practice has the potential to improve diagnosis and treatment planning with low associated risks and costs.

Herein, three different phase contrast magnetic resonance imaging (MRI) modalities were implemented as input data, displacement encoding with stimulated echoes (DENSE MRI) applied, and time-resolved velocity encoding phase-contrast MRI, in 1D and 3D, applied to pulmonary artery (PA) hemodynamics.

A model to account for the effect of periaortic interactions due to static and dynamic structures …

Left Atrial Appendage Printing Process, Areli Reyes, Brandon James Mukai, Mia Noelle Von Knorring

Biomedical Engineering

The left atrial appendage senior design team aims to assist in closing off the left atrial appendage that is susceptible to coagulation due to non-valvular atrial fibrillation. Coagulation in the left atrial appendage (LAA) can be life threatening as it can lead to a stroke. Dr. Chris Porterfield performs a procedure that uses the Boston Scientific Watchman to close the appendage. He finds that sizing the Watchman properly is difficult with limited visuals from live CT scans. He proposed converting the CT scans into a 3D printed model of the left atrial appendage and left atrium so he can visually …

A Study Of Acoustically Activated Nanodroplets, Songita Choudhury

Theses & Dissertations

Current treatment of acute myocardial infarction (AMI), which is the main pathophysiological event leading to death in the United States, has advanced considerably with the introduction of emergent percutaneous interventions, but there remains an urgent need for novel techniques to rapidly and accurately detect infarcted or ischemic tissue that results from AMI. Ultrasound contrast agents, also known as microbubbles (MB), have become commonplace in echocardiography. However, MBs are purely intravascular tracers and unable to cross endothelial barriers due to size. The limitations of MBs, namely size and short circulation times within the human body, led to the development of phase-change …

Extraction And Analysis Of Vector Flow Imaging Data In A Pediatric Population, Bailey Stinnett

Biomedical Engineering Undergraduate Honors Theses

Vector flow imaging (VFI) is a new ultrasound technology that provides real time, angle-independent visualization of flow velocities in the heart and great vessels. Thus far, VFI has been used for superficial applications due to the limited penetration depth of available transducer probes; however, this depth in smaller pediatric patients enables adequate aortic views. In this project, VFI was used to study pediatric aortic stenosis (PAS)—a congenital heart defect that results in the narrowing of the aorta and/or aortic valve. The decision to refer PAS patients for surgical or catheter-based intervention is initially based on Doppler ultrasound. VFI is potentially …

Motion Artifact Evaluation Of Coronary Ct Angiography Images, Hongfeng Ma

Dissertations (1934 -)

The objective of this dissertation was to develop and validate an automated algorithm to quantify motion artifact level on coronary CT angiography (CCTA) images. Unlike existing motion artifact reduction techniques that evaluate the relative level of motion artifacts within one exam, this dissertation aims to quantify the absolute level of motion artifacts across exams from varying patients. The ability to quantify absolute motion artifact level enables several potential applications, for example, assessing and comparing two motion artifact reduction techniques. This dissertation includes three specific aims. Aim 1 investigated the absolute motion artifact quantification effectiveness of six motion artifact metrics using …

Evaluating Wall Shear Stress Indices To Uncover Stimuli For Restenosis And Malapposition In Stented Coronary Arteries, Ali A. Aleiou

Master's Theses (2009 -)

The cause of coronary artery neointimal thickening leading to restenosis in ~10% of drug-eluting stents is unknown. Although research suggests adverse values of traditional wall shear stress (WSS) indices may contribute, studies to date have not accounted for stent geometry, which dictates local WSS patterns influencing drug concentration. Recently proposed WSS indices such as WSS variability and WSS exposure time (WSSET) may shed further light on restenosis or, the opposite effect, resorption. The objective of this investigation was to locally evaluate traditional and recently proposed post-stenting metrics and their respective impact on restenosis or resorption. This study used de-identified data …

