Biomedical Engineering and Bioengineering Commons^™

Light Scattering Measured With Spatial Frequency Domain Imaging Can Predict Stromal Versus Epithelial Proportions In Surgically Resected Breast Tissue, David M. Mcclatchy, Elizabeth J. Rizzo, Wendy A. Wells, Candice C. Black, Keith D. Paulsen, Stephen C. Kanick, Brian W. Pogue

Dartmouth Scholarship

This study aims to determine if light scatter parameters measured with spatial frequency domain imaging (SFDI) can accurately predict stromal, epithelial, and adipose fractions in freshly resected, unstained human breast specimens. An explicit model was developed to predict stromal, epithelial, and adipose fractions as a function of light scattering parameters, which was validated against a quantitative analysis of digitized histology slides for N  =  31 specimens using leave-one-out cross-fold validation. Specimen mean stromal, epithelial, and adipose volume fractions predicted from light scattering parameters strongly correlated with those calculated from digitized histology slides (r  =  0.90, 0.77, and 0.91, respectively, p-value× …

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 …

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 …

Quantifying Cancer Cell Receptors With Paired-Agent Fluorescent Imaging: A Novel Method To Account For Tissue Optical Property Effects., Negar Sadeghipour, Scott C. Davis, Kenneth M. Tichauer

Dartmouth Scholarship

Dynamic fluorescence imaging approaches can be used to estimate the concentration of cell surface receptorsin vivo. Kinetic models are used to generate the final estimation by taking the targeted imaging agent concentration as a function of time. However, tissue absorption and scattering properties cause the final readout signal to be on a different scale than the real fluorescent agent concentration. In paired-agent imaging approaches, simultaneous injection of a suitable control imaging agent with a targeted one can account for non-specific uptake and retention of the targeted agent. Additionally, the signal from the control agent can be a normalizing …

Using Electromyography Of Five Muscles And Joint Angle To Predict Knee Joint Moment, Mohamadreza Karimi Bokti, Alireza Hashemi Oskouei

Conference Presentations

Forces and moments acting on joints is of great importance in different fields of biomechanics such as ergonomics, sports biomechanics, and rehabilitation. EMG driven models can be used to estimate forces and moments acting on joints. The current study aimed to propose a model for prediction of knee joint moment using EMG signals detected from muscles and knee joint angle. Electromyography of knee muscles, knee joint angle and moment were recorded simultaneously during the extension-flexion movement in three young men using an isokinetic system. The model for estimating knee joint moment was developed using multiple linear regression. In order to …

In Vivo Brainstem Imaging In Alzheimer’S Disease: Potential For Biomarker Development, David J. Braun, Linda J. Van Eldik

Neuroscience Faculty Publications

The dearth of effective treatments for Alzheimer’s disease (AD) is one of the largest public health issues worldwide, costing hundreds of billions of dollars per year. From a therapeutic standpoint, research efforts to date have met with strikingly little clinical success. One major issue is that trials begin after substantial pathological change has occurred, and it is increasingly clear that the most effective treatment regimens will need to be administered earlier in the disease process. In order to identify individuals within the long preclinical phase of AD who are likely to progress to dementia, improvements are required in biomarker development. …

Hydrodeoxygenation Of Aqueous Phase Catalytic Pyrolysis Oil To Liquid Hydrocarbons Using Multi-Functional Nickel Catalyst, Hossein Jahromi, Foster A. Agblevor

Biological Engineering Faculty Publications

Herein we investigated the hydrodeoxygenation (HDO) of aqueous phase pinyon-juniper catalytic pyrolysis oil (APPJCPO) using a new multifunctional red mud-supported nickel (Ni/RM) catalyst. The organic liquid yield after HDO of APPJCPO using 30 wt. % Ni/RM at reaction temperature of 350 °C was 47.8 wt. % with oxygen content of 1.14 wt. %. The organic liquid fraction consisted of aliphatics, aromatics, and alkylated aromatic hydrocarbons as well as small amounts of oxygenates. The RM support catalyzed ketonization of carboxylic acids. The Ni metal catalyzed partial reduction of oxygenates that underwent carbonyl alkylation with aldehydes and ketones on the RM. Catalyst …

Synthesis And Characterization Of Controlled Nitric Oxide Release From S-Nitroso-N-Acetyl-D-Penicillamine Covalently Linked To Polyvinyl Chloride (Snap-Pvc), Sean Hopkins, Megan C. Frost

Michigan Tech Publications, Part 1

Polyvinyl chloride (PVC) is one of the most widely used polymers in medicine but has very poor biocompatibility when in contact with tissue or blood. To increase biocompatibility, controlled release of nitric oxide (NO) can be utilized to mitigate and reduce the inflammatory response. A synthetic route is described where PVC is aminated to a specified degree and then further modified by covalently linking S-nitroso-N-acetyl-d-penicillamine (SNAP) groups to the free primary amine sites to create a nitric oxide releasing polymer (SNAP-PVC). Controllable release of NO from SNAP-PVC is described using photoinitiation from light emitting diodes (LEDs). Ion-mediated NO release is …

