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Biomedical Engineering and Bioengineering Commons™
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Articles 661 - 690 of 723
Full-Text Articles in Biomedical Engineering and Bioengineering
A Real-Time Haptic/Graphic Demonstration Of How Error Augmentation Can Enhance Learning, Yejun Wei, James L. Patton, Preeti Bajaj, Robert A. Scheidt
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 …
Quantitative Models Of The Rat Pulmonary Arterial Tree Morphometry Applied To Hypoxia-Induced Arterial Remodeling, Robert C. Molthen, Kelly L. Karau, Christopher A. Dawson
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 …
Cardioprotection By Glucose-Insulin-Potassium: Dependence On KAtp Channel Opening And Blood Glucose Concentration Before Ischemia, John F. Ladisa, John G. Krolikowski, Paul S. Pagel, David C. Warltier, Judy R. Kersten
Cardioprotection By Glucose-Insulin-Potassium: Dependence On KAtp Channel Opening And Blood Glucose Concentration Before Ischemia, John F. Ladisa, John G. Krolikowski, Paul S. Pagel, David C. Warltier, Judy R. Kersten
Biomedical Engineering Faculty Research and Publications
We tested the hypothesis that glucose-insulin-potassium (GIK)-induced protection against myocardial infarction depends on ATP-dependent K+ (KATP) channel activation and is abolished by hyperglycemia before the ischemia. Dogs were subjected to a 60-min coronary artery occlusion and 3-h reperfusion in the absence or presence of GIK (25% dextrose; 50 IU insulin/l; 80 mM/l KCl infused at 1.5 ml·kg−1·h−1) beginning 75 min before coronary artery occlusion or 5 min before reperfusion. The role of KATP channels was evaluated by pretreatment with glyburide (0.1 mg/kg). The efficacy of GIK was investigated with increases in blood …
Impact Of Pulmonary Arterial Endothelial Cells On Duroquinone Redox Status, Marilyn P. Merker, Robert D. Bongard, Gary S. Krenz, Hongtao Zhao, Viola S. Fernandes, Balaraman Kalyanaraman, Neil Hogg, Said H. Audi
Impact Of Pulmonary Arterial Endothelial Cells On Duroquinone Redox Status, Marilyn P. Merker, Robert D. Bongard, Gary S. Krenz, Hongtao Zhao, Viola S. Fernandes, Balaraman Kalyanaraman, Neil Hogg, Said H. Audi
Biomedical Engineering Faculty Research and Publications
The study objective was to use pulmonary arterial endothelial cells to examine kinetics and mechanisms contributing to the disposition of the quinone 2,3,5,6-tetramethyl-1,4-benzoquinone (duroquinone, DQ) observed during passage through the pulmonary circulation. The approach was to add DQ, durohydroquinone (DQH2), or DQ with the cell membrane-impermeant oxidizing agent, ferricyanide (Fe(CN)63−), to the cell medium, and to measure the medium concentrations of substrates and products over time. Studies were carried out under control conditions and with dicumarol, to inhibit NAD(P)H:quinone oxidoreductase 1 (NQO1), or cyanide, to inhibit mitochondrial electron transport. In control cells, DQH2 appears …
Effect Of Ventilation Rate On Instilled Surfactant Distribution In The Pulmonary Airways Of Rats, Joseph C. Anderson, Robert C. Molthen, Christopher A. Dawson, Steven Thomas Haworth, Joseph L. Bull, Matthew R. Glucksburg, James B. Grotberg
