Master of Science, University of Toledo, 2021, Exercise Science

Abstract: Objective: To use SPORTS Ultrasound (US) to measure the transverse abdominis (TrA) activity of healthy active population during commonly prescribed therapeutic exercises. Design: Descriptive laboratory study. Setting: University research laboratory. Participants: Nineteen healthy participants (age, 22.89±1.56 years; height, 1.72±.08 m; mass, 72.56±12.03 kg). Main Outcome Measures: The activation ratio of TrA (ARTrA) and preferential activation ratio of the TrA (PARTrA) in four tasks varying in functionality were assessed. The tasks were an abdominal draw-in maneuver (ADIM), quadruped, quadruped with contralateral limb movement, and standing resisted rotation. Statistical analysis included means and 95% confidence intervals for the activation ratio and preferential activation ratio for each task. Repeated Measure ANOVAs with post-hoc comparisons to look for differences between tasks, p<0.05 were also included. Results: The resting TrA thickness measurements were statistically different depending on resting position, p<0.001. Quiet hook-lying (HLQ) < Quiet Quadruped. Quiet HLQ < Quiet Standing. Quiet Quadruped = Quiet Standing. The lateral abdominal wall musculature (LAWM) thickness was not statistically different in varying positions. The ADIM produced the largest ARTrA. Each task produced an ARTrA>1.0 indicating activation of the TrA, p<0.002. The moving quadruped task produced the greatest ARTrA of the two dynamic tasks. Nearly 90% of participants were able to achieve an ARTrA>1.0 in the standing resisted rotation task without cueing an ADIM. Conclusions: This is the first study to demonstrate TrA activation in a rotation-based exercise without cueing an ADIM. There may be more functional options to exercise the TrA and clinicians can look to move beyond supine. The demonstration of an ARTrA>1.0 during a rotational task without cueing opens doors for biofeedback and advanced, functional exercise progressions.

Committee: David Bazett-Jones (Committee Chair); Neal Glaviano (Committee Member); Grant Norte (Committee Member); Amanda Murray (Committee Member); Erika Zambarano (Committee Member); Colby Mangum (Committee Member) Subjects: Kinesiology; Medical Imaging; Sports Medicine

PhD, University of Cincinnati, 2017, Engineering and Applied Science: Biomedical Engineering

Ischemic stroke affects nearly 700,000 patients in the United States each year and is the fifth most common cause of death. In less than 6% of ischemic stroke patients, lysis of the occlusive clot is attempted with recombinant tissue-plasminogen activator (rt-PA). The addition of Definity® microbubbles and 120-kHz ultrasound to rt-PA treatment has been shown to enhance lytic activity in vitro and ex vivo. However, preclinical trials must be completed in an animal model such as pigs prior to human clinical trials. One porcine thrombosis model is the intracerebral hemorrhage model, in which an intracerebral hemorrhage is treated with a lytic and exposed to ultrasound. An assay for a biochemical marker of clot breakdown, D-dimer, was evaluated for quantification of thrombolysis in this model. A porcine D-dimer purification protocol was developed and the identity of the purified D-dimer was confirmed by immunoblotting and MALDI TOF-TOF analysis. We evaluated a commercially available D-dimer ELISA kit and 5 commercially available D-dimer antibodies for development of an in-house ELISA protocol. In porcine samples produced in an in vitro thrombolysis system, D-dimer concentration was shown to correlate with mass loss. However, no current assay is known to be able to quantitate D-dimer with adequate sensitivity (10 ng/mL). To create an arterial thromboembolism model of ischemic stroke, porcine ascending pharyngeal arteries (APA) were occluded bilaterally. Most arteries were occluded with a single clot chosen to be about 1 mm larger than the inner diameter of the target artery. However, intraarterial treatment of the occluded arteries with rt-PA was ineffective and did not recanalize any of the occluded arteries. A protocol for post-mortem APA excision from swine was also developed. The lack of rt-PA efficacy in the porcine arterial thromboembolism model suggested that porcine clots were resistant to rt-PA thrombolysis. In vitro evaluation of the lytic response o (open full item for complete abstract)

