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Sample records for dense fluid shockwaves

  1. Shockwave based nonlinear optical manipulation in densely scattering opaque suspensions.

    PubMed

    Greenfield, Elad; Nemirovsky, Jonathan; El-Ganainy, Ramy; Christodoulides, Demetri N; Segev, Mordechai

    2013-10-01

    Optical manipulation of particulate-loaded, highly scattering (opaque) suspensions is considered impossible. Here we demonstrate theoretically and experimentally optical manipulation of the local properties of such opaque suspensions. We show that the optical forces exerted by multiply-scattered light give rise to dense shock fronts of particle concentration, propagating deep inside the opaque suspensions, where the optical field is completely diffuse. We exploit these waves to demonstrate a plethora of optofluidic manipulations, ranging from optical transport and concentration of large populations of nanoparticles, to light-induced 'writing' of concentrated spots in the suspensions and light-induced phase-transition from suspension to gel in localized volumes inside the fluids.

  2. Phase boundary of hot dense fluid hydrogen

    PubMed Central

    Ohta, Kenji; Ichimaru, Kota; Einaga, Mari; Kawaguchi, Sho; Shimizu, Katsuya; Matsuoka, Takahiro; Hirao, Naohisa; Ohishi, Yasuo

    2015-01-01

    We investigated the phase transformation of hot dense fluid hydrogen using static high-pressure laser-heating experiments in a laser-heated diamond anvil cell. The results show anomalies in the heating efficiency that are likely to be attributed to the phase transition from a diatomic to monoatomic fluid hydrogen (plasma phase transition) in the pressure range between 82 and 106 GPa. This study imposes tighter constraints on the location of the hydrogen plasma phase transition boundary and suggests higher critical point than that predicted by the theoretical calculations. PMID:26548442

  3. Packing frustration in dense confined fluids.

    PubMed

    Nygård, Kim; Sarman, Sten; Kjellander, Roland

    2014-09-01

    Packing frustration for confined fluids, i.e., the incompatibility between the preferred packing of the fluid particles and the packing constraints imposed by the confining surfaces, is studied for a dense hard-sphere fluid confined between planar hard surfaces at short separations. The detailed mechanism for the frustration is investigated via an analysis of the anisotropic pair distributions of the confined fluid, as obtained from integral equation theory for inhomogeneous fluids at pair correlation level within the anisotropic Percus-Yevick approximation. By examining the mean forces that arise from interparticle collisions around the periphery of each particle in the slit, we calculate the principal components of the mean force for the density profile--each component being the sum of collisional forces on a particle's hemisphere facing either surface. The variations of these components with the slit width give rise to rather intricate changes in the layer structure between the surfaces, but, as shown in this paper, the basis of these variations can be easily understood qualitatively and often also semi-quantitatively. It is found that the ordering of the fluid is in essence governed locally by the packing constraints at each single solid-fluid interface. A simple superposition of forces due to the presence of each surface gives surprisingly good estimates of the density profiles, but there remain nontrivial confinement effects that cannot be explained by superposition, most notably the magnitude of the excess adsorption of particles in the slit relative to bulk.

  4. Prediction of viscosity of dense fluid mixtures

    NASA Astrophysics Data System (ADS)

    Royal, Damian D.; Vesovic, Velisa; Trusler, J. P. Martin; Wakeham, William. A.

    The Vesovic-Wakeham (VW) method of predicting the viscosity of dense fluid mixtures has been improved by implementing new mixing rules based on the rigid sphere formalism. The proposed mixing rules are based on both Lebowitz's solution of the Percus-Yevick equation and on the Carnahan-Starling equation. The predictions of the modified VW method have been compared with experimental viscosity data for a number of diverse fluid mixtures: natural gas, hexane + hheptane, hexane + octane, cyclopentane + toluene, and a ternary mixture of hydrofluorocarbons (R32 + R125 + R134a). The results indicate that the proposed improvements make possible the extension of the original VW method to liquid mixtures and to mixtures containing polar species, while retaining its original accuracy.

  5. Characterization of warm dense matter (WDM) from high intensity laser driven shockwaves

    NASA Astrophysics Data System (ADS)

    Krauland, Christine; Wei, Mingsheng; Santos, Joao; Belancourt, Patrick; Theobald, Wolfgang; Keiter, Paul; Beg, Farhat

    2015-11-01

    Understanding the transport physics of an intense relativistic electron beam in various plasma regimes is crucial for many high-energy-density applications, such as fast heating for advanced ICF schemes and ion sources. Most short pulse laser-matter interaction experiments for electron transport studies have been performed with initially cold targets where the resistivity is far from that in warm dense and hot dense plasmas. In order to extend fast electron transport and energy coupling studies in pre-assembled plasmas, we must first characterize those regime possibilities. We present initial experiments conducted on the OMEGA EP laser (~ 1014 W/cm2) to characterize WDM created from the shock compression of low density (ρ0 ~ 330 mg/cc) CRF foams and solid Al foil targets. In foam targets, imaging x-ray Thomson scattering is used to measure spatial profiles of the temperature, ionization state and relative material density. The ASBO diagnostic and radiation hydrodynamics simulations deduce shock pressure in Al targets of various thicknesses. Details of the experiment and available data will be presented. The work was funded by the US DOE/NNSA NLUF Program.

  6. An efficient fully atomistic potential model for dense fluid methane

    NASA Astrophysics Data System (ADS)

    Jiang, Chuntao; Ouyang, Jie; Zhuang, Xin; Wang, Lihua; Li, Wuming

    2016-08-01

    A fully atomistic model aimed to obtain a general purpose model for the dense fluid methane is presented. The new optimized potential for liquid simulation (OPLS) model is a rigid five site model which consists of five fixed point charges and five Lennard-Jones centers. The parameters in the potential model are determined by a fit of the experimental data of dense fluid methane using molecular dynamics simulation. The radial distribution function and the diffusion coefficient are successfully calculated for dense fluid methane at various state points. The simulated results are in good agreement with the available experimental data shown in literature. Moreover, the distribution of mean number hydrogen bonds and the distribution of pair-energy are analyzed, which are obtained from the new model and other five reference potential models. Furthermore, the space-time correlation functions for dense fluid methane are also discussed. All the numerical results demonstrate that the new OPLS model could be well utilized to investigate the dense fluid methane.

  7. Test of a new heat-flow equation for dense-fluid shock waves.

    PubMed

    Holian, Brad Lee; Mareschal, Michel; Ravelo, Ramon

    2010-09-21

    Using a recently proposed equation for the heat-flux vector that goes beyond Fourier's Law of heat conduction, we model shockwave propagation in the dense Lennard-Jones fluid. Disequilibrium among the three components of temperature, namely, the difference between the kinetic temperature in the direction of a planar shock wave and those in the transverse directions, particularly in the region near the shock front, gives rise to a new transport (equilibration) mechanism not seen in usual one-dimensional heat-flow situations. The modification of the heat-flow equation was tested earlier for the case of strong shock waves in the ideal gas, which had been studied in the past and compared to Navier-Stokes-Fourier solutions. Now, the Lennard-Jones fluid, whose equation of state and transport properties have been determined from independent calculations, allows us to study the case where potential, as well as kinetic contributions are important. The new heat-flow treatment improves the agreement with nonequilibrium molecular-dynamics simulations under strong shock wave conditions, compared to Navier-Stokes.

  8. Test of a new heat-flow equation for dense-fluid shock waves.

    PubMed

    Holian, Brad Lee; Mareschal, Michel; Ravelo, Ramon

    2010-09-21

    Using a recently proposed equation for the heat-flux vector that goes beyond Fourier's Law of heat conduction, we model shockwave propagation in the dense Lennard-Jones fluid. Disequilibrium among the three components of temperature, namely, the difference between the kinetic temperature in the direction of a planar shock wave and those in the transverse directions, particularly in the region near the shock front, gives rise to a new transport (equilibration) mechanism not seen in usual one-dimensional heat-flow situations. The modification of the heat-flow equation was tested earlier for the case of strong shock waves in the ideal gas, which had been studied in the past and compared to Navier-Stokes-Fourier solutions. Now, the Lennard-Jones fluid, whose equation of state and transport properties have been determined from independent calculations, allows us to study the case where potential, as well as kinetic contributions are important. The new heat-flow treatment improves the agreement with nonequilibrium molecular-dynamics simulations under strong shock wave conditions, compared to Navier-Stokes. PMID:20866140

  9. Dense brushes of stiff polymers or filaments in fluid flow

    NASA Astrophysics Data System (ADS)

    Römer, F.; Fedosov, D. A.

    2015-03-01

    Dense filamentous brush-like structures are present in many biological interfacial systems (e.g., glycocalyx layer in blood vessels) to control their surface properties. Such structures can regulate the softness of a surface and modify fluid flow. In this letter, we propose a theoretical model which predicts quantitatively flow-induced deformation of a dense brush of stiff polymers or filaments, whose persistence length is larger or comparable to their contour length. The model is validated by detailed mesoscopic simulations and characterizes different contributions to brush deformation including hydrodynamic friction due to flow and steric excluded-volume interactions between grafted filaments. This theoretical model can be used to describe the effect of a stiff-polymer brush on fluid flow and to aid in the quantification of experiments.

  10. Self-Trapping of Light Particles in Dense Fluids

    NASA Astrophysics Data System (ADS)

    Reese, Terrence Lee

    1992-01-01

    A light particle (electron, positron, or positronium atom) thermalized in a dense fluid can in a certain range of density and temperature become localized in a region of altered fluid density. Because it is the presence of the light particle, lp, that initiates the localization process it is referred to as self-trapping. Self-Trapping results in non-linear dependence upon the density in experimental measurements of lp properties such as electron mobility and positron and positronium decay rate in fluids. Because of its small mass the lp has a thermal wavelength which is much greater than the thermal wavelength of the fluid molecules. Thus it is possible to treat the translational degrees of freedom by classical mechanics and the lp's degrees of freedom by quantum mechanics. This hybrid model is referred to as the adiabatic model. Density Functional Theory, DFT, and the Path Integral Monte Carlo, PIMC, technique are two approximations used to make calculations with the adiabatic model. DFT uses the Jensen inequality to approximate the trace over the lp wavefunction and calculate important equilibrium properties of an lp in a fluid. The PIMC technique uses the classical isomorphism to relate the partition function of a quantum particle to the partition function of a classical polymer. This relation allows the computation of quantum equilibrium averages by standard classical Monte Carlo methods. In this research the simplest variant of DFT and the PIMC technique are used to simulate positronium in dense fluids. DFT is shown to be able to qualitatively recreate experimental measurements of the decay rate of positronium in ethane and Argon. However, because density fluctuations are not included in DFT's the results show an unnatural discontinuity in decay rate plots. Because the PIMC technique is a microscopic model it includes density fluctuations and more closely resembles experimental measurements than DFT. The results of both approximations indicate that the

  11. High frequency flow-structural interaction in dense subsonic fluids

    NASA Technical Reports Server (NTRS)

    Liu, Baw-Lin; Ofarrell, J. M.

    1995-01-01

    Prediction of the detailed dynamic behavior in rocket propellant feed systems and engines and other such high-energy fluid systems requires precise analysis to assure structural performance. Designs sometimes require placement of bluff bodies in a flow passage. Additionally, there are flexibilities in ducts, liners, and piping systems. A design handbook and interactive data base have been developed for assessing flow/structural interactions to be used as a tool in design and development, to evaluate applicable geometries before problems develop, or to eliminate or minimize problems with existing hardware. This is a compilation of analytical/empirical data and techniques to evaluate detailed dynamic characteristics of both the fluid and structures. These techniques have direct applicability to rocket engine internal flow passages, hot gas drive systems, and vehicle propellant feed systems. Organization of the handbook is by basic geometries for estimating Strouhal numbers, added mass effects, mode shapes for various end constraints, critical onset flow conditions, and possible structural response amplitudes. Emphasis is on dense fluids and high structural loading potential for fatigue at low subsonic flow speeds where high-frequency excitations are possible. Avoidance and corrective measure illustrations are presented together with analytical curve fits for predictions compiled from a comprehensive data base.

  12. Shock-induced bubble jetting into a viscous fluid with application to tissue injury in shock-wave lithotripsy

    PubMed Central

    Freund, J. B.; Shukla, R. K.; Evan, A. P.

    2009-01-01

    Shock waves in liquids are known to cause spherical gas bubbles to rapidly collapse and form strong re-entrant jets in the direction of the propagating shock. The interaction of these jets with an adjacent viscous liquid is investigated using finite-volume simulation methods. This configuration serves as a model for tissue injury during shock-wave lithotripsy, a medical procedure to remove kidney stones. In this case, the viscous fluid provides a crude model for the tissue. It is found that for viscosities comparable to what might be expected in tissue, the jet that forms upon collapse of a small bubble fails to penetrate deeply into the viscous fluid “tissue.” A simple model reproduces the penetration distance versus viscosity observed in the simulations and leads to a phenomenological model for the spreading of injury with multiple shocks. For a reasonable selection of a single efficiency parameter, this model is able to reproduce in vivo observations of an apparent 1000-shock threshold before wide-spread tissue injury occurs in targeted kidneys and the approximate extent of this injury after a typical clinical dose of 2000 shock waves. PMID:19894850

  13. Minimal continuum theories of structure formation in dense active fluids

    NASA Astrophysics Data System (ADS)

    Dunkel, Jörn; Heidenreich, Sebastian; Bär, Markus; Goldstein, Raymond E.

    2013-04-01

    Self-sustained dynamical phases of living matter can exhibit remarkable similarities over a wide range of scales, from mesoscopic vortex structures in microbial suspensions and motility assays of biopolymers to turbulent large-scale instabilities in flocks of birds or schools of fish. Here, we argue that, in many cases, the phenomenology of such active states can be efficiently described in terms of fourth- and higher-order partial differential equations. Structural transitions in these models can be interpreted as Landau-type kinematic transitions in Fourier (wavenumber) space, suggesting that microscopically different biological systems can share universal long-wavelength features. This general idea is illustrated through numerical simulations for two classes of continuum models for incompressible active fluids: a Swift-Hohenberg-type scalar field theory, and a minimal vector model that extends the classical Toner-Tu theory and appears to be a promising candidate for the quantitative description of dense bacterial suspensions. We discuss how microscopic symmetry-breaking mechanisms can enter macroscopic continuum descriptions of collective microbial motion near surfaces, and conclude by outlining future applications.

  14. Halide based shock-wave treatment of fluid-rich natural phases

    NASA Astrophysics Data System (ADS)

    Schlothauer, T.; Schimpf, C.; Brendler, E.; Keller, K.; Kroke, E.; Heide, G.

    2015-11-01

    For the synthesis of high pressure phases from natural minerals and the shock wave treatment of fluid bearing phases a halide based method was developed. The experiments were performed in the pressure range between 25 and 162 GPa with a success rate for the new method of 100% for the new method. Based on the Impedance Corrected Sample Recovery Capsule under avoiding the adiabatic decompression a direct comparison between different loading paths and sample holder geometries is possible. The recovered samples show neither indications of melting in the case of kaolinite and very limited degassing in the case of carbonates. The recovery of amorphous water bearing Al-Si-phases with Aluminum in four-, five- and six-fold coordination was possible. The samples were analyzed with scanning electron microscopy, x-ray diffraction, nuclear-magnetic-resonance- and infra-red-spectroscopy and the results were directly compared.

  15. Transport theory for the Lennard-Jones dense fluid

    SciTech Connect

    Karkheck, J.; Stell, G.; Xu, J.

    1988-11-01

    A kinetic theory for a fluid of particles interacting via a pair potential with hard-core plus truncated tail is described and used to derive a transport theory for the Lennard-Jones fluid as well as the square-well fluid. Numerical results for shear viscosity, thermal conductivity, and the self-diffusion coefficient are given for the Lennard-Jones fluid and compared with simulation and experimental results. Our Lennard-Jones theory proves quantitatively useful over a wide range of states.

  16. Dynamics of dense granular flows of small-and-large-grain mixtures in an ambient fluid.

    PubMed

    Meruane, C; Tamburrino, A; Roche, O

    2012-08-01

    Dense grain flows in nature consist of a mixture of solid constituents that are immersed in an ambient fluid. In order to obtain a good representation of these flows, the interaction mechanisms between the different constituents of the mixture should be considered. In this article, we study the dynamics of a dense granular flow composed of a binary mixture of small and large grains immersed in an ambient fluid. In this context, we extend the two-phase approach proposed by Meruane et al. [J. Fluid Mech. 648, 381 (2010)] to the case of flowing dense binary mixtures of solid particles, by including in the momentum equations a constitutive relation that describes the interaction mechanisms between the solid constituents in a dense regime. These coupled equations are solved numerically and validated by comparing the numerical results with experimental measurements of the front speed of gravitational granular flows resulting from the collapse, in ambient air or water, of two-dimensional granular columns that consisted of mixtures of small and large spherical particles of equal mass density. Our results suggest that the model equations include the essential features that describe the dynamics of grains flows of binary mixtures in an ambient fluid. In particular, it is shown that segregation of small and large grains can increase the front speed because of the volumetric expansion of the flow. This increase in flow speed is damped by the interaction forces with the ambient fluid, and this behavior is more pronounced in water than in air.

  17. Dynamics of dense granular flows of small-and-large-grain mixtures in an ambient fluid.

    PubMed

    Meruane, C; Tamburrino, A; Roche, O

    2012-08-01

    Dense grain flows in nature consist of a mixture of solid constituents that are immersed in an ambient fluid. In order to obtain a good representation of these flows, the interaction mechanisms between the different constituents of the mixture should be considered. In this article, we study the dynamics of a dense granular flow composed of a binary mixture of small and large grains immersed in an ambient fluid. In this context, we extend the two-phase approach proposed by Meruane et al. [J. Fluid Mech. 648, 381 (2010)] to the case of flowing dense binary mixtures of solid particles, by including in the momentum equations a constitutive relation that describes the interaction mechanisms between the solid constituents in a dense regime. These coupled equations are solved numerically and validated by comparing the numerical results with experimental measurements of the front speed of gravitational granular flows resulting from the collapse, in ambient air or water, of two-dimensional granular columns that consisted of mixtures of small and large spherical particles of equal mass density. Our results suggest that the model equations include the essential features that describe the dynamics of grains flows of binary mixtures in an ambient fluid. In particular, it is shown that segregation of small and large grains can increase the front speed because of the volumetric expansion of the flow. This increase in flow speed is damped by the interaction forces with the ambient fluid, and this behavior is more pronounced in water than in air. PMID:23005858

  18. Coupled discrete element modeling of fluid injection into dense granular media

    NASA Astrophysics Data System (ADS)

    Zhang, Fengshou; Damjanac, Branko; Huang, Haiying

    2013-06-01

    The coupled displacement process of fluid injection into a dense granular medium is investigated numerically using a discrete element method (DEM) code PFC2D® coupled with a pore network fluid flow scheme. How a dense granular medium behaves in response to fluid injection is a subject of fundamental and applied research interests to better understand subsurface processes such as fluid or gas migration and formation of intrusive features as well as engineering applications such as hydraulic fracturing and geological storage in unconsolidated formations. The numerical analysis is performed with DEM executing the mechanical calculation and the network model solving the Hagen-Poiseuille equation between the pore spaces enclosed by chains of particles and contacts. Hydromechanical coupling is realized by data exchanging at predetermined time steps. The numerical results show that increase in the injection rate and the invading fluid viscosity and decrease in the modulus and permeability of the medium result in fluid flow behaviors displaying a transition from infiltration-governed to infiltration-limited and the granular medium responses evolving from that of a rigid porous medium to localized failure leading to the development of preferential paths. The transition in the fluid flow and granular medium behaviors is governed by the ratio between the characteristic times associated with fluid injection and hydromechanical coupling. The peak pressures at large injection rates when fluid leakoff is limited compare well with those from the injection experiments in triaxial cells in the literature. The numerical analysis also reveals intriguing tip kinematics field for the growth of a fluid channel, which may shed light on the occurrence of the apical inverted-conical features in sandstone and magma intrusion in unconsolidated formations.

  19. Hydrodynamics of fluid-solid coexistence in dense shear granular flow.

    PubMed

    Khain, Evgeniy

    2007-05-01

    We consider dense rapid shear flow of inelastically colliding hard disks. Navier-Stokes granular hydrodynamics is applied accounting for the recent finding that shear viscosity diverges at a lower density than the rest of the constitutive relations. New interpolation formulas for constitutive relations between dilute and dense cases are proposed and justified in molecular dynamics (MD) simulations. A linear stability analysis of the uniform shear flow is performed and the full phase diagram is presented. It is shown that when the inelasticity of particle collision becomes large enough, the uniform sheared flow gives way to a two-phase flow, where a dense "solidlike" striped cluster is surrounded by two fluid layers. The results of the analysis are verified in event-driven MD simulations, and a good agreement is observed.

  20. Shock waves and double layers in electron degenerate dense plasma with viscous ion fluids

    SciTech Connect

    Mamun, A. A.; Zobaer, M. S.

    2014-02-15

    The properties of ion-acoustic shock waves and double layers propagating in a viscous degenerate dense plasma (containing inertial viscous ion fluid, non-relativistic and ultra-relativistic degenerate electron fluid, and negatively charged stationary heavy element) is investigated. A new nonlinear equation (viz. Gardner equation with additional dissipative term) is derived by the reductive perturbation method. The properties of the ion-acoustic shock waves and double layers are examined by the analysis of the shock and double layer solutions of this new equation (we would like to call it “M-Z equation”). It is found that the properties of these shock and double layer structures obtained from this analysis are significantly different from those obtained from the analysis of standard Gardner or Burgers’ equation. The implications of our results to dense plasmas in astrophysical objects (e.g., non-rotating white dwarf stars) are briefly discussed.

  1. Rheology of dense suspensions of non colloidal spheres in yield-stress fluids

    NASA Astrophysics Data System (ADS)

    Guazzelli, Elisabeth; Dagois-Bohy, Simon; Hormozi, Sarah; Pouliquen, Olivier; Aix-Marseille Université, Cnrs, Iusti Umr 7343 Team; Department Of Mechanical Engineering, Ohio University Team

    2015-11-01

    Pressure-imposed rheometry is used to study the rheological properties of suspensions of non colloidal spheres in yield stress fluids. Accurate measurements for both the shear stress and particle normal stress are obtained in the dense regime. The rheological measurements are favourably compared to a model based on scaling arguments and homogenisation methods. The detailed account of this study can be found in. ANR-13-IS09-0005-01, Etudes et Productions Schlumberger, NSERC Postdoctoral Fellowships Program PDF-439036-2013.

  2. A consistent calculation of the chemical potential for dense simple fluids.

    PubMed

    Bomont, Jean-Marc

    2006-05-28

    A general method to calculate the excess chemical potential betamuex, that is based on the Kirkwood coupling parameter's dependence of the correlation functions, is presented. The expression for the one particle bridge function B(1)r is derived for simple fluids with spherical interactions. Only the knowledge of the bridge function B(2)r is required. The accuracy of our approach is illustrated for a dense hard sphere fluid. As far as B(2)r is considered as exact, B(1)r is found to be, at high densities, the normalized bridge function -B(2)rB(2)(r=0). This expression ensures a consistent calculation of the excess chemical potential by satisfying implicitly the Gibbs-Duhem constraint. Only the pressure-consistency condition is necessary to calculate the structural and thermodynamic properties of the fluid.

  3. Atomization and dense-fluid breakup regimes in liquid rocket engines

    SciTech Connect

    Oefelein, Joseph; Dahms, Rainer Norbert Uwe

    2015-04-20

    Until recently, modern theory has lacked a fundamentally based model to predict the operating pressures where classical sprays transition to dense-fluid mixing with diminished surface tension. In this paper, such a model is presented to quantify this transition for liquid-oxygen–hydrogen and n-decane–gaseous-oxygen injection processes. The analysis reveals that respective molecular interfaces break down not necessarily because of vanishing surface tension forces but instead because of the combination of broadened interfaces and a reduction in mean free molecular path. When this occurs, the interfacial structure itself enters the continuum regime, where transport processes rather than intermolecular forces dominate. Using this model, regime diagrams for the respective systems are constructed that show the range of operating pressures and temperatures where this transition occurs. The analysis also reveals the conditions where classical spray dynamics persists even at high supercritical pressures. As a result, it demonstrates that, depending on the composition and temperature of the injected fluids, the injection process can exhibit either classical spray atomization, dense-fluid diffusion-dominated mixing, or supercritical mixing phenomena at chamber pressures encountered in state-of-the-art liquid rocket engines.

  4. Atomization and dense-fluid breakup regimes in liquid rocket engines

    DOE PAGES

    Oefelein, Joseph; Dahms, Rainer Norbert Uwe

    2015-04-20

    Until recently, modern theory has lacked a fundamentally based model to predict the operating pressures where classical sprays transition to dense-fluid mixing with diminished surface tension. In this paper, such a model is presented to quantify this transition for liquid-oxygen–hydrogen and n-decane–gaseous-oxygen injection processes. The analysis reveals that respective molecular interfaces break down not necessarily because of vanishing surface tension forces but instead because of the combination of broadened interfaces and a reduction in mean free molecular path. When this occurs, the interfacial structure itself enters the continuum regime, where transport processes rather than intermolecular forces dominate. Using this model,more » regime diagrams for the respective systems are constructed that show the range of operating pressures and temperatures where this transition occurs. The analysis also reveals the conditions where classical spray dynamics persists even at high supercritical pressures. As a result, it demonstrates that, depending on the composition and temperature of the injected fluids, the injection process can exhibit either classical spray atomization, dense-fluid diffusion-dominated mixing, or supercritical mixing phenomena at chamber pressures encountered in state-of-the-art liquid rocket engines.« less

  5. Shockwave Consolidation of Nanostructured Thermoelectric Materials

    NASA Technical Reports Server (NTRS)

    Prasad, Narasimha S.; Taylor, Patrick; Nemir, David

    2014-01-01

    Nanotechnology based thermoelectric materials are considered attractive for developing highly efficient thermoelectric devices. Nano-structured thermoelectric materials are predicted to offer higher ZT over bulk materials by reducing thermal conductivity and increasing electrical conductivity. Consolidation of nano-structured powders into dense materials without losing nanostructure is essential towards practical device development. Using the gas atomization process, amorphous nano-structured powders were produced. Shockwave consolidation is accomplished by surrounding the nanopowder-containing tube with explosives and then detonating. The resulting shock wave causes rapid fusing of the powders without the melt and subsequent grain growth. We have been successful in generating consolidated nano-structured bismuth telluride alloy powders by using the shockwave technique. Using these consolidated materials, several types of thermoelectric power generating devices have been developed. Shockwave consolidation is anticipated to generate large quantities of nanostructred materials expeditiously and cost effectively. In this paper, the technique of shockwave consolidation will be presented followed by Seebeck Coefficient and thermal conductivity measurements of consolidated materials. Preliminary results indicate a substantial increase in electrical conductivity due to shockwave consolidation technique.

  6. A New Unsteady Model for Dense Cloud Cavitation in Cryogenic Fluids

    NASA Technical Reports Server (NTRS)

    Hosangadi, A.; Ahuja, V.

    2005-01-01

    A new unsteady, cavitation model is presented wherein the phase change process (bubble growth/collapse) is coupled to the acoustic field in a cryogenic fluid. It predicts the number density and radius of bubbles in vapor clouds by tracking both the aggregate surface area and volume fraction of the cloud. Hence, formulations for the dynamics of individual bubbles (e.g. Rayleigh-Plesset equation) may be integrated within the macroscopic context of a dense vapor cloud i.e. a cloud that occupies a significant fraction of available volume and contains numerous bubbles. This formulation has been implemented within the CRUNCH CFD, which has a compressible real fluid formulation, a multi-element, unstructured grid framework, and has been validated extensively for liquid rocket turbopump inducers. Detailed unsteady simulations of a cavitating ogive in liquid nitrogen are presented where time-averaged mean cavity pressure and temperature depressions due to cavitation are compared with experimental data. The model also provides the spatial and temporal history of the bubble size distribution in the vapor clouds that are shed, an important physical parameter that is difficult to measure experimentally and is a significant advancement in the modeling of dense cloud cavitation.

  7. The Chelyabinsk airburst shockwave

    NASA Astrophysics Data System (ADS)

    Popova, O.; Shuvalov, V.; Rybnov, Y.; Jenniskens, P.; Kharlamov, V.; Usoltseva, O.; Glazachev, D.; Podobnaya, E.; Dyagilev, R.; Trubetskaya, I.

    2014-07-01

    The Chelyabinsk airburst of 15 February 2013 was exceptional because of the large kinetic energy of the impacting body and because the airburst that was generated created significant damage and injuries in a densely populated area. The butterfly-shape of the damaged area (Popova et al., 2013) is explained from the fact that the energy was deposited over a range of altitudes. Some uncertainty remains about the source energy of the airburst, because it is not known precisely at what pressure glass is expected to break. Reasonable results were obtained for energies of 300--520 kt TNT and over pressures of 500--1000 Pa, assuming that the time dependence of the energy release followed the meteor lightcurve (Popova et al. 2013). Additional information about the airburst characteristics may be extracted from the arrival times of the shockwave at various locations and from pressure records. Arrival times of the shock wave were derived from video observations. From the analysis of these shock wave arrival times, a range of altitudes of energy deposition was derived (Popova et al. 2013). The observed arrival times were compared with model estimates, taking into account the real wind and atmospheric conditions. Results of the numerical simulations were compared with recorded sound signals, which were often quite complex. Borovicka et al. (2013) suggested that subsequent acoustic arrivals corresponded to separate fragmentation events. This hypothesis is tested. There were no instrumental records of overpressure in the damaged area. However, seismic records exist from locations surrounding a coal mine at Korkino, situated in the damage area close to the meteoroid trajectory, almost immediately below the region of highest energy deposition. Its seismic control system to monitor land slides recorded the blast wave from the meteoroid entry indirectly due to coupling to the ground. This is the only instrumental record of the airburst close to the meteoroid trajectory. An analysis

  8. Dynamic response and stability of a flapping foil in a dense and viscous fluid

    NASA Astrophysics Data System (ADS)

    Chae, Eun Jung; Akcabay, Deniz Tolga; Young, Yin Lu

    2013-10-01

    It is important to understand and accurately predict the static and dynamic response and stability of flexible hydro/aero lifting bodies to ensure their structural safety, to facilitate the design/optimization of new/existing concepts, and to test the feasibility of using advanced materials. The present study investigates the influence of solid-to-fluid added mass ratio (sqrt{μ _b}) and viscous effects on the fluid-structure interaction (FSI) response and stability of a flapping foil in incompressible and turbulent flows using a recently presented efficient and stable numerical algorithm in time-domain, which couples an unsteady Reynolds Average Navier-Stokes solver with a two degrees-of freedom structural model. The new numerical coupling method is able to stably and accurately simulate the FSI behavior of light foils in dense fluids: a limit which is known to be numerically difficult to study with classical FSI coupling methods. The studied FSI responses include static/dynamic divergence and flutter instabilities, which are compared with inviscid, linear potential theory predictions obtained with both time and frequency domain formulations, as well as with several published experimental data. In general, the results show that the critical reduced flutter velocities and reduced divergence velocities both decrease as sqrt{μ _b} decreases, and are captured with good accuracy using the viscous FSI solver for a wide range of relative mass ratios that are typical to air/hydrofoils. The comparative analyses showed that the classic frequency-domain linear potential theory is severely unconservative for predicting the flutter velocity for cases with sqrt{μ _b}<3: this includes the typical operating conditions of most marine and biomedical lifting devices, where the fluid forces are comparable to the solid forces, and strong nonlinear interactions may develop. In addition, the viscous FSI solver is shown to correctly predict the experimentally reported critical

  9. Numerical study of long-time dynamics and ergodic-nonergodic transitions in dense simple fluids

    NASA Astrophysics Data System (ADS)

    McCowan, David D.

    2015-08-01

    Since the mid-1980s, mode-coupling theory (MCT) has been the de facto theoretic description of dense fluids and the transition from the fluid state to the glassy state. MCT, however, is limited by the approximations used in its construction and lacks an unambiguous mechanism to institute corrections. We use recent results from a new theoretical framework—developed from first principles via a self-consistent perturbation expansion in terms of an effective two-body potential—to numerically explore the kinetics of systems of classical particles, specifically hard spheres governed by Smoluchowski dynamics. We present here a full solution for such a system to the kinetic equation governing the density-density time correlation function and show that the function exhibits the characteristic two-step decay of supercooled fluids and an ergodic-nonergodic transition to a dynamically arrested state. Unlike many previous numerical studies—and in stark contrast to experiment—we have access to the full time and wave-number range of the correlation function with great precision and are able to track the solution unprecedentedly close to the transition, covering nearly 15 decades in scaled time. Using asymptotic approximation techniques analogous to those developed for MCT, we fit the solution to predicted forms and extract critical parameters. We find complete qualitative agreement with known glassy behavior (e.g. power-law divergence of the α -relaxation time scale in the ergodic phase and square-root growth of the glass form factors in the nonergodic phase), as well as some limited quantitative agreement [e.g. the transition at packing fraction η*=0.60149761 (10 ) ] , consistent with previous static solutions under this theory and with comparable colloidal suspension experiments. However, most importantly, we establish that this new theory is able to reproduce the salient features seen in other theories, experiments, and simulations but has the advantages of being

  10. Quantum molecular dynamics study of expanded beryllium: Evolution from warm dense matter to atomic fluid

    PubMed Central

    Li, Dafang; Liu, Haitao; Zeng, Siliang; Wang, Cong; Wu, Zeqing; Zhang, Ping; Yan, Jun

    2014-01-01

    By performing quantum molecular dynamics (QMD) simulations, we investigate the equation of states, electrical and optical properties of the expanded beryllium at densities two to one-hundred lower than the normal solid density, and temperatures ranging from 5000 to 30000 K. With decreasing the density of Be, the optical response evolves from the one characteristic of a simple metal to the one of an atomic fluid. By fitting the optical conductivity spectra with the Drude-Smith model, it is found that the conducting electrons become localized at lower densities. In addition, the negative derivative of the electrical resistivity on temperature at density about eight lower than the normal solid density demonstrates that the metal to nonmetal transition takes place in the expanded Be. To interpret this transition, the electronic density of states is analyzed systematically. Furthermore, a direct comparison of the Rosseland opacity obtained by using QMD and the standard opacity code demonstrates that QMD provides a powerful tool to validate plasma models used in atomic physics approaches in the warm dense matter regime. PMID:25081816

  11. Modeling and simulation of dense cloud dispersion in urban areas by means of computational fluid dynamics.

    PubMed

    Scargiali, F; Grisafi, F; Busciglio, A; Brucato, A

    2011-12-15

    The formation of toxic heavy clouds as a result of sudden accidental releases from mobile containers, such as road tankers or railway tank cars, may occur inside urban areas so the problem arises of their consequences evaluation. Due to the semi-confined nature of the dispersion site simplified models may often be inappropriate. As an alternative, computational fluid dynamics (CFD) has the potential to provide realistic simulations even for geometrically complex scenarios since the heavy gas dispersion process is described by basic conservation equations with a reduced number of approximations. In the present work a commercial general purpose CFD code (CFX 4.4 by Ansys(®)) is employed for the simulation of dense cloud dispersion in urban areas. The simulation strategy proposed involves a stationary pre-release flow field simulation followed by a dynamic after-release flow and concentration field simulations. In order to try a generalization of results, the computational domain is modeled as a simple network of straight roads with regularly distributed blocks mimicking the buildings. Results show that the presence of buildings lower concentration maxima and enlarge the side spread of the cloud. Dispersion dynamics is also found to be strongly affected by the quantity of heavy-gas released.

  12. Tables of equation-of-state, thermodynamic properties, and shock Hugoniot for hot dense fluid deuterium

    SciTech Connect

    Zaghloul, Mofreh R.

    2015-11-15

    We present computational results and tables of the equation-of-state, thermodynamic properties, and shock Hugoniot for hot dense fluid deuterium. The present results are generated using a recently developed chemical model that takes into account different high density effects such as Coulomb interactions among charged particles, partial degeneracy, and intensive short range hard core repulsion. Internal partition functions are evaluated in a statistical-mechanically consistent way implementing recent developments in the literature. The shock Hugoniot curve derived from the present tables is overall in reasonable agreement with the Hugoniot derived from the Nova-laser shock wave experiments on liquid deuterium, showing that deuterium has a significantly higher compressibility than predicted by the SESAME tables or by Path Integral Monte Carlo calculations. Computational results are presented as surface plots for the dissociated fraction, degree of ionization, pressure, and specific internal energy for densities ranging from 0.0001 to 40 g/cm{sup 3} and temperatures from 2000 to ∼10{sup 6 }K. Tables for values of the above mentioned quantities in addition to the specific heat at constant pressure, c{sub p}, ratio of specific heats, c{sub p}/c{sub v}, sound speed and Hugoniot curve (for a specific initial state) are presented for practical use.

  13. Numerical study of long-time dynamics and ergodic-nonergodic transitions in dense simple fluids.

    PubMed

    McCowan, David D

    2015-08-01

    Since the mid-1980s, mode-coupling theory (MCT) has been the de facto theoretic description of dense fluids and the transition from the fluid state to the glassy state. MCT, however, is limited by the approximations used in its construction and lacks an unambiguous mechanism to institute corrections. We use recent results from a new theoretical framework--developed from first principles via a self-consistent perturbation expansion in terms of an effective two-body potential--to numerically explore the kinetics of systems of classical particles, specifically hard spheres governed by Smoluchowski dynamics. We present here a full solution for such a system to the kinetic equation governing the density-density time correlation function and show that the function exhibits the characteristic two-step decay of supercooled fluids and an ergodic-nonergodic transition to a dynamically arrested state. Unlike many previous numerical studies--and in stark contrast to experiment--we have access to the full time and wave-number range of the correlation function with great precision and are able to track the solution unprecedentedly close to the transition, covering nearly 15 decades in scaled time. Using asymptotic approximation techniques analogous to those developed for MCT, we fit the solution to predicted forms and extract critical parameters. We find complete qualitative agreement with known glassy behavior (e.g. power-law divergence of the α-relaxation time scale in the ergodic phase and square-root growth of the glass form factors in the nonergodic phase), as well as some limited quantitative agreement [e.g. the transition at packing fraction η*=0.60149761(10)], consistent with previous static solutions under this theory and with comparable colloidal suspension experiments. However, most importantly, we establish that this new theory is able to reproduce the salient features seen in other theories, experiments, and simulations but has the advantages of being derived from

  14. Stepwise shockwave velocity determinator

    NASA Technical Reports Server (NTRS)

    Roth, Timothy E.; Beeson, Harold

    1992-01-01

    To provide an uncomplicated and inexpensive method for measuring the far-field velocity of a surface shockwave produced by an explosion, a stepwise shockwave velocity determinator (SSVD) was developed. The velocity determinator is constructed of readily available materials and works on the principle of breaking discrete sensors composed of aluminum foil contacts. The discrete sensors have an average breaking threshold of approximately 7 kPa. An incremental output step of 250 mV is created with each foil contact breakage and is logged by analog-to-digital instrumentation. Velocity data obtained from the SSVD is within approximately 11 percent of the calculated surface shockwave velocity of a muzzle blast from a 30.06 rifle.

  15. Gallbladder stones: shockwave therapy.

    PubMed

    Sackmann, M

    1992-11-01

    Within the past 7 years, gallbladder lithotripsy by shockwaves has been proven to be a safe and effective non-invasive therapy for selected patients with gallstone disease. While regulatory decisions prevent shockwave therapy from being used more frequently in the USA, the number of patients treated in Europe and Asia is increasing constantly. At our institution, a relatively constant number of about 250 new patients per year have been treated since 1988 (Figure 4). About 20% of patients with gallstones are suitable for shockwave therapy according to present criteria. The rate of evacuation of all fragments is determined by the initial stone number and stone size, the success at stone fragmentation, adjuvant bile acid dissolution therapy, and gallbladder contractility. In contrast to laparoscopic cholecystectomy (Dubois et al, 1989; Perissat et al, 1989; Southern Surgeons Club, 1991), shockwave therapy does not require general anaesthesia. And in contrast to direct contact dissolution therapy of gallbladder stones using MTBE (Thistle et al, 1989), lithotripsy is non-invasive. In the majority of patients, complete fragment disappearance takes several months. Preliminary analyses of the cost-effectiveness of lithotripsy have revealed that lithotripsy, including retreatments and bile acid medication for recurrent stones, costs about as much as open cholecystectomy (Rothschild et al, 1990; Bass et al, 1991). The ideal patient for gallbladder lithotripsy has a single radiolucent stone < or = 20-25 mm in diameter in a functioning gallbladder (Figure 1). In patients with such stones, nearly all studies have confirmed a favourable outcome with rapid clearance of all fragments and a relatively low rate of stone recurrence. For carefully selected patients, extracorporeal shockwave lithotripsy is therefore an attractive non-invasive therapy.

  16. [Calcinosis cutis treatment with extracorporeal shockwave therapy].

    PubMed

    Jeppesen, Sune Møller; Yderstræde, Knud Bonnet; Lund, Lars

    2015-05-25

    Calcinosis cutis is a rare disease entity characterized by deposits of calcium in the skin and subcutaneous tissue causing hard-to-heal ulcers. This is a case report on a patient with femoral ulcers in connection with densely mineralized skin caused by ketobemidon injections. Next to surgical excision of calcified tissue the patient received extracorporeal shockwave therapy (ESWT). On the basis of excellent healing, partial skin transplant was feasible. We advocate for randomized trials on ESWT as an adjunctive therapy for complex non-healing wounds.

  17. Numerical Simulation of the Dynamic FSI Response and Stability of a Flapping Foil in a Dense Fluid

    NASA Astrophysics Data System (ADS)

    Chae, Eun Jung; Akcabay, Deniz Tolga; Young, Yin Lu

    2012-11-01

    To advance the understanding of fish locomotion, improve the design biological devices or marine propulsions or turbines, or to explore innovative ocean energy harvesting ideas, it is important to be able accurately predict the dynamic fluid structure interaction (FSI) response and stability of flexible structures in a dense fluid. The objectives of this research are to (1) present an efficient and stable algorithm for numerical modeling of the dynamic FSI response and stability of a flapping foil in dense fluid, and (2) investigate the influence of fluid-to-solid density ratio on the FSI response and stability of a flapping foil. The numerical model involves coupling an unsteady RANS solver with a 2DOF structural model using a new hybrid coupling approach. The results show that the new hybrid coupling approach converge much faster than traditional loosely and tightly coupled approaches, and is able to avoid numerical instability issues due to virtual added mass effects for light, flexible structures in incompressible flow. The influence of density ratio on the FSI response, divergence and flutter speeds are presented, along with comparisons between viscous and inviscid FSI computations.

  18. [Shockwave therapy of gallstones].

    PubMed

    Sackmann, M; Holl, J; Klüppelberg, U; von Ritter, C

    1993-09-01

    Extracorporeal shock-wave lithotripsy (ESWL) is a helpful adjunct for those bile duct stones which cannot be extracted by routine endoscopic measures including mechanical lithotripsy. For very large or impacted stones in the bile duct or stones in the intrahepatic biliary tree, and also for stones located in proximity to a bile duct stenosis, shock-wave therapy has proven to be safe and successful. More than 85% of the patients become free of stones after this therapy; they otherwise would have had to undergo high-risk open bile duct surgery. For gallbladder calculi, the pivotal factor for complete fragment disappearance after shock-wave therapy is sufficient stone disintegration. Only if fragments not larger than 3 mm are achieved, complete expulsion and/or dissolution of these fragments may be expected in a high percentage of the patients. Optimal candidates include patients with a single, radiolucent stone in a well-contracting gallbladder. For this group, ESWL is a safe and effective noninvasive therapeutic alternative.

  19. Shockwave lithotripsy: anecdotes and insights.

    PubMed

    Lingeman, James E; Kim, Samuel C; Kuo, Ramsay L; McAteer, James A; Evan, Andrew P

    2003-11-01

    Shockwave lithotripters have evolved considerably since the introduction of the Dornier HM3 machine 20 years ago. Although shockwave lithotripsy (SWL) remains the preferred treatment for the majority of symptomatic upper urinary-tract calculi, newer lithotripters are not as effective and may have a higher risk of side effects. Lack of progress in lithotripter evolution is attributable to inadequate understanding of how and why shockwaves produce effects on stone and tissue. Current knowledge suggests that stones fragment by the mechanisms of compression fracture, spallation, squeezing, and acoustic cavitation, while tissue damage from shockwaves is secondary to cavitation and non-cavitational forces such as sheer stress. It appears likely that most tissue damage from shockwaves is caused by cavitation. As the understanding of SWL matures, new lithotripter designs may emerge that truly represent an improvement on the original Dornier HM3 machine.

  20. Numerical Simulation of Low-Density Shock-Wave Interactions

    NASA Technical Reports Server (NTRS)

    Glass, Christopher E.

    1999-01-01

    Computational Fluid Dynamics (CFD) numerical simulations of low-density shock-wave interactions for an incident shock impinging on a cylinder have been performed. Flow-field density gradient and surface pressure and heating define the type of interference pattern and corresponding perturbations. The maximum pressure and heat transfer level and location for various interaction types (i.e., shock-wave incidence with respect to the cylinder) are presented. A time-accurate solution of the Type IV interference is employed to demonstrate the establishment and the steadiness of the low-density flow interaction.

  1. Measurements of Grain Motion in a Dense, Three-Dimensional Granular Fluid

    NASA Astrophysics Data System (ADS)

    Yang, Xiaoyu; Huan, Chao; Candela, D.; Mair, R. W.; Walsworth, R. L.

    2002-01-01

    We have used an NMR technique to measure the short-time, three-dimensional displacement of grains in a system of mustard seeds vibrated vertically at 15g. The technique averages over a time interval in which the grains move ballistically, giving a direct measurement of the granular temperature profile. The dense, lower portion of the sample is well described by a recent hydrodynamic theory for inelastic hard spheres. Near the free upper surface the mean free path is longer than the particle diameter and the hydrodynamic description fails.

  2. Measurements of Grain Motion in a Dense, Three-Dimensional Granular Fluid

    NASA Astrophysics Data System (ADS)

    Yang, Xiaoyu; Huan, Chao; Candela, D.; Mair, R. W.; Walsworth, R. L.

    2002-03-01

    We have used NMR to measure the short-time, three-dimensional displacement of grains in a system of mustard seeds vibrated vertically at 15g. The measurements are in the ballistic regime, giving direct access to the granular temperature profile. The data are compared to a recent hydrodynamic theory developed for high density granular flows. We find that the hydrodynamic theory works well for the dense, lower portion of the sample but breaks down near the free surface, where the mean free path becomes long.

  3. A two-phase solid/fluid model for dense granular flows including dilatancy effects

    NASA Astrophysics Data System (ADS)

    Mangeney, Anne; Bouchut, Francois; Fernandez-Nieto, Enrique; Koné, El-Hadj; Narbona-Reina, Gladys

    2016-04-01

    Describing grain/fluid interaction in debris flows models is still an open and challenging issue with key impact on hazard assessment [{Iverson et al.}, 2010]. We present here a two-phase two-thin-layer model for fluidized debris flows that takes into account dilatancy effects. It describes the velocity of both the solid and the fluid phases, the compression/dilatation of the granular media and its interaction with the pore fluid pressure [{Bouchut et al.}, 2016]. The model is derived from a 3D two-phase model proposed by {Jackson} [2000] based on the 4 equations of mass and momentum conservation within the two phases. This system has 5 unknowns: the solid and fluid velocities, the solid and fluid pressures and the solid volume fraction. As a result, an additional equation inside the mixture is necessary to close the system. Surprisingly, this issue is inadequately accounted for in the models that have been developed on the basis of Jackson's work [{Bouchut et al.}, 2015]. In particular, {Pitman and Le} [2005] replaced this closure simply by imposing an extra boundary condition at the surface of the flow. When making a shallow expansion, this condition can be considered as a closure condition. However, the corresponding model cannot account for a dissipative energy balance. We propose here an approach to correctly deal with the thermodynamics of Jackson's model by closing the mixture equations by a weak compressibility relation following {Roux and Radjai} [1998]. This relation implies that the occurrence of dilation or contraction of the granular material in the model depends on whether the solid volume fraction is respectively higher or lower than a critical value. When dilation occurs, the fluid is sucked into the granular material, the pore pressure decreases and the friction force on the granular phase increases. On the contrary, in the case of contraction, the fluid is expelled from the mixture, the pore pressure increases and the friction force diminishes. To

  4. Lubrication forces in dense granular flow with interstitial fluid: A simulation study with Discrete Element Method

    NASA Astrophysics Data System (ADS)

    Baran, Oleh; Ertas, Deniz; Halsey, Thomas; Zhou, Fuping

    2007-03-01

    Using three-dimensional molecular dynamics simulations, we study steady gravity-driven flows of frictional inelastic spheres of diameter d and density ρg down an incline, interacting through two-body lubrication forces in addition to granular contact forces. Scaling arguments suggest that, in 3D, these forces constitute the dominant perturbation of an interstitial fluid for small Reynolds number Re and low fluid densityρ. Two important parameters that characterize the strength of the lubrication forces are fluid viscosity and grain roughness. We observe that incline flows with lubrication forces exhibit a packing density that decreases with increasing distance from the surface. As the incline angle is increased, this results in a severely dilated basal layer that looks like ``hydroplaning'' similar to that observed in geological subaqueous debris flows. This is surprising since the model explicitly disallows any buildup of fluid pressure in the base of the flow, and suggests that hydroplaning might have other contributing factors besides this traditional explanation. The local packing density is still determined by the dimensionless strain rate I≡γ1ptd√ρg/p , where p is the average normal stress, obeying a ``dilatancy law'' similar to dry granular flows.

  5. A Two-Phase Solid/Fluid Model for Dense Granular Flows Including Dilatancy Effects

    NASA Astrophysics Data System (ADS)

    Mangeney, Anne; Bouchut, Francois; Fernandez-Nieto, Enrique; Narbona-Reina, Gladys

    2015-04-01

    We propose a thin layer depth-averaged two-phase model to describe solid-fluid mixtures such as debris flows. It describes the velocity of the two phases, the compression/dilatation of the granular media and its interaction with the pore fluid pressure, that itself modifies the friction within the granular phase (Iverson et al., 2010). The model is derived from a 3D two-phase model proposed by Jackson (2000) based on the 4 equations of mass and momentum conservation within the two phases. This system has 5 unknowns: the solid and fluid velocities, the solid and fluid pressures and the solid volume fraction. As a result, an additional equation inside the mixture is necessary to close the system. Surprisingly, this issue is inadequately accounted for in the models that have been developed on the basis of Jackson's work (Bouchut et al., 2014). In particular, Pitman and Le replaced this closure simply by imposing an extra boundary condition at the surface of the flow. When making a shallow expansion, this condition can be considered as a closure condition. However, the corresponding model cannot account for a dissipative energy balance. We propose here an approach to correctly deal with the thermodynamics of Jackson's equations. We close the mixture equations by a weak compressibility relation involving a critical density, or equivalently a critical pressure. Moreover, we relax one boundary condition, making it possible for the fluid to escape the granular media when compression of the granular mass occurs. Furthermore, we introduce second order terms in the equations making it possible to describe the evolution of the pore fluid pressure in response to the compression/dilatation of the granular mass without prescribing an extra ad-hoc equation for the pore pressure. We prove that the energy balance associated with this Jackson closure is dissipative, as well as its thin layer associated model. We present several numerical tests for the 1D case that are compared to the

  6. A Two-Phase Solid/Fluid Model for Dense Granular Flows Including Dilatancy Effects

    NASA Astrophysics Data System (ADS)

    Mangeney, A.; Bouchut, F.; Fernández-Nieto, E. D.; Narbona-Reina, G.; Kone, E. H.

    2014-12-01

    We propose a thin layer depth-averaged two-phase model to describe solid-fluid mixtures such as debris flows. It describes the velocity of the two phases, the compression/dilatation of the granular media and its interaction with the pore fluid pressure, that itself modifies the friction within the granular phase (Iverson et al., 2010). The model is derived from a 3D two-phase model proposed by Jackson (2000) based on the 4 equations of mass and momentum conservation within the two phases. This system has 5 unknowns: the solid and fluid velocities, the solid and fluid pressures and the solid volume fraction. As a result, an additional equation inside the mixture is necessary to close the system. Surprisingly, this issue is inadequately accounted for in the models that have been developed on the basis of Jackson's work (Bouchut et al., 2014). In particular, Pitman and Le replaced this closure simply by imposing an extra boundary condition at the surface of the flow. When making a shallow expansion, this condition can be considered as a closure condition. However, the corresponding model cannot account for a dissipative energy balance. We propose here an approach to correctly deal with the thermodynamics of Jackson's equations. We close the mixture equations by a weak compressibility relation involving a critical density, or equivalently a critical pressure. Moreover, we relax one boundary condition, making it possible for the fluid to escape the granular media when compression of the granular mass occurs. Furthermore, we introduce second order terms in the equations making it possible to describe the evolution of the pore fluid pressure in response to the compression/dilatation of the granular mass without prescribing an extra ad-hoc equation for the pore pressure. We prove that the energy balance associated with this Jackson closure is dissipative, as well as its thin layer associated model. We present several numerical tests for the 1D case that are compared to the

  7. Dynamic compression of dense oxide (Gd3Ga5O12) from 0.4 to 2.6 TPa: Universal Hugoniot of fluid metals

    PubMed Central

    Ozaki, N.; Nellis, W. J.; Mashimo, T.; Ramzan, M.; Ahuja, R.; Kaewmaraya, T.; Kimura, T.; Knudson, M.; Miyanishi, K.; Sakawa, Y.; Sano, T.; Kodama, R.

    2016-01-01

    Materials at high pressures and temperatures are of great current interest for warm dense matter physics, planetary sciences, and inertial fusion energy research. Shock-compression equation-of-state data and optical reflectivities of the fluid dense oxide, Gd3Ga5O12 (GGG), were measured at extremely high pressures up to 2.6 TPa (26 Mbar) generated by high-power laser irradiation and magnetically-driven hypervelocity impacts. Above 0.75 TPa, the GGG Hugoniot data approach/reach a universal linear line of fluid metals, and the optical reflectivity most likely reaches a constant value indicating that GGG undergoes a crossover from fluid semiconductor to poor metal with minimum metallic conductivity (MMC). These results suggest that most fluid compounds, e.g., strong planetary oxides, reach a common state on the universal Hugoniot of fluid metals (UHFM) with MMC at sufficiently extreme pressures and temperatures. The systematic behaviors of warm dense fluid would be useful benchmarks for developing theoretical equation-of-state and transport models in the warm dense matter regime in determining computational predictions. PMID:27193942

  8. Dynamic compression of dense oxide (Gd3Ga5O12) from 0.4 to 2.6 TPa: Universal Hugoniot of fluid metals.

    PubMed

    Ozaki, N; Nellis, W J; Mashimo, T; Ramzan, M; Ahuja, R; Kaewmaraya, T; Kimura, T; Knudson, M; Miyanishi, K; Sakawa, Y; Sano, T; Kodama, R

    2016-01-01

    Materials at high pressures and temperatures are of great current interest for warm dense matter physics, planetary sciences, and inertial fusion energy research. Shock-compression equation-of-state data and optical reflectivities of the fluid dense oxide, Gd3Ga5O12 (GGG), were measured at extremely high pressures up to 2.6 TPa (26 Mbar) generated by high-power laser irradiation and magnetically-driven hypervelocity impacts. Above 0.75 TPa, the GGG Hugoniot data approach/reach a universal linear line of fluid metals, and the optical reflectivity most likely reaches a constant value indicating that GGG undergoes a crossover from fluid semiconductor to poor metal with minimum metallic conductivity (MMC). These results suggest that most fluid compounds, e.g., strong planetary oxides, reach a common state on the universal Hugoniot of fluid metals (UHFM) with MMC at sufficiently extreme pressures and temperatures. The systematic behaviors of warm dense fluid would be useful benchmarks for developing theoretical equation-of-state and transport models in the warm dense matter regime in determining computational predictions. PMID:27193942

  9. Dynamic compression of dense oxide (Gd3Ga5O12) from 0.4 to 2.6 TPa: Universal Hugoniot of fluid metals

    NASA Astrophysics Data System (ADS)

    Ozaki, N.; Nellis, W. J.; Mashimo, T.; Ramzan, M.; Ahuja, R.; Kaewmaraya, T.; Kimura, T.; Knudson, M.; Miyanishi, K.; Sakawa, Y.; Sano, T.; Kodama, R.

    2016-05-01

    Materials at high pressures and temperatures are of great current interest for warm dense matter physics, planetary sciences, and inertial fusion energy research. Shock-compression equation-of-state data and optical reflectivities of the fluid dense oxide, Gd3Ga5O12 (GGG), were measured at extremely high pressures up to 2.6 TPa (26 Mbar) generated by high-power laser irradiation and magnetically-driven hypervelocity impacts. Above 0.75 TPa, the GGG Hugoniot data approach/reach a universal linear line of fluid metals, and the optical reflectivity most likely reaches a constant value indicating that GGG undergoes a crossover from fluid semiconductor to poor metal with minimum metallic conductivity (MMC). These results suggest that most fluid compounds, e.g., strong planetary oxides, reach a common state on the universal Hugoniot of fluid metals (UHFM) with MMC at sufficiently extreme pressures and temperatures. The systematic behaviors of warm dense fluid would be useful benchmarks for developing theoretical equation-of-state and transport models in the warm dense matter regime in determining computational predictions.

  10. Dynamic compression of dense oxide (Gd3Ga5O12) from 0.4 to 2.6 TPa: Universal Hugoniot of fluid metals

    DOE PAGES

    Ozaki, N.; Nellis, W. J.; Mashimo, T.; Ramzan, M.; Ahuja, R.; Kaewmaraya, T.; Kimura, T.; Knudson, M.; Miyanishi, K.; Sakawa, Y.; et al

    2016-05-19

    Materials at high pressures and temperatures are of great current interest for warm dense matter physics, planetary sciences, and inertial fusion energy research. Shock-compression equation-of-state data and optical reflectivities of the fluid dense oxide, Gd3Ga5O12 (GGG), were measured at extremely high pressures up to 2.6 TPa (26 Mbar) generated by high-power laser irradiation and magnetically-driven hypervelocity impacts. Above 0.75 TPa, the GGG Hugoniot data approach/reach a universal linear line of fluid metals, and the optical reflectivity most likely reaches a constant value indicating that GGG undergoes a crossover from fluid semiconductor to poor metal with minimum metallic conductivity (MMC). Thesemore » results suggest that most fluid compounds, e.g., strong planetary oxides, reach a common state on the universal Hugoniot of fluid metals (UHFM) with MMC at sufficiently extreme pressures and temperatures. Lastly, the systematic behaviors of warm dense fluid would be useful benchmarks for developing theoretical equation-of-state and transport models in the warm dense matter regime in determining computational predictions.« less

  11. [Shockwave lithotripsy in sialolithiasis patients].

    PubMed

    Abdusalamov, M R; Afanas'ev, V V; Gamataev, I I

    2014-01-01

    Shockwave lithotripsy was performed by various appliances in sialolithiasis patients. The best results were obtained by means of miniature appliances. Lithotripsy proved to be useful safe alternative for sialolithiasis treatment.

  12. On axial temperature gradients due to large pressure drops in dense fluid chromatography.

    PubMed

    Colgate, Sam O; Berger, Terry A

    2015-03-13

    The effect of energy degradation (Degradation is the creation of net entropy resulting from irreversibility.) accompanying pressure drops across chromatographic columns is examined with regard to explaining axial temperature gradients in both high performance liquid chromatography (HPLC) and supercritical fluid chromatography (SFC). The observed effects of warming and cooling can be explained equally well in the language of thermodynamics or fluid dynamics. The necessary equivalence of these treatments is reviewed here to show the legitimacy of using whichever one supports the simpler determination of features of interest. The determination of temperature profiles in columns by direct application of the laws of thermodynamics is somewhat simpler than applying them indirectly by solving the Navier-Stokes (NS) equations. Both disciplines show that the preferred strategy for minimizing the reduction in peak quality caused by temperature gradients is to operate columns as nearly adiabatically as possible (i.e. as Joule-Thomson expansions). This useful fact, however, is not widely familiar or appreciated in the chromatography community due to some misunderstanding of the meaning of certain terms and expressions used in these disciplines. In fluid dynamics, the terms "resistive heating" or "frictional heating" have been widely used as synonyms for the dissipation function, Φ, in the NS energy equation. These terms have been widely used by chromatographers as well, but often misinterpreted as due to friction between the mobile phase and the column packing, when in fact Φ describes the increase in entropy of the system (dissipation, ∫TdSuniv>0) due to the irreversible decompression of the mobile phase. Two distinctly different contributions to the irreversibility are identified; (1) ΔSext, viscous dissipation of work done by the external surroundings driving the flow (the pump) contributing to its warming, and (2) ΔSint, entropy change accompanying decompression of

  13. Mobile extracorporeal shockwave lithotripsy.

    PubMed

    Rajagopal, V; Bailey, M J

    1991-01-01

    During the last 18 months, extracorporeal shockwave lithotripsy (ESWL) has been provided at Epsom District Hospital using a mobile unit containing a Dornier HM4 lithotriptor. Patients with upper ureteric and renal stones were selected for treatment, which was performed without anaesthesia or sedation as a day-case procedure; 83 patients were treated, 5 of them with bilateral stones. Seventy patients required 1 treatment session, 17 required 2 and 1 patient required 3. There were no serious complications but 3 patients needed ureteroscopy to remove obstructing stones. The overall success rate was 86%. The cost to treat each NHS patient was 253 pounds. Mobile lithotripsy as a day-case procedure is a safe and cost-effective means of treating urolithiasis and can be performed in a District General Hospital.