Effect Of Ventilation Rate On Instilled Surfactant Distribution In The Pulmonary Airways Of Rats, Joseph C. Anderson, Robert C. Molthen, Christopher A. Dawson, Steven Thomas Haworth, Joseph L. Bull, Matthew R. Glucksburg, James B. Grotberg
Biomedical Engineering Faculty Research and Publications
Liquid can be instilled into the pulmonary airways during medical procedures such as surfactant replacement therapy, partial liquid ventilation, and pulmonary drug delivery. For all cases, understanding the dynamics of liquid distribution in the lung will increase the efficacy of treatment. A recently developed imaging technique for the study of real-time liquid transport dynamics in the pulmonary airways was used to investigate the effect of respiratory rate on the distribution of an instilled liquid, surfactant, in a rat lung. Twelve excised rat lungs were suspended vertically, and a single bolus (0.05 ml) of exogenous surfactant (Survanta, Ross Laboratories, Columbus, OH) …
Stent Design Properties And Deployment Ratio Influence Indexes Of Wall Shear Stress: A Three-Dimensional Computational Fluid Dynamics Investigation Within A Normal Artery, John F. Ladisa, Lars E. Olson, Ismail Guler, Douglas Anthony Hettrick, Said H. Audi, Judy R. Kersten, David C. Warltier, Paul S. Pagel
Stent Design Properties And Deployment Ratio Influence Indexes Of Wall Shear Stress: A Three-Dimensional Computational Fluid Dynamics Investigation Within A Normal Artery, John F. Ladisa, Lars E. Olson, Ismail Guler, Douglas Anthony Hettrick, Said H. Audi, Judy R. Kersten, David C. Warltier, Paul S. Pagel
Biomedical Engineering Faculty Research and Publications
Restenosis limits the effectiveness of stents, but the mechanisms responsible for this phenomenon remain incompletely described. Stent geometry and expansion during deployment produce alterations in vascular anatomy that may adversely affect wall shear stress (WSS) and correlate with neointimal hyperplasia. These considerations have been neglected in previous computational fluid dynamics models of stent hemodynamics. Thus we tested the hypothesis that deployment diameter and stent strut properties (e.g., number, width, and thickness) influence indexes of WSS predicted with three-dimensional computational fluid dynamics. Simulations were based on canine coronary artery diameter measurements. Stent-to-artery ratios of 1.1 or 1.2:1 were modeled, and computational …
Computerized Biofeedback Knee Goniometer: Acceptance And Effect On Exercise Behavior In Post-Total Knee Arthroplasty Rehabilitation, Todd A. Kuiken, Hagay Amir, Robert A. Scheidt
Computerized Biofeedback Knee Goniometer: Acceptance And Effect On Exercise Behavior In Post-Total Knee Arthroplasty Rehabilitation, Todd A. Kuiken, Hagay Amir, Robert A. Scheidt
Biomedical Engineering Faculty Research and Publications
Objective
To assess device accuracy, patient acceptance, and effect of a computerized biofeedback knee goniometer (CBG), on patients’ compliance with active range of motion (AROM) exercises after total knee arthroplasty (TKA).
Design
Two-stage study: measurement validation on asymptomatic controls and an unblinded, multiple crossover trial.
Setting
Inpatient rehabilitation.
Participants
Asymptomatic controls (n=14) and post-TKA inpatients (n=11).
