@article{roy_guddati_2023, title={Full waveform inversion for arterial viscoelasticity}, volume={68}, ISSN={["1361-6560"]}, DOI={10.1088/1361-6560/acba7a}, abstractNote={Abstract}, number={5}, journal={PHYSICS IN MEDICINE AND BIOLOGY}, author={Roy, Tuhin and Guddati, Murthy N.}, year={2023}, month={Mar} }
 @article{capron_roy_guddati_urban_2023, title={Improving group velocity based estimates of arterial stiffness}, volume={153}, ISSN={["1520-8524"]}, DOI={10.1121/10.0018801}, abstractNote={Arterial stiffness is a predictor of cardiovascular diseases, the leading causes of death worldwide. Ultrasound-based methods that measure arterial wave propagation have promise for evaluating local stiffness in vivo. However, geometric properties of arteries cause dispersion, invalidating typical assumptions underlying the relationship between shear modulus G and group velocity cg, which clinical implementations of ultrasound shear wave elastography do not consider. Here, we examine the dependence of these estimates on geometry and evaluate alternative approaches. Wave motion in the proximal wall of an artery after application of focused acoustic radiation force is simulated with a semi-analytical finite element (SAFE) model, and cg is estimated using a time-to-peak algorithm to determine G with several methods. First, the value of G a clinical scanner would report is calculated assuming a bulk medium. Second, a pulse wave velocity (PWV)-based G estimate is calculated by taking cg = PWV and applying the Moens–Korteweg equation. Third, we develop an interpolation-based method to provide a corrected G estimate using data generated by the SAFE model. Simulation results show severe geometry-dependent bias with the bulk method, which is partially ameliorated with the PWV method and substantially improved with the interpolation approach. Results are validated using arterial phantoms.}, number={3}, journal={JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA}, author={Capron, Charles and Roy, Tuhin and Guddati, Murthy and Urban, Matthew W.}, year={2023}, month={Mar} }
 @article{guddati_roy_elmeliegy_urban_2023, title={Shear wave elastography: From dispersion matching to full waveform inversion}, volume={153}, ISSN={["1520-8524"]}, DOI={10.1121/10.0018796}, abstractNote={Shear Wave Elastography (SWE) involves estimating mechanical properties through inversion, i.e., matching measured and simulated propagation characteristics of shear waves in the tissue. The accuracy of the estimated properties depends significantly on the specific characteristics/responses that are being matched. These could range from simple group velocity to dispersion curves and to full-wave response (particle velocity measurements). Using specific applications of arterial, liver, and tumor elstography, we illustrate that effective SWE is performed by resorting to an inversion approach, or combination of inversion approaches, guided by the underlying physics. To this end, we present inversion approaches ranging from matching dispersion characteristics to matching full waveform responses and provide rationale for choosing the appropriate technique(s) depending on the problem at hand.}, number={3}, journal={JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA}, author={Guddati, Murthy and Roy, Tuhin and Elmeliegy, Abdelrahman M. and Urban, Matthew W.}, year={2023}, month={Mar} }
 @article{roy_guddati_2022, title={Full wave simulation of arterial response under acoustic radiation force}, volume={149}, ISSN={["1879-0534"]}, DOI={10.1016/j.compbiomed.2022.106021}, abstractNote={With the ultimate goal of estimating arterial viscoelasticity using shear wave elastography, this paper presents a practical methodology to simulate the response of a human carotid artery under acoustic radiation force (ARF). The artery is idealized as a nearly incompressible viscoelastic hollow cylinder submerged in incompressible, inviscid fluid. For this idealization, we develop a multi-step methodology for efficient computation of three-dimensional response under complex ARF excitation, while capturing the fluid-structure interaction between the arterial wall and the surrounding fluid. The specific steps include (a) performing dimensional reduction through semi-analytical finite element formulation, (b) efficient finite element discretization using traditional and recent techniques. The computational efficiency is further enhanced by utilizing (c) modal superposition, followed by, where appropriate, (d) impulse response function. In addition to developing the methodology, convergence analysis is performed for a typical arterial geometry, leading to recommendations on various discretization parameters. At the end, the computational effort is shown to be several orders of magnitude less than the traditional, fully three-dimensional analysis using finite element methods, leading to a practical yet accurate simulation of arterial response under ARF excitations.}, journal={COMPUTERS IN BIOLOGY AND MEDICINE}, author={Roy, Tuhin and Guddati, Murthy N.}, year={2022}, month={Oct} }