Committee: Christy Holland Ph.D. (Committee Chair); Todd Abruzzo Ph.D. (Committee Member); Kevin Haworth Ph.D. (Committee Member); Andrew Herr Ph.D. (Committee Member); Daria Narmoneva Ph.D. (Committee Member) Subjects: Biomedical Research

PhD, University of Cincinnati, 2016, Engineering and Applied Science: Mechanical Engineering

Techniques for predicting high intensity focused ultrasound (HIFU) pressure fields in tissue using measured pressures in water are called derating techniques. These techniques are valuable for characterizing the HIFU systems prior to use in animals or humans. One common technique, called linear derating, assumes linear wave propagation in both water and tissue and involves reducing the measured pressures in water by the tissue attenuation to account for the losses in tissue. However, neglecting nonlinear propagation effects in the derating process can cause significant errors. This dissertation presents a nonlinear derating technique to estimate HIFU nonlinear pressure fields and temperature rise in tissue using pressure measurements made in water. The method is based on an evolution equation in tissue which is derived assuming a Gaussian functional dependence for each harmonic in the radial direction. The nonlinear term in the evolution equation is modeled using modal amplitudes measured in water and suitably reduced using a combination of source derating (lower acoustic source pressure in water than in tissue) and endpoint derating (reduction in amplitudes at the target location). The resulting linear ordinary differential equations are solved to obtain an estimate of the tissue modal amplitudes. Numerical validation of the derating technique is performed using the computed acoustic pressure measurements in water for transducers with Gaussian and uniform shadings. The simulated modal amplitudes in water for the three different transducer gains of 20, 40 and 60 are used in the nonlinear derating algorithm to estimate the focal acoustic pressures in tissue. In addition, the derated modal amplitudes for the transducers with uniform shadings are used in the Green function solution of the bioheat equation to predict the HIFU induced focal temperature rise in tissue. The estimated acoustic pressures and temperature rises by the derating technique are com (open full item for complete abstract)

Committee: Rupak Banerjee Ph.D P.E. (Committee Chair); Matthew R. Myers Ph.D. (Committee Member); Michael Kazmierczak Ph.D. (Committee Member); Jay Kim Ph.D. (Committee Member); Sang Young Son Ph.D. (Committee Member) Subjects: Mechanical Engineering

MS, University of Cincinnati, 2015, Engineering and Applied Science: Biomedical Engineering

Ultrasound-enhanced thrombolysis (UET) is under development as an adjuvant to thrombolytic administration for the treatment of ischemic stroke. Initial studies have demonstrated the efficacy of UET in the presence of ultrasound contrast agents (UCAs), stabilized microbubbles that can be injected into the bloodstream. These studies demonstrated ultrasound-enhanced thrombolysis when acoustic emissions characteristic of stable cavitation, ultraharmonics (UH) and the subharmonic (SH), were present. The current study was performed to determine the threshold for cavitation activity in an in- vitro human clot model in flow exposed to an UCA and 120-kHz pulsed or continuous wave ultrasound. Two UCAs were used to nucleate cavitation, Definity® and echogenic liposomes (ELIP). Definity® is a commercially available UCA, and ELIP are potential theragnostic agents for the treatment of stroke, with the potential to encapsulate and release drugs, such as the thrombolytic drug recombinant tissue-plasminogen activator (rt-PA), upon exposure to ultrasound. UH and broadband (BB) cavitation thresholds occurred at the same acoustic pressure (0.3 ± 0.1 MPa, peak-to-peak) for both UCAs, and were mostly independent of the ultrasound duty cycle.