Interventions
For measurement validation, CBG-angle measurements were compared with manual, clinician-obtained angles. To assess motivational effect, the CBG was worn after TKA; on alternating days, it either monitored AROM silently (no feedback) or provided audiovisual feedback about reaching preset range of motion (ROM) goals …
Geometry Analysis Of An Inverse-Geometry Volumetric Ct System With Multiple Detector Arrays, Samuel R. Mazin, Taly Gilat Schmidt, Edward G. Solomon, Rebecca Fahrig, Norbert J. Pelc
Geometry Analysis Of An Inverse-Geometry Volumetric Ct System With Multiple Detector Arrays, Samuel R. Mazin, Taly Gilat Schmidt, Edward G. Solomon, Rebecca Fahrig, Norbert J. Pelc
Biomedical Engineering Faculty Research and Publications
An inverse-geometry volumetric CT (IGCT) system for imaging in a single fast rotation without cone-beam artifacts is being developed. It employs a large scanned source array and a smaller detector array. For a single-source/single-detector implementation, the FOV is limited to a fraction of the source size. Here we explore options to increase the FOV without increasing the source size by using multiple detectors spaced apart laterally to increase the range of radial distances sampled. We also look at multiple source array systems for faster scans. To properly reconstruct the FOV, Radon space must be sufficiently covered and sampled in a …
Changes In Pulmonary Arterial Wall Mechanical Properties And Lumenal Architecture With Induced Vascular Remodeling, Robert C. Molthen, Amy Heinrich, Steven Thomas Haworth, Christopher A. Dawson
Changes In Pulmonary Arterial Wall Mechanical Properties And Lumenal Architecture With Induced Vascular Remodeling, Robert C. Molthen, Amy Heinrich, Steven Thomas Haworth, Christopher A. Dawson
Biomedical Engineering Faculty Research and Publications
To explore and quantify pulmonary arterial remodeling we used various methods including micro-CT, high-resolution 3-dimensional x-ray imaging, to examine the structure and function of intact pulmonary vessels in isolated rat lungs. The rat is commonly used as an animal model for studies of pulmonary hypertension (PH) and the accompanying vascular remodeling, where vascular remodeling has been defined primarily by changes in the vessel wall composition in response to hypertension inducing stimuli such as chronic hypoxic exposure (CHE) or monocrotaline (MCT) injection. Little information has been provided as to how such changes affect the vessel wall mechanical properties or the lumenal …
Quantification Of Bronchial Circulation Perfusion In Rats, Christian Wieholt, Robert C. Molthen, Steven Thomas Haworth, David L. Roerig, Christopher A. Dawson, Anne V. Clough
Quantification Of Bronchial Circulation Perfusion In Rats, Christian Wieholt, Robert C. Molthen, Steven Thomas Haworth, David L. Roerig, Christopher A. Dawson, Anne V. Clough
Biomedical Engineering Faculty Research and Publications
The bronchial circulation is thought to be the primary blood supply for pulmonary carcinomas. Thus, we have developed a method for imaging and quantifying changes in perfusion in the rat lung due to development of the bronchial circulation. A dual-modality micro-CT/SPECT system was used to detect change in perfusion in two groups of rats: controls and those with a surgically occluded left pulmonary artery. Both groups were imaged following injections on separate days i) 2mCi of Tc99m labeled macroaggregated albumin (MAA) into the left carotid artery (IA) and ii) a similar injection into the femoral vein (IV). The IA injection …
Post-Acquisition Small-Animal Respiratory Gated Imaging Using Micro Cone-Beam Ct, Jicun Hu, Steven Thomas Haworth, Robert C. Molthen, Christopher A. Dawson
Post-Acquisition Small-Animal Respiratory Gated Imaging Using Micro Cone-Beam Ct, Jicun Hu, Steven Thomas Haworth, Robert C. Molthen, Christopher A. Dawson
Biomedical Engineering Faculty Research and Publications
On many occasions, it is desirable to image lungs in vivo to perform a pulmonary physiology study. Since the lungs are moving, gating with respect to the ventilatory phase has to be performed in order to minimize motion artifacts. Gating can be done in real time, similar to cardiac imaging in clinical applications, however, there are technical problems that have lead us to investigate different approaches. The problems include breath-to-breath inconsistencies in tidal volume, which makes the precise detection of ventilatory phase difficult, and the relatively high ventilation rates seen in small animals (rats and mice have ventilation rates in …