 @article{lee_capron_liu_roy_guddati_greenleaf_urban_2022, title={Measurement of wave propagation through a tube using dual transducers for elastography in arteries}, volume={67}, ISSN={["1361-6560"]}, DOI={10.1088/1361-6560/ac9c3f}, abstractNote={Abstract}, number={22}, journal={PHYSICS IN MEDICINE AND BIOLOGY}, author={Lee, Hyoung-Ki and Capron, Charles B. and Liu, Hsiao-Chuan and Roy, Tuhin and Guddati, Murthy N. and Greenleaf, James F. and Urban, Matthew W.}, year={2022}, month={Nov} }
 @article{capriotti_roy_hugenberg_harrigan_lee_aquino_guddati_greenleaf_urban_2022, title={The influence of acoustic radiation force beam shape and location on wave spectral content for arterial dispersion ultrasound vibrometry}, volume={67}, ISSN={["1361-6560"]}, DOI={10.1088/1361-6560/ac75a7}, abstractNote={Abstract}, number={13}, journal={PHYSICS IN MEDICINE AND BIOLOGY}, author={Capriotti, Margherita and Roy, Tuhin and Hugenberg, Nicholas R. and Harrigan, Hadiya and Lee, Hon-Chi and Aquino, Wilkins and Guddati, Murthy and Greenleaf, James F. and Urban, Matthew W.}, year={2022}, month={Jul} }
 @inproceedings{roy_urban_greenleaf_guddati_2021, title={Arterial Stiffness Estimation with Shear Wave Elastography}, author={Roy, T. and Urban, M.W. and Greenleaf, J.F. and Guddati, M.N}, year={2021} }
 @article{liu_abbasi_ding_roy_capriotti_liu_fitzgerald_doyle_guddati_urban_et al._2021, title={Characterizing blood clots using acoustic radiation force optical coherence elastography and ultrasound shear wave elastography}, volume={66}, ISSN={["1361-6560"]}, url={https://doi.org/10.1088/1361-6560/abcb1e}, DOI={10.1088/1361-6560/abcb1e}, abstractNote={Abstract}, number={3}, journal={PHYSICS IN MEDICINE AND BIOLOGY}, publisher={IOP Publishing}, author={Liu, Hsiao-Chuan and Abbasi, Mehdi and Ding, Yong Hong and Roy, Tuhin and Capriotti, Margherita and Liu, Yang and Fitzgerald, Sean and Doyle, Karen M. and Guddati, Murthy and Urban, Matthew W. and et al.}, year={2021}, month={Feb} }
 @article{roy_urban_xu_greenleaf_guddati_2021, title={Multimodal guided wave inversion for arterial stiffness: methodology and validation in phantoms}, volume={66}, ISSN={["1361-6560"]}, url={https://doi.org/10.1088/1361-6560/ac01b7}, DOI={10.1088/1361-6560/ac01b7}, abstractNote={Abstract}, number={11}, journal={PHYSICS IN MEDICINE AND BIOLOGY}, publisher={IOP Publishing}, author={Roy, Tuhin and Urban, Matthew and Xu, Yingzheng and Greenleaf, James and Guddati, Murthy N.}, year={2021}, month={Jun} }
 @article{roy_guddati_2021, title={Shear wave dispersion analysis of incompressible waveguides}, volume={149}, ISSN={["1520-8524"]}, url={https://doi.org/10.1121/10.0003430}, DOI={10.1121/10.0003430}, abstractNote={A suite of methodologies is presented to compute shear wave dispersion in incompressible waveguides encountered in biomedical imaging; plate, tube, and general prismatic waveguides, all immersed in an incompressible fluid, are considered in this effort. The developed approaches are based on semi-analytical finite element methods in the frequency domain with a specific focus on the complexities associated with the incompressibility of the solid media as well as the simplification facilitated by the incompressibility of the surrounding fluid. The proposed techniques use the traditional idea of selective reduced integration for the solid medium and the more recent idea of perfectly matched discrete layers for the surrounding fluid. Also, used is the recently developed complex-length finite element method for platelike structures. Several numerical examples are presented to illustrate the practicality and effectiveness of the developed techniques in computing shear wave dispersion in a variety of waveguides.}, number={2}, journal={JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA}, publisher={Acoustical Society of America (ASA)}, author={Roy, Tuhin and Guddati, Murthy N.}, year={2021}, month={Feb}, pages={972–982} }
