Biomedical Engineering and Bioengineering Commons^™

On The Application Of Mechanical Vibration In Robotics-Assisted Soft Tissue Intervention, Iman Khalaji

Electronic Thesis and Dissertation Repository

Mechanical vibration as a way of transmitting energy has been an interesting subject to study. While cyclic oscillation is usually associated with fatigue effect, and hence a detrimental factor in failure of structures and machineries, by controlled transmission of vibration, energy can be transferred from the source to the target. In this thesis, the application of such mechanical vibration in a few surgical procedures is demonstrated.

Three challenges associated with lung cancer diagnosis and treatment are chosen for this purpose, namely, Motion Compensation, tumor targeting in lung Needle Insertion and Soft Tissue Dissection:

1. A robotic solution is proposed …

A New Generation Of Polymer/Ceramic Composite Biomaterials For Bone Regeneration, Mehrnaz Salarian

Electronic Thesis and Dissertation Repository

There is a substantial emerging interest for fundamental and applied research on the reinforcement of polymeric materials using nanotechnology. In the biomedical industry, development of novel bone cement composite materials with enhanced mechanical properties is of tremendous potential importance. The most universally used injectable bone cement is made of poly(methyl methacrylate) (PMMA); however, the major disadvantage of PMMA is its non-biodegradability. Polymers such as poly(propylene fumarate) (PPF) and polycaprolactone (PCL) are biodegradable, but suffer from a lack of mechanical properties. The aim of this research was to test the efficacy of these biodegradable polymers integrating nanotechnology for the development of …

Poly(Ester Amide) And Poly(Ethyl Glyoxylate) Nanoparticles For Controlled Drug Release, Amira Mohamed Moustafa

Electronic Thesis and Dissertation Repository

The objective of this research was to develop polymeric nanoparticles (NPs) having improved drug release properties for drug delivery. Poly(ester amide)s (PEAs) are promising biodegradable polymers. PEA NPs were prepared via emulsification-evaporation and salting-out methods and optimized through by varying different processing parameters. Polymer-model drug conjugates based on PEAs containing L-aspartic acid and rhodamine B were synthesized and used for NP preparation. Release behavior was studied and compared to a control system with physically encapsulated rhodamine B. It was shown that the release of rhodamine B from the covalent system did not show the burst effect and exhibited a slower …

Digestion Of Municipal Wastewater Biosolids Using An Anaerobic Fluidized Bed Bioreactor (Anfbr), Zhenqi Wang

Electronic Thesis and Dissertation Repository

This research investigated the efficacy of the anaerobic fluidized bed bioreactor (AnFBR) technology in treating municipal wastewater sludges. Primary sludge (PS) and thickened waste activated sludge (TWAS) were studied in two lab-scale AnFBRs using High-density polyethylene (HDPE) as carrier media. PS was investigated at various organic loading rates (OLRs) ranging from 9 to 18 kg chemical oxygen demand (COD)/m³-d corresponding to hydraulic retention times (HRTs) of 2 to 4 days, with maximum COD and volatile suspended solid (VSS) removal efficiency of 70% and 72%, respectively. For TWAS, VSS destruction efficiency varied from 53% at an HRT of 4 …

Design Of A Haptic Interface For Medical Applications Using Magneto-Rheological Fluid Based Actuators, Nima Najmaei

Electronic Thesis and Dissertation Repository

This thesis reports on the design, construction, and evaluation of a prototype two degrees-of-freedom (DOF) haptic interface, which takes advantage of Magneto-Rheological Fluid (MRF) based clutches for actuation. Haptic information provides important cues in teleoperated systems and enables the user to feel the interaction with a remote or virtual environment during teleoperation. The two main objectives in designing a haptic interface are stability and transparency. Indeed, deficiencies in these factors in haptics-enabled telerobotic systems has the introduction of haptics in medical environments where safety and reliability are prime considerations. An actuator with poor dynamics, high inertia, large size, and heavy …