Committee: Christy Holland Ph.D. (Committee Chair); T. Douglas Mast Ph.D. (Committee Member); Marepalli Rao Ph.D. (Committee Member) Subjects: Biomedical Research

PhD, University of Cincinnati, 2007, Engineering : Biomedical Engineering

Pulsed ultrasound, when used as an adjuvant to a thrombolytic, such as recombinant tissue plasminogen activator (rt-PA), could enhance therapeutic efficacy. Such enhancement would represent a significant breakthrough in the treatment of diseases like ischemic stroke, myocardial infarction, pulmonary embolism and deep vein thrombosis. Acoustic cavitation was hypothesized in this work to be the underlying mechanism responsible for thrombolytic enhancement. Existing theoretical models were employed to predict rectified diffusion and cavitation thresholds at 120 kHz. Stable and inertial cavitation thresholds were measured experimentally and clots were exposed to cavitational activity in the presence of rt-PA. Subsequently, an approach for cavitation nucleation using infusion of a contrast agent was tested experimentally in vitro. Finally, a technique for stable cavitation monitoring was developed which tracks the ultraharmonic emissions during the combined ultrasound and thrombolytic exposures in a human blood clot model. The stable cavitation activity was measured during clot mass loss experiments. A dual antibody immunofluorescence technique was employed to measure penetration depths of rt-PA and plasminogen into the clots. Porcine whole blood clots, when exposed to stable cavitation activity in the presence of rt-PA, resulted in the highest mass loss of 26.0 ± 4 %. The presence of inertial cavitation lowered the mass loss to 20.7 ± 1.6 %. A commercial contrast agent, Definity®, was successfully used to promote and sustain the nucleation of stable cavitation during pulsed ultrasound exposure at 120 kHz for 30 min. The largest clot mass loss of 26.2 ± 2.6 % was observed in human whole blood clots in the presence of sustained stable cavitation activity. A significant correlation was observed between clot mass loss and ultraharmonic signals (r=0.8549, p<0.0001, n=24). The largest mean penetration depth of rt-PA (222 µm) and plasminogen (241 µm) was observed in the presen (open full item for complete abstract)

Committee: Dr. Christy Holland (Advisor) Subjects:

Doctor of Philosophy, The Ohio State University, 2005, Physical Activity and Educational Services

Non-thermal ultrasound (US) is commonly used in an attempt to improve tissue repair and regeneration, although the efficacy of this practice is not firmly established. Previous research has investigated only a few dependent variables at discreet points in time. Therefore, the purposes of these studies were to examine the influence of non-thermal ultrasound markers on skeletal muscle regeneration and to compare 4 different combinations of duty cycle and SAI representing two common SATA intensities. Design and Setting: Multifactorial designs comparing treatment, duty cycle, SATA, and time were used. A bilateral contusion injury to the gastrocnemius via a drop mass technique was performed. US administration commenced 24-hr post-injury and was delivered 5minutes daily on 4 consecutive days. Rats received the US treatment on their left hindlimb, and the contralateral right hindlimb served as a non-US control. Subjects: Male Wistar rats were used in this study and the protocol was ILACUC approved. Measurements: Dependent variables included muscle mass, fiber cross-sectional area, centrally localized nuclei, embryonic myosin heavy chain, MGF (muscle specific IGF-1), M-cadherin, and MyoD. Data were analyzed using a factorial MANOVA. Results: US increased muscle mass more than no treatment (P < 0.0001) and increases in muscle mass were found with the continuous US treatment compared to the pulsed duty cycle treatment at the same SATA (P = 0.019). In the second experiment, ultrasound treatments also statistically significantly affected MGF levels compared to non-treated hind limb (P = 0.029). There was an effect observed for the day post-injury for MGF (P = 0.014). Post-hoc testing revealed that the MGF value on 1 day post-injury was statistically greater than the values observed for days 3 and 4 after injury. Conclusions: The specific non-thermal ultrasound treatments we studied had beneficial effects on skeletal muscle regeneration following blunt trauma. When comparing US (open full item for complete abstract)

Committee: Steven Devor (Advisor) Subjects: