Engineering Commons^™

Corrosion Of Implant Materials In The Human Body, Maedeh Barzmehri

Corrosion Research

This paper extensively examines the complex problem of implant corrosion occurring within the human body. The corrosion of implants gives rise to substantial challenges, encompassing compromised implant durability, patient safety concerns, and potential adverse impacts on the long-term functionality of the medical device. The study's primary objectives include offering a concise overview of the various corrosion mechanisms that impact a range of implant materials and outlining health complications linked to the byproducts of implant corrosion. Furthermore, it delves into a cost analysis specific to hip or knee revision arthroplasty, which has become a prevalent scenario in implant failure cases on …

Using Machine Learning To Assist Auditory Processing Evaluation, Hasitha Wimalarathna, Sangamanatha Veeranna, Minh Vu Duong, Chris Allan Prof, Sumit K. Agrawal, Prudence Allen, Jagath Samarabandu, Hanif M. Ladak

Electrical and Computer Engineering Publications

Introduction: Approximately 0.2–5% of school-age children complain of listening difficulties in the absence of hearing loss. These children are often referred to an audiologist for an auditory processing disorder (APD) assessment. Adequate experience and training is necessary to arrive at an accurate diagnosis due to the heterogeneity of the disorder.

Objectives: The main goal of the study was to determine if machine learning (ML) can be used to analyze data from the APD clinical test battery to accurately categorize children with suspected APD into clinical sub-groups, similar to expert labels.

Methods: The study retrospectively collected data from 134 children referred …

Estimation Of Free Water-Corrected Microscopic Fractional Anisotropy., Nico J J Arezza, Tales Santini, Mohammad Omer, Corey A Baron

Medical Biophysics Publications

Water diffusion anisotropy MRI is sensitive to microstructural changes in the brain that are hallmarks of various neurological conditions. However, conventional metrics like fractional anisotropy are confounded by neuron fiber orientation dispersion, and the relatively low resolution of diffusion-weighted MRI gives rise to significant free water partial volume effects in many brain regions that are adjacent to cerebrospinal fluid. Microscopic fractional anisotropy is a recent metric that can report water diffusion anisotropy independent of neuron fiber orientation dispersion but is still susceptible to free water contamination. In this paper, we present a free water elimination (FWE) technique to estimate microscopic …

Rapid Microscopic Fractional Anisotropy Imaging Via An Optimized Linear Regression Formulation., N J J Arezza, D H Y Tse, C A Baron

Medical Biophysics Publications

Water diffusion anisotropy in the human brain is affected by disease, trauma, and development. Microscopic fractional anisotropy (μFA) is a diffusion MRI (dMRI) metric that can quantify water diffusion anisotropy independent of neuron fiber orientation dispersion. However, there are several different techniques to estimate μFA and few have demonstrated full brain imaging capabilities within clinically viable scan times and resolutions. Here, we present an optimized spherical tensor encoding (STE) technique to acquire μFA directly from the 2nd order cumulant expansion of the powder averaged dMRI signal obtained from direct linear regression (i.e. diffusion kurtosis) which requires fewer powder-averaged signals than …

Micro-Ct Of The Human Ossicular Chain: Statistical Shape Modeling And Implications For Otologic Surgery, Western University, London Health Sciences Centre

Electrical and Computer Engineering Publications

The ossicular chain is a middle ear structure consisting of the small incus, malleus and stapes bones, which transmit tympanic membrane vibrations caused by sound to the inner ear. Despite being shown to be highly variable in shape, there are very few morphological studies of the ossicles. The objective of this study was to use a large sample of cadaveric ossicles to create a set of three-dimensional models and study their statistical variance. Thirty-three cadaveric temporal bone samples were scanned using micro-computed tomography (μCT) and segmented. Statistical shape models (SSMs) were then made for each ossicle to demonstrate the divergence …

Intrinsic Measures And Shape Analysis Of The Intratemporal Facial Nerve, Thomas Hudson, Bradley Gare, Daniel Allen, Hanif Ladak, Sumit Agrawal

Electrical and Computer Engineering Publications

Hypothesis: To characterize anatomical measurements and shape variation of the facial nerve within the temporal bone, and to create statistical shape models (SSMs) to enhance knowledge of temporal bone anatomy and aid in automated segmentation.

Background: The facial nerve is a fundamental structure in otologic surgery, and detailed anatomic knowledge with surgical experience are needed to avoid its iatrogenic injury. Trainees can use simulators to practice surgical techniques, however manual segmentation required to develop simulations can be time consuming. Consequently, automated segmentation algorithms have been developed that use atlas registration, SSMs, and deep learning.