An Efficient Process For Co-Production Of Γ-Aminobutyric Acid And Probiotic Bacillus Subtilis Cells, Hongbo Wang, Jinge Huang, Lei Sun, Fuchao Xu, Wei Zhang, Jixun Zhan

Biological Engineering Faculty Publications

This study was to establish an integrated process for the co-production of γ-aminobutyric acid (GABA) and live probiotics. Six probiotic bacteria were screened and Bacillus subtilis ATCC 6051 showed the highest GABA-producing capacity. The optimal temperature and initial pH value for GABA production in B. subtilis were found to be 30 °C and 8.0, respectively. A variety of carbon and nitrogen sources were tested, and potato starch and peptone were the preferred carbon and nitrogen sources for GABA production, respectively. The concentrations of carbon source, nitrogen source and substrate (sodium L-glutamate) were then optimized using the response surface methodology. The …

Wave Energy Converter Array Optimization: A Genetic Algorithm Approach And Minimum Separation Distance Study, Chris Sharp, Bryony Dupont

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

With the need to integrate renewable energy sources into the current energy portfolio and the proximity of power consumers to ocean coastlines, it is important to evaluate marine energy systems, specifically wave energy converters (WECs), as potential solutions for meeting electricity needs. The ability to model these systems computationally is vital to their eventual deployment. The power development, economics, grid integration requirements, operations and maintenance requirements, and ecological impacts must be understood before these devices are physically installed. However, the research area of WEC array optimization is young, and the few available results of previously implemented optimization methods are preliminary. …

Nonprehensile Manipulation Of Deformable Objects: Achievements And Perspectives From The Rodyman Project, Aykut C. Satici

Mechanical and Biomedical Engineering Faculty Publications and Presentations

The goal of this work is to disseminate the results achieved so far within the RODYMAN project related to planning and control strategies for robotic nonprehensile manipulation. The project aims at advancing the state of the art of nonprehensile dynamic manipulation of rigid and deformable objects to future enhance the possibility of employing robots in anthropic environments. The final demonstrator of the RODYMAN project will be an autonomous pizza maker. This article is a milestone to highlight the lessons learned so far and pave the way towards future research directions and critical discussions.

Determining The Respiratory State From A Seismocardiographic Signal - A Machine Learning Approach, Christian Ulrich, Martin Jensen, Rolf Oberlin, Kouhyar Tavakolian, Farzad Khosrow-Khavar, Andrew Blaber, Kasper Sørensen, Samuel Schmidt

Electrical Engineering Faculty Publications

Seismocardiography (SCG) is a non-invasive method for measurement of vibrations on the chest wall originating from the heart. Respiration changes the morphology of the SCG-signal and analyzing these changes could improve the diagnostic value of SCG. This study aimed to determine the nasal respiration signal amplitude at mitral closure (MC) and aortic opening (AO) using SCG features. The three proposed methods for this were multiple regression analysis (MRA), support vector regression (SVR), and a neural network (NN). SCG, Electrocardiography and nasal-catheter flow signals were acquired from 18 healthy subjects (age 29± 6). SCG-signal fiducial points were used as features and …

Deformation Of A Ferrofluid Droplet In Simple Shear Flows Under Uniform Magnetic Fields, Md Rifat Hassan, Jie Zhang, Cheng Wang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We numerically investigate the deformation and orientation of a ferrofluid droplet in a simple shear flow under a uniform magnetic field. The numerical simulation is based on the finite element method and couples the magnetic and flow fields. A level set method is used to model the dynamic motion of the droplet interface. Systematic numerical simulations are used to assess the effects of the direction and the strength of the magnetic field. Focusing on low Reynolds number flows (Re ≲ 0.02), the numerical results indicate that at a small capillary number (Ca ≈ 0.02), the magnetic field dominates over the …

Voltage Effects On Muscarinic Acetylcholine Receptor-Mediated Contractions Of Airway Smooth Muscle, Iurii Semenov, Robert Brenner

Bioelectrics Publications

Studies have shown that the activity of muscarinic receptors and their affinity to agonists are sensitive to membrane potential. It was reported that in airway smooth muscle (ASM) depolarization evoked by high K⁺ solution increases contractility through direct effects on M3 muscarinic receptors. In this study, we assessed the physiological relevance of voltage sensitivity of muscarinic receptors on ASM contractility. Our findings reveal that depolarization by high K⁺ solution induces contraction in intact mouse trachea predominantly through activation of acetylcholine release from embedded nerves, and to a lesser extent by direct effects on M3 receptors. We therefore devised …