  14. Quantum fluid model of coherent stimulated radiation by a dense relativistic cold electron beam

    SciTech Connect

    Monteiro, L. F.; Serbeto, A.; Tsui, K. H.; Mendonça, J. T.; Galvão, R. M. O.

    2013-07-15

    Using a quantum fluid model, the linear dispersion relation for FEL pumped by a short wavelength laser wiggler is deduced. Subsequently, a new quantum corrected resonance condition is obtained. It is shown that, in the limit of low energy electron beam and low frequency pump, the quantum recoil effect can be neglected, recovering the classical FEL resonance condition, k{sub s}=4k{sub w}γ{sup 2}. On the other hand, for short wavelength and high energy electron beam, the quantum recoil effect becomes strong and the resonance condition turns into k{sub s}=2√(k{sub w}/λ{sub c})γ{sup 3/2}, with λ{sub c} being the reduced Compton wavelength. As a result, a set of nonlinear coupled equations, which describes the quantum FEL dynamics as a three-wave interaction, is obtained. Neglecting wave propagation effects, this set of equations is solved numerically and results are presented.

  15. Thermodynamics and phase separation of dense fully-ionized hydrogen-helium fluid mixtures

    NASA Technical Reports Server (NTRS)

    Stevenson, D. J.

    1975-01-01

    The free energy of a hydrogen-helium fluid mixture is evaluated for the temperatures and densities appropriate to the deep interior of a giant planet such as Jupiter. The electrons are assumed to be fully pressure-ionized and degenerate. In this regime, an appropriate first approximation to the ionic distribution functions can be found by assuming hard sphere interactions. Corrections to this approximation are incorporated by means of the perturbation theory of Anderson and Chandler. Approximations for the three-body interactions and the nonlinear response of the electron gas to the ions are included. It is predicted that a hydrogen-helium mixture, containing 10% by number of helium ions, separates into hydrogen-rich and helium-rich phases below about 8000 K, at the pressures relevant to Jupiter (4-40 Megabars). It is also predicted that the alloy occupies less volume per ion than the separated phases. The equations of state and other thermodynamic derivatives are tabulated. Implications of these results are discussed.

  16. A Supernova's Shockwaves

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Supernovae are the explosive deaths of the universe's most massive stars. In death, these volatile creatures blast tons of energetic waves into the cosmos, destroying much of the dust surrounding them.

    This false-color composite from NASA's Spitzer Space Telescope and NASA's Chandra X-ray Observatory shows the remnant of one such explosion. The remnant, called N132D, is the wispy pink shell of gas at the center of this image. The pinkish color reveals a clash between the explosion's high-energy shockwaves and surrounding dust grains.

    In the background, small organic molecules called polycyclic aromatic hydrocarbons are shown as tints of green. The blue spots represent stars in our galaxy along this line of sight.

    N132D is located 163,000 light-years away in a neighboring galaxy called, the Large Magellanic Cloud.

    In this image, infrared light at 4.5 microns is mapped to blue, 8.0 microns to green and 24 microns to red. Broadband X-ray light is mapped purple. The infrared data were taken by Spitzer's infrared array camera and multiband imaging photometer, while the X-ray data were captured by Chandra.

  17. Temperature dependence of the liquid structure factor of dense monatomic fluids in the long wavelength limit in relation to thermal expansivity

    NASA Astrophysics Data System (ADS)

    March, N. H.; Alonso, J. A.

    2012-03-01

    The temperature dependence of the liquid structure factor S(k) of dense monatomic fluids, and especially a variety of liquid metals, is studied by combining thermodynamics and fluctuation theory in the long wavelength limit k → 0. Emphasis is placed on the connection of ? with thermal expansivity. Reference here is then made to recent semiempirical work of Lawson, who advocated an approximate relation, but at the melting temperature T m , between ? and the Gruneisen constant.

  18. Can Shockwave Therapy Improve Tendon Metabolism?

    PubMed

    Zwerver, Johannes; Waugh, Charlotte; van der Worp, Henk; Scott, Alex

    2016-01-01

    Shockwave treatments are commonly used in the management of tendon injuries and there is increasing evidence for its clinical effectiveness. There is a paucity of fundamental (in vivo) studies investigating the biological action of shockwave therapy. Destruction of calcifications, pain relief and mechanotransduction-initiated tissue regeneration and remodeling of the tendon are considered to be the most important working mechanisms. The heterogeneity of systems (focussed shockwave therapy vs. radial pressurewave therapy), treatment protocols and study populations, and the fact that there seem to be responders and non-responders, continue to make it difficult to give firm recommendations with regard to the most optimal shockwave therapy approach. Specific knowledge with regard to the effects of shockwave therapy in patients with metabolic tendon disorders is not available. Further fundamental and clinical research is required to determine the value of shockwave therapy in the management of tendinopathy.

  19. Can Shockwave Therapy Improve Tendon Metabolism?

    PubMed

    Zwerver, Johannes; Waugh, Charlotte; van der Worp, Henk; Scott, Alex

    2016-01-01

    Shockwave treatments are commonly used in the management of tendon injuries and there is increasing evidence for its clinical effectiveness. There is a paucity of fundamental (in vivo) studies investigating the biological action of shockwave therapy. Destruction of calcifications, pain relief and mechanotransduction-initiated tissue regeneration and remodeling of the tendon are considered to be the most important working mechanisms. The heterogeneity of systems (focussed shockwave therapy vs. radial pressurewave therapy), treatment protocols and study populations, and the fact that there seem to be responders and non-responders, continue to make it difficult to give firm recommendations with regard to the most optimal shockwave therapy approach. Specific knowledge with regard to the effects of shockwave therapy in patients with metabolic tendon disorders is not available. Further fundamental and clinical research is required to determine the value of shockwave therapy in the management of tendinopathy. PMID:27535269

  20. The Influence of Shockwave Therapy on Orthodontic Tooth Movement Induced in the Rat.

    PubMed

    Hazan-Molina, Hagai; Aizenbud, Itay; Kaufman, Hana; Teich, Sorin; Aizenbud, Dror

    2016-01-01

    Shockwave therapy is used in medicine due to its ability to stimulate healing processes. The application of orthodontic force evokes an inflammatory reaction resulting in tooth movement. Shockwave therapy might have an effect on both inflammatory and periodonal ligament cytokine profiles. Our aim was to evaluate the fluctuations of different inflammatory cytokines after orthodontic force induction with and without shockwave therapy. An orthodontic appliance was applied between the rats' molars and incisors. In conjunction with the commencement of orthodontic force, the rats were treated with a single episode of 1000 shock waves and the gingival crevicular fluid was collected for 3 days. The expression and concentration of different cytokines was evaluated by a commercial 4-multiplex fluorescent bead-based immunoassay. The level of all cytokines displayed a similar trend in both shockwave-treated and untreated groups; the concentration peaked on the first day and declined thereafter. In all cases, however, the cytokine levels were smaller in the shockwave-treated than in untreated animals; a significant difference was found for sRANKL and borderline difference for IL-6 on Day 1. We conclude that shockwave therapy during the induction of orthodontic tooth movement influences the expression of inflammatory cytokines.

  1. Extracorporeal shockwave lithotripsy in pediatrics.

    PubMed

    D'Addessi, Alessandro; Bongiovanni, Luca; Sasso, Francesco; Gulino, Gaetano; Falabella, Roberto; Bassi, Pierfrancesco

    2008-01-01

    Since its introduction in 1980, extracorporeal shockwave lithotripsy (SWL) has become the first therapeutic option in most cases of upper-tract urolithiasis, and the technique has been used for pediatric renal stones since the first report of success in 1986. Lithotripter effectiveness depends on the power expressed at the focal point. Closely correlated with the power is the pain produced by the shockwaves. By reducing the dimensions of the focus, it becomes possible to treat the patient without anesthesia or analgesia but at the cost of a higher re-treatment rate. Older children often tolerate SWL under intravenous sedation, and minimal anesthesia is applicable for most patients treated with second- and third-generation lithotripters. Ureteral stenting before SWL has been controversial. Current data suggest that preoperative stent placement should be reserved for a few specific cases. Stone-free rates in pediatric SWL exceed 70% at 3 months, with the rate reaching 100% in many series. Even the low-birth-weight infant can be treated with a stone-free as high as 100%. How can one explain the good results? Possible explanations include the lesser length of the child's ureter, which partially compensates for the narrower lumen. Moreover, the pediatric ureter is more elastic and distensible, which facilitates passage of stone fragments and prevents impaction. Another factor is shockwave reproduction in the body: there is a 10% to 20% damping of shockwave energy as it travels through 6 cm of body tissue, so the small body volume of the child allows the shockwaves to be transmitted with little loss of energy. There are several concerns regarding the possible detrimental effect of shockwaves on growing kidneys. Various renal injures have been documented with all type of lithotripters. On the other hand, several studies have not shown adverse effects. In general, SWL is considered to be the method of choice for managing the majority of urinary stones in children of all

  2. [Extracorporeal shockwave lithotripsy of bile duct calculi].

    PubMed

    Greiner, L; Jakobeit, C

    1993-08-01

    Shockwave therapy of bile duct stones is not dependent on difficult preconditions concerning stone-volume and -composition or subsequent lythic therapy. Its main indication is failure of endoscopic sphincterotomy (EST). Shockwave lithotripsy of bile duct stones--which may even be carried out even instead of EST in specific cases--is with a success rate of 80 to 95% as effective as shockwave lithotripsy in urology.

  3. Well-posed two-temperature constitutive equations for stable dense fluid shock waves using molecular dynamics and generalizations of Navier-Stokes-Fourier continuum mechanics.

    PubMed

    Hoover, Wm G; Hoover, Carol G

    2010-04-01

    Guided by molecular dynamics simulations, we generalize the Navier-Stokes-Fourier constitutive equations and the continuum motion equations to include both transverse and longitudinal temperatures. To do so we partition the contributions of the heat transfer, the work done, and the heat flux vector between the longitudinal and transverse temperatures. With shockwave boundary conditions time-dependent solutions of these equations converge to give stationary shockwave profiles. The profiles include anisotropic temperature and can be fitted to molecular dynamics results, demonstrating the utility and simplicity of a two-temperature description of far-from-equilibrium states.

  4. Extracorporeal shockwave therapy: a review.

    PubMed

    Chung, Bryan; Wiley, J Preston

    2002-01-01

    Extracorporeal shockwave therapy (ESWT) has been in use for the treatment of tendinopathies since the early 1990s. The exact mechanism by which ESWT relieves tendon-associated pain is not known; however, there is an increasing body of literature that suggests that it can be an effective therapy for patients who have had repeated nonsurgical treatment failures. The highest strength of evidence is shown in randomised controlled trials, of which there are a small number. Reported results for tendinopathies of the shoulder, elbow and heel have shown consistent positive results in favour of ESWT over placebo ESWT in individuals who have failed conservative therapy. These studies provide strong evidence for ESWT as an effective therapy for the treatment of chronic treatment-resistant tendinopathies. There is still much debate over several issues surrounding ESWT that have not been adequately addressed by the literature: high- versus low-energy ESWT, shockwave dosage and number of sessions required for a therapeutic effect. Further research is needed to ascertain the most beneficial protocol for patient care.

  5. Transport properties of dense fluid mixtures using nonequilibrium molecular dynamics. Final report, September 15, 1987--March 14, 1997

    SciTech Connect

    Murad, S.

    1997-05-01

    Computer Simulation Studies were carried out using the method of equilibrium and nonequilibrium molecular dynamics (NEMD) to examine a wide range of transport processes in both fluids and fluid mixtures. This included testing a wide range of mixing rules for thermal conductivity and viscosity. In addition a method was developed to calculate the internal rotational contributions to thermal conductivity and the accuracy of current methods for predicting these contributions were examined. These comparisons were then used to suggest possible ways of improving these theories. The method of NEMD was also used to examine the critical enhancements of thermal conductivity. Finally, molecular simulations were carried out to study the various transport coefficients of fluids confined by membranes, as well as important transport processes such as osmosis, and reverse osmosis.

  6. Theory of nonlinear elasticity, stress-induced relaxation, and dynamic yielding in dense fluids of hard nonspherical colloids.

    PubMed

    Zhang, Rui; Schweizer, Kenneth S

    2012-04-21

    We generalize the microscopic naïve mode coupling and nonlinear Langevin equation theories of the coupled translation-rotation dynamics of dense suspensions of uniaxial colloids to treat the effect of applied stress on shear elasticity, cooperative cage escape, structural relaxation, and dynamic and static yielding. The key concept is a stress-dependent dynamic free energy surface that quantifies the center-of-mass force and torque on a moving colloid. The consequences of variable particle aspect ratio and volume fraction, and the role of plastic versus double glasses, are established in the context of dense, glass-forming suspensions of hard-core dicolloids. For low aspect ratios, the theory provides a microscopic basis for the recently observed phenomenon of double yielding as a consequence of stress-driven sequential unlocking of caging constraints via reduction of the distinct entropic barriers associated with the rotational and translational degrees of freedom. The existence, and breadth in volume fraction, of the double yielding phenomena is predicted to generally depend on both the degree of particle anisotropy and experimental probing frequency, and as a consequence typically occurs only over a window of (high) volume fractions where there is strong decoupling of rotational and translational activated relaxation. At high enough concentrations, a return to single yielding is predicted. For large aspect ratio dicolloids, rotation and translation are always strongly coupled in the activated barrier hopping event, and hence for all stresses only a single yielding process is predicted.

  7. Extracorporeal shockwave lithotripsy of primary intrahepatic stones.

    PubMed

    Kim, M H; Lee, S K; Min, Y I; Lee, M G; Sung, K B; Cho, K S; Lee, S G; Min, P C

    1992-01-01

    Extracorporeal shockwave lithothripsy (ESWL) was performed in intrahepatic stone patients (n = 18) by Dornier MPL 9,000 with ultrasound guidance. The patients had T-tube (n = 9) or percutaneous transhepatic biliary drainage tube (n = 9). Average treatment session was four and shock-wave numbers were in the range of 3,064 to 12,000 (average 6,288 shocks). Intrahepatic stones were removed completely in 16 patients over a 3 month period by ESWL and combined stone extraction maneuver such as cholangioscopic or interventional radiologic method. Extracorporeal shockwave lithothripsy was very helpful in facilitating extraction of stones in unfavorable locations or located above the severe stricture. In summary, extracorporeal shockwave lithotripsy, followed by percutaneous stone extraction, will provide an improvement in the success rate and duration of treatment required for complete removal of primary hepatolithiasis.

  8. Shockwave Engine: Wave Disk Engine

    SciTech Connect

    2010-01-14

    Broad Funding Opportunity Announcement Project: MSU is developing a new engine for use in hybrid automobiles that could significantly reduce fuel waste and improve engine efficiency. In a traditional internal combustion engine, air and fuel are ignited, creating high-temperature and high-pressure gases which expand rapidly. This expansion of gases forces the engine’s pistons to pump and powers the car. MSU’s engine has no pistons. It uses the combustion of air and fuel to build up pressure within the engine, generating a shockwave that blasts hot gas exhaust into the blades of the engine’s rotors causing them to turn, which generates electricity. MSU’s redesigned engine would be the size of a cooking pot and contain fewer moving parts—reducing the weight of the engine by 30%. It would also enable a vehicle that could use 60% of its fuel for propulsion.

  9. On-sun first operation of a 150 kWth pilot solar receiver using dense particle suspension as heat transfer fluid

    NASA Astrophysics Data System (ADS)

    López, Inmaculada Pérez; Benoit, Hadrien; Gauthier, Daniel; Sans, Jean-Louis; Guillot, Emmanuel; Cavaillé, Roland; Mazza, German; Flamant, Gilles

    2016-05-01

    A 50-150 kWth pilot solar rig comprising the key equipments of a real plant and that uses silicon carbide Dense Particles Suspension as the heat transfer fluid has been tested at the 1 MW solar furnace at Odeillo-Font Romeu, France. The tests were carried out under large ranges of operating parameters and controlling the mass flow rate when higher temperature was required and when changes on DNI (direct normal irradiation) occurred. This paper presents experimental results on particle outlet temperature, dynamic response of the system to solid mass flow rate and solar power variations, and receiver thermal efficiency (η). Mean and maximum particles' temperature up to 585°C and 720°C respectively was reached. The receiver thermal efficiency was measured in the range 50-90%.

  10. Is extracorporeal shockwave lithotripsy suitable treatment for lower ureteric stones?

    PubMed

    Cole, R S; Shuttleworth, K E

    1988-12-01

    Forty patients with lower ureteric calculi for which intervention was considered desirable have been treated by in situ extracorporeal shockwave lithotripsy (ESWL) on the Dornier HM3 Lithotripter using a modified technique. Stone localisation was satisfactory in all patients. Adequate disintegration was achieved in 90% of patients following one treatment; 34 patients have been followed up for at least 3 months and 27 of these are stone-free (79%). Treatment failed in 4 patients and 2 of these had dense lower ureteric stone streets as a result of previous ESWL. The retreatment rate, post-treatment auxiliary procedure rate and complication rate were minimal. It was concluded that in situ ESWL is an effective and safe method for treating certain selected lower ureteric stones and should be considered as a feasible alternative to the more conventional methods of treatment.

  11. Cavitation in ultrasound and shockwave therapy

    NASA Astrophysics Data System (ADS)

    Colonius, Tim

    2014-11-01

    Acoustic waves, especially high-intensity ultrasound and shock waves, are used for medical imaging and intra- and extra-corporeal manipulation of cells, tissue, and urinary calculi. Waves are currently used to treat kidney stone disease, plantar fasciitis, and bone nonunion, and they are being investigated as a technique to ablate cancer tumors and mediate drug delivery. In many applications, acoustic waves induce the expansion and collapse of preexisting or newly cavitating bubbles whose presence can either mediate the generation of localized stresses or lead to collateral damage, depending on how effectively they can be controlled. We describe efforts aimed at simulating the collapse of bubbles, both individually and in clusters, with the aim to characterize the induced mechanical stresses and strains. To simulate collapse of one or a few bubbles, compressible Euler and Navier-Stokes simulations of multi-component materials are performed with WENO-based shock and interface capturing schemes. Repetitive insonification generates numerous bubbles that are difficult to resolve numerically. Such clouds are also important in traditional engineering applications such as caveating hydrofoils. Models that incorporate the dynamics of an unresolved dispersed phase consisting of the bubble cloud are also developed. The results of several model problems including bubble collapse near rigid surfaces, bubble collapse near compliant surfaces and in small capillaries are analyzed. The results are processed to determine the potential for micron-sized preexisting gas bubbles to damage capillaries. The translation of the fundamental fluid dynamics into improvements in the design and clinical application of shockwave lithotripters will be discussed. NIH Grant PO1-DK043881.

  12. [Conservative treatment of severe renal trauma after extracorporeal shockwave lithotripsy].

    PubMed

    Marchini, Giovanni Scala; Lopes, Roberto Iglesias; Bruschini, Homero; Torricelli, Fábio; Lopes, Roberto Nicomedes

    2011-01-01

    Subcapsular and perinephric hematomas are relatively common after shock-wave lithotripsy, but high-grade kidney injuries are extremely rare. We present the first case of a high-grade kidney injury after shock-wave lithotripsy managed conservatively. A 57-year-old white female patient with left 1.5cm superior ureteral calculi was submitted to shock-wave lithotripsy.

  13. Extracorporeal shockwave therapy in musculoskeletal disorders.

    PubMed

    Wang, Ching-Jen

    2012-01-01

    The sources of shockwave generation include electrohydraulic, electromagnetic and piezoelectric principles. Electrohydraulic shockwaves are high-energy acoustic waves generated under water explosion with high voltage electrode. Shockwave in urology (lithotripsy) is primarily used to disintegrate urolithiasis, whereas shockwave in orthopedics (orthotripsy) is not used to disintegrate tissues, rather to induce tissue repair and regeneration. The application of extracorporeal shockwave therapy (ESWT) in musculoskeletal disorders has been around for more than a decade and is primarily used in the treatment of sports related over-use tendinopathies such as proximal plantar fasciitis of the heel, lateral epicondylitis of the elbow, calcific or non-calcific tendonitis of the shoulder and patellar tendinopathy etc. The success rate ranged from 65% to 91%, and the complications were low and negligible. ESWT is also utilized in the treatment of non-union of long bone fracture, avascular necrosis of femoral head, chronic diabetic and non-diabetic ulcers and ischemic heart disease. The vast majority of the published papers showed positive and beneficial effects. FDA (USA) first approved ESWT for the treatment of proximal plantar fasciitis in 2000 and lateral epicondylitis in 2002. ESWT is a novel non-invasive therapeutic modality without surgery or surgical risks, and the clinical application of ESWT steadily increases over the years. This article reviews the current status of ESWT in musculoskeletal disorders.

  14. Dynamics and stability of an extending beam attached to an axially moving base immersed in dense fluid

    NASA Astrophysics Data System (ADS)

    Yan, H.; Ni, Q.; Dai, H. L.; Wang, L.; Li, M.; Wang, Y.; Luo, Y.

    2016-11-01

    In the present study, we construct a theoretical model for investigating the dynamics and stability of a flexible slender cantilever which is attached to an axially moving base fully immersed in an incompressible fluid. Meanwhile, the cantilevered beam is subjected to a time dependent axial extension. The coordinate transformation is utilized to derive the governing equations with consideration of an axial added mass coefficient and realistic initial conditions. Based on the Galerkin approach and Runge-Kutta technique, the numerical results for the dynamical behavior of the system under conditions of steady rate of extension and speed of the moving base are displayed. It is demonstrated that there is a critical value of extension rate at which the beam loses stability in the case when the base is fixed. As the base moves beyond a certain speed, however, the beam returns to be stable even if the extension rate is above the critical value. Furthermore, the beam system can exhibit peak response as the base moving speed is much higher than the extension rate.

  15. [Electrohydraulic shockwave lithotripsy with ventral shockwave exposure--technic, indications and initial clinical results].

    PubMed

    Miller, K; Bachor, R; Hautmann, R

    1988-05-01

    Shockwave lithotripsy of ureteral or calyceal calculi covered by the bony pelvis and of anteriorly located stones, such as calculi in horseshoe kidneys or the common bile duct, requires ventral introduction of the shockwave into the body. Eleven patients underwent ESWL in the prone position for the aforementioned indications. All treatments were performed with the Dornier HM3 lithotripter, which allows prone positioning of the patient without technical modification of the stretcher. ESWL was successful in all patients, one requiring a second session for complete stone disintegration. Thus, the possibility of shockwave lithotripsy with the patient in the prone position allows further extension of the indications for noninvasive treatment of calculi.

  16. Bacterial biofilm disruption using laser generated shockwaves.

    PubMed

    Taylor, Zachary D; Navarro, Artemio; Kealey, Colin P; Beenhouwer, David; Haake, David A; Grundfest, Warren S; Gupta, Vijay

    2010-01-01

    A system was built to test the efficacy of bacterial biofilm disruption using laser generated shockwaves. The system is based on a Q-switched, ND:YAG pulsed laser operating at a rep rate of 10 Hz with 1500 mJ pulses centered at 1064 nm. The laser pulses were used to create shockwave pulses in Al coated polycarbonate substrates and a resulting peak stress of greater than 50 MPa was measured. These stress pulses were coupled to bacteria grown to confluence on agar plates and cell death as a result of shockwave stress was assessed. The results show a 55% reduction in the number living bacteria between shocked and control samples. This type of biofilm disruption method could prove useful in the treatment of infected wounds where standard treatment methods such as debridement and topical antibiotics have proven to be ineffectual or harmful.

  17. [Shockwave cytotoxicity on neoplastic and non-neoplastic cells].

    PubMed

    Rosell, D; Robles, J E; Abad, J I; Agüera, L G; De Castro, F; Zudaire, J J; Berían, J M

    1993-07-01

    Since initial application of high-energy shockwaves to treat renal lithiasis, their usefulness has been extended within both the clinical and experimental fields. Shockwaves cytotoxic action is determined by means of cell viability methods of vital staining exclusion and nucleoside uptake. Application of shockwaves on cell cultures is carried out by means of an electromagnetic lithotripter. High-energy shockwaves have had cytotoxic action both on non-tumoral and tumoral cells, during "in vitro" experiments. The cytotoxicity produced by the shockwaves, however, is different in tumoral and non-tumoral cells, the viability inhibition being higher in tumoral cells.

  18. Biological mechanism of shockwave in bone.

    PubMed

    Cheng, Jai-Hong; Wang, Ching-Jen

    2015-12-01

    Shockwave is a rapid, short duration acoustic wave that carries energy and can propagate through tissue medium. This kind of physical force can be a mechanical stimulus that induces biological effects in living tissue. Extracorporeal shockwave therapy (ESWT) acts as a mechanical stimulus which promotes biological healing processes through a mechanotransduction. The biological effects of ESWT are reported such as tissue regeneration, wound healing, angiogenesis, bone remodeling, and anti-inflammation. Until now, however, little is known about the basic mechanism of action of this type of therapy. This article describes the molecular mechanism on the current status of ESWT with pre-clinical and clinical applications for treating disorders in bone.

  19. The effect of shockwaves on mature and healing cortical bone.

    PubMed

    Forriol, F; Solchaga, L; Moreno, J L; Canãdell, J

    1994-10-01

    It has been proposed that high energy shockwaves could be used to create microfractures in cortical bone. This quality might be exploited clinically to perform closed osteotomies and promote healing in nonunion (15). However, no study has previously documented the effect of shockwaves on cortical bone "in vivo". We report an investigation designed to demonstrate the effect of shockwaves on mature cortical and healing bone. An osteotomy was performed on the tibiae of 37 lambs; two weeks later the operation site was exposed to shockwaves. Three weeks later the lambs were killed and specimens of the bone examined histologically and radiographically. Shockwaves had no effect on the periosteal surface of mature cortical bone, but on the endosteal surface some new trabecular bone was seen. Healing of bone was delayed by the shockwave therapy. We conclude that there is currently little place for shockwave treatment in clinical orthopaedics.

  20. Use of a multichannel collimator for structural investigation of low-Z dense liquids in a diamond anvil cell: Validation on fluid H{sub 2} up to 5 GPa

    SciTech Connect

    Weck, Gunnar; Spaulding, Dylan; Loubeyre, Paul; Garbarino, Gaston; Mezouar, Mohamed; Ninet, Sandra; Datchi, Frederic

    2013-06-15

    We report the first application of a multichannel collimator (MCC) to perform quantitative structure factor measurements of dense low-Z fluids in a diamond anvil cell (DAC) using synchrotron x-ray diffraction. The MCC design, initially developed for the Paris-Edinburgh large volume press geometry, has been modified for use with diamond anvil cells. A good selectivity of the diffracted signal of the dense fluid sample is obtained due to a large rejection of the Compton diffusion from the diamond anvils. The signal to background ratio is significantly improved. We modify previously developed analytical techniques for quantitative measurement of the structure factor of fluids in DACs [J. H. Eggert, G. Weck, P. Loubeyre, and M. Mezouar, Phys. Rev. B 65, 174105 (2002)] to account for the contribution of the MCC. We present experimental results on liquids argon and hydrogen at 296 K to validate our method and test its limits, respectively.

  1. Extracorporeal shockwave therapy for peyronie disease.

    PubMed

    Groth, T; Monga, M

    2003-01-01

    While surgery is the mainstay of therapy for Peyronie disease requiring correction of angulation, interest has grown in the application of extracorporeal shockwave therapy (ESWT) as a minimally invasive approach. This article reviews the current literature reporting the use of ESWT for Peyronie disease.

  2. Extracorporeal shockwave lithotripsy of pancreatic duct stones.

    PubMed

    Rawat, B; Fache, J S; Burhenne, H J

    1992-01-01

    Encouraging results with extracorporeal shockwave lithotripsy (ESWL) for pancreatic duct stones have been reported from Europe. We present our experience with the first two North American patients, treated with excellent results in one and limited clinical improvement in the other patient at 1 year follow-up. Targeting of pancreatic duct stones was achieved with either fluoroscopy or ultrasound.

  3. Severe perinephric hemorrhage after shockwave lithotripsy.

    PubMed

    Antoniou, N K; Karanastasis, D; Stenos, J L

    1995-06-01

    We report a case of a 69-year-old man who, after a second session of shockwave lithotripsy for multiple stones in the right kidney, showed symptoms of severe hemorrhage and flank pain unresponsive to analgesics, with the gradual development of extensive and serious perinephric hematoma. The bleeding necessitated nephrectomy. Unrecognized chronic pyelonephritis may have been a predisposing factor.

  4. [Sonography and biliary extracorporeal shockwave lithotripsy (ESWL)].

    PubMed

    Jakobeit, C; Greiner, L; Rebensburg, S; Spelter, M; Schumacher, R; Frenzel, F; Pumplün, B

    1992-12-01

    Ultrasound is an indispensable tool for preliminary diagnosis ("filter function"), during treatment ("monitoring function") and in the follow-up examinations ("follow-up function") after shock-wave lithotripsy of gallstones. It permits rapid and reliable assessment of the therapeutic outcome and early identification of complications, which present-day experience has shown to be rare.

  5. Small-bowel perforation after shockwave lithotripsy.

    PubMed

    Rodrigues Netto, Nelson; Ikonomidis, Jean A; Longo, José Antonio; Rodrigues Netto, Mauricio

    2003-11-01

    A 51-year-old woman with a history of stone disease sustained two 3 x 2-mm ileal perforations during SWL (6000 shockwaves; 0.33-0.42 mJ/mm2) for a 14 x 8-mm left-sided midureteral stone. Low energy levels should be applied when ureteral stones are treated by SWL with the patient prone.

  6. [Extracorporeal shockwave lithotripsy of pancreatic calculi].

    PubMed

    Neuhaus, H; Hagenmüller, F; Classen, M

    1990-08-01

    Extracorporeal shock-wave fragmentation of pancreatic stones is a complementary non-surgical treatment in selected patients with chronic pancreatitis. The procedure has proven to be safe and technically effective. Preliminary clinical results indicate therapeutic success rates in terms of pain disappearance or reduction in more than 90% of the patients. The indication should be taken into consideration before surgical intervention.

  7. Laser-induced shockwave lithotripsy of gallstones.

    PubMed

    Ell, C; Wondrazek, F; Frank, F; Hochberger, J; Lux, G; Demling, L

    1986-05-01

    With the aid of a Q-switched Nd:YAG laser with energy transmission via a flexible glass fiber, it proves possible under laboratory conditions, to destroy gallstones reliably and reproducibly. Lithotripsy is effected mechanically via a laser-induced local shockwave.

  8. Shockwave lithotripsy of salivary duct stones.

    PubMed

    Iro, H; Schneider, H T; Födra, C; Waitz, G; Nitsche, N; Heinritz, H H; Benninger, J; Ell, C

    1992-05-30

    Surgical extirpation of the affected gland has been necessary for cases of sialolithiasis in which the stone cannot be removed by dilatation or dissection of the salivary duct. The ability of the piezoelectric lithotripter to deliver shockwaves to a small focus makes extracorporeal shockwave lithotripsy of salivary gland stones potentially safe. Its safety and efficacy have been assessed in 51 patients with symptomatic solitary salivary stones that could not be removed by conservative measures. The stones had a median diameter of 8 (range 4-18) mm and were located in the submandibular gland in 69% of patients and in the parotid gland in 31%. A total of 72 shockwave treatment sessions (maximum 3 per patient) were given under continuous sonographic monitoring. In 45 patients (88%) complete fragmentation (fragments less than or equal to 3 mm) of the concrements was achieved. No patient needed anaesthesia, sedatives, or analgesics. The only untoward effects were localised petechial haemorrhages after 10 (13%) out of 72 treatments and transient swelling of the gland immediately after delivery of shockwave in 2/72 (3%) sessions. 20 weeks after the first session 90% (46/51) of patients were free of discomfort, and 53% (27/51) were stone free. Stone-clearance rate was higher among patients with stones in the parotid gland (81%) than among those with stones of the submandibular gland (40%). Auxiliary measures such as dilatation or dissection of the salivary duct were required only in patients with stones in the submandibular gland (20%). No long-term damage to the treated salivary gland or to adjacent tissue structures was noted during the median follow-up of 9 (1-24) months. Extracorporeal piezoelectric shockwave therapy seems likely to be safe, comfortable, and effective minimally-invasive, non-surgical treatment for salivary stones.

  9. Chaotic dynamics in dense fluids

    SciTech Connect

    Posch, H.A.; Hoover, W.G.

    1987-09-01

    We present calculations of the full spectra of Lyapunov exponents for 8- and 32-particle systems with periodic boundary conditions and interacting with the repulsive part of a Lennard-Jones potential both in equilibrium and nonequilibrium steady states. Lyapunov characteristic exponents lambda/sub n/ describe the mean exponential rates of divergence and convergence of neighbouring trajectories in phase-space. They are useful in characterizing the stochastic properties of a dynamical system. A new algorithm for their calculation is presented which incorporates ideas from control theory and constraint nonequilibrium molecular dynamics. 4 refs., 1 fig.

  10. Shockwave-induced compound action potentials in the peripheral nerve.

    PubMed

    Wehner, H D; Sellier, K

    1981-01-01

    To verify a presumed interaction between shockwaves arisen by impacts of high velocity projectiles and nervous tissue an electrophysiological experiment is performed with the following results: In peripheral nerves regular compound action potentials (CAPs) are provoked by shockwaves the amplitudes of which are increased corresponding to the pressure intensity of the shockwaves. The nerve shows no electrical activity below a certain pressure threshold (0.75 bar). Saturation of the CAP amplitude occurs beyond a pressure limit of 8 bar.

  11. Ultrasonography and biliary extracorporeal shock-wave lithotripsy.

    PubMed

    Jakobeit, C; Greiner, L

    1993-05-01

    The results of shock-wave treatment of gallbladder stones depend to a very high degree on the quality and expertise of ultrasonography applied before, during, and after shock-wave disintegration of the stones. Ultrasonography is decisive in evaluating the inclusion criteria; it is the method of choice for directing the shockwave energy at the stones and monitoring the disintegration process. It is the only diagnostic modality to really demonstrate the gallbladder being free from stones.

  12. [Extracorporeal shockwave lithotripsy: experience with 1000 treatments].

    PubMed

    Zehntner, C; Ackermann, D; Zingg, E J

    1987-03-14

    6 1/2 years after the first clinical trials in Munich, extracorporeal shockwave lithotripsy is a well established method for the treatment of urinary tract calculi. The number of open surgical interventions in urolithiasis has therefore markedly diminished. In hospitals with lithotriptors open surgical procedures are less than 1% today. In the first 16 months the Department of Urology at the University of Berne performed 1000 treatments with a kidney stone lithotriptor. The treatment was successful in 93.8%, a result comparable with those of other stone centres. During the last few months the indication for the treatment has been considerably enlarged. The new lithotriptors differ in several respects from the standard model by Dornier, though basically the principle of shockwaves remains unchanged.

  13. [Extracorporeal shockwave lithotripsy of gallbladder calculi].

    PubMed

    Greiner, L; Jakobeit, C; Schumacher, R; Johanns, W

    1993-08-01

    Shockwave disintegration of gallbladder stones with lythic therapy of residual fragments is successful when all criteria of patient- and stone-selection, shockwave application and lysis are fulfilled. The "Four-S-stones" proved to be the best candidates: solitary, symptomatic, sonolucent in a sufficiently contractile gallbladder. The rate of complications is low. Stone recurrence rate (10 to 15% after three years) is much lower as in previous studies using lythic therapy only. The new therapeutic approach to gallbladder stone disease with fragmentation, spontaneous fragment-clearance and lysis of residual fragments is--as the only truly non-invasive procedure--for 10 to 20% of the patients an alternative equal to operation.

  14. International Shock-Wave Database: Current Status

    NASA Astrophysics Data System (ADS)

    Levashov, Pavel

    2013-06-01

    Shock-wave and related dynamic material response data serve for calibrating, validating, and improving material models over very broad regions of the pressure-temperature-density phase space. Since the middle of the 20th century vast amount of shock-wave experimental information has been obtained. To systemize it a number of compendiums of shock-wave data has been issued by LLNL, LANL (USA), CEA (France), IPCP and VNIIEF (Russia). In mid-90th the drawbacks of the paper handbooks became obvious, so the first version of the online shock-wave database appeared in 1997 (http://www.ficp.ac.ru/rusbank). It includes approximately 20000 experimental points on shock compression, adiabatic expansion, measurements of sound velocity behind the shock front and free-surface-velocity for more than 650 substances. This is still a useful tool for the shock-wave community, but it has a number of serious disadvantages which can't be easily eliminated: (i) very simple data format for points and references; (ii) minimalistic user interface for data addition; (iii) absence of history of changes; (iv) bad feedback from users. The new International Shock-Wave database (ISWdb) is intended to solve these and some other problems. The ISWdb project objectives are: (i) to develop a database on thermodynamic and mechanical properties of materials under conditions of shock-wave and other dynamic loadings, selected related quantities of interest, and the meta-data that describes the provenance of the measurements and material models; and (ii) to make this database available internationally through the Internet, in an interactive form. The development and operation of the ISWdb is guided by an advisory committee. The database will be installed on two mirrored web-servers, one in Russia and the other in USA (currently only one server is available). The database provides access to original experimental data on shock compression, non-shock dynamic loadings, isentropic expansion, measurements of sound

  15. [Extracorporeal shockwave lithotripsy and lymph node calcification].

    PubMed

    Higashihara, E; Fujime, M; Niijima, T

    1987-05-01

    A female patient with calculi in the left kidney and calcified lymph nodes in the vicinity of the left renal pelvis was treated successfully with extracorporeal shock wave lithotripsy. The simultaneous action of the shock waves on the calcified lymph nodes did not cause any alteration of the lymph node structure. Thus a shock-wave treatment can be carried out even in the presence of a calcified lymph node without complications.

  16. Case report: scrotal ecchymosis after shockwave lithotripsy.

    PubMed

    Aydur, Emin; Göktas, Serdar; Kibar, Yusuf; Irkilata, Hasan Cem; Ors, Fatih; Peker, A Fuat

    2006-12-01

    Shockwave lithotripsy (SWL) is the treatment of choice for most renal calculi because it is highly effective and relatively noninvasive. Although complications of SWL are relatively few, one that occurs more frequently is perirenal hematoma, usually diagnosed by radiologic procedures. We present an interesting case of scrotal ecchymosis as an unusual presentation of perirenal hematoma causing ipsilateral spermatic-vein thrombosis after SWL for a left renal stone. To our knowledge, this condition has not been reported previously.

  17. [Current status of extracorporeal shockwave lithotripsy].

    PubMed

    Wilbert, D M; Jocham, D; Eisenberger, F; Chaussy, C

    1994-11-01

    Extracorporeal shockwave lithotripsy has become an established standard procedure for the treatment of nephrolithiasis. Almost 100 lithotripters are installed in large and medium-sized urological departments in Germany. The number of treatments per year averages 660 ESWL sessions per hospital. Multifunctional use and non-urological ESWL therapy ensure maximum utilization of the lithotripter units. In additional hospitals mobile lithotripsy is provided. At present there is a trend toward ambulatory ESWL treatment.

  18. Causality violation, gravitational shockwaves and UV completion

    NASA Astrophysics Data System (ADS)

    Hollowood, Timothy J.; Shore, Graham M.

    2016-03-01

    The effective actions describing the low-energy dynamics of QFTs involving gravity generically exhibit causality violations. These may take the form of superluminal propagation or Shapiro time advances and allow the construction of "time machines", i.e. spacetimes admitting closed non-spacelike curves. Here, we discuss critically whether such causality violations may be used as a criterion to identify unphysical effective actions or whether, and how, causality problems may be resolved by embedding the action in a fundamental, UV complete QFT. We study in detail the case of photon scattering in an Aichelburg-Sexl gravitational shockwave background and calculate the phase shifts in QED for all energies, demonstrating their smooth interpolation from the causality-violating effective action values at low-energy to their manifestly causal high-energy limits. At low energies, these phase shifts may be interpreted as backwards-in-time coordinate jumps as the photon encounters the shock wavefront, and we illustrate how the resulting causality problems emerge and are resolved in a two-shockwave time machine scenario. The implications of our results for ultra-high (Planck) energy scattering, in which graviton exchange is modelled by the shockwave background, are highlighted.

  19. Simulation of shock-induced bubble collapse with application to vascular injury in shockwave lithotripsy

    NASA Astrophysics Data System (ADS)

    Coralic, Vedran

    Shockwave lithotripsy is a noninvasive medical procedure wherein shockwaves are repeatedly focused at the location of kidney stones in order to pulverize them. Stone comminution is thought to be the product of two mechanisms: the propagation of stress waves within the stone and cavitation erosion. However, the latter mechanism has also been implicated in vascular injury. In the present work, shock-induced bubble collapse is studied in order to understand the role that it might play in inducing vascular injury. A high-order accurate, shock- and interface-capturing numerical scheme is developed to simulate the three-dimensional collapse of the bubble in both the free-field and inside a vessel phantom. The primary contributions of the numerical study are the characterization of the shock-bubble and shock-bubble-vessel interactions across a large parameter space that includes clinical shockwave lithotripsy pressure amplitudes, problem geometry and tissue viscoelasticity, and the subsequent correlation of these interactions to vascular injury. Specifically, measurements of the vessel wall pressures and displacements, as well as the finite strains in the fluid surrounding the bubble, are utilized with available experiments in tissue to evaluate damage potential. Estimates are made of the smallest injurious bubbles in the microvasculature during both the collapse and jetting phases of the bubble's life cycle. The present results suggest that bubbles larger than one micrometer in diameter could rupture blood vessels under clinical SWL conditions.

  20. Current role of extracorporeal shockwave therapy in surgery.

    PubMed

    Plaisier, P W; van der Hul, R L; Terpstra, O T; Bruining, H A

    1994-02-01

    In urology the introduction of extracorporeal shockwave therapy brought a revolutionary change to the management of urinary calculi. This inspired the introduction of shockwave therapy in several fields of surgery; it has been applied as a potential alternative to several operative procedures but is still experimental. So far, the major application of shockwave therapy has been lithotripsy of stones in the gallbladder, common bile duct, pancreatic duct and salivary gland ducts. Other applications are in the non-operative management of bone healing disturbances and in the inhibition of tumour growth. Steps towards selective thrombus ablation and pretreatment of heavily calcified arteries have also been made. In this review, the applications of extracorporeal shockwave therapy in several areas of surgery are discussed. It is concluded that, for selected patients, shockwave treatment may serve as a useful addition to the surgical armamentarium.

  1. Minimizing masses in explosively driven two-shockwave physics applications

    NASA Astrophysics Data System (ADS)

    Buttler, William; Cherne, Frank; Furlanetto, Michael; Payton, Jeremy; Stone, Joseph; Tabaka, Leonard; Vincent, Samuel

    2015-06-01

    We have experimentally investigated different two-shockwave high-explosives (HE) physics package designs to maximize the variability of the second shockwave peak stress, while minimizing the total HE load of the physics tool. A critical requirement is to also have a large radial diameter of the second shockwave to maintain its value as an HE driven two-shockwave drive. We have previously shown that we could vary the peak-stress of the second-shockwave with a 76 mm diameter HE lens driving different composite boosters of PBX 9501 and TNT. Here we report on our results with a 56- and 50-mm diameter HE lens driving Baritol. The results indicate that the 56-mm diameter HE lens works well, as does the Baritol, giving total HE loads of about 250 mg TNT equivalent explosives.

  2. Extracorporeal shockwave lithotripsy: role of the radiologist.

    PubMed

    Barth, K H; Pahira, J J; Elliott, L P

    1985-06-01

    Extracorporeal shockwave lithotripsy (ESWL) is a new noninvasive treatment modality for urinary calculi. ESWL may be applied to the majority of patients requiring stone removal and is expected to replace, to a large degree, percutaneous stone removal (PSR), now practiced jointly by interventional radiologists and endourologists in most institutions. In a number of cases, ESWL and PSR will be complementary procedures. Technically, ESWL can be considered a radiologic procedure; thus far, radiologists are not participating in its use. In the authors' opinion, ESWL should be a combined urologic radiologic procedure analogous to PSR; this will allow the most rational and effective treatment.

  3. Perinephric abscess following extracorporeal shockwave lithotripsy.

    PubMed

    Pautler, Stephen E.; Vallely, John F.; Denstedt, John D.

    1998-10-01

    Since the introduction and widespread use of extracorporeal shockwave lithotripsy (SWL), various complications have been noted. Perinephric hematoma and ureteral obstruction may be anticipated by urologists as potential problems. We report the first case of perinephric abscess encountered after 17 895 SWL treatments at our institution. A 65 year old woman presented 4 months following a second SWL procedure with a perinephric abscess and was successfully treated with percutaneous drainage. A review of the English literature revealed only 3 other cases of perinephric abscess following SWL. This diagnosis should be considered in early and late presentations of flank pain following SWL.

  4. [Extracorporeal shockwave lithotripsy in sedation-analgesia].

    PubMed

    Berger, M; Brandstetter, A; Chowanetz, E; Gasser, G; Mossig, H; Schmidt, P

    1988-03-01

    The aim of the present study was to examine the effects of combined sedation and analgesia during extracorporeal shockwave lithotripsy using the Dornier lithotriptor HM III. We used a combination of a benzodiazepin derivatives with an opioid. We tested the dosage of drugs needed in relation to the length of treatment, the size of the stone and the overall energy output of the lithotriptor. In addition, continuous records were made of the patient's blood pressure and the oxygen saturation in the blood, with and without oxygen insufflation. Our results show that sedation combined with analgesia is a reasonable and useable alternative to general or regional anaesthesia for extracorporeal lithotripsy.

  5. Extracorporeal shockwave therapy in diabetic foot ulcers.

    PubMed

    Wang, Ching-Jen; Cheng, Jai-Hong; Kuo, Yur-Ren; Schaden, Wolfgang; Mittermayr, Rainer

    2015-12-01

    Diabetic foot ulcers (DFUs) are among the most common foot disorders with ulceration, infection, and gangrene that may ultimately lead to lower extremity amputation. The goals of treatment include the control of diabetes and proper shoe wear. An effective therapy and appropriate foot care are important in wound healing in DFUs. Recently, extracorporeal shockwave therapy (ESWT) was reported to significantly promote and accelerate the healing of complex soft tissue wounds as compared to the standard methods of treatment in DFUs. ESWT showed positive results in short-term and long-term outcomes in diabetic patients suffering from foot ulcers. In this article, we review the clinical results of ESWT in DFUs.

  6. [Extracorporeal shockwave nephro-uretero-lithotripsy].

    PubMed

    Lopatkin, N A; Martov, A G; Beshliev, L A

    1992-01-01

    Extracorporeal shock-wave lithotripsy (ESWL) has been widely introduced in the treatment of nephro-uretero-lithiasis during the last decade as it provides a noninvasive removal of the stones from the upper urinary tracts. The paper covers the history, techniques, indications, contraindications, anesthesia, complications and results of the method. Positive and negative characteristics of ESWL equipment (lithotriptors) are considered. The experience with 5000 lithotripsies led the authors to the conclusion that ESWL does not solve all the problems in the treatment of nephro-uretero-lithiasis and should be introduced only in large clinics practicing actively x-ray endoscopy and equipped with modern endoscopic and ultrasonic urologic units.

  7. [Gallstone treatment by electrohydraulic extracorporeal shockwave lithotripsy].

    PubMed

    Janowitz, P; Kratzer, W; Wechsler, J G; Kuhn, K; Janowitz, A; Swobodnik, W; Ditschuneit, H

    1991-08-30

    Extracorporeal shockwave lithotripsy (ESWL) with an electrohydraulic system was performed in 124 patients (33 men, 91 women; mean age 50.1 +/- 12.7 years). Sufficient stone fragmentation was achieved in 122 patients (98.3%). ESWL was repeated in 29 patients (23.3%), twice in 7 patients (5.6%). Average shockwave application per patient was 1,441 +/- 414 impulses, at a mean energy of 20.0 +/- 1.6 kV. Mean stone diameter before ESWL was 16.2 +/- 4.2 (7-30) mm, 7.1 +/- 4.1 (0-19) mm after ESWL. Computed tomography, performed immediately after ESWL in 88 patients demonstrated hypodense thickening (3-10 mm) of the gallbladder wall in 28.4% of patients. This was interpreted as wall oedema, reversible in all. One patient had a covered gallbladder rupture and two had biliary pancreatitis. None of the patients required emergency surgery. 93 patients (74.9%) had no stones 12 months later. A high success rate can be achieved if certain criteria are adhered to and suitable patients are selected.

  8. Short-term bioeffects of extracorporeal shockwave lithotripsy.

    PubMed

    Akdaş, A; Türkeri, L N; Ilker, Y; Simşek, F; Emerk, K

    1994-06-01

    Safety guidelines for shockwave delivery during extracorporeal shockwave lithotripsy (SWL) are not yet clear. Renal functions were assessed by using urinary N-acetyl-beta-D-glucosaminidase (NAG), lactate dehydrogenase (LDH), alanine aminotransferase (ALT; EC.2.6.1.2), aspartate aminotransferase (AST; EC. 2.6.1.1), and gamma-glutamyltransferase (GGT) as well as sodium, potassium, and calcium concentrations in respect to tubular functions after SWL with the Dornier MFL 5000 unit in 32 patients. In order to monitor glomerular function, we determined microalbuminuria. Transient glomerular and tubular damage occurs in SWL-treated kidneys. The minimum interval between two shockwave treatments should be at least 7 days.

  9. Superior mesenteric artery dissection after extracorporeal shockwave lithotripsy.

    PubMed

    Bakoyiannis, Christos; Anastasiou, Ioannis; Koutsoumpelis, Andreas; Fragiadis, Evangelos; Felesaki, Eleni; Kafeza, Marina; Georgopoulos, Sotirios; Tsigris, Christos

    2012-01-01

    The use of shockwave lithotripsy is currently the mainstay of treatment in renal calculosis. Several complications including vessel injuries have been implied to extracorporeal shockwave lithotripsy. We report an isolated dissection of the superior mesenteric artery in a 60-year-old male presenting with abdominal pain which occurred three days after extracorporeal shockwave lithotripsy. The patient was treated conservatively and the abdominal pain subsided 24 hours later. The patient's history, the course of his disease, and the timing may suggest a correlation between the dissection and the ESWL.

  10. Extracorporeal shockwave therapy in a dog with chronic bicipital tenosynovitis.

    PubMed

    Venzin, C; Ohlerth, S; Koch, D; Spreng, D

    2004-03-01

    A 15-month-old, spayed female, Bernese mountain dog was presented to the Institute of Small Animal Surgery at the University of Zurich because of chronic left forelimb lameness. The referring veterinarian diagnosed pain in the left shoulder region and had treated the dog with systemic non-steroidal anti-inflammatory drugs and restricted exercise for a two-week period. The follow-up examination revealed only minimal improvement and therefore, the dog was referred for further diagnostic evaluation. Chronic bicipital tenosynovitis and tendinitis of the infraspinatus muscle was diagnosed based on survey radiographs, arthrography, ultrasound, computed tomography (CT), and synovial fluid cytology. The dog underwent three sessions of extracorporeal shockwave therapy and substantial clinical improvement was observed. On follow-up examinations, only mild left forelimb lameness was evident following exercise, and changes in the intertubercular groove and at the supraglenoid tuberosity appeared less active on radiographs and CT. However, six months following treatment, mild degenerative joint disease was apparent.

  11. Shock-Wave Compression and Joule-Thomson Expansion

    NASA Astrophysics Data System (ADS)

    Hoover, Wm. G.; Hoover, Carol G.; Travis, Karl P.

    2014-04-01

    Structurally stable atomistic one-dimensional shock waves have long been simulated by injecting fresh cool particles and extracting old hot particles at opposite ends of a simulation box. The resulting shock profiles demonstrate tensor temperature, Txx≠Tyy and Maxwell's delayed response, with stress lagging strain rate and heat flux lagging temperature gradient. Here this same geometry, supplemented by a short-ranged external "plug" field, is used to simulate steady Joule-Kelvin throttling flow of hot dense fluid through a porous plug, producing a dilute and cooler product fluid.

  12. Extracorporeal shockwave lithotripsy for kidney stone on surgical clip.

    PubMed

    Clark, J Y; Kearse, W S

    1997-04-01

    We report the successful use of extracorporeal shockwave lithotripsy for the destruction of a renal stone that had formed around a surgical clip. The SWL led to passage of both the stone and the clip.

  13. [The history of extracorporeal shockwave lithotripsy in Spain].

    PubMed

    Ruíz Marcellán, Francisco Javier; Ibarz Servio, Luis

    2007-10-01

    We give a historical outline of urinary lithiasis with emphasis in the alternative therapeutic options to surgery. We expose the previous steps that led to the birth of extracorporeal shockwave lithotripsy and its implementation in our country.

  14. SHOCK-WAVE THERAPY APPLICATION IN CLINICAL PRACTICE (REVIEW).

    PubMed

    Sheveleva, N; Minbayeva, L; Belyayeva, Y

    2016-03-01

    The article presents literature review on the use of extracorporeal shock-wave therapy in physiotherapeutic practice. The basic mechanisms of shock waves influence on the organism are spotlighted. Studies proving high efficacy of the method in treatment of wide variety of inflammatory diseases and traumatic genesis are presented. The data on comparative assessment of shock-wave therapy efficacy, and results of researches on possibility of extracorporeal shock-wave therapy effect potentiating in combination with other therapeutic methods are reflected. Recent years, the range of indications for shock-wave therapy application had been significantly widened. However, further study of the method is still relevant because mechanisms of action of the factor are studied insufficiently; methods of therapy parameters selection (energy flux density, number of pulses per treatment, duration of a course) are either advisory or empirical.

  15. Shockwave determination of the shear velocity at very high pressures.

    NASA Technical Reports Server (NTRS)

    Anderson, O. L.

    1972-01-01

    Description of a proposed shockwave experiment that may provide some understanding on the behavior of planet core materials in the presence of high temperatures and pressures. Shockwave experimentation is shown to offer promise of revealing some information on shear velocity behavior at high pressures, and its relevance to properties of planet interiors consists in that abrupt changes in shear velocities at boundary layers could be experimentally confirmed where abrupt changes in density are suspected from seismic interpretation.

  16. [New trends in extracorporeal shockwave lithotripsy].

    PubMed

    Folberth, W

    1992-03-01

    Extracorporeal shock wave lithotripsy has become an established and successful treatment modality for urinary and biliary calculi. However, shock wave technology and corresponding device designs are still at an innovative stage. Three trends are discussed in this paper. In shock wave technology the electromagnetic principle seems to win the race. The demands for successful and tissue-protective stone disintegration require shockwave sources with high dynamic range and optimised focal geometry. Electromagnetic shock wave generators meet all these requirements. For stone localisation an isocentric X-ray targeting system combined with integrated shock wave application is accepted as the "gold standard". In ultrasound localisation in-line targeting is superior to out-of-line targeting.

  17. [Application of extracorporeal shockwave therapy in andrology].

    PubMed

    Qin, Xin; Lu, Yi-Ping

    2012-12-01

    Extracorporeal shockwave therapy (ESWT) has been widely used in various fields ever since it was first introduced for the treatment of urinary stones in 1983. Recent years see a growing application of ESWT to andrology. Studies show that ESWT can relieve pain in 83% of the patients with Peyronie's disease, and has won favorable comments from 66% of the patients. ESWT can significantly improve the sexual life quality of the patients with organic erectile dysfunction, yields good effect in the treatment of chronic nonbacterial prostatitis, especially in pain relief. ESWT has offered new ideas and options for the treatment of andrological diseases. However, its mechanisms have yet to be clarified by more in-depth basic studies and multi-centered, large-sample randomized controlled trials.

  18. Extracorporeal shockwave lithotripsy of distal ureteral calculi.

    PubMed

    Miller, K; Bubeck, J R; Hautmann, R

    1986-01-01

    To date, the use of extracorporeal shockwave lithotripsy (ESWL) has been limited to renal calculi and ureteral calculi above the pelvic brim. Modifying the position of the patient on the support of the Dornier lithotripter HM3, we were able to localize and treat distal ureteral calculi. Until April 1986, 43 patients with stones in the lower ureter underwent contact-free lithotripsy. Treatment was successful in 39 patients (90%), 2 of these requiring 2 sessions. In 4 patients treatment failed and stone removal was accomplished using ureteroscopy or open surgery. No complications or adverse side effects were encountered in the whole series. ESWL is now the method of choice for the treatment of distal ureteral calculi in our department.

  19. Shockwave-boundary layer interference heating analysis.

    NASA Technical Reports Server (NTRS)

    Hung, F. T.; Barnett, D. O.

    1973-01-01

    Interference heating correlations have been developed based on existing wind tunnel test data taken with simple configurations such as wedge/flat plate and compression corner models. For turbulent flow, peak interference heating was first correlated with shock strength (pressure ratio across shock wave) and then as a function of Reynolds number. The peak interference Stanton number was found to exhibit the same Reynolds number and Prandtl number characteristics as the Stanton number variation for undisturbed flow over a flat plate. Similar correlations were developed for laminar flow. Results indicated that for laminar flow at higher Reynolds number, the impinging shockwave may act as a boundary layer trip and cause boundary layer transition resulting in high interference heating. The correlations derived in this study can be used to scale wind tunnel model test data to a full-scale space vehicle at supersonic or hypersonic flight conditions.

  20. Shockwave loading of mechanochemically active polymer coatings.

    PubMed

    Grady, Martha E; Beiermann, Brett A; Moore, Jeffrey S; Sottos, Nancy R

    2014-04-23

    Thin films of mechanochemically active polymer were subjected to laser-generated, high amplitude acoustic pulses. Stress wave propagation through the film produced large amplitude stresses (>100 MPa) in short time frames (10-20 ns), leading to very high strain rates (ca. 1 × 10(7) to 1 × 10(8) s(-1)). The polymer system, spiropyran (SP)-linked polystyrene (PS), undergoes a force-induced chemical reaction causing fluorescence and color change. Activation of SP was evident via a fluorescence signal in thin films subject to high strain-rates. In contrast, quasi-static loading of bulk SP-linked PS samples failed to result in SP activation. Mechanoresponsive coatings have potential to indicate deformation under shockwave loading conditions.

  1. Does extracorporeal shockwave lithotripsy cause hypertension?

    PubMed

    Montgomery, B S; Cole, R S; Palfrey, E L; Shuttleworth, K E

    1989-12-01

    Several series have suggested that the incidence of hypertension following extracorporeal shockwave lithotripsy (ESWL) may be as high as 8%. In this study, changes in blood pressure and the incidence of hypertension have been observed in 733 patients 12 to 44 months after renal ESWL on the Dornier HM3. The incidence of hypertension following ESWL was 8.1%. In patients with a pre-ESWL diastolic pressure less than 90 mmHg, the incidence of those with a diastolic greater than or equal to 100 mm Hg post-operatively was significantly greater than that predicted by historical data. There was no overall change in the mean blood pressure of the group. The hypertensive risk of ESWL remains unclear. However, blood pressure surveillance should be performed following ESWL and a prospective study is required.

  2. Extracorporeal shockwave lithotripsy in anomalous kidneys.

    PubMed

    Baltaci, S; Sarica, K; Ozdiler, E; Dinçel, C; Küpeli, S; Gögüş, O

    1994-06-01

    Traditionally, stones in anomalous kidneys have been removed by open or percutaneous surgery. Extracorporeal shockwave lithotripsy (SWL) with the Dornier MPL 9000 lithotripter was performed in seven patients with horseshoe kidneys, four with pelvic ectopic kidneys, and six with malrotated kidneys. Twelve patients (71%) needed repeated treatments. A total of 11 patients (65%) in all the groups were stone free, and four patients had asymptomatic residual fragments no more than 5 mm in diameter. In the remaining two patients, no sign of stone disintegration was observed, and they underwent open surgery. Extracorporeal lithotripsy is the treatment of choice for stones in horseshoe or malrotated kidneys but is not useful for stones in most pelvic kidneys.

  3. Influence of shockwave profile on ejecta

    SciTech Connect

    Zellner, Michael B; Dimonte, Guy; Germann, Tim C; Hammerberg, James E; Rigg, Paulo A; Buttler, William T; Stevens, Gerald D; Turley, William D

    2009-01-01

    This effort investigates the relation between shock-pulse shape and the amount of micron-scale fragments ejected (ejecta) upon shock release at the metal/vacuum interface of shocked Sn targets. Two shock-pulse shapes are considered: a supported shock created by impacting a Sn target with a sabot that was accelerated using a powder gun; and an unsupported or Taylor shockwave, created by detonation of high explosive that was press-fit to the front-side of the Sn target. Ejecta production at the back-side or free-side of the Sn coupons were characterized through use of piezoelectric pins. Assay foils, optical shadowgraphy, and x-ray attenuation.

  4. Lipid peroxidation induced by shockwave lithotripsy.

    PubMed

    Cohen, T D; Durrani, A F; Brown, S A; Ferraro, R; Preminger, G M

    1998-06-01

    To determine the relation between high-energy shockwaves (HESW) and the presence of lipid peroxidation produces, juvenile pigs were subjected to shockwave lithotripsy (SWL). After lithotripsy, both treated and control kidneys were analyzed, along with urine samples collected before, during, and after SWL. Thiobarbituric acid-reactive substance (TBARS) and lipid-conjugated diene (CD) concentrations, used as markers for membrane lipid peroxidation, were determined in the kidney and urine samples. Significantly increased mean TBARS concentrations (146%) were associated with homogenates of lithotripsy-treated kidneys, 77.8 +/- 14.4 (SD) mmol/g v the controls, 31.4 +/- 14.9 mmol/g. Lithotripsy induction of lipid peroxidation products in the cortex, the gross damage site, and the respective medulla were also examined. In HESW-treated cortex samples, increased TBARS concentrations were seen--75.0 +/- 21.3 mmol/g--compared with untreated controls-- 45.2+/- 5.6 mmol/g--while increased CD concentrations (168%) were observed in the medulla of HESW-treated samples. No significant differences were observed in TBARS or CD concentrations in urine samples from control or treated kidneys, yet specific lipid hydroperperoxides were detected in the urine of HESW-treated kidneys. We conclude that HESW lithotripsy of swine kidneys is associated with increased lipid peroxidation products that may cause further cellular damage. Lipid peroxidation induced by SWL may be one of several mechanisms that lead to other potential bioeffects. Finally, analysis of specific lipid hydroperoxides in the urine of HESW-treated kidneys may serve as a noninvasive marker of renal injury after clinical SWL.

  5. Time Resolved Shadowgraph Images of Silicon during Laser Ablation:Shockwaves and Particle Generation

    SciTech Connect

    Liu, C.Y.; Mao, X.L.; Greif, R.; Russo, R.E.

    2006-05-06

    Time resolved shadowgraph images were recorded of shockwaves and particle ejection from silicon during laser ablation. Particle ejection and expansion were correlated to an internal shockwave resonating between the shockwave front and the target surface. The number of particles ablated increased with laser energy and was related to the crater volume.

  6. Pathophysiologic effects of biliary shockwave lithotripsy in a canine model.

    PubMed

    Chapman, W C; Parish, K L; Kaufman, A J; Stephens, W H; Anderson, S; Woodward, S; Williams, L F

    1991-01-01

    At least 10 extracorporeal shockwave lithotripters are under investigation in the United States for treatment of biliary stone disease. Few reports, however, have documented the potential side effects of this new treatment method. In this study, we performed a series of acute and chronic studies in dogs exposed to varying numbers of shockwaves directed at the gallbladder wall via a transthoracic or transabdominal targeting approach. When shockwaves were directed transthoracically, pulmonary hemorrhagic contusions were found which were sometimes large in size. When a transabdominal approach was used, however, only focal areas of hemorrhage were found in the gallbladder wall and adjacent liver with no alterations in postlithotripsy pancreatic or liver enzymes, and normal cholecystokinin-octapeptide stimulated oral cholecystograms were obtained 6 days after treatment. Biliary shockwaves appear to cause few side effects under normal conditions but should be used with caution in patients with potential bleeding disorders. Until further studies are performed, lung tissue should be avoided in the shockwave beam path during treatment. PMID:1796795

  7. Mechanisms of differing stone fragility in extracorporeal shockwave lithotripsy.

    PubMed

    Zhong, P; Preminger, G M

    1994-08-01

    Clinical experience with extracorporeal shockwave lithotripsy (SWL) has demonstrated significant variations in stone fragility. To understand the physical mechanisms of the differences, we quantitatively determined shockwave-stone interaction under clinically relevant SWL conditions for six stone compositions: calcium oxalate monohydrate (COM), struvite (MAPH), calcium apatite (CA), uric acid (UA), brushite, and cystine. We also characterized the acoustic and mechanical properties of the stones using ultrasound and microindentation techniques. Our results show that renal calculi have distinctly different acoustic and mechanical properties. Higher wave speed, Young's modulus, and fracture toughness were measured from COM and cystine stones, whereas lower values of the corresponding properties were found in CA and MAPH, and the values for brushite and UA stones were in between. Computer modeling of shockwave propagation revealed that under the same shockwave intensity, larger deformation was induced in CA and MAPH stones than in COM and cystine stones. In addition, multiple reflected tensile waves were predicted for stones with concentric layer structure, indicating their susceptibility to shockwave fragmentation. These findings elucidate the mechanisms of the differences in stone fragility observed clinically. Their implications to SWL are discussed.

  8. Pathophysiologic effects of biliary shockwave lithotripsy in a canine model.

    PubMed

    Chapman, W C; Parish, K L; Kaufman, A J; Stephens, W H; Anderson, S; Woodward, S; Williams, L F

    1991-01-01

    At least 10 extracorporeal shockwave lithotripters are under investigation in the United States for treatment of biliary stone disease. Few reports, however, have documented the potential side effects of this new treatment method. In this study, we performed a series of acute and chronic studies in dogs exposed to varying numbers of shockwaves directed at the gallbladder wall via a transthoracic or transabdominal targeting approach. When shockwaves were directed transthoracically, pulmonary hemorrhagic contusions were found which were sometimes large in size. When a transabdominal approach was used, however, only focal areas of hemorrhage were found in the gallbladder wall and adjacent liver with no alterations in postlithotripsy pancreatic or liver enzymes, and normal cholecystokinin-octapeptide stimulated oral cholecystograms were obtained 6 days after treatment. Biliary shockwaves appear to cause few side effects under normal conditions but should be used with caution in patients with potential bleeding disorders. Until further studies are performed, lung tissue should be avoided in the shockwave beam path during treatment.

  9. Effect of shockwave therapy on plantar fasciopathy. A biomechanical prospective.

    PubMed

    Hsu, W-H; Lai, L-J; Chang, H-Y; Hsu, R W-W

    2013-08-01

    It has been suggested that extracorporeal shockwave therapy is a safe and effective treatment for pain relief from recalcitrant plantar fasciopathy (PF). However, the changes in gait and associated biomechanical parameters have not been well characterised. We recruited 12 female patients with recalcitrant PF who had a mean age of 59 years (50 to 70) and mean body mass index of 25 kg/m(2) (22 to 30). The patients reported a mean duration of symptoms of 9.3 months (6 to 15). Shockwave therapy consisting of 1500 impulses (energy flux density 0.26 mJ/mm(2)) was applied for three sessions, each three weeks apart. A pain visual analogue scale (VAS) rating, plantar pressure assessment and motion analysis were carried out before and nine weeks after first shock wave therapy. It was demonstrated that patients increased their walking velocity and cadence as well indicating a decrease in pain after shockwave therapy. In the symptomatic foot, the peak contact pressure over the forefoot increased and the contact area over the digits decreased. The total foot impulse also decreased as did stance duration. The duration the centre of pressure remained in the hindfoot increased in the symptomatic foot after shockwave therapy. The differences in centre of pressure trajectory at baseline decreased at final follow-up. In conclusion, shockwave therapy not only decreased the pain VAS rating but also improved the gait parameters of the symptomatic foot in PF patients.

  10. [Extracorporeal shockwave lithotripsy in gallstone perforation].

    PubMed

    Jakobeit, C

    1992-04-01

    A 78-year-old man with rheumatoid arthritis, arteriosclerosis and cardiac arrhythmias (Lown grade IVb) was admitted to hospital because of haematemesis. Gastroscopy revealed a narrow, deformed duodenal bulb with a bleeding ulcer crater on the posterior wall and a mucosal protrusion 1 cm in diameter. In the course of the illness the duodenal bulb obstruction increased further and there was recurrent vomiting. Repeat gastroscopy 7 days later showed a gallstone, about 4 cm in diameter, which had perforated into the duodenal bulb and could not be removed endoscopically. Because of the serious nature of the other diseases an operation was not undertaken, but an ultrasound-guided extracorporeal shockwave lithotripsy was performed. In three sessions this succeeded without complication to break up the stone, the larger fragments of which were then removed endoscopically while the small ones passed through the gut spontaneously. Subsequent ultrasonography demonstrated a shrunk, stone-free gallbladder with a cholecystoduodenal fistula. Afterwards the patient was again able to take food by mouth without any problems.

  11. Renal rupture following extracorporeal shockwave lithotripsy.

    PubMed

    Torbati, Sam S; Niku, Michelle; Vos, Elaine; Hogan, Shomari

    2014-09-01

    A 41-year-old woman presented to the emergency department with a chief complaint of hematuria three days status post extracorporeal shockwave lithotripsy. The patient described a three-day history of worsening left-sided abdominal pain immediately following the procedure. She denied any fever, chills, changes in bowel habits, hematochezia, increased urinary frequency, urinary urgency, or dysuria. Physical exam revealed tenderness to palpation in the left upper quadrant, left flank and periumbilical region with mild guarding. Laboratory studies revealed an anemic patient with downward trending hematocrit (red blood cell count of 3.41 10(6)/μL, hemoglobin of 10.6 g/dL, and a hematocrit of 31.3% down from 43% a week and a half prior). Urinalysis revealed red and cloudy urine with 3+ leukocytes. A chest radiograph was unremarkable. A computed tomography of the chest, abdomen, and pelvis showed a laceration to the lateral aspect of the mid left kidney with a hematoma measuring 3.2 cm in thickness (Figure). The patient was subsequently admitted to the hospital for monitoring and discharged on day nine.

  12. [Biliary extracorporeal shockwave lithotripsy. Preliminary communication].

    PubMed

    Garnica, E

    1989-01-01

    Shock wave lithotripsy has been successfully used in the treatment of urinary stones. Since 1985, it has also been applied in the management of gallbladder and biliary duct stones. The preliminary experience in Venezuela with the shock wave technology for the treatment of biliary stone disease is presented. The facilities of the Unit for the Treatment of Lithiasis. UNILIT of Venezuela, in Caracas were used. This unit is equipped with a Siemens Lithostar, that operates with an electromagnetic shock wave generator guided by a very accurate computerized biplane fluoroscopic system. Symptomatic gallstones with functioning gallbladder and radiolucid stones smaller than 3 cm, were the most important inclusion criteria. For duct stones, all cases that could not be managed by endoscopy were included. Fifteen cases have been treated from April 1988. Ten with gallstones and 5 with biliary duct stones. Success rate for gallstones, clarifications of gallbladder within a 12 month follow-up, was achieved in 40%. In the cases of biliary duct lithiasis, the aim was to reduce the stone to smaller fragments that could pass spontaneously or be retrieved by endoscopic maneuvers. In all the five cases treated, the stones could be crushed into small fragments and in four, they were easily withdrawn by endoscopic ballooning. Preliminary results and published data suggest that shockwave lithotripsy is a valuable method of treatment for selected cases of gallbladder stones and it is specially useful in the management of biliary duct stones where the endoscopic maneuvers have failed.

  13. Process for combining the regeneratorless operation of tandem super-dense riser and fluid-bed oligomerization reactors containing a zeolite oligomerization catalyst

    SciTech Connect

    Harandi, M.N.; Owen, H.

    1990-05-15

    This patent describes a catalytic process for upgrading a C{sub 2}{sup +} olefin feedstream to a heavier product stream rich in C{sub 10}{sup +} aliphatic hydrocarbons in first and second oligomerization zones. It comprises: contacting the olefin feedstream in the first zone with a finely divided medium pore size zeolite metallosilicate catalyst having a silica:alumina ratio grater than 12, and a constraint index in the range from about 1 to about 12, at a weight hourly space velocity (WHSV) sufficient to maintain a transport zone, and, then with essentially the same catalyst maintained as a fluid bed, the first zone containing riser catalyst having a higher coke content than that of catalyst in the second zone maintained in a turbulent regime.

  14. Current concepts of shockwave therapy in stress fractures.

    PubMed

    Leal, Carlos; D'Agostino, Cristina; Gomez Garcia, Santiago; Fernandez, Arnold

    2015-12-01

    Stress fractures are common painful conditions in athletes, usually associated to biomechanical overloads. Low risk stress fractures usually respond well to conservative treatments, but up to one third of the athletes may not respond, and evolve into high-risk stress fractures. Surgical stabilization may be the final treatment, but it is a highly invasive procedure with known complications. Shockwave treatments (ESWT), based upon the stimulation of bone turnover, osteoblast stimulation and neovascularization by mechanotransduction, have been successfully used to treat delayed unions and avascular necrosis. Since 1999 it has also been proposed in the treatment of stress fractures with excellent results and no complications. We have used focused shockwave treatments in professional athletes and military personnel with a high rate of recovery, return to competition and pain control. We present the current concepts of shockwave treatments for stress fractures, and recommend it as the primary standard of care in low risk patients with poor response to conventional treatments.

  15. Interaction of lithotripter shockwaves with single inertial cavitation bubbles.

    PubMed

    Klaseboer, Evert; Fong, Siew Wan; Turangan, Cary K; Khoo, Boo Cheong; Szeri, Andrew J; Calvisi, Michael L; Sankin, Georgy N; Zhong, Pei

    2007-01-01

    The dynamic interaction of a shockwave (modelled as a pressure pulse) with an initially spherically oscillating bubble is investigated. Upon the shockwave impact, the bubble deforms non-spherically and the flow field surrounding the bubble is determined with potential flow theory using the boundary-element method (BEM). The primary advantage of this method is its computational efficiency. The simulation process is repeated until the two opposite sides of the bubble surface collide with each other (i.e. the formation of a jet along the shockwave propagation direction). The collapse time of the bubble, its shape and the velocity of the jet are calculated. Moreover, the impact pressure is estimated based on water-hammer pressure theory. The Kelvin impulse, kinetic energy and bubble displacement (all at the moment of jet impact) are also determined. Overall, the simulated results compare favourably with experimental observations of lithotripter shockwave interaction with single bubbles (using laser-induced bubbles at various oscillation stages). The simulations confirm the experimental observation that the most intense collapse, with the highest jet velocity and impact pressure, occurs for bubbles with intermediate size during the contraction phase when the collapse time of the bubble is approximately equal to the compressive pulse duration of the shock wave. Under this condition, the maximum amount of energy of the incident shockwave is transferred to the collapsing bubble. Further, the effect of the bubble contents (ideal gas with different initial pressures) and the initial conditions of the bubble (initially oscillating vs. non-oscillating) on the dynamics of the shockwave-bubble interaction are discussed.

  16. [Extracorporeal shock-wave lithotripsy of a salivary stone].

    PubMed

    Iro, H; Schneider, T; Nitsche, N; Waitz, G; Marienhagen, J; Ell, C

    1990-01-01

    Ultrasonography revealed a 12 mm concrement in the left parotid duct of a 67-year-old man with an acute exacerbation of a left-sided purulent parotitis. After the acute phase had subsided under antibiotic therapy it was not possible to remove the stone either by bougie or cutting into the duct close to the papilla. Piezoelectric shockwave lithotripsy with a total of 1000 shock-waves fragmented the stone, and sonography 48 hours and four weeks later demonstrated that the parotid gland was free of stone.

  17. Does respiratory gating improve extracorporeal shockwave lithotripsy results?

    PubMed

    Sade, M; Guler, C; Esen, A A; Kirkali, Z

    1994-10-01

    The reliability and efficacy of extracorporeal shockwave lithotripsy (SWL) has been established in urinary stone disease. Its combination with respiratory gating might be a useful method to increase the effectiveness of treatment and reduce the number of shocks required. For this purpose, the results of SWL combined with respiratory gating were compared with those of SWL without gating. There was no difference in the stone-free rates of the two groups or in the complication rate. It is concluded that this method neither decreases the number of shockwaves needed nor increases the effectiveness of SWL.

  18. Quantitative Assessment of Shockwave Lithotripsy Accuracy and the Effect of Respiratory Motion*

    PubMed Central

    Bailey, Michael R.; Shah, Anup R.; Hsi, Ryan S.; Paun, Marla; Harper, Jonathan D.

    2012-01-01

    Abstract Background and Purpose Effective stone comminution during shockwave lithotripsy (SWL) is dependent on precise three-dimensional targeting of the shockwave. Respiratory motion, imprecise targeting or shockwave alignment, and stone movement may compromise treatment efficacy. The purpose of this study was to evaluate the accuracy of shockwave targeting during SWL treatment and the effect of motion from respiration. Patients and Methods Ten patients underwent SWL for the treatment of 13 renal stones. Stones were targeted fluoroscopically using a Healthtronics Lithotron (five cases) or Dornier Compact Delta II (five cases) shockwave lithotripter. Shocks were delivered at a rate of 1 to 2 Hz with ramping shockwave energy settings of 14 to 26 kV or level 1 to 5. After the low energy pretreatment and protective pause, a commercial diagnostic ultrasound (US) imaging system was used to record images of the stone during active SWL treatment. Shockwave accuracy, defined as the proportion of shockwaves that resulted in stone motion with shockwave delivery, and respiratory stone motion were determined by two independent observers who reviewed the ultrasonographic videos. Results Mean age was 51±15 years with 60% men, and mean stone size was 10.5±3.7 mm (range 5–18 mm). A mean of 2675±303 shocks was delivered. Shockwave-induced stone motion was observed with every stone. Accurate targeting of the stone occurred in 60%±15% of shockwaves. Conclusions US imaging during SWL revealed that 40% of shockwaves miss the stone and contribute solely to tissue injury, primarily from movement with respiration. These data support the need for a device to deliver shockwaves only when the stone is in target. US imaging provides real-time assessment of stone targeting and accuracy of shockwave delivery. PMID:22471349

  19. [Extracorporeal shockwave lithotripsy of the ureteral calculus--clinical results with local shockwave lithotripsy].

    PubMed

    Wilbert, D M; Voges, G E; Müller, S C; Alken, P

    1987-11-01

    Second generation local shockwave lithotripsy appliances (Lithostar) were used for the treatment of upper and lower ureteral stones in 199 patients, 145 of whom had upper ureteral stones. In 78 patients the calculi were pushed back and all but one disintegrated. In 33 patients a catheter was inserted past the stone, which resulted of primary disintegration in 66%. In 19 of 34 patients (56%) in whom the stones could not be moved, primary disintegration was achieved. Distal ureteral stones were present in 54 patients and these were treated successfully by ESWL alone in 83.3%. Auxiliary measures (total 10%) included ureteroscopy, percutaneous extraction and ureterolithotomy. The results are discussed under the aspects of 'in situ' versus 'push-and-smash' procedures.

  20. Developing Multimedia Courseware for the Internet's Java versus Shockwave.

    ERIC Educational Resources Information Center

    Majchrzak, Tina L.

    1996-01-01

    Describes and compares two methods for developing multimedia courseware for use on the Internet: an authoring tool called Shockwave, and an object-oriented language called Java. Topics include vector graphics, browsers, interaction with network protocols, data security, multithreading, and computer languages versus development environments. (LRW)

  1. [Extracorporeal shock-wave lithotripsy in polycystic kidneys].

    PubMed

    Martínez Sarmiento, M; Broseta Rico, E; Sanz Chinesta, S; García Reboll, L; Martín Abad, L; Jiménez Cruz, J F

    1994-01-01

    Presentation of 6 cases (8 renal units) of lithiasis in polycystic kidneys treated with extracorporeal shockwave lithotrity (ESWL). One patient required puncture of a compressing cyst, prior to ESWL, to facilitate the stones removal. No complications were seen in any of the cases. Therefore, stones in polycystic kidneys can be safely and effectively treated by ESWL.

  2. The complications of extracorporeal shockwave lithotripsy: management and prevention.

    PubMed

    Coptcoat, M J; Webb, D R; Kellett, M J; Fletcher, M S; McNicholas, T A; Dickinson, I K; Whitfield, H N; Wickham, J E

    1986-12-01

    Extracorporeal shockwave lithotripsy has been shown to be a safe and effective method of treating most upper urinary tract stones. Major complications, although few, include haemorrhage, septicaemia, "Steinstrasse" formation and cardiac arrhythmias. The experience from 600 consecutive cases is reviewed and methods of prevention are discussed.

  3. [Methods optimizing the efficiency of the extracorporeal shockwave lithotripsy (ESWL)].

    PubMed

    Bonev, K; Panchev, P; Simeonov, P

    2007-01-01

    The medicine science is in a progressive mode. One of the ever discussed problems is the stone kidney disease and the optimizing methods of its treatment. In this article the authors announced a new method of applying jelly, thus improving the efficiency of the Extracorporeal Shockwave Lithotripsy (ESWL).

  4. Root cause analysis following nephrectomy after extracorporeal shockwave lithotripsy (ESWL).

    PubMed

    Cahill, Katie; Cruz, Eneida; Guilbert, Mary Beth; Oser, Meg O'Toole

    2008-12-01

    An adverse event after a routine extracorporeal shockwave lithotripsy procedure set into motion a root cause analysis methodology to decipher why and how the event occurred and offer a solution to prevent it from happening again. The process of performing a root cause analysis is discussed in detail.

  5. The TOPSHOCK study: Effectiveness of radial shockwave therapy compared to focused shockwave therapy for treating patellar tendinopath - design of a randomised controlled trial

    PubMed Central

    2011-01-01

    Background Patellar tendinopathy is a chronic overuse injury of the patellar tendon that is especially prevalent in people who are involved in jumping activities. Extracorporeal Shockwave Therapy is a relatively new treatment modality for tendinopathies. It seems to be a safe and promising part of the rehabilitation program for patellar tendinopathy. Extracorporeal Shockwave Therapy originally used focused shockwaves. Several years ago a new kind of shockwave therapy was introduced: radial shockwave therapy. Studies that investigate the effectiveness of radial shockwave therapy as treatment for patellar tendinopathy are scarce. Therefore the aim of this study is to compare the effectiveness of focussed shockwave therapy and radial shockwave therapy as treatments for patellar tendinopathy. Methods/design The TOPSHOCK study (Tendinopathy Of Patella SHOCKwave) is a two-armed randomised controlled trial in which the effectiveness of focussed shockwave therapy and radial shockwave therapy are directly compared. Outcome assessors and patients are blinded as to which treatment is given. Patients undergo three sessions of either focused shockwave therapy or radial shockwave therapy at 1-week intervals, both in combination with eccentric decline squat training. Follow-up measurements are scheduled just before treatments 2 and 3, and 1, 4, 7 and 12 weeks after the final treatment. The main outcome measure is the Dutch VISA-P questionnaire, which asks for pain, function and sports participation in subjects with patellar tendinopathy. Secondary outcome measures are pain determined with a VAS during ADL, sports and decline squats, rating of subjective improvement and overall satisfaction with the treatment. Patients will also record their sports activities, pain during and after these activities, and concurrent medical treatment on a weekly basis in a web-based diary. Results will be analysed according to the intention-to-treat principle. Discussion The TOPSHOCK study is the

  6. Verapamil limits shockwave-induced renal tubular damage in vivo.

    PubMed

    Strohmaier, W L; Abelius, A; Billes, I; Grossmann, T; Wilbert, D M; Bichler, K H

    1994-08-01

    Previous investigations on Madin Darby Canine Kidney (MDCK) cells demonstrated the protective effect of verapamil against shockwave-induced tubular dysfunction. In the present study, we investigated whether verapamil is also protective against shockwave-induced damage in vivo. Male rates were randomly assigned to three groups: verapamil (N = 18) (Group I), control (N = 18) (Group II), or sham treatment (N = 4) (Group III). Groups I and II were treated with 500 shockwaves to each kidney with the Dornier MFL 5000 at 18 kV. Animals assigned to Group III received only anesthesics. Verapamil was given to the animals in Group I for 5 days starting 1 day before shockwave exposure. Urine was collected for 8 hours the day before and immediately, 1.7, and 28 days after shockwave exposure (SWE) for measurement of volume, osmolality, hemoglobin, protein, N-acetyl-beta-glucosaminidase (NAG), beta 2-microglobulin (beta 2M), sodium, and creatinine. Kidneys were perfused and removed for histologic study 1, 7, and 28 days after SWE in six animals of Groups I and II. Blood was taken in these rats (Day 1 after SWE) for the determination of creatinine and sodium and the calculation of the creatinine clearance (CCr) and the fractional excretion of sodium (FENa). After SWE, there was strong diuresis and significantly increased excretion of NAG and beta 2M in the controls, while urine osmolality decreased. These changes were significantly less pronounced in the verapamil-treated rats. The CCr was higher and FENa lower than in the latter group.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Effects of high-energy shockwaves on normal human fibroblasts in suspension.

    PubMed

    Kaulesar Johannes, E J; Sukul, D M; Bijma, A M; Mulder, P G

    1994-12-01

    To gain insight in the effects of shockwaves on human cells the relationship between the energy density and the number of shockwaves as well as their effect on suspensions of normal cells was studied. At energy densities of 0.37, 0.6, 0.78, and 1.20 mJ/mm2 fibroblasts were subjected to 50, 100, 250, 500, and 1,000 shockwaves. Each test was performed three times and one sample was used as control. A decrease in viability related to the logarithm of both the number (P = 0.0000) and the energy density (P = 0.001) of the shockwaves was statistically demonstrable 1 hr after the shockwave application. The energy density of the shockwaves has less influence on the viability than the number of applied shockwaves. Seeding of viable cells 1 hr after the shockwave application showed that the decrease in the 48-hr growth potential was statistically dependent of the number of applied shockwaves only (P = 0.0007). After 24 hr no difference in the 48-hr growth potential could be demonstrated between viable shockwave-treated cells and control cells. The literature as well as our own investigations in vitro and in vivo indicate that shockwaves have a logarithmic dose-dependent destructive effect on cells in suspension, but they also seem to have a dose-dependent stimulating influence on the healing process in damaged tissues. Due to the logarithmic relationship between the viability and both the number and energy density of the applied shockwaves it might be expected that even excessive numbers of high-energy-density shockwaves don't soon lead to total destruction of all cells in the suspension.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Ariel's Densely Pitted Surface

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This mosaic of the four highest-resolution images of Ariel represents the most detailed Voyager 2 picture of this satellite of Uranus. The images were taken through the clear filter of Voyager's narrow-angle camera on Jan. 24, 1986, at a distance of about 130,000 kilometers (80,000 miles). Ariel is about 1,200 km (750 mi) in diameter; the resolution here is 2.4 km (1.5 mi). Much of Ariel's surface is densely pitted with craters 5 to 10 km (3 to 6 mi) across. These craters are close to the threshold of detection in this picture. Numerous valleys and fault scarps crisscross the highly pitted terrain. Voyager scientists believe the valleys have formed over down-dropped fault blocks (graben); apparently, extensive faulting has occurred as a result of expansion and stretching of Ariel's crust. The largest fault valleys, near the terminator at right, as well as a smooth region near the center of this image, have been partly filled with deposits that are younger and less heavily cratered than the pitted terrain. Narrow, somewhat sinuous scarps and valleys have been formed, in turn, in these young deposits. It is not yet clear whether these sinuous features have been formed by faulting or by the flow of fluids.

    JPL manages the Voyager project for NASA's Office of Space Science.

  9. [Gd-DTPA-supported magnetic resonance tomographic perfusion follow-up of shockwave-treated tumors].

    PubMed

    Naegele, M; Goetz, A E; Gamarra, F; Lumper, W; Conzen, P F; Hahn, D; Brendel, W; Lissner, J

    1989-05-01

    The signal characteristics of 14 shockwave-treated and 14 solid control tumors were studied before and after injection of Gd-DTPA in an animal model. T1-weighted images of shockwave-treated tumors documented no significant signal intensity increase after contrast media injection in comparison with the untreated control tumors. The reduction of perfusion in shockwave-treated tumors can be documented in vivo by the signal intensity changes of the tumors after contrast media injection.

  10. Vibrational spectroscopy in high temperature dense fluids

    SciTech Connect

    Moore, D.S.; Schmidt, S.C.

    1992-01-01

    Coherent anti-Stokes Raman spectroscopy (CARS) in conjunction with a two-stage light-gas gun has been used to obtain vibrational spectra of shock-compressed liquid N{sub 2}, O{sub 2}, CO, and their mixtures, as well as liquid N{sub 2}O. The experimental spectra are compared to spectra calculated using a semiclassical model for CARS intensities to obtain vibrational frequencies, peak Raman susceptibilities, and linewidths. The derived spectroscopic parameters suggest thermal equilibrium of the vibrational populations is established in less than a few nanoseconds after shock passage. Vibrational temperatures obtained are compared to those derived from equation-of-state calculations. The variation of the vibrational frequency shift at pressure with species concentration in mixtures is investigated.

  11. [Biliary extracorporeal shockwave lithotripsy in the surgical treatment concept of cholelithiasis].

    PubMed

    Meiser, G; Heinerman, M; Boeckl, O

    1990-05-01

    Extracorporeal shock-wave lithotripsy (BESWL) using the "Obertisch" module Lithostar Plus (Siemens AG) was carried out in 100 patients, comprising a total of 189 gallbladder stones with a size range from 8 to 35 mm. Chenodeoxycholic and ursodeoxycholic acid was given as adjuvant litholytic therapy, beginning 14 days before treatment. 53% of the patients suffered from radiolucent solitary stones with an average size of 21 +/- 6 mm. 14% had more than 3 stones, another 12% had solitary stones with a small rim calcification. In 99 patients all stones could be disintegrated. In 90% we achieved a fragment size smaller than 5 mm, in 10% smaller than 8 mm. 68 patients were treated in a single session, in 32% a 2nd or 3rd treatment was necessary. In the average 4100 +/- 2200 shock-waves with energy level 9 (650 bar) were applied. During treatment 15 patients suffered from slight right kidney pain. In the following 48 hours after BESWL we observed a transitory significant elevation of transaminases (32%), urinary amylases without clinical symptoms (31%), bilirubin (31%) and white blood cells (71%). A microhematuria was seen in 33%, a macrohematuria in 2%. Post-BESWL sonographically we found a transitory edema of the gallbladder wall in 18%, in 15% a hydrops, in 10% a dilatation of the common bile duct and in 4% free fluid surrounding the gallbladder. After dismission 31% of the patients suffered from slight colicky pain. In 3 patients acute biliary pancreatitis was observed 4 and 8 weeks after BESWL which could be treated by EPT and endoscopic stone removal.

  12. [Extracorporeal shockwave lithotripsy for upper urinary tract stone].

    PubMed

    Lechevallier, E; Traxer, O; Saussine, C

    2008-12-01

    Extracorporeal shockwave lithotripsy (ESWL) is the fragmentation of stone by means of acoustic shockwaves created by an extracorporeal source. ESWL brakes the stone by spallation and squeezing. The optimal frequency for fragmentation is 1Hz. The initial power must be low, then progressively increased during the session. The contra-indications for ESWL are pregnancy, major deformities, severe obesity, aortic aneurism, uncontrolled coagulation disorders, untreated urinary infection, cardiac pacemaker. A stone density of 1000UH is a risk factor for fragmentation failure. The success rate for the kidney and the ureter is 60-80% and 80%, respectively. Stone clearance may be facilitated by alpha blockers. Asymptomatic and non-infected residual fragments less than 4mm must be followed-up annually.

  13. Extracorporeal shockwave therapy for avascular necrosis of femoral head.

    PubMed

    Wang, Ching-Jen; Cheng, Jai-Hong; Huang, Chung-Cheng; Yip, Han-Kan; Russo, Sergio

    2015-12-01

    The etiology of osteonecrosis of the femoral head (ONFH) is multifactorial. Treatment of ONFH is disease stage dependent. For early stages, femoral head preservation procedures are preferred including core decompression, muscle pedicle grafting and de-rotational osteotomy. Core decompression with bone grafting is considered the gold standard. However, the results are inconsistence and unpredictable. An effective non-invasive method of treatment is imperative. Recently, extracorporeal shockwave therapy (ESWT) has shown beneficial effects in ONFH. ESWT improves pain and function of the hip and regression of the ONFH lesion. ESWT is more effective than core decompression with or without bone grafting, cocktail therapy that combined HBO, ESWT and oral alendronate is shown effective for patients with early osteonecrosis. The purpose of the article is to review, update and summarize the clinical treatment of ONFH using shockwave therapy.

  14. [A year experience with extracorporeal shockwave lithotripsy of gallstones].

    PubMed

    Rothenbühler, J M; Beglinger, C; Meyer, B; Marx, A; Ackermann, C; Stalder, G A; Harder, F

    1990-04-21

    43 patients with symptomatic gallbladder stones were treated by extracorporeal shockwave lithotripsy and oral bile acids. In all patients the stones were successfully fragmented during the first lithotripsy session. 33 patients underwent 2-4 treatment sessions. In 16 out of 43 patients the stones disappeared within 7.9 months. The rate of stone dissolution was dependent on the number and size of stones. 3 patients required surgery because of frequent colic in one case, cholecystitis in one case and lack of cooperation in one case. No important side effects were noted except mild pancreatitis 3 weeks after lithotripsy in one patient. Results at this center of extracorporeal shockwave lithotripsy combined with oral bile acids indicate that this treatment may become an alternative to cholecystectomy in patients with a small number (less than 3) of stones not exceeding 30 mm in diameter.

  15. Mesoscale simulations of shockwave energy dissipation via chemical reactions

    NASA Astrophysics Data System (ADS)

    Antillon, Edwin; Strachan, Alejandro

    2015-02-01

    We use a particle-based mesoscale model that incorporates chemical reactions at a coarse-grained level to study the response of materials that undergo volume-reducing chemical reactions under shockwave-loading conditions. We find that such chemical reactions can attenuate the shockwave and characterize how the parameters of the chemical model affect this behavior. The simulations show that the magnitude of the volume collapse and velocity at which the chemistry propagates are critical to weaken the shock, whereas the energetics in the reactions play only a minor role. Shock loading results in transient states where the material is away from local equilibrium and, interestingly, chemical reactions can nucleate under such non-equilibrium states. Thus, the timescales for equilibration between the various degrees of freedom in the material affect the shock-induced chemistry and its ability to attenuate the propagating shock.

  16. Mesoscale simulations of shockwave energy dissipation via chemical reactions.

    PubMed

    Antillon, Edwin; Strachan, Alejandro

    2015-02-28

    We use a particle-based mesoscale model that incorporates chemical reactions at a coarse-grained level to study the response of materials that undergo volume-reducing chemical reactions under shockwave-loading conditions. We find that such chemical reactions can attenuate the shockwave and characterize how the parameters of the chemical model affect this behavior. The simulations show that the magnitude of the volume collapse and velocity at which the chemistry propagates are critical to weaken the shock, whereas the energetics in the reactions play only a minor role. Shock loading results in transient states where the material is away from local equilibrium and, interestingly, chemical reactions can nucleate under such non-equilibrium states. Thus, the timescales for equilibration between the various degrees of freedom in the material affect the shock-induced chemistry and its ability to attenuate the propagating shock. PMID:25725713

  17. Effects of explosive explosion shockwave pretreatment on sludge dewaterability.

    PubMed

    Chen, Dayong; Yang, Jun

    2012-09-01

    The potential benefits and mechanism of explosive explosion shockwave pretreatment on sludge dewatering treatments were investigated in this study. Water content of sludge cake after centrifugation was used to evaluate sludge dewaterability. Particle size, viscosity, turbidity, and micrograph were determined to explain the observed changes in the pretreatment process. The results indicated that the optimal pretreatment condition, generating the lowest water content of sludge cake, was 25 g explosive and 96.7% original sludge water content. This condition resulted in the reduced particle size and viscosity as well as increased turbidity. Particle size and viscosity significantly contributed to enhance sludge dewaterability. Micrograph investigation indicated that explosive explosion shockwave pretreatment could rupture sludge flocs, release physically bound water, and extracellular substances into the solution, consequently enhancing sludge dewaterability.

  18. Mesoscale simulations of shockwave energy dissipation via chemical reactions.

    PubMed

    Antillon, Edwin; Strachan, Alejandro

    2015-02-28

    We use a particle-based mesoscale model that incorporates chemical reactions at a coarse-grained level to study the response of materials that undergo volume-reducing chemical reactions under shockwave-loading conditions. We find that such chemical reactions can attenuate the shockwave and characterize how the parameters of the chemical model affect this behavior. The simulations show that the magnitude of the volume collapse and velocity at which the chemistry propagates are critical to weaken the shock, whereas the energetics in the reactions play only a minor role. Shock loading results in transient states where the material is away from local equilibrium and, interestingly, chemical reactions can nucleate under such non-equilibrium states. Thus, the timescales for equilibration between the various degrees of freedom in the material affect the shock-induced chemistry and its ability to attenuate the propagating shock.

  19. Do not treat staghorn calculi by extracorporeal shockwave lithotripsy alone!

    PubMed

    Delaney, C P; Creagh, T A; Smith, J M; Fitzpatrick, J M

    1993-01-01

    A review of 84 patients with triple phosphate (staghorn) calculi treated by extracorporeal shockwave lithotripsy (ESWL) revealed a 67% stone clearance at 6 months. Classification of calculi according to morphology showed a variation in stone clearance from 47 to 82%. A significant number of patients developed complications (25%) or required additional procedures (27%). ESWL monotherapy is not a suitable treatment option for most patients with staghorn calculi.

  20. Raman study of the shockwave effect on collagens.

    PubMed

    Cárcamo, José J; Aliaga, Alvaro E; Clavijo, R Ernesto; Brañes, Manuel R; Campos-Vallette, Marcelo M

    2012-02-01

    The Raman spectra (1800-200 cm(-1)) of isolated dried collagen types I and III were recorded at different times after shockwave (SW) application in aqueous media. SWs were applied in a single session. One week after the SW application the vibrational data analysis indicates changes in the conformation of the collagens; orientational changes are also inferred. During the next three weeks collagens tended to recover the conformation and orientation existing before SW application.

  1. Flexible cystoscopy as an adjunct to extracorporeal shockwave lithotripsy.

    PubMed

    Mark, S D; Gray, J M; Wright, W L

    1990-09-01

    Ancillary procedures associated with extracorporeal shockwave lithotripsy (ESWL) include placement and subsequent removal of double pigtail ureteric stents. A simple new technique has been developed for the insertion of these stents. Using the flexible cystoscope, the procedure is performed on an out-patient basis under local anaesthesia. Placement of the stents was successful in 30/34 patients and removal was successful in 14/14 patients.

  2. Laser-induced shockwave propagation from ablation in a cavity

    SciTech Connect

    Zeng Xianzhong; Mao Xianglei; Mao, Samuel S.; Wen, S.-B.; Greif, Ralph; Russo, Richard E.

    2006-02-06

    The propagation of laser-induced shockwaves from ablation inside of cavities was determined from time-resolved shadowgraph images. The temperature and electron number density of the laser-induced plasma was determined from spectroscopic measurements. These properties were compared to those for laser ablation on the flat surface under the same energy and background gas condition. A theoretical model was proposed to determine the amount of energy and vaporized mass stored in the vapor plume based on these measurements.

  3. Towards collisions of inhomogeneous shockwaves in AdS

    NASA Astrophysics Data System (ADS)

    Fernández, Daniel

    2015-07-01

    We perform a numerical simulation of the evolution of inhomogeneities with transverse profile in a collision of gravitational shockwaves in asymptotically anti-de Sitter spacetime. This constitutes a step closer towards an accurate holographic description of the thermalization of a strongly coupled plasma, which can model the dynamics of heavy ion collisions. The results indicate that the considered inhomogeneities typically become hydrodynamical earlier or at the same moment when hydrodynamics applies to the background, even though they decay slowly.

  4. A shockwave approach for web-based clinical motion analysis.

    PubMed

    Lemaire, Edward

    2004-01-01

    Advances in Internet connectivity and personal multimedia computing have created opportunities for integrating simple motion analysis into clinical practice. The Macromedia Shockwave environment provides tools for creating media-rich software that runs within a Web browser. For this project, clinical motion analysis software was created using Shockwave that can load digital video clips of a client's motion, step/shuttle/play through the clip, superimpose a grid over the video image, measure relative joint angles, scale to a linear factor, measure distances, and measure average velocities. After installing the Shockwave and Quicktime video plug-ins, the Motion Analysis Tools-Shockwave program runs directly from a Web page hyperlink. Program testing involved comparing angle measurements, linear distances, stride length, and walking speed among six video clips. The first three clips were of a transtibial prosthesis being carried through the field of view (640 x 480, 320 x 240, 320 x 240 enlarged to 640 x 480). The second set of three clips was of a metal square carried through the field of view. Average root mean square errors were 2.0 degrees for angle measures and 1.2 cm for length measures. Stride length standard deviation was 4.6 cm (mean length = 212.1 cm). Average walking speed standard deviation was 0.015 m/s (mean speed = 1.15 m/s). The test results were consistent with video motion analysis results and within an acceptable range for clinical design-making. This Web-based motion analysis approach provides a useful tool for ubiquitous, quantitative, clinical gait analysis.

  5. Efficacy of Extracorporeal Shockwave Therapy in Frozen Shoulder

    PubMed Central

    Vahdatpour, Babak; Taheri, Parisa; Zade, Abolghasem Zare; Moradian, Saeed

    2014-01-01

    Background: Frozen shoulder has always been considered important because of the impact on the quality-of-life and long period of illness. Therefore, the use of noninvasive and safe techniques that can speed up the healing process of the disease is important. Methods: This study was a randomized clinical trial study on patients suffering from frozen shoulder who were referred to Isfahan University of Medical Sciences hospitals in 2011 and 2012. A total of 36 patients were enrolled in the study. Eligible patients were allocated into two groups. Intervention group received extracorporeal shockwave therapy (ESWT) once a week for 4 weeks. The control group received sham shockwave therapy once a week for 4 weeks. On the follow-up period, changes in individual performance and the amount of pain and disability were assessed by the Shoulder Pain and Disability Index (SPADI) questionnaire and the range of motion changes were assessed by a goniometer. Data obtained were analyzed using SPSS software. Results: Variance analysis revealed a difference in the mean pain and disability score of the SPADI questionnaire, flexion, extension, and abduction, external rotation of involved shoulder between two groups before and after the shockwave therapy (P < 0.05). Improvement was more satisfactory in the intervention group, but the mean internal rotation did not differ significantly in two groups (P > 0.05). Conclusions: The use of ESWT seems to have positive effects on treatment, quicker return to daily activities, and quality-of-life improvement on frozen shoulder. PMID:25104999

  6. International Shock-Wave Database: Systematization of Experimental Data

    NASA Astrophysics Data System (ADS)

    Levashov, Pavel R.; Khishchenko, Konstantin V.; Lomonosov, Igor V.; Minakov, Dmitry V.; Zakharenkov, Alexey S.

    2011-06-01

    In this work, we announce the creation of the International Shock-Wave Database (ISWDB). Shock-wave and related dynamic material response data serve for calibrating, validating, and improving material models over very broad regions of the pressure-temperature-density phase space. Our objectives are (i) to develop a database on thermodynamic and mechanical properties of materials under conditions of shock wave and other dynamic loadings, selected related quantities of interest, and the meta-data that describes the provenance of the measurements and material models, and (ii) to make this database available internationally thru the Internet, in an interactive form. The development and operation of the ISWDB will be guided by input from a steering committee. The database will be installed on two mirrored web-servers, one in Russia and the other in USA. The database will provide access to original experimental data on shock compression, non-shock dynamic loadings, isentropic expansion, measurements of sound speed in the Hugoniot state, and time-dependent free-surface or window-interface velocity profiles. We believe that the ISWDB will be a useful tool for the shock-wave community.

  7. Dense with Sense

    NASA Astrophysics Data System (ADS)

    Aletras, Anthony H.; Ingkanisorn, W. Patricia; Mancini, Christine; Arai, Andrew E.

    2005-09-01

    Displacement encoding with stimulated echoes (DENSE) with a low encoding strength phase-cycled meta-DENSE readout and a two fold SENSE acceleration ( R = 2) is described. This combination reduces total breath-hold times for increased patient comfort during cardiac regional myocardial contractility studies. Images from phantoms, normal volunteers, and a patient are provided to demonstrate the SENSE-DENSE combination of methods. The overall breath-hold time is halved while preserving strain map quality.

  8. Mach reflection in a warm dense plasma

    SciTech Connect

    Foster, J. M.; Rosen, P. A.; Wilde, B. H.; Hartigan, P.; Perry, T. S.

    2010-11-15

    The phenomenon of irregular shock-wave reflection is of importance in high-temperature gas dynamics, astrophysics, inertial-confinement fusion, and related fields of high-energy-density science. However, most experimental studies of irregular reflection have used supersonic wind tunnels or shock tubes, and few or no data are available for Mach reflection phenomena in the plasma regime. Similarly, analytic studies have often been confined to calorically perfect gases. We report the first direct observation, and numerical modeling, of Mach stem formation for a warm, dense plasma. Two ablatively driven aluminum disks launch oppositely directed, near-spherical shock waves into a cylindrical plastic block. The interaction of these shocks results in the formation of a Mach-ring shock that is diagnosed by x-ray backlighting. The data are modeled using radiation hydrocodes developed by AWE and LANL. The experiments were carried out at the University of Rochester's Omega laser [J. M. Soures, R. L. McCrory, C. P. Verdon et al., Phys. Plasmas 3, 2108 (1996)] and were inspired by modeling [A. M. Khokhlov, P. A. Hoeflich, E. S. Oran et al., Astrophys J. 524, L107 (1999)] of core-collapse supernovae that suggest that in asymmetric supernova explosion significant mass may be ejected in a Mach-ring formation launched by bipolar jets.

  9. Vertebral fracture associated with shockwave lithotripsy in a patient with granulomatous spondylitis.

    PubMed

    Kazimoğlu, H; Mungan, M U; Kirkali, Z

    2001-09-01

    Extracorporeal shockwave lithotripsy (SWL) is an accepted treatment modality in the treatment of urinary stone disease. Many complications have been reported secondary to high-energy shockwaves, but the effects of SWL on the skeletal system have rarely been investigated. We represent the first case of a burst-type vertebral fracture after SWL in an elderly osteoporotic patient with granulomatous spondylitis.

  10. Atoms in dense plasmas

    SciTech Connect

    More, R.M.

    1986-01-01

    Recent experiments with high-power pulsed lasers have strongly encouraged the development of improved theoretical understanding of highly charged ions in a dense plasma environment. This work examines the theory of dense plasmas with emphasis on general rules which govern matter at extreme high temperature and density. 106 refs., 23 figs.

  11. Mechanisms of shockwave action in the human kidney.

    PubMed

    Roessler, W; Steinbach, P; Seitz, R; Hofstaedter, F; Wieland, W F

    1995-12-01

    The effects on the human kidney parenchyma of high-energy shockwaves (HESW) with different energy densities were examined. Kidneys of patients treated by radical nephrectomy for renal cell carcinoma were perfused with cold HTK solution immediately after nephrectomy and kept in hypothermia (8 degrees C) for a maximum of 4 hours. The tumor-free parenchyma was treated with 2000 shocks at energy outputs of 15 kV (16 MPa, 0.15 mJ/mm2), 17 kV (32 MPa, 0.25 mJ/mm2), 19 kV (50 MPa, 0.4 mJ/mm2), and 21 kV (65 MPa, 0.6 mJ/mm2) in an experimental electromagnetic shockwave system (Siemens Co., Erlanger, Germany). Resulting tissue effects were analyzed by histologic and immunohistochemical examinations and confocal laser scanning microscopy. Different sensitivities of cell components, blood vessels, and tubules were found. Laser scanning microscopy revealed nuclear alterations in the vicinity of the focus up to a distance of approximately 10 mm. Severe histologic changes were found in a smaller zone, while immunohistochemistry studies revealed negative collagen IV staining in an area of approximately 4 x 4 mm (all distances measured within the plane perpendicular to the acoustic axis). From these results, it can be concluded that HESW directly damage the tubules and the vascular system, which might explain the clinical changes after extracorporeal shockwave lithotripsy in human patients. The extent of these effects seems to be dependent on the applied energy.

  12. Ulnar Neuropathy After Extracorporeal Shockwave Therapy: A Case Report.

    PubMed

    Shim, Jae Seong; Chung, Sun G; Bang, Hyun; Lee, Hyuk Jin; Kim, Keewon

    2015-06-01

    Currently, extracorporeal shockwave therapy (ESWT) is widely used for treatment of various musculoskeletal disorders. We report a case of ulnar neuropathy secondary to the application of ESWT. A 48-year-old man was diagnosed with medial epicondylitis and underwent 2 sessions of ESWT. Immediately after the second session, he experienced paresthesia and weakness in the right hand. On physical examination, atrophy of the first dorsal interosseus and weakness of the abductor digiti minimi were observed. Electrophysiologic study demonstrated ulnar neuropathy at the elbow with severe partial axonotmesis. Our case report demonstrates that ESWT might cause or contribute to peripheral nerve injury at the site of application.

  13. A death due to perirenal hematoma complicating extracorporeal shockwave lithotripsy.

    PubMed

    Uemura, Koichi; Takahashi, Sayuri; Shintani-Ishida, Kaori; Nakajima, Makoto; Saka, Kanju; Yoshida, Ken-ichi

    2008-03-01

    Perirenal hematoma is an occasional complication of extracorporeal shockwave lithotripsy (ESWL) which does not usually require treatment. A 79-year-old woman died 23 h after ESWL. Forensic autopsy was performed to determine whether medical treatment contributed to her death. The cause of death was hemorrhagic shock due to massive hematoma from a ruptured small vein in the perirenal adipose capsule. No injury to other organs was found and the patient had neither coagulation abnormality nor venous disease. Perirenal hematoma can easily be diagnosed with abdominal sonography, if pain or symptoms of anemia develop. Doctors must be aware of the possibilities of severe renal hematomas after ESWL.

  14. Extracorporeal shockwave lithotripsy monotherapy for paediatric urinary tract calculi.

    PubMed

    Thornhill, J A; Moran, K; Mooney, E E; Sheehan, S; Smith, J M; Fitzpatrick, J M

    1990-06-01

    The role of extracorporeal shockwave lithotripsy (ESWL) in the management of paediatric urinary tract calculi was evaluated. The study group included 22 children (13 male, 9 female) with an age range of 2 to 13 years. The renal calculi, including staghorn and ureteric calculi, varied in size from 0.3 to 5 cm. Overall stone clearance at 3 months was 79% with a low incidence of complications (2 children required nephrostomy drainage for sepsis). ESWL is a non-invasive method of managing even complex stones in children of all ages, irrespective of size or position.

  15. Stone fragmentation pattern of piezoelectric shockwave lithotripsy in vitro.

    PubMed

    Grenabo, L; Hedelin, H; Mohsenvand, C; Rodin, L; Wang, Y H; Pettersson, S

    1998-06-01

    Whole stones (N = 64; largest diameter 5-15 mm) were treated in vitro with piezoelectric shockwaves using the Edap LT-01 lithotripter with 2.5 Hz at either 100% or 54% power. The number of fragments larger than 2 mm was counted after every 30 seconds. The stones were defined as totally broken when all fragments were < 2 mm. Total fragmentation time was correlated with the energy level and the size of the stone. The number of large fragments did not correlate with the energy level but rather with the original size of the stone.

  16. Renal milk of calcium: contraindication to extracorporeal shockwave lithotripsy.

    PubMed

    Heidenreich, A; Vorreuther, R; Krug, B; Moul, J W; Engelmann, U H

    1996-01-01

    Renal milk-of-calcium (MOC) cysts are rare findings, with only approximately 60 cases reported in the literature. The diagnosis depends on the demonstration of the typical "half-moon" configuration on horizontal beam radiography; classical ultrasound finding is a gravity-dependent, echogenic shadowy material in a renal cyst. The importance of the MOC syndrome lies in its recognition and differentiation from a renal stone in order to avoid unwarranted surgery or extracorporeal shock-wave lithotripsy (ESWL). We have encountered five patients with renal MOC and present the typical clinical and radiological features in order to facilitate differential diagnosis.

  17. Detection of tissue injury after extracorporeal shockwave lithotripsy of gallstones.

    PubMed

    Brody, J M; Siebert, W F; Cattau, E L; al-Kawas, F; Goldberg, J A; Zeman, R K

    1991-06-01

    We evaluated seven patients undergoing gallstone lithotripsy for evidence of hepatic or renal trauma after each of 10 lithotripsy treatments. Postlithotripsy magnetic resonance imaging (MRI) and sonography showed no evidence of hepatic or renal injury as compared with baseline studies. Four treatments resulted in sonographic evidence of gaseous hepatic microbubbles (analogous to "the bends") due to cavitation effects of the shockwaves. Three of these four treatments produced serum glutamicoxaloacetic transaminase and -pyruvic transaminase elevation. One patient had microscopic hematuria. Minimal tissue damage results from gallstone lithotripsy. MRI and ultrasound, performed after lithotripsy, appear to be less sensitive than transaminasemia in detecting this low-grade injury.

  18. Extracorporeal shockwave lithotripsy monotherapy for large renal calculi.

    PubMed

    Gleeson, M J; Griffith, D P

    1989-10-01

    Extracorporeal shockwave lithotripsy (ESWL) monotherapy with a Dornier HM3 lithotripter was used to treat 199 large (greater than or equal to 3 cm) renal calculi. Calculi were classified as solitary (29), multiple (152) or staghorn (18) with stone-free rates of 55.2, 39.5 and 55.6% respectively. The stone-free rate was not statistically related to stone size, site or multiplicity. Complications occurred in 24 patients (12.8%) and were more common with solitary and staghorn calculi. ESWL is not recommended as primary treatment for most patients with large renal calculi.

  19. Impact of shockwave lithotripsy on upper urinary tract calculi.

    PubMed

    Riehle, R A; Näslund, E B; Fair, W; Vaughan, E D

    1986-10-01

    Extracorporeal shock wave lithotripsy (ESWL) currently is performed in selected urologic centers to treat over 80 per cent of patients with symptomatic upper urinary tract calculi. This noninvasive technique utilizing shockwaves to disintegrate stones into sand-sized particles allows the patient to pass the particles with spontaneous urination and replaces most surgery or percutaneous endoscopy for stone removal. However, stone-free success rates must be individualized depending on stone position, stone size, and composition. Lithotripsy of renal stones prior to migration and proximal ureteral stones early in their symptomatic course may alter significantly the incidence of distal ureteral calculi requiring hospitalization, cystoscopy, or ureteroscopy.

  20. Acoustic cavitation generated by an extracorporeal shockwave lithotripter.

    PubMed

    Coleman, A J; Saunders, J E; Crum, L A; Dyson, M

    1987-02-01

    Evidence is presented of acoustic cavitation generated by a Dornier extracorporeal shockwave lithotripter. Using x-ray film, thin aluminum sheets, and relatively thick metal plates as targets, evidence of liquid jet impacts associated with cavitation bubble collapse was observed. The jet impact was violent enough to puncture thin foils and deform metal plates. Furthermore, numerous jet impacts were generated over a volume of greater than 200 cm3. It is likely that such violent cavitation will also occur in tissue, and observed biological effects (e.g. renal calculus disintegration and tissue trauma) may be related to cavitation damage.

  1. [Extracorporeal shockwave therapy for erectile dysfunction and Peyronie's disease].

    PubMed

    Zhu, Ji-Yin; Jiang, Rui

    2014-09-01

    Penile vascular endothelial damage, vasomotor dysfunction, and blood flow deficiency are the major causes of erectile dysfunction (ED). Current management of ED mostly depends on selective phosphodiesterase type 5- (PDE5) inhibitors, which fail for some ED patients. For Peyronie's disease-induced ED, surgical and physical therapies are used in addition to PDE5I medication, but frequently it is difficult to achieve satisfactory results. Recent studies show that the low-intensity extracorporeal shockwave therapy can promote angiogenesis and improve blood flow to the penis, which promises to be a novel effective therapy for ED and Peyronie's disease.

  2. Fiber-coupled optical pyrometer for shock-wave studies

    SciTech Connect

    Holmes, N.C. )

    1995-03-01

    We have developed a new optical pyrometer with unique advantages for shock-wave studies and for measurements of systems that are moving with respect to the detection system. Our pyrometer is fully fiber optic coupled. This completely eliminates any time-dependent imaging or aperture effects common to imaging pyrometers, and is simple to align and calibrate. The sensitivity is also higher than typical imaging systems used for shock experiments. The design is excellent for observations of time-varying phenomena. Detection is done with fast photomultiplier tubes with roughly 1 ns response. In addition, one may also include a streaked spectroscopic system, making this system ideal for fast spectroscopic studies.

  3. Focused extracorporeal shockwave therapy in Dupuytren's disease--a hypothesis.

    PubMed

    Knobloch, Karsten; Kuehn, Marie; Vogt, Peter M

    2011-05-01

    Dupuytren's disease is a progressive disease due to unknown causal agents or genetics. An epidemiological analysis of 566 cases in North Germany estimated that around 1.9 million Germans are suffering from Dupuytren's disease. Beside Dupuytren's disease, there are a number of further less common forms of progressive fibromatosis, such as knuckle pads, plantar fibromatosis or Peyronie's disease. Surgery in plantar fasciectomy yields to a 60% recurrence rate depending on the extent of the plantar fasciectomy. Peyronie's disease of the penis affects middle-aged men between 40 and 60 years with penile pain, curvature during erection and potential erectile dysfunction. In a clinical randomized-controlled trial in Peyronie's disease 2000 focused extracorporeal shock waves reduced pain significantly and improved erectile function and quality of life. We hypothesize that focused extracorporeal shock wave therapy is able to reduce Dupuytren's contracture, a fibromatosis of the palm and improve function. Given the fact that recurrence rate in Dupuytren's disease is high und unpredictable extracorporeal shockwave therapy as a non-invasive tool might be applicable both, in primary and secondary prevention of the progression as well as for treatment. As such we have planned a randomized-controlled trial (ClinicialTrials.gov, NCT01184586) studying the effect of high-energy focused extracorporeal shockwave therapy on patients suffering Dupuytren's disease with patient-related outcome measures such as the DASH score and the Michigan Hand Outcome Questionnaire (MHQ) as primary outcome parameters.

  4. Mesoscale simulations of shockwave energy dissipation via chemical reactions

    NASA Astrophysics Data System (ADS)

    Antillon, Edwin; Strachan, Alejandro

    2015-06-01

    We use a particle-based mesoscale model that incorporates chemical reactions at a coarse-grained level to study the response of materials under shockwave-loading conditions. An additional implicit variable (the particle size) is used to describe volume-reducing chemical reactions using an intra-molecular potential inspired by Transition State Theory, while the dynamics of the center-of-mass motion evolves according to inter-particle forces. The equations of motion are derived from a Hamiltonian and the model captures both: total energy conservation and Galilean invariance. We demonstrate that this model captures complex thermo-mechanical-chemical processes, and we use these features to explore materials with the capabilities to dissipate shocks-wave energy due to ballistic impacts. Our results characterize how the parameters of the chemical model affect shock-wave attenuation, and we elucidate on how the coupling between the different energy-transferring mechanisms influences nucleation of chemistry for conditions away from equilibrium.

  5. [Use of extracorporeal shockwave therapy (ESWT)in sports orthopedics].

    PubMed

    Steinacker, T; Steuer, M

    2001-06-01

    From 11/97 to 10/99 409 patients have been treated with the extracorporal shockwave therapy (ESWT) in the sport orthopaedic ambulance. An ultrasound controlled treatment was applied in the low and middle energy range, using energy densities of 0.09 to 0.36 mJ/mm2. The ESWT came into application as an operation avoiding procedure after exhausting the conventional conservative therapy measures. Among the 409 patients, 65 persons were competitive sportsmen. Besides the established indications for the application of the shock wave therapy, this method also has been applied with specific sport orthopaedic indications like achillodynia, patella-top-syndrome, medial shin-syndrome, morbus Schlatter or tendinosis of the shoulder. The results were collected three months after the application of the ESWT using a standardized questionnaire. The performed examination exhibits that for conservatively treated tendinoses of the competitive sportsmen, similarly good therapy results concerning the application of ESWT can be reached compared with the classical orthopaedic shockwave therapy. Therefore, for the treatment of a tendinosis, a shock wave therapy should always be taken into account to avoid long exercise and competition breaks due to operative interventions.

  6. Extracorporeal shockwave lithotripsy using ultrasonic imaging: urologists' experience.

    PubMed

    Kiely, E A; Ryan, P C; McDermott, T E; Butler, M R

    1989-07-01

    The EDAP LT.01 is a second generation shockwave lithotripter which employs ultrasound imaging and piezoelectric shockwave generation. We describe the first 12 months of its use in the treatment of urinary calculi by urologists with no previous practical experience of ultrasonography. A total of 406 calculi (359 renal and 47 ureteric) in 317 patients were treated. Analgesia or sedation was not routinely used and 59% of all treatments were performed as outpatient procedures. The clearance rate of renal calculi smaller than 1 cm was 81%, while that of calculi larger than 3 cm was 80% (mean clearance 77.5%). Lithotripsy of ureteric calculi following retrograde manipulation to a renal site resulted in 94.4% clearance compared with 39% for those treated at a ureteric site; 93% of 684 lithotripsy treatments were either painless or caused only mild pain. Our experience with imaging and treating urinary calculi with the EDAP LT.01 lithotripter has been excellent. Patients are treated effectively and inexpensively as out-patients without analgesia or sedation.

  7. [Intracorporeal shockwave lithotripsy using the neodymium YAG laser].

    PubMed

    Schmeller, N T; Hofstetter, A; Kriegmair, M; Frank, F; Wondrazek, F

    1989-09-10

    The problem of suitable energy transfer and conversion for intraureteral lithotripsy has not yet been solved satisfactorily. Laser-induced shockwave lithotripsy (LISL) appears to be a very promising solution to this problem. We report on initial clinical experience using a Q-switched Nd:YAG laser generating a shockwave on the metallic surface of an optomechanic coupler. This leads to the fine fragmentation of a urinary calculus situated close to or in contact with the coupler. Only minimal side effects occur in biological tissue. Further development of the coupler resulted in considerable increase of its fragmentation capability with no increase in side-effects. As a result, application under fluoroscopic control alone became possible, which appears adequate in approximately half of the cases. In the other half visual inspection via ureteroscopy is required. Laser-induced lithotripsy is the only technique that uses a flexible transmission system, results in the fine fragmentation of calculi, and is free of serious side effects on tissue, i.e. does not lead to perforation of the wall of the ureter.

  8. [Imaging procedures prior to the extracorporeal shockwave lithotripsy of gallstones].

    PubMed

    Schneider, H T; Ell, C; Benninger, J; Theobaldy, S; Friedel, N; Rödl, W; Heyder, N; Hahn, E G

    1991-01-25

    In order to determine whether cholecystography and computed tomography (CT) are capable of better gallstone characterization than conventional radiography alone, 91 patients (76 females, 15 males; mean age 47 +/- 12 years) with symptomatic single gallstones were studied prospectively prior to extracorporeal shock-wave lithotripsy with concomitant oral stone dissolution therapy. In addition, the value of oral cholecystography in demonstrating patency of the cystic duct was compared with ultrasound assessment of gallbladder function. Despite "negative" plain gallbladder radiographs in all patients, oral cholecystography showed significant stone calcification in 8 of the 91 patients and CT showed stone calcifications in 52 of the 91 patients. In 12 patients the maximum stone density was between 50 and 90 Hounsfield units, and in 40 patients it was more than 90 Hounsfield units. CT revealed ring-like calcification in the majority (79%) of these stones. Oral cholecystography showed satisfactory concentration of contrast medium in all patients, while ultrasonography of the gallbladder following a chemically defined test meal demonstrated contractility of more than 50% of initial volume in 69 patients and of less than 30% in 9 patients. Although oral cholecystography is a simple, readily available complication-free method, ultrasound assessment of gallbladder contraction is better for selecting patients for extracorporeal shock-wave lithotripsy. CT allows significantly better characterization of gallstones than oral cholecystography and conventional plain gallbladder radiography.

