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Full-Text Articles in Biomedical Engineering and Bioengineering

Permanent His Bundle Pacing: Electrophysiological And Echocardiographic Observations From Long-Term Follow-Up, Pugazhendhi Vijayaraman, Gopi Dandamudi, Daniel Lustgarten, Kenneth A. Ellenbogen Jan 2017

Permanent His Bundle Pacing: Electrophysiological And Echocardiographic Observations From Long-Term Follow-Up, Pugazhendhi Vijayaraman, Gopi Dandamudi, Daniel Lustgarten, Kenneth A. Ellenbogen

Biomedical Engineering Publications

Background: Permanent His bundle pacing (HBP) is a physiological alternative to right ventricular pacing. It is not known whether HBP can cause His-Purkinje conduction (HPC) disease. The aim of our study is to assess His bundle capture and its effect on left ventricular (LV) function in long-term follow-up and to determine HPC at the time of pulse generator change (GC) in patients with chronic HBP.

Methods: HB electrograms were recorded from the pacing lead at implant and GC. HBP QRS duration (QRSd), His-ventricular (HV) intervals, and HB pacing thresholds at GC were compared with implant measurements. HPC was assessed by ...


Substrate Stiffness Controls Osteoblastic And Chondrocytic Differentiation Of Mesenchymal Stem Cells Without Exogenous Stimuli, Rene Olivares-Navarrete, Erin M. Lee, Kathryn Smith, Sharon L. Hyzy, Maryam Doroudi, Joseph K. Williams, Ken Gall, Barbara D. Boyan, Zvi Schwartz Jan 2017

Substrate Stiffness Controls Osteoblastic And Chondrocytic Differentiation Of Mesenchymal Stem Cells Without Exogenous Stimuli, Rene Olivares-Navarrete, Erin M. Lee, Kathryn Smith, Sharon L. Hyzy, Maryam Doroudi, Joseph K. Williams, Ken Gall, Barbara D. Boyan, Zvi Schwartz

Biomedical Engineering Publications

Stem cell fate has been linked to the mechanical properties of their underlying substrate, affecting mechanoreceptors and ultimately leading to downstream biological response. Studies have used polymers to mimic the stiffness of extracellular matrix as well as of individual tissues and shown mesenchymal stem cells (MSCs) could be directed along specific lineages. In this study, we examined the role of stiffness in MSC differentiation to two closely related cell phenotypes: osteoblast and chondrocyte. We prepared four methyl acrylate/methyl methacrylate (MA/MMA) polymer surfaces with elastic moduli ranging from 0.1 MPa to 310 MPa by altering monomer concentration. MSCs ...


Predictive Behavior Of A Computational Foot/Ankle Model Through Artificial Neural Networks, Ruchi D. Chande, Rosalyn Hobson Hargraves, Norma Ortiz-Robinson, Jennifer S. Wayne Jan 2017

Predictive Behavior Of A Computational Foot/Ankle Model Through Artificial Neural Networks, Ruchi D. Chande, Rosalyn Hobson Hargraves, Norma Ortiz-Robinson, Jennifer S. Wayne

Biomedical Engineering Publications

Computational models are useful tools to study the biomechanics of human joints. Their predictive performance is heavily dependent on bony anatomy and soft tissue properties. Imaging data provides anatomical requirements while approximate tissue properties are implemented from literature data, when available. We sought to improve the predictive capability of a computational foot/ankle model by optimizing its ligament stiffness inputs using feedforward and radial basis function neural networks. While the former demonstrated better performance than the latter per mean square error, both networks provided reasonable stiffness predictions for implementation into the computational model.


Predictive Behavior Of A Computational Foot/Ankle Model Through Artificial Neural Networks, Ruchi D. Chande, Rosalyn Hobson Hargraves, Norma Ortiz-Robinson, Jennifer S. Wayne Jan 2017

Predictive Behavior Of A Computational Foot/Ankle Model Through Artificial Neural Networks, Ruchi D. Chande, Rosalyn Hobson Hargraves, Norma Ortiz-Robinson, Jennifer S. Wayne

Biomedical Engineering Publications

Computational models are useful tools to study the biomechanics of human joints. Their predictive performance is heavily dependent on bony anatomy and soft tissue properties. Imaging data provides anatomical requirements while approximate tissue properties are implemented from literature data, when available. We sought to improve the predictive capability of a computational foot/ankle model by optimizing its ligament stiffness inputs using feedforward and radial basis function neural networks. While the former demonstrated better performance than the latter per mean square error, both networks provided reasonable stiffness predictions for implementation into the computational model.


Aging Effects On Airflow Dynamics And Lung Function In Human Bronchioles, Jongwon Kim, Rebecca L. Heise, Angela M. Reynolds, Ramana M. Pidaparti Jan 2017

Aging Effects On Airflow Dynamics And Lung Function In Human Bronchioles, Jongwon Kim, Rebecca L. Heise, Angela M. Reynolds, Ramana M. Pidaparti

Biomedical Engineering Publications

Background and objective

The mortality rate for patients requiring mechanical ventilation is about 35% and this rate increases to about 53% for the elderly. In general, with increasing age, the dynamic lung function and respiratory mechanics are compromised, and several experiments are being conducted to estimate these changes and understand the underlying mechanisms to better treat elderly patients.

Materials and methods

Human tracheobronchial (G1 ~ G9), bronchioles (G10 ~ G22) and alveolar sacs (G23) geometric models were developed based on reported anatomical dimensions for a 50 and an 80-year-old subject. The aged model was developed by altering the geometry and material properties ...


Mechanical Loading Attenuates Radiation-Induced Bone Loss In Bone Marrow Transplanted Mice, Peter M. Govey, Yue Zhang, Henry J. Donahue Jan 2016

Mechanical Loading Attenuates Radiation-Induced Bone Loss In Bone Marrow Transplanted Mice, Peter M. Govey, Yue Zhang, Henry J. Donahue

Biomedical Engineering Publications

Exposure of bone to ionizing radiation, as occurs during radiotherapy for some localized malignancies and blood or bone marrow cancers, as well as during space travel, incites dose-dependent bone morbidity and increased fracture risk. Rapid trabecular and endosteal bone loss reflects acutely increased osteoclastic resorption as well as decreased bone formation due to depletion of osteoprogenitors. Because of this dysregulation of bone turnover, boneโ€™s capacity to respond to a mechanical loading stimulus in the aftermath of irradiation is unknown. We employed a mouse model of total body irradiation and bone marrow transplantation simulating treatment of hematologic cancers, hypothesizing that ...


Novel Osteogenic Ti-6al-4v Device For Restoration Of Dental Function In Patients With Large Bone Deficiencies: Design, Development And Implementation, David J. Cohen, A Cheng, A. Kahn, M. Aviram, Alexander J. Whitehead, Sharon Hyzy, Ryan M. Clohessy, Barbara D. Boyan, Zvi Schwartz Jan 2016

Novel Osteogenic Ti-6al-4v Device For Restoration Of Dental Function In Patients With Large Bone Deficiencies: Design, Development And Implementation, David J. Cohen, A Cheng, A. Kahn, M. Aviram, Alexander J. Whitehead, Sharon Hyzy, Ryan M. Clohessy, Barbara D. Boyan, Zvi Schwartz

Biomedical Engineering Publications

Custom devices supporting bone regeneration and implant placement are needed for edentulous patients with large mandibular deficiencies where endosteal implantation is not possible. We developed a novel subperiosteal titanium-aluminum-vanadium bone onlay device produced by additive manufacturing (AM) and post-fabrication osteogenic micro-/nano-scale surface texture modification. Human osteoblasts produced osteogenic and angiogenic factors when grown on laser-sintered nano-/micro-textured surfaces compared to smooth surfaces. Surface-processed constructs caused higher bone-to-implant contact, vertical bone growth into disk pores (microCT and histomorphometry), and mechanical pull-out force at 5 and 10โ€‰w on rat calvaria compared to non surface-modified constructs, even when pre-treating the bone ...


24r,25-Dihydroxyvitamin D3 Protects Against Articular Cartilage Damage Following Anterior Cruciate Ligament Transection In Male Rats, Barbara D. Boyan, Sharon L. Hyzy, Qingfen Pan, Kayla M. Scott, Richard D. Coutts, Robert Healey, Zvi Schwartz Jan 2016

24r,25-Dihydroxyvitamin D3 Protects Against Articular Cartilage Damage Following Anterior Cruciate Ligament Transection In Male Rats, Barbara D. Boyan, Sharon L. Hyzy, Qingfen Pan, Kayla M. Scott, Richard D. Coutts, Robert Healey, Zvi Schwartz

Biomedical Engineering Publications

Osteoarthritis (OA) in humans is associated with low circulating 25-hydroxyvitamin D3 [25 (OH)D3]. In vitamin D replete rats, radiolabeled 24R,25-dihydroxyvitamin D3 [24R,25 (OH)2D3] accumulates in articular cartilage following injection of [3 H]-25(OH)D3. Previously, we showed that 24R,25(OH)2D3 blocks chondrocyte apoptosis via phospholipase D and p53, suggesting a role for 24R,25(OH)2D3 in maintaining cartilage health. We examined the ability of 24R,25(OH)2D3 to prevent degenerative changes in articular cartilage in an OAlike environment and the potential mechanisms involved. In vitro, rat articular chondrocytes were treated with ...


Regulation Of Osteoblast Differentiation By Acid-Etched And/Or Grit-Blasted Titanium Substrate Topography Is Enhanced By 1,25(Oh)2d3 In A Sex-Dependent Manner, Rene Olivares-Navarrete, Sharon L. Hyzy, Barbara D. Boyan, Zvi Schwartz Jan 2015

Regulation Of Osteoblast Differentiation By Acid-Etched And/Or Grit-Blasted Titanium Substrate Topography Is Enhanced By 1,25(Oh)2d3 In A Sex-Dependent Manner, Rene Olivares-Navarrete, Sharon L. Hyzy, Barbara D. Boyan, Zvi Schwartz

Biomedical Engineering Publications

This study assessed contributions of micron-scale topography on clinically relevant titanium (Ti) to differentiation of osteoprogenitor cells and osteoblasts; the interaction of this effect with 1๐›ผ,25-dihydroxyvitamin D3 (1๐›ผ,25(OH)2D3); and if the effects are sex-dependent. Male and female rat bone marrow cells (BMCs) were cultured on acid-etched (A, ๐‘…๐‘Ž = 0.87 ๐œ‡m), grit-blasted (GB, ๐‘…๐‘Ž = 3.90 ๐œ‡m), or grit-blasted/acid-etched (SLA, ๐‘…๐‘Ž = 3.22 ๐œ‡m) Ti. BMCs were sensitive to surface topography and underwent osteoblast differentiation. This was greatest on SLA; acid etching and grit blasting contributed additively. Primary osteoblasts ...


Effect Of Four Approaches To Oral Feeding Progression On Clinical Outcomes In Preterm Infants, Rita H. Pickler, Barbara A. Reyna, Paul A. Wetzel, Mary Lewis Jan 2015

Effect Of Four Approaches To Oral Feeding Progression On Clinical Outcomes In Preterm Infants, Rita H. Pickler, Barbara A. Reyna, Paul A. Wetzel, Mary Lewis

Biomedical Engineering Publications

Background. The purpose of this study of preterm infants was to test the effect of four approaches to the time of transition from gavage to full oral feedings, time to discharge, and weight gain during the transition.Methods. A randomized experimental design was used with four intervention groups: early start (32 weeks' postmenstrual age)/slow progressing experience (gradually increasing oral feedings offered per day); early start/maximum experience (oral feedings offered at every feeding opportunity); late start (34 weeks' postmenstrual age)/slow progressing experience; and late start/maximum experience. Results. The analysis included 86 preterm infants. Once oral feedings were ...


