Biomedical Engineering and Bioengineering Commons^™

Technology-Assisted Stroke Rehabilitation In Mexico: A Pilot Randomized Trial Comparing Traditional Therapy To Circuit Training In A Robot/Technology-Assisted Therapy Gym, Karla Bustamante Valles, Sandra Montes, Maria De Jesus Madrigal, Adan Burciaga, María Elena Martínez, Michelle J. Johnson

Biomedical Engineering Faculty Research and Publications

Background

Stroke rehabilitation in low- and middle-income countries, such as Mexico, is often hampered by lack of clinical resources and funding. To provide a cost-effective solution for comprehensive post-stroke rehabilitation that can alleviate the need for one-on-one physical or occupational therapy, in lower and upper extremities, we proposed and implemented a technology-assisted rehabilitation gymnasium in Chihuahua, Mexico. The Gymnasium for Robotic Rehabilitation (Robot Gym) consisted of low- and high-tech systems for upper and lower limb rehabilitation. Our hypothesis is that the Robot Gym can provide a cost- and labor-efficient alternative for post-stroke rehabilitation, while being more or as effective as …

Microfluidic Devices In Biotechnology, Maribel Vazquez

Open Educational Resources

This lecture/laboratory course focuses on the fundamentals of modern microfluidic devices with applications to biomedical measurements. Students will review fundamental properties of microfluidic systems including the effects of viscous flow, heat transfer, and electromagnetic phenomena on biological systems. Multiple laboratory modules will expose students to photolithographic and surface treatment techniques required for device development. An end of term project will require students to analyze designs of upcoming biomedical inventions and present their critiques via written report and oral presentation.

Polymeric Prodrug, David A. Puleo, Thomas D. Dziubla, Theodora Asafo-Adjei

Biomedical Engineering Faculty Patents

The presently-disclosed subject matter includes compounds that comprise an initiator and an active agent that is covalently bonded to the initiator through a ring-opening polymerization process, an atom-transfer radical polymerization process, a Michael addition reaction, or a ring-opening metathesis polymerization process. In some embodiments the active agent includes simvastatin. The presently-disclosed subject matter also includes methods for making the compositions and methods for using the compositions to treat tissue wounds.

An Interactive Videogame Designed To Improve Respiratory Navigator Efficiency In Children Undergoing Cardiovascular Magnetic Resonance, Sean M. Hamlet, Christopher M. Haggerty, Jonathan D. Suever, Gregory J. Wehner, Jonathan D. Grabau, Kristin N. Andres, Moriel H. Vandsburger, David K. Powell, Vincent L. Sorrell, Brandon K. Fornwalt

Saha Cardiovascular Research Center Faculty Publications

Background: Advanced cardiovascular magnetic resonance (CMR) acquisitions often require long scan durations that necessitate respiratory navigator gating. The tradeoff of navigator gating is reduced scan efficiency, particularly when the patient’s breathing patterns are inconsistent, as is commonly seen in children. We hypothesized that engaging pediatric participants with a navigator-controlled videogame to help control breathing patterns would improve navigator efficiency and maintain image quality.

Methods: We developed custom software that processed the Siemens respiratory navigator image in real-time during CMR and represented diaphragm position using a cartoon avatar, which was projected to the participant in the scanner as visual feedback. The …

Imaging Right Ventricular Function To Predict Outcome In Pulmonary Arterial Hypertension, Alessandro Bellofiore, Melanie Brewis, Rebecca Vanderpool, Naomi Chesler, Martin Johnson, Robert Naeije, Andrew Peacock

Faculty Publications

Right ventricular (RV) function is a major determinant of outcome in pulmonary arterial hypertension (PAH). However, uncertainty persists about the optimal method of evaluation.MethodsWe measured RV end-systolic and end-diastolic volumes (ESV and EDV) using cardiac magnetic resonance imaging and RV pressures during right heart catheterization in 140 incident PAH patients and 22 controls. A maximum RV pressure (Pmax) was calculated from the nonlinear extrapolations of early and late systolic portions of the RV pressure curve. The gold standard measure of RV function adaptation to afterload, or RV–arterial coupling (Ees/Ea) was estimated by the stroke volume (SV)/ESV ratio (volume method) or …

Rapid Generation Of 3d Microchannels Using A Multiphoton Laser System In Blended Hydrogels To Serve As Templates For Microvascular Generation, Stephanie Renée Burtch

Theses and Dissertations

Lack of scaffold microvascularization is one of the biggest problems facing graft survival and success within current tissue engineering applications. Fortunately, techniques aiming to form microchannels within three-dimensional scaffolds have shown promise in providing templates for tube-like cell formations. Unfortunately, many current patterning approaches are limited in the types of materials the technique can be applied to and lack the ability to form capillary-sized (<10 microns in diameter) networks. In this study, a multiphoton laser was used to create channels down to the micron level within an optically-clear hydrogel scaffold. Different percentages of poly (ethylene glycol) diacryate (PEGDA) and collagen were used to create different blends of hydrogels at 0%, 1%, 2%, and 3% collagen/PEGDA (w/w). Mechanical and transmittance testing were performed on all blends in order to determine which had optimal mechanical strength and optical clarity for laser subtractive printing. Swelling and degradation were measured to confirm the scaffolds served the tissue engineering requirement of eventual degradation. All gels with PEGDA incorporation showed an increase in mechanical stability and transparency when compared to pure collagen gels. Hydrogel blends showed resistance to degradation in phosphate-buffered saline, but appeared to exhibit collagen degradation in collagenase, although no statistical significance was seen. Cell viability tests within the hydrogels showed viability in cell-seeded hydrogels when compared to dead controls, although cells lacked some markers of healthy cells, such as spreading. In conclusion, results show that hydrogel blends provide a good matrix for subtractive optical micropatterning approaches, although other types of hydrogels may improve cell spreading and other cell responses.

Materials And Techniques Used In Cranioplasty Fixation: A Review, Basel A. Khader, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Cranioplasty is the surgical repair of a deficiency or deformity of the skull. The purpose of cranioplasty is to provide protection for the brain following cranial surgery, and to offer relief to psychological disadvantages while increasing social performance. There are several materials that had been used for cranioplasty, but an ideal product has yet to be developed, hence the ongoing research into biologic and non-biologic alternatives to the existing materials. This article critiques the products currently used for cranioplasty in order to facilitate the development of new materials, which can improve patient outcomes.

Selecting Medical Hardware Using Pairwise Comparisons: A Patient's Perspective Of Cochlear Implant Device Selection, Timothy R. Anderson, Shabnam Razeghian Jahromi

Engineering and Technology Management Faculty Publications and Presentations

Selecting medical hardware can be a difficult and permanent decision for patients that they are often unprepared for. The authors explore the use of pairwise comparison techniques to better inform medical decision making in an application of choosing between three major cochlear implant manufacturers. This paper appears to be the first study to apply a pairwise comparison decision making approach for cochlear implant device selection. Also, unlike many medical decision making studies that are developed by the healthcare professional, this model and analysis was conducted entirely by the patient for the purpose of making the real-world decision of a device. …

Brain Encoding Of Saltatory Velocity-Scaled Somatosensory Array In Glabrous Hand Among Neurotypical Adults, Hyuntaek Oh

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Neurons in human somatosensory cortex are somatotopically organized, with sensation from the lower limbs mediated by neurons near the midline of the brain, whereas sensations from the upper body, hands and orofacial surfaces are mediated by neurons located more laterally in a sequential map. Neurons in Brodmann's area (BA) 3b are exquisitely sensitive to tactile stimulation of these skin surfaces. Moreover, the location, velocity and direction of tactile stimuli on the skin's surface are discriminable features of somatosensory processing, however their role in fine motor control and passive detection are poorly understood in health, and as a neurotherapeutic agent in …

Microdose Fluorescence Imaging Of Aby-029 On An Operating Microscope Adapted By Custom Illumination And Imaging Modules, Jonathan T. Elliott, Alisha V. Dsouza, Kayla Marra, Brian W. Pogue, David Roberts, Keith Paulsen

Dartmouth Scholarship

Fluorescence guided surgery has the potential to positively impact surgical oncology; current operating microscopes and stand-alone imaging systems are too insensitive or too cumbersome to maximally take advantage of new tumor-specific agents developed through the microdose pathway. To this end, a custom-built illumination and imaging module enabling picomolar-sensitive near-infrared fluorescence imaging on a commercial operating microscope is described. The limits of detection and system specifications are characterized, and in vivo efficacy of the system in detecting ABY-029 is evaluated in a rat orthotopic glioma model following microdose injections, showing the suitability of the device for microdose phase 0 clinical trials.

Methanol And Dimethyl Ether From Renewable Hydrogen And Carbon Dioxide: Alternative Fuels Production And Life-Cycle Assessment, Michael J. Matzen, Yaşar Demirel

Yaşar Demirel Publications

In this work we investigate two renewably based alternative fuels; methanol and dimethyl ether. The ultimate feedstocks for production are wind-based electrolytic hydrogen and carbon dioxide captured from an ethanol fermentation process. Dimethyl ether production was modeled in ASPEN Plus using a previously simulated methanol production facility. The facilities use 18.6 metric tons (mt) of H₂ and 138.4 mt CO₂ per day. Methanol is produced at a rate 96.7 mt/day (99.5 wt%) and dimethyl ether is produced at a rate of 68.5 mt/day (99.6 wt%). A full comparative life-cycle assessment (cradle-to-grave) of both fuels was conducted to investigate …

Monitoring Of Tissue Optical Properties During Thermal Coagulation Of Ex Vivo Tissues, Vivek K. Nagarajan, Bing Yu

Biomedical Engineering Faculty Research and Publications

Background and Objective

Real-time monitoring of tissue status during thermal ablation of tumors is critical to ensure complete destruction of tumor mass, while avoiding tissue charring and excessive damage to normal tissues. Currently, magnetic resonance thermometry (MRT), along with magnetic resonance imaging (MRI), is the most commonly used technique for monitoring and assessing thermal ablation process in soft tissues. MRT/MRI is very expensive, bulky, and often subject to motion artifacts. On the other hand, light propagation within tissue is sensitive to changes in tissue microstructure and physiology which could be used to directly quantify the extent of tissue damage. Furthermore, …

Segmental Kinematic Analysis Of Planovalgus Feet In Children With Cerebral Palsy, K. Kruger, K. Konop, Joseph Krzak, Adam Graf, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Application Of Bioinstrumentation In Developing A Pressure Suit For Suborbital Flight, Pedro Llanos, Erik Seedhouse

Publications

This presentation features Embry-Riddle Aeronautical University's U-2 pressure suit. Built to be light and cost-effective, this suit is comfortable, comes in multiple sizes, operates in pressures up to 5 PSID, has an active airflow-based cooling system, and features bio-instrumentation to measure heart rate, breathing rate, skin temperature and other vitals.

