Biomedical Engineering and Bioengineering Commons^™

A Simulation Protocol For Exercise Physiology In Fontan Patients Using A Closed Loop Lumped-Parameter Model, Ethan Kung, Giancarlo Pennati, Francesco Migliavacca, Tian-Yen Hsia, Richard Figliola, Alison Marsden, Alessandro Giardini

Publications

Background: Reduced exercise capacity is nearly universal among Fontan patients, though its etiology is not yet fully understood. While previous computational studies have attempted to model Fontan exercise, they did not fully account for global physiologic mechanisms nor directly compare results against clinical and physiologic data. Methods: In this study, we developed a protocol to simulate Fontan lower-body exercise using a closed-loop lumped-parameter model describing the entire circulation. We analyzed clinical exercise data from a cohort of Fontan patients, incorporated previous clinical findings from literature, quantified a comprehensive list of physiological changes during exercise, translated them into a computational model …

Green Synthesis Of A New Gelatin-Based Antimicrobial Scaffold For Tissue Engineering, Mostafa Yazdimamaghani, Daryoosh Vashaee, Senait Assefa, Mitra Shabrangharehdasht, Armin Tahmasbi Rad, Margaret A. Eastman, Kenneth J. Walker, Sundar V. Madihally, Gerwald A. Köhler, Lobat Tayebi

Chemical and Biochemical Engineering Faculty Research & Creative Works

With the aim of developing appropriate scaffolds for tissue engineering to suppress the formation of biofilms, an effective one-pot process was applied in this study to produce scaffolds with inherent antibacterial activity. A new method to synthesize genipin-crosslinked gelatin/nano silver scaffolds with "green" in situ formation of silver nanoparticles by heat treatment is presented in this paper. In this procedure, toxic solvents, reducing agents, and stabilizing agents are avoided. UV-visible absorption spectra of the synthesized gelatin/nano silver solutions were obtained immediately and three months after the synthesis revealing the presence and high stability of the silver nanoparticles. The TEM of …

Smooth Muscle Cell Organization In The Stem Region Of The Gracilis Collateral Circulation, Amanda Krall

Biomedical Engineering

Many patients who suffer from the ischemic Peripheral Arterial Occlusive Disease (PAOD) experience intermittent claudication, which can be attributed to impaired vasodilation. Collateral vessels are the primary site of resistance to blood flow downstream; therefore maximizing vasodilation in collaterals is crucial for efficient circulation. Collaterals function as natural bypasses around the occluded arteries and the increase in flow into these vessels causes them to outwardly remodel into conduit vessels. However, functional vasodilation in the stem region of collateral vessels is impaired at day 7 following femoral ligation, which can be attributed to smooth muscle cell malfunction. However, the increase in …

2d Wireform Process Improvement, Katy Conlin, Carlo Ebora, Jordan Gamble

Mechanical Engineering

The body of this work has been created for Edwards Lifesciences in conjunction with senior project requirements. As such, the information produced and contained within is under a non‐disclosure agreement. As per request by sponsor, the body of the work will not be submitted to any outside parties, and the title page will serve as proof of completion.

Team Omnimouse, Derek J. Halman, Josh B. Porter, Steven A. Silver, Ian S. Stemper

Computer Engineering

INFORMATION, DATA, FIGURES AND DRAWINGS EMBODIED IN THIS DOCUMENT ARE STRICTLY CONFIDENTIAL AND ARE SUPPLIED ON THE UNDERSTANDING THAT THEY WILL NOT BE DISCLOSED TO THIRD PARTIES WITHOUT THE PRIOR WRITTEN CONSENT OF QUALITY OF LIFE PLUS.

Characterizing The Reproducibility Of The Properties Of Electrospun Poly(D, L-Lactide-Co-Glycolide) Scaffolds For Tissue-Engineered Blood Vessel Mimics, Toni M. Pipes

Master's Theses

“Blood vessel mimics” (BVMs) are tissue-engineered constructs that serve as in vitro preclinical testing models for intravascular devices. The Cal Poly Tissue Engineering lab specifically uses BVMs to test the cellular response to stent implantation. PLGA scaffolds are electrospun in-house using the current “Standard Protocol” and used as the framework for these constructs. The performance of BVMs greatly depends on material and mechanical properties of the scaffolds. It is desirable to create BVMs with reproducible properties so that they can be consistent models that ultimately generate more reliable results for intravascular device testing. Reproducibility stems from the consistency of the …

Development And Implementation Of Assessment Methods For Tissue-Engineered Blood Vessel Mimics, Tanner Stevenson