Patterned Feeding Experience For Preterm Infants: Study Protocol For A Randomized Controlled Trial, Rita H. Pickler, Paul A. Wetzel, Jareen Meinzen-Derr, Heather L. Tubbs-Cooley, Margo Moore Jan 2015

Patterned Feeding Experience For Preterm Infants: Study Protocol For A Randomized Controlled Trial, Rita H. Pickler, Paul A. Wetzel, Jareen Meinzen-Derr, Heather L. Tubbs-Cooley, Margo Moore

Biomedical Engineering Publications

Background

Neurobehavioral disabilities occur in 5โ€“15 % of preterm infants with an estimated 50โ€“70 % of very low birth weight preterm infants experiencing later dysfunction, including cognitive, behavioral, and social delays that often persist into adulthood. Factors implicated in poor neurobehavioral and developmental outcomes are hospitalization in the neonatal intensive care unit (NICU) and inconsistent caregiving patterns. Although much underlying brain damage occurs in utero or shortly after birth, neuroprotective strategies can stop lesions from progressing, particularly when these strategies are used during the most sensitive periods of neural plasticity occurring months before term age. The purpose of this randomized ...


Osteogenic Embryoid Body-Derived Material Induces Bone Formation In Vivo, Ken Sutha, Zvi Schwartz, Yun Wang, Sharon Hyzy, Barbara D. Boyan, Todd C. Mcdevitt Jan 2015

Osteogenic Embryoid Body-Derived Material Induces Bone Formation In Vivo, Ken Sutha, Zvi Schwartz, Yun Wang, Sharon Hyzy, Barbara D. Boyan, Todd C. Mcdevitt

Biomedical Engineering Publications

The progressive loss of endogenous regenerative capacity that accompanies mammalian aging has been attributed at least in part to alterations in the extracellular matrix (ECM) composition of adult tissues. Thus, creation of a more regenerative microenvironment, analogous to embryonic morphogenesis, may be achieved via pluripotent embryonic stem cell (ESC) differentiation and derivation of devitalized materials as an alternative to decellularized adult tissues, such as demineralized bone matrix (DBM). Transplantation of devitalized ESC materials represents a novel approach to promote functional tissue regeneration and reduce the inherent batch-to-batch variability of allograft-derived materials. In this study, the osteoinductivity of embryoid body-derived material ...


Frontal Cryosectioning: An Improved Protocol For Sectioning Large Areas Of Fibrous Scaffolds, Casey Grey, David G. Simpson Jan 2015

Frontal Cryosectioning: An Improved Protocol For Sectioning Large Areas Of Fibrous Scaffolds, Casey Grey, David G. Simpson

Biomedical Engineering Publications

Fibrous tissue engineering scaffolds, such as those produced by electrospinning, cannot achieve their clinical potential until deep cell-scaffold interactions are understood. Even the most advanced imaging techniques are limited to capturing data at depths of 100โ€‰ยตm due to light scatter associated with the fibers that compose these scaffolds. Conventional cross-sectional analysis provides information on relatively small volumes of space and frontal sections are difficult to generate. Current understanding of cellular penetration into fibrous scaffolds is limited predominantly to the scaffold surface. Although some information is available from cross-sections, sections vary in quality, can distort spatial scaffold properties, and offer ...


Impaired Bone Formation In Pdia3 Deficient Mice, Yun Wang, Alexandr Nizkorodov, Kelsie Riemenschneider, Christopher S. D. Lee, Rene Olivares-Navarrete, Zvi Schwartz, Barbara D. Boyan Jan 2014

Impaired Bone Formation In Pdia3 Deficient Mice, Yun Wang, Alexandr Nizkorodov, Kelsie Riemenschneider, Christopher S. D. Lee, Rene Olivares-Navarrete, Zvi Schwartz, Barbara D. Boyan

Biomedical Engineering Publications

1ฮฑ,25-dihydroxyvitamin D3 [1ฮฑ,25(OH)2D3] is crucial for normal skeletal development and bone homeostasis. Protein disulfide isomerase family A, member 3 (PDIA3) mediates 1ฮฑ,25(OH)2D3initiated-rapid membrane signaling in several cell types. To understand its role in regulating skeletal development, we generated Pdia3-deficient mice and examined the physiologic consequence of Pdia3-disruption in embryos and Pdia3+/โˆ’ heterozygotes at different ages. No mice homozygous for the Pdia3-deletion were found at birth nor were there embryos after E12.5, indicating that targeted disruption of the Pdia3 gene resulted in early embryonic lethality.Pdia3-deficiency also resulted in ...


Rock Inhibitor Is Not Required For Embryoid Body Formation From Singularized Human Embryonic Stem Cells, Giuseppe Pettinato, Wendy S. Vanden Berg-Foels, Ning Zhang, Xuejun Wen Jan 2014

Rock Inhibitor Is Not Required For Embryoid Body Formation From Singularized Human Embryonic Stem Cells, Giuseppe Pettinato, Wendy S. Vanden Berg-Foels, Ning Zhang, Xuejun Wen

Biomedical Engineering Publications

We report a technology to form human embryoid bodies (hEBs) from singularized human embryonic stem cells (hESCs) without the use of the p160 rho-associated coiled-coil kinase inhibitor (ROCKi) or centrifugation (spin). hEB formation was tested under four conditions: +ROCKi/+spin, +ROCKi/-spin, -ROCKi/+spin, and -ROCKi/-spin. Cell suspensions of BG01V/hOG and H9 hESC lines were pipetted into non-adherent hydrogel substrates containing defined microwell arrays. hEBs of consistent size and spherical geometry can be formed in each of the four conditions, including the -ROCKi/-spin condition. The hEBs formed under the -ROCKi/-spin condition differentiated to develop the three ...


A Novel Myoelectric Training Device For Upper Limb Prostheses, Ryan Clingman, Peter Pidcoe Jan 2014

A Novel Myoelectric Training Device For Upper Limb Prostheses, Ryan Clingman, Peter Pidcoe

Biomedical Engineering Publications

A training system intended for myoelectric prosthetic hands for upper limb amputees was developed to assist in learning myoelectric control schemes and training muscle isolation. The trainer allowed a user to operate a remote controlled car by use of a control scheme commonly used in myoelectric prosthetic hands. The trainer was designed to be easy for therapists to use and more engaging for the user than current methods of signal training. Preliminary testing of the trainer was conducted with eight nonamputee adult volunteers. The results indicated that the trainer could be a useful tool for myoelectric training in upper limb ...


Amelogenin Peptide Extract Increases Differentiation And Angiogenic And Local Factor Production And Inhibits Apoptosis In Human Osteoblasts, Rene Olivares-Navarrete, Sharon L. Hyzy, Argelia Almaguer-Flores, Corinna Mauth, Anja C. Gemperli, Barbara D. Boyan, Zvi Schwartz Jan 2013

Amelogenin Peptide Extract Increases Differentiation And Angiogenic And Local Factor Production And Inhibits Apoptosis In Human Osteoblasts, Rene Olivares-Navarrete, Sharon L. Hyzy, Argelia Almaguer-Flores, Corinna Mauth, Anja C. Gemperli, Barbara D. Boyan, Zvi Schwartz

Biomedical Engineering Publications

Enamel matrix derivative (EMD), a decellularized porcine extracellular matrix (ECM), is used clinically in periodontal tissue regeneration. Amelogenin, EMDโ€™s principal component, spontaneously assembles into nanospheres in vivo, forming an ECM complex that releases proteolytically cleaved peptides. However, the role of amelogenin or amelogenin peptides in mediating osteoblast response to EMD is not clear. Human MG63 osteoblast-like cells or normal human osteoblasts were treated with recombinant human amelogenin or a 5โ€‰kDa tyrosine-rich amelogenin peptide (TRAP) isolated from EMD and the effect on osteogenesis, local factor production, and apoptosis assessed. Treated MG63 cells increased alkaline phosphatase specific activity and levels ...