Ultrasound-Guided Mechatronic System For Targeted Delivery Of Cell-Based Cancer Vaccine Immunotherapy In Preclinical Models, Adem Nadjib Hadj Boussaad

Electronic Thesis and Dissertation Repository

Injection of dendritic cell (DC) vaccines into lymph nodes (LN) is a promising strategy for eliciting immune responses against cancer, but these injections in mouse cancer models are challenging due to the small target scale (~ 1 mm × 2 mm). Direct manual intranodal injection is difficult and can cause architectural damage to the LN, potentially disrupting crucial interactions between DC and T cells. Therefore, a second-generation ultrasound-guided mechatronic device has been developed to perform this intervention. A targeting accuracy of < 500 μm will enable targeted delivery of the DCs specifically to a LN subcapsular space. The device was redesigned from its original CT-guided edition, which used a remote centre of motion architecture, to be easily integrated onto a commercially available VisualSonics imaging rail system. Subtle modifications were made to ensure simple workflow that allows for live-animal interventions that fall within the knockout periods stated in study protocols. Several calibration and registration techniques were developed in order to achieve an overall targeting accuracy appropriate for the intended application. A variety of methods to quantify the positioning accuracy of the device were investigated. The method chosen involved validating a guided injection into a tissue-mimicking phantom using ultrasound imaging post-operatively to localize the end-point position of the needle tip in the track left behind by the needle. Ultrasound-guided injections into a tissue-mimicking phantom revealed a targeting accuracy of 285 ± 94 μm for the developed robot compared to 508 ± 166 μm for a commercial-available manually-actuated injection device from VisuailSonics. The utility of the robot was also demonstrated by performing in vivo injections into the lymph nodes of mice.

The Effect Of Fixation Plate Length On Spinal Instability Following Anterior Cervical Plate Fixation For The Repair Of In Vitro Flexion-Distraction Injuries, Abdulaziz J. Al-Kuwari

Electronic Thesis and Dissertation Repository

Abstract:

The Effect of Fixation Plate Length on Spinal Instability Following Anterior Cervical Plate Fixation for the Repair of in Vitro Flexion-Distraction Injuries

Introduction: Anterior cervical decompression and fusion with a plate (ACDFP) is a commonly performed treatment following a traumatic injury to the subaxial cervical spine. The purpose of the presented work was to determine the biomechanical effect of plate length on cervical spine kinematic stability following ACDFP stabilization for a simulated traumatic injury.

Methods: Eleven fresh-frozen cadaveric C5-C6 and C6-C7 motion segments were examined in this study. To assess kinematics, flexibility testing was performed on each specimen …

Characterization Of A Contact-Stylus Surface Digitization Method Using Collaborative Robots: Accuracy Evaluation In The Context Of Shoulder Replacement Or Resurfacing, Sara Saud Zimmo

Electronic Thesis and Dissertation Repository

Total shoulder arthroplasty (TSA) is the third most common joint replacement. While robot-assisted hip and knee replacement technologies have enjoyed extensive development, this has been limited in the upper limb. This work focused on quantifying the localization accuracy of a robotic system, and evaluating its efficacy in the context of TSA.

A collaborative robot was fitted with a stylus tip to perform manual surface digitizations using the robot’s encoder output. In the first experiment, two precision-machined master cubes, representing the working volume around a glenoid structure, were used for system validation. Next, cadaveric glenoids were digitized and compared to a …

Dynamic Image Processing For Guidance Of Off-Pump Beating Heart Mitral Valve Repair, Feng Li

Electronic Thesis and Dissertation Repository

Compared to conventional open heart procedures, minimally invasive off-pump beating heart mitral valve repair aims to deliver equivalent treatment for mitral regurgitation with reduced trauma and side effects. However, minimally invasive approaches are often limited by the lack of a direct view to surgical targets and/or tools, a challenge that is compounded by potential movement of the target during the cardiac cycle. For this reason, sophisticated image guidance systems are required in achieving procedural efficiency and therapeutic success. The development of such guidance systems is associated with many challenges. For example, the system should be able to provide high quality …

