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Biomedical Engineering and Bioengineering Commons™

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2018

Biomedical Engineering Faculty Publications

Articles 1 - 9 of 9

Full-Text Articles in Biomedical Engineering and Bioengineering

Noncontact Speckle Contrast Diffuse Correlation Tomography Of Blood Flow Distributions In Tissues With Arbitrary Geometries, Siavash Mazdeyasna, Chong Huang, Mingjun Zhao, Nneamaka B. Agochukwu, Ahmed A. Bahrani, Lesley Wong, Guoqiang Yu Sep 2018

Noncontact Speckle Contrast Diffuse Correlation Tomography Of Blood Flow Distributions In Tissues With Arbitrary Geometries, Siavash Mazdeyasna, Chong Huang, Mingjun Zhao, Nneamaka B. Agochukwu, Ahmed A. Bahrani, Lesley Wong, Guoqiang Yu

Biomedical Engineering Faculty Publications

A noncontact electron multiplying charge-coupled-device (EMCCD)-based speckle contrast diffuse correlation tomography (scDCT) technology has been recently developed in our laboratory, allowing for noninvasive three-dimensional measurement of tissue blood flow distributions. One major remaining constraint in the scDCT is the assumption of a semi-infinite tissue volume with a flat surface, which affects the image reconstruction accuracy for tissues with irregular geometries. An advanced photometric stereo technique (PST) was integrated into the scDCT system to obtain the surface geometry in real time for image reconstruction. Computer simulations demonstrated that a priori knowledge of tissue surface geometry is crucial for precisely reconstructing the …

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Comparison Of Left Ventricular Strains And Torsion Derived From Feature Tracking And Dense Cmr, Gregory J. Wehner, Linyuan Jing, Christopher M. Haggerty, Jonathan D. Suever, Jing Chen, Sean M. Hamlet, Jared A. Feindt, Walter Dimitri Mojsejenko, Mark A. Fogel, Brandon K. Fornwalt Sep 2018

Comparison Of Left Ventricular Strains And Torsion Derived From Feature Tracking And Dense Cmr, Gregory J. Wehner, Linyuan Jing, Christopher M. Haggerty, Jonathan D. Suever, Jing Chen, Sean M. Hamlet, Jared A. Feindt, Walter Dimitri Mojsejenko, Mark A. Fogel, Brandon K. Fornwalt

Biomedical Engineering Faculty Publications

Background: Cardiovascular magnetic resonance (CMR) feature tracking is increasingly used to quantify cardiac mechanics from cine CMR imaging, although validation against reference standard techniques has been limited. Furthermore, studies have suggested that commonly-derived metrics, such as peak global strain (reported in 63% of feature tracking studies), can be quantified using contours from just two frames – end-diastole (ED) and end-systole (ES) – without requiring tracking software. We hypothesized that mechanics derived from feature tracking would not agree with those derived from a reference standard (displacement-encoding with stimulated echoes (DENSE) imaging), and that peak strain from feature tracking would agree with …

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Artificial Gravity As A Countermeasure To The Cardiovascular Deconditioning Of Spaceflight: Gender Perspectives, Joyce M. Evans, Charles F. Knapp, Nandu Goswami Jul 2018

Artificial Gravity As A Countermeasure To The Cardiovascular Deconditioning Of Spaceflight: Gender Perspectives, Joyce M. Evans, Charles F. Knapp, Nandu Goswami

Biomedical Engineering Faculty Publications

Space flight-induced physiological deconditioning resulting from decreased gravitational input, decreased plasma volume, and disruption of regulatory mechanisms is a significant problem in returning astronauts as well as in normal aging. Here we review effects of a promising countermeasure on cardiovascular systems of healthy men and women undergoing Earth-based models of space-flight. This countermeasure is produced by a centrifuge and called artificial gravity (AG). Numerous studies have determined that AG improves orthostatic tolerance (as assessed by various protocols) of healthy ambulatory men, of men deconditioned by bed rest or by immersion (both wet and dry) and, in one case, following spaceflight. …

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Elucidating The Mechanisms Of Two Unique Phenomena Governed By Particle-Particle Interaction Under Dep: Tumbling Motion Of Pearl Chains And Alignment Of Ellipsoidal Particles, Yu Zhao, Jozef Brcka, Jacques Faguet, Guigen Zhang Jun 2018

Elucidating The Mechanisms Of Two Unique Phenomena Governed By Particle-Particle Interaction Under Dep: Tumbling Motion Of Pearl Chains And Alignment Of Ellipsoidal Particles, Yu Zhao, Jozef Brcka, Jacques Faguet, Guigen Zhang

Biomedical Engineering Faculty Publications

Particle-particle interaction plays a crucial role in determining the movement and alignment of particles under dielectrophoresis (DEP). Previous research efforts focus on studying the mechanism governing the alignment of spherical particles with similar sizes in a static condition. Different approaches have been developed to simulate the alignment process of a given number of particles from several up to thousands depending on the applicability of the approaches. However, restricted by the simplification of electric field distribution and use of identical spherical particles, not much new understanding has been gained apart from the most common phenomenon of pearl chain formation. To enhance …

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Cortical Statistical Correlation Tomography Of Eeg Resting State Networks, Chuang Li, Han Yuan, Guofa Shou, Yoon-Hee Cha, Sridhar Sunderam, Walter Besio, Lei Ding May 2018

