Biomedical Commons^™

Design Of An Assistive Technology Adaptive Switch Using An Inertial Measurement Unit, Ethan Storm Williams

Graduate Theses and Dissertations

A new assistive technology switch for people with disabilities was developed utilizing an Inertial Measurement Unit (IMU) as the sensor technology. The hardware can be customized through firmware to provide custom switch activations on a person by person basis. The firmware is customized to recognize specific data features in the IMU data which identify the desired switch activation movement performed by the user. In this way, the switch can be adapted to activate based on the movements of the user. During this research, the generic hardware platform, including the IMU sensor technology and Bluetooth communications, was designed and tested. An …

The Connectivity Domain: Analyzing Resting State Fmri Data Using Feature-Based Data-Driven And Model-Based Methods, Armin Iraji, Vince D. Calhoun, Natalie M. Wiseman, Esmaeil Davoodi-Bojd, Mohammad R. N. Avanaki, Zhifeng Kou

Biomedical Engineering Faculty Research Publications

Spontaneous fluctuations of resting state functional MRI (rsfMRI) have been widely used to understand the macro-connectome of the human brain. However, these fluctuations are not synchronized among subjects, which leads to limitations and makes utilization of first-level model-based methods challenging. Considering this limitation of rsfMRI data in the time domain, we propose to transfer the spatiotemporal information of the rsfMRI data to another domain, the connectivity domain, in which each value represents the same effect across subjects. Using a set of seed networks and a connectivity index to calculate the functional connectivity for each seed network, we transform data into …

Deformable Contour Models For Digitizing A Printed Brainstem Atlas, Nirmal J. Patel

Electrical & Computer Engineering Theses & Dissertations

The brainstem is a part of the brain that is connected to the cerebrum and the spinal cord. Ten out of twelve pairs of cranial nerves emerge from the brainstem. The cranial nerves transmit information between the brain and various parts of the body. Due to its anatomical and physiological relevance, a descriptive digital brainstem is important for neurosurgery planning and simulation. For both of these neurosurgical applications, the complexity of the brainstem requires a digital atlas approach to segmentation that maps intensities to tissues rather than less descriptive voxel or surface-based approaches. However, a descriptive brainstem atlas with adequate …

Utilizing Brain-Computer Interfacing To Control Neuroprosthetic Devices, Cheyne J. Angy

Senior Honors Theses

Advances in neuroprosthetics in recent years have made an enormous impact on the quality of life for many people with disabilities, helping them regain the functionality of damaged or impaired abilities. One of the main hurdles to regaining full functionality regarding neuroprosthetics is the integration between the neural prosthetic device and the method in which the neural prosthetic device is controlled or manipulated to function correctly and efficiently. One of the most promising methods for integrating neural prosthetics to an efficient method of control is through Brian-computer Interfacing (BCI). With this method, the neuroprosthetic device is integrated into the human …

Compressive Sensing Framework For Mass Spectrometry Data Analysis, Khalfalla Ahmad Kh. Awedat

Dissertations

Mass Spectrometry (MS) data is ideal for identifying unique bio-signatures of diseases. However, the high dimensionality of MS data hinders any promising MS-based proteomics development. The goal of this dissertation is to develop an accurate classification tool by employing compressive sensing (CS). Not only can CS significantly reduce MS data dimensionality, but it also will allow for full reconstruction of original data. The framework developed in this work is based on using L2 and a mixed L2-L1 norms, allowing an overdetermined system to be resolved. The results show that the L2- based algorithm with regularization terms has a better performance …

Design And Performance Evaluation Of A Prototype Mrf-Based Haptic Interface For Medical Applications, Mehrdad Kermani Ph.D., P.Eng., Nima Najmaei, Ali Asadian, Rajni Patel

Electrical and Computer Engineering Publications

This paper describes the construction and stability and transparency evaluation of a prototype two degrees-of-freedom (DoF) haptic interface, which takes ad-vantage of magneto-rheological fluid (MRF)-based clutches for actuation. These small-scale clutches were designed in our lab, and their evaluation were reported previously [1],[2]. MRF-based actuators exhibit superior characteristics,which can significantly contribute to transparency and stability of haptic devices. Based on these actuators, a distributed antagonistic configuration is used to develop the2-DoF haptic interface. This device is incorporated in a master–slave teleoperation setup intended for medical per-cutaneous interventions and soft-tissue palpation. Preliminary studies on the stability and transparency of the haptic …

Reduced Haemodynamic Coupling And Exercise Are Associated With Vascular Stiffening In Pulmonary Arterial Hypertension, Alessandro Bellofiore, Eric Dinges, Robert Naeije, Hamorabi Mkrdichian, Lauren Beussink-Nelson, Melissa Bailey, Michael Cuttica, Ranya Sweis, James Runo, Jon Keevil, Christopher Francois, Sanjiv Shah, Naomi Chesler

Faculty Publications

Inadequate right ventricular (RV) and pulmonary arterial (PA) functional responses to exercise are important yet poorly understood features of pulmonary arterial hypertension (PAH). This study combined invasive catheterisation with echocardiography to assess RV afterload, RV function and ventricular–vascular coupling in subjects with PAH.

Detecting, Segmenting And Tracking Bio-Medical Objects, Mingzhong Li

Doctoral Dissertations

"Studying the behavior patterns of biomedical objects helps scientists understand the underlying mechanisms. With computer vision techniques, automated monitoring can be implemented for efficient and effective analysis in biomedical studies. Promising applications have been carried out in various research topics, including insect group monitoring, malignant cell detection and segmentation, human organ segmentation and nano-particle tracking.

In general, applications of computer vision techniques in monitoring biomedical objects include the following stages: detection, segmentation and tracking. Challenges in each stage will potentially lead to unsatisfactory results of automated monitoring. These challenges include different foreground-background contrast, fast motion blur, clutter, object overlap and …

Sickle Blood Cell Detection Based On Image Segmentation, Kholoud Alotaibi

Electronic Theses and Dissertations

Red blood cells have a vital role in human health. Red blood cells have a circular shape and a concave surface and exchange the gasses between the inside and outside of the body. However, at times, these normally round cells become sickle shaped, which is an indication of sickle cell disease. This paper introduces a unique approach to detect sickle blood cells in blood samples using image segmentation and shape detection. This method is based on calculating the max axis and min axis of the cell. The form factor is computed using these properties to determine whether the cell is …

Breast Cancer Classification Of Mammographic Masses Using Circularity Max Metric, A New Method, Tae Keun Heo

Electronic Theses and Dissertations

Breast cancer classification can be divided into two categories. The first category is a benign tumor, and the other is a malignant tumor. The main purpose of breast cancer classification is to classify abnormalities into benign or malignant classes and thus help physicians with further analysis by minimizing potential errors that can be made by fatigued or inexperienced physicians. This paper proposes a new shape metric based on the area ratio of a circle to classify mammographic images into benign and malignant class. Support Vector Machine is used as a machine learning tool for training and classification purposes. The improved …

A Dielectric Rod Antenna For Picosecond Pulse Stimulation Of Neurological Tissue, Ross A. Petrella, Karl H. Schoenbach, Shu Xiao

Bioelectrics Publications

A dielectrically loaded wideband rod antenna has been studied as a pulse delivery system to subcutaneous tissues. Simulation results applying 100-ps electrical pulse show that it allows us to generate a critical electric field for biological effects, such as brain stimulation, in the range of several centimeters. In order to reach the critical electric field for biological effects, which is similar to 20 kV/cm, at a depth of 2 cm, the input voltage needs to be 175 kV. The electric field spot size in the brain at this position is similar to 1 cm(2). Experimental studies in free space with …

Comparison Between Electropositive And Electronegative Cold Atmospheric-Pressure Plasmas: A Modelling Study, Ding X. Liu, Jia F. Li, Ai J. Yang, Xiao H. Wang, Ming Z. Rong, Michael G. Kong

Bioelectrics Publications

Cold atmospheric-pressure He + N₂ and He + O₂ plasmas are chosen as the representatives for electropositive and electronegative plasmas, of which the discharge characteristics are studied and then compared to each other by fluid models. As the increase of the impurity (N₂ or O₂) fraction from 0 to 10%, for He + N₂ plasmas the electron density and ion density increase, the spatiotemporal distributions of electron density, ion density, electron temperature and electron generation rate change a little. On contrast, for He + O₂ plasmas the electron density decreases, the ion density …

Implementation Of New System For Oxygen Generation And Carbon Dioxide Removal, Angelo Peter Karavolos

Open Access Theses & Dissertations

This research effort develops an integrated system for CO2 removal and O2 production. A unique material, dodeca-tungsto-phosphoric acid (H3PO4W12O3; henceforth referred to as DTPA) is mixed with tetra-ethyl-ortho-silicate Si(OC2H5)4 or TEOS. This mixture exhibits unique properties of heat absorption and high electrical conductivity. In the system described herein, the DTPA resides within a cross linked arrangement of TEOS. The DTPA furnishes a source of O2, while the TEOS furnishes structural support for the large DTPA crystals. In addition, the large amount of H2O within the crystal also adsorbs CO2. It can also be cross-linked with other polymers such as polycarbonate, …

Electroporation By Subnanosecond Pulses, Iurii Semenov, Shu Xiao, Andrei G. Pakhomov