A Preliminary Study On The Potential Of Manuka Honey And Platelet-Rich Plasma In Wound Healing, Scott A. Sell, Patricia Wolfe, Andrew J. Spence, Isaac Rodriguez, Jennifer M. Mccool, Rebecca L. Petrella, Koyal Garg, Jeffery J. Ericksen, Gary L. Bowlin Jan 2012

A Preliminary Study On The Potential Of Manuka Honey And Platelet-Rich Plasma In Wound Healing, Scott A. Sell, Patricia Wolfe, Andrew J. Spence, Isaac Rodriguez, Jennifer M. Mccool, Rebecca L. Petrella, Koyal Garg, Jeffery J. Ericksen, Gary L. Bowlin

Biomedical Engineering Publications

Aim. The purpose of this study was to determine the in vitro response of cells critical to the wound healing process in culture media supplemented with a lyophilized preparation rich in growth factors (PRGF) and Manuka honey. Materials and Methods. This study utilized cell culture media supplemented with PRGF, as well as whole Manuka honey and the medical-grade Medihoney (MH), a Manuka honey product. The response of human fibroblasts (hDF), macrophages, and endothelial cells (hPMEC) was evaluated, with respect to cell proliferation, chemotaxis, collagen matrix production, and angiogenic potential, when subjected to culture with media containing PRGF, MH, Manuka honey ...


Mineralization Potential Of Electrospun Pdo-Hydroxyapatite-Fibrinogen Blended Scaffolds, Isaac Rodriguez, Parthasarathy A. Madurantakam, Jennifer M. Mccool, Scott A. Sell, Hu Yang, Peter C. Moon, Gary L. Bowlin Jan 2012

Mineralization Potential Of Electrospun Pdo-Hydroxyapatite-Fibrinogen Blended Scaffolds, Isaac Rodriguez, Parthasarathy A. Madurantakam, Jennifer M. Mccool, Scott A. Sell, Hu Yang, Peter C. Moon, Gary L. Bowlin

Biomedical Engineering Publications

The current bone autograft procedure for cleft palate repair presents several disadvantages such as limited availability, additional invasive surgery, and donor site morbidity. The present preliminary study evaluates the mineralization potential of electrospun polydioxanone:nano-hydroxyapatiteโ€‰:โ€‰fibrinogen (PDOโ€‰:โ€‰nHAโ€‰:โ€‰Fg) blended scaffolds in different simulated body fluids (SBF). Scaffolds were fabricated by blending PDOโ€‰:โ€‰nHAโ€‰:โ€‰Fg in the following percent by weight ratios: 100โ€‰:โ€‰0โ€‰:โ€‰0, 50โ€‰:โ€‰25โ€‰:โ€‰25, 50โ€‰:โ€‰50โ€‰:โ€‰0, 50โ€‰:โ€‰0โ€‰:โ€‰50, 0โ€‰:โ€‰0โ€‰:โ€‰100, and 0โ€‰:โ€‰50โ€‰:โ€‰50. Samples were immersed in (conventional (c), revised (r), ionic (i), and modified (m)) SBF for 5 and 14 days ...


A Binary Method For Simple And Accurate Two-Dimensional Cursor Control From Eeg With Minimal Subject Training, Turan A. Kayagil, Ou Bai, Craig S. Henriquez, Peter Lin, Stephen J. Furlani, Sherry Vorbach, Mark Hallett Jan 2009

A Binary Method For Simple And Accurate Two-Dimensional Cursor Control From Eeg With Minimal Subject Training, Turan A. Kayagil, Ou Bai, Craig S. Henriquez, Peter Lin, Stephen J. Furlani, Sherry Vorbach, Mark Hallett

Biomedical Engineering Publications

Background

Brain-computer interfaces (BCI) use electroencephalography (EEG) to interpret user intention and control an output device accordingly. We describe a novel BCI method to use a signal from five EEG channels (comprising one primary channel with four additional channels used to calculate its Laplacian derivation) to provide two-dimensional (2-D) control of a cursor on a computer screen, with simple threshold-based binary classification of band power readings taken over pre-defined time windows during subject hand movement.

Methods

We tested the paradigm with four healthy subjects, none of whom had prior BCI experience. Each subject played a game wherein he or she ...