Methods: Forty cadaveric temporal bones were …

Hard, Soft And Off-The-Shelf Foot Orthoses And Their Effect On The Angle Of The Medial Longitudinal Arch: A Biplane Fluoroscopy Study, Megan E.R. Balsdon, Colin E. Dombroski, Kristen Bushey, Thomas Jenkyn

Mechanical and Materials Engineering Publications

Background: Foot orthoses have proven to be effective for conservative management of various pathologies. Pathologies of the lower limb can be caused by abnormal biomechanics such as abnormal foot structure and alignment, leading to inadequate support. Objectives: To compare biomechanical effects of different foot orthoses on the medial longitudinal arch (MLA) during dynamic gait using skeletal kinematics. Study Design: Prospective, cross-sectional study design. Methods: The MLA angle was measured for 12 participants among three groups: pes planus, pes cavus and normal arch. Five conditions were compared: three orthotic devices (hard custom foot orthosis (CFO), soft CFO, and off-the-shelf Barefoot Science©), …

Dynamic Light Scattering Optical Coherence Tomography To Probe Motion Of Subcellular Scatterers., Nico J J Arezza, Marjan Razani, Michael C Kolios

Medical Biophysics Publications

Optical coherence tomography (OCT) is used to provide anatomical information of biological systems but can also provide functional information by characterizing the motion of intracellular structures. Dynamic light scattering OCT was performed on intact, control MCF-7 breast cancer cells and cells either treated with paclitaxel to induce apoptosis or deprived of nutrients to induce oncosis. Autocorrelations (ACs) of the temporal fluctuations of OCT intensity signals demonstrate a significant decrease in decorrelation time after 24 h in both the paclitaxel-treated and nutrient-deprived cell groups but no significant differences between the two groups. The acquired ACs were then used as input for …

Resting State Functional Network Disruptions In A Kainic Acid Model Of Temporal Lobe Epilepsy., Ravnoor Singh Gill, Seyed M Mirsattari, L Stan Leung

Physiology and Pharmacology Publications

We studied the graph topological properties of brain networks derived from resting-state functional magnetic resonance imaging in a kainic acid induced model of temporal lobe epilepsy (TLE) in rats. Functional connectivity was determined by temporal correlation of the resting-state Blood Oxygen Level Dependent (BOLD) signals between two brain regions during 1.5% and 2% isoflurane, and analyzed as networks in epileptic and control rats. Graph theoretical analysis revealed a significant increase in functional connectivity between brain areas in epileptic than control rats, and the connected brain areas could be categorized as a limbic network and a default mode network (DMN). The …

An Intra-Bone Axial Load Transducer: Development And Validation In An In-Vitro Radius Model, Nikolas K. Knowles, Michael Gladwell, Louis M. Ferreira

Surgery Publications

Background

Accurate measurement of forces through the proximal radius can assess the effects of some surgical procedures on radioulnar load sharing, but is difficult to achieve given the redundant loading nature of the musculoskeletal system. Previously reported devices have relied on indirect measurements that may alter articular joint location and function. An axial load transducer interposed in the diaphysis of the radius may accurately quantify unknown axial loads of the proximal radius, and maintain articular location.

Methods

An in-vitro radius model was developed by interposing an axial load transducer in the diaphysis of the proximal radius. Static loads of 20, …

Resting-State Connectivity Identifies Distinct Functional Networks In Macaque Cingulate Cortex., R Matthew Hutchison, Thilo Womelsdorf, Joseph S Gati, L Stan Leung, Ravi S Menon, Stefan Everling

Physiology and Pharmacology Publications

Subregions of the cingulate cortex represent prominent intersections in the structural networks of the primate brain. The relevance of the cingulate to the structure and dynamics of large-scale networks ultimately requires a link to functional connectivity. Here, we map fine-grained functional connectivity across the complete extent of the macaque (Macaca fascicularis) cingulate cortex and delineate subdivisions pertaining to distinct identifiable networks. In particular, we identified 4 primary networks representing the functional spectrum of the cingulate: somatomotor, attention-orienting, executive, and limbic. The cingulate nodes of these networks originated from separable subfields along the rostral-to-caudal axis and were characterized by positive and …

A Comparison Of Two Headless Compression Screws For Operative Treatment Of Scaphoid Fractures, Ruby Grewal, Joseph Assini, David Sauder, Louis Ferreira, Jim Johnson, Kenneth Faber

Surgery Publications

PURPOSE: The purpose of this study was to compare the interfragmentary compression force across a simulated scaphoid fracture by two commonly used compression screw systems; the Acutrak 2 Standard and the 3.0 mm Synthes headless compression screw.