  9. Shockwave Processing of Composite Boron and Titanium Nitride Powders

    NASA Astrophysics Data System (ADS)

    Beason, Matthew T.; Gunduz, I. Emre; Mukasyan, Alexander S.; Son, Steven F.

    2015-06-01

    Shockwave processing of powders has been shown to initiate reactions between condensed phase reactants. It has been observed that these reactions can occur at very short timescales, resulting in chemical reactions occurring at a high pressure state. These reactions have the potential to produce metastable phases. Kinetic limitations prevent gaseous reactants from being used in this type of synthesis reaction. To overcome this limitation, a solid source of gaseous reactants must be used. An example of this type of reaction is the nitrogen exchange reaction (e.g. B + TiN, B + Si3N4 etc.). In these reactions nitrogen is ``carried'' by a material that can be then reduced by the second reactant. This work explores the possibility of using nitrogen exchange reactions to synthesize the cubic phase of boron nitride (c-BN) through shockwave processing of ball milled mixtures of boron and titanium nitride. The heating from the passage of the shock wave (pore collapse, plastic work, etc.) combined with thermochemical energy from the reaction may provide a means to synthesize c-BN. This material is based upon work supported by the Department of Energy, National Nuclear Security Administration, under Award Number(s) DE-NA0002377. National Defense Science & Engineering Graduate Fellowship (NDSEG), 32 CFR 168a.

  10. Laboratory Simulations of Supernova Shockwave Progagation and ISM Interaction

    SciTech Connect

    Hansen, J F; Edwards, M J; Robey, H F; Miles, A R; Froula, D; Gregori, G; Edens, A; Ditmire, T

    2003-08-29

    High Mach number shockwaves were launched in laboratory plasmas to simulate supernova shockwave propagation. The experiments were carried out at inertial fusion facilities using large lasers. Spherical shocks were created by focusing laser pulses onto the tip of a solid pin surrounded by ambient gas. Ablated material from the pin would rapidly expand and launch a shock through the surrounding gas. Planar shocks were created by ablating material from one end of a cylindrical shocktube. Laser pulses were typically 1 ns in duration with ablative energies ranging from <1 J to >4 kJ. Shocks were propagated through various plasmas, and observed at spatial scales of up to 5 cm using optical and x-ray cameras. Interferometry techniques were used to deduce densities, and emission spectroscopy data were obtained to infer electron temperatures. Experimental results confirm that spherical shocks are Taylor-Sedov, and that radiative shocks stall sooner than non-radiative shocks. Unexpected results include the birth of a second shock ahead of the original, stalling shock, at the edge of the radiatively preheated region. We have begun experiments to simulate the interaction between shocks and interstellar material (ISM), and the subsequent turbulent mixing. Comparisons between experimental data and numerical simulations of shock evolution, stall, second shock birth, and interstellar material (ISM) interaction will be presented.

  11. Shock-induced bubble collapse in a vessel: Implications for vascular injury in shockwave lithotripsy

    NASA Astrophysics Data System (ADS)

    Coralic, Vedran; Colonius, Tim

    2014-11-01

    In shockwave lithotripsy, shocks are repeatedly focused on kidney stones so to break them. The process leads to cavitation in tissue, which leads to hemorrhage. We hypothesize that shock-induced collapse (SIC) of preexisting bubbles is a potential mechanism for vascular injury. We study it numerically with an idealized problem consisting of the three-dimensional SIC of an air bubble immersed in a cylindrical water column embedded in gelatin. The gelatin is a tissue simulant and can be treated as a fluid due to fast time scales and small spatial scales of collapse. We thus model the problem as a compressible multicomponent flow and simulate it with a shock- and interface-capturing numerical method. The method is high-order, conservative and non-oscillatory. Fifth-order WENO is used for spatial reconstruction and an HLLC Riemann solver upwinds the fluxes. A third-order TVD-RK scheme evolves the solution. We evaluate the potential for injury in SIC for a range of pressures, bubble and vessel sizes, and tissue properties. We assess the potential for injury by comparing the finite strains in tissue, obtained by particle tracking, to ultimate strains from experiments. We conclude that SIC may contribute to vascular rupture and discuss the smallest bubble sizes needed for injury. This research was supported by NIH Grant No. 2PO1DK043881 and utilized XSEDE, which is supported by NSF Grant No. OCI-1053575.

  12. Side effects of high-energy shockwaves in the human kidney: first experience with model comparing two shockwave sources.

    PubMed

    Roessler, W; Wieland, W F; Steinbach, P; Hofstaedter, F; Thüroff, S; Chaussy, C

    1996-12-01

    The side effects of high-energy shockwaves (HESW) from two different sources on kidney parenchyma obtained from 10 patients treated by radical nephrectomy for renal cell carcinoma were examined. Immediately after nephrectomy, the kidneys were perfused with cold HTK solution and kept in hypothermia (8 degrees C) for a maximum of 4 hours. In five cases, the tumor-free parenchyma was treated at the upper or lower renal pole with 2000 shocks, energy output 21 kV, in an experimental electromagnetic shockwave system (Siemens Co., Erlangen). In the other five cases, the upper or lower poles were treated with 2000 shocks, energy output 24 kV, in an electrohydraulic spark gap system (MFL 5000; Dornier Medizintechnik, Germering). The resulting tissue defects were analyzed by histologic examinations. Changes after treatment with the electromagnetic system were found mainly in the tubules and midsized blood vessels in a well-defined focal area. Treatment with the electrohydraulic system was followed by tubular and glomerular lesions combined with vessel defects in a patchy pattern. The model is able to define the side effects of HESW in the human kidney and to test the side effects of different lithotripters.

  13. Aspects on how extracorporeal shockwave lithotripsy should be carried out in order to be maximally effective.

    PubMed

    Tiselius, Hans-Göran; Chaussy, Christian G

    2012-10-01

    The present review summarizes the most important considerations and steps for an optimal result of extracorporeal shockwave lithotripsy. The relationship between shockwave path, geometry and anatomical conditions is of utmost importance. Selection of appropriate treatment variables in terms of shockwave number, power and frequency, is an important prerequisite for proper disintegration and prevention of complications. Several supportive measures such as inversion therapy, citrate therapy, high diuresis, α-receptor antagonists, chemolysis and recurrence preventive measures are important parts of the management of this group of patients in order to avoid problems with residual fragments and new stone formation. Proper understanding of these factors as well as of the physics of shockwaves is necessary for a successful application of this non-invasive technology treatment concept.

  14. Tissue reactions under piezoelectric shockwave application for the fragmentation of biliary calculi.

    PubMed

    Ell, C; Kerzel, W; Heyder, N; Rödl, W; Langer, H; Mischke, U; Giedl, J; Domschke, W

    1989-05-01

    The tissue reactions that occurred during piezoelectric shockwaves for the fragmentation of biliary calculi were investigated in 10 surgically removed stone containing human gall bladders and in acute (six dogs) and chronic (six dogs) animal experiments. Before and after shockwave (500, 1500 or 3000) in the anaesthetised dogs, computed tomography (CT), magnetic imaging (MRI) and laboratory tests were done; treatment was carried out under continuous ultrasonographic control. Shockwave applications to the human gall bladders resulted in disintegration of the stones with no macroscopically or microscopically detectable tissue changes. In acute animal experiments, small haematomas were observed in all six animals at surfaces, but also inside the liver and gall bladder (max diameter 25 mm). Perforation or intra-abdominal or pleural bleeding did not occur. In chronic experiments, no macroscopic, and only slight microscopic residual lesions (haemosiderin deposits) were seen three weeks after shockwave. In almost all instances, the lesions were detected by CT, MRI, and ultrasonography, while laboratory tests were negative.

  15. Evaluation of basal membrane antibody (immunoglobulin G) formation after high-energy shockwave application in rats.

    PubMed

    Sarica, K; Türkölmez, K; Koşar, A; Alçiğir, G; Ozdiler, E; Göğüş, O

    1998-12-01

    To evaluate the immune pathologic effects of high-energy shockwave (HESW) application on glomerular and tubular basal membrane antibody (IgG) formation, an experimental study on rats has been performed. Following application of different numbers of shockwaves (100-200-500), the presence of antibody was examined with the direct immunofluorescent technique 2 weeks and 3 months postprocedure. Whereas specimens examined after 2 weeks showed antibody formation in only one animal (500 HESWs), being located in the tubular tissues, all treated kidneys demonstrated various degrees of antibody formation in both tubular and glomerular tissues after 3 months. Antibody formation had a close relation to the number of HESWs applied and the time of examination after shockwave application. Apart from the well-defined functional and morphologic side effects of shockwave therapy, the possibility of immunologic alterations after this form of therapy has to be evaluated thoroughly in both clinical and experimental studies.

  16. Shockwave therapy for patients with plantar fasciitis: a one-year follow-up study.

    PubMed

    Wang, Ching-Jen; Chen, Han-Shiang; Huang, Ting-Wen

    2002-03-01

    The effect of shockwave therapy was investigated in 79 patients (85 heels) with plantar fasciitis with one-year follow-up. There were 59 women and 20 men with an average age of 47 (range, 15-75) years. Each patient was treated with 1000 impulses of shockwave at 14 kV to the affected heel. A 100-point scoring system was used for evaluation including 70 points for pain and 30 points for function. The intensity of pain was based on a visual analogue scale from 0 to 10. The overall results were 75.3% complaint-free, 18.8% significantly better, 5.9% slightly better and none unchanged or worse. The effect of shockwave therapy seemed cumulative and was time-dependent. The recurrence rate was 5%. There were no device-related problems, systemic or local complications. Shockwave therapy is a safe and effective modality in the treatment of patients with plantar fasciitis.

  17. Deformation behavior and spall fracture of the Hadfield steel under shock-wave loading

    NASA Astrophysics Data System (ADS)

    Gnyusov, S. F.; Rotshtein, V. P.; Polevin, S. D.; Kitsanov, S. A.

    2011-03-01

    Comparative studies of regularities in plastic deformation and fracture of the Hadfield polycrystalline steel upon quasi-static tension, impact failure, and shock-wave loading with rear spall are performed. The SINUS-7 accelerator was used as a shock-wave generator. The electron beam parameters of the accelerator were the following: maximum electron energy was 1.35 MeV, pulse duration at half-maximum was 45 ns, maximum energy density on a target was 3.4·1010 W/cm2, shock-wave amplitude was ~20 GPa, and strain rate was ~106 s-1. It is established that the failure mechanism changes from ductile transgranular to mixed ductile-brittle intergranular one when going from quasi-static tensile and Charpy impact tests to shock-wave loading. It is demonstrated that a reason for the intergranular spallation is the strain localization near the grain boundaries containing a carbide interlayer.

  18. [Shockwave lithotripsy in gallbladder and bile duct calculi: indications and results].

    PubMed

    Paumgartner, G

    1990-01-01

    Extracorporeal shock-wave lithotripsy combined with adjuvant litholytic therapy (ursodeoxycholic acid and chenodeoxycholic acid) is a relatively safe and effective noninvasive therapy for selected patients with symptomatic radiolucent gallbladder stones. The best results (80% stone-free patients within 1 year) are obtained with radiolucent solitary stones with a diameter of less than 20 mm. Shock-wave lithotripsy achieves rapid clearance of stones in about 80% of patients with bile duct calculi in whom endoscopic procedures fail.

  19. Lateral epicondylitis: This is still a main indication for extracorporeal shockwave therapy.

    PubMed

    Thiele, S; Thiele, R; Gerdesmeyer, L

    2015-12-01

    Extracorporeal shockwave therapy (ESWT) is used in a number of indications in the medical field. A number of tendinopathies show good and excellent results due to evidence based medicine. The treatment of lateral epicondylitis is known to show conflicting results. This overview of the published RCT's on ESWT for lateral epicondylitis tries to show the reasons for this conflicting data-base and point out, why we think that this is still a main indication for extracorporeal shockwave therapy.

  20. Thermal loading of laser induced plasma shockwaves on thin films in nanoparticle removal

    SciTech Connect

    Varghese, Ivin; Zhou Dong; Peri, M. D. Murthy; Cetinkaya, Cetin

    2007-06-01

    Damage concerns, such as substrate/film material alterations, damage, and delamination of thin films, have become a central problem in sub-100 nm particle removal applications. In the laser induced plasma (LIP) removal technique both LIP shockwave and radiation heating are potential sources of thermomechanical damage. The specific objective of current study is to conduct a computational investigation of the LIP shockwave effect on the thermoelastic response of a thin chromium (Cr) film deposited on a quartz substrate and to identify the conditions leading to the onset of plastic film deformations. The experimentally characterized shockwave pressure and temperature (approximated from gas dynamic relations) were prescribed as boundary conditions in the computational analysis. From the shockwave arrival times for different travel distances, the shockwave radius as well as the velocity were obtained as a function of the shockwave propagation time. Radial (and circumferential) stresses, caused by thermal expansion of the Cr film, were most dominant and, hence, of damage concern. It is determined that the resultant temperature rise utilizing a 1064 nm Nd:yttrium-aluminum-garnet (YAG) laser (450 mJ) due to the film-shockwave interactions was not sufficiently high to initiate film and/or substrate damage. No material alteration/damage of the Cr film is predicted due to the temperature and pressure of LIP shockwaves at the firing distance of 2 mm, with a high strain rate gain factor of two (minimum), though damage was observed experimentally for 1064 nm Nd:YAG laser at the pulse energy of 370 mJ. Reported results indicate that the leading cause of observed thin film damage during nanoparticle removal is almost certainly radiation heating from the LIP core.

  1. Laser induced shockwaves on flexible polymers for treatment of bacterial biofilms.

    PubMed

    Navarro, Artemio; Taylor, Zachary D; Beenhouwer, David; Haake, David A; Gupta, Vijay; Grundfest, Warren S

    2011-01-01

    Bacterial biofilm-related infections are a burden on the healthcare industry. The effect of laser generated shockwaves through polycarbonate, a flexible polymer, is explored for its ability to generate high peak stresses, and also for its ability to conform to complex wound surfaces. Shockwave pulses in Al coated polycarbonate substrates and a resulting peak stress of greater than 60 MPa was measured which should provide sufficient pressure to kill bacteria.

  2. Extracorporeal shockwave therapy for shoulder lameness in dogs.

    PubMed

    Becker, Willem; Kowaleski, Michael P; McCarthy, Robert J; Blake, Cara A

    2015-01-01

    The purpose of this article was to describe the outcome of dogs with instability, calcifying, and inflammatory conditions of the shoulder treated with extracorporeal shockwave therapy (ESWT). Medical records for 15 dogs with lameness attributable to the shoulder that failed previous conservative management were retrospectively reviewed. ESWT was delivered to those dogs q 3-4 wk for a total of three treatments. Short-term, in-hospital subjective lameness evaluation revealed resolution of lameness in three of nine dogs and improved lameness in six of nine dogs available for evaluation 3-4 wk following the final treatment. Long-term lameness score via telephone interview was either improved or normal in 7 of 11 dogs (64%). ESWT may result in improved function based on subjective patient evaluation and did not have any negative side effects in dogs with lameness attributable to instability, calcifying, and inflammatory conditions of the shoulder.

  3. [Clinical relevance of extracorporeal shockwave lithotripsy (ESWL) in choledocholithiasis].

    PubMed

    Weiss, W; Türk, C; Brownstone, E; Hruby, W; Klose, W; Kölbl, C; Marberger, M; Tuchmann, A

    1989-09-29

    Primary endoscopic removal of bile duct stones is an established method of treatment. However, the extraction of stones is impossible in about 10% of cases despite successful endoscopic papillotomy and manual lithotripsy. Over a period of two years extracorporeal shock-wave lithotripsy (ESWL) was performed in 32 patients. Piezolith 2200, a second generation lithotripter was used, which requires neither analgesia nor anaesthesia for the patient. Localisation of the stones was carried out by means of a 3.5 MH 2 sector scanner. ESWL treatment was successful in 24 of 32 patients (75%). In 6 patients the bile duct stones were too large or too numerous and in 2 patients sonographic localisation was impossible. Out of a total of 131 patients with stones in the biliary tract only 9 (6.8%) needed surgery. Piezoelectric lithotripsy is a safe and effective adjunct procedure for the treatment of bile duct stones which were not extractable by endoscopy.

  4. Extracorporeal shockwave lithotripsy and litholytic therapy in cholelithiasis.

    PubMed

    Erdamar, I; Avci, G; Füzün, M; Harmancioğlu, O

    1992-03-01

    Extracorporeal shockwave lithotripsy (ESWL) and litholytic therapy were used in 100 patients over a period of 16 months. ESWL was carried out with a Lithostar Plus and chenodeoxycholic acid was used as the lytic agent, given until 3 months after complete disappearance of stones. Within a period of 8-12 months, stones disappeared completely in 82 per cent of the patients who had a single stone less than or equal to 20 mm in diameter and in 50 per cent of those with a single stone greater than 20 mm in size or with multiple stones. Complications requiring surgery developed in five patients: three had acute cholecystitis and two developed acute pancreatitis. Of the patients in whom complete stone clearance was achieved, two of 11 followed up developed recurrence of stones 4 months after cessation of lytic therapy.

  5. [Extracorporeal shockwave lithotripsy of gallstones. Retrospective view and perspectives].

    PubMed

    Adamek, H E; Riemann, J F

    1992-07-01

    Extracorporeal shock-wave lithotripsy (ESWL) is a non-invasive technique in gallstone management, which has been in clinical use since many years now. Exact patient selection provides considerable stone-free rates within a year. Side effects and complications are rare. The stone-recurrence rate is about 15% after two years, and thus lower compared to that after oral dissolution therapy alone. Until now, there is no reasonable medical therapy to prevent stone recurrence. Furthermore, ESWL is a suitable therapy for retained common bile duct stones. Although laparoscopic cholecystectomy has become established as a new, minimally invasive surgical method, ESWL will continue to be a successful technique for the treatment of thoroughly selected gallstone patients, who are looking for a non-invasive way to get rid of their biliary pain, but not of their gall bladder.

  6. Laser shockwave technique for characterization of nuclear fuel plate interfaces

    SciTech Connect

    Perton, M.; Levesque, D.; Monchalin, J.-P.; Lord, M.; Smith, J. A.; Rabin, B. H.

    2013-01-25

    The US National Nuclear Security Agency is tasked with minimizing the worldwide use of high-enriched uranium. One aspect of that effort is the conversion of research reactors to monolithic fuel plates of low-enriched uranium. The manufacturing process includes hot isostatic press bonding of an aluminum cladding to the fuel foil. The Laser Shockwave Technique (LST) is here evaluated for characterizing the interface strength of fuel plates using depleted Uranium/Mo foils. LST is a non-contact method that uses lasers for the generation and detection of large amplitude acoustic waves and is therefore well adapted to the quality assurance of this process. Preliminary results show a clear signature of well-bonded and debonded interfaces and the method is able to classify/rank the bond strength of fuel plates prepared under different HIP conditions.

  7. Laser Shockwave Technique For Characterization Of Nuclear Fuel Plate Interfaces

    SciTech Connect

    James A. Smith; Barry H. Rabin; Mathieu Perton; Daniel Lévesque; Jean-Pierre Monchalin; Martin Lord

    2012-07-01

    The US National Nuclear Security Agency is tasked with minimizing the worldwide use of high-enriched uranium. One aspect of that effort is the conversion of research reactors to monolithic fuel plates of low-enriched uranium. The manufacturing process includes hot isostatic press bonding of an aluminum cladding to the fuel foil. The Laser Shockwave Technique (LST) is here evaluated for characterizing the interface strength of fuel plates using depleted Uranium/Mo foils. LST is a non-contact method that uses lasers for the generation and detection of large amplitude acoustic waves and is therefore well adapted to the quality assurance of this process. Preliminary results show a clear signature of well-bonded and debonded interfaces and the method is able to classify/rank the bond strength of fuel plates prepared under different HIP conditions.

  8. Extracorporeal shockwave lithotripsy of gallstones. Possibilities and limitations.

    PubMed

    Vergunst, H; Terpstra, O T; Brakel, K; Laméris, J S; van Blankenstein, M; Schröder, F H

    1989-11-01

    Recently extracorporeal shockwave lithotripsy (ESWL) has been introduced as a nonoperative treatment for gallstone disease. Except for lung damage, no significant adverse effects of ESWL of gallbladder stones have been observed in animals. In clinical use ESWL of gallbladder stones is now confined to 15% to 30% of symptomatic patients. To achieve complete stone clearance, ESWL of gallbladder stones must be supplemented by an adjuvant therapy. ESWL of bile duct stones is highly effective and can be considered in patients in whom primary endoscopic or surgical stone removal fails. Second generation lithotriptors allow anesthesia-free (outpatient) treatments, but the clinical experience with most of these ESWL devices is still limited. The likelihood of gallbladder stone recurrence is a major disadvantage of ESWL treatment, which raises the issue of cost-effectiveness. ESWL for cholelithiasis is a promising treatment modality with good short-term and unknown long-term results.

  9. Extracorporeal shockwave therapy for urolithiasis with renal insufficiency.

    PubMed

    Bhatia, V; Biyani, C S; al-Awadi, K

    1995-01-01

    Management of urolithiasis with renal insufficiency poses a multidimensional nephrourological situation. Sixty-two patients of potentially reversible calculus obstructive nephropathy and azotemia were treated with extracorporeal shockwave lithotripsy (ESWL) on the Sieman's Lithostar. These patients were treated under sedoanalgesia after the initial therapeutic ureteral stenting. Satisfactory fragmentation was achieved in all the patients. The incidence of major complications was 3.2% with an 85% stone-free rate at 6 months. Pre- and post-ESWL hemodialysis was required in 14 and 3 patients, respectively. All patients had variable levels of improvement in the renal function. Proper selection of cases is mandatory for satisfactory outcome. The combination of ureteral stenting followed by phased ESWL represents an attractive alternative to traditional surgical management of stones with renal insufficiency.

  10. [Extracorporeal shockwave therapy in endoscopic therapy-refractory gallstones].

    PubMed

    Tudyka, J; Wechsler, J G; Kratzer, W; Janowitz, P; Stange, E F; Adler, G

    1992-12-22

    Extracorporeal shock-wave lithotripsy (ESWL) was undertaken in 36 patients (12 men, 24 women; mean age 70.9 +/- 2.4 years) with extra- or intrahepatic bile duct stones which could not be removed endoscopically. Stone fragmentation was successful in 32 patients with stones in the choledochal duct and in one with stones in the left hepatic duct. Fragmentation failed in two patients with stones in the left hepatic duct and one with stones in the cystic duct. 26 of the 36 patients were free of stone after spontaneous passage (n = 3) or after endoscopic removal of the residual concrements (n = 23). Complications occurred in only five patients during or after ESWL (cardiac arrhythmias, respiratory failure, pancreatitis, cholangitis).--These data point to ESWL being clearly preferable to surgical intervention in bile duct stones refractory to endoscopic treatment, especially in the elderly with an increased perioperative risk.

  11. [Extracorporeal shockwave lithotripsy on the Sonolith-3000 apparatus].

    PubMed

    Tkachuk, V N; Veroman, V Iu; Komiakov, B K; Bannikov, V V; Sapelkin, A V; Ivanov, A O; Iudkevich, B A; Kalashian, R K

    1991-01-01

    The authors observed 812 patients with nephrolithiasis who underwent 876 sessions of shock-wave lithotripsy on Sonolith-3000 lithotriptor supplied with an ultrasonic system of the stone localization. The size of nephroliths ranged from 0.7 to 4.2 cm. Large-size nephroliths required repeated sessions and pretreatment establishment of the stent. The procedure proceeded without anesthesia. Subsequent renal colic was reported in 126 (15.5%), an exacerbation of pyelonephritis in 45 (5.5%), subcapsular hematoma in 4 (0.5%) of the patients. 790 patients showed clinical response (97.3%), with a complete destruction of the stone in 446 (54.9%) and partial one in 344 (42.4%) cases. 27 subjects were treated in outpatient setting. According to the authors, lithotripsy is contraindicated in urinary tract obstruction below the stone, renal failure, chronic pyelonephritis in the active phase of inflammation, marked impairment of cardiac rhythm.

  12. [Shockwave treatment of therapy refractory soft tissue pain].

    PubMed

    Boxberg, W; Perlick, L; Giebel, G

    1996-11-01

    Extracorporal shock-wave application (ESWA) has been used in the treatment of stones located in the kidneys, bile, pancreas and the glandula parotis. In the last 2 years several studies have shown the benefit of ESWA in the treatment of soft-tissue disorders and tendinosis calcarea. To date, the exact mechanism is unknown. Local hyperemia following damage or afferent inhibition is discussed. The possibilities and indications of ESWA with respect to several syndromes are presented. The results show the benefit of ESWA in the treatment of chronic soft-tissue disorders without severe side effects. Some patients showed small subcutaneous hematomas and erosion of the skin when energies about 20 mJ were used. Forty-seven of 84 of the patients obtained complete relief; 24 patients showed a marked reduction in their complaints. In only 13 of 84 cases was the treatment unsuccessful.

  13. Laser shockwave technique for characterization of nuclear fuel plate interfaces

    NASA Astrophysics Data System (ADS)

    Perton, M.; Lévesque, D.; Monchalin, J.-P.; Lord, M.; Smith, J. A.; Rabin, B. H.

    2013-01-01

    The US National Nuclear Security Agency is tasked with minimizing the worldwide use of high-enriched uranium. One aspect of that effort is the conversion of research reactors to monolithic fuel plates of low-enriched uranium. The manufacturing process includes hot isostatic press bonding of an aluminum cladding to the fuel foil. The Laser Shockwave Technique (LST) is here evaluated for characterizing the interface strength of fuel plates using depleted Uranium/Mo foils. LST is a non-contact method that uses lasers for the generation and detection of large amplitude acoustic waves and is therefore well adapted to the quality assurance of this process. Preliminary results show a clear signature of well-bonded and debonded interfaces and the method is able to classify/rank the bond strength of fuel plates prepared under different HIP conditions.

  14. Stone recurrence after shockwave lithotripsy: possible enhanced crystal deposition in traumatized tissue in rabbit model.

    PubMed

    Sarica, K; Soygür, T; Yaman, O; Ozer, G; Sayin, N; Akbay, C; Küpeli, S; Yaman, L S

    1996-12-01

    To evaluate the possible traumatizing effect of high-energy shockwaves (HESW) on new stone formation as indicated by crystal deposition in the renal parenchyma, we performed an experimental study in 50 rabbits. During severe oxaluria induced by continuous ethylene glycol (0.75%) administration, animals in the first group (N = 15) received 500 to 1500 shockwaves. Animals in the second group (N = 15) underwent no specific therapy apart from ethylene glycol administration. In a third group of animals (N = 15), only shockwave administration was applied. Sham group animals constituted the last group in our study (N = 5). Three months after shockwave application, tissue sections obtained from treated and untreated kidneys were evaluated histopathologically under light and transmission electron microscopy (TEM) for the presence and degree of crystal deposition in the cortical parenchymal region subjected to HESW. Crystal deposition was evident in the intercellular region and intratubular parts of the parenchyma in animals subjected to HESW application, especially in those receiving relatively high (1000 or 1500) numbers of shockwaves. On the other hand, no crystal formation and deposition was detectable in animals undergoing only ethylene glycol therapy or shockwave administration alone. Sham group animals demonstrated no significant renal histopathology. The traumatic effects of HESW should be evaluated as a factor in new stone formation after SWL.

  15. Delayed stimulatory effect of low-intensity shockwaves on human periosteal cells.

    PubMed

    Tam, Kam-Fai; Cheung, Wing-Hoi; Lee, Kwong-Man; Qin, Ling; Leung, Kwok-Sui

    2005-09-01

    We investigated the effect of shockwaves on cells explanted from normal human periosteum to study the potential mechanisms of their responses and to determine suitable treatment settings. The cells were subjected to one shockwave treatment with systematic combinations of energy intensities (range, 0.05-0.5 mJ/mm) and number of shocks (range, 500-2000) whereas control cells received no treatment. The immediate effect on cell viability and the long-lasting effect on proliferation, viable cell number at Day 18, and mineralization at Day 35 were assessed. We observed an immediate dose-dependent destructive effect of shockwaves. Energy intensity and number of shocks contributed equally to viability. Total energy dose (intensity x number of shocks) was a better reference for determining the shockwave effect. We also found a long-term stimulatory effect on proliferation, viable cell number, and calcium deposition of human periosteal cells. At the same total energy dose, low-intensity shockwaves with more shocks (0.12 mJ/mm at 1250 shocks) were more favorable for enhancing cellular activities than high-intensity waves with fewer shocks (0.5 mJ/mm at 300 shocks). These findings document some of the biochemical changes of periosteal cells during shockwave treatments.

  16. Shockwave treatment for musculoskeletal diseases and bone consolidation: qualitative analysis of the literature.

    PubMed

    Kertzman, Paulo; Lenza, Mario; Pedrinelli, André; Ejnisman, Benno

    2015-01-01

    Shockwave treatment is an option within orthopedics. The exact mechanism through which shockwaves function for treating musculoskeletal diseases is unknown. The aim of this study was to make a qualitative analysis on the effectiveness of shockwave treatment among patients with musculoskeletal pathological conditions and pseudarthrosis. Searches were conducted in the Cochrane Library, Medline and Lilacs databases. Thirty-nine studies that reported using shockwave treatment for musculoskeletal diseases were found. Their results varied greatly, as did the types of protocol used. The studies that evaluated the effectiveness of shockwave treatment for lateral epicondylitis, shoulder tendinopathy, knee osteoarthrosis, femoral head osteonecrosis and trochanteric bursitis reported inconsistent results for most of their patients. Those that evaluated patients with calcifying tendinopathy, plantar fasciitis, Achilles tendinopathy, patellar tendinopathy and pseudarthrosis showed benefits. Shockwave treatment is a safe and non-invasive method for chronic cases in which conventional techniques have been unsatisfactory and should be used in association with other treatment methods for tendinopathy. Further quality studies are needed. PMID:26229889

  17. Shockwave treatment for musculoskeletal diseases and bone consolidation: qualitative analysis of the literature☆

    PubMed Central

    Kertzman, Paulo; Lenza, Mario; Pedrinelli, André; Ejnisman, Benno

    2015-01-01

    Shockwave treatment is an option within orthopedics. The exact mechanism through which shockwaves function for treating musculoskeletal diseases is unknown. The aim of this study was to make a qualitative analysis on the effectiveness of shockwave treatment among patients with musculoskeletal pathological conditions and pseudarthrosis. Searches were conducted in the Cochrane Library, Medline and Lilacs databases. Thirty-nine studies that reported using shockwave treatment for musculoskeletal diseases were found. Their results varied greatly, as did the types of protocol used. The studies that evaluated the effectiveness of shockwave treatment for lateral epicondylitis, shoulder tendinopathy, knee osteoarthrosis, femoral head osteonecrosis and trochanteric bursitis reported inconsistent results for most of their patients. Those that evaluated patients with calcifying tendinopathy, plantar fasciitis, Achilles tendinopathy, patellar tendinopathy and pseudarthrosis showed benefits. Shockwave treatment is a safe and non-invasive method for chronic cases in which conventional techniques have been unsatisfactory and should be used in association with other treatment methods for tendinopathy. Further quality studies are needed. PMID:26229889

  18. Shockwave treatment for musculoskeletal diseases and bone consolidation: qualitative analysis of the literature.

    PubMed

    Kertzman, Paulo; Lenza, Mario; Pedrinelli, André; Ejnisman, Benno

    2015-01-01

    Shockwave treatment is an option within orthopedics. The exact mechanism through which shockwaves function for treating musculoskeletal diseases is unknown. The aim of this study was to make a qualitative analysis on the effectiveness of shockwave treatment among patients with musculoskeletal pathological conditions and pseudarthrosis. Searches were conducted in the Cochrane Library, Medline and Lilacs databases. Thirty-nine studies that reported using shockwave treatment for musculoskeletal diseases were found. Their results varied greatly, as did the types of protocol used. The studies that evaluated the effectiveness of shockwave treatment for lateral epicondylitis, shoulder tendinopathy, knee osteoarthrosis, femoral head osteonecrosis and trochanteric bursitis reported inconsistent results for most of their patients. Those that evaluated patients with calcifying tendinopathy, plantar fasciitis, Achilles tendinopathy, patellar tendinopathy and pseudarthrosis showed benefits. Shockwave treatment is a safe and non-invasive method for chronic cases in which conventional techniques have been unsatisfactory and should be used in association with other treatment methods for tendinopathy. Further quality studies are needed.

  19. Developing A Laser Shockwave Model For Characterizing Diffusion Bonded Interfaces

    SciTech Connect

    James A. Smith; Jeffrey M. Lacy; Barry H. Rabin

    2014-07-01

    12. Other advances in QNDE and related topics: Preferred Session Laser-ultrasonics Developing A Laser Shockwave Model For Characterizing Diffusion Bonded Interfaces 41st Annual Review of Progress in Quantitative Nondestructive Evaluation Conference QNDE Conference July 20-25, 2014 Boise Centre 850 West Front Street Boise, Idaho 83702 James A. Smith, Jeffrey M. Lacy, Barry H. Rabin, Idaho National Laboratory, Idaho Falls, ID ABSTRACT: The US National Nuclear Security Agency has a Global Threat Reduction Initiative (GTRI) which is assigned with reducing the worldwide use of high-enriched uranium (HEU). A salient component of that initiative is the conversion of research reactors from HEU to low enriched uranium (LEU) fuels. An innovative fuel is being developed to replace HEU. The new LEU fuel is based on a monolithic fuel made from a U-Mo alloy foil encapsulated in Al-6061 cladding. In order to complete the fuel qualification process, the laser shock technique is being developed to characterize the clad-clad and fuel-clad interface strengths in fresh and irradiated fuel plates. The Laser Shockwave Technique (LST) is being investigated to characterize interface strength in fuel plates. LST is a non-contact method that uses lasers for the generation and detection of large amplitude acoustic waves to characterize interfaces in nuclear fuel plates. However the deposition of laser energy into the containment layer on specimen’s surface is intractably complex. The shock wave energy is inferred from the velocity on the backside and the depth of the impression left on the surface from the high pressure plasma pulse created by the shock laser. To help quantify the stresses and strengths at the interface, a finite element model is being developed and validated by comparing numerical and experimental results for back face velocities and front face depressions with experimental results. This paper will report on initial efforts to develop a finite element model for laser

  20. Dynamics of plasma expansion and shockwave formation in femtosecond laser-ablated aluminum plumes in argon gas at atmospheric pressures

    SciTech Connect

    Miloshevsky, Alexander; Harilal, Sivanandan S.; Miloshevsky, Gennady Hassanein, Ahmed

    2014-04-15

    Plasma expansion with shockwave formation during laser ablation of materials in a background gasses is a complex process. The spatial and temporal evolution of pressure, temperature, density, and velocity fields is needed for its complete understanding. We have studied the expansion of femtosecond (fs) laser-ablated aluminum (Al) plumes in Argon (Ar) gas at 0.5 and 1 atmosphere (atm). The expansion of the plume is investigated experimentally using shadowgraphy and fast-gated imaging. The computational fluid dynamics (CFD) modeling is also carried out. The position of the shock front measured by shadowgraphy and fast-gated imaging is then compared to that obtained from the CFD modeling. The results from the three methods are found to be in good agreement, especially during the initial stage of plasma expansion. The computed time- and space-resolved fields of gas-dynamic parameters have provided valuable insights into the dynamics of plasma expansion and shockwave formation in fs-pulse ablated Al plumes in Ar gas at 0.5 and 1 atm. These results are compared to our previous data on nanosecond (ns) laser ablation of Al [S. S. Harilal et al., Phys. Plasmas 19, 083504 (2012)]. It is observed that both fs and ns plumes acquire a nearly spherical shape at the end of expansion in Ar gas at 1 atm. However, due to significantly lower pulse energy of the fs laser (5 mJ) compared to pulse energy of the ns laser (100 mJ) used in our studies, the values of pressure, temperature, mass density, and velocity are found to be smaller in the fs laser plume, and their time evolution occurs much faster on the same time scale. The oscillatory shock waves clearly visible in the ns plume are not observed in the internal region of the fs plume. These experimental and computational results provide a quantitative understanding of plasma expansion and shockwave formation in fs-pulse and ns-pulse laser ablated Al plumes in an ambient gas at atmospheric pressures.

  1. Nonlinear Acoustics in Fluids

    NASA Astrophysics Data System (ADS)

    Lauterborn, Werner; Kurz, Thomas; Akhatov, Iskander

    At high sound intensities or long propagation distances at in fluids sufficiently low damping acoustic phenomena become nonlinear. This chapter focuses on nonlinear acoustic wave properties in gases and liquids. The origin of nonlinearity, equations of state, simple nonlinear waves, nonlinear acoustic wave equations, shock-wave formation, and interaction of waves are presented and discussed. Tables are given for the nonlinearity parameter B/A for water and a range of organic liquids, liquid metals and gases. Acoustic cavitation with its nonlinear bubble oscillations, pattern formation and sonoluminescence (light from sound) are modern examples of nonlinear acoustics. The language of nonlinear dynamics needed for understanding chaotic dynamics and acoustic chaotic systems is introduced.

  2. Laser-induced shockwave chromatography: a separation and analysis method for nanometer-sized particles and molecules.

    PubMed

    Nagahara, Tetsuhiko; Ichinose, Nobuyuki; Nakamura, Shinpei

    2011-04-01

    A microscopic chromatography has been developed where nanometer-size molecules or particles are separated according to their size by the laser-induced shockwave in a water-filled capillary. As the shockwave passed through the mixture of molecules/particles in solution, they move to the direction of the propagation of the shockwave. The distance from the point of shockwave generation depends on the particle size or molecular weight. This technique has some advantages compared to conventional chromatography, in terms of quick analysis of molecular weight and applicability to sticky and adsorbing polymers. Experimental results obtained for proteins, their aggregates, and inorganic nanoparticles are presented.

  3. Extended asymmetric hot region formation due to shockwave interactions following void collapse in shocked high explosive

    NASA Astrophysics Data System (ADS)

    Shan, Tzu-Ray; Wixom, Ryan R.; Thompson, Aidan P.

    2016-08-01

    In both continuum hydrodynamics simulations and also multimillion atom reactive molecular dynamics simulations of shockwave propagation in single crystal pentaerythritol tetranitrate (PETN) containing a cylindrical void, we observed the formation of an initial radially symmetric hot spot. By extending the simulation time to the nanosecond scale, however, we observed the transformation of the small symmetric hot spot into a longitudinally asymmetric hot region extending over a much larger volume. Performing reactive molecular dynamics shock simulations using the reactive force field (ReaxFF) as implemented in the LAMMPS molecular dynamics package, we showed that the longitudinally asymmetric hot region was formed by coalescence of the primary radially symmetric hot spot with a secondary triangular hot zone. We showed that the triangular hot zone coincided with a double-shocked region where the primary planar shockwave was overtaken by a secondary cylindrical shockwave. The secondary cylindrical shockwave originated in void collapse after the primary planar shockwave had passed over the void. A similar phenomenon was observed in continuum hydrodynamics shock simulations using the CTH hydrodynamics package. The formation and growth of extended asymmetric hot regions on nanosecond timescales has important implications for shock initiation thresholds in energetic materials.

  4. Long-term effects of extracorporeal shockwave therapy in chronic calcific tendinitis of the shoulder.

    PubMed

    Daecke, W; Kusnierczak, D; Loew, M

    2002-01-01

    Various short-term studies have demonstrated the effectiveness of extracorporeal shockwave therapy in the treatment of calcific tendinitis. To evaluate the long-term effects and any complications, the 4-year outcome was determined in a prospective study of 115 patients. One session (group A, n = 56) or two sessions (group B, n = 59) of high-energy shockwave therapy were administered to each patient. The 6-month results showed that the level of success achieved in pain relief and the Constant score was energy-dependent and that there were significant differences in radiologic changes between the groups. By 4 years after shockwave therapy, 20% of the entire patient population had undergone surgery on the involved shoulder. The effects of extracorporeal shockwave therapy not followed by any other therapy within the first 6 months were evaluated in 59% (n = 68) of the original 115 patients. Subjectively, 78% of patients in group A and 87% in group B thought the shockwave treatment had been successful. The Constant score increased from a mean of 45 before treatment to 88 in group A and 85 in group B after treatment. Radiologic changes were found in 93% of patients in each group. In conclusion, the failure rate after ESWT is high, but for 70% of the patients in this study, the treatment was successful and no long-term complications were seen.

  5. Extracorporeal shockwave therapy: A systematic review of its use in fracture management.

    PubMed

    Petrisor, Ba; Lisson, Selene; Sprague, Sheila

    2009-04-01

    Extracorporeal shockwave therapy is increasingly used as an adjuvant therapy in the management of nonunions, delayed unions and more recently fresh fractures. This is in an effort to increase union rates or obtain unions when fractures have proven recalcitrant to healing. In this report we have systematically reviewed the English language literature to attempt to determine the potential clinical efficacy of extracorporeal shockwave therapy in fracture management. Of 32 potentially eligible studies identified, 10 were included that assessed the extracorporeal shockwave therapy use for healing nonunions or delayed unions, and one trial was included that assessed its use for acute high-energy fractures. From the included, studies' overall union rates were in favor of extracorporeal shockwave therapy (72% union rate overall for nonunions or delayed unions, and a 46% relative risk reduction in nonunions when it is used for acute high-energy fractures). However, the methodologic quality of included studies was weak and any clinical inferences made from these data should be interpreted with caution. Further research in this area in the form of a large-scale randomized trial is necessary to better answer the question of the effectiveness of extracorporeal shockwave therapy on union rates for both nonunions and acute fractures.

  6. [Trigger points - Diagnosis and treatment concepts with special reference to extracorporeal shockwaves].

    PubMed

    Gleitz, M; Hornig, K

    2012-02-01

    The 70-year-old trigger point theory has experienced a growing scientific confirmation and clinical significance as a consequence of recent muscle pain research. The trigger point pain formation is caused by high levels of vasoneuroactive substances. Depending on intensity and duration of the muscle stimulus the central pain processing is modified and leads to characteristic referred pain patterns. The most effective conventional forms of treatment are aimed at a direct mechanical manipulation of the trigger point as are new forms of therapy with focused and radial shockwaves. By using high pressures the focused shockwaves in particular are suitable to provoke local and referred pain and thus simplify the trigger point diagnosis. The empirically found therapeutic effect of shockwaves on muscles is hypothetical and can be explained in analogy with validated reactions of shockwaves in non-muscle tissues. Overall, the shockwave therapy on muscles represents a confirmation and extension of the existing trigger point therapy. It seems to be suitable for treating functional muscular disorders and myofascial pain syndromes within the locomotor system.

  7. Extended asymmetric hot region formation due to shockwave interactions following void collapse in shocked high explosive

    DOE PAGES

    Shan, Tzu -Ray; Wixom, Ryan R.; Thompson, Aidan P.

    2016-08-11

    In both continuum hydrodynamics simulations and also multimillion atom reactive molecular dynamics simulations of shockwave propagation in single crystal pentaerythritol tetranitrate (PETN) containing a cylindrical void, we observed the formation of an initial radially symmetric hot spot. By extending the simulation time to the nanosecond scale, however, we observed the transformation of the small symmetric hot spot into a longitudinally asymmetric hot region extending over a much larger volume. Performing reactive molecular dynamics shock simulations using the reactive force field (ReaxFF) as implemented in the LAMMPS molecular dynamics package, we showed that the longitudinally asymmetric hot region was formed bymore » coalescence of the primary radially symmetric hot spot with a secondary triangular hot zone. We showed that the triangular hot zone coincided with a double-shocked region where the primary planar shockwave was overtaken by a secondary cylindrical shockwave. The secondary cylindrical shockwave originated in void collapse after the primary planar shockwave had passed over the void. A similar phenomenon was observed in continuum hydrodynamics shock simulations using the CTH hydrodynamics package. Furthermore, the formation and growth of extended asymmetric hot regions on nanosecond timescales has important implications for shock initiation thresholds in energetic materials.« less

  8. Dense Axion Stars

    NASA Astrophysics Data System (ADS)

    Mohapatra, Abhishek; Braaten, Eric; Zhang, Hong

    2016-03-01

    If the dark matter consists of axions, gravity can cause them to coalesce into axion stars, which are stable gravitationally bound Bose-Einstein condensates of axions. In the previously known axion stars, gravity and the attractive force between pairs of axions are balanced by the kinetic pressure. If the axion mass energy is mc2 =10-4 eV, these dilute axion stars have a maximum mass of about 10-14M⊙ . We point out that there are also dense axion stars in which gravity is balanced by the mean-field pressure of the axion condensate. We study axion stars using the leading term in a systematically improvable approximation to the effective potential of the nonrelativistic effective field theory for axions. Using the Thomas-Fermi approximation in which the kinetic pressure is neglected, we find a sequence of new branches of axion stars in which gravity is balanced by the mean-field interaction energy of the axion condensate. If mc2 =10-4 4 eV, the first branch of these dense axion stars has mass ranging from about 10-11M⊙ toabout M⊙.

  9. Warm dense crystallography

    NASA Astrophysics Data System (ADS)

    Valenza, Ryan A.; Seidler, Gerald T.

    2016-03-01

    The intense femtosecond-scale pulses from x-ray free electron lasers (XFELs) are able to create and interrogate interesting states of matter characterized by long-lived nonequilibrium semicore or core electron occupancies or by the heating of dense phases via the relaxation cascade initiated by the photoelectric effect. We address here the latter case of "warm dense matter" (WDM) and investigate the observable consequences of x-ray heating of the electronic degrees of freedom in crystalline systems. We report temperature-dependent density functional theory calculations for the x-ray diffraction from crystalline LiF, graphite, diamond, and Be. We find testable, strong signatures of condensed-phase effects that emphasize the importance of wide-angle scattering to study nonequilibrium states. These results also suggest that the reorganization of the valence electron density at eV-scale temperatures presents a confounding factor to achieving atomic resolution in macromolecular serial femtosecond crystallography (SFX) studies at XFELs, as performed under the "diffract before destroy" paradigm.

  10. DENSE MEDIUM CYCLONE OPTIMIZATON

    SciTech Connect

    Gerald H. Luttrell; Chris J. Barbee; Peter J. Bethell; Chris J. Wood

    2005-06-30

    Dense medium cyclones (DMCs) are known to be efficient, high-tonnage devices suitable for upgrading particles in the 50 to 0.5 mm size range. This versatile separator, which uses centrifugal forces to enhance the separation of fine particles that cannot be upgraded in static dense medium separators, can be found in most modern coal plants and in a variety of mineral plants treating iron ore, dolomite, diamonds, potash and lead-zinc ores. Due to the high tonnage, a small increase in DMC efficiency can have a large impact on plant profitability. Unfortunately, the knowledge base required to properly design and operate DMCs has been seriously eroded during the past several decades. In an attempt to correct this problem, a set of engineering tools have been developed to allow producers to improve the efficiency of their DMC circuits. These tools include (1) low-cost density tracers that can be used by plant operators to rapidly assess DMC performance, (2) mathematical process models that can be used to predict the influence of changes in operating and design variables on DMC performance, and (3) an expert advisor system that provides plant operators with a user-friendly interface for evaluating, optimizing and trouble-shooting DMC circuits. The field data required to develop these tools was collected by conducting detailed sampling and evaluation programs at several industrial plant sites. These data were used to demonstrate the technical, economic and environmental benefits that can be realized through the application of these engineering tools.

  11. Shock-wave cosmology inside a black hole

    PubMed Central

    Smoller, Joel; Temple, Blake

    2003-01-01

    We construct a class of global exact solutions of the Einstein equations that extend the Oppeheimer–Snyder model to the case of nonzero pressure, inside the black hole, by incorporating a shock wave at the leading edge of the expansion of the galaxies, arbitrarily far beyond the Hubble length in the Friedmann–Robertson–Walker (FRW) spacetime. Here the expanding FRW universe emerges be-hind a subluminous blast wave that explodes outward from the FRW center at the instant of the big bang. The total mass behind the shock decreases as the shock wave expands, and the entropy condition implies that the shock wave must weaken to the point where it settles down to an Oppenheimer–Snyder interface, (bounding a finite total mass), that eventually emerges from the white hole event horizon of an ambient Schwarzschild spacetime. The entropy condition breaks the time symmetry of the Einstein equations, selecting the explosion over the implosion. These shock-wave solutions indicate a cosmological model in which the big bang arises from a localized explosion occurring inside the black hole of an asymptotically flat Schwarzschild spacetime. PMID:12972640

  12. Developing a laser shockwave model for characterizing diffusion bonded interfaces

    SciTech Connect

    Lacy, Jeffrey M. Smith, James A. Rabin, Barry H.

    2015-03-31

    The US National Nuclear Security Agency has a Global Threat Reduction Initiative (GTRI) with the goal of reducing the worldwide use of high-enriched uranium (HEU). A salient component of that initiative is the conversion of research reactors from HEU to low enriched uranium (LEU) fuels. An innovative fuel is being developed to replace HEU in high-power research reactors. The new LEU fuel is a monolithic fuel made from a U-Mo alloy foil encapsulated in Al-6061 cladding. In order to support the fuel qualification process, the Laser Shockwave Technique (LST) is being developed to characterize the clad-clad and fuel-clad interface strengths in fresh and irradiated fuel plates. LST is a non-contact method that uses lasers for the generation and detection of large amplitude acoustic waves to characterize interfaces in nuclear fuel plates. However, because the deposition of laser energy into the containment layer on a specimen's surface is intractably complex, the shock wave energy is inferred from the surface velocity measured on the backside of the fuel plate and the depth of the impression left on the surface by the high pressure plasma pulse created by the shock laser. To help quantify the stresses generated at the interfaces, a finite element method (FEM) model is being utilized. This paper will report on initial efforts to develop and validate the model by comparing numerical and experimental results for back surface velocities and front surface depressions in a single aluminum plate representative of the fuel cladding.

  13. Shockwave Absorption using Network-forming Ionic glass

    NASA Astrophysics Data System (ADS)

    Lee, Jaejun; Yang, Ke; Moore, Jeffrey; Sottos, Nancy; MURI SWED Collaboration

    2015-06-01

    Network-forming ionic glasses composed of di-ammonium cations and citrate anions exhibit significant potential for dissipation of shock wave energy. The long alkyl side chains in the di-ammonium cation form a soft matrix, while the negatively charged heads of anions segregate into hard nanophase domains. Similar to polyurea, which has microphase separation of soft and hard domains, we hypothesize that shock wave dissipation of the ionic glass occurs by bond breaking in the hard domains and/or pressure-induced phase transition. By employing size-tunable alkyl side chains in the cations, we examine the effect of the relative soft domain size on energy dissipation. A series of thin film (ca. 50 μm) ionic glass specimens are subjected to laser-induced compressive stress waves and the transmitted response measured interferometrically. Structural changes of the ionic glass due to shock wave impact are characterized by x-ray diffraction. When compared directly to polyurea films of identical thickness and geometry, the ionic glass showed superior shock-wave mitigating performance. ONR MURI program.

  14. Extracorporeal shockwave lithotripsy of gallstones: clinical experience with 170 patients.

    PubMed

    Dion, Y M; Morin, J; Fraser, W

    1992-04-01

    Between Jan. 19, 1989 and Nov. 23, 1990, 170 patients with symptomatic cholelithiasis were evaluated for possible treatment by extracorporeal shockwave lithotripsy (ESWL). Thirty-one patients were not eligible for treatment, 28 (16%) because of nonvisualization of gallstones by ultrasonography and 3 (2%) because polyps were erroneously diagnosed on ultrasonography. Thirteen (8%) patients failed to comply with the protocol, leaving 126 patients for assessment. At the time of writing, the treatment success rate is 57% at 6 months and 69% at 9 months. Treatment failed in 21 (17%) patients because of unsatisfactory fragmentation in 16 (13%) patients, frequent biliary colic in 3 (2%) patients, acute pancreatitis in 1 (0.8%) patient and severe bile-salt-induced diarrhea in 1 (0.8%) patient. Complications included biliary colic (40 patients), mild diarrhea on bile salts (24 patients), severe diarrhea (1 patient), macroscopic hematuria (4 patients), acute pancreatitis (2 patients) and vagal shock (1 patient). This study demonstrates the effectiveness (87%) of the lithotripter in reducing gallstones to fragments 5 mm in diameter or smaller. However, complete disappearance of these fragments with adjuvant bile-salt therapy may take many months.

  15. Primary extracorporeal shockwave lithotripsy in management of large bladder calculi.

    PubMed

    Husain, I; el-Faqih, S R; Shamsuddin, A B; Atassi, R

    1994-06-01

    Large bladder calculi are often outside the range of treatment with conventional endoscopic lithotrites because of either anatomic factors or the mechanical limits of available instruments. Alternative methods of cystolithotripsy: ultrasonic, electrohydraulic, or laser, can prove time-consuming or even hazardous, so that open surgery is often the most expeditious option. We report our experience using Dornier HM3 extracorporeal shockwave lithotripsy (SWL) for initial bladder stone reduction preparatory to transurethral litholapaxy and definitive treatment of any underlying obstructive pathology. Primary cystolitholapaxy was judged impractical in these 24 patients (21 adults and 3 children) presenting 31 large bladder stones (mean size 35.6 mm). In all patients, primary transpelvic SWL was followed immediately by endoscopic evacuation of stone debris or cystolitholapaxy. In addition, 10 of the 24 patients (42%) underwent a definitive endoscopic operation for treatment of an underlying obstructive lesion at either the same or a follow-on session. Morbidity was minimal, and the mean hospital stay after the initial SWL treatment was 3.5 days. In our experience, Dornier SWL has proved invaluable in enabling cystolitholapaxy of very large bladder calculi that would otherwise require protracted and difficult endoscopic manipulation or open surgery.

  16. Extracorporeal shockwave lithotripsy or percutaneous nephrolithotomy for lower pole nephrolithiasis?

    PubMed

    Cass, A S

    1996-02-01

    A controversy has arisen as to whether the initial form of therapy for lower pole nephrolithiasis should be extracorporeal shockwave lithotripsy (SWL) or percutaneous nephrolithotomy (PCNL). We reviewed our results with 968 single lower pole stones treated by SWL and reviewed publications comparing SWL and PCNL for lower pole nephrolithiasis. In our cases, the stone-free rate was 71.2%, the rate of repeat treatment and post-treatment secondary procedures was 6.4%, the complication rate was 0.5%, and the hospital stay was less than 24 hours in 99.3% of patients. In published series of PCNL for lower pole nephrolithiasis, the stone free rate was 70.5% to 100%, repeat treatment rates were 4% to 62.5%, the complication rates were 13% to 38%, and the hospital stay was 3.1 to 6.1 days. The rates of recurrent stone disease with PCNL were 11% to 22%, similar to the rates after SWL. The percentage of renal urolithiasis patients with lower pole calculi since we started our unit in late 1986 has remained essentially constant at 38%. Although the stone-free rate with PCNL is higher than with SWL, the lower complication rate, lower repeat treatment/secondary procedure rate, the shorter hospital stay, and the similar recurrent stone rate with SWL make SWL more clinically effective as the primary therapy for lower pole calculi less than 2 cm in diameter.

  17. Risk factors predisposing to repeated extracorporeal shockwave lithotripsy.

    PubMed

    Bolton, D M; Lenaghan, D

    1994-01-01

    The Victorian Lithotripsy Service is geographically unique, representing the only Australian lithotripter for a 900-km radius and serving a patient population of over 3 million, and 26 accredited operator urologists. Because of distance and health service constraints few patients treated for renal calculi on this machine have the opportunity to seek additional treatment by extracorporeal shockwave lithotripsy (ESWL) elsewhere. The treatment histories of all patients who underwent ESWL at this center over a 4-year period were examined, with those patients who required ESWL on more than one occasion being identified and their treatment details reviewed. The retreatment rate was approximately 6%. In patients who required three or more ESWL treatments multiple calculi were present significantly more often than in the overall cohort (p < 0.05), and ESWL alone was ultimately successful in obtaining satisfactory stone fragmentation in only 62% of this group. In view of the high cost of repeated treatments by ESWL the applicability of this treatment method in cases of multiple calculi should be questioned. Initial undertreatment of calculi may also represent a significant factor in the retreatment of some radiopaque calculi.

  18. [Extracorporeal shockwave lithotripsy of the gallbladder: importance of selection criteria].

    PubMed

    Thorens, J; Schnegg, J F; Fasel, J; Deslarzes, C; Duvoisin, B; Schnyder, P; Gonvers, J J; Blum, A L

    1993-04-10

    In recent years, a number of alternatives to surgery for gallstones have been developed. Among them, extracorporeal shock-wave lithotripsy (ESWL) was promising, being non-invasive and risk-free. Nevertheless, its results vary according to the size, number and composition of the stones and according to the bile acids treatment used for fragment dissolution. To better evaluate the importance of these factors, we have widened the selection criteria currently used (1 to 3 non-calcified stones with a diameter below 30 mm) by including patients with large stones (up to 40 mm in diameter), multiple stones (up to 10 stones) and calcified stones. We also compared, for efficacy of fragment dissolution after ESWL, treatment by ursodeoxycholic acid alone as opposed to a mixture with chenodeoxycholic acid. Our results were (1) significant lessening of the fragmentation rate and of the number of gallbladders free of stones 1 year after ESWL when selection criteria are widened; (2) a mixture of ursodeoxycholic and chenodeoxycholic acids may favour fragment dissolution after ESWL compared to treatment by ursodeoxycholic acid alone.

  19. Different modes of fragmenting gallstones in extracorporeal shockwave lithotripsy.

    PubMed

    Nitsche, R; Schweinsberg, V; Klengel, H; Niedmann, P D; Fölsch, U R

    1993-03-01

    Forty radiolucent gallbladder stones from eight patients were fragmented in vitro by extracorporeal shockwave lithotripsy, using the electromagnetic lithotripter Lithostar Plus (Siemens) at five different energy levels. The stones were characterized by size, computed tomography (CT) density, and cholesterol content. The largest residual fragment was measured after every 20 to 100 shock waves. As expected, fewer shock waves were required to achieve fragmentation at higher energy levels. When stones of the same size were compared, there were remarkable differences in the number of shock waves required for fragmentation. These differences must originate in other properties of the stones than size and number. Two different modes of fragmentation were observed: in one group of stones small, flat fragments were chipped off at the beginning of fragmentation ('chipping mode'). These stones initially lost about 25% of their weight as small fragments (< 1 mm) before breaking centrally into some large fragments. In the other group stones initially lost only about 10% of their weight as small fragments (< 1 mm) at the beginning of fragmentation and early broke centrally into some large fragments ('breaking mode'). Stones showing the chipping mode were almost pure cholesterol stones (> 97%) and required significantly less shock waves than stones of the same size showing the breaking mode (cholesterol content, 64-94%). This mode of fragmentation could not be predicted by CT density.

  20. Extracorporeal shockwave for hip necrosis in systemic lupus erythematosus.

    PubMed

    Wang, C J; Ko, J Y; Chan, Y S; Lee, M S; Chen, J M; Wang, F S; Yang, K D; Huang, C C

    2009-10-01

    Patients with systemic lupus erythematosus (SLE) frequently received corticosteroid therapy, resulting in osteonecrosis of the femoral head (ONFH). Prior studies demonstrated the effectiveness of extracorporeal shockwave treatment (ESWT) for ONFH.. This study evaluated the effectiveness of ESWT for ONFH in patients with SLE. We studied 39 patients, including 15 patients with SLE (26 hips) and 24 controls (29 hips). To each affected hip we applied ESWT (6000 impulses at 28 kV in a single session). Patients were ambulated with partial weight bearing for 4-6 weeks. The primary endpoint was the need for hip replacement. The secondary endpoints were improvement in hip pain and function and image changes on X-ray and MRI. Patients received total hip replacement in 12% of patients with SLE and in 14% of controls (P = 0.802). There was no statistically significant difference in pain scores (0.86 vs. 0.89; P = 0.467) and function scores (89% vs. 91%; P = 0.194) between patients with SLE and controls. SLE response to ESWT for ONFH is comparable with ONFH in patients without SLE.

  1. Shockwave lithotripsy and endourological stone treatment in children.

    PubMed

    Lahme, Sven

    2006-04-01

    Urolithiasis in children is a rare disease in developed countries. Due to the particular anatomical conditions of the infant body, indications and results of the well-known treatment modalities, such as shockwave lithotripsy (SWL), ureteroscopy and PCNL, have to be determined. Experience in active stone treatment in children is very rare and only a limited number of papers are available. SWL can be performed only if focus size and treatment facilities are adapted to the size of the child. Miniaturization of ureteroscopes allows primary access to the infant upper urinary tract. Results, complications and morbidity of the treatment are similar to the results in adults. The main prerequisite for the primary endoscopic approach is the experience of the surgeon. PCNL should be performed as Mini-Perc. Percutaneous procedures show equal results and morbidity compared to the treatment of adults, in experienced hands. As two-thirds of infant stone patients have an underlying metabolic disorder, close cooperation of adult and pediatric urologists, nephrologists and radiologists is necessary in order to achieve good results in the treatment of infant stones.

  2. [Electromagnetic shockwave lithotripsy of gallstones. Preliminary clinical experiences].

