Intelligent Cervical Spine Fracture Detection Using Deep Learning Methods

Cervical spine fractures constitute a critical medical emergency, with the potential for lifelong paralysis or even fatality if left untreated or undetected. Over time, these fractures can deteriorate without intervention. To address the lack of research on the practical application of deep learning techniques for the detection of spine fractures, this study leverages a dataset containing both cervical spine fractures and non-fractured computed tomography images. This paper introduces a two-stage pipeline designed to identify the presence of cervical vertebrae in each image slice and pinpoint the location of fractures. In the first stage, a multi-input network, incorporating image and image metadata, is trained. This network is based on the Global Context Vision Transformer, and its performance is benchmarked against popular deep learning image classification model. In the second stage, a YOLOv8 model is trained to detect fractures within the images, and its effectiveness is compared to YOLOv5. The obtained results indicate that the proposed algorithm significantly reduces the workload of radiologists and enhances the accuracy of fracture detection

Hydrodynamic and Geometric Stiffening Effects on the Out-of-Plane Waves of Submerged Cables

This study focuses on the relative importance of two sources of nonlinearities affecting submerged cable response. The first of these is the added fluid damping offered by the surrounding medium while the second is the geometric stiffening offered by the cable through finite extensions of its centerline. The contribution of each nonlinear effect, taken separately and in tandem, is evaluated herein through the study of structural waves that form in the (out-of-plane) direction normal to the cable equilibrium plane.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43320/1/11071_2004_Article_135260.pd

Francis Turbine Draft Tube Troubleshooting during Operational Conditions Using CFD Analysis

Hydropower plant vibrations due to pressure fluctuations and their troubleshooting methods are some of the most challenging issues in power plant operation and maintenance. This paper targets these fluctuations in a prototype turbine in two geometries: the initially approved design and the as-built design. Due to topographic conditions downstream, these geometries slightly differ in the draft tube height; the potential effect of such a slight geometrical change on the applicability of troubleshooting techniques is investigated. Therefore, the water flow was simulated using the CFD scheme at three operating points based on the SST k–ω turbulence model, while the injection of water/air was examined to decrease the pressure fluctuations in the draft tube, and the outputs were compared with no-injection simulations. The results show that a slight change in draft tube geometry causes the pressure fluctuations to increase 1.2 to 2.8 times after 4 s injecting at different operating points. The modification in the location of the air injection also could not reduce the increase in pressure fluctuations and caused a 3.6-fold increase in pressure fluctuations. Therefore, the results show that despite water/air injection being a common technique in the hydropower industry to reduce pressure fluctuations, it is effective only in the initially approved design geometry. At the same time, it has a reverse effect on the as-built geometry and increases the pressure fluctuations. This research highlights the importance of binding the construction phase with the design and troubleshooting stages and how slight changes in construction can affect operational issues.<br/

Rheological properties of bitumen modified with a combination of FT paraffin wax (sasobit®) and other additives

Fischer–Tropsch paraffin Sasobit® is a popular Warm Mix Asphalt (WMA) modifier applied to improve physi­cal and rheological properties of bitumen. Although there are a number of studies investigating the effects of sasobit on bitumen properties, little has been carried out on evaluation of bitumen modified by sasobit along with other additives. In this study, sasobit modified bitumen is used as the base condition and four common modifiers namely anti-stripping agent, Crumb Rubber (CR), Styrene–Butadiene–Styrene (SBS) and Polyphosphoric Acid (PPA) are added separately to the FT – Wax modified bitumen to evaluate the compatibility of these additives with sasobit. Morphological, rheological and physical properties of modified binders are studied using Fourier Transform Infrared Spectroscopy (FT-IR), Scan­ning Electron Microscopy (SEM), Dynamic Mechanical Analysis (DMA), Bending Beam Rheometer (BBR) alongside with conventional tests. Results show that although anti-stripping agent reduce bitumen viscosity and mixing/compac­tion temperatures of asphalt mixtures, it has significantly increased the stiffness of sasobit modified bitumen at low temperatures. Among all, sasobit and crumb rubber combination exhibited the best performance, especially at low and intermediate temperatures

Allogeneic Versus Autologous Derived Cell Sources for Use in Engineered Bone-Ligament-Bone Grafts in Sheep Anterior Cruciate Ligament Repair

