Engineering Commons^™

An Acoustic Fluid-Structure Simulation Of A Theraputic Ultrasound Wire Waveguide Apparatus, Graham Gavin, M.S. Hashmi, Finbar Dolan, Garrett Mcguinness

Conference Papers

The use of high-power low-frequency ultrasound transmitted down small diameter wire waveguides is an emerging technology that may have potential in the treatment of complicated atherosclerotic plaques in cardiovascular surgery. This form of energy delivery results in vibrating the distal-tip of the wire waveguide disrupting material by means of direct contact ablation and also cavitation, pressure waves and acoustic streaming in the surrounding fluid. This work describes a numerical acoustic fluid-structure model of the ultrasound wire waveguide and blood surrounding the distal tip. The structural analysis of the model predicts the natural frequencies of the waveguide and shows the extent …

Development And Performance Characteristics Of An Ultrasound Angioplasty Device, Graham Gavin, Garrett Mcguinness, Finbar Dolan, M.S. J. Hashmi

Conference Papers

INTRODUCTION The effect of atherosclerosis is well documented and many procedures such as balloon angioplasty and stentimplantation have been developed to reopen occluded arteries. However, there are considerable differences in the material properties of various atherosclerotic lesions as they develop. Many authors have suggested that rigid calcified plaques may require specific procedures that target this rigid material through de-bulking or complete removal (Salunke et al, 1997). Ultrasound angioplasty is the delivery of high power low frequency ultrasound via a wire waveguide to the lesion location. This results in distal tip wire displacements of up to 100um peak-to-peak (p-p) at frequencies …

A Real-Time Haptic/Graphic Demonstration Of How Error Augmentation Can Enhance Learning, Yejun Wei, James L. Patton, Preeti Bajaj, Robert A. Scheidt

Biomedical Engineering Faculty Research and Publications

We developed a real-time controller for a 2 degree-of-freedom robotic system using xPC Target. This system was used to investigate how different methods of performance error feedback can lead to faster and more complete motor learning in individuals asked to compensate for a novel visuo-motor transformation (a 30 degree rotation). Four groups of human subjects were asked to reach with their unseen arm to visual targets surrounding a central starting location. A cursor tracking hand motion was provided during each reach. For one group of subjects, deviations from the “ideal” compensatory hand movement (i.e. trajectory errors) were amplified with a …

Visual Error Augmentation For Enhancing Motor Learning And Rehabilitative Relearning, Yejun Wei, Preeti Bajaj, Robert A. Scheidt, James L. Patton

Biomedical Engineering Faculty Research and Publications

We developed a real-time controller for a 2 degree-of-freedom robotic system using xPC Target. This system was used to investigate how different methods of performance error feedback can lead to faster and more complete motor learning in individuals asked to compensate for a novel visuo-motor transformation (a 30 degree rotation). Four groups of normal human subjects were asked to reach with their unseen arm to visual targets surrounding a central starting location. A cursor tracking hand motion was provided during each reach. For one group of subjects, deviations from the "ideal" compensatory hand movement (i.e. trajectory errors) were amplified with …

Characterization Of Motor Adaptation And Limb Posture Regulation During Arm Reaching Movements Following Stroke, Robert A. Scheidt, Tina M. Stoeckmann

Biomedical Engineering Faculty Research and Publications

Whether attempting to pour water into a handheld glass, or simply trying to hold a young child's hand, many activities of daily living require interaction with unpredictable or uncertain mechanical environments. Here we describe a systems identification study that used a planar manipulandum to characterize how hemiparetic stroke survivors adapt reaching movements to novel mechanical environments. By analyzing trial-by-trial variations in hand path kinematics, we found that stroke survivors are less likely than neurologically-intact subjects to adjust motor commands for upcoming movements based on hand trajectory errors experienced on previous trials. This ability is most significantly compromised in subjects with …

A Dynamic Neuro-Fuzzy Model Providing Bio-State Estimation And Prognosis Prediction For Wearable Intelligent Assistants, Yu Wang, Jack M. Winters

Biomedical Engineering Faculty Research and Publications

Background

Intelligent management of wearable applications in rehabilitation requires an understanding of the current context, which is constantly changing over the rehabilitation process because of changes in the person's status and environment. This paper presents a dynamic recurrent neuro-fuzzy system that implements expert-and evidence-based reasoning. It is intended to provide context-awareness for wearable intelligent agents/assistants (WIAs).

Methods

The model structure includes the following types of signals: inputs, states, outputs and outcomes. Inputs are facts or events which have effects on patients' physiological and rehabilitative states; different classes of inputs (e.g., facts, context, medication, therapy) have different nonlinear mappings to a …

A Physiologically Based Clinical Measure For Spastic Reflexes In Spinal Cord Injury, Ela N. Benz, T. George Hornby, Rita K. Bode, Robert A. Scheidt, Brian D. Schmit

Biomedical Engineering Faculty Research and Publications

Objective: To test the validity of the Spinal Cord Assessment Tool for Spastic reflexes (SCATS), a clinical tool intended to rate spastic motor behavior after spinal cord injury (SCI).

Design: By using correlational analyses, the SCATS was validated using concurrent measurements of kinematics and electromyograms and traditional assessments of spasms and spastic hypertonia.

Setting: Research laboratory (kinematics and electromyography) and outpatient medical clinic (traditional measures of spastic hypertonia).

Participants: Eleven people with SCI were used for kinematic and electromyographic measurements. Seventeen people with SCI were used for comparison with other clinical scales.

Interventions: Not applicable. …

Fast Measurements Of Flow Through Mitral Regurgitant Orifices With Magnetic Resonance Phase Velocity Mapping, Haosen Zhang, Sandra S. Halliburton, Richard D. White, George P. Chatzimavroudis

Chemical & Biomedical Engineering Faculty Publications

Magnetic-resonance (MR) phase velocity mapping (PVM) shows promise in measuring the mitral regurgitant volume. However, in its conventional nonsegmented form, MR-PVM is slow and impractical for clinical use. The aim of this study was to evaluate the accuracy of rapid, segmented k-spaceMR-PVM in quantifying the mitral regurgitant flow through a control volume (CV) method. Two segmented MR-PVM schemes, one with seven (seg-7) and one with nine (seg-9) lines per segment, were evaluated in acrylic regurgitant mitral valve models under steady and pulsatile flow. A nonsegmented (nonseg) MR-PVM acquisition was also performed for reference. The segmented acquisitions were …

Quantitative Models Of The Rat Pulmonary Arterial Tree Morphometry Applied To Hypoxia-Induced Arterial Remodeling, Robert C. Molthen, Kelly L. Karau, Christopher A. Dawson

Biomedical Engineering Faculty Research and Publications

Little is known about the constituent hemodynamic consequences of structural changes that occur in the pulmonary arteries during the onset and progression of pulmonary arterial remodeling. Many disease processes are known to be responsible for vascular remodeling that leads to pulmonary arterial hypertension, cor pulmonale, and death. Histology has been the primary tool for evaluating pulmonary remodeling, but it does not provide information on intact vascular structure or the vessel mechanical properties. This study is an extension of our previous work in which we developed an alternative imaging technique to evaluate pulmonary arterial structure. The lungs from Sprague-Dawley rats were …

The Impossible Dose - How Can Something Simple Be So Complex? , Lars Hode

Light Activated Tissue Regeneration and Therapy

No abstract provided.

Genetic Engineering Of Syringyl-Enriched Lignin In Plants, Vincent Lee C. Chiang, Laigeng Li

Michigan Tech Patents

The present invention relates to a novel DNA sequence, which encodes a previously unidentified lignin biosynthetic pathway enzyme, sinapyl alcohol dehydrogenase (SAD) that regulates the biosynthesis of syringyl lignin in plants. Also provided are methods for incorporating this novel SAD gene sequence or substantially similar sequences into a plant genome for genetic engineering of syringyl-enriched lignin in plants.