Bioelectrics Publications

Electropermeabilization of cell membranes by micro- and nanosecond-duration stimuli has been studied extensively, whereas effects of picosecond electric pulses (psEP) remain essentially unexplored. We utilized whole-cell patch clamp and Di-8-ANEPPS voltage-sensitive dye measurements to characterize plasma membrane effects of 500 ps stimuli in rat hippocampal neurons (RHN), NG108, and CHO cells. Even a single 500-ps pulse at 190kV/cm increased membrane conductance and depolarized cells. These effects were augmented by applying brief psEP bursts (5–125 pulses), whereas the rate of pulse delivery (8Hz–1kHz) played little role. psEP-treated cells displayed large inward current at negative membrane potentials but modest or no conductance …

Validation Of An Error Sonification Auditory Feedback Training Program On Proper Sagittal Plane Squat Technique, Rena Hale

Open Access Theses & Dissertations

Osteoarthritis (OA) is one of the most common degenerative joint diseases that hinders an individual's quality of life. A large portion of knee OA instances can be correlated to previous anterior cruciate ligament (ACL) injury. Knee joint injury leading to OA is most prevalent in males aged 20-55 years old and can be caused by improper form during execution of a given task or lack of neuromuscular control. Screening protocols are used to assess deficits of an athlete, with the goal of reducing the risk of injury during both training and in competition. Neuromuscular training programs have been created to …

Detection Of Electrical Alternans In Ventricular Depolarization Phase Of Human Electrocardiogram, David R. Wasemiller

Theses and Dissertations--Biomedical Engineering

T-wave Alternans (TWA) in an electrocardiogram (ECG) has received considerable interest as a potential predictor of sudden cardiac death (SCD). However, large clinical trials have shown that while TWA has a very high negative predictive value, its positive predictive value is poor. Results of previous studies suggest that arrhythmia onset can be affected by the phase relationship of alternans of the depolarization and repolarization phase of the action potentials of the ventricles. To assess this relationship, one would first need to establish that depolarization alternans can be detected and then develop methods to determine its relationship with repolarization alternans, which …

A Software Application For Cardiac-Gated Computerized Tomography Scanning, Stephen Caldwell, Trevor Engelsman

Williams Honors College, Honors Research Projects

Computerized tomography (CT) scans are a common clinical imaging procedure used worldwide. Operating in the X-Ray spectrum, these machines rotate scanners around a stationary body in order to compile two-dimensional images into a unified three-dimensional image. With adjustment to scan frequency and intensity, internal features such as muscles, organs, and tendons can easily be viewed. However, the heart has long evaded CT use due to its near-constant motion. Recently, cardiac-gated scans have entered the market as a technique to image the heart at a specific moment in time when it is nearly still - the quiescent period. Occurring during rapid …

Polyethylene Oxide Nanofiber Production By Electrospinning, H. E. Schneider, J. G. Steuber, W. Du, M. Mortazavi, D. W. Bullock

Journal of the Arkansas Academy of Science

Electrospinning is an inexpensive technique that is used to produce nanofibers for a variety of applications. In electrospinning, a polymer solution is dispensed from a hypodermic-like syringe where an intense electric field attracts the solution to a collector while drawing the polymer into a very thin fiber. The diameter of the fiber can be controlled by tuning the process parameters such as the applied electric field, solution flow rate, distance between syringe tip and collector, and the collector geometry. In this paper we describe results from electrospinning poly(ethylene oxide) (PEO), a likely candidate for applications involving scaffolding for tissue engineering. …

Multifunctional Wearable Epidermal Device For Physiological Signal Monitoring In Sleep Study, J V M S Avinash Kankipati

Masters Theses

"Sleep is the essential part of life. Thousands of people are suffering from different kinds sleep disorders. Clinical diagnosing and treating for such disorders are costly, painful and quite sluggish. To reach the demand many commercial products are into the market to encourage home based sleep studies using portable devices. These portable devices are limited in use, cannot be handled easily and quite costly. Advancements in technology miniaturized these portable devices to wearable devices to make them convenient and economical. Elastic, soft and thin silicon membrane with physical properties well matched with that of the epidermis provides conformal and robust …

Wettability Of Magnesium Based Alloys, Victor Manuel Ornelas

Open Access Theses & Dissertations

The premise of this project was to determine the wettability behavior of Mg-based alloys using three different liquids. Contact angle measurements were carried out along with utilizing the Zisman method for obtaining values for the critical surface tension. Adhesion energy values were also found through the use of the Young-Dupre equation. This project utilized the Mg-based alloy Mg-2Zn-2Gd with supplemented α-Minimum Essential Medium (MEM), Phosphate Buffer Saline solution (PBS), and distilled water. These three liquids are commonly used in cell cultivation and protein adsorption studies. Supplemented α-MEM consisted of α-MEM, fetal bovine serum, and penicillin-streptomycin. Mg-2Zn-2Gd was used because of …