    PubMed

    Neuhaus, H; Brandstetter, K; Hagenmüller, F; Gerhardt, P; Classen, M

    1990-01-26

    75 applications of extracorporeal electromagnetically produced shock-waves were performed on 40 patients with symptomatic gallbladder stones (27 women and 13 men; mean age 43.5 [25-69] years). The patients had up to three stones each, with a maximal diameter of 35 mm. Computed tomography revealed partial calcification of the stones in nine patients. Stone fragmentation succeeded in all patients. Two weeks after lithotripsy two patients were free of stone. Maximal fragment diameter, as measured by ultrasound, was less than 6 mm in 19 patients, 6-10 mm in 14, and 11-15 mm in five. At reexamination of 24 patients three months later, three additional patients were free of stone by ultrasound. No significant side effects were noted during the first 30 days after the procedure. But during further observation mild pancreatitis developed in two, while in one choledochal concrements caused obstructive jaundice which necessitated endoscopic papillotomy. These results demonstrate the effectiveness of this method of fragmenting gall-bladder stones.

  3. Control of cavitation activity by different shockwave pulsing regimes.

    PubMed

    Huber, P; Debus, J; Jöchle, K; Simiantonakis, I; Jenne, J; Rastert, R; Spoo, J; Lorenz, W J; Wannenmacher, M

    1999-06-01

    The aim of the study was to control the number of inertial cavitation bubbles in the focal area of an electromagnetic lithotripter in water independently of peak intensity, averaged intensity or pressure waveform. To achieve this, the shockwave pulses were applied in double pulse sequences, which were administered at a fixed pulse repetition frequency (PRF) of 0.33 Hz. The two pulses of a double pulse were separated by a variable short pulse separation time (PST) ranging from 200 micros to 1500 ms. The number and size of the cavitation bubbles were monitored by scattered laser light and stroboscopic photographs. We found that the number of inertial cavitation bubbles as a measure of cavitation dose was substantially influenced by variation of the PST, while the pressure pulse waveform, averaged acoustic intensity and bubble size were kept constant. The second pulse of each double pulse generated more cavitation bubbles than the first. At 14 kV capacitor voltage, the total number of cavitation bubbles generated by the double pulses increased with shorter PST down to approximately 400 micros, the cavitation lifespan. The results can be explained by cavitation nuclei generated by the violently imploding inertial cavitation bubbles. This method of pulse administration and cavitation monitoring could be useful to establish a cavitation dose-effect relationship independently of other acoustic parameters.

  4. Shock-wave dynamics during oil-filled transformer explosions

    NASA Astrophysics Data System (ADS)

    Efremov, V. P.; Ivanov, M. F.; Kiverin, A. D.; Utkin, A. V.

    2016-08-01

    This paper presents a numerical and experimental study of the shock-wave processes evolving inside a closed vessel filled with mineral oil. Obtained experimental Hugoniot data for oil are compared with the corresponding data for water. It is found that compression of mineral oil and water can be described by approximately the same Hugoniot over a wide pressure range. Such similarity allows the use of water instead of mineral oil in the transformer explosion experiments and to describe the compression processes in both liquids using similar equations of state. The Kuznetsov equation of state for water is adopted for a numerical study of mineral oil compression. The features of the evolution of shock waves within mineral oil are analyzed using two-dimensional numerical simulations. Numerical results show that different energy sources may cause different scenarios of loading on the shell. The principal point is the phase transition taking place at relatively high temperatures for the case of high-power energy sources. In this case, a vapor-gaseous bubble emerges that qualitatively changes the dynamics of compression waves and the pattern of loads induced on the shell. Taking into account the features of the process together with the concept of water-oil similarity, the present work presents a new approach for experimental modeling of transformer shell destruction using an explosion with given characteristics in a water-filled shell.

  5. [A 10-month experience with extracorporeal shockwave therapy of urolithiasis].

    PubMed

    García Sisamón, F; Ferrer Roda, J; Tudela Bañuls, O; Ferrer Bosch, L

    1990-01-01

    From November 1987 treatment of urinary lithiasis regardless location was initiated in our Service of extracorporal renal lithofragmentation using shockwaves. Up until August 1988 (10 months), 411 patients have been treated representing a total of 590 lithiasis and 699 sessions on which the present communication is based; treatment included calculus of various chemical composition, as well as different sizes and locations. Also the relationship between sex, age, number of waves, use of analgesia, hospital stay, etc, has been considered. Results obtained after a 2.5 months follow-up are: 60.34% fragments-free and 39.41% in expulsion stage. Monotherapy was chosen in 98% cases and multiple drug therapy in the remaining 2%. There has been no case of complementary open surgical therapy. Thus, we consider extracorporal renal lithofragmentation as the ideal treatment for urinary lithiasis, as long as the indication is correct. And we believe it to be the ideal treatment since it is a simple procedure, highly effective and with few complications. PMID:2239390

  6. [A 10-month experience with extracorporeal shockwave therapy of urolithiasis].

    PubMed

    García Sisamón, F; Ferrer Roda, J; Tudela Bañuls, O; Ferrer Bosch, L

    1990-01-01

    From November 1987 treatment of urinary lithiasis regardless location was initiated in our Service of extracorporal renal lithofragmentation using shockwaves. Up until August 1988 (10 months), 411 patients have been treated representing a total of 590 lithiasis and 699 sessions on which the present communication is based; treatment included calculus of various chemical composition, as well as different sizes and locations. Also the relationship between sex, age, number of waves, use of analgesia, hospital stay, etc, has been considered. Results obtained after a 2.5 months follow-up are: 60.34% fragments-free and 39.41% in expulsion stage. Monotherapy was chosen in 98% cases and multiple drug therapy in the remaining 2%. There has been no case of complementary open surgical therapy. Thus, we consider extracorporal renal lithofragmentation as the ideal treatment for urinary lithiasis, as long as the indication is correct. And we believe it to be the ideal treatment since it is a simple procedure, highly effective and with few complications.

  7. Numerical simulation of shock and bubble dynamics in shockwave lithotripsy

    NASA Astrophysics Data System (ADS)

    Colonius, Tim; Tanguay, Michel

    2002-11-01

    Theoretical evaluation of the efficacy of stone comminution (and potential for tissue damage) during shockwave lithotripsy requires knowledge of the complex stress fields associated with both the incident focussing shock and the dynamics of cavitation bubbles that it induces. While simple models from geometrical acoustics and subsequent modeling of spherical bubbles in isolation (Gilmore equation) can provide estimates, high-speed photography in vitro reveals a far more complex flow with bubble number densities that are sufficiently high such that collective effects associated with a cloud of bubbles are important. This talk will describe a modeling effort aimed at estimating stresses from these complex lithotripter generated flow fields. We compute the time-dependent, compressible, ensemble-averaged two-phase flow equations with a finite-difference scheme. Detailed modeling of the dynamics of bubbles (on the microscale) and high-order weighted essentially nonoscillatory shock-capturing schemes are employed. The model is compared to hydrophone and passive cavitation detection measurements, as well as qualitative comparison with high-speed photography. Finally, we explore collective bubble mechanisms ranging from defocusing and shielding of the stone (for high bubble densities in the focal region) to enhanced stresses due to concerted cloud collapse in a dual-pulse lithotripsy configuration. [Work supported by NIH P01 DK-43881 and NSF under grant CTS-9979258.

  8. Developing a laser shockwave model for characterizing diffusion bonded interfaces

    NASA Astrophysics Data System (ADS)

    Lacy, Jeffrey M.; Smith, James A.; Rabin, Barry H.

    2015-03-01

    The US National Nuclear Security Agency has a Global Threat Reduction Initiative (GTRI) with the goal of reducing the worldwide use of high-enriched uranium (HEU). A salient component of that initiative is the conversion of research reactors from HEU to low enriched uranium (LEU) fuels. An innovative fuel is being developed to replace HEU in high-power research reactors. The new LEU fuel is a monolithic fuel made from a U-Mo alloy foil encapsulated in Al-6061 cladding. In order to support the fuel qualification process, the Laser Shockwave Technique (LST) is being developed to characterize the clad-clad and fuel-clad interface strengths in fresh and irradiated fuel plates. LST is a non-contact method that uses lasers for the generation and detection of large amplitude acoustic waves to characterize interfaces in nuclear fuel plates. However, because the deposition of laser energy into the containment layer on a specimen's surface is intractably complex, the shock wave energy is inferred from the surface velocity measured on the backside of the fuel plate and the depth of the impression left on the surface by the high pressure plasma pulse created by the shock laser. To help quantify the stresses generated at the interfaces, a finite element method (FEM) model is being utilized. This paper will report on initial efforts to develop and validate the model by comparing numerical and experimental results for back surface velocities and front surface depressions in a single aluminum plate representative of the fuel cladding.

  9. [Extracorporeal shockwave lithotripsy in the treatment of common bile duct calculi].

    PubMed

    Amstrup, J H; Eldrup, J; Wille-Jørgensen, P A

    1995-04-10

    Fifteen patients with stones in the common bile duct, in whom treatment with endoscopic papillotomy and stone-extraction had been unsuccessful were treated with extracorporeal shockwave lithotripsy. Nine patients were stone-free after one or two sessions, and two patients after further endoscopic treatment. One patient achieved partial clearance and palliation. One patient had a choledochoduodenostomy performed due to ineffectiveness of the shockwave lithotripsy. Two patients, who were thought to have a stone, turned out to have neoplasma in the common bile duct. Complications were frequent but temporary and needed no treatment. We conclude that extracorporeal shockwave lithotripsy is a valuable and safe alternative in those cases where conventional endoscopic treatment has failed, and should be considered before operation, especially to old for high-risk patients.

  10. Sonographically-guided extracorporeal shockwave lithotripsy for pancreatic stones in patients with chronic pancreatitis.

    PubMed

    Schreiber, F; Gurakuqi, G C; Pristautz, H; Trauner, M; Schnedl, W

    1996-03-01

    Over a 2 year period, 10 patients with pancreatic stones due to alcohol induced chronic pancreatitis (proven by endoscopic retrograde pancreatography) underwent extracorporeal shockwave lithotripsy. Prior to shockwave therapy, all patients underwent endoscopic sphincterotomy. Targeting of shockwave lithotripsy was exclusively performed under sonographic control. All patients were treated with a second generation electrohydraulic spark gap lithotriptor and fragmentation of concrements could be achieved in all cases. Complete duct clearance was confirmed in seven patients by endoscopic retrograde pancreatography in one session, with endoscopic fragment extraction by basket and/or balloon catheter. In three patients, balloon dilation of concomitant strictures located in the head of the pancreas was performed prior to fragment extraction. All stone-free patients showed no further symptoms over the follow-up period of 12 months. Three patients in whom complete extraction of fragments was not successful experienced minor symptoms over the 12 month follow-up period.

  11. Donor-gifted allograft lithiasis: extracorporeal shockwave lithotripsy with over table module using the Lithostar Plus.

    PubMed

    Bhadauria, R P; Ahlawat, R; Kumar, R V; Srinadh, E S; Banerjee, G K; Bhandari, M

    1995-01-01

    Allograft lithiasis is usually secondary. Donor-graft lithiasis is a rare cause and only 5 cases have been reported. We report 2 such cases which are the first in the live-related transplantation programme. The pressing need to increase the donor pool in developing countries, safety of therapy in graft lithiasis coupled with minimal estimated risk of lithiasis recurrence in the donor are the main justifications for accepting calculi bearing kidney for transplantation. The 2 cases underwent extracorporeal shockwave lithotripsy using the overhead table module of the Lithostar Plus. The technical ease of lithotripsy using an on-line ultrasound module in these 'ectopically' placed kidneys is discussed. The effect of shockwaves on allograft function was studied by a pre- and post-renal scan (99Tc-DTPA) and serum creatinine. No adverse effect of shockwave on allograft function was noted both on short- and long-term follow-up.

  12. [The importance of computed tomography and magnetic resonance tomography in shockwave cholelithotripsy].

    PubMed

    Golder, W A; Tempel, U; Gmeinwieser, J

    1989-01-01

    With shockwave-lithotripsy a new method of therapy has been introduced, whose efficiency is essentially determined by that of the accompanying imaging diagnostics. This poses several new problems for the diagnostic radiologist. While sonography and conventional cholegraphy have an important place in connection with shockwave-lithotripsy, the role of computed tomography (CT) and magnetic resonance tomography (MRT) has not yet been established. According to our experiences and experimental data pre-interventional CT improves the accuracy for measurements of the calcium content of concrements and gives the best survey on the topography of the upper abdomen of patients with biliary concrements. MRT before lithotripsy does not yield important additional information. Applied after intervention it at least equals CT. Besides localization and description of the diseased gall-bladder the detection of complications with CT and MRT is one of the tasks of the radiologist in connection with shockwave-lithotripsy.

  13. 1D GAS-DYNAMIC SIMULATION OF SHOCK-WAVE PROCESSES VIA INTERNET

    SciTech Connect

    Khishchenko, K. V.; Levashov, P. R.; Povarnitsyn, M. E.; Zakharenkov, A. S.

    2009-12-28

    We present a Web-interface for 1D simulation of different shock-wave experiments. The choosing of initial parameters, the modeling itself and output data treatment can be made directly via the Internet. The interface is based upon the expert system on shock-wave data and equations of state and contains both the Eulerian and Lagrangian Godunov hydrocodes. The availability of equations of state for a broad set of substances makes this system a useful tool for planning and interpretation of shock-wave experiments. As an example of simulation with the system, results of modeling of multistep shock loading of potassium between polytetrafluoroethylene and stainless steel plates are presented in comparison with experimental data from Shakhray et al.(2005).

  14. Improving the antioxidant functionality of Citrus junos Tanaka (yuzu) fruit juice by underwater shockwave pretreatment.

    PubMed

    Kuraya, Eisuke; Nakada, Shina; Touyama, Akiko; Itoh, Shigeru

    2017-02-01

    Citrus junos Tanaka (yuzu) has a strong characteristic aroma, and hence, yuzu juice is used in a number of Japanese foods. We herein evaluated the functional compounds of yuzu juice to investigate whether underwater shockwave pretreatment affects its functionality. Employing the shockwave pretreatment at an increased discharge and energy of 3.5kV and 4.9kJ, respectively, resulted in an increase in the flavanone glycoside content and oxygen radical absorbance capacity (ORAC). The ORAC value of yuzu juice cultivated in Rikuzentakata increased approximately 1.7 times upon underwater shockwave pretreatment. The treatment method proposed herein exhibited reliable and good performance for the extraction of functional and antioxidant chemicals in yuzu fruits, and was comparable with traditional squeezing methods. The high applicability and reliability of this technique for improving the antioxidant functionality of yuzu fruit juice was demonstrated, confirming the potential for application to a wide range of food extraction processes.

  15. Improving the antioxidant functionality of Citrus junos Tanaka (yuzu) fruit juice by underwater shockwave pretreatment.

    PubMed

    Kuraya, Eisuke; Nakada, Shina; Touyama, Akiko; Itoh, Shigeru

    2017-02-01

    Citrus junos Tanaka (yuzu) has a strong characteristic aroma, and hence, yuzu juice is used in a number of Japanese foods. We herein evaluated the functional compounds of yuzu juice to investigate whether underwater shockwave pretreatment affects its functionality. Employing the shockwave pretreatment at an increased discharge and energy of 3.5kV and 4.9kJ, respectively, resulted in an increase in the flavanone glycoside content and oxygen radical absorbance capacity (ORAC). The ORAC value of yuzu juice cultivated in Rikuzentakata increased approximately 1.7 times upon underwater shockwave pretreatment. The treatment method proposed herein exhibited reliable and good performance for the extraction of functional and antioxidant chemicals in yuzu fruits, and was comparable with traditional squeezing methods. The high applicability and reliability of this technique for improving the antioxidant functionality of yuzu fruit juice was demonstrated, confirming the potential for application to a wide range of food extraction processes. PMID:27596400

  16. D Gas-Dynamic Simulation of Shock-Wave Processes via Internet

    NASA Astrophysics Data System (ADS)

    Khishchenko, K. V.; Levashov, P. R.; Povarnitsyn, M. E.; Zakharenkov, A. S.

    2009-12-01

    We present a Web-interface for 1D simulation of different shock-wave experiments. The choosing of initial parameters, the modeling itself and output data treatment can be made directly via the Internet. The interface is based upon the expert system on shock-wave data and equations of state and contains both the Eulerian and Lagrangian Godunov hydrocodes. The availability of equations of state for a broad set of substances makes this system a useful tool for planning and interpretation of shock-wave experiments. As an example of simulation with the system, results of modeling of multistep shock loading of potassium between polytetrafluoroethylene and stainless steel plates are presented in comparison with experimental data from Shakhray et al. (2005).

  17. Protective effect of verapamil on renal tissue during shockwave application in rabbit model.

    PubMed

    Yaman, O; Sarica, K; Ozer, G; Soygür, T; Kutsal, O; Yaman, L S; Göŭş, O

    1996-08-01

    Although extracorporeal shockwave lithotripsy (SWL) is the treatment of choice for symptomatic urinary calculi, it has been shown in number of studies that adverse effects of high-energy shockwaves may be encountered in short- and long-term follow-up. To evaluate the possible protective effect of verapamil administration on renal tissue, both magnetic resonance imaging (MRI) and histopathologic examination were performed after SWL in rabbits. Thirty-five animals were divided into three groups. The 15 animals in the first group were fed verapamil (0.1 mg/kg) for 3 days. Another 15 animals received no medication but underwent SWL, and the remaining 5 animals received anesthesia alone (sham group). The animals were then subdivided into three groups according to the shockwave number applied (1000, 15,000, or 2000) and the aforementioned evaluations were performed 24 hours and 3 months after the procedure. We found prominent histopathologic alterations in animals not receiving any medication before SWL. Persistence of these pathologic alterations during 3 months of follow-up indicated the importance of preservation of renal architecture during high-energy shockwave application. On the other hand, animals under verapamil medication prior to SWL demonstrated only a limited degree of histopathologic alteration. Demonstration of a normal histologic pattern after 3 months supported the preservation of tissue structure by such medication. No significant histopathologic alteration could be observed in the sham-group animals, as expected. Our study demonstrates that verapamil is protective against shockwave-induced renal tubular damage. Such medications may be useful to avoid the proven histopathologic and functional side effects of high-energy shockwaves.

  18. Fluid imbalance

    MedlinePlus

    ... fluid imbalance; Hypernatremia - fluid imbalance; Hypokalemia - fluid imbalance; Hyperkalemia - fluid imbalance ... of sodium or potassium is present as well. Medicines can also affect fluid balance. The most common ...

  19. [THE BONE DEFECT HEALING UNDER THE INFLUENCE OF RADIAL EXTRACORPOREAL SHOCK-WAVE THERAPY IN EXPERIMENT].

    PubMed

    Gertsen, G I; Se-Fey; Ostapchuk, R M; Lesovoy, A V; Zherebchuk, V V

    2016-03-01

    In experiment on 24 rabbits the processes of reparative osteogenesis in perforated defect of proximal tibial metaphysis under the influence of extracorporeal shock-wave therapy were studied. In accordance to data of clinical, roentgenological and morphological investiagations, conducted in terms 5, 15, 30 and 45 days of observation, there was established, that under the influence of extracorporeal shock-wave therapy in the bone marrow in the traumatic region a vasodilatation, as well as the blood cells exit from capillaries and sinusoid vessels with creation of massive regions of osseous endostal regenerate, guaranteeing the tibial integrity restoration, occurs. PMID:27514097

  20. Intraductal shock-wave lithotripsy in complicated common bile duct stones.

    PubMed

    Riemann, J F; Kohler, B; Weber, J; Schlauch, D

    1992-02-01

    Intracorporeal shockwave lithotripsy was performed in 36 patients with problematic common bile duct stones. All of the patients had undergone unsuccessful mechanical lithotripsy prior to this procedure. In 29 patients (80.6%), the stones were fragmented under cholangioscopic control and subsequently extracted with a Dormia basket. In seven patients, the procedure failed due to stone impaction or failure to intubate the common bile duct with a nasobiliary tube. No complications were observed. Cholangioscopically guided intracorporeal shockwave lithotripsy is a highly effective and safe procedure for the conservative treatment of complicated common bile duct stones.

  1. Epicardial shock-wave therapy improves ventricular function in a porcine model of ischaemic heart disease.

    PubMed

    Holfeld, Johannes; Zimpfer, Daniel; Albrecht-Schgoer, Karin; Stojadinovic, Alexander; Paulus, Patrick; Dumfarth, Julia; Thomas, Anita; Lobenwein, Daniela; Tepeköylü, Can; Rosenhek, Raphael; Schaden, Wolfgang; Kirchmair, Rudolf; Aharinejad, Seyedhossein; Grimm, Michael

    2014-05-19

    Previously we have shown that epicardial shock-wave therapy improves left ventricular ejection fraction (LVEF) in a rat model of myocardial infarction. In the present experiments we aimed to address the safety and efficacy of epicardial shock-wave therapy in a preclinical large animal model and to further evaluate mechanisms of action of this novel therapy. Four weeks after left anterior descending (LAD) artery ligation in pigs, the animals underwent re-thoracotomy with (shock-wave group, n = 6) or without (control group, n = 5) epicardial shock waves (300 impulses at 0.38 mJ/mm(2) ) applied to the infarcted anterior wall. Efficacy endpoints were improvement of LVEF and induction of angiogenesis 6 weeks after shock-wave therapy. Safety endpoints were haemodynamic stability during treatment and myocardial damage. Four weeks after LAD ligation, LVEF decreased in both the shock-wave (43 ± 3%, p < 0.001) and control (41 ± 4%, p = 0.012) groups. LVEF markedly improved in shock-wave animals 6 weeks after treatment (62 ± 9%, p = 0.006); no improvement was observed in controls (41 ± 4%, p = 0.36), yielding a significant difference. Quantitative histology revealed significant angiogenesis 6 weeks after treatment (controls 2 ± 0.4 arterioles/high-power field vs treatment group 9 ± 3; p = 0.004). No acute or chronic adverse effects were observed. As a potential mechanism of action in vitro experiments showed stimulation of VEGF receptors after shock-wave treatment in human coronary artery endothelial cells. Epicardial shock-wave treatment in a large animal model of ischaemic heart failure exerted a positive effect on LVEF improvement and did not show any adverse effects. Angiogenesis was induced by stimulation of VEGF receptors. Copyright © 2014 John Wiley & Sons, Ltd.

  2. Geometrical Optics of Dense Aerosols

    SciTech Connect

    Hay, Michael J.; Valeo, Ernest J.; Fisch, Nathaniel J.

    2013-04-24

    Assembling a free-standing, sharp-edged slab of homogeneous material that is much denser than gas, but much more rare ed than a solid, is an outstanding technological challenge. The solution may lie in focusing a dense aerosol to assume this geometry. However, whereas the geometrical optics of dilute aerosols is a well-developed fi eld, the dense aerosol limit is mostly unexplored. Yet controlling the geometrical optics of dense aerosols is necessary in preparing such a material slab. Focusing dense aerosols is shown here to be possible, but the nite particle density reduces the eff ective Stokes number of the flow, a critical result for controlled focusing. __________________________________________________

  3. Radiation awareness program for extracorporeal shockwave lithotripsy using Medstone lithotripters.

    PubMed

    Ugarte, R R; Cass, A S

    1998-06-01

    To determine the effectiveness of a radiation awareness program in reducing the radiation exposure to patients treated by a Medstone lithotripter, the exposure was calculated at the end of each extracorporeal shockwave (SWL) treatment using a table of measurements of the estimated entrance exposure rates 70 cm from the X-ray tube port. The results, related to stone size and patient weight, were distributed every month to each radiologic technologist, and a summary was sent regularly to the treating urologists. The doses before and after the introduction of the radiation awareness program were compared to determine the effectiveness of the program, and the chi-square test was used to determine statistical significance. The average calculated radiation exposure before and after introduction of the radiation awareness program was 16.39 rad and 8.26 rad, respectively, for patients with single renal stones; 17.31 rad and 9.02 rad, respectively, with single ureteral stones; 18.45 rad and 9.39 rad, respectively, with multiple renal stones; and 20.59 rad and 11.28 rad, respectively with multiple ureteral stones. These reductions in calculated radiation exposure were statistically significant only with multiple ureteral stones (P = 0.03). The only statistically significant differences in the stone-free rates, retreatment rates, and post-SWL secondary procedure rates before and after the introduction of the radiation awareness program were seen in the stone-free rates with single renal stones: 70% v 65%, respectively (P = 0.02); in the retreatment rates with single ureteral stones: 10% v 6%, respectively ( P < .01); and in the post-SWL secondary procedure rates with single renal stones: 4% v 2%, respectively (P = 0.01), and single ureteral stones: 7% v 4%, respectively (P = 0.05). The radiation awareness program resulted in a 51% reduction in the estimated radiation exposure to patients during SWL using Medstone lithotripters.

  4. Can aspirin prevent gallstone recurrence after successful extracorporeal shockwave lithotripsy?

    PubMed

    Adamek, H E; Buttmann, A; Weber, J; Riemann, J F

    1994-04-01

    Extracorporeal shockwave lithotripsy (ESWL) is a feasible procedure for the treatment of gallbladder stones in humans. Well-selected patients can achieve stone-free rates in a high percentage. With the gallbladder in situ, these patients are at risk of stone recurrence. There is considerable evidence that aspirin prevents cholesterol gallstone formation in animal models and may prevent gallstone recurrence in man. We attempted to clarify the risk of gallstone recurrence after successful piezoelectric lithotripsy in patients taking either low-dose aspirin or no medication. The first 45 patients shown to be completely free from stones after ESWL were randomized into two groups. One group received 100 mg aspirin daily; the other group did not receive any further medical therapy. Patients were further examined on an average of 19.6 months and 21.9 months, respectively. In the aspirin group the recurrence rate was 18.2%, whereas 21.7% of the patients in the control group developed recurrent stones. Seventy-eight per cent of these patients also had a recurrence of biliary pain. By life-table analysis we had, after a follow-up period of 24 months, a stone recurrence rate of 25% (+/- 11) in the aspirin group and 34% (+/- 14) in the control group. Our results indicate that recurrence prophylaxis remains one of the central questions in ESWL. In this preliminary study, 100 mg of aspirin daily was not able to reduce the recurrence rate after successful ESWL. Further studies will have to show whether higher doses of aspirin or other ways of preventing gallstone after ESWL are possible.

  5. Early experience with extracorporeal shockwave Dornier lithotriptor "compact".

    PubMed

    Hamdy, S; Morehouse, D D; Laporte, H; Elhilali, M M

    1995-06-01

    One of the latest developments in extracorporeal shockwave lithotripsy (SWL) is a combination of an electromagnetic energy source with an upgraded parallel online ultrasound imaging for localization. The device is compact, requiring no significant installation or site preparation. Furthermore, it increases the margin of safety of SWL by virtue of the continuous ultrasound monitoring. A hundred sessions of SWL were performed on 88 patients using the Dornier Compact machine. Ninety three renal units having an average of 1.7 stones were treated (two had upper ureteric stones). Of the 135 stones, 2 (1.5%) were radiolucent and 4 (3%) were of faint opacity. Intravenous sedation was used in all patients except one 13-year-old patient, who required general anesthesia. Patients received an average of 2409 shocks per session, and the maximum power setting ranged from 1 to 6 (average 4.7). A plain film was obtained immediately before and after treatment. Early adverse effects were uncommon, and all were mild. Patients were followed by plain films at 2 weeks and 3 months. In 35 sessions (25 solitary and 10 multiple stones), the stones were considered completely fragmented; in 63 sessions, the stones (43 solitary and 20 multiple) were judged to be partial fragmented; and 2 sessions (solitary stones) resulted in poor fragmentation. The mean (+/- SD) stone dimension in the group with complete fragmentation was 9 +/- 4.8 (range 2-24) mm, compared with 11 +/- 6.3 (range 2-38) mm in those with no or partial fragmentation (P = 0.0095). After 2 weeks, 23 of 69 systems (33%) were stone free, while 46 showed residual stones.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Piezoelectric shockwave lithotripters: differences in fragmentation efficiency in vitro.

    PubMed

    Schneider, H T; Weisshaar, E; Anderegg, A; Delmont, J P; Benattar, J M; Coendoz, S; Ell, C

    1993-05-01

    In a comparative assessment of the stone fragmentation efficacy of different piezoelectric lithotripters 72 human gallstones consisting of 24 sets of 3 stones each were disintegrated in vitro using the Piezolith 2300, the EDAP LT.01, and the Therasonic. On the basis of the maximum diameter the calculi were divided into group A (6-15 mm; n = 3 x 16) and group B (16-25 mm; n = 3 x 8) and were treated by using the maximum energy setting of each lithotripter (Piezolith 2300: setting 4, high power; EDAP LT.01: 95%; Therasonic: setting 7). Shockwave application was terminated when the residual fragments measured < or = 4 mm or after a total number of 6000 pulses. With the Piezolith 2300 all calculi could be disintegrated into fragments < or = 4 mm. In contrast, fragmentation was not successful, even after 6000 applied pulses, in the case of 2 and 6 stones when using EDAP LT.01 and the Therasonic lithotripters, respectively. With the remaining concrements of group A (n = 3 x 11) the fragmentation end point was achieved after a lower number of pulses when the Piezolith 2300 (median, 250 pulses; range, 50-500 pulses) was used than with the EDAP LT.01 (1000; 150-2500; p < 0.01) and the Therasonic lithotripters (2750; 750-5500; p < 0.01). Similar results were obtained for group B (n = 3 x 6): the Piezolith 2300 required fewer pulses (200; 100-1250) than the EDAP LT.01 (1000; 500-1000; p < 0.05) and the Therasonic (2000, 500-4000; p < 0.05) units.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. When should one perform shockwave lithotripsy for lower caliceal stones?

    PubMed

    Ilker, Y; Tarcan, T; Akdas, A

    1995-12-01

    Extracorporal shockwave lithotripsy of lower caliceal stones is often unrewarding because of the difficulty of passing stone fragments. We report our results in SWL of lower pole stones in 219 patients and compare them with the results of SWL of middle (82 patients) and upper pole (85 patients) stones. The stone-free rate of SWL monotherapy was found to be 59%, 77%, and 64% in lower, middle, and upper caliceal stones, respectively. In lower pole stones, SWL was unsuccessful in 41% of the patients, of whom 9% had minimal residual asymptomatic stones (less than 4 mm in greatest diameter). In comparison with the results of percutaneous nephrolithotomy (PCN) of lower pole urolithiasis in the literature, SWL was unsuccessful in large stones, with stone-free rates of 13% and 0 when the stone size was 3 to 4.9 cm2 and > 5 cm2, respectively. A stone-free rate of 82% when the stone burden was < 1 cm2 is similar to the PCN results of other centers, suggesting that SWL may be the first choice of treatment in lower pole stones of this size. We achieved a stone-free rate of 59% when the stone size was between 1 and 3 cm2, which is lower than the stone-free rates of PCN in the literature. In spite of its lower stone-free rates, SWL, with its lower morbidity, may still be considered an acceptable treatment modality in this range of moderate stone burden, especially when there is a patient desire for conservative treatment.

  8. Molecular changes after shockwave therapy in osteoarthritic knee in rats

    NASA Astrophysics Data System (ADS)

    Wang, C.-J.; Sun, Y.-C.; Wu, C.-T.; Weng, L.-H.; Wang, F.-S.

    2016-01-01

    This study investigated the molecular changes of DKK-1, MMP13, Wnt-5a and \\upbeta -catenin after extracorporeal shockwave therapy (ESWT) in anterior cruciate ligament transected (ACLT) osteoarthritic (OA) knee in rats. 27 male Spraque-Dawley rats were divided into three groups. Group I was the control one and received sham knee arthrotomy but no ACLT or ESWT. Group II underwent ACLT, but no ESWT. Group III underwent ACLT and received ESWT. The animals were killed at 12 weeks, and the harvested knee specimens were subjected to histopathological examination and immunohistochemical analysis. Radiographs of the knees were obtained at 0 and 12 weeks. At 12 weeks, radiographs of group II showed more arthritic changes with formation of osteochondral fragments, whereas very subtle arthritis was noted in groups I and III. In histopathological examination, group II showed a significant increase of Mankin score and a decrease of subchondral bone as compared to groups I and III. Group III showed a significant decrease of Mankin score and an increase of subchondral bone, with the data comparable to group I. In immunohistochemical analysis, group II showed significant increases of DKK-1 and MMP13 and decreases of Wnt-5a and \\upbeta -catenin in articular cartilage and subchondral bone as compared to groups I and III. Group III showed significant decreases of DKK-1 and MMP13 and increases of Wnt-5a and \\upbeta -catenin, with the data comparable to group I. In conclusion, the application of ESWT causes molecular changes that are consistent with the improvement in subchondral bone remodeling and chondroprotective effect in ACLT OA knees in rats.

  9. [Use of extracorporeal shockwave lithotripsy for kidney calculi].

    PubMed

    Trapeznikova, M F; Dutov, V V

    2004-01-01

    278 patients with coral nephrolithiasis were examined in 1990-2003. Extracorporeal shock-wave lithotripsy was made in 46 (16.5%) patients with 48 coral stones (mean age 48.2 +/- 18.3 years) as a basic treatment. The length of the concrement was 4.9 +/- 1.8 cm, width 3.8 +/- 1.4 cm, a relative area 19.72 +/- 13.01 cm2. All the patients have initially undergone internal drain of the kidney by a catheter (n = 13) or stent (n = 33). Each lithotripsy session included, on the average, 2882 +/- 318 impulses (17-19 kV). The number of high-energy impulses per a session comprised 342 +/- 23. A total number of the sessions reached 3.4 +/- 1.55. Initial destruction of the concrement requires 1.6 +/- 0.6 sessions in 10144 +/- 1081.2 impulses per one patient including 1436 +/- 96.6 high-energy impulses. One procedure comprises 2-3 sessions of lithotripsy with a 5-7 day interval. The results were assessed at discharge after the first session and 6 months later, the degree of stones elimination from the kidney, complications, manipulations to manage the complications. At discharge after 3 lithotripsy sessions recovery was achieved only in 3 out of 46 (6.52%) patients. Six months later the fragments eliminated in 26.1% (12 of 46 patients). Monolithotripsy caused complications in 13 patients. Additional manipulations made up 65.2%. Inefficacy of explorative treatment necessitated conversion to open intervention in 6 (13.1% 0 patients. The use of extracorporeal lithotripsy as a monotherapy in coral nephrolithiasis is now limited.

  10. Histomorphologic and ultrastructural findings of shockwave-induced lesions in the isolated perfused kidney of the pig.

    PubMed

    Back, W; Köhrmann, K U; Bensemann, J; Rassweiler, J; Alken, P

    1994-08-01

    The aim of this investigation was the development of an easily reproducible model with which to evaluate shockwave-induced renal tissue damage using light and electron microscopy. Kidneys (n = 45) from freshly slaughtered pigs were perfused under physiologic conditions and treated with shockwaves at different doses (2-250 shockwaves; 12-20 kV) on the Modulith SL 20 lithotripter. The dose-dependent alterations in tissue structure were characterized by disintegration of tubular cells leading to circumscribed gap-like defects resulting from reticular fiber disruptions. Even after low shockwave doses, cellular and subcellular alterations could be observed. Our findings in this ex vivo model verify the development of considerable strictly localized, dose-dependent shockwave-induced damage of the renal parenchyma. On morphologic grounds, we cannot confirm a primary lesion or rupture of blood vessel walls as the cause of the shockwave lesions. The destruction of tubular cells in combination with disruption of peritubular and pericapillary reticular fiber coats results in capillarotubular leaks, which can explain even severe transitory macrohematuria after clinical shockwave lithotripsy without renal hematoma formation.

  11. Dense Hypervelocity Plasma Jets

    NASA Astrophysics Data System (ADS)

    Case, Andrew; Witherspoon, F. Douglas; Messer, Sarah; Bomgardner, Richard; Phillips, Michael; van Doren, David; Elton, Raymond; Uzun-Kaymak, Ilker

    2007-11-01

    We are developing high velocity dense plasma jets for fusion and HEDP applications. Traditional coaxial plasma accelerators suffer from the blow-by instability which limits the mass accelerated to high velocity. In the current design blow-by is delayed by a combination of electrode shaping and use of a tailored plasma armature created by injection of a high density plasma at a few eV generated by arrays of capillary discharges or sparkgaps. Experimental data will be presented for a complete 32 injector gun system built for driving rotation in the Maryland MCX experiment, including data on penetration of the plasma jet through a magnetic field. We present spectroscopic measurements of plasma velocity, temperature, and density, as well as total momentum measured using a ballistic pendulum. Measurements are in agreement with each other and with time of flight data from photodiodes and a multichannel PMT. Plasma density is above 10^15 cm-3, velocities range up to about 100 km/s. Preliminary results from a quadrature heterodyne HeNe interferometer are consistent with these results.

  12. Extracorporeal shockwave therapy promotes chondrogenesis in cartilage tissue engineering: A hypothesis based on previous evidence.

    PubMed

    Ji, Qiaodan; He, Chengqi

    2016-06-01

    The dearth of intrinsic regenerative capacity of articular cartilage makes it a challenge to deal with the cartilage defects. Among all the recommended clinical options, cartilage tissue engineering (CTE) which is highlighted of dominant features and less drawbacks for functional cartilage restoration, has been emphasized recently. Shock waves, a mode of therapeutic mechanical forces, utilized in extracorporeal shockwave therapy (ESWT), is hypothesized to enhance proliferation, chondrogenic differentiation, and cartilage extracellular matrix production of target cells seeded on bioactive scaffolds. The hypothesis is firstly based on cellular mechanotransduction by which cells convent the shockwave mechanical signals into biochemical responses via integrins, iron channels, cytoskeletal filaments, growth factor receptors and nuclei. Secondly, by modulating gene expression and up-regulating the release of various growth factors which are of vital importance in three-dimensional cartilage culture environment, ESWT holds a promising potential to favor the cell sources (e.g. chondrocytes and stem cells) to mimic the optimal functional cartilage. In all, on the basis of cellular mechanotransduction and previous evidence, the hypothesis is developed to support the beneficial effects of ESWT on chondrogenesis in CTE. If this hypothesis is confirmed, shockwaves may allow a better success in combination with other stimulating factors for cartilage repair. There is a paucity of studies investigating the assistant role of shockwave stimulation in CTE. Further research is required to elucidate the mechanisms, and explore effectiveness and appropriate protocols of this novel stimulative factor in cartilage tissue engineering.

  13. Endoscopic gallbladder catheterisation and extracorporeal shockwave lithotripsy in the management of Mirizzi's syndrome.

    PubMed

    Martin, D F; Tweedle, D E; Rao, P N

    1988-11-01

    A novel approach to the management of Mirizzi's syndrome due to a mucocele of the gallbladder is reported. Endoscopic retrograde catheterisation of the gallbladder permitted decompression, and was followed by extracorporeal shockwave lithotripsy of gallbladder calculi in an 80-year-old man considered unfit for operation.

  14. Effects of extracorporeal shockwave lithotripsy on renal growth and function: an animal model.

    PubMed

    Claro, J de A; Denardi, F; Ferreira, U; Rodrigues Netto, N; Saldanha, L B; Figueiredo, J F

    1994-06-01

    The long-term effects of extracorporeal shockwave lithotripsy (SWL) on children are unclear. At 40 days of age, with an average weight of 166 g, 34 Wistar white rats were divided into three groups: 9 rats (control group) received no shockwaves, 10 rats (Group 1) received 1000 shockwaves at 16.0 kV, and 15 animals (Group 2) received 1000 shockwaves at 17.2 kV. Six months later, at maturity, body weight; lithium and creatinine; fractional sodium, potassium, and lithium excretion; and the clearances of lithium and creatinine were measured, and the kidneys were studied grossly and histologically. We found no significant changes in overall animal or renal growth between the post-SWL groups and the control group. However, there were significant changes in renal function, mainly in Group 2; the animals of this group presented a significant increase in blood lithium and potassium, besides a significant decrease in the fractional potassium excretion compared with the control group. Furthermore, the animals in Group 2 showed permanent histologic renal changes, including red cells in Bowman's capsule and glomerular congestion. The disorders caused by SWL are compatible with hyporeninemic hypoaldosteronism, an inappropriate low plasma renin activity and aldosterone deficiency. We conclude that SWL does not affect either overall animal or renal growth but may cause permanent histologic damage and significant changes in renal function.

  15. [The application of extracorporeal shock-wave lithotripsy in the treatment of choledocholithiasis].

    PubMed

    Nichitaĭlo, M E; Ogorodnik, P V; Goĭda, S M; Diachenko, V V; Goĭda, M S; Sobchinskiĭ, S A; Voĭtseshin, V V; Gul'ko, O N

    2001-10-01

    The method of extracorporal shockwave biliary lithotripsy was introduced in the clinic since 1993 yr in patients with residual choledocholithiasis. The method was applied in 25 patients. Cholecystectomy with external drainage of common biliary duct was performed in all patients beforehand. Positive result was noted in 16 observations. All patients are alive.

  16. Hypercalciuria and renal stones in a sarcoidosis patient treated by extracorporeal shockwave lithotripsy.

    PubMed

    Sharma, O P; Alfaro, C

    1986-03-01

    A case of chronic pulmonary sarcoidosis and hypercalciuria complicated by bilateral renal stones is reported. Urinary stones were pulverized by extracorporeal shockwave lithotripsy (ESWL) as the patient had declined any surgical procedure. The use of ESWL in conjunction with corticosteroids appears to be the treatment of choice in the management of renal stones secondary to abnormalities of calcium metabolism in sarcoidosis.

  17. Effectiveness of extracorporeal shockwave treatment in 353 patients with chronic plantar fasciitis.

    PubMed

    Norris, Donald M; Eickmeier, Kimberly M; Werber, Bruce R

    2005-01-01

    A 16-question post-treatment survey was sent to 874 patients after extracorporeal shockwave treatment for chronic plantar fasciitis. Of the 377 surveys returned, 353 were used for analysis. These patients were treated by 169 physicians in 19 states using either electrohydraulic or electromagnetic extracorporeal shockwave equipment. Seventy-six percent of the patients underwent treatment after having had continued pain for a year or longer. Seventy percent of patients who rated their pretreatment pain level as severe (score >or= 8 on a scale from 1 to 10) experienced sharp declines in pain, with a sharp decline considered to be a difference in pain level before and after treatment of 3 or more. In addition, 66% of patients who rated their pretreatment immobility as severe (score >or= 8 on a scale from 1 to 10) experienced sharp declines in immobility. Of the patients who underwent extracorporeal shockwave treatment, 69% indicated that they would recommend this procedure to someone in a similar situation. If extracorporeal shockwave treatment were not available, 62% of patients indicated that they would have undergone open or invasive surgery, and 41% indicated that they would have continued with additional physician office visits.

  18. Extracorporeal shockwave therapy promotes chondrogenesis in cartilage tissue engineering: A hypothesis based on previous evidence.

    PubMed

    Ji, Qiaodan; He, Chengqi

    2016-06-01

    The dearth of intrinsic regenerative capacity of articular cartilage makes it a challenge to deal with the cartilage defects. Among all the recommended clinical options, cartilage tissue engineering (CTE) which is highlighted of dominant features and less drawbacks for functional cartilage restoration, has been emphasized recently. Shock waves, a mode of therapeutic mechanical forces, utilized in extracorporeal shockwave therapy (ESWT), is hypothesized to enhance proliferation, chondrogenic differentiation, and cartilage extracellular matrix production of target cells seeded on bioactive scaffolds. The hypothesis is firstly based on cellular mechanotransduction by which cells convent the shockwave mechanical signals into biochemical responses via integrins, iron channels, cytoskeletal filaments, growth factor receptors and nuclei. Secondly, by modulating gene expression and up-regulating the release of various growth factors which are of vital importance in three-dimensional cartilage culture environment, ESWT holds a promising potential to favor the cell sources (e.g. chondrocytes and stem cells) to mimic the optimal functional cartilage. In all, on the basis of cellular mechanotransduction and previous evidence, the hypothesis is developed to support the beneficial effects of ESWT on chondrogenesis in CTE. If this hypothesis is confirmed, shockwaves may allow a better success in combination with other stimulating factors for cartilage repair. There is a paucity of studies investigating the assistant role of shockwave stimulation in CTE. Further research is required to elucidate the mechanisms, and explore effectiveness and appropriate protocols of this novel stimulative factor in cartilage tissue engineering. PMID:27142133

  19. Ultrafast Time Response Pressure-Sensitive Paint for Unsteady Shock-Wave Research

    NASA Astrophysics Data System (ADS)

    Numata, Daiju; Asai, Keisuke

    Pressure-Sensitive Paint (PSP) is an optical pressure measurement technique widely used in aerodynamic experiments, and has been applied to unsteady shock-wave phenomena [1, 2]. However, one of the largest problems to apply PSP to high-speed and unsteady phenomena is the response time of PSP.

  20. One-year treatment follow-up of plantar fasciitis: radial shockwaves vs. conventional physiotherapy

    PubMed Central

    Grecco, Marcus Vinicius; Brech, Guilherme Carlos; Greve, Júlia Maria D'Andrea

    2013-01-01

    OBJECTIVE: To compare radial shockwave treatment with conventional physiotherapy for plantar fasciitis after 12 months of follow-up. METHOD: This was a randomized, prospective, comparative clinical study. Forty patients with a diagnosis of plantar fasciitis were divided randomly into two treatment groups: group 1, with 20 patients who underwent ten physiotherapy sessions comprising ultrasound, kinesiotherapy and guidance for home-based stretching; and group 2, with 20 patients who underwent three applications of radial shockwaves, once a week, and guidance for home-based stretching. All patients were assessed regarding pain and functional abilities before treatment, immediately after and 12 months after treatment. The mean age was 49.6±11.8 years (range: 25-68 years), 85% were female, 88% were overweight, 63% were affected bilaterally, and 83% used analgesics regularly. RESULTS: At the 12-month follow-up, both treatments were effective for improving pain and functional ability among the patients with plantar fasciitis. The improvement with shockwaves was faster. CONCLUSION: Shockwave treatment was not more effective than conventional physiotherapy treatment 12 months after the end of the treatment. PMID:24037003

  1. Analysis of flexible substrates for clinical translation of laser-generated shockwave therapy

    PubMed Central

    Francis, Nathan C.; Kassam, Imara; Nowroozi, Bryan; Grundfest, Warren S.; Taylor, Zach D.

    2015-01-01

    Bacteria biofilms in chronically infected wounds significantly increase the burden of healthcare costs and resources for patients and clinics. Because biofilms are such an effective barrier to standard antibiotic treatment, new methods of therapy need to be developed to combat these infections. Our group has demonstrated the potential of using Laser Generated Shockwaves as a potential therapy to mechanically disrupt the bacterial biofilms covering the wound. Previous studies have used rigid silica glass as the shockwave propagation medium, which is not compatible with the intended clinical application. This paper describes the exploration of five candidate flexible plastic films to replace the glass substrate. Each material measured 0.254 mm thick and was used to generate shockwaves of varying intensities. Shockwave characterization was performed using a high-speed Michelson displacement interferometer and peak stress values obtained in the flexible substrates were compared to glass using one-way nested Analysis of Variance and Tukey HSD post-hoc analysis. Results demonstrate statistically significant differences between substrate material and indicate that polycarbonate achieves the highest peak stress for a given laser fluence suggesting that it is optimal for clinical applications. PMID:25798307

  2. Analysis of flexible substrates for clinical translation of laser-generated shockwave therapy.

    PubMed

    Francis, Nathan C; Kassam, Imara; Nowroozi, Bryan; Grundfest, Warren S; Taylor, Zach D

    2015-03-01

    Bacteria biofilms in chronically infected wounds significantly increase the burden of healthcare costs and resources for patients and clinics. Because biofilms are such an effective barrier to standard antibiotic treatment, new methods of therapy need to be developed to combat these infections. Our group has demonstrated the potential of using Laser Generated Shockwaves as a potential therapy to mechanically disrupt the bacterial biofilms covering the wound. Previous studies have used rigid silica glass as the shockwave propagation medium, which is not compatible with the intended clinical application. This paper describes the exploration of five candidate flexible plastic films to replace the glass substrate. Each material measured 0.254 mm thick and was used to generate shockwaves of varying intensities. Shockwave characterization was performed using a high-speed Michelson displacement interferometer and peak stress values obtained in the flexible substrates were compared to glass using one-way nested Analysis of Variance and Tukey HSD post-hoc analysis. Results demonstrate statistically significant differences between substrate material and indicate that polycarbonate achieves the highest peak stress for a given laser fluence suggesting that it is optimal for clinical applications.

  3. A solid-phase mechanism of shock-wave formation of dust particles of heavy metals

    NASA Astrophysics Data System (ADS)

    Lin, E. E.; Mikhailov, A. L.; Khvorostin, V. N.

    2016-08-01

    The possibility of formation of dust particles in solid as a result of shock-wave destruction of the initial crystalline material structure and subsequent coalescence of atomic clusters (nanoparticles), which leads to the aggregation of mesocrystalline particles (grains) in the shocked layer, is discussed.

  4. The development and performance of a message-passing version of the PAGOSA shock-wave physics code

    SciTech Connect

    Gardner, D.R.; Vaughan, C.T.

    1997-10-01

    A message-passing version of the PAGOSA shock-wave physics code has been developed at Sandia National Laboratories for multiple-instruction, multiple-data stream (MIMD) computers. PAGOSA is an explicit, Eulerian code for modeling the three-dimensional, high-speed hydrodynamic flow of fluids and the dynamic deformation of solids under high rates of strain. It was originally developed at Los Alamos National Laboratory for the single-instruction, multiple-data (SIMD) Connection Machine parallel computers. The performance of Sandia`s message-passing version of PAGOSA has been measured on two MIMD machines, the nCUBE 2 and the Intel Paragon XP/S. No special efforts were made to optimize the code for either machine. The measured scaled speedup (computational time for a single computational node divided by the computational time per node for fixed computational load) and grind time (computational time per cell per time step) show that the MIMD PAGOSA code scales linearly with the number of computational nodes used on a variety of problems, including the simulation of shaped-charge jets perforating an oil well casing. Scaled parallel efficiencies for MIMD PAGOSA are greater than 0.70 when the available memory per node is filled (or nearly filled) on hundreds to a thousand or more computational nodes on these two machines, indicating that the code scales very well. Thus good parallel performance can be achieved for complex and realistic applications when they are first implemented on MIMD parallel computers.

  5. [Extracorporeal shockwave lithotripsy of stones in lower calices of kidney].

    PubMed

    Martov, A G; Peniukova, I V; Moskalenko, S A; Peniukov, V G; Peniukov, D V; Balykov, I S

    2013-01-01

    The article presents the results of the study aimed to evaluation of possible relationship between anatomical structure of the renal pelvis of the kidney, the size of the stone and the effectiveness of extracorporeal shockwave lithotripsy (ESWL) of stones in lower calices of kidney, defined as "stone-free state". ESWL was performed in 285 patients. Sizes of stones varied from 5 to 25 mm. With interval distribution of stone sizes, the greatest number of cases was detected with size of 5 to 12 mm. The destruction of stone required one ESWL session in 196 cases, and three sessions only in 12 cases. The total number of pulses per one stone did not exceed 9500, and more than 70% of the stones have been effectively destroyed with less than 3000 pulses. The result of treatment was assessed 3-4 months after the last ESWL session on the basis of ultrasound and X-ray examination using nominal (dichotomous) scale. In addition, for verification of significant (expected and unexpected) correlations, exploratory analysis of the correlation matrices of factors possibly affecting the discharge of stone fragments was performed. Positive treatment outcome was recorded in 212 (74.4%) patients. Residual stone fragments (> or = 5 mm) were identified in 73 (25.6%) patients; in 69 patients fragments corresponded to the initial localization and 4 fragments were located in the pelvis and calices of middle and lower segments of the kidney. Statistical processing found no association between the size of the stone and the number of ESWL sessions required for its destruction (P = 0,4056). The analysis of relationship between the nature of the complications and size of stone revealed differences, but there were no significant differences in median test (p = 0.1067). Based on exploratory analysis and correlations identified, in-depth evaluation was carried out on three factors: the size of the stone, length of lower calices neck, and pyelocaliceal corner. Width of lower calices neck as a

  6. Advancement of Shock-wave Induced Spraying Process through the Study of Gas and Particle Flow Fields

    NASA Astrophysics Data System (ADS)

    Karimi Esfahani, Mohammad

    This research advances the knowledge of the working principles of the Shock-wave Induced Spraying Process (SISP), a thermal spray material deposition technique. Pulses created by a fast acting valve pass through a heated line increasing energy content and interacting with metered batches of heated or non-heated powder introduced into the line. The powder is accelerated to high velocities before bonding to the substrate upon impact. Advantages over other cold spray processes include cost savings and a more effective transfer of thermal energy to the powder. The shock-wave occurring near the substrate in other cold spray processes is avoided. The SISP flow field is resolved by using a computational model. The two-dimensional model accounts for the valve, gas heater, a tapered nozzle at the tip of the device, and preheating of the powder. It is implemented with a commercial computational fluid dynamics code. Comparisons are made with one-dimensional predictions, and measurements of pressure and temperature. Particle flow predictions are validated using particle velocity and adhesion measurements. A flow region of both high temperature and velocity gas, favorable to material deposition, forms which is not present in comparable steady-state cold spray processes. Increasing gas pressure increases the gas speed, while increasing temperature increases speed and temperature of this region. Using helium results in greater energy levels but for shorter periods of time. This indicates the need for a powder feeder which places particles in the flow at correct instants and durations of time. The effects of particle flow parameters on system performance are examined. It is found that the device must be operated at very high main heater and powder heater temperatures: 900 °C and 700 °C respectively to achieve a coating with stainless steel using nitrogen as the driving gas. It is also shown that a heater length range of 0.9 m to 1.4 m results in the greatest likelihood of

  7. A passive acoustic device for real-time monitoring of the efficacy of shockwave lithotripsy treatment.

    PubMed

    Leighton, T G; Fedele, F; Coleman, A J; McCarthy, C; Ryves, S; Hurrell, A M; De Stefano, A; White, P R

    2008-10-01

    Extracorporeal shockwave lithotripsy (ESWL) is the preferred modality for the treatment of renal and ureteric stone disease. Currently X-ray or ultrasound B-scan imaging are used to locate the stone and to check that it remains targeted at the focus of the lithotripter during treatment. Neither imaging modality is particularly effective in allowing the efficacy of treatment to be judged during the treatment session. A new device is described that, when placed on the patient's skin, can passively monitor the acoustic signals that propagate through the body after each lithotripter shock, and which can provide useful information on the effectiveness of targeting. These acoustic time histories are analyzed in real time to extract the two main characteristic peak amplitudes (m(1) and m(2)) and the time between these peaks (t(c)). A set of rules based on the acoustic parameters was developed during a clinical study in which a complete set of acoustic and clinical data was obtained for 30 of the 118 subjects recruited. The rules, which complied with earlier computational fluid dynamics (CFD) modeling and in vitro tests, allow each shock to be classified as "effective" or "ineffective." These clinically-derived rules were then applied in a second clinical study in which complete datasets were obtained for 49 of the 85 subjects recruited. This second clinical study demonstrated almost perfect agreement (kappa = 0.94) between the number of successful treatments, defined as >50% fragmentation as determined by X-ray at the follow-up appointment, and a device-derived global treatment score, TS(0), a figure derived from the total number of effective shocks in any treatment. The acoustic system is shown to provide a test of the success of the treatment that has a sensitivity of 91.7% and a specificity of 100%. In addition to the predictive capability, the device provides valuable real-time feedback to the lithotripter operator by indicating the effectiveness of each shock, plus

  8. Effects of extracorporeal shockwave therapy on nanostructural and biomechanical responses in the collagenase-induced Achilles tendinitis animal model.

    PubMed

    Yoo, Seung Don; Choi, Samjin; Lee, Gi-Ja; Chon, Jinmann; Jeong, Yong Seol; Park, Hun-Kuk; Kim, Hee-Sang

    2012-11-01

    The aim of this study was to quantitatively investigate the effects of extracorporeal shockwave therapy (ESWT) on the nanostructure and adhesion force of collagen fibrils in a rat model of collagenase-induced Achilles tendinitis (CIAT) using histology and atomic force microscopy. A total of 45 rats were divided into experimental groups of three rats each: a control group, 27 CIAT rats with nine time points, and 15 ESWT rats with five time points. Progressive changes in nanostructure including the fibrillary diameter and D-periodicity, and biomechanical properties including the fibrillary adhesion forces in each healing phase were investigated over a 5-week period after collagenase injection. On postoperative day 3, CIAT rats showed granulomatous tissue associated with subacute inflammation, and a deterioration in nanostructure and mechanical properties compared to controls. On postoperative day 12, the ESWT group showed increased vascularity, fibroblastic activity, lymphocyte and plasma cell infiltration, dense histocytes, and disorganization of the fibers compared to the CIAT group. The ESWT group showed and improvement in nanostructure and mechanical properties compared to controls, while the CIAT group showed a deterioration in nanostructure and mechanical properties compared to controls. On postoperative day 26, the ESWT group showed 30% inflamed tissue and 70% fibrotic tissue, while the CIAT group showed chronic inflammation. By the end of the experiments, in both groups the changes had reversed and the tissues were similar in appearance to those in the control group. Following ESWT the deformed and irregular collagen network returned to a well-aligned normal collagen network nanostructure. These results suggest that ESWT may promote the healing response in Achilles tendinitis.

  9. Application systems for intracorporeal laser-induced shockwave lithotripsy using the Nd:YAG Q-switched laser.

    PubMed

    Frank, F; Eichenlaub, M; Hessel, S; Wondrazek, F

    1990-10-01

    For laser-induced shockwave lithotripsy, the electromagnetic energy of a laser light pulse is converted intracorporeally into the acoustic energy of a shockwave. The lithotriptor is based on a specially developed, Q-switched Nd:YAG laser whose high power light pulses (70 mJ, 25 nsec) are coupled into a flexible quartz fiber with a core diameter of 600 mum. Using focusing elements, energy densities higher than 6 x 10 5 J m -2 can be achieved, resulting in an optical breakdown in water followed by a shockwave. As a result of different absorption mechanisms, the breakdown threshold can be decreased by placing a metallic target into the laser beam. The different shockwave formations of such optomechanical transducers have been measured. First clinical applications have been performed.

  10. Theory and Simulation of Warm Dense Matter Targets

    SciTech Connect

    Barnard, J J; Armijo, J; More, R M; Friedman, A; Kaganovich, I; Logan, B G; Marinak, M M; Penn, G E; Sefkow, A B; Santhanam, P; Wurtele, J S

    2006-07-13

    We present simulations and analysis of the heating of warm dense matter foils by ion beams with ion energy less than one MeV per nucleon to target temperatures of order one eV. Simulations were carried out using the multi-physics radiation hydrodynamics code HYDRA and comparisons are made with analysis and the code DPC. We simulate possible targets for a proposed experiment at LBNL (the so-called Neutralized Drift Compression Experiment, NDCXII) for studies of warm dense matter. We compare the dynamics of ideally heated targets, under several assumed equation of states, exploring dynamics in the two-phase (fluid-vapor) regime.

  11. Constitutive relations for steady, dense granular flows

    NASA Astrophysics Data System (ADS)

    Vescovi, D.; Berzi, D.; di Prisco, C. G.

    2011-12-01

    In the recent past, the flow of dense granular materials has been the subject of many scientific works; this is due to the large number of natural phenomena involving solid particles flowing at high concentration (e.g., debris flows and landslides). In contrast with the flow of dilute granular media, where the energy is essentially dissipated in binary collisions, the flow of dense granular materials is characterized by multiple, long-lasting and frictional contacts among the particles. The work focuses on the mechanical response of dry granular materials under steady, simple shear conditions. In particular, the goal is to obtain a complete rheology able to describe the material behavior within the entire range of concentrations for which the flow can be considered dense. The total stress is assumed to be the linear sum of a frictional and a kinetic component. The frictional and the kinetic contribution are modeled in the context of the critical state theory [8, 10] and the kinetic theory of dense granular gases [1, 3, 7], respectively. In the critical state theory, the granular material approaches a certain attractor state, independent on the initial arrangement, characterized by the capability of developing unlimited shear strains without any change in the concentration. Given that a disordered granular packing exists only for a range of concentration between the random loose and close packing [11], a form for the concentration dependence of the frictional normal stress that makes the latter vanish at the random loose packing is defined. In the kinetic theory, the particles are assumed to interact through instantaneous, binary and uncorrelated collisions. A new state variable of the problem is introduced, the granular temperature, which accounts for the velocity fluctuations. The model has been extended to account for the decrease in the energy dissipation due to the existence of correlated motion among the particles [5, 6] and to deal with non

  12. Solids flow rate measurement in dense slurries

    SciTech Connect

    Porges, K.G.; Doss, E.D.

    1993-09-01

    Accurate and rapid flow rate measurement of solids in dense slurries remains an unsolved technical problem, with important industrial applications in chemical processing plants and long-distance solids conveyance. In a hostile two-phase medium, such a measurement calls for two independent parameter determinations, both by non-intrusive means. Typically, dense slurries tend to flow in laminar, non-Newtonian mode, eliminating most conventional means that usually rely on calibration (which becomes more difficult and costly for high pressure and temperature media). These issues are reviewed, and specific solutions are recommended in this report. Detailed calculations that lead to improved measuring device designs are presented for both bulk density and average velocity measurements. Cross-correlation, chosen here for the latter task, has long been too inaccurate for practical applications. The cause and the cure of this deficiency are discussed using theory-supported modeling. Fluid Mechanics are used to develop the velocity profiles of laminar non-Newtonian flow in a rectangular duct. This geometry uniquely allows the design of highly accurate `capacitive` devices and also lends itself to gamma transmission densitometry on an absolute basis. An absolute readout, though of less accuracy, is also available from a capacitive densitometer and a pair of capacitive sensors yields signals suitable for cross-correlation velocity measurement.