Biomedical Engineering

Coronary Artery Disease (CAD), the most prevalent form of heart disease, is the result of clogged or damaged coronary arteries and claims around 380,000 Americans annually. A common treatment for CAD involves placing a stent into the artery in order to open the lumen and support the native tissue—a procedure that drastically reduces patient recovery times in comparison to heart bypass surgery. However, stents do not always interact well with the body and require additions such as surface coatings or drug elution in order for additional biocompatibility. These additions necessitate extensive in vitro and in vivo testing which are expensive …

Functional Vasodilation Is Impaired In Arterialized Capillaries In The Spinotrapezius, Joshua P. Cutts

Biomedical Engineering

Ischemic diseases are the result of atherosclerotic plaques, which occlude conduit arteries. Ischemic disease in different tissues leads to different conditions, such as coronary artery disease (CHD), cerebrovascular disease (CVD), and peripheral arterial occlusive disease (PAOD). Patient vasculature architecture is variable; some patients having many collateral vessels, which are connect one arterial branch to another, and readily serve as natural bypass routes to atherosclerotic occlusions, to enlarge and provide blood flow to tissue distal to the occlusion. Patients with many natural collateral vessels are ischemia protected. Unfortunately, not all patients have collateral arterioles to remodel into conduit vessels and provide …

Sonar For The Visually Impaired, Anastasia Newark, Edwin Ng, Scott Terhorst

Biomedical Engineering

There are currently no inexpensive assistive devices that allow the visually impaired detect low hanging objects that are above waist height and may cause injury, such as a rope or tree branch. The challenge presented to the team by the Quality of Life Plus Lab (QL+) was to develop a Sonar Cane device that attaches to a traditional white cane to address this problem. This device must be lightweight, inexpensive to manufacture, have a long battery life, and accurately detect obstacles to prevent user injury.

Learning Redundant Motor Tasks With And Without Overlapping Dimensions: Facilitation And Interference Effects, Rajiv Ranganathan, Jon A. Wieser, Kristine M. Mosier, Ferdinando A. Mussa-Ivaldi, Robert A. Scheidt

Biomedical Engineering Faculty Research and Publications

Prior learning of a motor skill creates motor memories that can facilitate or interfere with learning of new, but related, motor skills. One hypothesis of motor learning posits that for a sensorimotor task with redundant degrees of freedom, the nervous system learns the geometric structure of the task and improves performance by selectively operating within that task space. We tested this hypothesis by examining if transfer of learning between two tasks depends on shared dimensionality between their respective task spaces. Human participants wore a data glove and learned to manipulate a computer cursor by moving their fingers. Separate groups of …

Developing Defined And Scalable 3d Culture Systems For Culturing Human Pluripotent Stem Cells At High Densities, Yuguo Lei, Daeun Jeong, Jifang Xiao, David V. Schaffer

Department of Chemical and Biomolecular Engineering: Faculty Publications

Human pluripotent stem cells (hPSCs)—including embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs)—are very promising candidates for cell therapies, tissue engineering, high throughput pharmacology screens, and toxicity testing. These applications require large numbers of high quality cells; however, scalable production of human pluripotent stem cells and their derivatives at a high density and under well-defined conditions has been a challenge. We recently reported a simple, efficient, fully defined, scalable, and good manufacturing practice (GMP) compatible 3D culture system based on a thermoreversible hydrogel for hPSC expansion and differentiation. Here, we describe additional design rationale and characterization of this …

Clear Circuit Contact Lens, Paul Hecker Ii, Phillip Azar, Alexander Do, Benny Ng, Errol Leon

Electrical Engineering

The clear active contact lens project aims to address safety and hazard awareness with an unexplored field of eye wear technology. With advancements in nanotechnology and the advent of circuits on contact lens, this project is one of the first research and development into this new field, following University of Washington and Google. The team focuses on the safety and biocompatibility of the contact lens for a comfortable ease of use. The designs push the limits of thin film printed technology with its pursuit of fine designs of 250μm antennas. The project streamlines the manufacturing process for a combination substrate …

The Effect Of Fiber Depth On The Estimation Of Peripheral Nerve Fiber Diameter Using Group Delay And Simulated Annealing Optimization, Nam Tran

Master's Theses

Peripheral neuropathy refers to diseases of or injuries to the peripheral nerves in the human body. The damage can interfere with the vital connection between the central nervous system and other parts of the body, and can significantly reduce the quality of life of those affected. In the US, approximately between 15 and 20 million people over the age of 40 have some forms of peripheral neuropathy. The diagnosis of peripheral neuropathy often requires an invasive operation such as a biopsy because different forms of peripheral neuropathy can affect different types of nerve fibers. There are non-invasive methods available to …

The Effect Of Neurostimulation On Blood Flow And Ischemic Pain, Stacey M. Fishman