Noise Simulations For An Inverse-Geometry Volumetric Ct System, Taly Gilat Schmidt, Rebecca Fahrig, Norbert J. Pelc
Noise Simulations For An Inverse-Geometry Volumetric Ct System, Taly Gilat Schmidt, Rebecca Fahrig, Norbert J. Pelc
Biomedical Engineering Faculty Research and Publications
This paper examines the noise performance of an inverse-geometry volumetric CT (IGCT) scanner through simulations. The IGCT system uses a large area scanned source and a smaller array of detectors to rapidly acquire volumetric data with negligible cone-beam artifacts. The first investigation compares the photon efficiency of the IGCT geometry to a 2D parallel ray system. The second investigation models the photon output of the IGCT source and calculates the expected noise. For the photon efficiency investigation. the same total number of photons was modeled in an IGCT acquisition and a comparable multi-slice 2D parallel ray acquisition. For both cases …
Influence Of Isoflurane On Left Atrial Function In Dogs With Pacing-Induced Cardiomyopathy: Evaluation With Pressure-Volume Relationships, Franz Kehl, John F. Ladisa, Douglas Anthony Hettrick, Judy R. Kersten, David C. Warltier, Paul S. Pagel
Influence Of Isoflurane On Left Atrial Function In Dogs With Pacing-Induced Cardiomyopathy: Evaluation With Pressure-Volume Relationships, Franz Kehl, John F. Ladisa, Douglas Anthony Hettrick, Judy R. Kersten, David C. Warltier, Paul S. Pagel
Biomedical Engineering Faculty Research and Publications
Objective
The actions of volatile anesthetics on left ventricular (LV) function in normal and failing hearts have been previously evaluated, but the effects of these agents on left atrial (LA) function in the presence of LV dysfunction are unknown. The hypothesis was tested that isoflurane alters LA mechanics evaluated with pressure-volume relations.
Design
Prospective.
Setting
Laboratory.
Participants
Barbiturate-anesthetized dogs (n = 8) were instrumented for measurement of aortic, LA, and LV pressures (micromanometers), and LA volume (epicardial orthogonal sonomicrometers) after 3 weeks of rapid ventricular pacing (220 beats/min).
Interventions
LA myocardial contractility (Ees) was assessed with end-systolic pressure-volume …
Reactive Oxygen Species Modulate Coronary Wall Shear Stress And Endothelial Function During Hyperglycemia, Eric R. Gross, John F. Ladisa, Dorothee Weihrauch, Lars E. Olson, Tobias T. Kress, Douglas Anthony Hettrick, Paul S. Pagel, David C. Warltier, Judy R. Kersten
Reactive Oxygen Species Modulate Coronary Wall Shear Stress And Endothelial Function During Hyperglycemia, Eric R. Gross, John F. Ladisa, Dorothee Weihrauch, Lars E. Olson, Tobias T. Kress, Douglas Anthony Hettrick, Paul S. Pagel, David C. Warltier, Judy R. Kersten
Biomedical Engineering Faculty Research and Publications
Hyperglycemia is associated with generation of reactive oxygen species (ROS), and this action may contribute to accelerated atherogenesis. We tested the hypothesis that hyperglycemia produces alterations in left anterior descending coronary artery (LAD) wall shear stress concomitant with endothelial dysfunction and ROS production in dogs (n = 12) instrumented for measurement of LAD blood flow, velocity, and diameter. Dogs were randomly assigned to receive vehicle (0.9% saline) or the superoxide dismutase mimetic 4- hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (tempol) and were administered intravenous infusions of d-glucose to achieve target blood glucose concentrations of 350 and 600 mg/dl (moderate and severe hyperglycemia, respectively). Endothelial …
Adenosine Type 1 (A ) Receptors Mediate Protection Against Myocardial 1 Infarction Produced By Chronic, Intermittent Ingestion Of Ethanol In Dogs, Franz Kehl, John G. Krolikowski, John F. Ladisa, Judy R. Kersten, David C. Warltier, Paul S. Pagel
Adenosine Type 1 (A ) Receptors Mediate Protection Against Myocardial 1 Infarction Produced By Chronic, Intermittent Ingestion Of Ethanol In Dogs, Franz Kehl, John G. Krolikowski, John F. Ladisa, Judy R. Kersten, David C. Warltier, Paul S. Pagel
Biomedical Engineering Faculty Research and Publications
Background: Chronic consumption of small amounts of ethanol protects myocardium from ischemic injury. We tested the hypothesis that adenosine type 1 (A1) receptors mediate these beneficial effects.
Methods: Dogs (n=37) were fed with ethanol (1.5 g/kg) or water mixed with dry food twice per day for 12 weeks, fasted overnight before experimentation, and instrumented for measurement of hemodynamics. Dogs received intravenous drug vehicle (50% polyethylene glycol in 0.1 N sodium hydroxide and 0.9% saline over 15 min) or the selective A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 0.8 mg/kg over 15 min) and were subjected …
Nonlinear Elastic Material Property Estimation Of Lower Extremity Residual Limb Tissues, Ergin TöNüK, M. Barbara Silver-Thorn
Nonlinear Elastic Material Property Estimation Of Lower Extremity Residual Limb Tissues, Ergin TöNüK, M. Barbara Silver-Thorn
Biomedical Engineering Faculty Research and Publications
The interface stresses between the residual limb and prosthetic socket have been studied to investigate prosthetic fit. Finite-element models of the residual limb-prosthetic socket interface facilitate investigation of the mechanical interface and may serve as a potential tool for future prosthetic socket design. However, the success of such residual limb models to date has been limited, in large part due to inadequate material formulations used to approximate the mechanical behavior of residual limb soft tissues. Nonlinear finite-element analysis was used to simulate force-displacement data obtained during in vivo rate-controlled (1, 5, and 10 mm/s) cyclic indentation of the residual limb …
Measuring The Effect Of Airway Pressure On Pulmonary Arterial Diameter In The Intact Rat Lung, Robert C. Molthen, Steven Thomas Haworth, Amy Heinrich, Christopher A. Dawson
Measuring The Effect Of Airway Pressure On Pulmonary Arterial Diameter In The Intact Rat Lung, Robert C. Molthen, Steven Thomas Haworth, Amy Heinrich, Christopher A. Dawson
Biomedical Engineering Faculty Research and Publications
To study the relationship between transpulomnary [sic] pressure (Ptp), intravascular pressure (Pv), and the pulmonary arterial tree structure, morphometric measurements of pulmonary arterial trees were made in intact lungs from Sprague-Dawley rats. Using cone beam micro-CT and techniques we developed for imaging small animal lungs, volumetric CT data were acquired for Ptp from 0 - 12 mmHg and Pv from 5 - 30 mmHg. The diameter, D (measured range approximately 0.08-2.0 mm), vs. pressure, P, relation can be described by D(P) = D(0)(1+ α P), where α is a distensibility coefficient. Unlike studies performed in larger animals, where changes in …
Spect Imaging Of Pulmonary Blood Flow In A Rat, Christian Wieholt, Robert C. Molthen, Roger H. Johnson, Christopher A. Dawson, Anne V. Clough
Spect Imaging Of Pulmonary Blood Flow In A Rat, Christian Wieholt, Robert C. Molthen, Roger H. Johnson, Christopher A. Dawson, Anne V. Clough
Biomedical Engineering Faculty Research and Publications
Small animal imaging is experiencing rapid development due to its importance in providing high-throughput phenotypic data for functional genomics studies. We have developed a single photon emission computed tomography (SPECT) system to image the pulmonary perfusion distribution in the rat. A standard gamma camera, equipped with a pinhole collimator, was used to acquire SPECT projection images at 40 sec/view of the rat thorax following injection of Tc99m labeled albumin that accumulated in the rat's lungs. A voxel-driven, ordered-subset expectation maximization reconstruction was implemented. Following SPECT imaging, the rat was imaged using micro-CT with Feldkamp conebeam reconstruction. The two reconstructed image …
Mechanisms Of Volatile Anesthetic-Induced Myocardial Protection, Lynda M. Ludwig, Judy R. Kersten, Katsuya Tanaka, Weidong Gu, John F. Ladisa, David C. Warltier, Paul S. Pagel
Mechanisms Of Volatile Anesthetic-Induced Myocardial Protection, Lynda M. Ludwig, Judy R. Kersten, Katsuya Tanaka, Weidong Gu, John F. Ladisa, David C. Warltier, Paul S. Pagel
Biomedical Engineering Faculty Research and Publications
Volatile anesthetics protect myocardium against reversible and irreversible ischemic injury. Experimental evidence from several in vitro and in vivo animal models demonstrates that volatile agents enhance the recovery of stunned myocardium and reduce the size of myocardial infarction after brief or prolonged coronary artery occlusion and reperfusion, respectively. This protective effect persists after the anesthetic has been discontinued, a phenomenon known as anesthetic-induced preconditioning (APC). Recent clinical data also demonstrates evidence of APC in patients during cardiac surgery. Thus, administration of volatile anesthetics may represent a novel therapeutic approach that reduces morbidity and mortality associated with perioperative myocardial ischemia and …
Three-Dimensional Reconstruction Algorithm For A Reverse-Geometry Volumetric Ct System With A Large-Array Scanned Source, Taly Gilat Schmidt, Rebecca Fahrig, Norbert J. Pelc
Three-Dimensional Reconstruction Algorithm For A Reverse-Geometry Volumetric Ct System With A Large-Array Scanned Source, Taly Gilat Schmidt, Rebecca Fahrig, Norbert J. Pelc
Biomedical Engineering Faculty Research and Publications
We have proposed a CT system design to rapidly produce volumetric images with negligible cone beam artifacts. The investigated system uses a large array scanned source with a smaller array of fast detectors. The x-ray source is electronically steered across a 2D target every few milliseconds as the system rotates. The proposed reconstruction algorithm for this system is a modified 3D filtered backprojection method. The data are rebinned into 2D parallel ray projections, most of which are tilted with respect to the axis of rotation. Each projection is filtered with a 2D kernel and backprojected onto the desired image matrix. …
Sensitivity To Hand Path Curvature During Reaching, Kyle P. Lillis, Robert A. Scheidt
Sensitivity To Hand Path Curvature During Reaching, Kyle P. Lillis, Robert A. Scheidt
Biomedical Engineering Faculty Research and Publications
People optimize reaching to make straight and smooth movements. We performed experiments characterizing human sensitivity to hand path deviations from a straight reach. Vision of the arm was blocked. Subjects either moved the hand along paths of constrained curvature, or a robot moved the relaxed limb along similar trajectories (active and passive conditions, respectively). Subjects responded after each trial whether or not they thought the movement curved convex right. In a series of three experiments, we tested the effects of modifying visual feedback of hand position to suppress curvature, isotonic muscle activation, and a distracter task on subjects ability to …
Mechanism Of Preconditioning By Isoflurane In Rabbits: A Direct Role For Reactive Oxygen Species, Katsuya Tanaka, Dorothee Weihrauch, Franz Kehl, Lynda M. Ludwig, John F. Ladisa, Judy R. Kersten, Paul S. Pagel, David C. Warltier
Mechanism Of Preconditioning By Isoflurane In Rabbits: A Direct Role For Reactive Oxygen Species, Katsuya Tanaka, Dorothee Weihrauch, Franz Kehl, Lynda M. Ludwig, John F. Ladisa, Judy R. Kersten, Paul S. Pagel, David C. Warltier
Biomedical Engineering Faculty Research and Publications
LARGE quantities of reactive oxygen species (ROS) released during reperfusion after coronary artery occlusion damage proteins responsible for intracellular homeostasis, produce tissue injury, depress contractile function, and increase myocardial infarct size. In contrast, small quantities of ROS may exert beneficial effects during ischemia and reperfusion when released before a prolonged ischemic event. ROS derived from mitochondria during a brief ischemic episode produce preconditioning. Free radical scavengers administered during ischemic preconditioning (IPC) markedly attenuate the protective effect of the preconditioning stimulus on infarct size. These data suggest that IPC is mediated in part by small quantities of ROS released during preconditioning. …
A Rehabilitation Engineering Course For Biomedical Engineers, M. Barbara Silver-Thorn
A Rehabilitation Engineering Course For Biomedical Engineers, M. Barbara Silver-Thorn
Biomedical Engineering Faculty Research and Publications
This paper describes an upper division elective course in rehabilitation engineering that addresses prosthetics and orthotics, wheelchair design, seating and positioning, and automobile modifications for individuals with disabilities. Faculty lectures are enhanced by guest lectures and class field trips. Guest lecturers include a prosthetist and a lower extremity amputee client, an engineer/prosthetist specializing in the upper extremity, and a rehabilitation engineer. The lower extremity prosthetist and his client present a case study for prosthetic prescription, fabrication, fitting, alignment, and evaluation. The engineer/prosthetist contrasts body-powered versus externally powered upper extremity prostheses and associated design, fitting, and functional considerations; he also discusses …
Evaluation Of 70/30 D,L-Pla For Use As A Resorbable Interbody Fusion Cage, Jeffrey M. Toth, Mei Wang, Jeffrey L. Scifert, G. Bryan Cornwall, Bradley T. Estes, Howard Seim, Simon Turner
Evaluation Of 70/30 D,L-Pla For Use As A Resorbable Interbody Fusion Cage, Jeffrey M. Toth, Mei Wang, Jeffrey L. Scifert, G. Bryan Cornwall, Bradley T. Estes, Howard Seim, Simon Turner
Biomedical Engineering Faculty Research and Publications
Titanium lumbar interbody spinal fusion devices are reported to be 90% effective for single-level lumbar interbody fusion, although radiographic determination of fusion has been debated. Using blinded radiographic, biomechanic, histologic, and statistical measures, researchers in the present study evaluated a radiolucent 70/30 poly(L-lactide-co-D,L-lactide) (70/30 D,L-PLa) interbody fusion device packed with autograft or rhBMP-2 on a collagen sponge in 25 sheep at 3, 6, 12, 18, and 24 months. A trend of increased fusion stiffness, radiographic fusion, and histologic fusion was demonstrated from 3 months to 24 months. Device degradation was associated with a mild to moderate chronic inflammatory response at …
Investigation Of Lower-Limb Tissue Perfusion During Loading, Barbara Silver-Thorn
Investigation Of Lower-Limb Tissue Perfusion During Loading, Barbara Silver-Thorn
Biomedical Engineering Faculty Research and Publications
An extant tissue indentor used for amputee residual limb tissue indentation studies was modified to include laser Doppler flowmetry (LDF) to enable measurement of tissue perfusion during indentation. This device allows quantitative assessment of the mechanical and physiological response of soft tissues to load, as demonstrated by indentation studies of the lower-limb tissues of young healthy subjects. Potential measures of interest include the relative change in tissue perfusion with load and the time delays associated with the perfusion response during tissue loading and unloading. Such measures may prove useful in future studies of residual limb tissues, improving our understanding of …
An Automated Coronary Artery Occlusion Device For Stimulating Collateral Development In Vivo, Richard Rys, John F. Ladisa, John P. Tessmer, Weidong Gu, Judy R. Kersten, David C. Warltier, Paul S. Pagel
An Automated Coronary Artery Occlusion Device For Stimulating Collateral Development In Vivo, Richard Rys, John F. Ladisa, John P. Tessmer, Weidong Gu, Judy R. Kersten, David C. Warltier, Paul S. Pagel
Biomedical Engineering Faculty Research and Publications
Introduction: Repetitive, brief coronary artery occlusions produce collateral development in experimental animals. This model causes coronary collateralization in a highly reproducible fashion, but the process is very labor intensive. We report the design and use of a fully automated hydraulic coronary occlusion device capable of producing repetitive coronary occlusions and enhancement of coronary collateral development in dogs.