  13. Quantum molecular dynamics simulations of dense matter

    SciTech Connect

    Collins, L.; Kress, J.; Troullier, N.; Lenosky, T.; Kwon, I.

    1997-12-31

    The authors have developed a quantum molecular dynamics (QMD) simulation method for investigating the properties of dense matter in a variety of environments. The technique treats a periodically-replicated reference cell containing N atoms in which the nuclei move according to the classical equations-of-motion. The interatomic forces are generated from the quantum mechanical interactions of the (between?) electrons and nuclei. To generate these forces, the authors employ several methods of varying sophistication from the tight-binding (TB) to elaborate density functional (DF) schemes. In the latter case, lengthy simulations on the order of 200 atoms are routinely performed, while for the TB, which requires no self-consistency, upwards to 1000 atoms are systematically treated. The QMD method has been applied to a variety cases: (1) fluid/plasma Hydrogen from liquid density to 20 times volume-compressed for temperatures of a thousand to a million degrees Kelvin; (2) isotopic hydrogenic mixtures, (3) liquid metals (Li, Na, K); (4) impurities such as Argon in dense hydrogen plasmas; and (5) metal/insulator transitions in rare gas systems (Ar,Kr) under high compressions. The advent of parallel versions of the methods, especially for fast eigensolvers, presage LDA simulations in the range of 500--1000 atoms and TB runs for tens of thousands of particles. This leap should allow treatment of shock chemistry as well as large-scale mixtures of species in highly transient environments.

  14. Anaesthesia for extracorporeal shockwave lithotripsy at the Victorian Lithotripsy Service--the first 300 patients.

    PubMed

    Silbert, B S; Kluger, R; Dixon, G C; Berg, J

    1988-08-01

    A prospective survey was undertaken of the anaesthesia for the first 300 patients at the Victorian Lithotripsy Service. The majority (71.7%) were not hospitalised on site, including four quadriplegics and two ASA grade IV patients. Two hundred and eighty-three (94.3%) patients received continuous lumbar epidural anaesthesia, sixteen (5.3%) received general anaesthesia and one received a spinal anaesthetic. Eighty-two patients (27.3%) underwent ancillary procedures at the time of extracorporeal shockwave lithotripsy. The most common intraoperative complications were hypotension (72 patients, 25.4%) and shivering (39 patients, 13.8%). Arrhythmias occurred in nine (3%) patients. There was a 90% patient follow-up rate and the most common postoperative complication was backache (101 patients, 37.4%). The problems of anaesthesia for extracorporeal shockwave lithotripsy are discussed. Epidural anaesthesia offers a number of advantages for this procedure and proved very suitable for the majority of patients.

  15. [Ultrasound controlled extracorporeal shockwave lithotripsy of pancreatic calculi in patients with chronic recurrent pancreatitis].

    PubMed

    Schreiber, F; Gurakuqi, G C; Trauner, M; Krejs, G J

    1994-09-01

    A consecutive series of 10 patients with pancreatic stones due to chronic pancreatitis was treated by extracorporeal shockwave lithotripsy during an investigation period of 2 years. The first step of the therapeutic regime included an endoscopic sphincterotomy prior to shockwave treatment. The targeting procedure was performed strictly under sonographic control. All patients were treated with a second-generation electrohydraulic lithotriptor, fragmentation could be achieved in all 10 cases. In 7 patients stonefreeness could be reached by endoscopic stone extraction, all these patients were symptom-free over a follow-up period of 12 months. In 3 patients complete duct clearance could not be achieved, these patients presented with minor symptoms over the follow-up period.

  16. New developments in shockwave technology intended for meat tenderization: Opportunities and challenges. A review.

    PubMed

    Bolumar, Tomas; Enneking, Mathias; Toepfl, Stefan; Heinz, Volker

    2013-12-01

    Meat tenderness is an important quality parameter determining consumer acceptance and price. Meat tenderness is difficult to ensure in the global meat chain because the production systems are not always aiming at this purpose (ex.: cattle derived from milk production) and by the existence within the carcass of "tough" primals. Different methods can be used by the meat industry to improve meat tenderness each with its advantages and drawbacks. The application of hydrodynamic pressure or shockwaves has showed outstanding improvements by reducing the Warner Bratzler Shear Force by 25% or more. However, the technology has not penetrated into the market as first systems were based on the use of explosives and further developments seemed to lack the robustness to fulfill industrial requirements. The present paper describes the main challenges to construct a prototype for the continuous treatment of meat by shockwaves based on electrical discharges under water. Finally, improvements on the tenderness of meat by using the novel prototype are presented.

  17. Enhancement of laser plasma extreme ultraviolet emission by shockwave-laser interaction

    SciTech Connect

    Bruijn, Rene de; Koshelev, Konstantin N.; Zakharov, Serguei V.; Novikov, Vladimir G.; Bijkerk, Fred

    2005-04-15

    A double laser pulse heating scheme has been applied to generate plasmas with enhanced emission in the extreme ultraviolet (EUV). The plasmas were produced by focusing two laser beams (prepulse and main pulse) with a small spatial separation between the foci on a xenon gas jet target. Prepulses with ps-duration were applied to obtain high shockwave densities, following indications of earlier published results obtained using ns prepulses. EUV intensities around 13.5 nm and in the range 5-20 nm were recorded, and a maximum increase in intensity exceeding 2 was measured at an optimal delay of 140 ns between prepulse and main pulse. The gain in intensity is explained by the interaction of the shockwave produced by the prepulse with the xenon in the beam waist of the main pulse. Extensive simulation was done using the radiative magnetohydrodynamic code Z{sup *}.

  18. Shock-wave therapy is effective for chronic calcifying tendinitis of the shoulder.

    PubMed

    Loew, M; Daecke, W; Kusnierczak, D; Rahmanzadeh, M; Ewerbeck, V

    1999-09-01

    We report a prospective study of the effects of extracorporeal shock-wave therapy in 195 patients with chronic calcifying tendinitis. In part A 80 patients with chronic symptoms were randomly assigned to a control and three subgroups which had different treatment by low-energy and high-energy shock waves. In part B 115 patients had either one or two high-energy sessions. We recorded subjective, functional and radiological findings at six months after treatment. The results showed energy-dependent success, with relief of pain ranging from 5% in our control group up to 58% after two high-energy sessions. The Constant scores and the radiological disintegration of calcification were also dose-dependent. Shockwave therapy should be considered for chronic pain due to calcific tendinitis which is resistant to conservative treatment.

  19. A review of the cellular and molecular effects of extracorporeal shockwave therapy.

    PubMed

    Chamberlain, Georgina A; Colborne, G Robert

    2016-01-01

    Extracorporeal shockwave therapy (ESWT) is a novel therapeutic modality and its use in promoting connective tissue repair and analgesic effect has been advocated in the literature. It is convenient, cost-effective, and has negligible complications; it therefore bypasses many of the problems associated with surgical interventions. This paper reviews the proposed mechanisms of action in promoting tissue repair and regeneration as well as analysing its efficacy providing an analgesic effect in clinical applications. Further research will be required to not only identify the underlying mechanisms more precisely, but will also be critical for ensuring consistency across the literature so that the most beneficial treatment protocol can be developed. Extracorporeal shockwave therapy stands as a promising alternative modality in promoting tissue repair.

  20. Tenderization of chicken and turkey breasts with electrically produced hydrodynamic shockwaves.

    PubMed

    Claus, J R; Schilling, J K; Marriott, N G; Duncan, S E; Solomon, M B; Wang, H

    2001-07-01

    Eighty early deboned (45 min, post mortem) postrigor chicken breasts were exposed (24 h post mortem) to two levels (number of pulse firing networks, PFN; 45% energy) of electrically produced hydrodynamic shockwaves (HSW). In addition, 21 turkey breasts (72 h post mortem) were HSW treated (two PFN, 72% energy). Samples were water cooked in bags (78°C internal). Two PFN's were required to decrease (P<0.05) chicken Warner-Bratzler shear (WBS) force by 22% from the control (4.67 kg). WBS force of the HSW treated turkey breast decreased (P<0.05) by 12% from the control (3.20 kg). Cooking loss was higher (P<0.05) in the turkey breast portions but not in the chicken breasts. The electrically produced shockwave process has the potential to provide chicken processors with the ability to early debone and produce tender breasts and to provide turkey processors with tenderness-enhanced fillets.

  1. [Gallbladder morphology after extracorporeal shockwave lithotripsy of gallstones with the MPL-9000].

    PubMed

    Frick, T; Cerncic, P; Hoffmann, R; Stamm, B; Largiadèr, F

    1991-07-01

    The effects of extracorporeal spark-gap shockwave lithotripsy (ESWL) on human gallbladder-morphology are barely known. We studied the gallbladders of nine patients cholecystectomized 5 to 166 days after ESWL. Patients were treated one to three times receiving a mean of 1928 +/- 693 shockwaves per treatment, with a total of 3375 +/- 1307 per patient. Control gallbladders were of randomly selected patients after plain cholecystectomy (age and sex-matched). There was no difference in pathomorphology of the two groups. No signs of trauma related damage (hemorrhage, necrosis, ulceration, scar, or hemosiderin deposits) other than from surgical manipulation were found. Predominant pathomorphological changes were signs of chronic cholecystitis due to gallstone disease. In conclusion, spark-gap ESWL did not induce deleterious morphological damage to the gallbladder, although large numbers of shock waves were applied.

  2. [Endoscopic lithotripsy with pneumatic shockwave (Swiss Lithoclast) using a mini-ureteroscope].

    PubMed

    Knispel, H H; Klän, R; Dieckmann, K P

    1993-09-01

    We performed endoscopic lithotripsy for 23 urinary stones (21 ureteral and 2 bladder stones) with a pneumatic shockwave unit (Swiss Lithoclast; EMS, Angiomed), for the first time applying the probe through the tangential working channel of a semirigid 6.9-Fr ureteroscope (Circon, ACMI). Disintegration was successful in all stones (5-24 mm). Immediately after treatment, the 2 patients with bladder calculi and 10 of the patients with ureteral stones (47.6%) were stone free, while another 5 had residual fragments < 3 mm. Migration of fragments in 4 patients (19%) led to subsequent extracorporeal shock wave lithotripsy. There were no ureteral perforations in this series. Routine application of double-J stents avoided any serious postoperative complications. Endoscopic lithotripsy with the pneumatic shockwave unit was shown to be highly effective regardless of stone composition. The ltihotripsy probe is easily applied through mini-ureteroscopes.

  3. [Percutaneous removal of kidney calculi and extracorporeal shockwave lithotripsy in patients with hemorrhagic diatheses].

    PubMed

    Kirschner, P; Ziemer, S; Brien, G; Gromnica-Ihle, E; Schöpke, W; Sydow, K

    1988-07-01

    Hemorrhage is the main complication of percutaneous kidney stone removal. Shock-wave lithotripsy also may causes bleeding complications. It seems that both procedures are contraindicated on patients with coagulation disorders. On the base of two cases the specification of treatment by patients with hemorrhagic diatheses is demonstrated. Modern treatment modalities of urinary stone disease are also applicable to those patients, when attention is paid to some conditions and attentive measures are taken.

  4. Small bowel perforation after extracorporeal shockwave lithotripsy of an ureter stone.

    PubMed

    Klug, R; Kurz, F; Dunzinger, M; Aufschnaiter, M

    2001-01-01

    A 60-year-old man was treated by extracorporeal shock wave lithotripsy (ESWL) for an impacted ureter stone. Two days after the procedure he developed an acute abdomen. On laparotomy, a small bowel perforation in the area of an adhesion to the abdominal wall was found. The adherent intestinal segment was located exactly in the range of the ESWL field, so that excluding further reasons the shockwave lithotripsy must be assumed to be causative.

  5. Extracorporeal shockwave lithotripsy for a giant calcified gallbladder stone. Case report.

    PubMed

    Herbetko, J; Burhenne, H J

    1992-03-01

    Extracorporeal shockwave lithotripsy to gallstones is an alternative treatment to surgery in the high-risk patient with acute cholecystitis. We describe the successful fragmentation of a giant gallbladder stone and the subsequent removal of fragments through a cholecystostomy tract. Even though the treatment required 22 days in hospital and multiple procedures, these were all considered low risk in this patient with severe chronic obstructive airway disease.

  6. Modification of Dornier HM-4 lithotriptor for pediatric extracorporeal shockwave lithotripsy.

    PubMed

    Mathews, R; Makhuli, Z; Rahrle, R; Patil, U

    1995-06-01

    Extracorporeal shockwave lithotripsy has enjoyed increasing acceptance and utility in pediatric urology. The Dornier HM-4 lithotriptor has had good results in adults, but the gantry design does not allow smaller children to be treated. We have employed a specially designed yet simple 'spacer' to allow smaller children to be treated safely. The device may also have application in other patients with deformities who could not be treated in the past.

  7. Experience with electrohydraulic shockwave lithotripsy in the treatment of vesical calculi.

    PubMed

    Zhaowu, Z; Xiwen, W; Fenling, Z

    1988-06-01

    Five hundred and two patients with bladder stones have been treated by electrohydraulic shockwave lithotripsy (EHSWL) with the Wolf RIWOLTH-2135 disintegrator. The patients were aged between 18 and 80 years. The largest stone measured 3.6 x 4.8 cm but most were less than 3 cm; 533 stones were disintegrated in the 502 patients. The indications and complications of the treatment are discussed.

  8. Extracorporeal piezoelectric shockwave lithotripsy of multiple pancreatic duct stones under ultrasonographic control.

    PubMed

    Kerzel, W; Ell, C; Schneider, T; Matek, W; Heyder, N; Hahn, E G

    1989-09-01

    The first ultrasonographically controlled fragmentation of multiple pancreatic duct stones of up to 14 mm size by means of extracorporeal, piezoelectric shockwave lithotripsy is reported. On account of the ultrasound localization and continuous control during therapy a nasopancreatic tube for instillation of contrast medium and frequent x-ray checks were not necessary. The 48-year-old patient did not experience any pain during the four treatment sessions and during the follow-up period. No complications were noted.

  9. Gene expression for extracellular matrix proteins in shockwave-induced osteogenesis in rats.

    PubMed

    Takahashi, Kenji; Yamazaki, Masashi; Saisu, Takashi; Nakajima, Arata; Shimizu, Sumito; Mitsuhashi, Shigeru; Moriya, Hideshige

    2004-02-01

    To clarify the mechanisms underlying shockwave-induced osteogenesis, we applied shockwave to rat femoral shafts from the ventral side. We assessed bone mineral content (BMC) and bone mineral density (BMD), and analyzed the spatial and temporal gene expression for pro-alpha1 (I) collagen (COL1A1), pro-alpha1 (II) collagen (COL2A1), pro-alpha1 (X) collagen (COL10A1), osteocalcin (OC) and osteopontin (OPN) using in situ hybridization. On the 21st day post-exposure, BMC and BMD in the exposed femur were elevated by 8.46% and 5.80%, respectively, relative to the unexposed femur. Immediately following exposure, there was evidence of scraping of the cortex and periosteal separation with hemorrhage. On day 4, new periosteal bone formation could be seen on the ventral and dorsal side of the femur. In the newly formed bone, COL1A1, OC and OPN were expressed in osteoblastic cells underlying the periosteum. On day 7, there was progression of periosteal bone and trabeculae formation. COL1A1 and OC were expressed in mature osteoblasts lining the trabeculae, whereas OPN was expressed in immature osteoblastic cells, osteocytes and osteoclasts. On day 14, bone remodeling commenced in the periosteal bone. COL1A1, OC and OPN were still expressed at this stage, however, signals were much weaker. Between 4-7 days, chondrocyte clusters were distributed multi-focally near the exposed site, and there was expression of COL2A1 but not of COL10A1. The results demonstrate that gene expression patterns of shockwave-induced osteogenesis are similar to those of periosteal hard callus formation during fracture healing. Shockwaves can yield dramatic activation of cells in normal long bones, and drive the cells to express genes for osteogenesis.

  10. [The effect of extracorporeal shockwave lithotripsy on the indices of urinary enzymes in nephrolithiasis patients].

    PubMed

    Neĭmark, A I; Fidirkin, A V; Zhukov, V N

    1997-01-01

    Immediate and long-term effects of extracorporeal shock-wave lithotripsy (ESWL) on urine enzymes were studied in 200 patients with nephrolithiasis (NL). The patients had abnormally high urine excretion of AP, GGT, APA, LDH and NAG, whereas aminotransferases excretion was low. Pathobiochemical and diagnostic implications of these findings are discussed. Immediately after its conduction ESWL entails a mild injury to tubular portion of the nephron. The causes of long-term stay of enzymuria after ESWL in NL patients are discussed.

  11. High-energy v low-energy shockwave lithotripsy in treatment of ureteral calculi.

    PubMed

    Mathes, G L; Mathes, L T

    1997-10-01

    The size of the crater formed in a urinary calculus subjected to shockwave lithotripsy (SWL) is directly proportional to the energy delivered to the stone surface. This study compared the effect of high and low energy levels on the outcomes of ureteral SWL. Ureteral calculi (N = 336) were treated with the conventional low-energy Siemens Lithostar and 62 with the higher-energy (1.02 v 0.5 mJ/mm2) modification of the Lithostar, the Siemens Shock Tube C. Stone locations included all regions of the ureter. The average stone treated with the standard Lithostar measured 8.1 mm in diameter and received 5461 shockwaves (treatment time 45 minutes) at 17.2 kV (range 14.5-19.0 kV). The stone-free rate was 72%, with stents being used in 16% of patients and a retreatment rate of 9%. The typical stone treated with Shock Tube C was 10.4 mm in diameter and received 3528 shockwaves (treatment time 30 minutes) at an average energy setting of 4.1 (range 1.5-8.0). The stone-free rate was 75%, with stents being used in 9.8% of cases, and a retreatment rate of only 1.6% (P < 0.003). In this study, Shock Tube C yielded stone-free rates equivalent to those of the conventional machine. However, the number of shockwaves, treatment time, and retreatment rate were significantly lower with the new shock tube. High-energy lithotripsy is more efficient than low-energy treatment of ureteral calculi.

  12. Current knowledge on evidence-based shockwave treatments for shoulder pathology.

    PubMed

    Moya, Daniel; Ramón, Silvia; Guiloff, Leonardo; Gerdesmeyer, Ludger

    2015-12-01

    Shoulder pain is one of the most common musculoskeletal pathologies. Treatment by ESWT (extracorporeal shockwave therapy) has emerged as an alternative when conservative treatment fails in rotator cuff calcific tendinopathy, prior to invasive procedures. The clinical efficacy of ESWT in non-calcific tendinopathy remains controversial. The good results in the treatment of rotator cuff calcifications, have led to indications of ESWT being expanded to other shoulder pathologies. We review the current state of indications and evidence based practice.

  13. Shock-Wave and Plasma-Pinch Mechanisms of Galactic Cosmic-Ray Production

    SciTech Connect

    Trubnikov, B.A.

    2005-07-01

    Based on recent discoveries, we show that it is appropriate to complement the standard shock-wave model for the production of galactic cosmic rays by a plasma-pinch model. The latter describes well the production of high-energy cosmic rays, yields a simple formula for their intensity, and allows the threshold pattern of the knee-type kink in the secondary particle spectrum and a number of unusual phenomena observed above the threshold to be explained.

  14. Acute and chronic bioeffects of single and multiple doses of piezoelectric shockwaves (EDAP LT.01).

    PubMed

    Ryan, P C; Jones, B J; Kay, E W; Nowlan, P; Kiely, E A; Gaffney, E F; Butler, M R

    1991-02-01

    Piezoelectric second generation lithotriptors are an established means of administering extracorporeal shockwave lithotripsy (ESWL) enabling treatment to be performed without anaesthesia or analgesia, but higher shockwave doses and multiple or staged treatment are frequently required. The bioeffects of this modality of ESWL, therefore, require further assessment. Seven experimental groups of adult male rabbits were treated using the EDAP LT.01 in order to determine the acute and chronic bioeffects of clinical dose, excess dose, divided excess dose, high frequency and multiple treatment (X10) piezoelectric shockwaves (PSW). Renal function was measured before and after treatment using mercaptoacetyltriglycine (MAG 3) scans. Gross and histological morphological changes were assessed at one and 30 days following application of PSW. Application of single clinical dose PSW was not associated with any significant functional or morphological renal injury. Excess dose PSW caused transient gross renal contusion, which resolved in the majority of animals with no persistent microscopic abnormality. Divided excess dose PSW resulted in no gross or microscopic damage. High frequency PSW was associated with mild histological abnormality. Multiple PSW treatments caused small discrete fibrotic lesions in all cases, without any change in renal function.

  15. Effects of extracorporeal shockwave lithotripsy at different stages of pregnancy in the rabbit.

    PubMed

    Gümüş, B; Lekili, M; Kandiloğlu, A R; Işisağ, A; Temeltaş, G; Nazli, O; Büyüksu, C

    1997-10-01

    Although SWL is now the most common treatment modality for urinary tract stone disease, it is not regarded as a safe method for pregnant patients because of its potential harmful effects on fetus. Using a rabbit model, we investigated whether SWL might cause fetal injury when administered at various developmental stages. Two groups of pregnant rabbits were given 1000 shockwaves either early or late in the gestational period. Time-matched controls did not receive shockwaves. After spontaneous labor, all newborn rabbits were counted, weighted, and measured, and specimens were taken from organs and examined histopathologically. The numbers, weights, and diameters of the newborns in each group were similar. There was no notable histopathologic finding in the heart and brain specimens of any of the newborns, whereas noticeable congestion and multiple focal intraparanchymal microhemorrhages were found in lungs, livers, and kidneys of the animals that had been exposed to shockwaves early in gestation. In conclusion, this study shows that SWL is not a safe treatment in early pregnancy.

  16. Functional and histologic alterations in growing solitary rat kidney as result of extracorporeal shockwaves.

    PubMed

    Ferreira, U; Claro, J de A; Rodrigues Netto, N; Denardi, F; Figueiredo, J F; Riccetto, C L

    1995-02-01

    The long-term effects of extracorporeal shockwave lithotripsy (SWL) on children treated for renal calculi are unclear. To study the effects on the immature animal, we evaluated 31 Wistar white rats that underwent right nephrectomy at 30 days of age. At 40 days of age they were divided into three groups: a control group of 10 rats that received no shockwaves; Group I (9 rats) that received 1000 shockwaves at 16.0 kV, and Group II (12 animals) that received 1000 shock waves at 17.2 kV. Six months later at maturity (7 months and 10 days of age), the following parameters were measured: (1) body and renal weight; (2) blood lithium, sodium, potassium, and creatinine; (3) fractional lithium, sodium, and potassium excretion; and (4) clearances of lithium and creatinine. The kidneys were studied grossly and histologically. We found no significant changes in overall animal and renal growth between the post-SWL and control groups. However, there were significant changes in renal function. The animals in Groups I and II presented significant increases in blood potassium compared with the control group. Furthermore, the 1000 x 17.2 kV group showed permanent histologic renal changes, including red cells in Bowman's capsule and glomerular congestion. The disorders caused by SWL are compatible with hyporeninemic hypoaldosteronism, inappropriately low plasma renin activity, and aldosterone deficiency.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. Molecular and cellular effects of in vitro shockwave treatment on lymphatic endothelial cells.

    PubMed

    Rohringer, Sabrina; Holnthoner, Wolfgang; Hackl, Matthias; Weihs, Anna M; Rünzler, Dominik; Skalicky, Susanna; Karbiener, Michael; Scheideler, Marcel; Pröll, Johannes; Gabriel, Christian; Schweighofer, Bernhard; Gröger, Marion; Spittler, Andreas; Grillari, Johannes; Redl, Heinz

    2014-01-01

    Extracorporeal shockwave treatment was shown to improve orthopaedic diseases and wound healing and to stimulate lymphangiogenesis in vivo. The aim of this study was to investigate in vitro shockwave treatment (IVSWT) effects on lymphatic endothelial cell (LEC) behavior and lymphangiogenesis. We analyzed migration, proliferation, vascular tube forming capability and marker expression changes of LECs after IVSWT compared with HUVECs. Finally, transcriptome- and miRNA analyses were conducted to gain deeper insight into the IVSWT-induced molecular mechanisms in LECs. The results indicate that IVSWT-mediated proliferation changes of LECs are highly energy flux density-dependent and LEC 2D as well as 3D migration was enhanced through IVSWT. IVSWT suppressed HUVEC 3D migration but enhanced vasculogenesis. Furthermore, we identified podoplaninhigh and podoplaninlow cell subpopulations, whose ratios changed upon IVSWT treatment. Transcriptome- and miRNA analyses on these populations showed differences in genes specific for signaling and vascular tissue. Our findings help to understand the cellular and molecular mechanisms underlying shockwave-induced lymphangiogenesis in vivo.

  18. International shock-wave database project : report of the requirements workshop.

    SciTech Connect

    Aidun, John Bahram; Lomonosov, Igor V.; Levashov, Pavel R.

    2012-03-01

    We report on the requirements workshop for a new project, the International Shock-Wave database (ISWdb), which was held October 31 - November 2, 2011, at GSI, Darmstadt, Germany. Participants considered the idea of this database, its structure, technical requirements, content, and principles of operation. This report presents the consensus conclusions from the workshop, key discussion points, and the goals and plan for near-term and intermediate-term development of the ISWdb. The main points of consensus from the workshop were: (1) This international database is of interest and of practical use for the shock-wave and high pressure physics communities; (2) Intermediate state information and off-Hugoniot information is important and should be included in ISWdb; (3) Other relevant high pressure and auxiliary data should be included to the database, in the future; (4) Information on the ISWdb needs to be communicated, broadly, to the research community; and (5) Operating structure will consist of an Advisory Board, subject-matter expert Moderators to vet submitted data, and the database Project Team. This brief report is intended to inform the shock-wave research community and interested funding agencies about the project, as its success, ultimately, depends on both of these groups finding sufficient value in the database to use it, contribute to it, and support it.

  19. Characterization of acoustic shockwaves generated by exposure to nanosecond electrical pulses

    NASA Astrophysics Data System (ADS)

    Roth, Caleb C.; Maswadi, Saher; Ibey, Bennett L.; Beier, Hope T.; Glickman, Randolph D.

    2014-03-01

    Despite 30 years of research, the mechanism behind the induced breakdown of plasma membranes by electrical pulses, termed electroporation, remains unknown. Current theories treat the interaction between the electrical field and the membrane as an entirely electrical event pointing to multiple plausible mechanisms. By investigating the biophysical interaction between plasma membranes and nanosecond electrical pulses (nsEP), we may have identified a non-electric field driven mechanism, previously unstudied in nsEP, which could be responsible for nanoporation of plasma membranes. In this investigation, we use a non-contact optical technique, termed probe beam deflection technique (PBDT), to characterize acoustic shockwaves generated by nsEP traveling through tungsten wire electrodes. We conclude these acoustic shockwaves are the result of the nsEP exposure imparting electrohydraulic forces on the buffer solution. When these acoustic shockwaves occur in close proximity to lipid bilayer membranes, it is possible that they impart a sufficient amount of mechanical stress to cause poration of that membrane. This research establishes for the first time that nsEP discharged in an aqueous medium generate measureable pressure waves of a magnitude capable of mechanical deformation and possibly damage to plasma membranes. These findings provide a new insight into the longunanswered question of how electric fields cause the breakdown of plasma membranes.

  20. Dense gas shock tube: Design and analysis

    NASA Astrophysics Data System (ADS)

    Fergason, Stephen Harrison

    The study of BZT fluids in the single-phase vapor region is largely unexamined experimentally. To date, only one experimental study focused on nonclassical behavior in the single-phase vapor region. A new experimental program is proposed to examine the possibility of generating nonclassical behaviors in a shock tube apparatus. A design methodology is developed to identify the most important experimental characteristics and provide appropriate analytical and computational tools for subsequent study. Analysis suggests initial conditions, viscous effects, and wave interference as critical experimental characteristics. A shock tube design is proposed based on the results of the methodology. An algorithm is developed and applied to classical state equations to generate experimentally feasible initial conditions which maximize the possibility of detecting a single-phase rarefaction shock wave within experimental accuracy and precision. The algorithm was applied to a commercially available fluid thought to exhibit dense gas behavior. It was found that the range of possible initial conditions generating dense gas phenomena is larger than previously assumed. The shock tube is computationally modeled to validate the triple-discontinuity initial conditions and investigate the appropriate design dimensions. A two-step, flux-limited, total variation diminishing scheme was implemented to integrate the unsteady Navier-Stokes equations using three independent gas models. The triple-discontinuity flow field was verified with simulations. A novel shock tube was constructed based on the previous analysis. A sixteen-foot stainless steel pipe with a single diaphragm was placed within a series of electric ovens. The test section thermal environment was controlled utilizing sixteen independent PID control loops. Initial conditions similar in pressure and temperature to dense gas conditions were generated for nitrogen gas. The nitrogen test results were compared with classical one

  1. Shockwaves induce osteogenic differentiation of human mesenchymal stem cells through ATP release and activation of P2X7 receptors.

    PubMed

    Sun, Dahui; Junger, Wolfgang G; Yuan, Changji; Zhang, Wenyan; Bao, Yi; Qin, Daming; Wang, Chengxue; Tan, Lei; Qi, Baochang; Zhu, Dong; Zhang, Xizheng; Yu, Tiecheng

    2013-06-01

    Shockwave treatment promotes bone healing of nonunion fractures. In this study, we investigated whether this effect could be due to adenosine 5'-triphosphate (ATP) release-induced differentiation of human mesenchymal stem cells (hMSCs) into osteoprogenitor cells. Cultured bone marrow-derived hMSCs were subjected to shockwave treatment and ATP release was assessed. Osteogenic differentiation and mineralization of hMSCs were evaluated by examining alkaline phosphatase activity, osteocalcin production, and calcium nodule formation. Expression of P2X7 receptors and c-fos and c-jun mRNA was determined with real-time reverse transcription polymerase chain reaction and Western blotting. P2X7-siRNA, apyrase, P2 receptor antagonists, and p38 MAPK inhibitors were used to evaluate the roles of ATP release, P2X7 receptors, and p38 MAPK signaling in shockwave-induced osteogenic hMSCs differentiation. Shockwave treatment released significant amounts (≈ 7 μM) of ATP from hMSCs. Shockwaves and exogenous ATP induced c-fos and c-jun mRNA transcription, p38 MAPK activation, and hMSC differentiation. Removal of ATP with apyrase, targeting of P2X7 receptors with P2X7-siRNA or selective antagonists, or blockade of p38 MAPK with SB203580 prevented osteogenic differentiation of hMSCs. Our findings indicate that shockwaves release cellular ATP that activates P2X7 receptors and downstream signaling events that caused osteogenic differentiation of hMSCs. We conclude that shockwave therapy promotes bone healing through P2X7 receptor signaling, which contributes to hMSC differentiation.

  2. Shockwaves Induce Osteogenic Differentiation of Human Mesenchymal Stem Cells Through ATP Release and Activation of P2X7 Receptors

    PubMed Central

    Sun, Dahui; Junger, Wolfgang G.; Yuan, Changji; Zhang, Wenyan; Bao, Yi; Qin, Daming; Wang, Chengxue; Tan, Lei; Qi, Baochang; Zhu, Dong; Zhang, Xizheng; Yu, Tiecheng

    2014-01-01

    Shockwave fractures treatment promotes bone healing of nonunion fractures. In this study, we investigated whether this effect could be due to adenosine 5’-triphosphate (ATP) release-induced differentiation of human mesenchymal stem cells (hMSCs) into osteoprogenitor cells. Cultured bone marrow-derived hMSCs were subjected to shockwave treatment and ATP release was assessed. Osteogenic differentiation and mineralization of hMSCs were evaluated by examining alkaline phosphatase activity, osteocalcin production, and calcium nodule formation. Expression of P2X7 receptors and c-fos and c-jun mRNA was determined with real-time reverse transcription polymerase chain reaction and Western blotting. P2X7-siRNA, apyrase, P2 receptor antagonists, and p38 MAPK inhibitors were used to evaluate the roles of ATP release, P2X7 receptors, and p38 MAPK sig naling in shockwave-induced osteogenic hMSCs differentiation. Shockwave treatment released significant amounts (~7 μM) of ATP from hMSCs. Shockwaves and exogenous ATP induced c-fos and c-jun mRNA transcription, p38 MAPK activation, and hMSC differentiation. Removal of ATP with apyrase, targeting of P2X7 receptors with P2X7-siRNA or selective antagonists, or blockade of p38 MAPK with SB203580 prevented osteogenic differentiation of hMSCs. Our findings indicate that shockwaves release cellular ATP that activates P2X7 receptors and downstream signaling events that caused osteogenic differentiation of hMSCs. We conclude that shockwave therapy promotes bone healing through P2X7 receptor signaling, which contributes to hMSC differentiation. PMID:23404811

  3. Chemical potential calculations in dense liquids using metadynamics

    NASA Astrophysics Data System (ADS)

    Perego, C.; Giberti, F.; Parrinello, M.

    2016-07-01

    The calculation of chemical potential has traditionally been a challenge in atomistic simulations. One of the most used approaches is Widom's insertion method in which the chemical potential is calculated by periodically attempting to insert an extra particle in the system. In dense systems this method fails since the insertion probability is very low. In this paper we show that in a homogeneous fluid the insertion probability can be increased using metadynamics. We test our method on a supercooled high density binary Lennard-Jones fluid. We find that we can obtain efficiently converged results even when Widom's method fails.

  4. Experimental basis of shockwave-induced renal trauma in the model of the canine kidney.

    PubMed

    Rassweiler, J; Köhrmann, K U; Back, W; Fröhner, S; Raab, M; Weber, A; Kahmann, F; Marlinghaus, E; Jünemann, K P; Alken, P

    1993-01-01

    Using the new electromagnetic shockwave source of the Modulith SL 20 shockwave-induced renal trauma was evaluated by acute and chronic studies in the the canine kidney model. In a further study the electromagnetic shockwave source of the Lithostar Plus Overhead module was tested. Overall, 92 kidneys were exposed to shock waves coupled either by water bath (Modulith lab type) or by water cushion (Modulith prototype, Lithostar Overhead) under ultrasound localization. The generator voltage ranged between 11 and 21 kV, the number of impulses between 25 and 2500. After application of 1500/2500 shocks the extent of the renal lesion depended strictly on the applied generator voltage and was classified into 4 grades: Grade 0, no macroscopic trauma detectable (at 11-12 kV); grade 1, petechial medullary bleeding (at 13 kV); grade 2, cortical hematoma (at 14-16 kV); and grade 3, perirenal hematoma (17-20 kV). Whereas at low and medium energy levels the number of shocks played only a minor role, at maximal generator voltage (20 kV) even 25 impulses induced a grade 2 and 600 shocks a grade 3 lesion, emphasizing the importance of shockwave limitation in the upper energy range. In shockwave-induced renal trauma a vascular lesion was predominant and cellular necrosis was secondary. Coupling with a water cushion resulted in a 15%-20% decrease in the disintegrative and traumatic effect, which was compensated for by increasing the generator voltage by 2 kV. Long-term studies showed complete restitution following grade 1 and 2 trauma, whereas after a grade 3 lesion a small segmental and capsular fibrosis without hyperplasia of the juxtaglomerular apparatus was observed. Based on the characteristic ultrasound pattern found in the first study, the threshold for induction of grade 1 lesion was investigated. With both lithotripters a wide range for induction of a grade 1 lesion (Modulith 234-411, Lithostar Plus 220-740) and also a significant overlapping with grade 0 and 2 lesions was

  5. Experimental basis of shockwave-induced renal trauma in the model of the canine kidney.

    PubMed

    Rassweiler, J; Köhrmann, K U; Back, W; Fröhner, S; Raab, M; Weber, A; Kahmann, F; Marlinghaus, E; Jünemann, K P; Alken, P

    1993-01-01

    Using the new electromagnetic shockwave source of the Modulith SL 20 shockwave-induced renal trauma was evaluated by acute and chronic studies in the the canine kidney model. In a further study the electromagnetic shockwave source of the Lithostar Plus Overhead module was tested. Overall, 92 kidneys were exposed to shock waves coupled either by water bath (Modulith lab type) or by water cushion (Modulith prototype, Lithostar Overhead) under ultrasound localization. The generator voltage ranged between 11 and 21 kV, the number of impulses between 25 and 2500. After application of 1500/2500 shocks the extent of the renal lesion depended strictly on the applied generator voltage and was classified into 4 grades: Grade 0, no macroscopic trauma detectable (at 11-12 kV); grade 1, petechial medullary bleeding (at 13 kV); grade 2, cortical hematoma (at 14-16 kV); and grade 3, perirenal hematoma (17-20 kV). Whereas at low and medium energy levels the number of shocks played only a minor role, at maximal generator voltage (20 kV) even 25 impulses induced a grade 2 and 600 shocks a grade 3 lesion, emphasizing the importance of shockwave limitation in the upper energy range. In shockwave-induced renal trauma a vascular lesion was predominant and cellular necrosis was secondary. Coupling with a water cushion resulted in a 15%-20% decrease in the disintegrative and traumatic effect, which was compensated for by increasing the generator voltage by 2 kV. Long-term studies showed complete restitution following grade 1 and 2 trauma, whereas after a grade 3 lesion a small segmental and capsular fibrosis without hyperplasia of the juxtaglomerular apparatus was observed. Based on the characteristic ultrasound pattern found in the first study, the threshold for induction of grade 1 lesion was investigated. With both lithotripters a wide range for induction of a grade 1 lesion (Modulith 234-411, Lithostar Plus 220-740) and also a significant overlapping with grade 0 and 2 lesions was

  6. Enhanced Productivity of Chemical Processes Using Dense Fluidized Beds

    SciTech Connect

    Sibashis Banerjee; Alvin Chen; Rutton Patel; Dale Snider; Ken Williams; Timothy O'Hern; Paul Tortora

    2008-02-29

    The work detailed in this report addresses Enabling Technologies within Computational Technology by integrating a “breakthrough” particle-fluid computational technology into traditional Process Science and Engineering Technology. The work completed under this DOE project addresses five major development areas 1) gas chemistry in dense fluidized beds 2) thermal cracking of liquid film on solids producing gas products 3) liquid injection in a fluidized bed with particle-to-particle liquid film transport 4) solid-gas chemistry and 5) first level validation of models. Because of the nature of the research using tightly coupled solids and fluid phases with a Lagrangian description of the solids and continuum description of fluid, the work provides ground-breaking advances in reactor prediction capability. This capability has been tested against experimental data where available. The commercial product arising out of this work is called Barracuda and is suitable for a wide (dense-to-dilute) range of industrial scale gas-solid flows with and without reactions. Commercial applications include dense gas-solid beds, gasifiers, riser reactors and cyclones.

  7. Dissipation of Molecular Cloud Turbulence by Magnetohydrodynamic Shockwaves

    NASA Astrophysics Data System (ADS)

    Lehmann, Andrew; Wardle, Mark

    2015-08-01

    The character of star formation is intimately related to the supersonic magnetohydrodynamic (MHD) turbulent dynamics of the giant molecular clouds in which stars form. A significant amount of the turbulent energy dissipates in low velocity shock waves. These shocks cause molecular line cooling of the compressed and heated gas, and so their radiative signatures probe the nature of the turbulence. In MHD fluids the three distinct families of shocks—fast, intermediate and slow—differ in how they compress and heat the molecular gas, and so observational differences between them may also distinguish driving modes of turbulent regions.Here we use a two-fluid model to compare the characteristics of one-dimensional fast and slow MHD shocks. Fast MHD shocks are magnetically driven, forcing ion species to stream through the neutral gas ahead of the shock front. This magnetic precursor heats the gas sufficiently to create a large, warm transition zone where all the fluid variables only weakly change in the shock front. In contrast, slow MHD shocks are driven by gas pressure where neutral species collide with ion species in a thin hot slab that closely resembles an ordinary gas dynamic shock.We computed observational diagnostics for fast and slow shocks at velocities vs = 2-4 km/s and preshock Hydrogen nuclei densities n(H) = 102-4 cm-3. We followed the abundances of molecules relevant for a simple oxygen chemistry and include cooling by CO, H2 and H2O. Estimates of intensities of CO rotational lines show that high-J lines, above J = 6→5, are more strongly excited in slow MHD shocks. We discuss how these shocks could help interpret recently observed anomalously strong mid- and high-J CO lines emitted by warm gas in the Milky Way and external galaxies, and implications for simulations of MHD turbulence.

  8. Liquidlike Behavior of Supercritical Fluids

    NASA Astrophysics Data System (ADS)

    Gorelli, F.; Santoro, M.; Scopigno, T.; Krisch, M.; Ruocco, G.

    2006-12-01

    The high frequency dynamics of fluid oxygen has been investigated by inelastic x-ray scattering, at high pressures and room temperature. In spite of the markedly supercritical conditions (T≈2Tc, P>102Pc), the sound velocity exceeds the hydrodynamic value of about 20%, a feature which is the fingerprint of liquidlike dynamics. The comparison of the present results with literature data obtained in several fluids allow us to identify the extrapolation of the liquid-vapor-coexistence line in the (P/Pc, T/Tc) plane as the relevant edge between liquidlike and gaslike dynamics. More interestingly, this extrapolation is very close to the non-metal-metal transition in hot dense fluids, at pressure and temperature values as obtained by shock wave experiments. This result points to the existence of a connection between structural modifications and transport properties in dense fluids.

  9. History of Ureteral Stenting Negatively Affects the Outcomes of Extracorporeal Shockwave Lithotripsy. Results of a Matched-pair Analysis.

    PubMed

    Sfoungaristos, Stavros; Gofrit, Ofer N; Pode, Dov; Landau, Ezekiel H; Yutkin, Vladimir; Latke, Arie; Duvdevani, Mordechai

    2015-01-01

    To evaluate the impact of ureteral stenting history to the outcomes of extracorporeal shockwave lithotripsy, we retrospectively analysed patients who underwent shockwave lithotripsy with Dornier Gemini lithotripter between September 2010 and August 2012. Forty seven patients (group A) who had a double J stent which was removed just before the procedure were matched-paired with another 47 patients (group B) who underwent shockwave lithotripsy having no stent history. The correlation between ureteral stenting history and stone-free rates was assessed. Stone-free rates were 68.1% and 87.2% for patients of group A and B, respectively (p=0.026). Postoperative complications were not different between groups. Multivariate analysis revealed that stone size (p=0.007), stone location (p=0.044) and history of ureteral stenting (p=0.046) were independent predictors for stone clearance after shockwave lithotripsy. Ureteral stents adversely affect shockwave lithotripsy outcome, even if they are removed before the procedure. Stenting history should divert treatment plan towards intracorporeal lithotripsy.

  10. History of Ureteral Stenting Negatively Affects the Outcomes of Extracorporeal Shockwave Lithotripsy. Results of a Matched-pair Analysis.

    PubMed

    Sfoungaristos, Stavros; Gofrit, Ofer N; Pode, Dov; Landau, Ezekiel H; Yutkin, Vladimir; Latke, Arie; Duvdevani, Mordechai

    2015-01-01

    To evaluate the impact of ureteral stenting history to the outcomes of extracorporeal shockwave lithotripsy, we retrospectively analysed patients who underwent shockwave lithotripsy with Dornier Gemini lithotripter between September 2010 and August 2012. Forty seven patients (group A) who had a double J stent which was removed just before the procedure were matched-paired with another 47 patients (group B) who underwent shockwave lithotripsy having no stent history. The correlation between ureteral stenting history and stone-free rates was assessed. Stone-free rates were 68.1% and 87.2% for patients of group A and B, respectively (p=0.026). Postoperative complications were not different between groups. Multivariate analysis revealed that stone size (p=0.007), stone location (p=0.044) and history of ureteral stenting (p=0.046) were independent predictors for stone clearance after shockwave lithotripsy. Ureteral stents adversely affect shockwave lithotripsy outcome, even if they are removed before the procedure. Stenting history should divert treatment plan towards intracorporeal lithotripsy. PMID:26445394

  11. Warm Dense Matter: An Overview

    SciTech Connect

    Kalantar, D H; Lee, R W; Molitoris, J D

    2004-04-21

    This document provides a summary of the ''LLNL Workshop on Extreme States of Materials: Warm Dense Matter to NIF'' which was held on 20, 21, and 22 February 2002 at the Wente Conference Center in Livermore, CA. The warm dense matter regime, the transitional phase space region between cold material and hot plasma, is presently poorly understood. The drive to understand the nature of matter in this regime is sparking scientific activity worldwide. In addition to pure scientific interest, finite temperature dense matter occurs in the regimes of interest to the SSMP (Stockpile Stewardship Materials Program). So that obtaining a better understanding of WDM is important to performing effective experiments at, e.g., NIF, a primary mission of LLNL. At this workshop we examined current experimental and theoretical work performed at, and in conjunction with, LLNL to focus future activities and define our role in this rapidly emerging research area. On the experimental front LLNL plays a leading role in three of the five relevant areas and has the opportunity to become a major player in the other two. Discussion at the workshop indicated that the path forward for the experimental efforts at LLNL were two fold: First, we are doing reasonable baseline work at SPLs, HE, and High Energy Lasers with more effort encouraged. Second, we need to plan effectively for the next evolution in large scale facilities, both laser (NIF) and Light/Beam sources (LCLS/TESLA and GSI) Theoretically, LLNL has major research advantages in areas as diverse as the thermochemical approach to warm dense matter equations of state to first principles molecular dynamics simulations. However, it was clear that there is much work to be done theoretically to understand warm dense matter. Further, there is a need for a close collaboration between the generation of verifiable experimental data that can provide benchmarks of both the experimental techniques and the theoretical capabilities. The conclusion of this

  12. Extracorporeal shockwaves induce the expression of ATF3 and GAP-43 in rat dorsal root ganglion neurons.

    PubMed

    Murata, Ryo; Ohtori, Seiji; Ochiai, Nobuyasu; Takahashi, Norimasa; Saisu, Takashi; Moriya, Hideshige; Takahashi, Kazuhisa; Wada, Yuichi

    2006-07-30

    Although extracorporeal shockwave has been applied in the treatment of various diseases, the biological basis for its analgesic effect remains unclear. Therefore, we investigated the dorsal root ganglion neurons of rats following shockwave exposure to the footpad to elucidate its effect on the peripheral nervous system. We used activating transcription factor 3 (ATF3) and growth-associated phosphoprotein (GAP-43) as markers for nerve injury and axonal regeneration, respectively. The average number of neurons immunoreactive for ATF3 increased significantly in the treated rats at all experimental time points, with 78.3% of those neurons also exhibiting immunoreactivity for GAP-43. Shockwave exposure induced injury of the sensory nerve fibers within the exposed area. This phenomenon may be linked to the desensitization of the exposure area, not the cause of pain, considering clinical research with a particular absence of painful adverse effect. Subsequent active axonal regeneration may account for the reinnervation of exposed area and the amelioration of the desensitization.

  13. Use of external shock-wave lithotripsy and adjuvant ursodiol for treatment of radiolucent gallstones. A national multicenter study.

    PubMed

    Burnett, D; Ertan, A; Jones, R; O'Leary, J P; Mackie, R; Robinson, J E; Salen, G; Stahlgren, L; Van Thiel, D H; Vassy, L

    1989-07-01

    A prospective multicenter trial was performed to evaluate the use of external shockwave lithotripsy (ESL) and adjuvant medical therapy for the treatment of gallstones. A Medstone STS lithotripter was used together with ursodiol. Two hundred twenty-three patients were treated under general anesthesia (75%) or with intravenous analgesia (25%). Initial treatments were on an inpatient basis, but as centers gained experience, outpatient treatments became more common. Stone fragmentation and clearance were greatest in patients with solitary gallstones less than 2 cm in diameter. In this group of patients, stone fragmentation occurred in 97% of patients, and the cumulative stone-free rates at three and six months were 54% and 90%, respectively. These results indicate that fragmentation of gallstones can be achieved by a dry shock-wave lithotripter and that stone clearance is induced more rapidly by external shock-wave lithotripsy and adjuvant ursodiol therapy than by ursodiol therapy alone.

  14. B1-b2 transition in calcium oxide from shock-wave and diamond-cell experiments.

    PubMed

    Jeanloz, R; Ahrens, T J; Mao, H K; Bell, P M

    1979-11-16

    Volume and structural data obtained by shock-wave and diamond-cell techniques demonstrate that calcium oxide transforms from the B1 (sodium chloride type) to the B2 (cesium chloride type) structure at 60 to 70 gigapascals (0.6 to 0.7 megabar) with a volume decrease of 11 percent. The agreement between the shockwave and diamond-cell results independently confirms the ruby-fluorescence pressure scale to about 65 gigapascals. The shock-wave data agree closely with ultrasonic measurements on the B1 phase and also agree satisfactorily with equations of state derived from ab initio calculations. The discovery of this B1-B2 transition is significant in that it allows considerable enrichment of calcium components in the earth's lower mantle, which is consistent with inhomogeneous accretion theories.

  15. Biophysical effects of pulsed lasers in the retina and other tissues containing strongly absorbing particles: shockwave and explosive bubble generation.

    PubMed

    Faraggi, Eshel; Gerstman, Bernard S; Sun, Jinming

    2005-01-01

    Damage by pulsed lasers to the retina or other tissues containing strongly absorbing particles may occur through biophysical mechanisms other than simple heating. Shockwaves and bubbles have been observed experimentally, and depending on pulse duration, may be the cause of retinal damage at threshold fluence levels. We perform detailed calculations on the shockwave and bubble generation expected from pulsed lasers. For a variety of different laser pulse durations and fluences, we tabulate the expected strength of the shockwave and size of the bubble that will be generated. We also explain how these results will change for absorbing particles with different physical properties such as absorption coefficient, bulk modulus, or thermal expansion coefficient. This enables the assessment of biological danger, and possible medical benefits, for lasers of a wide range of pulse durations and energies, incident on tissues with absorbing particles with a variety of thermomechanical characteristics.

  16. Dense, finely, grained composite materials

    DOEpatents

    Dunmead, Stephen D.; Holt, Joseph B.; Kingman, Donald D.; Munir, Zuhair A.

    1990-01-01

    Dense, finely grained composite materials comprising one or more ceramic phase or phase and one or more metallic and/or intermetallic phase or phases are produced by combustion synthesis. Spherical ceramic grains are homogeneously dispersed within the matrix. Methods are provided, which include the step of applying mechanical pressure during or immediately after ignition, by which the microstructures in the resulting composites can be controllably selected.

  17. Pacemakers, implantable cardioverter/defibrillators, and extracorporeal shockwave lithotripsy: evidence-based guidelines for the modern era.

    PubMed

    Platonov, Michael A; Gillis, Anne M; Kavanagh, Katherine M

    2008-02-01

    Early work examining interactions between extracorporeal shockwave lithotripsy (SWL) and implantable pacemakers or implantable cardioverter/defibrillators suggested that shockwave oversensing may result in inappropriate suppression of pacing, delivery of antitachycardia pacing therapy, delivery of inappropriate shock therapy, or outright damage to such devices. In the absence of national guidelines, those provided by manufacturers are nonuniform and practice patterns vary between centers. Improvements in SWL energy delivery as well as in device shielding and discrimination technologies have demonstrated improved safety data in recent years. We review these advances in both technologies as well as the most recent data to construct practice guidelines for the modern era.

  18. Acute cyst rupture, hemorrhage and septic shock after a shockwave lithotripsy in a patient with autosomal dominant polycystic kidney disease.

    PubMed

    Kim, Hyeong Gon; Bae, Sang Rak; Lho, Yong Soo; Park, Hyoung Keun; Paick, Sung Hyun

    2013-06-01

    The incidence of urinary calculi in autosomal dominant polycystic kidney disease (ADPKD) ranges from 10 to 36 %. Shockwave lithotripsy (SWL) for urinary calculi in ADPKD was reported to be a safe and effective treatment option. However, there is a potential risk of cyst rupture and traumatic hemorrhage because of shockwaves. A 39-year-old female with polycystic kidneys and upper ureter stone was treated with SWL and developed life-threatening complications of cyst rupture, traumatic hemorrhage and septic shock. She was initially treated with supportive care in the intensive care unit, but in the end nephrectomy was performed.

  19. Distinct metallization and atomization transitions in dense liquid hydrogen.

    PubMed

    Mazzola, Guglielmo; Sorella, Sandro

    2015-03-13

    We perform molecular dynamics simulations driven by accurate quantum Monte Carlo forces on dense liquid hydrogen. There is a recent report of a complete atomization transition between a mixed molecular-atomic liquid and a completely dissociated fluid in an almost unaccessible pressure range [Nat. Commun. 5, 3487 (2014)]. Here, instead, we identify a different transition between the fully molecular liquid and the mixed-atomic fluid at ∼400  GPa, i.e., in a much more interesting pressure range. We provide numerical evidence supporting the metallic behavior of this intermediate phase. Therefore, we predict that the metallization at finite temperature occurs in this partially dissociated molecular fluid, well before the complete atomization of the liquid. At high temperature this first-order transition becomes a crossover, in very good agreement with the experimental observation. Several systematic tests supporting the quality of our large scale calculations are also reported.

  20. Fluid fertilizers. [Fluids

    SciTech Connect

    Potts, J.M.

    1984-09-01

    The use of fertilizer in the United States has increased spectacularly in the past 20 years. In 1981 plant nutrient use (N + P/sub 2/O/sub 5/ + K/sub 2/O) totaled 23.5 million short tons - compared with only 7.5 million tons in 1960 (table 2). Nutrient use doubled from 1960 to 1970 and tripled from 1960 to 1981. In 1981 fluid nutrient use (mixtures plus nitrogen solutions) totaled 4.1 million tons, more than doubling since 1970 and increasing from 6.3% to 17.5% of the total nutrient use since 1960. Fluid mixtures (NPK) use in 1981 totaled 1.8 million tons of nutrients - about 17% of total mixed fertilizers or 7.5% of total nutrients used. The proportion of total fertilizer nutrients applied in fluid from increases greatly if anhydrous ammonia is included. The 4.6 million tons of nitrogen applied as anhydrous ammonia in 1981 increases total fluid nutrients to 8.1 million tons - 34.5% of the total nutrients applied in the United States. Fluid fertilizer use has grown nearly twice as fast as total fertilizer use, averaging more than 15% per year increase between 1960 and 1970, and an 11% increase between 1960 and 1980. A large part of this increase occurred during the introductory stages of the new product form and was aided by rapid advances in technology.

  1. Laser-induced shockwave paired with FRET: a method to study cell signaling.

    PubMed

    Gomez-Godinez, Veronica; Preece, Daryl; Shi, Linda; Khatibzadeh, Nima; Rosales, Derrick; Pan, Yijia; Lei, Lie; Wang, Yingxiao; Berns, Michael W

    2015-03-01

    Cells within the body are subject to various forces; however, the details concerning the way in which cells respond to mechanical stimuli are not well understood. We demonstrate that laser-induced shockwaves (LIS) combined with biosensors based on fluorescence resonance energy transfer (FRET) is a promising new approach to study biological processes in single live cells. As "proof-of-concept," using a FRET biosensor, we show that in response to LIS, cells release intracellular calcium. With the parameters used, cells retain their morphology and remain viable. LIS combined with FRET permits observation of the cells immediate response to a sudden shear force.

  2. Extracorporeal shockwave lithotripsy and percutaneous renal surgery. Comparisons, combinations and conclusions.

    PubMed

    Webb, D R; Payne, S R; Wickham, J E

    1986-02-01

    Although percutaneous nephrolithotomy (PCNL) and extracorporeal shockwave lithotripsy (ESWL) were introduced clinically at approximately the same time (1980-1981), their clinical progress appeared to progress along separate paths and to compete with each other. After 5 years it has become apparent that for optimal removal of nearly all renal stones by minimal or noninvasive techniques, PCNL and ESWL are required either separately or as combined procedures. This review traces the development, introduction and progress of these procedures and defines the current indications for extracorporeal, percutaneous and open renal stone surgery.

  3. [Extracorporeal shockwave lithotripsy: an alternative treatment for lithiasis of caliceal diverticula].

    PubMed

    García Reboll, L; Pontones, J; Boronat, F; Vera, C D; Broseta, E; Cuñat, E; Jiménez Cruz, J F

    1992-06-01

    Among all the patients treated in our Lithotrity Unit, 13 of them had lithiasis inside the calyceal diverticulum. They were all treated by extracorporeal shockwaves. In none of the cases complete expulsion of lithiasic mass was achieved. In 3 (23%) cases it was reduced to half. In 2 (15.3%), 75% of the initial mass remained; and in 8 (61.5%) stones were fragmented but none of their debris was eliminated. Out of all the patients who were symptomatic before starting treatment, only 36.6% become asymptomatic. Extracorporeal lithotrity is, therefore, an approach with limited results in the calyceal intradiverticular lithiasis.

  4. Post-extracorporeal shockwave lithotripsy residual stone fragments: clinical significance and management.

    PubMed

    Porfyris, O; Delakas, D

    2012-06-01

    Although extracorporeal shockwave lithotripsy (ESWL) is one of the primary treatments for urolithiasis, very often residual fragments of the calculi are still present for a long time after the ESWL session. These fragments are usually asymptomatic and can be managed expectantly, but sometimes they can cause symptoms and require intervention. Secondary procedures are not routinely applied to all patients with residual fragments, but only to those with significant symptoms. Medical therapy may play an important role in the management of residual fragments, by correcting an underlying metabolic disorder and by preventing the growth of residual calculi and the formation of new ones.

  5. [Experience of extracorporeal shock-wave lithotripsy for the urolithiasis in horseshoe kidney].

    PubMed

    Ohyama, A; Asai, Y; Ameno, Y; Sakakura, T; Sugita, O; Kamizuru, M; Sakamoto, W; Nakatani, T; Kishimoto, T; Maekawa, M

    1991-12-01

    At Osaka City University, 1,987 patients with urolithiasis have been treated by extra-corporeal shockwave lithotripsy (ESWL) during a four-year period. We treated 5 patients with horseshoe kidney and the obtained results were analyzed retrospectively. Three of these patients, who had a solitary stone could successfully be treated by ESWL as monotherapy. One who had multiple stones required transurethral lithotripsy after ESWL due to stone-street. The remaining 1 patient who had undergone heminephrectomy developed perirenal hematoma after ESWL, which spontaneously disappeared without any specific treatment. We discuss the special care related to the use of ESWL in the horseshoe kidney.

  6. Computation of sharp-fin-induced shockwave/turbulent boundary layer interactions

    NASA Technical Reports Server (NTRS)

    Horstman, C. C.

    1986-01-01

    Solutions of the Reynolds-averaged Navier-Stokes equations are presented and are compared with a family of experimental results for the three-dimensional interaction of a sharp-fin-induced shock wave with a turbulent boundary layer. The solutions predict most of the essential features of the flow fields for various shock-wave strengths. However, some features of the measured flow fields, such as secondary separation and size of the largest separated zones were not accurately computed. The computed flow fields, aided by particle tracing techniques, display a prominent vortical structure which can be correlated with the observed surface phenomena.

  7. Combination of percutaneous surgery and extracorporeal shockwave lithotripsy for the treatment of large renal calculi.

    PubMed

    Dickinson, I K; Fletcher, M S; Bailey, M J; Coptcoat, M J; McNicholas, T A; Kellett, M J; Whitfield, H N; Wickham, J E

    1986-12-01

    Open surgery for large or complex renal calculi may be difficult, particularly in patients with recurrent stones, and may require special operative techniques to preserve renal function. With the advent of percutaneous nephrolithotripsy (PCNL) and extracorporeal shockwave lithotripsy (ESWL) new approaches are now available for the treatment of these difficult cases. A review of 67 patients who presented between November 1984 and May 1986 has shown that it was possible to clear large stones in 71% of patients using a combination of PCNL and ESWL. There was no mortality; the morbidity for both procedures was low and was less than when either procedure was used alone for the treatment of complex stones.

  8. A case of portal venous gas after extracorporeal shockwave lithotripsy and obstructive pyelonephritis.

    PubMed

    Rana, Abbas A; Sylla, Patricia; Woodland, David C; Feingold, Daniel L

    2008-03-01

    The presence of gas in the portal venous system is considered an ominous sign often mandating immediate exploratory laparotomy; however, there are numerous reports of benign incidences of this finding. This report describes a case of portal venous gas after extracorporeal shockwave lithotripsy. The patient had the rare complication of obstructive pyleonephritis that progressed to sepsis and subsequently underwent a negative exploratory laparotomy. It is suggested that the radiographic finding of portal venous gas should be correlated with the likely cause and overall clinical picture.

  9. [Treatment of a subcapsular renal bleeding after extracorporeal shockwave lithotripsy with recombinant, activated factor VII].

    PubMed

    Langer, H; Strohmaier, W L; Probst, S

    2002-11-01

    We report on a patient who suffered a large subcapsular and perirenal haematoma after extracorporeal shockwave lithotripsy. Despite surgical intervention the bleeding did not stop for 6 days and 10 units of packed red blood cells were transfused. With the treatment of recombinant, activated factor VIII (NovoSeven((R))) an immediate haemostasis could be reached, so that impending nephrectomy could be avoided. This is the first case where FVIIa has been successfully used to stop a trauma-related bleeding in a patient without any obvious accompanying coagulation disorder.

  10. Arguments for choosing extracorporeal shockwave lithotripsy for removal of urinary tract stones.

    PubMed

    Tiselius, Hans-Göran; Chaussy, Christian G

    2015-10-01

    At a time when there is an almost unlimited enthusiasm and preference among urologists for endoscopic stone removal, we have found it essential to meet some of the frequently presented arguments on why extracorporeal shockwave lithotripsy (SWL) should not be used. We have based our considerations in this brief article on our 30-35 years' experience with the non-invasive or least invasive technique that SWL represents. Stone disintegration, requirement of repeated treatment sessions, the concern of residual fragments, complications and economic aspects are some points that are discussed.