Moderate Heat Application Enhances The Efficacy Of Nanosecond Pulse Stimulation For The Treatment Of Squamous Cell Carcinoma, Chelsea M. Edelblute, Sigi Guo, Embo Yang, Chunqi Jiang, Karl Schoenbach, Richard Heller

Bioelectrics Publications

Nanosecond pulse stimulation as a tumor ablation therapy has been studied for the treatment of various carcinomas in animal models and has shown a significant survival benefit. In the current study, we found that moderate heating at 43°C for 2 minutes significantly enhanced in vitro nanosecond pulse stimulation-induced cell death of KLN205 murine squamous cell carcinoma cells by 2.43-fold at 600 V and by 2.32-fold at 900 V, as evidenced by propidium iodide uptake. Furthermore, the ablation zone in KLN205 cells placed in a 3-dimensional cell-culture model and pulsed at a voltage of 900 V at 43°C was 3 times …

Microfluidic Electrical Impedance Spectroscopy, John J. Foley

Master's Theses

The goal of this study is to design and manufacture a microfluidic device capable of measuring changes in impedance valuesof microfluidic cell cultures. Tocharacterize this, an interdigitated array of electrodes was patterned over glass, where it was then bonded to a series of fluidic networks created in PDMS via soft lithography. The device measured ethanol impedance initially to show that values remain consistent over time. Impedance values of water and 1% wt. saltwater were compared to show that the device is able to detect changes in impedance, with up to a 60% reduction in electrical impedance in saltwater. Cells were …

Early Term Effects Of Rhbmp-2 On Pedicle Screw Fixation In A Sheep Model: Histomorphometric And Biomechanical Analyses, Jeffrey M. Toth, Mei Wang, Chetan Patel, Akshi Arora

Biomedical Engineering Faculty Research and Publications

Background: The effects of recombinant human bone morphogenetic protein-2 (rhBMP-2) on pedicle screw pullout force and its potential to improve spinal fixation have not previously been investigated. rhBMP-2 on an absorbable collagen sponge (ACS) carrier was delivered in and around cannulated and fenestrated pedicle screws in a sheep lumbar spine instability model. Two control groups (empty screw and ACS with buffer) were also evaluated. We hypothesized that rhBMP-2 could stimulate bone growth in and around the cannulated and fenestrated pedicle screws to improve early bone purchase.

Methods: Eight skeletally mature sheep underwent destabilizing laminectomies at L2–L3 and L4–L5 followed by …

In Vitro Growth Of Osteoblasts On Poly Lactic-Co-Glycolic Acid Scaffolds Created Via Gas Foaming, Matthew James Thomas

Master's Theses

This study analyzed the feasibility of using gas foaming to create Poly Lactic-co-Glycolic Acid (PLGA) scaffolds for use as a substrate in bone tissue engineering and set out to determine whether the presence of osteoblasts on these scaffolds enhanced their material stiffness. The process of bone formation involves osteoblasts depositing extracellular matrix and calcifying this matrix with calcium phosphate crystals (Hasegawa et al., 2017) and pits between 30-40μm in diameter on tissue engineering scaffold surfaces have been shown to best promote osteogenic activity in the presence of bone-forming cells (Halai et al., 2014).The scaffolds were determined to contain pits within …

Technical Note: Enhancing Soft Tissue Contrast And Radiation‐Induced Image Changes With Dual‐Energy Ct For Radiation Therapy, George Noid, An Tai, Diane Schott, Nilesh Mistry, Yu Liu, Taly Gilat Schmidt, Jared R. Robbins, X. Allen Li

Biomedical Engineering Faculty Research and Publications

Purpose

The purpose of this work is to investigate the use of low‐energy monoenergetic decompositions obtained from dual‐energy CT (DECT) to enhance image contrast and the detection of radiation‐induced changes of CT textures in pancreatic cancer.

Methods

The DECT data acquired for 10 consecutive pancreatic cancer patients during routine nongated CT‐guided radiation therapy (RT) using an in‐room CT (Definition AS Open, Siemens Healthcare, Malvern, PA) were analyzed. With a sequential DE protocol, the scanner rapidly performs two helical acquisitions, the first at a tube voltage of 80 kVp and the second at a tube voltage of 140 kVp. Virtual monoenergetic …

Temporal And Spatial Effects Of Shock Overpressure On Blood-Brain Barrier Permeability In Blast-Induced Traumatic Brain Injury, Matthew Joseph Kuriakose

Dissertations

Exposure to shock waves is the leading cause of traumatic brain injury (TBI) in military personnel and blast-induced TBI (bTBI) is considered the signature wound in recent conflicts in Iraq and Afghanistan. Many researchers attempt to replicate field-relevant shock waves in laboratory settings through the use of gas-driven shock tubes in order to investigate the generation and propagation of shock waves and also explore possible mechanisms of bTBI. Among several injury mechanisms of bTBI, damage to the blood-brain barrier (BBB) has been identified as a potential candidate and has been the focus of several clinical and experimental investigations aimed to …