Finite Element Modeling Of The Proximal Humerus To Compare Stemless, Short And Standard Stem Humeral Components Of Varying Material Stiffness For Shoulder Arthroplasty, Najmeh Razfar

Electronic Thesis and Dissertation Repository

In patients with debilitating pain due to osteoarthritis, total shoulder arthroplasty can restore function and provide effective pain relief. Newer implant designs vary in length and material stiffness. Unfortunately, literature on these newer implants is limited. This thesis investigates the effect of stem length and implant material stiffness on proximal humeral bone stresses. 3D bone models with implants of various stem lengths (stemless, short, and standard) and different material stiffness’s (CoCr, Ti and PEEK) were generated using MIMICS, Solidworks and ABAQUS for varying abduction angles (15°, 45° and 75°). Cortical and trabecular stresses were contrasted with the intact bone state. …

Visual Perception And Cognition In Image-Guided Intervention, Kamyar Abhari

Electronic Thesis and Dissertation Repository

Surgical image visualization and interaction systems can dramatically affect the efficacy and efficiency of surgical training, planning, and interventions. This is even more profound in the case of minimally-invasive surgery where restricted access to the operative field in conjunction with limited field of view necessitate a visualization medium to provide patient-specific information at any given moment. Unfortunately, little research has been devoted to studying human factors associated with medical image displays and the need for a robust, intuitive visualization and interaction interfaces has remained largely unfulfilled to this day. Failure to engineer efficient medical solutions and design intuitive visualization interfaces …

Prostate Tumor Volume Measurement On Digital Histopathology And Magnetic Resonance Imaging, Mehrnoush Salarian

Electronic Thesis and Dissertation Repository

An accurate assessment of prostate tumour burden supports appropriate treatment selection, ranging from active surveillance through focal therapy, to radical whole-prostate therapies. For selected patients, knowledge of the three-dimensional locations and sizes of prostate tumours on pre-procedural imaging supports planning of effective focal therapies that preferentially target tumours, while sparing surrounding healthy tissue. In the post-prostatectomy context, pathologic measurement of tumour burden in the surgical specimen may be an independent prognostic factor determining the need for potentially life-saving adjuvant therapy. An accurate and repeatable method for tumour volume assessment based on histology sections taken from the surgical specimen would be …

Advances In Image Acquisition And Filtering For Mri Neuroimaging At 7 Tesla, Andrew T. Curtis

Electronic Thesis and Dissertation Repository

Performing magnetic resonance imaging at high magnetic field strength promises many improvements over low fields that are of direct benefit in functional neuroimaging. This includes the possibility of improved signal-to-noise levels, and increased BOLD functional contrast and spatial specificity. However, human MRI at 7T and above suffers from unique engineering challenges that limit the achievable gains. In this thesis, three technological developments are introduced, all of which address separate issues associated with functional magnetic resonance neuroimaging at very high magnetic field strengths.

First, the image homogeneity problem is addressed by investigating methods of RF shimming — modifying the excitation portion …

Characterization And Assessment Of Mechanical Properties Of Adipose Derived Breast Tissue Scaffolds As A Means For Breast Reconstructive Purposes, Ehsan Omidi

Electronic Thesis and Dissertation Repository

Decellularized adipose tissue (DAT) has shown great potential for use as a regenerative scaffold in breast reconstruction following mastectomies or lumpectomies. Mechanical properties of such scaffolds are of great importance in order to mimic natural adipose tissue. This study focuses on the characterization of mechanical properties and assessment of DAT scaffolds for implantation into a human breast. DAT samples sourced from multiple adipose tissue depots within the body were tested and their elastic and hyperelastic parameters were obtained. Subsequently simulations were conducted where the calculated hyperelastic parameters were tested as a real human breast model under two different gravity loading …

Design And Assessment Of An Experimental Test Setup For Use In Studies On The Vibrational Response Of The Head To Impact, Claudia M. Blandford