A 3-D Multiplex Paper-Microfluidic Platform, Mitchell Patrick Young

Master's Theses

3-D paper-based microfluidic devices (micoPADs) are small and portable devices made out of paper that offer a promising platform for diagnostic applications outside of a laboratory. These devices are easy to use, low cost, require no power source, and capable of detecting multiple targets simultaneously. The work in this thesis demonstrated the ability of a 3-D paper-microfluidic platform to simultaneously detect 5 targets. Rubber cord stock was used in conjunction with an acrylic housing unit to apply pressure along the edge of the channel. The indirect pressure application was successful in promoting vertical fluid flow between layers. Average channel development …

Assessment Of The Correlation Between Memory Span Test Result And Attention Using A Wireless Eeg System, Yu Yu

Theses and Dissertations

The process to encode, retain and retrieve information is known as memory. Ever since models for short-term memory and working memory systems were proposed, the function and importance of the short-term memory and working memory systems have been explored by a number of studies which in part have examined factors which may affect memory capacity. Although there are many undetermined factors which may affect the result of these two different memory span test, recent studies have suggested a link between human mental condition and memory capacity. These studies show that the results of simple memory span tests are improved when …

A Multimodal Investigation In Eye Movements, Raj Jaswal

Dissertations

While functional magnetic resonance imaging (fMRI) has identified which regions of interest (ROIs) are functionally active during a vergence movement (inward or outward eye rotation), task-modulated coactivation between ROIs is less understood. This study tests the following hypotheses: (1) significant task-modulated coactivation would be observed between the frontal eye fields (FEFs), the posterior parietal cortex (PPC), and the cerebellar vermis (CV); (2) significantly more functional activity and task-modulated coactivation would be observed in binocularly normal controls (BNCs) compared with convergence insufficiency (CI) subjects; and (3) after vergence training, the functional activity and task-modulated coactivation would increase in CIs compared with …

Biomimetic And Vascularized 3-D Liver Cancer Model, Derek Yip

Dissertations

Anti-angiogenic drugs have failed to show significant extended mortality, except when co-administered with chemotherapy drugs in clinical trials. This should be predicted by in vitro models, and yet 2D in vitro models of liver cancer co-administered with these two types of drugs show increased cell viability, contradicting clinical trials. In vitro models should mimic clinical trials in order to accurately predict drug outcomes. 2D in vitro models fail because they lack features of the cancer environment such as presence of stromal cells and a vasculature.

In order to achieve a biomimetic and vascularized in vitro model that would better recapitulate …

Fabrication Of 3d Hydrogel-Based Microscale Tissue Analog Chip With Integrated Optofluidics, Venkatakrishnan Rengarajan

Dissertations

Lab-on-a-chip (LOC) is a device that integrates one or more laboratory functions in a single chip with dimensions ranging from a micrometer to a few millimeters. On-chip optofluidics, which combines microfluidics and tunable micro-optical components, is crucial for bio-sensing applications. However, recently reported optofluidic devices have only two-dimensional (2D) dielectric or metallic regions for sensing cellular activity, which fail to mimic the three-dimensional (3D) in vivo microenvironment of cells.

In this research, a 3D hydrogel-based micro-scale-tissue-analog-chip (µTAC) is fabricated with an integrated optofluidic design for biomedical applications. These 3D hydrogels act as a scaffold for the cellular studies and as …

Diffuse Optical Measurements Of Head And Neck Tumor Hemodynamics For Early Prediction Of Chemoradiation Therapy Outcomes, Lixin Dong, Mahesh Kudrimoti, Daniel Irwin, Li Chen, Sameera Kumar, Yu Shang, Chong Huang, Ellis L. Johnson, Scott D. Stevens, Brent J. Shelton, Guoqiang Yu

Biomedical Engineering Faculty Publications

This study used a hybrid near-infrared diffuse optical instrument to monitor tumor hemodynamic responses to chemoradiation therapy for early prediction of treatment outcomes in patients with head and neck cancer. Forty-seven patients were measured once per week to evaluate the hemodynamic status of clinically involved cervical lymph nodes as surrogates for the primary tumor response. Patients were classified into two groups: complete response (CR) (n = 29) and incomplete response (IR) (n = 18). Tumor hemodynamic responses were found to be associated with clinical outcomes (CR/IR), wherein the associations differed depending on human papillomavirus (HPV-16) status. In HPV-16 …