Biomimetic Synthesis Within Polyelectrolyte Microcapsules: Characterization Of Enzyme Catalyzed Polyphenols And Polypeptides, Rohit C. Ghan

Doctoral Dissertations

An enzyme-catalyzed synthesis of novel polymers within layer-by-layer (LbL) constructed polyelectrolyte microcapsules has been developed. This approach is based on the selective permeability of polyelectrolyte-capsule walls to monomer molecules. Conversely biocatalysts and forming polymeric chains cannot exit the micro-capsule interior because of their characteristic high molecular weight. Horseradish Peroxidase (HRP) was encapsulated into four bilayer PSS (poly-styrenesulfonate)/PAH (poly-allylamine hydrochloride) capsules with an average diameter of 5 μm using pH-driven pore opening. The polymerization of 4-(2-Aminoethyl) phenol hydrochloride (tyramine) catalyzed by HRP produces easily detectable fluorescent polymeric products after the addition of hydrogen peroxide to the system. It is known that …

Distal Placement Of An End-To-Side Bypass Graft Anastomosis A 3-D Computational Study, John Robert Di Cicco

Mechanical & Aerospace Engineering Theses & Dissertations

A three-dimensional computational fluid dynamics study of blood flow through stenotic arteries has been conducted. Flow phenomena, such as separation regions and turbulence, can be found distal to an arterial stenosis. Frequently, a bypass graft using an end-to-side technique is attached to a stenotic artery to restore adequate blood flow. However, a significant percentage of these grafts fail after thirty postoperative days due to intimal hyperplasia development around the distal anastomosis. Moreover, aberrant wall shear rates have been implicated as a factor in the development of intimal hyperplasia. Thus, the present study examines whether placement of the distal end of …

Do Microcracks Decrease Or Increase Fatigue Resistance In Cortical Bone?, O. S. Sobelman, J. C. Gibeling, S. M. Stover, S. J. Hazelwood, O. C. Yeh, D. R. Shelton, R. B. Martin

Biomedical Engineering

Fatigue of cortical bone produces microcracks; it has been hypothesized that these cracks are analogous to those occurring in engineered composite materials and constitute a similar mechanism for fatigue resistance. However, the numbers of these linear microcracks increase substantially with age, suggesting that they contribute to increased fracture incidence among the elderly. To test these opposing hypotheses, we fatigued 20 beams of femoral cortical bone from elderly men and women in load-controlled four point bending having initial strain ranges of 3000 or 5000 microstrain. Loading was stopped at fracture or 106 cycles, whichever occurred first, and microcrack density and length …

Varying The Time Delay Of An Action Potential Elicited With A Neural-Electronic Stimulator, Robert B. Szlavik, Frank Jenkins

Biomedical Engineering

There have been various theoretical and experimental studies presented in the literature that focus on interfacing neurons with discrete electronic devices such as transistors. It has also been demonstrated experimentally that neural-electronic devices can be used to elicit action potentials in a target neuron in close proximity to the neural-electronic stimulator. The time delay between stimulus and the onset of the neural action potential can be varied by varying the pulse amplitude and width generated by the neural-electronic stimulator (transistor).

Determining Suitability Of A Fly Ash For Silica Extraction And Zeolite Synthesis, Natàlia Moreno, Xavier Querol, Angel López-Soler, José Manuel Andres, Maria Janssen, Henk Nugteren, Mark R. Towler, Kenneth Stanton

Chemical and Biochemical Engineering Faculty Research & Creative Works

Zeolitic material is obtained from fly ash both by direct conversion of the ash or from SiO₂ extracts obtained from fly ash. This study focuses on determining the suitability of a fly ash for SiO₂ extraction and for zeolite synthesis by direct conversion. The SiO₂ extraction experiments from different fly ashes show that the main parameters governing the SiO₂ extraction are: (a) a high bulk SiO₂ content (> 52%, for obtaining an extraction yield of 100 g SiO₂ kg-1) in the starting fly ash, (b) a high proportion (> 55%) of the bulk SiO …