Validation, Optimization, And Image Processing Of Spiral Cine Dense Magnetic Resonance Imaging For The Quantification Of Left And Right Ventricular Mechanics, Gregory J. Wehner

Theses and Dissertations--Biomedical Engineering

Recent evidence suggests that cardiac mechanics (e.g. cardiac strains) are better measures of heart function compared to common clinical metrics like ejection fraction. However, commonly-used parameters of cardiac mechanics remain limited to just a few measurements averaged over the whole left ventricle. We hypothesized that recent advances in cardiac magnetic resonance imaging (MRI) could be extended to provide measures of cardiac mechanics throughout the left and right ventricles (LV and RV, respectively).

Displacement Encoding with Stimulated Echoes (DENSE) is a cardiac MRI technique that has been validated for measuring LV mechanics at a magnetic field strength of 1.5 T but …

Development And Application Of Gadolinium Free Cardiac Magnetic Resonance Fibrosis Imaging For Multiscale Study Of Heart Failure In Patients With End Stage Renal Disease, Tori A. Stromp

Theses and Dissertations--Physiology

Cardiac magnetic resonance (CMR) is a powerful tool to noninvasively image ventricular fibrosis. Late gadolinium enhancement (LGE) CMR identifies focal and, with T1 mapping, diffuse fibrosis. Despite prevalent cardiac fibrosis and heart failure, patients with end stage renal disease (ESRD) are excluded from LGE. Absence of a suitable diagnostic has limited the understanding of heart failure and obstructed development of therapies in the setting of ESRD. A quantitative, gadolinium free fibrosis detection method could overcome this critical barrier, propelling the advancement of diagnostic, monitoring, and therapy options. This project describes the development of a gadolinium free CMR technique and application …

Icloudecg: A Mobile Cardiac Telemedicine System, David S. Clifford

Masters Theses

With rising healthcare costs and a substantially growing number of patients 65 or over, the benefits of telemedicine and patient self-monitoring systems are becoming increasingly evident. Patients, physicians, hospitals, and even insurance providers benefit from vigilant, cost-effective patient monitoring systems. This thesis describes the development of a portable, smart-phone connected system for continuous cardiac monitoring. The system is capable of continuously monitoring the conditions of the heart, automated detection of cardiac arrhythmias, and real-time notifying patients and physicians of the detected abnormalities. The system consists of four main subsystems: 1) a Bluetooth capable chest-strap ECG, 2) an Android-enabled mobile device, …

Development Of A Heart Rate Variability Measurement System Using Embedded Electronics, Naresh Kumar Velmurugan

Graduate Theses and Dissertations

Recent advances in embedded electronics have a remarkable influence on the health care system. One of the most important applications is to monitor the health care of the patients at anytime and anyplace. In the last two decades, many researchers have focused mainly on heart rate variability (HRV) measurements. Patient's heart rate variability should be continuously monitored to help them in case of emergency. Under these circumstances, patients are required to have a HRV measuring kit for a constant observation.

The proposed project focuses on the development of a heart rate variability measurement system with the use of embedded electronics. …

Augmented Image-Guidance For Transcatheter Aortic Valve Implantation, Pencilla Lang

Electronic Thesis and Dissertation Repository

The introduction of transcatheter aortic valve implantation (TAVI), an innovative stent-based technique for delivery of a bioprosthetic valve, has resulted in a paradigm shift in treatment options for elderly patients with aortic stenosis. While there have been major advancements in valve design and access routes, TAVI still relies largely on single-plane fluoroscopy for intraoperative navigation and guidance, which provides only gross imaging of anatomical structures. Inadequate imaging leading to suboptimal valve positioning contributes to many of the early complications experienced by TAVI patients, including valve embolism, coronary ostia obstruction, paravalvular leak, heart block, and secondary nephrotoxicity from contrast use.

A …

Instrumentation And Control For A Microprocessor-Based Coronary Perfusion System, Daniel L. Priester

Master's Theses (1922-2009) Access restricted to Marquette Campus

No abstract provided.