Browsing by Author "Komeili, Amin"

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    3D Markerless asymmetry analysis in the management of adolescent idiopathic scoliosis
    (2018-10-24) Ghaneei, Maliheh; Komeili, Amin; Li, Yong; Parent, Eric C; Adeeb, Samer
    Abstract Background Three dimensional (3D) markerless asymmetry analysis was developed to assess and monitor the scoliotic curve. While the developed surface topography (ST) indices demonstrated a strong correlation with the Cobb angle and its change over time, it was reported that the method requires an expert for monitoring the procedure to prevent misclassification for some patients. Therefore, this study aimed at improving the user-independence level of the previously developed 3D markerless asymmetry analysis implementing a new asymmetry threshold without compromising its accuracy in identifying the progressive scoliotic curves. Methods A retrospective study was conducted on 128 patients with Adolescent Idiopathic Scoliosis (AIS), with baseline and follow-up radiograph and surface topography assessments. The suggested “cut point” which was used to separate the deformed surfaces of the torso from the undeformed regions, automatically generated deviation patches corresponding to scoliotic curves for all analyzed surface topography scans. Results By changing the “cut point” in the asymmetry analysis for monitoring scoliotic curves progression, the sensitivity for identifying curve progression was increased from 68 to 75%, while the specificity was decreased from 74 to 59%, compared with the original method with different “cut point”. Conclusions These results lead to a more conservative approach in monitoring of scoliotic curves in clinical applications; smaller number of radiographs would be saved, however the risk of having non-measured curves with progression would be decreased.
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    Design and development of a microfluidic integrated electrochemical nanobiosensor for detection of SARS-CoV-2 Nucleocapsid protein biomarker
    (2021-12-13) Haghayegh, Fatemeh; Sanati-Nezhad, Amir; Dalton, Colin; Komeili, Amin
    The rapid spread of infectious disease outbreaks, such as the COVID-19 pandemic, once again emphasized the importance of deploying the potentials of biosensing technologies, as a key tool for controlling further transmission. Although the gold standard technique, Polymerase Chain Reaction (PCR), has become swiftly adopted, their limitations ask for more rapid, time-saving, and miniaturized approaches, such as all-in-one portable diagnostic platforms. Depending on the biosensing approach, the sensing element and the fluid-handling segment are considered as the most important elements of such platforms. As for the sensing methods, electrochemical immunosensing proved to have the sensitivity required for detecting the low amount of target proteins, which is favorable for early-disease detection, only if the surface of the sensor is modified to exhibit a high capacity for specific probe immobilization. Hence, introducing highly receptive surfaces is important for enhancing the sensitivity. For utilizing electrochemical immunosensors in point-of-care devices, the challenge of accommodating all of the conventionally lab-centralized sensing processes into one single chip also requires further research and investigation. To this end, the focus of the present thesis was to introduce an ultrasensitive nano-biosensor based on Zinc Oxide (ZnO) and Reduced Graphene Oxide (rGO) nanocomponents, which could successfully create a highly porous and stable sensing surface. The coated electrodes were functionalized with an L-cysteine cross-linker to provide abundant sources of carboxylic acid functional groups, an essential moiety for antibody immobilization. The morphology, physical and chemical characteristics of the sensing surface were thoroughly analyzed using spectroscopy and microscopy techniques. The electrochemical impedance spectroscopy (EIS) experiments confirmed the functionality of the immunosensor for detecting as low as 21 fg/mL SARS-CoV-2 biomarker, the Nucleocapsid (N-) protein, while it was further used for clinically detecting positive clinical swab samples. The integration of the biosensor into a microfluidic testing kit was also been explored, with a novel redox-contained chip automating all steps of immunosensing in one single kit. The platform successfully operated within 15 min for detecting N-proteins of the nasopharyngeal (NP) swab sample. This electrochemical biosensor integrated within the accompanying microfluidic chip provides a promising perspective towards the realization of a point-of-care platform.
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    Enhancing the Efficiency of Subject-Specific Knee Joint Biomechanical Simulations With Applications to Osteoarthritis
    (2024-08-14) Kakavand, Reza; Komeili, Amin; Edwards, William Brent; Abbasi, Zahra; Souza, Roberto M.