Cortical Statistical Correlation Tomography Of Eeg Resting State Networks, Chuang Li, Han Yuan, Guofa Shou, Yoon-Hee Cha, Sridhar Sunderam, Walter Besio, Lei Ding

Biomedical Engineering Faculty Publications

Resting state networks (RSNs) have been found in human brains during awake resting states. RSNs are composed of spatially distributed regions in which spontaneous activity fluctuations are temporally and dynamically correlated. A new computational framework for reconstructing RSNs with human EEG data has been developed in the present study. The proposed framework utilizes independent component analysis (ICA) on short-time Fourier transformed inverse source maps imaged from EEG data and statistical correlation analysis to generate cortical tomography of electrophysiological RSNs. The proposed framework was evaluated on three sets of resting-state EEG data obtained in the comparison of two conditions: (1) healthy …

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Walking Speed Differentially Alters Spinal Loads In Persons With Traumatic Lower Limb Amputation, Brad D. Hendershot, Iman Shojaei, Julian C. Acasio, Christopher L. Dearth, Babak Bazrgari Mar 2018

Walking Speed Differentially Alters Spinal Loads In Persons With Traumatic Lower Limb Amputation, Brad D. Hendershot, Iman Shojaei, Julian C. Acasio, Christopher L. Dearth, Babak Bazrgari

Biomedical Engineering Faculty Publications

Persons with lower limb amputation (LLA) perceive altered motions of the trunk/pelvis during activities of daily living as contributing factors for low back pain. When walking (at a singular speed), larger trunk motions among persons with vs. without LLA are associated with larger spinal loads; however, modulating walking speed is necessary in daily life and thus understanding the influences of walking speed on spinal loads in persons with LLA is of particular interest here. Three-dimensional trunk-pelvic kinematics, collected during level-ground walking at self-selected (SSW) and two controlled speeds (~1.0 and ~1.4 m/s), were obtained for seventy-eight participants: 26 with transfemoral …

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Mechanical Demands On The Lower Back In Patients With Non-Chronic Low Back Pain During A Symmetric Lowering And Lifting Task, Iman Shojaei, Elizabeth G. Salt, Quenten L. Hooker, Babak Bazrgari Mar 2018

Mechanical Demands On The Lower Back In Patients With Non-Chronic Low Back Pain During A Symmetric Lowering And Lifting Task, Iman Shojaei, Elizabeth G. Salt, Quenten L. Hooker, Babak Bazrgari

Biomedical Engineering Faculty Publications

There is limited information in the literature related to the lower back loading in patients with LBP, particularly those with non-chronic LBP. Toward addressing such a research gap, a case-control study was conducted to explore the differences in lower back mechanical loads between a group of females (n=19) with non-chronic, non-specific LBP and a group of asymptomatic females (n=19). The differences in lower back mechanical loads were determined when participants completed one symmetric lowering and lifting of a 4.5 kg load at their preferred cadence. The axial, shearing, and moment components of task demand at the time of peak moment …

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A Model-Based Approach For Estimation Of Changes In Lumbar Segmental Kinematics Associated With Alterations In Trunk Muscle Forces, Iman Shojaei, Navid Arjmand, Judith R. Meakin, Babak Bazrgari Mar 2018

A Model-Based Approach For Estimation Of Changes In Lumbar Segmental Kinematics Associated With Alterations In Trunk Muscle Forces, Iman Shojaei, Navid Arjmand, Judith R. Meakin, Babak Bazrgari

Biomedical Engineering Faculty Publications

The kinematics information from imaging, if combined with optimization-based biomechanical models, may provide a unique platform for personalized assessment of trunk muscle forces (TMFs). Such a method, however, is feasible only if differences in lumbar spine kinematics due to differences in TMFs can be captured by the current imaging techniques. A finite element model of the spine within an optimization procedure was used to estimate segmental kinematics of lumbar spine associated with five different sets of TMFs. Each set of TMFs was associated with a hypothetical trunk neuromuscular strategy that optimized one aspect of lower back biomechanics. For each set …

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Muscle Activity During Maximal Isometric Forearm Rotation Using A Power Grip, Joseph Scott Bader, Michael R. Boland, Desney Greybe, Arthur J. Nitz, Timothy L. Uhl, David A. Pienkowski Feb 2018

Muscle Activity During Maximal Isometric Forearm Rotation Using A Power Grip, Joseph Scott Bader, Michael R. Boland, Desney Greybe, Arthur J. Nitz, Timothy L. Uhl, David A. Pienkowski

Biomedical Engineering Faculty Publications

This study aimed to provide quantitative activation data for muscles of the forearm during pronation and supination while using a power grip. Electromyographic data was collected from 15 forearm muscles in 11 subjects while they performed maximal isometric pronating and supinating efforts in nine positions of forearm rotation. Biceps brachii was the only muscle with substantial activation in only one effort direction. It was significantly more active when supinating (µ = 52.1%, SD = 17.5%) than pronating (µ = 5.1%, SD = 4.8%, p < .001). All other muscles showed considerable muscle activity during both pronation and supination. Brachioradialis, flexor carpi radialis, palmaris longus, pronator quadratus and pronator teres were significantly more active when pronating the forearm. Abductor pollicis longus and biceps brachii were significantly more active when supinating. This data highlights the importance of including muscles additional to the primary forearm rotators in a biomechanical analysis of forearm rotation. Doing so will further our understanding of forearm function and lead to the improved treatment of forearm fractures, trauma-induced muscle dysfunction and joint replacements.

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