Electronic Thesis and Dissertation Repository

With the mortality, disability and socioeconomic costs associated with head injury, head impact biomechanics is important to developing injury criterions and safety tolerances. However, the current state of knowledge is contradictory and vague. This thesis will contribute to research done on the vibrational response of the head to impact by discussing two studies. The first will describe the design, implementation and validation of a head impactor setup specific for the study of the frequency response of the skull. An impactor capable of producing sub-5ms duration, sub-fracture impacts was successfully designed. The apparatus was validated by comparing the results of a …

Laser-Assisted Surface Modification Of Hybrid Hydrogels To Prevent Bacterial Contamination And Protein Fouling, Guobang Huang

Electronic Thesis and Dissertation Repository

Silicone hydrogels have been extensively studied in the fields of contact lenses, tissue engineering, and drug delivery due to their good biocompatibility, high oxygen permeability, and proper light transmission. However, their applications in biomedical devices are limited by protein adsorption and bacterial contamination because of the hydrophobic surface of silicone, which will cause more irreversible protein adsorption. Several physical methods can be applied to create a hydrophilic surface on hydrogels, such as spin coating, physical vapor deposition, dip coating, drop casting, etc. Compared to the conventional methods, the matrix assisted pulsed laser evaporation (MAPLE) is suitable to produce biopolymer/polymer film …

Rapid Segmentation Techniques For Cardiac And Neuroimage Analysis, Martin Rajchl

Electronic Thesis and Dissertation Repository

Recent technological advances in medical imaging have allowed for the quick acquisition of highly resolved data to aid in diagnosis and characterization of diseases or to guide interventions. In order to to be integrated into a clinical work flow, accurate and robust methods of analysis must be developed which manage this increase in data. Recent improvements in in- expensive commercially available graphics hardware and General-Purpose Programming on Graphics Processing Units (GPGPU) have allowed for many large scale data analysis problems to be addressed in meaningful time and will continue to as parallel computing technology improves. In this thesis we propose …

3d Fusion Of Histology To Multi-Parametric Mri For Prostate Cancer Imaging Evaluation And Lesion-Targeted Treatment Planning, Eli Gibson

Electronic Thesis and Dissertation Repository

Multi-parametric magnetic resonance imaging (mpMRI) of localized prostate cancer has the potential to support detection, staging and localization of tumors, as well as selection, delivery and monitoring of treatments. Delineating prostate cancer tumors on imaging could potentially further support the clinical workflow by enabling precise monitoring of tumor burden in active-surveillance patients, optimized targeting of image-guided biopsies, and targeted delivery of treatments to decrease morbidity and improve outcomes. Evaluating the performance of mpMRI for prostate cancer imaging and delineation ideally includes comparison to an accurately registered reference standard, such as prostatectomy histology, for the locations of tumor boundaries on mpMRI. …

Evaluating Human Performance For Image-Guided Surgical Tasks, Matthew Kenneth Kramers

Electronic Thesis and Dissertation Repository

The following work focuses on the objective evaluation of human performance for two different interventional tasks; targeted prostate biopsy tasks using a tracked biopsy device, and external ventricular drain placement tasks using a mobile-based augmented reality device for visualization and guidance. In both tasks, a human performance methodology was utilized which respects the trade-off between speed and accuracy for users conducting a series of targeting tasks using each device. This work outlines the development and application of performance evaluation methods using these devices, as well as details regarding the implementation of the mobile AR application. It was determined that the …

Potential For Photoacoustic Imaging Of Neonatal Brain, Pantea Tavakolian

Electronic Thesis and Dissertation Repository

Photoacoustic imaging is a hybrid imaging technique that combines many of the merits of both optical and ultrasound imaging. Photoacoustic imaging (PAI) has been hypothesized as a technique for imaging neonatal brain. However, PAI of the brain is more challenging than traditional methods (e.g. near infrared spectroscopy) due to the presence of the skull layer. To evaluate the potential limits the skull places on 3D PAI of the neonatal brain, we constructed a neonatal skull phantom (~1.52-mm thick) with a mixture of epoxy and titanium dioxide powder that provided acoustic insertion loss (1-5MHz) similar to human infant skull bone. The …