    There are three challenges in conventional subject-specific modelling techniques. First, having an accurate material model is essential for studying biomechanical response of musculoskeletal systems. For instance, the stresses and strains in knee joint articular cartilage are influenced by site-specific variations in collagen fibril orientations that vary with aging, which is ignored in finite element (FE) analyses using a generic knee geometry. The other challenge is related to the manual geometry reconstruction from biomedical images, which is a time-consuming process and not practical for clinical applications. Finally, estimating joint forces and moments with conventional methods requires marker-based motion capture facilities to study the kinematics of human body motion and convoluted human body modeling to determine the kinetics of motions. Although marker-based motion capture offers the precise measurement of marker positions on the body and enables the calculation of kinematics and kinetics in a controlled setting, its data collection is labor-intensive and requires staff with expensive equipment and specialized technical experience. Subject-specific FE modeling provides a viable approach for the study of cartilage mechanics in normal and pathomorphological knee, thus providing insight into the mechanics of knee articular cartilage. Therefore, in this project we aimed to facilitate the development of subject-specific FE models of the knee. We developed and validated: 1) a 3D remodeling algorithm of collagen fibrils within knee joint cartilage under simulated gait, 2) a semi-automatic segmentation routine of knee joint geometry from magnetic resonance images (MRIs), and 3) a markerless motion capture to perform kinematics and kinetics analyses. To develop the cartilage fibril remodeling algorithm, a fibril-reinforced, biphasic cartilage model was integrated with 3D human knee joint geometry. For the MRI segmentation, we used 3D Swin UNETR, a statistical shape model (SSM) and automated filtering techniques to extract the distal femur, proximal tibia, femoral and tibial cartilages. To facilitate the estimation of joint forces and moments, OpenCap, a markerless motion capture software, was used during a cycling task. This technique is intended to expedite kinematics and kinetics analysis. The ultimate goal of this project is to develop an efficient pipeline for subject-specific FE modeling.
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    Self-healing of Direct Written Conductive Inks for Curvilinear Circuits
    (2023-04-18) Jeong, Chan Woo (Robin); Park, Simon; Du, Ke; Abbasi, Zahra; Komeili, Amin
    The increased electrification of vehicles in both automotive and aerospace industries has introduced new challenges in manufacturing complexities and weight management. Complex and heavy wirings are currently being utilized and conventional printed circuit board (PCB) manufacturing methods are limited in 2D geometries. Alternatively, a direct-writing approach presents weight and materials saving opportunities where planar substrates with circuits already printed are formed to a final shape. However, designing a circuit or a printed ink formula able to withstand the high strain of substrate forming is challenging. Instead, a circuit able to regain functionality after sustaining strain induced cracks presents a more versatile approach. In this study, a conductive ink with self-healing capabilities is developed. A copper-nanoparticle based ink compatible with existing lithographic methods is developed and printed on planar polymeric substrates. Intense pulsed light (IPL) is utilized to photothermally heat, reduce, and sinter copper nanoparticles within milliseconds. By utilizing light-matter energy absorption and the plasmonic effect, heat sensitive polymeric substrates are unaffected while conductive copper tracks are formed. After printing, drying, and IPL flashing, the substrate and printed tracks are subjected to cyclic bending and thermoforming. Afterwards flashing is performed once again to initiate the healing process through reflow of indium microparticles. These indium healing agents added to the ink bridges microcracks via capillary forces to recover severed electron pathways. Mechanisms of photothermal heating and sintering is simulated to better understand the underlying physical phenomena. Ultimately, a planarly written copper nanoparticle ink capable of surviving substrate deformation to produce curvilinear circuits is achieved. This direct writing method can provide drastic wiring weight reduction imparting fuel savings in the next generation of electronics in vehicles.
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    The importance of intervertebral disc material model on the prediction of mechanical function of the cervical spine
    (2021-04-02) Komeili, Amin; Rasoulian, Akbar; Moghaddam, Fatemeh; El-Rich, Marwan; Li, Le P
    Abstract Background Linear elastic, hyperelastic, and multiphasic material constitutive models are frequently used for spinal intervertebral disc simulations. While the characteristics of each model are known, their effect on spine mechanical response requires a careful investigation. The use of advanced material models may not be applicable when material constants are not available, model convergence is unlikely, and computational time is a concern. On the other hand, poor estimations of tissue’s mechanical response are likely if the spine model is oversimplified. In this study, discrepancies in load response introduced by material models will be investigated. Methods Three fiber-reinforced C2-C3 disc models were developed with linear elastic, hyperelastic, and biphasic behaviors. Three different loading modes were investigated: compression, flexion and extension in quasi-static and dynamic conditions. The deformed disc height, disc fluid pressure, range of motion, and stresses were compared. Results Results indicated that the intervertebral disc material model has a strong effect on load-sharing and disc height change when compression and flexion were applied. The predicted mechanical response of three models under extension had less discrepancy than its counterparts under flexion and compression. The fluid-solid interaction showed more relevance in dynamic than quasi-static loading conditions. The fiber-reinforced linear elastic and hyperelastic material models underestimated the load-sharing of the intervertebral disc annular collagen fibers. Conclusion This study confirmed the central role of the disc fluid pressure in spinal load-sharing and highlighted loading conditions where linear elastic and hyperelastic models predicted energy distribution different than that of the biphasic model.