Thermal Analysis Of Poly(Desamino Arylates), Ali Cem Recber

Theses

The goal of this study is to better understand the thermal characteristics and molecular behavior of two poly(desaminotyrosyl arylates). These two polymers were chosen from a combinatorial library of polymers developed by changing the type and size of the two substitutable chain locations. TGA, DSC and TSC studies were conducted on Poly(12,10) and Poly(2,2) after the samples were exposed to various conditions. The TGA of Poly(12,10) shows low water uptake at 25° C, higher water uptake at 80°C. Water uptake for Poly(2,2) at 25°C is similar to Poly(12,10) at 80°C. The Thermally Stimulated Current analysis (TSC) results indicate a molecular …

Characterization Of Mechanical Behavior Of Electrospun Non-Woven Mats, Ajitha Patlolla

Theses

Electrospinning is a simple and efficient method for the production of nanometer to micrometer fibers. While the process of electrospinning has been known for over half a century, current understanding of the process and those parameters that affect the properties of the fibers is very limited. Not much work has been done in the field electrospinning process to study the mechanical properties of nonwoven mats produced and to study parameters affecting their properties.

In the first part of this thesis electrospun nonwoven mats made of poly(lactides) solutions were characterized based on their mechanical behavior in biorelevant conditions. In the second …

Effect Of 655 Nm Diode Laser On Dog Sperm Motility , M. I. Corral-Baqués, T. Rigau, M. Ribera, J. E. Rodríguez, J. Rigau

Light Activated Tissue Regeneration and Therapy

No abstract provided.

New Steps Towards An Understanding Of The Mechanisms Behind Photobiomodulation, Lars Hode

Light Activated Tissue Regeneration and Therapy

No abstract provided.

Laser – A Therapeutic Intervention For Controlling Lymphoedema, Lynette E. Barnet

Light Activated Tissue Regeneration and Therapy

No abstract provided.

Treating Lymphoedema With Low Level Laser Therapy, Sandy Anderson, Neil Piller, Colin Carati, Bren Gannon, Ann Angel

Light Activated Tissue Regeneration and Therapy

No abstract provided.

Low Level Laser Reduces The Severity Of Radiotherapy Induced Oral Mucositis And Xerostomia, Carlos De Oliveira Lopes, Josepa Rigau, Ana Ortega Lopez, Renato A. Zangaro

Light Activated Tissue Regeneration and Therapy

No abstract provided.

Leli For Acute Stroke, Jackson Streeter

Light Activated Tissue Regeneration and Therapy

No abstract provided.

Effect Of Low Power 655 And 830 Nm Diode Laser Irradiation On The Neuromuscular Junctions Of Mouse Diaphragm, Renata A. Nicolau, Manel Santafé, Josepa Rigau, Josep M. Tomàs

Light Activated Tissue Regeneration and Therapy

No abstract provided.

Techniques For Investigation Of Surgical Cutting Instruments, Eamon Price, Ger Reilly, Brendan Mccormack, Andrew Macey

Conference Papers

No abstract provided.

Strategies For Improving Peripheral Nerve Regeneration After Severe Lesions: The Potential Role Of Low-Level Laser Therapy, Stefano Geuna

Light Activated Tissue Regeneration and Therapy

No abstract provided.

Neuronal Response To Injury, Rosemary C. Borke, Juanita J. Anders

Light Activated Tissue Regeneration and Therapy

No abstract provided.

810 Nm Light Therapy Improves Axonal Regeneration And Functional Recovery Following Acute Spinal Cord Injury , K. R. Byrnes, X. Wu, R. W. Waynant, I. K. Ilev, K. Smith, L. Barna, J. J. Anders

Light Activated Tissue Regeneration and Therapy

No abstract provided.

Metronomic Photodynamic Therapy: Principle To Practice, Stuart K. Bisland

Light Activated Tissue Regeneration and Therapy

No abstract provided.