 @article{hugenberg_roy_harrigan_capriotti_lee_guddati_greenleaf_urban_aquino_2021, title={Toward improved accuracy in shear wave elastography of arteries through controlling the arterial response to ultrasound perturbation in-silico and in phantoms}, volume={66}, ISSN={["1361-6560"]}, url={https://doi.org/10.1088/1361-6560/ac38fe}, DOI={10.1088/1361-6560/ac38fe}, abstractNote={Abstract}, number={23}, journal={PHYSICS IN MEDICINE AND BIOLOGY}, publisher={IOP Publishing}, author={Hugenberg, Nicholas R. and Roy, Tuhin and Harrigan, Hadiya and Capriotti, Margherita and Lee, Hyoung-Ki and Guddati, Murthy and Greenleaf, James F. and Urban, Matthew W. and Aquino, Wilkins}, year={2021}, month={Dec} }
 @inproceedings{roy_urban_greenleaf_guddati_2020, title={Guided wave inversion for arterial stiffness}, volume={148}, ISSN={0001-4966}, url={http://dx.doi.org/10.1121/1.5146760}, DOI={10.1121/1.5146760}, abstractNote={Shear Wave Elastography (SWE) has been used to estimate arterial stiffness, an important biomarker for early cardiovascular diseases. In arterial SWE, the carotid artery is excited with acoustic radiation force and the observed wave propagation characteristics are used to estimate the arterial stiffness. We present an efficient guided wave inversion procedure, where the elastic modulus of the arterial wall is estimated by matching wave dispersion from experiments and simulation. Central to the proposed approach is an efficient forward model that computes the dispersion relation for the incompressible, immersed cylindrical tube; the model achieves high efficiency by combining semi-analytical finite element methods, selective reduced integration, and perfectly matched discrete layers. We utilize this forward model in an optimization framework to develop a streamlined methodology to estimate the modulus of the arterial wall. In this talk, we present the formulation of the method as well as validation using phantom experiments on 10 rubber tubes (VytaFlex-10), followed by preliminary work on inverting for the viscoelastic modulus.}, number={4}, booktitle={The Journal of the Acoustical Society of America}, publisher={Acoustical Society of America (ASA)}, author={Roy, Tuhin and Urban, Matthew W. and Greenleaf, James and Guddati, Murthy}, year={2020}, month={Oct}, pages={2450–2450} }
 @inproceedings{roy_urban_greenleaf_guddati_2020, title={Multimodal Inversion for Shear Modulus and Thickness of Arteries}, url={https://api.ltb.io/show/BHQIA}, author={Roy, T. and Urban, M.W. and Greenleaf, J.F. and Guddati, M.N}, year={2020} }
 @article{doshi_roy_parihar_2017, title={Reliability based inspection planning using fracture mechanics based fatigue evaluations for ship structural details}, volume={54}, ISSN={0951-8339}, url={http://dx.doi.org/10.1016/j.marstruc.2017.03.003}, DOI={10.1016/j.marstruc.2017.03.003}, abstractNote={Survey and inspection of ship structures is essential in order to monitor the integrity of the hull. With increasing ship size, the number of details susceptible to fatigue damage may be significant. Also as the ship nears the end of its design life, more effective inspections are required to ascertain the structural health of the ship. Reliability based inspection techniques are a possible way for ensuring the effectiveness of the surveys. In the present work, the applications of fracture mechanics based fatigue crack evaluations have been demonstrated to prepare reliability based inspection plans for a Very Large Crude Carrier (VLCC). Probabilistic considerations have been applied taking into account the uncertainty in various parameters related to the loads, materials as well as the parameters of fatigue crack growth. Scheme for updating of reliability of a given ship structural detail has been presented which employs Bayesian approach. Effect of utilization of various inspection techniques has been demonstrated. Various cases such as no-detection of crack, detection of crack with & without repair have been considered. Finally, the results have been also compared with the reliabilities in the current practice of fixed periodical inspections. The paper demonstrates that reliability based inspections are a feasible technique for integrity management of ship structural details while maintaining a practicable work schedule.}, journal={Marine Structures}, publisher={Elsevier BV}, author={Doshi, Karan and Roy, Tuhin and Parihar, Yogendra Singh}, year={2017}, month={Jul}, pages={1–22} }
 @book{roy_2014, place={Kharagpur, India}, title={Meso level discrete element modeling for localized failure in concrete}, institution={Indian Institute of Technology}, author={Roy, T.}, year={2014} }