  11. Laser-induced shockwave paired with FRET: a method to study cell signaling.

    PubMed

    Gomez-Godinez, Veronica; Preece, Daryl; Shi, Linda; Khatibzadeh, Nima; Rosales, Derrick; Pan, Yijia; Lei, Lie; Wang, Yingxiao; Berns, Michael W

    2015-03-01

    Cells within the body are subject to various forces; however, the details concerning the way in which cells respond to mechanical stimuli are not well understood. We demonstrate that laser-induced shockwaves (LIS) combined with biosensors based on fluorescence resonance energy transfer (FRET) is a promising new approach to study biological processes in single live cells. As "proof-of-concept," using a FRET biosensor, we show that in response to LIS, cells release intracellular calcium. With the parameters used, cells retain their morphology and remain viable. LIS combined with FRET permits observation of the cells immediate response to a sudden shear force. PMID:25639252

  12. Hugoniot measurements of double-shocked precompressed dense xenon plasmas.

    PubMed

    Zheng, J; Chen, Q F; Gu, Y J; Chen, Z Y

    2012-12-01

    The current partially ionized plasmas models for xenon show substantial differences since the description of pressure and thermal ionization region becomes a formidable task, prompting the need for an improved understanding of dense xenon plasmas behavior at above 100 GPa. We performed double-shock compression experiments on dense xenon to determine accurately the Hugoniot up to 172 GPa using a time-resolved optical radiation method. The planar strong shock wave was produced using a flyer plate impactor accelerated up to ∼6 km/s with a two-stage light-gas gun. The time-resolved optical radiation histories were acquired by using a multiwavelength channel optical transience radiance pyrometer. Shock velocity was measured and mass velocity was determined by the impedance-matching methods. The experimental equation of state of dense xenon plasmas are compared with the self-consistent fluid variational calculations of dense xenon in the region of partial ionization over a wide range of pressures and temperatures. PMID:23368058

  13. Constructing Dense Graphs with Unique Hamiltonian Cycles

    ERIC Educational Resources Information Center

    Lynch, Mark A. M.

    2012-01-01

    It is not difficult to construct dense graphs containing Hamiltonian cycles, but it is difficult to generate dense graphs that are guaranteed to contain a unique Hamiltonian cycle. This article presents an algorithm for generating arbitrarily large simple graphs containing "unique" Hamiltonian cycles. These graphs can be turned into dense graphs…

  14. Application of CHAD hydrodynamics to shock-wave problems

    SciTech Connect

    Trease, H.E.; O`Rourke, P.J.; Sahota, M.S.

    1997-12-31

    CHAD is the latest in a sequence of continually evolving computer codes written to effectively utilize massively parallel computer architectures and the latest grid generators for unstructured meshes. Its applications range from automotive design issues such as in-cylinder and manifold flows of internal combustion engines, vehicle aerodynamics, underhood cooling and passenger compartment heating, ventilation, and air conditioning to shock hydrodynamics and materials modeling. CHAD solves the full unsteady Navier-Stoke equations with the k-epsilon turbulence model in three space dimensions. The code has four major features that distinguish it from the earlier KIVA code, also developed at Los Alamos. First, it is based on a node-centered, finite-volume method in which, like finite element methods, all fluid variables are located at computational nodes. The computational mesh efficiently and accurately handles all element shapes ranging from tetrahedra to hexahedra. Second, it is written in standard Fortran 90 and relies on automatic domain decomposition and a universal communication library written in standard C and MPI for unstructured grids to effectively exploit distributed-memory parallel architectures. Thus the code is fully portable to a variety of computing platforms such as uniprocessor workstations, symmetric multiprocessors, clusters of workstations, and massively parallel platforms. Third, CHAD utilizes a variable explicit/implicit upwind method for convection that improves computational efficiency in flows that have large velocity Courant number variations due to velocity of mesh size variations. Fourth, CHAD is designed to also simulate shock hydrodynamics involving multimaterial anisotropic behavior under high shear. The authors will discuss CHAD capabilities and show several sample calculations showing the strengths and weaknesses of CHAD.

  15. Probing Cold Dense Nuclear Matter

    NASA Astrophysics Data System (ADS)

    Subedi, R.; Shneor, R.; Monaghan, P.; Anderson, B. D.; Aniol, K.; Annand, J.; Arrington, J.; Benaoum, H.; Benmokhtar, F.; Boeglin, W.; Chen, J.-P.; Choi, Seonho; Cisbani, E.; Craver, B.; Frullani, S.; Garibaldi, F.; Gilad, S.; Gilman, R.; Glamazdin, O.; Hansen, J.-O.; Higinbotham, D. W.; Holmstrom, T.; Ibrahim, H.; Igarashi, R.; de Jager, C. W.; Jans, E.; Jiang, X.; Kaufman, L. J.; Kelleher, A.; Kolarkar, A.; Kumbartzki, G.; LeRose, J. J.; Lindgren, R.; Liyanage, N.; Margaziotis, D. J.; Markowitz, P.; Marrone, S.; Mazouz, M.; Meekins, D.; Michaels, R.; Moffit, B.; Perdrisat, C. F.; Piasetzky, E.; Potokar, M.; Punjabi, V.; Qiang, Y.; Reinhold, J.; Ron, G.; Rosner, G.; Saha, A.; Sawatzky, B.; Shahinyan, A.; Širca, S.; Slifer, K.; Solvignon, P.; Sulkosky, V.; Urciuoli, G. M.; Voutier, E.; Watson, J. W.; Weinstein, L. B.; Wojtsekhowski, B.; Wood, S.; Zheng, X.-C.; Zhu, L.

    2008-06-01

    The protons and neutrons in a nucleus can form strongly correlated nucleon pairs. Scattering experiments, in which a proton is knocked out of the nucleus with high-momentum transfer and high missing momentum, show that in carbon-12 the neutron-proton pairs are nearly 20 times as prevalent as proton-proton pairs and, by inference, neutron-neutron pairs. This difference between the types of pairs is due to the nature of the strong force and has implications for understanding cold dense nuclear systems such as neutron stars.

  16. Dilatons in Dense Baryonic Matter

    NASA Astrophysics Data System (ADS)

    Lee, Hyun Kyu; Rho, Mannque

    We discuss the role of dilaton, which is supposed to be representing a special feature of scale symmetry of QCD, trace anomaly, in dense baryonic matter. The idea that the scale symmetry breaking of QCD is responsible for the spontaneous breaking of chiral symmetry is presented along the similar spirit of Freund-Nambu model. The incorporation of dilaton field in the hidden local symmetric parity doublet model is briefly sketched with the possible role of dilaton at high density baryonic matter, the emergence of linear sigma model in dilaton limit.

  17. Extracorporeal shockwave application to the distal femur of rabbits diminishes the number of neurons immunoreactive for substance P in dorsal root ganglia L5.

    PubMed

    Hausdorf, Jörg; Lemmens, Marijke A M; Kaplan, Suleyman; Marangoz, Cafer; Milz, Stefan; Odaci, Ersan; Korr, Hubert; Schmitz, Christoph; Maier, Markus

    2008-05-01

    Application of extracorporeal shockwaves to the musculoskeletal system can induce long-term analgesia in the treatment of chronic painful diseases such as calcifying tendonitis of the shoulder, tennis elbow and chronic plantar fasciitis. However, the molecular and cellular mechanisms underlying this phenomenon are largely unknown. Recently it was shown that application of extracorporeal shockwaves to the distal femur of rabbits can lead to reduced concentration of substance P in the shockwaves' focal zone. In the present study we investigated the impact of extracorporeal shockwaves on the production of substance P within dorsal root ganglia in vivo. High-energy shockwaves were applied to the ventral side of the right distal femur of rabbits. After six weeks, the dorsal root ganglia L5 to L7 were investigated with high-precision design-based stereology. The application of extracorporeal shockwaves caused a statistically significant decrease in the mean number of neurons immunoreactive for substance P within the dorsal root ganglion L5 of the treated side compared with the untreated side, without affecting the total number of neurons within this dorsal root ganglion. No effect was observed in the dorsal root ganglia L6 and L7, respectively. These data might further contribute to our understanding of the molecular and cellular mechanisms in the induction of long-term analgesia by extracorporeal shockwave application to the musculoskeletal system.

  18. Oblique impact of dense granular sheets

    NASA Astrophysics Data System (ADS)

    Ellowitz, Jake; Guttenberg, Nicholas; Jaeger, Heinrich M.; Nagel, Sidney R.; Zhang, Wendy W.

    2013-11-01

    Motivated by experiments showing impacts of granular jets with non-circular cross sections produce thin ejecta sheets with anisotropic shapes, we study what happens when two sheets containing densely packed, rigid grains traveling at the same speed collide asymmetrically. Discrete particle simulations and a continuum frictional fluid model yield the same steady-state solution of two exit streams emerging from incident streams. When the incident angle Δθ is less than Δθc =120° +/-10° , the exit streams' angles differ from that measured in water sheet experiments. Below Δθc , the exit angles from granular and water sheet impacts agree. This correspondence is surprising because 2D Euler jet impact, the idealization relevant for both situations, is ill posed: a generic Δθ value permits a continuous family of solutions. Our finding that granular and water sheet impacts evolve into the same member of the solution family suggests previous proposals that perturbations such as viscous drag, surface tension or air entrapment select the actual outcome are not correct. Currently at Department of Physics, University of Oregon, Eugene, OR 97403.

  19. Cleaning of occluded biliary endoprostheses: is shockwave application an alternative to regular stent exchange?

    PubMed

    Farnbacher, Michael J; Kraupa, Werner; Schneider, H Thomas

    2013-01-01

    Occlusion is the major limitation of plastic biliary endoprostheses (PBE), making regular stent exchange necessary. The aim of the in vitro analysis was to evaluate the cleansing effect of shockwave application (SWA) on occluded PBE. Thirty-five PBE removed from 24 patients were analyzed. Three hundred and fifty shockwave pulses were administered every 10 mm along the prosthesis stored in a liquid-filled latex balloon. Occlusion rates were measured before and after SWA. The cleansing rate was calculated in comparison to the native prosthesis. Mean occlusion rate was 76 ± 30% (Range 16-100%) before SWA. Cleansing effect was 47 ± 52% (0-100%) after SWA. Cleaning was complete (100%) in seven (20%) and satisfying (75-99%) in another seven prostheses. Degree of stent occlusion and indwelling time were significantly associated to the cleansing effect. In conclusion, SWA showed a limited cleaning effect in clogged PBE and is no suitable alternative for regular stent replacement to date.

  20. Shock-induced collapse of a gas bubble in shockwave lithotripsy.

    PubMed

    Johnsen, Eric; Colonius, Tim

    2008-10-01

    The shock-induced collapse of a pre-existing nucleus near a solid surface in the focal region of a lithotripter is investigated. The entire flow field of the collapse of a single gas bubble subjected to a lithotripter pulse is simulated using a high-order accurate shock- and interface-capturing scheme, and the wall pressure is considered as an indication of potential damage. Results from the computations show the same qualitative behavior as that observed in experiments: a re-entrant jet forms in the direction of propagation of the pulse and penetrates the bubble during collapse, ultimately hitting the distal side and generating a water-hammer shock. As a result of the propagation of this wave, wall pressures on the order of 1 GPa may be achieved for bubbles collapsing close to the wall. The wall pressure decreases with initial stand-off distance and pulse width and increases with pulse amplitude. For the stand-off distances considered in the present work, the wall pressure due to bubble collapse is larger than that due to the incoming shockwave; the region over which this holds may extend to ten initial radii. The present results indicate that shock-induced collapse is a mechanism with high potential for damage in shockwave lithotripsy.

  1. Effects of extracorporeal shockwave lithotripsy on urinary concentration of epidermal growth factor.

    PubMed

    Baltaci, S; Ozer, G; Soygür, T; Yaman, O; Sarica, K; Müftüoğlu, Y Z; Göğüş, O

    1996-12-01

    In a prospective study, we tried to determine whether extracorporeal shockwave lithotripsy (SWL) has any effect on urinary epidermal growth factor (EGF) concentrations and to investigate whether EGF can be used as a marker for detecting shockwave-induced impairment of distal tubular cells. A total of 12 patients with renal pelvic or caliceal stones < or = 2 cm undergoing anesthesia-free SWL without ancillary measures and a control group of 10 patients without any urologic symptoms were included in this study. The urinary concentrations of EGF were measured by radioimmunoassay before and 4 hours, 24 hours, and 7 days after SWL. Relative urinary EGF concentrations were expressed as the ratio of EGF to creatinine (ng/mL creatinine). The mean urinary EGF concentration (mean +/- standard error) in control subjects and patients with renal pelvic or caliceal stones before SWL was 23.90 +/- 3.15 ng/mL creatinine and 22.18 +/- 6.85 ng/mL creatinine, respectively (p > 0.05). In patients with stones, we found a decrease in urinary EGF concentration 4 hours, 24 hours, and 7 days after SWL. Indeed, 7 days after SWL, the EGF concentration was on average half of the original value, a biologically significant, although not statistically significant, decrease.

  2. F-15B testbed in flight with new sonic shockwave sensor

    NASA Technical Reports Server (NTRS)

    1996-01-01

    NASA Dryden's F-15B testbed aircraft flew several flights recently in support of an experiment to determine the precise location of sonic shockwave development as air passes over an airfoil. The shock location sensor developed by TAO Systems, Hampton, Virginia, utilizes a multi-element hot-film sensor array along with a constant-voltage anemometer and special diagnostic software to pinpoint the exact location of the shock wave and its characteristics as it passes over an aircraft surface. For this experiment, the 45-element sensor was mounted on a Dryden-designed airfoil which was attached to the right side of the underbelly Flight Test Fixture on the F-15B. Tests were flown at transonic speeds of Mach 0.7 to 0.9, and the device isolated the location of the shock wave to within a half-inch. Project officials said that closer spacing of the sensors and underlying pressure orifices would result in even more precise location of shockwave development.

  3. Extracorporeal shockwave therapy (ESWT) in patients with chronic proximal plantar fasciitis.

    PubMed

    Hammer, Dietrich S; Rupp, Stefan; Kreutz, Andreas; Pape, Dietrich; Kohn, Dieter; Seil, Romain

    2002-04-01

    The aim of this study was to compare the effect of extracorporeal shockwave therapy (ESWT) in patients with chronically painful proximal plantar fasciitis with a conventional conservative treatment consisting of nonsteroidal anti-inflammatory drugs, heel cup, orthoses and/or shoe modifications, local steroid injections and electrotherapy. Forty-seven patients (49 feet) with a previously unsuccessful conservative treatment of at least six months were randomized to two groups. Treatment of Group 1 (25 heels) started immediately with three sessions of ESWT (3000 shockwaves/session of 0.2 mJ/mm2) at weekly intervals. In the patients of Group 2 (24 heels) treatment was continued for 12 weeks. After this period they were treated using the protocol of Group 1. No significant difference of pain and walking time after further non-ESWT treatment (three months) was seen. Six months after ESWT pain decreased by 64% to 88% on the visual analog scale (VAS) and the comfortable walking time had increased significantly in both groups.

  4. A special irrigation liquid to increase the reliability of laser-induced shockwave lithotripsy.

    PubMed

    Reichel, E; Paltauf, G; Schmidt-Kloiber, H; Groke, K

    1992-01-01

    For the laser-induced shockwave lithotripsy (LISL) the laser-pulses of a Q-switched Nd:YAG laser produce an optical breakdown in the irrigation liquid surrounding the urinary stone. Subsequently high-pressure shockwaves are emitted causing stone fragmentation. Since the LISL is an endoscopic technique, problems arise from the transmission of the laser pulses through optical fibers. The intensity threshold for an optical breakdown in commonly used saline solution amounts to 21 GW/cm2, in optical silica fibers, to about 3 GW/cm2. Therefore bare fibers cannot be used without being destroyed by a breakdown. So we have developed an irrigation liquid by adding small quantities of metal ions to saline solution to lower the threshold intensity. The most suitable ion was Fe3+ in a concentration of 0.02 mmol/l, which shows a lowering to 5 GW/cm2. In combination with a spherically shaped fiber exit the intensities that have to be transmitted are below the threshold of the fiber material. Using this irrigation liquid the overall reliability of the method could be significantly increased and several stone fragmentations can be performed with a single optical fiber.

  5. [Extracorporeal shockwave lithotripsy in the treatment of gallbladder lithiasis. The first 109 patients].

    PubMed

    Correia, A P; Ribeiro, L C; Contente, L F; de Moura, M C

    1993-07-01

    The AA report their 15-month experience with extracorporeal shock-wave lithotripsy (ESWL) in the treatment of gallbladder stones (GS). The selection criteria included symptomatic patients, with 1 to 3 radiolucent stones in a functioning gallbladder. All patients were put on adjuvant therapy with 10 mg/Kg weight/day of ursodeoxycholic acid (ursodiol). ESWL sessions were performed in an ambulatory setting, using high-energy shock-waves (mean: 23 Kv) until fragments < or = 4mm were obtained, if possible. By the end of December 1992, 109 patients had completed the ESWL protocol, undergoing a total of 265 sessions (mean: 2.4 sessions per patient, variation 1-5). The stone-free (SF) rates and respective 95% confidence intervals were 31% (22%-43%) at 6 months and 59% (38%-76%) at 1 year of follow-up. For the subset of patients with a single stone < or = 2 cm (n = 59), were 47% (33%-63%) at 6 months and 77% (40%-95%) at 1 year. The most significant complication was acute biliary pancreatitis, of which we report 4 cases (4%). They were always mild and non-complicated. There was no mortality. The AA conclude that ESWL is a safe and effective treatment for selected patients with GS.

  6. [Treatment of calculi not easily seen with radiology using extracorporeal shockwave lithotripsy. Value of contrast media].

    PubMed

    Lancina Martín, J A; Arrabal Martín, M; Camacho Martínez, E; Gómez Núñez, E; García Pérez, M

    1991-01-01

    Currently, most calculi can be treated with shockwave extracorporeal lithotrity regardless their location within the urinary apparatus or their physico-chemical features. In order to optimize results only medical criteria for patient's selection should be taken into account. Certain type of calculi can obstruct adequate radioscopic viewing by not allowing correct centring for shockwave emission. The problem can be overcome by using echography or other contrast procedures. Of a total 514 patients treated in our Unit with ESWL, execution of contrast procedures was necessary in 18 cases (3.5%) in order to allow adequate viewing of the calculi. Calculi in 10 patients were midly radiopacque, uric acid in 4, and bone-superimposed in the remaining 4. This technical manoeuvre allowed in all cases a good centring of the calculi. After a two months follow-up. lithiasis is absent in 15 patients and only 2 present expellable lithiatic fragments. It can therefore be concluded that the use of contrast procedures, both through i.v. or a catheter, is a simple, safe and well tolerated procedure allowing convenient viewing of those calculi, also followed by good results after ESWL treatment.

  7. Shockwave treatment for medial tibial stress syndrome in athletes; a prospective controlled study.

    PubMed

    Moen, M H; Rayer, S; Schipper, M; Schmikli, S; Weir, A; Tol, J L; Backx, F J G

    2012-03-01

    Objective The purpose of this study was to describe the results of two treatment regimens for medial tibial stress syndrome (MTSS); a graded running programme and the same running programme with additional shockwave therapy (extracorporeal shockwave therapy; ESWT). Design A prospective observational controlled trial. Setting Two different sports medicine departments. Participants 42 athletes with MTSS were included. Intervention Patients from one hospital were treated with a graded running programme, while patients from the other hospital were treated with the same graded running programme and focused ESWT (five sessions in 9 weeks). Main Outcome Measures Time to full recovery (the endpoint was being able to run 18 min consecutively without pain at a fixed intensity). Results The time to full recovery was significantly faster in the ESWT group compared with the patients who only performed a graded running programme, respectively 59.7±25.8 and 91.6±43.0 days (p=0.008). Conclusions This prospective observational study showed that MTSS patients may benefit from ESWT in addition to a graded running programme. ESWT as an additional treatment warrants further investigation in a prospective controlled trial with the addition of randomisation and double blinding.

  8. Renal nerves mediate changes in contralateral renal blood flow after extracorporeal shockwave lithotripsy.

    PubMed

    Connors, Bret A; Evan, Andrew P; Willis, Lynn R; Simon, Jay R; Fineberg, Naomi S; Lifshitz, David A; Shalhav, Arieh L; Paterson, Ryan F; Kuo, Ramsay L; Lingeman, James E

    2003-01-01

    Renal blood flow falls in both kidneys following delivery of a clinical dose of shockwaves (SW) (2000 SW, 24 kV, Dornier HM3) to only one kidney. The role of renal nerves in this response was examined in a porcine model of renal denervation. Six-week-old pigs underwent unilateral renal denervation. Nerves along the renal artery of one kidney were identified, sectioned and painted with 10% phenol. Two weeks later the pigs were anesthetized and baseline renal function was determined using inulin and PAH clearances. Animals then had either sham-shockwave lithotripsy (SWL) (group 1), SWL to the innervated kidney (group 2) or SWL to the denervated kidney (group 3). Bilateral renal function was again measured 1 and 4 h after SWL. Both kidneys were then removed for analysis of norepinephrine content to validate the denervation. Renal plasma (RPF) flow was significantly reduced in shocked innervated kidneys (group 2) and shocked denervated kidneys (group 3). RPF was not reduced in the unshocked denervated kidneys of group 2. These observations suggest that renal nerves play a pivotal role in modulating the vascular response of the contralateral unshocked kidney to SWL, but only a partial role, if any, in modulating that response in the shocked kidney.

  9. In vitro fragmentation of gallstones: comparison of electrohydraulic, electromagnetic and piezoelectric shockwave lithotripters.

    PubMed

    Schneider, H T; Fromm, M; Ott, R; Janowitz, P; Swobodnik, W; Neuhaus, H; Ell, C

    1991-08-01

    To compare the fragmentation efficiency of three different shockwave systems, 63 human gallstone triplets were disintegrated in vitro using an electrohydraulic (MPL 9000, Dornier), an electromagnetic (Lithostar Plus, Siemens) and a piezoelectric (Piezolith 2300, R. Wolf) lithotripter. Since each stone triplet was obtained from the same gallbladder, the concrements of one such set were identical in physicochemical parameters. According to the maximal diameter, the calculi were divided into group A (6 to 15 mm) and group B (16 to 30 mm). Shockwave application was terminated when residual fragments measured 4 mm or less. Forty-five triplets were fragmented at energy settings mainly used in clinical treatment of patients with gallbladder stones (MPL 9000: 20 kV; Lithostar Plus: setting 9 (maximal); Piezolith 2300: setting 3). The fragmentation endpoint was achieved in group A (n = 3 x 36) with the Piezolith 2300 after median 150 (range = 50 to 500) pulses and with the Lithostar Plus after 150 (50 to 750) pulses compared with 500 (50 to 1,500) pulses using the MPL 9000 (p less than 0.01). In group B (n = 3 x 9) the Lithostar Plus (median = 750, range = 250 to 1,250 pluses) required fewer discharges than the Piezolith 2300 (1,250, 250 to 2,500 pulses; p less than 0.05) and the MPL (1,500, 500 to 1,600 [upper limit] pulses; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

  10. [Improvement of extracorporeal shockwave cholelithotripsy in the comprehensive treatment of cholelithiasis].

    PubMed

    Bagaudinov, K G; Saidov, S S; Garilevich, B A; Zubkov, A D; Abdulaev, R A; Ovakimian, G S

    2007-01-01

    The method of shockwave distant lithotripsy (DL) has been used since 1985. However, many facets of this problem have not been solved yet, because large fragments of the stone remain after its destruction, and focused shock waves (FSW) damage the gallbladder (GB). The aim of this study was to determine possibilities of effective distant destruction of gall stones, to reveal negative consequences of the effects of FSW on the gallbladder (GB) and the surrounding tissues, as well as development and perfection of DL technique. The established parameters of FSW were used to develop the new Lithotriptor Compact. By now, 53 patients with cholelithiasis aged 18 to 55 have been treated by DC. The procedure was performed without general anesthesia. A thousand to 3500 shockwave impulses were applied to each stone. All patients had received litholytic therapy and treatment directed towards metabolic normalization, the functional state of the GB, and prevention of recurrent stone formation, prior to DL. In total, 116 DL sessions (2.2 sessions per a patient) were performed. A positive effect as a result of the complex treatment of cholelithiasis using DL method was achieved in 47 (88.7%) of the patients. There were no complications. In 3 patients (5.7%) recurrence of gallstones was found two years after DL sessions. Correctly selected parameters of FSW and DL technology allow for effective destruction of GB stones, while conservative therapy favors their passage through the biliary tract and fast litholysis of remaining stone fragments.

  11. Effect of extracorporeal shockwave lithotripsy on plasma and urine endothelin concentrations.

    PubMed

    Esen, A A; Gezer, S; Gemalmaz, A; Kirkali, G; Kirkali, Z

    1996-08-01

    Since the first reports of extracorporeal shockwave lithotripsy (SWL), there have been increasing numbers of articles in the literature documenting renal blood flow impairment and blood pressure elevation as complications. However, little is known about the pathophysiology and prevention of these complications. In this prospective study, the influence of high-energy shockwaves on plasma and urine endothelin concentrations was investigated in 20 patients with renal stones. The patients were randomly assigned to receive a calcium channel blocker, 10 mg of nitrendipine (Bypress; Bayer) (N = 10) 2 hours before SWL or no medication (control group; N = 10). Blood samples were taken just before and 1 minute after application of 3000 shocks. Urine samples were collected by ureteral catheters. The plasma endothelin-1 concentrations were significantly elevated after SWL in the control group (P = 0.003). On the other hand, nitrendipine significantly reduced plasma endothelin concentrations after SWL (P = 0.003). No significant change was observed in urine samples and blood pressure measurements. These results suggest that endothelin release after SWL may be a cause for lithotripsy-induced hemodynamic changes. Medical prevention with calcium channel blockers warrants further investigation.

  12. Soft-tissue effects of biliary extracorporeal shockwave lithotripsy in swine.

    PubMed

    Malone, D E; Becker, C D; Reich, D; Quenville, N F; Burhenne, H J

    1989-09-01

    This study investigates the soft-tissue effects of biliary extracorporeal shockwave lithotripsy (BESWL) using a recently developed lithotripter, which consists of an electromagnetic shockwave generator and an integrated ultrasonic targeting system. Sixteen swine, evenly divided into four groups, underwent BESWL. One group had one BESWL session targeted on the gallbladder and another group had two BESWL sessions targeted on the gallbladder. The third group had one BESWL session targeted on implanted gallbladder stones and the fourth group had one BESWL session targeted on the region of the common bile duct (CBD). Half of each group were sacrificed on the day of lithotripsy and half 1 week later. Post-mortem examinations were performed. Each implanted gallstone had fragmented. There were no findings attributable to BESWL in 11 animals. Three animals had pulmonary haemorrhagic spots (the largest was 10 mm in diameter) and one had a submucosal CBD petechia; these findings were attributable to BESWL. In two animals, microscopic haemorrhage associated with bronchopneumonia (usually present in our pig population) was more prominent than usual. This was possibly attributable to BESWL. The swine's deep posterior costophrenic sulcus makes it difficult to avoid the lung base during BESWL in swine. We conclude that this BESWL device can fragment gallstones without causing clinically significant soft-tissue damage.

  13. Safety and effectiveness of extracorporeal shockwave therapy: results of a rabbit model of chronic osteomyelitis.

    PubMed

    Gollwitzer, Hans; Roessner, Michaela; Langer, Rupert; Gloeck, Tobias; Diehl, Peter; Horn, Carsten; Stemberger, Axel; von Eiff, Christof; Gerdesmeyer, Ludger

    2009-04-01

    Extracorporeal shockwave therapy (ESWT) is applied successfully in various orthopedic disorders. Since shockwaves have demonstrated significant bactericidal effectiveness in vitro, safety and effectiveness of ESWT in vivo were evaluated in a rabbit model of osteomyelitis. Chronic osteomyelitis was induced by injecting sodium morrhuate and Staphylococcus aureus into the proximal tibia of 12 New Zealand white rabbits. Four and five wk after the initial operation, soft focused ESWT was applied twice to the infected limbs. Clinical parameters and laboratory values were followed and blood samples were taken for culture before and 30 min after ESWT. Following sacrifice after 8 wk, lungs, spleen and kidneys were studied histologically for signs of sepsis and secondary infection. Tibial osteomyelitis was assessed clinically, and by radiologic, microbiologic and histologic procedures. Signs of bacterial spreading were not detectable after ESWT, neither in blood cultures nor in histologic analyses of representative organs. Temperature, body weight, C-reactive protein and white blood cell levels also remained unchanged after ESWT. Of particular interest, histologic scores of osteomyelitis were significantly decreased in the ESWT-group compared to the untreated control (p = 0.019). However, S. aureus was still detectable in tissue samples of all animals. This is the first study investigating the effects of ESWT applied to infected target areas. ESWT of infected bone did neither induce bacterial spreading nor worsening of infection, and the results suggest the reported treatment protocol of ESWT to be beneficial in the treatment of chronic bone infections.

  14. Experimental study of pulsed power driven radiative shockwaves in noble gases

    NASA Astrophysics Data System (ADS)

    Skidmore, J.; Lebedev, S.; Suzuki-Vidal, F.; Bland, S.; Swadling, G.; Burdiak, G.; Hall, G.; Patankar, S.; de Grouchy, P.; Suttle, L.; Bennett, M.; Pickworth, L.; Khoory, E.; Smith, R.; Rodriguez, R.; Gil, J.

    2013-10-01

    The use of plastic disks coated with a thin film of Aluminium has been investigated as a control mechanism for the shockwave formed from a radial foil z-pinch in the presence of an ambient medium. Experiments were carried out on the MAGPIE (1.4 MA, 250 ns rise time) facility at Imperial College London. The configuration produces a strong radiative shockwave driven with constant velocity (>25 km/s) for long time (>400 ns) and spatial scales (cm). Experimental results demonstrate scaling of shock compression opposite to that found in 1D radiation hydrodynamic simulations. Evidence of a thermal instability in the post-shock cooling region is linked to a decrease in compression for higher atomic masses due to increased radiative cooling. Increases in post-shock temperature and ionization have been measured with decreased radial distance from a strongly cooling hydrodynamic jet. Regions of observed thermal instability for Xenon and Krypton agree with those expected from evaluation of theoretical cooling functions. Institute of Shock Physics, Imperial College London.

  15. Working mechanism of extracorporeal shockwave therapy in non-urological disciplines

    NASA Astrophysics Data System (ADS)

    Schaden, Wolfgang

    2005-04-01

    For 32 years of extracorporeal shockwave lithotripsy (ESWL) only the mechanical strength of shockwaves were of clinical interest. For use in orthopaedics, the absence of dangerous long term effects (malignant degeneration, etc.) is the only important message. The mechanical model tries to explain the effect of shock waves by the provocation of microleasions in the tissue stimulating repairing processes. First doubts on this mechanical model came up when Schaden (2001) could show, that less energy is more efficient in the treatment of non-unions. Due to the basic research of the last years knowledge increased about the microbiological effects. Under the influence of shock waves the change of permeability of cell membranes and the liberation of free radicals was reported. Also the production of nitric oxide (NO) and different growth factors like vascular endothelial growth factor (VEGF), bone morphogenetic proteins (BMP), transforming growth factor-beta 1 (TGF-b1), insulin-like growth factor-I (IGF-I) etc. was observed. The biological model tries to explain the effect of shock waves by stimulating the ingrowth of blood vessels and liberation of growth factors. Under the influence of shock waves, biological tissues seem to be able to produce important substances to initiate healing processes.

  16. Shock-induced collapse of a gas bubble in shockwave lithotripsy

    PubMed Central

    Johnsen, Eric; Colonius, Tim

    2008-01-01

    The shock-induced collapse of a pre-existing nucleus near a solid surface in the focal region of a lithotripter is investigated. The entire flow field of the collapse of a single gas bubble subjected to a lithotripter pulse is simulated using a high-order accurate shock- and interface-capturing scheme, and the wall pressure is considered as an indication of potential damage. Results from the computations show the same qualitative behavior as that observed in experiments: a re-entrant jet forms in the direction of propagation of the pulse and penetrates the bubble during collapse, ultimately hitting the distal side and generating a water-hammer shock. As a result of the propagation of this wave, wall pressures on the order of 1 GPa may be achieved for bubbles collapsing close to the wall. The wall pressure decreases with initial stand-off distance and pulse width and increases with pulse amplitude. For the stand-off distances considered in the present work, the wall pressure due to bubble collapse is larger than that due to the incoming shockwave; the region over which this holds may extend to ten initial radii. The present results indicate that shock-induced collapse is a mechanism with high potential for damage in shockwave lithotripsy. PMID:19062841

  17. Generation of Shock-Wave Disturbances at Plasma-Vapor Bubble Oscillation

    NASA Astrophysics Data System (ADS)

    Kuznetsova, N. S.; Yudin, A. S.; Voitenko, N. V.

    2015-11-01

    The complex physical and mathematical model describing all steps of plasma-vapor bubble evolution in the system of the water-ground condensed media is presented. Discharge circuit operation, discharge plasma channel expansion, its transformation into the vapor-plasma bubble and its pulsation, pressure wave generation and propagation of the mechanical stress waves in the ground are self-consistently considered in the model. The model allows investigation of the basic laws of stored energy transformation into the discharge plasma channel, next to the plasma-vapor bubble and transformation of this energy to the energy of pressure wave compressing the surrounding ground. Power characteristics of wave disturbances generated by gas-vapor bubble oscillation in liquid depending on the circuit parameters are analyzed for the prediction of the ground boundary displacement. The dynamics of the shock-wave propagation in water-ground condensed media depending on the rate of the plasma channel energy release is investigated. Simulation of the shock-wave phenomena at a plasma-vapor bubble oscillation in condensed media consecutively describes the physical processes underlying technology for producing piles by electro-discharge stuffing. The quantitative model verified by physical experimental tests will allow optimization of pulse generator parameters and electrode system construction of high-voltage equipment.

  18. Large-Eddy Simulation of Shock-Wave Boundary Layer Interaction and its Control Using Sparkjet

    NASA Astrophysics Data System (ADS)

    Yang, Guang; Yao, Yufeng; Fang, Jian; Gan, Tian; Lu, Lipeng

    2016-06-01

    Large-eddy simulation (LES) of an oblique shock-wave generated by an 8° sharp wedge impinging onto a spatially-developing Mach 2.3 turbulent boundary layer and their interactions has been carried out in this study. The Reynolds number based on the incoming flow property and the boundary layer displacement thickness at the impinging point without shock-wave is 20,000. The detailed numerical approaches are described and the inflow turbulence is generated using the digital filter method to avoid artificial temporal or streamwise periodicity. Numerical results are compared with the available wind tunnel PIV measurements of the same flow conditions. Further LES study on the control of flow separation due to the strong shock-viscous interaction is also conducted by using an active control actuator “SparkJet” concept. The single-pulsed characteristics of the control device are obtained and compared with the experiments. Instantaneous flowfield shows that the “SparkJet” promotes the flow mixing in the boundary layer and enhances its ability to resist the flow separation. The time and spanwise averaged skin friction coefficient distribution demonstrates that the separation bubble length is reduced by maximum 35% with the control exerted.

  19. Development of a PVDF low-cost shock-wave hydrophone

    NASA Astrophysics Data System (ADS)

    Travakkoli, J.; Birer, A.; Cathignol, D.

    1996-05-01

    During a few past years a series of shock-wave generators for lithotripsy and/or tissue destruction studies have been developed in our laboratory. Based on the experiences in shock wave measurements and the drawbacks in existing hydrophones, we have developed a very low-cost, wideband, reproducible shock-wave hydrophone. The key element of this device is the rapidly mounting, disposable PVDF membrane. This is a commercially available PVDF shock gauge which is poled by a patented cyclic poling technique. To obtain the widest possible bandwidth, we have adopted a special coplanar membrane design. The PVDF filmis sandwiched between the surfaces of a P.V.C. and a metallic plate of brass which the latter is in contact with the surrounding medium. On the other hand, the active lead is isolated from medium and it is in contact with an isolating liquid (degassed petroleum) held in a cylindrical chamber over the membrane. By the incorporation of this design, the hydrophone can be used for shock wave measurements even in conductive media like different physiological liquids, with a negligible change of sensitivity.

  20. Al 1s-2p Absorption Spectroscopy of Shock-Wave Heating and Compression in Laser-Driven Planar Foil

    SciTech Connect

    Sawada, H.; Regan, S.P.; Radha, P.B.; Epstein, R.; Li, D.; Goncharov, V.N.; Hu, S.X.; Meyerhofer, D.D.; Delettrez, J.A.; Jaanimagi, P.A.; Smalyuk, V.A.; Boehly, T.R.; Sangster, T.C.; Yaakobi, B.; Mancini, R.C.

    2009-05-19

    Time-resolved Al 1s-2p absorption spectroscopy is used to diagnose direct-drive, shock-wave heating and compression of planar targets having nearly Fermi-degenerate plasma conditions (Te ~ 10–40 eV, rho ~ 3–11 g/cm^3) on the OMEGA Laser System [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. A planar plastic foil with a buried Al tracer layer was irradiated with peak intensities of 10^14–10^15 W/cm^2 and probed with the pseudocontinuum M-band emission from a point-source Sm backlighter in the range of 1.4–1.7 keV. The laser ablation process launches 10–70 Mbar shock waves into the CH/Al/CH target. The Al 1s-2p absorption spectra were analyzed using the atomic physic code PRISMSPECT to infer Te and rho in the Al layer, assuming uniform plasma conditions during shock-wave heating, and to determine when the heat front penetrated the Al layer. The drive foils were simulated with the one-dimensional hydrodynamics code LILAC using a flux-limited (f =0.06 and f =0.1) and nonlocal thermal-transport model [V. N. Goncharov et al., Phys. Plasmas 13, 012702 (2006)]. The predictions of simulated shock-wave heating and the timing of heat-front penetration are compared to the observations. The experimental results for a wide variety of laser-drive conditions and buried depths have shown that the LILAC predictions using f = 0.06 and the nonlocal model accurately model the shock-wave heating and timing of the heat-front penetration while the shock is transiting the target. The observed discrepancy between the measured and simulated shock-wave heating at late times of the drive can be explained by the reduced radiative heating due to lateral heat flow in the corona.

  1. Ionic Transport Coefficients of Dense Plasmas without Molecular Dynamics.

    PubMed

    Daligault, Jérôme; Baalrud, Scott D; Starrett, Charles E; Saumon, Didier; Sjostrom, Travis

    2016-02-19

    We present a theoretical model that allows a fast and accurate evaluation of ionic transport properties of realistic plasmas spanning from warm and dense to hot and dilute conditions, including mixtures. This is achieved by combining a recent kinetic theory based on effective interaction potentials with a model for the equilibrium radial density distribution based on an average atom model and the integral equations theory of fluids. The model should find broad use in applications where nonideal plasma conditions are traversed, including inertial confinement fusion, compact astrophysical objects, solar and extrasolar planets, and numerous present-day high energy density laboratory experiments. PMID:26943540

  2. Ionic Transport Coefficients of Dense Plasmas without Molecular Dynamics

    NASA Astrophysics Data System (ADS)

    Daligault, Jérôme; Baalrud, Scott D.; Starrett, Charles E.; Saumon, Didier; Sjostrom, Travis

    2016-02-01

    We present a theoretical model that allows a fast and accurate evaluation of ionic transport properties of realistic plasmas spanning from warm and dense to hot and dilute conditions, including mixtures. This is achieved by combining a recent kinetic theory based on effective interaction potentials with a model for the equilibrium radial density distribution based on an average atom model and the integral equations theory of fluids. The model should find broad use in applications where nonideal plasma conditions are traversed, including inertial confinement fusion, compact astrophysical objects, solar and extrasolar planets, and numerous present-day high energy density laboratory experiments.

  3. Uniformly dense polymeric foam body

    DOEpatents

    Whinnery, Jr., Leroy

    2003-07-15

    A method for providing a uniformly dense polymer foam body having a density between about 0.013 g/cm.sup.3 to about 0.5 g/cm.sup.3 is disclosed. The method utilizes a thermally expandable polymer microsphere material wherein some of the microspheres are unexpanded and some are only partially expanded. It is shown that by mixing the two types of materials in appropriate ratios to achieve the desired bulk final density, filling a mold with this mixture so as to displace all or essentially all of the internal volume of the mold, heating the mold for a predetermined interval at a temperature above about 130.degree. C., and then cooling the mold to a temperature below 80.degree. C. the molded part achieves a bulk density which varies by less then about .+-.6% everywhere throughout the part volume.

  4. Particle-based simulations of bilayer membranes: self-assembly, structural analysis, and shock-wave damage

    NASA Astrophysics Data System (ADS)

    Steinhauser, Martin O.; Schindler, Tanja

    2016-08-01

    We report on the results of particle-based, coarse-grained molecular dynamics simulations of amphiphilic lipid molecules in aqueous environment where the membrane structures at equilibrium are subsequently exposed to strong shock waves, and their damage is analyzed. The lipid molecules self-assemble from unbiased random initial configurations to form stable bilayer membranes, including closed vesicles. During self-assembly of lipid molecules, we observe several stages of clustering, starting with many small clusters of lipids, gradually merging together to finally form one single bilayer membrane. We find that the clustering of lipids sensitively depends on the hydrophobic interaction h_c of the lipid tails in our model and on temperature T of the system. The self-assembled bilayer membranes are quantitatively analyzed at equilibrium with respect to their degree of order and their local structure. We also show that—by analyzing the membrane fluctuations and using a linearized theory— we obtain area compression moduli K_A and bending stiffnesses κ_B for our bilayer membranes which are within the experimental range of in vivo and in vitro measurements of biological membranes. We also discuss the density profile and the pair correlation function of our model membranes at equilibrium which has not been done in previous studies of particle-based membrane models. Furthermore, we present a detailed phase diagram of our lipid model that exhibits a sol-gel transition between quasi-solid and fluid domains, and domains where no self-assembly of lipids occurs. In addition, we present in the phase diagram the conditions for temperature T and hydrophobicity h_c of the lipid tails of our model to form closed vesicles. The stable bilayer membranes obtained at equilibrium are then subjected to strong shock waves in a shock tube setup, and we investigate the damage in the membranes due to their interaction with shock waves. Here, we find a transition from self

  5. The effects of treatment the avascular necrosis of the femoral head with extracorporeal focused shockwave therapy.

    PubMed

    Kusz, Damian; Franek, Andrzej; Wilk, Robert; Dolibog, Paweł; Błaszczak, Edward; Wojciechowski, Piotr; Król, Piotr; Dolibog, Patrycja; Kusz, Błażej

    2012-01-01

    Background.Avascular necrosis of the femoral head continues to represent a major challenge for the orthopaedist and trauma surgeon. A fully effective method of treatment is yet to be introduced. After femoral head collapse, only total hip replacement can help the patient. Our study aims to assess the effects of treatment of avascular necrosis of the femoral head with extra corporeal focused shockwave therapy.Material and methods. A prospective study was carried out in patients with avascular necrosis of the femoral head, ARCO stage I-III, diagnosed by MRI imaging. Shock waves are applied under x-ray guidance. Four points are marked on the skin above the lesion. Each spot receives a dose of 1500 pulses at an energy flux density of 0.4 mJ/mm2 and a frequency of 4 Hz. Each patient undergoes 5 therapy sessions. A posturometric and stabilometric assessment is carried out before and after the therapy. Other examinations include a tensometric evaluation of the strength of the treated limb, and an assessment of pain intensity (VAS scale)and hip function (Harris hip score). Follow-up visits are scheduled at 6 weeks and 3, 6 and 12 months post-treatment.Results. Nine patients were treated with shockwave therapy at the Department of Orthopaedics and Musculoskeletal Traumatology, Medical Faculty, Medical University of Silesia, between 5 May 2011 and 1 June 2012. The patients demonstrated pain reduction and improved mobility of the treated joint (VAS score decreasing from 6.75 +/- 0.71 to 2.5 +/- 1.7; Harris hip score increasing from 55.21 +/- 15.45 to 89.21 +/- 8.26). Tensometric platform testing carried out after the treatment revealed a statistically significant difference between mean velocity of the centre of pressure (CoP) movement when walking with eyes open and closed (p<0.05) and mean CoP movement along the x (walking with eyes closed) and y (free standing with eyes closed) axes.Conclusions. 1. Extracorporeal focused shockwave therapy resulted in considerable

  6. Extracorporeal shockwave therapy for Peyronie's disease does not correct penile deformity.

    PubMed

    Strebel, R T; Suter, S; Sautter, T; Hauri, D

    2004-10-01

    To evaluate whether extracorporeal shockwave therapy (ESWT) offers an effective treatment for the main complications of Peyronie's disease (PD), that is, penile deformity and angulation, painful erection and most importantly unsatisfied sexual intercourse. From September 1999 to January 2001, 52 patients with PD were treated with ESWT. Pain during erection was assessed with a visual analogue scale. Penile deviation was determined by photographs with a goniometer. Five treatment sessions were performed at weekly intervals. Each consisted of 3000 shockwaves with an emission frequency of 120 shockwaves/min and a mean intensity of 0.17 mJ/mm(2). A Storz Minilith SL 1 with integrated inline ultrasound probe was used. In all, 52 patients were evaluated 6 weeks after ESWT for early follow-up. Before ESWT intercourse was difficult or impossible for 40 men; 29 patients suffered mainly from penile deformity, 14 from painful erection and eight mainly from loss of distal rigidity. A total of 30 patients mentioned painful erection before treatment. In 28 patients (93%) pain reduction was achieved. A total relief of pain was observed in 19 patients (63%). Mean pain score dropped from 4.2 to 1.3 in patients who suffered predominantly from painful erections. Intercourse satisfaction improved in 11 patients after therapy. Mean angulation before (40 degrees ) and after (37 degrees ) ESWT did not change significantly. Late follow-up after 11.1 months (4-17 months) could be completed in 36 patients. In total, 19 men reported that ESWT improved their PD. Of these, 16 noted no change. Only one of the patients noticed a worsening of his disease during or after treatment. Complication rate was low with only minor side effects such as minimal skin bruising; one urethral bleeding occurred. ESWT did reduce pain during erection in patients suffering mainly from painful erection due to PD. However, penile angulation did not improve significantly in our setup and thus intercourse difficulties

  7. The performance of dense medium processes

    SciTech Connect

    Horsfall, D.W.

    1993-12-31

    Dense medium washing in baths and cyclones is widely carried out in South Africa. The paper shows the reason for the preferred use of dense medium processes rather than gravity concentrators such as jigs. The factors leading to efficient separation in baths are listed and an indication given of the extent to which these factors may be controlled and embodied in the deployment of baths and dense medium cyclones in the planning stages of a plant.

  8. The isolated perfused kidney: an in vitro test system for evaluation of renal tissue damage induced by high-energy shockwaves sources.

    PubMed

    Bergsdorf, Th; Thüroff, S; Chaussy, Ch

    2005-09-01

    Most of our knowledge of shockwave-induced renal damage is based on animal experiments and clinical observation. We developed a tissue model using isolated porcine kidneys perfused with Berliner Blau dye in physiologic saline using a Ureteromat Perez-Castro peristaltic pump connected to the renal artery. Reproducible results were obtained under a variety of experimental conditions. Further refinements of the model might consist of interposition of tissue layers in the shockwave path or simulation of ventilatory movements.

  9. Comparison of treatment of renal calculi by open surgery, percutaneous nephrolithotomy, and extracorporeal shockwave lithotripsy.

    PubMed Central

    Charig, C R; Webb, D R; Payne, S R; Wickham, J E

    1986-01-01

    This study was designed to compare different methods of treating renal calculi in order to establish which was the most cost effective and successful. Of 1052 patients with renal calculi, 350 underwent open surgery, 350 percutaneous nephrolithotomy, 328 extracorporeal shockwave lithotripsy (ESWL), and 24 both percutaneous nephrolithotomy and ESWL. Treatment was defined as successful if stones were eliminated or reduced to less than 2 mm after three months. Success was achieved in 273 (78%) patients after open surgery, 289 (83%) after percutaneous nephrolithotomy, 301 (92%) after ESWL, and 15 (62%) after percutaneous nephrolithotomy and ESWL. Comparative total costs to the NHS were estimated as 3500 pounds for open surgery, 1861 pounds for percutaneous nephrolithotomy, 1789 pounds for ESWL, and 3210 pounds for both ESWL and nephrolithotomy. ESWL caused no blood loss and little morbidity and is the cheapest and quickest way of returning patients to normal life. PMID:3083922

  10. Extracorporeal shockwave therapy for plantar fasciitis and other musculoskeletal conditions utilizing the Ossatron--an update.

    PubMed

    Wilner, Joel M; Strash, Walter W

    2004-07-01

    Extracorporeal shockwave therapy for treatment of plantar fasciitis and other areas of the body has been well documented since the early 1990s. A high level of efficacy and patient satisfaction after undergoing electrohydraulic shock wave treatments has been reported not only for plantar fasciopathy but other musculoskeletal indications. Electrohydraulic devices have a bimodal response: early suppression of nocioceptor reactivity followed by subsequent target tissue remodeling and healing through neovascularization and recruitment of new tissue target specific cells. Both responses are not present with low energy electromagnetic devices. The focus of this article is treatment of chronic proximal plantar fasciitis; however, other pathologies of the lower extremity demonstrate great promise for this emerging technology.

  11. Experience with 500 extracorporeal shockwave lithotripsy patients using a low-cost unit: the "Econolith".

    PubMed

    Simon, D

    1995-06-01

    The Econolith (Medispec Ltd.) is a modular extracorporeal shockwave (SWL) system that uses the spark gap as its source for lithotripsy. In this study, the immediate and late results and complications in 500 patients (640 treatments) treated with this machine during the last 2 years were summarized. An average fragmentation rate of 86% was achieved after the first treatment. A stone-free situation at 3 months was achieved in 75% of the cases; 18% had small (< 5mm) fragments, and 7% had larger fragments. Auxiliary procedures were required in 8% of the patients. Minor complications such as hematuria, colic, and urinary tract infection were seen in 6% of the patients. The Econolith system is safe and effective. Its mobility and low cost enable any urologist to use this technology even with a low monthly turnover of patients.

  12. Extracorporeal shockwave therapy (ESWT) in the treatment of plantar fasciitis--a biometrical review.

    PubMed

    Böddeker, R; Schäfer, H; Haake, M

    2001-01-01

    The application of extracorporeal shockwave therapy (ESWT) as a treatment for conservatively unsuccessfully treated plantar fasciitis has experienced a rapid increase over the last years. However, the efficacy of ESWT has not yet been established unequivocally, as published studies have led to inconsistent results. Furthermore, reviews on clinical trials on ESWT are either not up to date, incomplete, or methodologically inadequate. As a consequence, a systematic literature search was conducted which yielded 21 relevant articles on ESWT in the treatment of plantar fasciitis. These were rated according to biometrical criteria for the conduct of therapeutic trials based on international guidelines. None of the rated trials fulfilled all of the criteria, and it is concluded that at this point the efficacy of ESWT can be neither confirmed nor excluded. Randomised and controlled clinical trials are required to adequately estimate the value of ESWT as a treatment for plantar fasciitis.

  13. Electrohydraulic extracorporeal non-water bath shock-wave lithotripsy of gallstones: two years' experience.

    PubMed

    Frick, T W; Hoffmann, R; Schlumpf, R; Largiadèr, F

    1991-01-01

    A prospective study was performed to evaluate the effectiveness of extracorporeal shockwave lithotripsy (ESWL) using a non-water bath lithotripter in combination with oral chemolitholysis on gallstone clearance. Patients were treated without general anesthesia or parenteral analgesia. We treated 74 patients selected according to the widely accepted criteria. Only 2 patients could not be sufficiently treated because of pain. After a 2 year period, 24 (32%) patients showed complete stone clearance, 35 (47%) patients had residual fragments, 5 (7%) patients underwent cholecystectomy, 2 (3%) patients were lost to follow up, and 8 (11%) patients discontinued the treatment before fragment clearance. According to the life-table estimate, 77% of our patients with successful ESWL and uncomplicated oral chemolitholysis are stonefree after 1 year. We consider the major advantage of this nonsurgical treatment of gallstone disease is that general anesthesia or parenteral analgesia has become unnecessary.

  14. Percutaneous debulking of staghorn stones combined with extracorporeal shockwave lithotripsy: results and complications.

    PubMed

    Puppo, P; Bottino, P; Germinale, F; Caviglia, C; Ricciotti, G; Giuliani, L

    1988-01-01

    The results and complications of 122 percutaneous debulking of staghorn stones are carefully reviewed, discriminating between dilated and not dilated kidneys. Percutaneous debulking can be defined as satisfactory in about 70% of the cases. In the remaining 30% of the cases (mostly not dilated kidneys) it has got little or no results. The overall complication rate is quite low and most of the common complications can be prevented. Percutaneous procedures in nondilated kidneys have an overall complication rate highly superior to that in dilated kidneys. It should be preferable to treat as many staghorn stones as possible in nondilated kidneys with staged extracorporeal shockwave lithotripsy (ESWL) monotherapy, stenting the ureter and monitoring the urinary infection. Struvite stones are best suitable for stented ESWL because of their fragility. In case of cystine or oxalate monohydrate staghorn stone open surgery might be preferable in virgin patients, but it is often refused by the patients.

  15. Fertility measures in women after extracorporeal shockwave lithotripsy of distal ureteral stones.

    PubMed

    Erturk, E; Ptak, A M; Monaghan, J

    1997-10-01

    Long-term effects of extracorporeal shockwave lithotripsy (SWL) on female fertility remain a concern. Thirty-nine women of childbearing age who were treated for distal ureteral stones were surveyed. The mean age of these women was 33 years, and the average stone size was 6.9 mm. The mean calculated radiation exposure to the ovaries and the uterus was 7.53 and 10.9 mSv, respectively. Ten women (26%) attempted to become pregnant. No fertility problems were noted in these women, and 11 healthy babies were delivered. These preliminary findings provide further information regarding the safety of SWL in the treatment of distal ureteral stones in women of reproductive age.

  16. Comparison of treatment of renal calculi by open surgery, percutaneous nephrolithotomy, and extracorporeal shockwave lithotripsy.

    PubMed

    Charig, C R; Webb, D R; Payne, S R; Wickham, J E

    1986-03-29

    This study was designed to compare different methods of treating renal calculi in order to establish which was the most cost effective and successful. Of 1052 patients with renal calculi, 350 underwent open surgery, 350 percutaneous nephrolithotomy, 328 extracorporeal shockwave lithotripsy (ESWL), and 24 both percutaneous nephrolithotomy and ESWL. Treatment was defined as successful if stones were eliminated or reduced to less than 2 mm after three months. Success was achieved in 273 (78%) patients after open surgery, 289 (83%) after percutaneous nephrolithotomy, 301 (92%) after ESWL, and 15 (62%) after percutaneous nephrolithotomy and ESWL. Comparative total costs to the NHS were estimated as 3500 pounds for open surgery, 1861 pounds for percutaneous nephrolithotomy, 1789 pounds for ESWL, and 3210 pounds for both ESWL and nephrolithotomy. ESWL caused no blood loss and little morbidity and is the cheapest and quickest way of returning patients to normal life.

  17. Extracorporeal shockwave treatment of osteonecrosis of the femoral head in systemic lupus erythematosis.

    PubMed

    Lin, Po-Chun; Wang, Ching-Jen; Yang, Kuender D; Wang, Feng-Sheng; Ko, Jih-Yang; Huang, Chung-Cheng

    2006-09-01

    This article reported a case of systemic lupus erythematosis (SLE) with osteonecrosis of the femoral heads (ONFH-3) successfully treated with a novel extracorporeal shockwave treatment (ESWT). The follow-up at 3 years showed that both hips had no pain on activities for daily living. Magnetic resonance image (MRI) showed substantial reduction in bone marrow edema and no further collapse of the lesions. Radiographs and MRIs showed no change in the staging of the disease. ESWT provided beneficial effects for hips affected by ONFH in patients with SLE. This novel treatment modality resulted in significant pain relief and functional improvement of the hip and reduction in bone marrow edema in our patient. It appeared that ESWT might have the potential to curtail the progression of the disease and to delay the need for total hip arthroplasty in the very young patients contracted with SLE.

  18. [The value of shockwave therapy in treatment of humero-radial epicondylitis].

    PubMed

    Vogt, W; Dubs, B

    2001-01-01

    Numerous therapies exist for the treatment of radial Epicondylitis. A new treatment, Extracorporal Shock-Wave Therapy (ESWT) has recently been proposed. Based on a review of the medical literature various mechanisms of action are presented. Except for the treatment of conditions of the urinary system, ESWT is controversial. Scientific proof of enhanced efficacy of ESWT compared to other treatments of radial Epicondylitis is still lacking. Prospective, randomized follow-up studies of large patient populations under standardized technical conditions are needed. Based on current knowledge, ESWT of radial Epicondylitis should only be applied if three conditions are fulfilled: 1) the diagnosis of radial Epicondylitis has been ascertained, 2) conservative therapies for at least one year failed, and 3) the only alternative is surgery.

  19. Extracorporeal shockwave therapy (ESWT)--First choice treatment of fracture non-unions?

    PubMed

    Schaden, Wolfgang; Mittermayr, Rainer; Haffner, Nicolas; Smolen, Daniel; Gerdesmeyer, Ludger; Wang, Ching-Jen

    2015-12-01

    Fracture non-unions are still a challenging problem in orthopedics. The treatment of non-unions remains highly individualized, complex, and demanding. In most countries the surgical approach with debridement of the non-union gap, anatomical reduction and appropriate osteosynthesis along with autologous bone grafting is considered as the standard of care. One of the very first non-urologic applications of extracorporeal shockwave treatment (ESWT) concerned non-healing fractures. Since the early 1990ties the knowledge of the working mechanism has increased enormously. The purpose of this review article is to demonstrate by peer-reviewed literature in conjunction with our own experiences that ESWT can be an efficient, non-invasive, almost complication-free and cost effective alternative to surgical treatment of non-healing fractures.

  20. [Experience with extracorporeal shockwave lithotripsy based on 5 years' clinical use].

    PubMed

    Chaussy, C; Fuchs, G

    1985-11-01

    After 6 years of experimental research at the Departments of Urology and Surgical Research of the Ludwig-Maximilian University in Munich, extracorporeal shock-wave lithotripsy (ESWL) was introduced into clinical use in 1980. Uniquely successful and increasingly requested by stone patients, the method soon became widespread. Currently more than 70 lithotriptors are in operation worldwide and over 30,000 treatments have been carried out successfully. Clinical experience in all centers has proved the safety, reliability and reproducibility of the method. Currently, approximately 70% of nonselected stone patients are eligible to receive ESWL treatment and, when combined with endourological procedures, more than 95% of patients can benefit from this method and thus avoid open surgery.

  1. Extracorporeal shockwave lithotripsy for treatment of intrahepatic stones: in vitro and in vivo studies.

    PubMed

    Ker, C G; Hwang, C H; Chen, J S; Lee, K T; Sheen, P C

    1993-04-01

    In vitro, bile duct stones, mostly comprising calcium bilirubinate, are readily fragmented by extracorporeal shockwave lithotripsy (ESWL). In the case of intrahepatic stones, ESWL is effective if the stones float freely in the bile, but if the stones completely fill, or are impacted within, the hepatic duct or bile duct, attempts at fragmentation will end in failure. Three patients with intrahepatic stones were treated with ESWL, and effectively fragmented. The stone fragments passed out spontaneously through T-tube sinus tract, PTDC sinus tract and the sphincter of Oddi as shown in the second cholangiogram. No specific complication was noted in our experimental and clinical experience. We believe that ESWL for fragmentation of biliary stones is technically reliable. The problem of the passage of these fragmented stones is considered; if necessary, it can be overcome by endoscopic means.

  2. Extracorporeal shockwave lithotripsy for urinary calculi in autosomal dominant polycystic kidney disease.

    PubMed

    Delakas, D; Daskalopoulos, G; Cranidis, A

    1997-06-01

    Autosomal dominant polycystic kidney disease (ADPKD) is an inherited systemic disorder. Renal stones have a high rate of occurrence among patients with ADPKD and are a significant cause of morbidity in this disorder. Thirteen patients with ADPKD and symptomatic or obstructive renal stones presented to our hospital for evaluation and treatment with extracorporeal shockwave lithotripsy (SWL). A total of 16 renal units were treated. The auxiliary procedures included placement of a double-J stent in nine kidneys when the stone was larger than 8 mm in diameter. Eleven patients (85%) were stone free 3 months after lithotripsy; a second treatment was necessary in two patients. We conclude that SWL can be used as a primary management tool for renal stones in patients with ADPKD.

  3. Original lithotomy positioning for transperineal extracorporeal shockwave lithotripsy for distal ureteric calculi with Tripter X1.

    PubMed

    Andrianne, R; Vandeberg, C; Bonnet, P; Nicolas, H; Coppens, L; Bouffioux, C; de Leval, J

    1992-01-01

    Extracorporeal shockwave lithotripsy (ESWL) has been initially designed for stones located in the kidney and the upper ureter. Our lithotripter is no exception. Its components (the table and the orientation of the semi-ellipsoid reflector) are adapted for the treatment of kidney or lumbar ureter stones. However, the elements forming the unit of treatment (the table, the C-arm and the Tripter) can be modified in such a way that focalization of stones of the lower ureter becomes possible through a perineal exposure. The aim is to avoid the pelvic bone shield while a good focalization of the stone is realized. From June 1989 to March 1991, 35 patients were treated for distal ureteric stones by ESWL in this original positioning.