METHODS: Sixteen (8 pairs; 6 female, 2 male) cadaver scaphoids were randomly assigned to receive either the Acutrak 2 or Synthes screw with the contralateral scaphoid designated to receive the opposite. Guide wires were inserted under fluoroscopic control. Following transverse osteotomy, the distal and proximal fragments were placed on either side of a custom load cell, to measure interfragmentary compression. Screws were placed …

Use Of Imaging Biomarkers To Assess Perfusion And Glucose Metabolism In The Skeletal Muscle Of Dystrophic Mice, Nabeel Ahmad, Ian Welch, Robert Grange, Jennifer Hadway, Savita Dhanvantari, David Hill, Ting-Yim Lee, Lisa M Hoffman

Robarts Imaging Publications

BACKGROUND: Duchenne muscular dystrophy (DMD) is a severe neuromuscular disease that affects 1 in 3500 boys. The disease is characterized by progressive muscle degeneration that results from mutations in or loss of the cytoskeletal protein, dystrophin, from the glycoprotein membrane complex, thus increasing the susceptibility of contractile muscle to injury. To date, disease progression is typically assessed using invasive techniques such as muscle biopsies, and while there are recent reports of the use of magnetic resonance, ultrasound and optical imaging technologies to address the issue of disease progression and monitoring therapeutic intervention in dystrophic mice, our study aims to validate …

The Yin And Yang Actions Of North American Ginseng Root In Modulating The Immune Function Of Macrophages, Chike Godwin Azike, Paul Abrahams Charpentier, Jirui Hou, Hua Pei, Edmund Man King Lui

Physiology and Pharmacology Publications

BACKGROUND: Immuno-modulatory effects of ginseng, including both immuno-stimulatory and immuno-suppressive effects, have been widely reported. This study aims to determine whether the paradoxical immuno-modulatory effect is related to unique phytochemical profiles of different North American (NA) ginseng, namely aqueous (AQ) and alcoholic (ALC) extracts.

METHODS: AQ and ALC extracts were prepared and their immuno-bioactivity were studied in vitro in murine macrophages (Raw 264.7) through measuring the direct stimulatory production of pro-inflammatory mediator and cytokines as well as the suppression of lipopolysaccharide (LPS)-stimulatory response by the two extracts. Gel permeation chromatography was used to fractionate and isolate phytochemicals for characterization of …

A Review Of Autoimmune Diseases Associated With Cancer, Patricia Tai, Edward Yu, Kurian Joseph, Thomas Miale

Oncology Publications

The focus of this review is on the relationships between autoimmune diseases and cancer from two closely related perspectives: 1.Those autoimmune diseases which are often associated with malignancies. 2.Those prevalent cancers which may increase the risks of developing autoimmune disorders. The review concludes with a brief discussion of some selected innovative approaches to cancer immunotherapy.

Robot Assisted Ultrasound Imaged Guided Interstitial Lung Brachytherapy In A Porcine Model, Richard A. Malthaner, Edward Yu, Jerry J. Battista, Chris Blake, Donal Downey, Aaron Fenster

Oncology Presentations

We set out to see if permanent interstitial brachytherapy seeds could be safely and reproducibly inserted thoracoscopicaly with the ZEUS Robotic system and intraoperative ultrasound into in-vivo porcine lungs.

Evaluation Of Intra-And Inter-Fraction Motion In Breast Radiotherapy Using Electronic Portal Imaging Cine Loops, Chrison Lee, Edward Yu, Tomas Kron

Oncology Presentations

Parallel tangent breast irradiation is commonly used postbreast conservation surgery for early breast cancer patient without lymph node involvement to improve local disease control. Intra-fractional and inter-fractional variabilities are often presented in daily treatment setup. The present pilot study used Electronic Portal Imaging (EPI) to evaluate intra-and inter-fraction motion in patients undergoing simple breast tangent radiotherapy.

Is Extended Volume Of External Beam Irradiation Beneficial In Post-Esophagectomy High Risk Patients Receiving Combined Chemoradiation Therapy?, E. Yu, A. R. Dar, R. Ash, G. Videtic, P. Truong, L. Stitt, A. Tomiak, M. Vincent, R. Malthaner, I. Craig, E. Brecevic, W. Kocha, R. Inculet, M. Lefcoe

Oncology Presentations

OBJECTIVE: To assess the value of extended volume irradiation with anastomotic coverage in high risk resected esophageal cancer patients.

METHOD: A retrospective study was undertaken at LRCC from 1989-1999 for high risk resected esophageal cancer patients. Adjuvant treatments consisted of 4 cycles of chemotherapy (epirubicin/fluorouracil/cisplatin or cisplatin/fluorouracil), and local regional irradiation with or without coverage of the anastomotic site. Radiation dose ranged from 45-60Gy at 1.8-2.0 Gy/fraction given with initial anterior-posterior/posterior-anterior arrangement with either extended (with anastomotic coverage) or small (without anastomotic coverage) field followed by oblique fields for boost.

RESULT: One hundred eighty-eight charts were reviewed. Seventy-two patients were …