Curcumin-Loaded Magnetic Nanoaggregates Conjugated With Folic Acid For Targeted Cancer Treatment, Melessa Salem

Electronic Thesis and Dissertation Repository

Cancer has been, and still remains, one of the most complicated diseases to treat. As a result of the side effects experienced from current cancer treatment methods, there has been a growing interest in the development of targeted drug delivery systems that can destroy cancer cells, but render healthy tissue unharmed. To address this challenge, magnetite nanoaggregates were synthesized through the precipitation of iron oxide in the presence of polymers, conjugated with folic acid for folate targeting, and loaded with curcumin for cancer treatment. The resulting magnetite nanoparticles were 10 – 20 nm in size and the aggregates formed varied …

Human Metaphase Chromosome Analysis Using Image Processing, Akila M.S Subasinghe Arachchige

Electronic Thesis and Dissertation Repository

Development of an effective human metaphase chromosome analysis algorithm can optimize expert time usage by increasing the efficiency of many clinical diagnosis processes. Although many methods exist in the literature, they are only applicable for limited morphological variations and are specific to the staining method used during cell preparation. They are also highly influenced by irregular chromosome boundaries as well as the presence of artifacts such as premature sister chromatid separation.

Therefore an algorithm is proposed in this research which can operate with any morphological variation of the chromosome across images from multiple staining methods. The proposed algorithm is capable …

Functional Co-Substituted Poly[(Amino Acid Ester)Phosphazene] Biomaterials, Amanda L. Baillargeon

Electronic Thesis and Dissertation Repository

The development of new and improved biomaterials is essential for tissue engineering and regenerative medicine applications. Amino acid-based polyphosphazenes are being explored as scaffold materials for tissue engineering applications due to their non-toxic degradation products and tunable material properties. This work focuses on the synthesis of non-functional and novel functional poly[(amino acid ester)phosphazene]s using a facile method of thermal ring opening polymerization followed by one-pot room temperature substitution. The family of polyphosphazenes developed in this work is based on L-alanine (PNEAs), L-phenylalanine (PNEFs), and L-methionine (PNEMs) with L-glutamic acid imparting the functionality. Characterization of these materials demonstrated that the one-pot …

Plasmonic Optical Sensors: Performance Analysis And Engineering Towards Biosensing, Peipei Jia

Electronic Thesis and Dissertation Repository

Surface plasmon resonance (SPR) sensing for quantitative analysis of chemical reactions and biological interactions has become one of the most promising applications of plasmonics. This thesis focuses on performance analysis for plasmonic sensors and implementation of plamonic optical sensors with novel nanofabrication techniques.

A universal performance analysis model is established for general two-dimensional plasmonic sensors. This model is based on the fundamental facts of surface plasmon theory. The sensitivity only depends on excitation light wavelength as well as dielectric properties of metal and dielectrics. The expression involves no structure-specified parameters, which validates this formula in broad cases of periodic, quasiperiodic …

Image-Based Registration Methods For Quantification And Compensation Of Prostate Motion During Trans-Rectal Ultrasound (Trus)-Guided Biopsy, Tharindu De Silva

Electronic Thesis and Dissertation Repository

Prostate biopsy is the clinical standard for cancer diagnosis and is typically performed under two-dimensional (2D) transrectal ultrasound (TRUS) for needle guidance. Unfortunately, most early stage prostate cancers are not visible on ultrasound and the procedure suffers from high false negative rates due to the lack of visible targets. Fusion of pre-biopsy MRI to 3D TRUS for targeted biopsy could improve cancer detection rates and volume of tumor sampled. In MRI-TRUS fusion biopsy systems, patient or prostate motion during the procedure causes misalignments in the MR targets mapped to the live 2D TRUS images, limiting the targeting accuracy of the …