The use of autografts versus allografts for anterior cruciate ligament (ACL) reconstruction is controversial. The current popular options for ACL reconstruction are patellar tendon or hamstring autografts, yet advances in allograft technologies have made allogeneic grafts a favorable option for repair tissue. Despite this, the mismatched biomechanical properties and risk of osteoarthritis resulting from the current graft technologies have prompted the investigation of new tissue sources for ACL reconstruction. Previous work by our lab has demonstrated that tissue-engineered bone-ligament-bone (BLB) constructs generated from an allogeneic cell source develop structural and functional properties similar to those of native ACL and vascular and neural structures that exceed those of autologous patellar tendon grafts. In this study, we investigated the effectiveness of our tissue-engineered ligament constructs fabricated from autologous versus allogeneic cell sources. Our preliminary results demonstrate that 6 months postimplantation, our tissue-engineered auto- and allogeneic BLB grafts show similar histological and mechanical outcomes indicating that the autologous grafts are a viable option for ACL reconstruction. These data indicate that our tissue-engineered autologous ligament graft could be used in clinical situations where immune rejection and disease transmission may preclude allograft use.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140234/1/ten.tea.2014.0422.pd

Fresh Versus Frozen Engineered Bone–Ligament–Bone Grafts for Sheep Anterior Cruciate Ligament Repair

Surgical intervention is often required to restore knee instability in patients with anterior cruciate ligament (ACL) injury. The most commonly used grafts for ACL reconstruction are tendon autografts or allografts. These current options, however, have shown failure rates requiring revision and continued instability in the long term. The mismatched biomechanical properties of the current tendon grafts compared with native ACL tissue are thought to contribute to these poor outcomes and potential risk of early onset osteoarthritis. As a possible solution to these issues, our laboratory has fabricated tissue-engineered ligament constructs that exhibit structural and functional properties similar to those of native ACL tissue after 6 months implantation. In addition, these tissue-engineered grafts achieve vascular and neural development that exceeds those of patellar tendon grafts. However, the utility of our tissue-engineered grafts is limited by the labor-intensive method required to produce the constructs and the need to use the constructs fresh, directly from the cell culturing system. Ideally, these constructs would be fabricated and stored until needed. Thus, in this study, we investigated the efficacy of freezing our tissue-engineered constructs as a method of preservation before use for ACL reconstruction. We hypothesized that frozen constructs would have similar histological and biomechanical outcomes compared with our fresh model. Our results showed that 6 months postimplantation as an ACL replacement graft, both our tissue-engineered fresh and frozen grafts demonstrated similar mechanical and histological outcomes, indicating that freezing is a suitable method for preserving and storing our graft before ACL reconstruction. The ability to use frozen constructs significantly increases the versatility of our graft technology expanding the clinical utility of our graft.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140250/1/ten.tec.2014.0542.pd

Wave propagation in elastic cables with and without fluid interaction.

The objective of this research is to develop linear and nonlinear theories of wave propagation in extended elastic cables with and without fluid interaction. The motivation for doing so is the need to understand the dynamic response of long cable suspensions, the high frequency/short wavelength response of shorter suspensions, and transient response phenomena. This objective is achieved through both analytical and numerical investigations for cables in air and in water. To this end, a mathematical model is derived for the three-dimensional nonlinear response of extended cables submerged in a surrounding quiescent fluid medium. An asymptotic form of this model is derived for the linear response of a cable in air having small equilibrium curvature. The linear model predicts decoupled in-plane and out-of-plane waves. The out-of-plane waves are non-dispersive and obey a classical theory. By contrast, the in-plane waves are dispersive and generate coupled longitudinal and transverse motions. Analysis of in-plane response reveals the existence of two distinct wave types: (1) transverse-dominant waves, (2) longitudinal-dominant waves whose characteristics are determined by two cut-off frequencies. Closed-form solutions demonstrate significant tension waves following disturbances or excitation in the normal direction. The nonlinear theory of submerged cables is also decomposed into waves lying in and orthogonal to the equilibrium plane. For the out-of-plane theory, attention focuses on two nonlinear mechanisms governing wave response; namely, (1) hydrodynamic drag, and (2) finite centerline stretching (geometric stiffening). The major effect of hydrodynamic drag is to attenuate cable response away from the excitation source and to do so sharply as the excitation frequency increases. The major effect of geometric stiffening is to increase the wave propagation speed. Like the analysis of out-of-plane waves, the analysis of nonlinear in-plane waves reveals that hydro-dynamic drag preferentially attenuates the transverse-dominant wave type. For submerged cables of finite extent, an interesting low frequency tensioning phenomenon is resolved. The maximum dynamic tension occurs at the first cut-off frequency and beyond the second cut-off frequency there is a very sharp reduction in the dynamic tension.Ph.D.Applied SciencesCivil engineeringMechanical engineeringOcean engineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/130198/2/9721944.pd