Biomedical Engineering

Chronic pain caused by lack of blood flow is known as ischemic pain. Neurostimulation, the application of electrical currents through a region of the body, is effective for pain modulation, and it is hypothesized that this can be explained by the gate control theory and alterations of the sympathetic output initiated by the metaboreflex. The decrease of sympathetic output reduces vasoconstriction and improves blood flow. Transcutaneous electrical nerve stimulation (TENS) and interferential currents (IFC) stimulation, both non-invasive neurostimulation techniques, were evaluated for their effects on cutaneous blood flow on the palm. High or low frequency TENS and/or IFC, and the …

Alternate Computer Input Device For Individuals With Quadriplegia, Tobais Elder, Michelle Martinez, David Sylvester

Biomedical Engineering

This project details the design development of an alternative computer input system that allows a person with quadriplegia to move a computer's cursor and activate left and right click button inputs. After researching and analyzing possible solutions, an end design was chosen that most appropriately satisfied all user requirements and engineering specifications. This final design employs a head mounted Inertial Measurement Unit (IMU) with 9 DoF (Degrees of Freedom) to track head movements and correlate these motions to computer cursor movements. A Sip-Puff Transducer monitors and interprets a user's application of negative and positive air pressure differentials to a vinyl …

Electroencephalogram Coherence In Children With And Without Autism Spectrum Disorders: Decreased Interhemispheric Connectivity In Autism, Audrey Meyer Carson, Nicole M.G. Salowitz, Robert A. Scheidt, Bridget K. Dolan, Amy V. Van Hecke

Biomedical Engineering Faculty Research and Publications

Electroencephalogram coherence was measured in children with autism spectrum disorders (ASD) and control children at baseline and while watching videos of a familiar and unfamiliar person reading a story. Coherence was measured between the left and right hemispheres of the frontal, parietal, and temporal-parietal lobes (interhemispheric) and between the frontal and parietal lobes in each hemisphere (intrahemispheric). A data-reduction technique was employed to identify the frequency (alpha) that yielded significant differences in video conditions. Children with ASD displayed reduced coherence at the alpha frequency between the left and right temporal-parietal lobes in all conditions and reduced coherence at the alpha …

Neuromodulation: Action Potential Modeling, Vladimir Ruzov

Master's Theses

There have been many different studies performed in order to examine various properties of neurons. One of the most important properties of neurons is an ability to originate and propagate action potential. The action potential is a source of communication between different neural structures located in different anatomical regions. Many different studies use modeling to describe the action potential and its properties. These models mathematically describe physical properties of neurons and analyze and explain biological and electrochemical processes such as action potential initiation and propagation. Therefore, one of the most important functions of neurons is an ability to provide communication …

Design And Validation Of A Wearable, Continuous, And Non-Invasive Hydration Monitor That Uses Ultrasonic Pulses To Detect Changes In Tissue Hydration Status, Zoie Engman

Master's Theses

Chronic dehydration is an endemic problem for many population groups. Current methods of monitoring hydration status are invasive, time consuming, cannot be performed while exercising, and require lab resources. A proposed solution is a wearable, continuous, and non-invasive device that uses harm-free ultrasonic pulses to detect changes in tissue hydration status over time. Customer and engineering requirements were defined and used to guide the design process. Literature reviews were performed to identify essential information on dehydration, assess current methods, discover state of the art devices, and describe ultrasonic theory. Market research was performed to identify athletes as the target population …

In Vivo Imaging Of Human Cone Photoreceptor Inner Segments, Drew Scoles, Yusufu N. Sulai, Christopher S. Langlo, Gerald A. Fishman, Christine A. Curcio, Joseph Carroll, Alfredo Dubra

Biomedical Engineering Faculty Research and Publications

Purpose.

An often overlooked prerequisite to cone photoreceptor gene therapy development is residual photoreceptor structure that can be rescued. While advances in adaptive optics (AO) retinal imaging have recently enabled direct visualization of individual cone and rod photoreceptors in the living human retina, these techniques largely detect strongly directionally-backscattered (waveguided) light from normal intact photoreceptors. This represents a major limitation in using existing AO imaging to quantify structure of remnant cones in degenerating retina.

Methods.

Photoreceptor inner segment structure was assessed with a novel AO scanning light ophthalmoscopy (AOSLO) differential phase technique, that we termed nonconfocal split-detector, in two healthy …

Characterizing Motor Control Signals In The Spinal Cord, Yi Guo

Dissertations

The main goal of this project is to develop a rodent model to study the central command signals generated in the brain and spinal cord for the control of motor function in the forearms. The nature of the central command signal has been debated for many decades with only limited progress. This thesis presents a project that investigated this problem using novel techniques. Rats are instrumented to record the control signals in their spinal cord while they are performing lever press task they are trained in. A haptic interface and wireless neural data amplifier system simultaneously collects dynamic and neural …