Mr To Ultrasound Registration For Image-Guided Prostate Biopsy, Yue Sun

Electronic Thesis and Dissertation Repository

Transrectal ultrasound (TRUS) guided prostate biopsy is the standard approach for diagnosis of prostate cancer (PCa). However, due to the lack of image contrast of prostate tumors, it often results in false negatives. Magnetic Resonance Imaging (MRI) has been considered to be a promising imaging modality for noninvasive identification of PCa, since it can provide a high sensitivity and specificity for the detection of early stage PCa. Our main objective is to develop a registration method of 3D MR-TRUS images, allowing generation of volumetric 3D maps of targets identified in 3D MR images to be biopsied using 3D TRUS images. …

Nasopharyngeal Method For Selective Brain Cooling And Development Of A Time-Resolved Near-Infrared Technique To Monitor Brain Temperature And Oxidation Status During Hypothermia, Mohammad Fazel Bakhsheshi

Electronic Thesis and Dissertation Repository

Mild hypothermia at 32-35^oC (HT) has been shown to be neuroprotective for neurological emergencies following severe head trauma, cardiac arrest and neonatal asphyxia. However, HT has not been widely deployed in clinical settings because: firstly, cooling the whole body below 33-34°C can induce severe complications; therefore, applying HT selectively to the brain could minimize adverse effects by maintaining core body temperature at normal level. Secondly, development of an effective and easy to implement selective brain cooling (SBC) technique, which can quickly induce brain hypothermia while avoiding complications from whole body cooling, remains a challenge. In this thesis, we …

Oriented Collagen And Applications Of Waveguide Evanescent Field Scattering (Wefs) Microscopy, Qamrun Nahar

Electronic Thesis and Dissertation Repository

In this thesis, Waveguide Evanescent Field Scattering (WEFS) microscopy is developed as a non-invasive, label-free live cell imaging technique. This new high-contrast imaging can be employed to study the first hundred nanometers from the surface as it utilizes the evanescent field of a waveguide as the illumination source. Previously, waveguide evanescent field fluorescence (WEFF) microscopy was developed as a fluorescence imaging technique comparable to the total internal reflection fluorescent (TIRF) microscopy. Both the WEFF and WEFS technique utilizes the same fundamental concepts except in WEFS microscopy imaging is accomplished without the application of any fluorescent labeling. In this work, bacterial …

Humidity Effect On The Structure Of Electrospun Core-Shell Pcl-Peg Fibers For Tissue Regeneration Applications, Adam P. Golin

Electronic Thesis and Dissertation Repository

With the aim of creating a biodegradable scaffold for tympanic membrane (TM) tissue regeneration, core-shell nanofibers composed of a poly(caprolactone) shell and a poly(ethylene glycol) core were created using a coaxial electrospinning technique. In order to create fibers with an optimal core-shell morphology, the effect of relative humidity (RH) on the core-shell nanofibers was systematically studied, with a FITC-BSA complex encapsulated in the core to act as a model protein. The core-shell nanofibers were electrospun at relative humidity values of 20, 25, 30, and 40% RH within a glove box outfitted for humidity control. The core-shell morphology of the fibers …

The Development And Application Of A Forearm Simulator To Investigate Radial Head Biomechanics, Brent A. Lanting

Electronic Thesis and Dissertation Repository

The forearm is a complex articular unit, with poorly understood biomechanics. A novel forearm simulator to facilitate physiologic testing of cadavers for multiple clinical scenarios was designed, manufactured and validated. A number of outcome measurements were potentiated including the forearm’s resistance to rotation, radiocapitellar contact pressure and area as well as IOM loads. Testing of changes to forearm biomechanics due to radial head excision and variations of radial head arthroplasty dimensions was conducted. Radial head arthroplasty using the correct radial head length and diameter recreated the biomechanics of an intact forearm. Radial head excision as well an implant of non-anatomic …