Methods: The device consists of analog electronics that allow adjustment of occlusion number, frequency, pressure and duration, and mechanical components responsible for the coronary occlusion. The motor and piston of the device are coupled to a chronically implanted hydraulic vascular occluder …
Point Of View: Artificial Intervertebral Disc Replacement Using Bioactive Three-Dimensional Fabric, Jeffrey M. Toth
Point Of View: Artificial Intervertebral Disc Replacement Using Bioactive Three-Dimensional Fabric, Jeffrey M. Toth
Biomedical Engineering Faculty Research and Publications
No abstract provided.
Histologic Evaluation Of The Efficacy Of Rhbmp-2 Compared With Autograft Bone In Sheep Spinal Anterior Interbody Fusion, Harvinder Sandhu, Jeffrey M. Toth, Ashish Diwan, H. B. Seim Iii, Linda E.A. Kanim, J. Michael Kabo, A. Simon Turner
Histologic Evaluation Of The Efficacy Of Rhbmp-2 Compared With Autograft Bone In Sheep Spinal Anterior Interbody Fusion, Harvinder Sandhu, Jeffrey M. Toth, Ashish Diwan, H. B. Seim Iii, Linda E.A. Kanim, J. Michael Kabo, A. Simon Turner
Biomedical Engineering Faculty Research and Publications
Study Design. The sheep anterior lumbar spinal fusion model was used to study the efficacy of recombinant human bone morphogenetic protein-2 (rhBMP-2)–collagen composite in comparison with autograft to enhance spinal interbody fusion. Comparisons were drawn from temporal radiographic and end-point biomechanical and histologic data.
Objective. To analyze histologically the ability of rhBMP-2 to achieve complete arthrodesis between vertebral bodies.
Summary of Background Data. Studies using rhBMP for enhancement of anterior interbody fusion have used numerous endpoints. However, systematic histologic evaluation of the fusion has not been conducted.
Methods. Twelve sheep underwent single-level anterior lumbar interbody fusion performed with a cylindrical …
Estimation Of Pulmonary Arterial Volume Changes In The Normal And Hypertensive Fawn-Hooded Rat From 3d Micro-Ct Data, Robert C. Molthen, Christian Wieholt, Steven Thomas Haworth, Christopher A. Dawson
Estimation Of Pulmonary Arterial Volume Changes In The Normal And Hypertensive Fawn-Hooded Rat From 3d Micro-Ct Data, Robert C. Molthen, Christian Wieholt, Steven Thomas Haworth, Christopher A. Dawson
Biomedical Engineering Faculty Research and Publications
In the study of pulmonary vascular remodeling, much can be learned from observing the morphological changes undergone in the pulmonary arteries of the rat lung when exposed to chronic hypoxia or other challenges which elicit a remodeling response. Remodeling effects include thickening of vessel walls, and loss of wall compliance. Morphometric data can be used to localize the hemodynamic and functional consequences. We developed a CT imaging method for measuring the pulmonary arterial tree over a range of pressures in rat lungs. X-ray micro-focal isotropic volumetric imaging of the arterial tree in the intact rat lung provides detailed information on …
Reengineering Biomedical Engineering Curricula: A New Product Development Approach, Robert A. Scheidt, L. Waples, Kristina M. Ropella
Reengineering Biomedical Engineering Curricula: A New Product Development Approach, Robert A. Scheidt, L. Waples, Kristina M. Ropella
Biomedical Engineering Faculty Research and Publications
Product development engineers in medical industries have created design control procedures to ensure high quality designs that are as error-free as possible. The reason is simple; companies must adhere to certain engineering and manufacturing "best practices" in order to obtain certification of their devices for sale in the US and abroad. We describe here an ongoing effort to apply these industrial "best practices" to the design and implementation of a novel sequence of undergraduate biomedical computing courses within the Department of Bio-medical Engineering at Marquette University (Milwaukee, Wisconsin). We have tightly integrated our industrial advisory board into this design and …