  4. Outcome assessment of double-J stents during extracorporeal shockwave lithotripsy of small solitary renal calculi.

    PubMed

    Low, R K; Stoller, M L; Irby, P; Keeler, L; Elhilali, M

    1996-08-01

    The utility of indwelling double-J ureteral stents during extracorporeal shockwave lithotripsy (SWL) of renal calculi is ill defined. We evaluated 179 patients treated with SWL for small (< 20 mm in diameter) solitary renal calculi with (N = 27) or without (N = 152) indwelling ureteral stents. There was no significant difference in the stone-free rates at 1 month (both 52%) and 3 months (61% nonstented group v 67% stented group; P = 0.45) or in the retreatment rates (13.3% nonstented group v 14.8% stented group; P = 0.60). The incidence and severity of pain/renal colic were similar for the two treatment groups. There was minimal morbidity associated with SWL in either group. Placement of double-J stents for the purpose of improving stone-free rates, alleviating pain, or preventing ureteral obstruction in conjunction with SWL of solitary renal calculi < 20 mm in diameter is unnecessary.

  5. [Extracorporeal shockwave therapy in treatment of epicondylitis humeri radialis. A current overview].

    PubMed

    Böddeker, I; Haake, M

    2000-05-01

    In the past, extracorporeal shock-wave therapy (ESWT) has been used increasingly as a treatment for conservatively unsuccessfully treated radiohumeral epicondylitis. However, published reviews of clinical trials on the efficacy of ESWT have led to inconsistent results and are outdated or methodologically inadequate. As a consequence, a systematic literature search was conducted which yielded 20 relevant papers that described trials on the efficacy of ESWT in the treatment of radiohumeral epicondylitis. These were rated according to biometrical criteria for the conduct of therapeutic trials. None of the rated trials fulfilled all of the criteria, and it is concluded that the efficacy of ESWT in the treatment of epidondylitis can presently be neither confirmed nor excluded.

  6. Experience with 395 extracorporeal shockwave lithotripsy in the treatment of renal and ureteric calculi.

    PubMed

    Tan, H M; Cheung, H S

    1990-06-01

    Three hundred and ninety five cases in 358 consecutive patients (male-232, female-126) with renal and ureteric stones were treated with extracorporeal shockwave lithotripsy (ESWL) from March to November 1988. They either had ESWL alone, or in combination with stone manipulation or debulking percutaneous nephrolithotripsy (PCNL). Seventy five percent of the stones were found in the pelvicalyceal system and 25% in the ureter. Seventy-six percent of the stones were less than 25mm size. Two hundred and ninety (79%) cases were followed up to three months. Two hundred and forty nine (85.9%) cases were stone free and 36 (12.4%) had residual sand less than 3mm size. Five (1.7%) cases failed to fragment with ESWL monotherapy and were salvaged by either percutaneous or ureteroscopic intervention. None of the cases required any open surgery intervention.

  7. Extracorporeal shockwave lithotripsy: first 1000 cases at the London Stone Clinic.

    PubMed

    Das, G; Dick, J; Bailey, M J; Fletcher, M S; Webb, D R; Kellett, M J; Whitfield, H N; Wickham, J E

    1987-10-10

    One thousand patients underwent extracorporeal shockwave lithotripsy for renal and ureteric calculi at this clinic. An overall success rate of 91.8% was achieved (stone free or less than 2 mm fragments at three months) and for stones measuring 1 cm 96.3%. Lithotripsy produced extremely low morbidity, and no deaths have occurred at the clinic. Patients who had lithotripsy alone had a mean hospital stay of three days and in most instances were able to perform their full range of activities on discharge. Planned combination of lithotripsy with minimally invasive endourological procedures such as percutaneous nephrolithotomy and ureterorenoscopy has allowed us to extend the range of treatable cases to include large stones. Prophylactic use of Double-J ureteric stents in selected cases has reduced the incidence of obstruction by stone fragments after lithotripsy, thereby decreasing morbidity and hospital stay.

  8. In situ extracorporeal shockwave lithotripsy of distal ureteral stones: parameters for therapeutic success.

    PubMed

    Mattelaer, P; Schröder, T; Fischer, N; Jakse, G

    1994-01-01

    Between January and December 1989, 123 patients with distal ureteral stones were treated with in situ extracorporeal shockwave lithotripsy (ESWL) using a modified HM3 Dornier lithotriptor. One hundred and three patients (83.7%) were stone-free, 20 patients (16.3%) had small residual stones (< 1 mm2) that passed spontaneously. In situ ESWL treatment alone was successful in 88 of the 103 stone-free patients (85.4%). Fifty-six (54.4%) needed 1 ESWL session, 26 (25.2%) needed 2 ESWL sessions. Nineteen of the 123 patients (15.4%) needed auxiliary endourological measures. The results of ESWL treatment were correlated to pretherapeutically identified parameters such as stone size, radiopacity, outer contour, shape, inner structure, biochemical analysis of the stones and grade of dilatation of the upper urinary tract. The results prove that size (> or = 75 mm2), radiopacity and grade of dilatation have a direct correlation to the difficulty to disintegrate ureteral stones.

  9. Limitations of extracorporeal shockwave lithotripsy for lower caliceal stones: anatomic insight.

    PubMed

    Sampaio, F J; Aragao, A H

    1994-08-01

    In addition to gravity-dependent position, we suppose that other particular anatomic features may be important in the retention of stone debris in lower calices after extracorporeal shockwave lithotripsy (SWL). We analyzed the inferior-pole collecting system anatomy in 146 three-dimensional polyester resin corrosion endocasts of the pelviocaliceal system. In 74% of the cases, there was an angle of greater than 90 degrees formed between the lower infundibulum and the renal pelvis, and in 26%, the angle was 90 degrees or less. In 60%, there was a lower infundibulum 4 mm or larger in diameter. The inferior pole was drained by multiple calices disposed in two rows in 57% of the cases and by one midline caliceal infundibulum in 43%. We believe that the physician must appreciate these anatomic features when considering SWL to treat calculi located in lower calices.

  10. [Extracorporeal shockwave lithotripsy of gallstones: how many patients are suitable for it?].

    PubMed

    Rambow, A; Staritz, M; Klose, P; Thelen, M; Meyer zum Büschenfelde, K H

    1989-06-01

    The proportion of patients with gallbladder stones suitable for extracorporeal shockwave lithotripsy (ESWL) was analysed prospectively in 200 patients aged 17-76 years (62 males, 138 females) with symptomatic cholecystolithiasis. Criteria for inclusion were clinical symptoms, solitary stones (diameter 10-30 mm) or up to three stones with comparable total volume, contractile gallbladder, no calcification of stones, normal biliary tract anatomy. To check these criteria a step-by-step diagnostic procedure was instituted which consisted of history, ultrasonography with contractility test, abdominal X-ray film, computed tomography measurement of stone density, and endoscopic retrograde cholangiography. Only 19 patients fulfilled the criteria. The others had to be excluded because of history (35), stone size or number (73), impaired gallbladder contractility (27), calcified stone (30), pigment content (12), and/or biliary tract anatomy. Thus only a surprisingly small percentage (about 10%) of patients with symptomatic gallbladder stones is suitable for ESWL.

  11. Report on the first 1000 patients treated at St Thomas' Hospital by extracorporeal shockwave lithotripsy.

    PubMed

    Palfrey, E L; Bultitude, M I; Challah, S; Pemberton, J; Shuttleworth, K E

    1986-12-01

    Since March 1985, over 1000 patients have been treated on the lithotripter at St Thomas' Hospital. Since it is the only machine in the country offering treatment to National Health Service patients at no cost to the referring Health Authority, there has been a heavy demand for treatment and 97% of referrals have been accepted. Analysis of the first 1000 patients shows extracorporeal shockwave lithotripsy (ESWL) to be a safe procedure with a low morbidity rate and no mortality. The number of patients who were stone-free 3 months after treatment was low (44.1%) compared with the numbers reported in other series. The most likely reasons for this are the poor follow-up rate (48.9%), the stringent criteria for the diagnosis of "stone-free" and a possible skewed referral and follow-up pattern.

  12. Piezolith extracorporeal shockwave lithotripsy: the Hotel-Dieu de France experience.

    PubMed

    Merhej, S; Nemr, E; Armache, K; Chalouhy, E; Chaiban, R; Moukarzel, M; Khoury, R

    1994-10-01

    A total of 1500 patients underwent treatment with the Wolf Piezolith 2300 extracorporeal shockwave lithotripter for renal, ureteral, and bladder stones. Follow-up data were available at 3 months for 1435 patients. At that time, the overall stone-free rate was 82.7%: 82.4% for patients with renal stones, 81.0% for those with ureteral stones, and 100% for those with bladder stones. The overall success rate was 92.3%: 93.8% for patients with renal stones, 87.1% for those with ureteral stones, and 100% for those with bladder stones. The auxiliary treatment rate was 14.9%, and the retreatment rate was 53%. The effectiveness quotient was 49.2%. The Wolf Piezolith 2300 is an effective treatment for most stones smaller than 30 mm.

  13. Hydrodynamic shockwave tenderization effects using a cylinder processor on early deboned broiler breasts.

    PubMed

    Claus, J R; Schilling, J K; Marriott, N G; Duncan, S E; Solomon, M B; Wang, H

    2001-07-01

    In separate experiments, chicken broiler breasts were deboned (45 min postmortem, 52 min, respectively) and either exposed to high pressure hydrodynamic shockwaves (HSW) 25 min after deboning (77 min postmortem) or after 24 h of storage (4°C) respectively, and compared to companion control breasts. HSW were produced in a cylindrical HSW processor with 40-g explosive. Warner-Bratzler shear (WBS) values of the HSW breasts treated at 77 min postmortem were not different than the controls. HSW treatment decreased (P<0.05) the WBS values of the stored and cooked breasts by 42.0% as compared to non-treated controls. Cooking losses were not affected by HSW. In general, raw and cooked color characteristics (CIE L*a*b*) were not affected by the HSW. HSW treatment at 25 min after deboning (77 min postmortem) may require a higher pressure front or delayed treatment after postmortem aging to improve tenderness.

  14. Comparative evaluation of general, epidural and spinal anaesthesia for extracorporeal shockwave lithotripsy.

    PubMed

    Rickford, J K; Speedy, H M; Tytler, J A; Lim, M

    1988-03-01

    The results of a prospective randomised evaluation of general anaesthesia (GA), epidural anaesthesia (EA) and spinal anaesthesia (SA) for extracorporeal shockwave lithotripsy are presented. GA provided speed and reliability but resulted in a high incidence of postoperative nausea, vomiting and sore throat. Both regional techniques conferred the advantages of an awake, cooperative patient, but EA required a longer preparation time than SA and more supplementary treatment with fentanyl or midazolam. A major drawback associated with the use of SA was a 42% incidence of postspinal headache. All three techniques were associated with hypotension on placement in the hoisl; bath immersion resulted in significant rises in blood pressure in the EA and SA groups and a more variable (overall non-significant) response in the GA group.

  15. [Extracorporeal shockwave lithotripsy in children. Complications and long-term results].

    PubMed

    Gschwend, J E; Paiss, T; Gottfried, H W; Hautmann, R E

    1995-07-01

    ESWL of urinary stones is a well-established treatment in adult patients. The treatment of urinary stones in children has gained increasing importance in recent years. From 1987 to 1993, a series of 27 children with urolithiasis in all parts of the urinary tract were treated by ESWL. Treatment was performed with general anaesthesia or analgosedation. During the treatment no complications occurred. On average, 34 sessions of ESWL, with 2165 shockwaves and 22.3 kV energy, were performed. Minor early complications, such as fever, pain and hydronephrosis, were observed in 7 patients. The overall stone clearance rate was 92%. Stone recurrence occurred in only 1 patient. There were no late complications, such as malfunction of the kidney, skeletal deformation or hypertension after 38 months of follow up. In conclusion, ESWL is the treatment of first choice in paediatric urolithiasis.

  16. EXPLOMET 90 international conference on shock-wave and high-strain-rate phenomena in materials

    NASA Astrophysics Data System (ADS)

    Meyers, Marc A.; Murr, Lawrence E.; Staudhammer, Karl P.

    1992-01-01

    This report describes the major components and activities of EXPLOMET 90, an international conference on shock-wave and high-strain-rate effects held at UCSD August 12-17, 1990. The conference was attended by approximately 200 scientists and engineers from throughout the world and was enriched by invited/keynote lectures by a group of world-renowned scientists. Over 110 talks were presented and twenty posters were displayed. The proceedings are being published by M. Dekker and will appear in February 1992. Sessions were devoted to the following topics: (1) High Strain Rate Deformation; (2) Shock and Combustion Synthesis; (3) Dynamic Consolidation; (4) Shaped Charge Phenomena; (5) Shear Localization; (6) Dynamic Fracture; (7) Shock Phenomena and Superconductivity; (8) Shock Waves and Shock Loading; (9) Shock and Dynamic Phenomena in Ceramics; and (10) Explosive Welding and Metalworking.

  17. Quantum molecular dynamics simulation of shock-wave experiments in aluminum

    SciTech Connect

    Minakov, D. V.; Khishchenko, K. V.; Fortov, V. E.; Levashov, P. R.

    2014-06-14

    We present quantum molecular dynamics calculations of principal, porous, and double shock Hugoniots, release isentropes, and sound velocity behind the shock front for aluminum. A comprehensive analysis of available shock-wave data is performed; the agreement and discrepancies of simulation results with measurements are discussed. Special attention is paid to the melting region of aluminum along the principal Hugoniot; the boundaries of the melting zone are estimated using the self-diffusion coefficient. Also, we make a comparison with a high-quality multiphase equation of state for aluminum. Independent semiempirical and first-principle models are very close to each other in caloric variables (pressure, density, particle velocity, etc.) but the equation of state gives higher temperature on the principal Hugoniot and release isentropes than ab initio calculations. Thus, the quantum molecular dynamics method can be used for calibration of semiempirical equations of state in case of lack of experimental data.

  18. Shock-wave compression of silica gel as a model material for comets

    NASA Astrophysics Data System (ADS)

    Arasuna, Akane; Okuno, Masayuki; Chen, Liliang; Mashimo, Tsutomu; Okudera, Hiroki; Mizukami, Tomoyuki; Arai, Shoji

    2016-07-01

    A shock-wave compression experiment using synthesized silica gel was investigated as a model for a comet impact event on the Earth's surface. The sample shocked at 20.7 GPa showed considerable structural changes, a release of water molecules, and the dehydration of silanol (Si-OH) that led to the formation of a new Si-O-Si network structure containing larger rings (e.g., six-membered ring of SiO4 tetrahedra). The high aftershock temperature at 20.7 GPa, which could be close to 800 °C, influenced the sample structure. However, some silanols, which were presumed to be the mutually hydrogen-bonded silanol group, remained at pressures >20.7 GPa. This type of silanol along with a small number of water molecules may remain even after shock compression at 30.9 GPa, although the intermediate structure of the sample recovered was similar to that of silica glass.

  19. Relationship among shock-wave velocity, particle velocity, and adiabatic exponent for dry air

    NASA Astrophysics Data System (ADS)

    Kim, In H.; Hong, Sang H.; Jhung, Kyu S.; Oh, Ki-Hwan; Yoon, Yo K.

    1991-07-01

    Using the results of the detailed numerical calculations, it is shown that the relationship between the shock-wave velocity U sub s and the particle velocity U sub p for shock-compressed dry air can be represented accurately by the linear relation U sub s = a(P0) + b(P0)U sub p in a wide range of U sub p (U sub p = 2 to 9 ) km/s and initial pressure P0 = 10 to the -6th to 1 atm, where a and b are given by the cubic polynomials of log10P0. Based on the linear U sub s - U sub p relation, an analytic expression has been obtained for the adiabatic exponent gamma as a function of particle velocity.

  20. Studies of collisionless shockwaves using high-power laser pulses in laboratories

    NASA Astrophysics Data System (ADS)

    Yuan, Da-Wei; Li, Yu-Tong

    2015-01-01

    The remarkable experimental progress in the studies of collisionless shockwave (CS) in laboratories employing high-power lasers is briefly reviewed. The results show that CS can be generated in laser-produced plasmas due to the micro-turbulence associated with instabilities. CS is one of the most important astronomical phenomena. It has been found in supernova remnants (SNRs), Sun-Earth space, etc. This paper focuses on CS in ways relevant to SNRs. Laboratory astrophysics (LA), a new interdisciplinary frontier of astrophysics, plasma and laser physics, has developed rapidly in recent years. As an accessory to the astronomical observation, LA experimenters can closely study some astronomical events scaled-down to controllable phenomena. Project supported by the National Basic Research Program of China (Grant No. 2013CBA01501) and the National Natural Science Foundation of China (Grant No. 11135012).

  1. Study of shockwave method for diagnosing the radiation fields of laser-driven gold hohlraums

    NASA Astrophysics Data System (ADS)

    Li, Yongsheng; Lan, Ke; Huo, Wenyi; Lai, Dongxian; Gao, Yaoming; Pei, Wenbing

    2013-11-01

    Besides the routinely used broad-band x-ray spectrometer (Dante or SXS), ablative shock-wave method is often used to diagnose the radiation fields of laser-driven Hohlraums. The x-ray ablation process of Aluminum and Titanium is studied numerically with a 1-D radiation hydrodynamic code RDMG [F. Tinggui et al., Chin. J. Comput. Phys. 16, 199 (1999)], based on which a new scaling relation of the equivalent radiation temperature with the ablative shock velocity in Aluminum plates is proposed, and a novel method is developed for determining simultaneously the radiation temperature and the M-band (2-4 keV) fraction in laser-driven gold Hohlraums.

  2. Extracorporeal shockwave-induced expression of lubricin in tendons and septa.

    PubMed

    Zhang, Dafang; Kearney, Cathal J; Cheriyan, Thomas; Schmid, Thomas M; Spector, Myron

    2011-11-01

    Lubricin, a lubricating glycoprotein that facilitates tendon gliding, is upregulated by mechanical as well as biochemical stimuli, prompting this study of its induction by extracorporeal shockwave therapy (ESWT). The objective of this study was to characterize and quantify the effect of ESWT on lubricin expression in tendons and septa in a rat model. Hindlimbs of six rats were treated with low-dose ESWT and those of another six with high-dose ESWT, using contralateral limbs as controls. After 4 days, resected samples were processed for immunolocalization of lubricin using a purified monoclonal antibody. ESWT was found to increase lubricin expression in both low-dose and high-dose ESWT-treated tendons and also in septa. Lubricin expression generally increased with increasing dose of ESWT. Increased lubricin expression may contribute to the beneficial effects of ESWT in providing pain and symptom relief in musculoskeletal disorders by decreasing erosive wear.

  3. The Shock-Wave Patterns on a Cranked-Wing Configuration

    NASA Technical Reports Server (NTRS)

    Sammonds, Robert I.

    1960-01-01

    The shock-wave patterns of a complex configuration with cranked cruciform wings and a cone-cylinder body were examined to determine the interaction of the body bow wave with the flow field about the wing. Also of interest, was the interaction of the forward (760 sweptback) wing leading-edge wave with the rear (600 sweptback) wing leading-edge wave. The shadowgraph pictures of the model in free flight at a Mach number of 4.9, although not definitive, appear to indicate that the body bow wave crosses the outer wing panel after first being refracted either by the leading-edge wave of the 600 sweptback wing or by pressure fields in the flow crossing the wing.

  4. CHARADE: A characteristic code for calculating rate-dependent shock-wave response

    SciTech Connect

    Johnson, J.N.; Tonks, D.L.

    1991-01-01

    In this report we apply spatially one-dimensional methods and simple shock-tracking techniques to the solution of rate-dependent material response under flat-plate-impact conditions. This method of solution eliminates potential confusion of material dissipation with artificial dissipative effects inherent in finite-difference codes, and thus lends itself to accurate calculation of elastic-plastic deformation, shock-to-detonation transition in solid explosives, and shock-induced structural phase transformation. Equations are presented for rate-dependent thermoelastic-plastic deformation for (100) planar shock-wave propagation in materials of cubic symmetry (or higher). Specific numerical calculations are presented for polycrystalline copper using the mechanical threshold stress model of Follansbee and Kocks with transition to dislocation drag. A listing of the CHARADE (for characteristic rate dependence) code and sample input deck are given. 26 refs., 11 figs.

  5. Free-electron-laser-induced shock-wave control and mechanistic analysis using pulse control

    SciTech Connect

    Kanai, Taizo; Yoshihashi-Suzuki, Sachiko; Awazu, Kunio

    2008-11-01

    The wavelength of the free electron laser (FEL) in Osaka University can be continuously varied in the range of 5.0-20.0 {mu}m. The FEL has a double-pulse structure, consisting of a train of macropulses of pulse duration 12 {mu}s. Each macropulse contains a train of 330 micropulses of pulse duration 5 ps. The tunability and picosecond pulses afford new medical and biological applications. However, a macropulse of long pulse duration leads to undesirable secondary effects. Precise control of the macropulse duration is essential for the high-precision applications of the FEL. An FEL pulse control system using acousto-optic modulators has been developed to investigate mechanical (shock-wave) effects of the FEL on living tissues. With this system, we have controlled photoinduced shock waves and determine the mechanism of interaction during FEL-induced tissue ablation.

  6. Shockwaves increase T-cell proliferation and IL-2 expression through ATP release, P2X7 receptors, and FAK activation.

    PubMed

    Yu, Tiecheng; Junger, Wolfgang G; Yuan, Changji; Jin, An; Zhao, Yi; Zheng, Xueqing; Zeng, Yanjun; Liu, Jianguo

    2010-03-01

    Shockwaves elicited by transient pressure disturbances are used to treat musculoskeletal disorders. Previous research has shown that shockwave treatment affects T-cell function, enhancing T-cell proliferation and IL-2 expression by activating p38 mitogen-activated protein kinase (MAPK) signaling. Here we investigated the signaling pathway by which shockwaves mediate p38 MAPK phosphorylation. We found that shockwaves at an intensity of 0.18 mJ/mm(2) induce the release of extracellular ATP from human Jurkat T-cells at least in part by affecting cell viability. ATP released into the extracellular space stimulates P2X7-type purinergic receptors that induce the activation of p38 MAPK and of focal adhesion kinase (FAK) by phosphorylation on residues Tyr397 and Tyr576/577. Elimination of released ATP with apyrase or inhibition of P2X7 receptors with the antagonists KN-62 or suramin significantly weakens FAK phosphorylation, p38 MAPK activation, IL-2 expression, and T-cell proliferation. Conversely, addition of exogenous ATP causes phosphorylation of FAK and p38 MAPK. Silencing of FAK expression also reduces these cell responses to shockwave treatment. We conclude that shockwaves enhance p38 MAPK activation, IL-2 expression, and T-cell proliferation via the release of cellular ATP and feedback mechanisms that involve P2X7 receptor activation and FAK phosphorylation.

  7. Extracorporeal shockwave therapy (ESWT) ameliorates healing of tibial fracture non-union unresponsive to conventional therapy.

    PubMed

    Haffner, Nicolas; Antonic, Vlado; Smolen, Daniel; Slezak, Paul; Schaden, Wolfgang; Mittermayr, Rainer; Stojadinovic, Alexander

    2016-07-01

    Tibial non-unions are common cause of demanding revision surgeries and are associated with a significant impact on patients' quality of life and health care costs. Extracorporeal shockwave therapy (ESWT) has been shown to improve osseous healing in vitro and in vivo. The main objective of present study was to evaluate the efficacy of ESWT in healing of tibial non-unions unresponsive to previous surgical and non-surgical measures. A retrospective multivariant analysis of a prospective open, single-centre, clinical trial of tibia non-union was conducted. 56 patients with 58 eligible fractures who met the FDA criteria were included. All patients received 3000-4000 impulses of electrohydraulic shockwaves at an energy flux density of 0.4mJ/mm(2) (-6dB). On average patients underwent 1.9 times (±1.3SD) surgical interventions prior to ESWT displaying the rather negatively selected cohort and its limited therapy responsiveness. In 88.5% of patients receiving ESWT complete bone healing was observed after six months irrespective of underlying pathology. The multivariant analysis showed that time of application is important for therapy success. Patients achieving healing received ESWT earlier: mean number of days between last surgical intervention and ESWT (healed - 355.1 days±167.4SD vs. not healed - 836.7 days±383.0SD; p<0.0001). ESWT proved to be a safe, effective and non-invasive treatment modality in tibial non-unions recalcitrant to standard therapies. The procedure is well tolerated, time-saving, lacking side effects, with potential to significantly decrease health care costs. Thus, in our view, ESWT should be considered the treatment of first choice in established tibial non-unions.

  8. Ultrasonic imaging for extracorporeal shockwave lithotripsy: analysis of factors in successful treatment.

    PubMed

    Kiely, E A; Madigan, D; Ryan, P C; Butler, M R

    1990-08-01

    The emergence of real-time ultrasonic imaging for extracorporeal shockwave lithotripsy poses questions regarding the factors and techniques which facilitate stone imaging for clinicians with no previous practical experience in ultrasonography. The ability of these clinicians to assess when stone disintegration has been achieved also needs to be confirmed. A wide range of data was recorded from each of 2688 lithotripsy treatments performed over a 2-year period using the EDAP LT.01 ultrasound-imaged piezoelectric lithotriptor. An analysis of these data was performed using a comprehensive microcomputer-based statistics package. The mean time taken for stone imaging and positioning was reduced from 11.2 to 7.5 min over the 2-year period. Obese patients and those with renal pelvic stones were best imaged in a lateral position. Overall there was no difference in percentage stone disintegration or clearance between treatments in the supine or lateral positions, but a significant reduction in the clearance of small caliceal stones resulted when the lateral position was used. Factors associated with a significantly greater percentage of stone disintegration and clearance included pain experienced by the patient during fine adjustment of the processing head during treatment, acoustic focus attenuation and widening and acoustic shadow widening as detected by the urologist at the end of treatment. Among the factors not associated with significant alterations in the percentage of stone disintegration or clearance were the lithotriptor operator, the side or site of the calculus, obesity and shockwave frequency or power. This study confirmed the ability of urologists to develop expertise in ultrasonography for renal stone imaging and to interpret successfully the subtle signs of stone disintegration.

  9. Extracorporeal shockwave lithotripsy for lower pole calculi smaller than one centimeter.

    PubMed

    Chaussy, Christian; Bergsdorf, Thorsten

    2008-10-01

    Extracorporeal shockwave lithotripsy (ESWL) has revolutionized the treatment of urinary calculi and became the accepted standard therapy for the majority of stone patients. Only for stones located in the lower calix, ESWL displayed a limited efficacy. Since the stone-free rate seemed to be preferential, endoscopic maneuvers like percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS) have been proposed as the primary approach for this stone localization.Stone size seems to be the most important parameter in regard to the stone-free rate, whereas anatomical characteristics of the lower pole collecting system are discussed controversial. Various studies show a good stone clearance between 70-84% for stones up to 1 cm in diameter. Additional physical and medical measures are suitable to improve treatment results. Stone remnants after ESWL, defined as clinical insignificant residual fragments (CIRF) will not cause problems in every case and will pass until up to 24 months after treatment; in total 80-90% of all patients will become stone-free or at least symptom-free.When complete stone-free status is the primary goal, follow-up examinations with new radiological technologies like spiral CT show that the stone-free rate of ESWL and endoscopically treated patients (RIRS) does not differ significantly. However, in comparison to endoscopic stone removal, shockwave therapy is noninvasive, anesthesia-free and can be performed in an outpatient setup. Therefore, ESWL remains the first choice option for the treatment of lower caliceal stones up to 1 cm. The patient will definitely favour this procedure.

  10. Safety and efficacy of low intensity shockwave (LISW) treatment in patients with erectile dysfunction

    PubMed Central

    Ruffo, A.; Capece, M.; Prezioso, D.; Romeo, G.; Illiano, E.; Romis, L.; Lauro, G. Di; Iacono, F.

    2015-01-01

    ABSTRACT The primary goal in the management strategy of a patient with ED would be to determine its etiology and cure it when possible, and not just to treat the symptoms alone. One of the new therapeutic strategies is the use of low intensity extracorporeal shockwave (LISW) therapy. The mechanism of shockwave therapy is not completely clear. It is suggested that LISW induces neovascularization and improvement of cavernosal arterial flow which can lead to an improvement of erectile function by releasing NO, VEGF and PCNA. Materials and Methods: 31 patients between February and June 2013 with mild to severe ED and non-Phosphodiesterase 5 inhibitors responders were enrolled. Patients underwent four weekly treatment sessions. During each session 3600 shocks at 0.09mJ/ mm2 were given, 900 shocks at each anatomical area (right and left corpus cavernosum, right and left crus). Improvement of the erectile function was evaluated using the International Index of Erectile Function (IIEF-EF), the Sexual Encounter Profile (SEP) diaries (SEP-Questions 2 and 3) and Global Assessment Questions (GAQ-Q1 and GAQ-Q2). Results: At 3-month follow-up IIEF-EF scores improved from 16.54±6.35 at baseline to 21.03±6.38. Patients answering ‘yes’ to the SEP-Q2 elevated from 61% to 89% and from 32% to 62% in the SEP-Q3. A statistically significant improvement was reported to the Global Assessment Questions (GAQ-Q1 and GAQ-Q2). Conclusion: In conclusion, we can affirm that LISW is a confirmed therapeutic approach to erectile dysfunction that definitely needs more long-term trials to be clarified and further verified. PMID:26689523

  11. Extracorporeal shockwave therapy (ESWT) ameliorates healing of tibial fracture non-union unresponsive to conventional therapy.

    PubMed

    Haffner, Nicolas; Antonic, Vlado; Smolen, Daniel; Slezak, Paul; Schaden, Wolfgang; Mittermayr, Rainer; Stojadinovic, Alexander

    2016-07-01

    Tibial non-unions are common cause of demanding revision surgeries and are associated with a significant impact on patients' quality of life and health care costs. Extracorporeal shockwave therapy (ESWT) has been shown to improve osseous healing in vitro and in vivo. The main objective of present study was to evaluate the efficacy of ESWT in healing of tibial non-unions unresponsive to previous surgical and non-surgical measures. A retrospective multivariant analysis of a prospective open, single-centre, clinical trial of tibia non-union was conducted. 56 patients with 58 eligible fractures who met the FDA criteria were included. All patients received 3000-4000 impulses of electrohydraulic shockwaves at an energy flux density of 0.4mJ/mm(2) (-6dB). On average patients underwent 1.9 times (±1.3SD) surgical interventions prior to ESWT displaying the rather negatively selected cohort and its limited therapy responsiveness. In 88.5% of patients receiving ESWT complete bone healing was observed after six months irrespective of underlying pathology. The multivariant analysis showed that time of application is important for therapy success. Patients achieving healing received ESWT earlier: mean number of days between last surgical intervention and ESWT (healed - 355.1 days±167.4SD vs. not healed - 836.7 days±383.0SD; p<0.0001). ESWT proved to be a safe, effective and non-invasive treatment modality in tibial non-unions recalcitrant to standard therapies. The procedure is well tolerated, time-saving, lacking side effects, with potential to significantly decrease health care costs. Thus, in our view, ESWT should be considered the treatment of first choice in established tibial non-unions. PMID:27158008

  12. Percolation in dense storage arrays

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, Scott; Wilcke, Winfried W.; Garner, Robert B.; Huels, Harald

    2002-11-01

    As computers and their accessories become smaller, cheaper, and faster the providers of news, retail sales, and other services we now take for granted on the Internet have met their increasing computing needs by putting more and more computers, hard disks, power supplies, and the data communications linking them to each other and to the rest of the wired world into ever smaller spaces. This has created a new and quite interesting percolation problem. It is no longer desirable to fix computers, storage or switchgear which fail in such a dense array. Attempts to repair things are all too likely to make problems worse. The alternative approach, letting units “fail in place”, be removed from service and routed around, means that a data communications environment will evolve with an underlying regular structure but a very high density of missing pieces. Some of the properties of this kind of network can be described within the existing paradigm of site or bond percolation on lattices, but other important questions have not been explored. I will discuss 3D arrays of hundreds to thousands of storage servers (something which it is quite feasible to build in the next few years), and show that bandwidth, but not percolation fraction or shortest path lengths, is the critical factor affected by the “fail in place” disorder. Redundancy strategies traditionally employed in storage systems may have to be revised. Novel approaches to routing information among the servers have been developed to minimize the impact.

  13. Fluid Mechanics.

    ERIC Educational Resources Information Center

    Drazin, Philip

    1987-01-01

    Outlines the contents of Volume II of "Principia" by Sir Isaac Newton. Reviews the contributions of subsequent scientists to the physics of fluid dynamics. Discusses the treatment of fluid mechanics in physics curricula. Highlights a few of the problems of modern research in fluid dynamics. Shows that problems still remain. (CW)

  14. Influence of shockwave profile on ejection of micron-scale material from shocked Sn surfaces: an experimental study

    SciTech Connect

    Zellner, Michael B; Byers, Mark E; Hammerberg, James E; Germann, Tim C; Dimonte, Guy; Rigg, Paulo A; Buttler, William T

    2009-01-01

    This effort experimentally investigates the relationship between shock-breakout pressure and the amount of micron-scale fragments ejected (ejecta) upon shock release at the metal/vacuum interface of Sn targets shocked with a supported shockwave. The results are compared with an analogous set derived from HE shocked Sn targets, Taylor shockwave loading. The supported shock-pulse was created by impacting a Sn target with a Ti64 (Ti-6Al-4V) impactor that was accelerated using a powder gun. Ejecta production at the free-surface or back-side of the Sn targets were characterized through use of piezoelectric pins and Asay foils, and heterodyne velocimetry verified the time of shock release and the breakout pressure.

  15. Extracorporeal shockwave lithotripsy of ureteral stone in a patient with en bloc kidney transplantation: a case report.

    PubMed

    Markic, D; Valencic, M; Grskovic, A; Spanjol, J; Sotosek, S; Fuckar, Z; Maricic, A; Pavlovic, I; Budiselic, B

    2011-06-01

    We report a case of ureterolithiasis in a patient with an en bloc kidney transplantation, using extracorporeal shockwave lithotripsy (ESWL). The patient presented with asymptomatic macrohematuria. Computed tomography revealed a ureteral calculus just below the pyeloureteral junction with hydronephrosis of the medially positioned kidney. Took two sessions of ESWL were required for complete disintegration of the stone. At 3 years after successful treatment, the patient has an excellent functioning and stone-free graft.

  16. Estimating the pressure of laser-induced plasma shockwave by stimulated Raman shift of lattice translational modes

    NASA Astrophysics Data System (ADS)

    Li, Zhanlong; Shan, Xiaoning; Li, Zuowei; Cao, Junsheng; Zhou, Mi; Wang, Yiding; Men, Zhiwei; Sun, Chenglin

    2012-07-01

    The current paper investigates stimulated Raman scattering (SRS) when laser-induced plasma is formed in heavy water by focusing an intense pulsed 532 nm Nd:YAG laser beam at room temperature. An unexpected low-frequency SRS line attributed to the lattice translational modes of ice-VII (D2O) is observed. The pressure of the plasma shockwave is estimated using low-frequency SRS line shift.

  17. Estimating the pressure of laser-induced plasma shockwave by stimulated Raman shift of lattice translational modes

    SciTech Connect

    Li Zhanlong; Shan Xiaoning; Li Zuowei; Zhou Mi; Men Zhiwei; Cao Junsheng; Wang Yiding; Sun Chenglin

    2012-07-09

    The current paper investigates stimulated Raman scattering (SRS) when laser-induced plasma is formed in heavy water by focusing an intense pulsed 532 nm Nd:YAG laser beam at room temperature. An unexpected low-frequency SRS line attributed to the lattice translational modes of ice-VII (D{sub 2}O) is observed. The pressure of the plasma shockwave is estimated using low-frequency SRS line shift.

  18. New sonic shockwave multi-element sensors mounted on a small airfoil flown on F-15B testbed aircraft

    NASA Technical Reports Server (NTRS)

    1996-01-01

    An experimental device to pinpoint the location of a shockwave that develops in an aircraft flying at transonic and supersonic speeds was recently flight-tested at NASA's Dryden Flight Research Center, Edwards, California. The shock location sensor, developed by TAO Systems, Hampton, Va., utilizes a multi-element hot-film sensor array along with a constant-voltage anemometer and special diagnostic software to pinpoint the exact location of the shockwave and its characteristics as it develops on an aircraft surface. For this experiment, the 45-element sensor was mounted on the small Dryden-designed airfoil shown in this illustration. The airfoil was attached to the Flight Test Fixture mounted underneath the fuselage of Dryden's F-15B testbed aircraft. Tests were flown at transonic speeds of Mach 0.7 to 0.9, and the device isolated the location of the shock wave to within a half-inch. Application of this technology could assist designers of future supersonic aircraft in improving the efficiency of engine air inlets by controlling the shockwave, with a related improvement in aircraft performance and fuel economy.

  19. Effectiveness of electro-acupuncture compared to sedo-analgesics in relieving pain during shockwave lithotripsy.

    PubMed

    Resim, Sefa; Gumusalan, Yakup; Ekerbicer, Hasan Cetin; Sahin, Mehmet Akif; Sahinkanat, Tayfun

    2005-08-01

    The aim of this study was to compare the clinical efficacy of electro-acupuncture (EA) with the combination of tramadol+midazolam (TM) for pain relief during outpatient extracorporeal shockwave lithotripsy (ESWL). A total of 35 patients (20 men, 15 women) with stones located in the pelvicalyceal system of the kidney were randomized prospectively to undergo lithotripsy with a third generation lithotriptor (Stone Lith, smart PCK) after receiving either EA (n=17) or TM (n=18) for sedation and analgesia. EA treatment was applied to patients by the same licensed acupuncturist 30 min prior to ESWL in group EA. Tramadol (1.5 mg/kg) 30 min before the start of lithotripsy and midazolam (0.06 mg/kg) 5 min prior to ESWL were given as a sedo-analgesic intravenously to group TM. During ESWL, blood pressure, heart rate, pain and sedation levels were measured at baseline and every 15 min thereafter. The pain intensity perceived during lithotripsy was evaluated using a visual analog scale (VAS). There was no statistical differences in the diameters of the stones and age of the patients between groups (P=0.590; P=0.568, respectively). In the EA group, the median of maximum energy level achieved was 16.0 kV (range 10-23 kV), while it was 18.0 kV (range 10-20 kV) in the TM group. There was no statistically significant difference between the maximum energy levels applied to the patients during ESWL (P=0.613). The median numbers of shockwaves were 2,114 (range 1,100-3,800) and 2,200 (range 1,500-3,200) in the EA and TM groups, respectively. In the TM group, the numbers of shockwaves used were higher than in group EA during ESWL. However, this difference was not significant (P=0.732). VAS scores were consistently lower in the EA group compared with the TM group throughout the ESWL procedure. The median VAS score was 5.0 (range 1-10) in the EA group while it was 8.0 (range 2-10) in the TM group. The patients who underwent EA had lower median scores of VAS than patients who took only

  20. Flow distortion at a dense forest edge

    NASA Astrophysics Data System (ADS)

    Dellwik, E.; Mann, J.

    2012-12-01

    Results from a forest edge experiment with two masts and one horizontally pointed wind lidar are presented. The experiment was performed at a dense beech forest edge of the Tromnæs forest, which is a 24m tall mature beech forest on the island Falster, Denmark. The topography at the site is flat. The masts were placed approximately 1.5 canopy heights upwind and downwind of the edge and are two canopy heights tall. We present data showing how the forest edge distorts the flow when the flow is perpendicular to the edge and towards the forest during near-neutral atmospheric stratification. Despite that the wind gradient above the canopy is similar before and after the edge, the momentum flux is strongly reduced above the canopy. This result is especially pronounced during summer and high leaf area index, when the momentum flux was slightly positive 1.2 canopy heights above ground level. This is contrary to the results by standard Reynolds' averaged Navier Stokes models that predict an overshoot of the momentum flux. Further above the forest, the total amount of turbulent kinetic energy remained constant compared to the upwind measurements. A reduction of the vertical variance of the flow was largely compensated by an increase in the lateral variance, whereas the streamwise variance remained approximately constant. This result is in contrast to the predictions by homogeneous rapid distortion theory. We apply and develop an alternative framework based on inhomogeneous rapid distortion theory in combination with the turbulence model by Mann (1994), which can predict the observed changes of the flow. The inhomogeneous rapid distortion theory takes the blocking of the flow by the top of the canopy into account. This effect turns out to suppress the vertical momentum flux drastically and redistribute the vertical fluctuations into the lateral direction. We show one- and two-point spectra for verification of the model. The results are relevant for understanding the on

  1. Al 1s-2p absorption spectroscopy of shock-wave heating and compression in laser-driven planar foil

    SciTech Connect

    Sawada, H.; Regan, S. P.; Radha, P. B.; Epstein, R.; Li, D.; Goncharov, V. N.; Hu, S. X.; Meyerhofer, D. D.; Delettrez, J. A.; Jaanimagi, P. A.; Smalyuk, V. A.; Boehly, T. R.; Sangster, T. C.; Yaakobi, B.; Mancini, R. C.

    2009-05-15

    Time-resolved Al 1s-2p absorption spectroscopy is used to diagnose direct-drive, shock-wave heating and compression of planar targets having nearly Fermi-degenerate plasma conditions (T{sub e}{approx}10-40 eV, {rho}{approx}3-11 g/cm{sup 3}) on the OMEGA Laser System [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. A planar plastic foil with a buried Al tracer layer was irradiated with peak intensities of 10{sup 14}-10{sup 15} W/cm{sup 2} and probed with the pseudocontinuum M-band emission from a point-source Sm backlighter in the range of 1.4-1.7 keV. The laser ablation process launches 10-70 Mbar shock waves into the CH/Al/CH target. The Al 1s-2p absorption spectra were analyzed using the atomic physic code PRISMSPECT to infer T{sub e} and {rho} in the Al layer, assuming uniform plasma conditions during shock-wave heating, and to determine when the heat front penetrated the Al layer. The drive foils were simulated with the one-dimensional hydrodynamics code LILAC using a flux-limited (f=0.06 and f=0.1) and nonlocal thermal-transport model [V. N. Goncharov et al., Phys. Plasmas 13, 012702 (2006)]. The predictions of simulated shock-wave heating and the timing of heat-front penetration are compared to the observations. The experimental results for a wide variety of laser-drive conditions and buried depths have shown that the LILAC predictions using f=0.06 and the nonlocal model accurately model the shock-wave heating and timing of the heat-front penetration while the shock is transiting the target. The observed discrepancy between the measured and simulated shock-wave heating at late times of the drive can be explained by the reduced radiative heating due to lateral heat flow in the corona.

  2. Coupled modes in magnetized dense plasma with relativistic-degenerate electrons

    SciTech Connect

    Khan, S. A.

    2012-01-15

    Low frequency electrostatic and electromagnetic waves are investigated in ultra-dense quantum magnetoplasma with relativistic-degenerate electron and non-degenerate ion fluids. The dispersion relation is derived for mobile as well as immobile ions by employing hydrodynamic equations for such plasma under the influence of electromagnetic forces and pressure gradient of relativistic-degenerate Fermi gas of electrons. The result shows the coexistence of shear Alfven and ion modes with relativistically modified dispersive properties. The relevance of results to the dense degenerate plasmas of astrophysical origin (for instance, white dwarf stars) is pointed out with brief discussion on ultra-relativistic and non-relativistic limits.

  3. Wide Variation Seen in 'Dense' Breast Diagnoses

    MedlinePlus

    ... defined mammography patients' breasts as dense. Higher breast density is a risk factor for breast cancer, experts ... could have implications for the so-called breast density notification laws that have been passed in about ...

  4. Dynamical theory of dense groups of galaxies

    NASA Technical Reports Server (NTRS)

    Mamon, Gary A.

    1990-01-01

    It is well known that galaxies associate in groups and clusters. Perhaps 40% of all galaxies are found in groups of 4 to 20 galaxies (e.g., Tully 1987). Although most groups appear to be so loose that the galaxy interactions within them ought to be insignificant, the apparently densest groups, known as compact groups appear so dense when seen in projection onto the plane of the sky that their members often overlap. These groups thus appear as dense as the cores of rich clusters. The most popular catalog of compact groups, compiled by Hickson (1982), includes isolation among its selection critera. Therefore, in comparison with the cores of rich clusters, Hickson's compact groups (HCGs) appear to be the densest isolated regions in the Universe (in galaxies per unit volume), and thus provide in principle a clean laboratory for studying the competition of very strong gravitational interactions. The $64,000 question here is then: Are compact groups really bound systems as dense as they appear? If dense groups indeed exist, then one expects that each of the dynamical processes leading to the interaction of their member galaxies should be greatly enhanced. This leads us to the questions: How stable are dense groups? How do they form? And the related question, fascinating to any theorist: What dynamical processes predominate in dense groups of galaxies? If HCGs are not bound dense systems, but instead 1D change alignments (Mamon 1986, 1987; Walke & Mamon 1989) or 3D transient cores (Rose 1979) within larger looser systems of galaxies, then the relevant question is: How frequent are chance configurations within loose groups? Here, the author answers these last four questions after comparing in some detail the methods used and the results obtained in the different studies of dense groups.

  5. Magnetic Phases in Dense Quark Matter

    SciTech Connect

    Incera, Vivian de la

    2007-10-26

    In this paper I discuss the magnetic phases of the three-flavor color superconductor. These phases can take place at different field strengths in a highly dense quark system. Given that the best natural candidates for the realization of color superconductivity are the extremely dense cores of neutron stars, which typically have very large magnetic fields, the magnetic phases here discussed could have implications for the physics of these compact objects.

  6. METHOD OF PRODUCING DENSE CONSOLIDATED METALLIC REGULUS

    DOEpatents

    Magel, T.T.

    1959-08-11

    A methcd is presented for reducing dense metal compositions while simultaneously separating impurities from the reduced dense metal and casting the reduced parified dense metal, such as uranium, into well consolidated metal ingots. The reduction is accomplished by heating the dense metallic salt in the presence of a reducing agent, such as an alkali metal or alkaline earth metal in a bomb type reacting chamber, while applying centrifugal force on the reacting materials. Separation of the metal from the impurities is accomplished essentially by the incorporation of a constricted passageway at the vertex of a conical reacting chamber which is in direct communication with a collecting chamber. When a centrifugal force is applled to the molten metal and slag from the reduction in a direction collinear with the axis of the constricted passage, the dense molten metal is forced therethrough while the less dense slag is retained within the reaction chamber, resulting in a simultaneous separation of the reduced molten metal from the slag and a compacting of the reduced metal in a homogeneous mass.

  7. Management of common bile duct stones using a second-generation extracorporeal shockwave lithotriptor.

    PubMed

    Nicholson, D A; Martin, D F; Tweedle, D E; Rao, P N

    1992-08-01

    Fifty-four patients with common bile duct stones (8-36 mm in diameter) that could not be removed after endoscopic sphincterotomy, even with the use of mechanical lithotripsy, underwent extracorporeal shockwave lithotripsy (ESWL) using a Siemens Lithostar. Their median age was 75.5 (range 34-89) years. Patients received 4000-6000 shocks per session over approximately 60 min. Seventeen underwent two sessions and two patients three or more. Thirty-seven patients had one stone, ten had two, and seven had three or more. Spontaneous clearance of fragments occurred in only three patients before further endoscopic retrograde cholangiopancreatography was performed to remove fragments. Stones were removed and ducts cleared endoscopically in 35 patients, giving a total of 38 of 54 patients (70 per cent) with complete duct clearance. Fragmentation in response to lithotripsy was dependent on stone size; the number of stones had little effect. ESWL was well tolerated without any haematological or biochemical abnormality. Computed tomography in the first 20 patients showed no hepatic or pancreatic change after treatment. ESWL combined with endoscopic extraction of fragments is an alternative to surgery when preliminary endoscopic extraction and mechanical lithotripsy have failed.

  8. Effectiveness of extracorporeal shockwave lithotripsy in the management of stone-bearing horseshoe kidneys.

    PubMed

    Kirkali, Z; Esen, A A; Mungan, M U

    1996-02-01

    Although extracorporeal shockwave lithotripsy (SWL) has dramatically changed the management of urinary tract stone disease, the anatomic abnormalities of horseshoe kidneys cause some difficulties in the use of SWL in this disorder. In this study, 18 patients with stone-bearing horseshoe kidneys were investigated retrospectively in order to determine the effectiveness of SWL. Patients received an average of 11,437 + or - 3062 shocks at an average of 18.8 kV with the Siemens Lithostar. Ten patients were treated in the supine position; stones could be localized in the prone position in eight. Catheterization with a double-J stent was the only adjunctive procedure; it was used in four patients prior to SWL. Adequate stone fragmentation (smaller than 5 mm) was achieved in 14 of the 18 patients (78%). Although 5 of them (28%) became stone free within 6 months after the treatment, residual fragments persisted in 9 patients (50%) during the mean follow-up of 55 months. Stones of 4 patients (22%) were not fragmented adequately. We concluded that although adequate fragmentation can be achieved in stone-bearing horseshoe kidneys, the anatomic abnormalities prevent fragment passage in a substantial number of patients.

  9. Extracorporeal Shockwave Lithotripsy Monotherapy is not Adequate for Management of Staghorn Renal Calculi.

    PubMed

    Koko, Abdelmoniem K; Onuora, Vincent C; Al Turki, Mohammed A; Mesbed, Ahmed H; Al Jawini, Nasser A

    2003-01-01

    Between 1990 and 1999 a total of 186 patients with staghorn renal stones were treated in our unit. Of them, 76 patients were managed by extra-corporeal shockwave lithotripsy (ESWL) alone using a third generation Siemen's Lithostar Plus lithotriptor. Sixty-one of these patients who completed a follow-up of 41 months formed the subjects of this study. ESWL was done after routine stenting of the affected side in all cases except one. The mean number of ESWL sessions was 5.2, delivering an average 15,940 shocks per patient. The average hospital stay was 21.68 days and the duration of the treatment was 1-41 months (mean 6.75 months). Significant complications occurred in 35 patients (57.4%) eight of whom sustained multiple significant complications. A total of 162 auxiliary procedures were used in conjunction with ESWL and in the management of complications. The stone free rate at three months was 18%, but rose by the end of the treatment period (41 months) to 63.9%. Our study indicates that ESWL monotherapy is associated with high morbidity rates, high rates of unplanned invasive procedures as well as prolonged treatment periods and hospitalization. Thus, ESWL monotherapy is not adequate for the management of staghorn calculi.

  10. Effect of extracorporeal shockwave treatment on the melanogenic activity of cultured melanocytes.

    PubMed

    Huang, Faye; Kuo, Hsi-Kung; Hsieh, Ching-Hua; Wu, Pei-Chang; Wu, Yi-Chan; Wang, Ching-Jen

    2012-02-01

    In addition to the traditional lithotripsy treatment, extracorporeal shockwaves (ESWs) have been shown to be effective in the treatment of certain musculoskeletal disorders and in enhancing skin flap neovascularization. However, relatively little is known about its effect on melanocytes. To investigate its effect on the melanogenic activity of cultured melanocytes, mouse B16F10 melanocytes were treated with defocused ESWs of different energies (15, 21, and 27 kV) and at different doses (300 and 600 impulses). Cell viability was measured 1 and 24 h after treatment. Melanin content was measured and compared against a standard curve generated with fungal melanin. Cellular tyrosinase activity was calculated with the 3,4-dihydroxyphenylalanine (DOPA) oxidase assay. The results demonstrated that ESW treatment reduced cell viability. Our results also indicated that the overall decrease in cell viability lasted for 6 days. After ESW treatment with 300 or 600 impulses at 21 kV, no significant change in melanin content or tyrosinase activity of the B16F10 melanocytes was noted as compared to those of the control. The present study suggests that ESW treatment does not alter the melanogenic activity of the cultured melanocytes.

  11. Comparison of hydrodynamic simulations with two-shockwave drive target experiments

    NASA Astrophysics Data System (ADS)

    Karkhanis, Varad; Ramaprabhu, Praveen; Buttler, William

    2015-11-01

    We consider hydrodynamic continuum simulations to mimic ejecta generation in two-shockwave target experiments, where metallic surface is loaded by two successive shock waves. Time of second shock in simulations is determined to match experimental amplitudes at the arrival of the second shock. The negative Atwood number (A --> - 1) of ejecta simulations leads to two successive phase inversions of the interface corresponding to the passage of the shocks from heavy to light media in each instance. Metallic phase of ejecta (solid/liquid) depends on shock loading pressure in the experiment, and we find that hydrodynamic simulations quantify the liquid phase ejecta physics with a fair degree of accuracy, where RM instability is not suppressed by the strength effect. In particular, we find that our results of free surface velocity, maximum ejecta velocity, and maximum ejecta areal density are in excellent agreement with their experimental counterparts, as well as ejecta models. We also comment on the parametric space for hydrodynamic simulations in which they can be used to compare with the target experiments.

  12. Prostaglandin E2 and Connexin 43 crosstalk in the osteogenesis induced by extracorporeal shockwave.

    PubMed

    Chen, Youbin; Xu, Jiankun; Liao, Haojie; Ma, Zebin; Zhang, Yuantao; Chen, Hongjiang; Huang, Zhonglian; Hu, Jun

    2016-09-01

    As a type of mechanical stimulation, extracorporeal shockwave (ESW) has been widely used in the clinic to treat bone fracture delayed union and non-unions. A large number of studies have shown beneficial effects of ESW in promoting fracture healing by inducing bone regeneration; however, the underlying mechanisms remain unclear. ESW has been shown to induce the production of prostaglandin E2 (PGE2), which is essential for gap junction intercellular communication in response to mechanical stress. Among the 19 known gap junction subunits, connexin43 (Cx43) is the most prevalent for mediating the response of mechanical stress. However, to our knowledge, the effect of ESW on Cx43 expression has not been reported before. Herein, we propose that a crosstalk between PGE2 and Cx43 is involved in the enhancement of osteogenesis induced by ESW. We review the currently available data to propose an unrevealed, but important mechanism via which ESW treatment affects osteogenic differentiation of bone marrow stromal cells.

  13. High-energy shockwaves and extracorporeal high-intensity focused ultrasound.

    PubMed

    Madersbacher, Stephan; Marberger, Michael

    2003-10-01

    We review the physical interactions of focused ultrasound with tissue, describe technical features of current high-energy shockwave (HESW) and extracorporeal high-intensity focused ultrasound (HIFU) devices, and summarize the experimental and human data available to date. Tissue destruction by extracorporeal HIFU is not new: the first clinical attempts were made almost half a century ago for ablating brain tissue. Despite recent progress in the knowledge of the interactions between HIFU and tissue and significant device modifications, this technique is still in its infancy. The most promising targets for this kind of therapy in the field of urology are the kidney, bladder, and testis. The largest clinical experience with HIFU therapy currently available is for benign prostatic enlargement and prostate cancer using transrectal HIFU devices, which are not the topic of this summary. In parallel with HIFU, HESW therapy has been tested in numerous experimental and preclinical settings. This technique is currently not in routine clinical use. Theoretically, in parallel with HIFU, any organ accessible to conventional diagnostic ultrasound examination is a potential target for this kind of therapy.

  14. Biliary extracorporeal shockwave lithotripsy: short-term and long-term observations in an animal model.

    PubMed

    Vergunst, H; Terpstra, O T; Brakel, K; Nijs, H G; Laméris, J S; ten Kate, F J; Schröder, F H

    1993-08-01

    The short- and long-term effects of biliary extracorporeal shockwave lithotripsy (ESWL) using an electromagnetic lithotriptor were investigated in 26 pigs. After implantation of single human gallstones into their gallbladders, all but 4 control pigs were subjected to 4,000 or 8,000 shock waves and killed one day (n = 9), one week (n = 7), or one year (n = 6) thereafter. Post-ESWL, no abnormalities of chest radiographs or laboratory tests were detected. Apart from focal injury of the gallbladder and liver, in 4 out of 9 pigs subpleural pulmonary hemorrhages were found one day post-ESWL. However, tissue damage was largely reversed within one week and after one year only small hepatic scars persisted as permanent damage. Stone fragmentation occurred in 19 (86%) out of 22 pigs, and was adequate (fragments < or = 5 mm) in 9 (41%) pigs. Tissue damage and stone fragmentation after 4,000 as compared with 8,000 shock waves were not significantly different. These data warrant further evaluation of this lithotriptor in human studies.

  15. Extracorporeal shockwave enhanced regeneration of fibrocartilage in a delayed tendon-bone insertion repair model.

    PubMed

    Chow, Dick Ho Kiu; Suen, Pui Kit; Huang, Le; Cheung, Wing-Hoi; Leung, Kwok-Sui; Ng, Chun; Shi, San Qiang; Wong, Margaret Wan Nar; Qin, Ling

    2014-04-01

    Fibrous tissue is often formed in delayed healing of tendon bone insertion (TBI) instead of fibrocartilage. Extracorporeal shockwave (ESW) provides mechanical cues and upregulates expression of fibrocartilage-related makers and cytokines. We hypothesized that ESW would accelerate fibrocartilage regeneration at the healing interface in a delayed TBI healing model. Partial patellectomy with shielding at the TBI interface was performed on 32 female New Zealand White Rabbits for establishing this delayed TBI healing model. The rabbits were separated into the control and ESW group for evaluations at postoperative week 8 and 12. Shielding was removed at week 4 and a single ESW treatment was applied at week 6. Fibrocartilage regeneration was evaluated histomorphologically and immunohistochemically. Vickers hardness of the TBI matrix was measured by micro-indentation. ESW group showed higher fibrocartilage area, thickness, and proteoglycan deposition than the control in week 8 and 12. ESW increased expression of SOX9 and collagen II significantly in week 8 and 12, respectively. ESW group showed a gradual transition of hardness from bone to fibrocartilage to tendon, and had a higher Vickers hardness than the control group at week 12. In conclusion, ESW enhanced fibrocartilage regeneration at the healing interface in a delayed TBI healing model.

  16. Shockwave-induced plasticity via large-scale nonequilibrium molecular dynamics

    SciTech Connect

    Holian, B.L.

    1998-07-01

    Nonequilibrium molecular-dynamics (MD) simulations of shock waves in single crystals have shown that, above a threshold strength, strongly shocked crystals deform in a very simple way. Rather than experiencing massive deformation, a simple slippage occurs at the shock front, relieving the peak shear stress, and leaving behind a stacking fault. Later calculations quantified the apparent threshold strength, namely the yield strength of the perfect crystal. Subsequently, pulsed x-ray experiments on shocked single crystals showed relative shifts in diffraction peaks, confirming our MD observations of stacking faults produced by shockwave passage. With the advent of massively parallel computers, we have been able to simulate shock waves in 10-million atom crystals with cross-sectional dimensions of 100{times}100 fcc unit cells (compared to earlier 6{times}6 systems). We have seen that the increased cross-section allows the system to slip along all of the available {l_brace}111{r_brace} slip planes, in different places along the now non-planar shock front. These simulations conclusively eliminate the worry that the kind of slippage we have observed is somehow an artifact of transverse periodic boundary conditions. Thus, future simulations are much more likely to show that weak-shock plasticity is nucleated by pre-existing extended defects embedded in the sample. {copyright} {ital 1998 American Institute of Physics.}

  17. [Diverticular calculi of the kidney calices--extracorporeal shockwave lithotripsy, percutaneous extraction or open surgery].

    PubMed

    Kriegmair, M; Schüller, J; Schmeller, N; Knipper, A; Muschter, R; Hofstetter, A G

    1990-07-01

    The incidence of caliceal diverticula, mostly found on routine excretory urography, is very low. The indications for treatment include chronic or recurrent pyelonephritis, pain, gross hematuria and renal damage. There is controversy as to which treatment is best: extracorporeal shock-wave lithotripsy (ESWL), percutaneous techniques, or traditional open surgery. Since 1984, 27 patients with 28 caliceal diverticula calculi have been treated. Ten patients underwent ESWL, 13 patients percutaneous treatment, and 4 patients open surgery. The success rates as far as a stone-free status is concerned were: 1 patient (ESWL), 10 (percutaneous), and 4 (open surgery). There were no complications due to ESWL or open surgical treatment. Direct traumata such as severe bleeding in two and hydrothorax in one patient occurred during the training phase of the percutaneous techniques. Due to the low complication rate, non-invasive ESWL treatment should be tried first. The indications for percutaneous removal of calculi in caliceal diverticula depend on two aspects: it should be possible to puncture the caliceal diverticula via by a short parenchymal route coaxial to the axis of the calix and, if the intercostal approach is used, a pleural lesion must be excluded. If these requirements cannot be fulfilled, open surgical treatment should be performed, especially if the diverticula are located in the upper and anterior part of the kidney.

  18. [Extrasystoles during extracorporeal biliary shockwave lithotripsy. Their incidence and clinical significance].

    PubMed

    Rambow, A; Staritz, M; Grosse, A; Treese, N; Mayer, K; Meyer zum Büschenfelde, K H

    1991-02-15

    Incidence and clinical significance of cardiac side effects of extracorporeal shock-wave lithotripsy (ESWL) were prospectively analysed for 85 patients (26 men, 59 women; mean age 44 [17-81] years) with cholecystolithiasis (n = 70) or choledocholithiasis (n = 15). 24-hour ECG monitoring was undertaken on the day of treatment. Additionally, during ESWL cardiac rhythm and blood pressure were monitored. ESWL was performed with an electromagnetic lithotriptor under light anaesthesia with intravenous diazepam (10 mg) and pethidine (75-100 mg). There were no superventricular premature systoles in any of the patients during treatment. In 15 patients with occasional ventricular premature systoles (VPS) (6-81 per 23 hours) in the 24-hour ECG the number of VPS increased during the one-hour ESWL procedure significantly to 6-55 (P less than 0.05). 14 of these patients had an unremarkable cardiac history. Changing the lithotriptor coupling angle failed to suppress the VPS in only two patients. In these two it was necessary to trigger the shock wave with the ECG. Blood pressure rose markedly (up to 220 mm Hg systolic) during ESWL in only three patients, known hypertensives. But this rise was easily controlled with nifedipine, 10 mg sublingually. These data demonstrate that ESWL is a safe alternative to operative treatment, even in the presence of existing cardiac disease. Nonetheless, precautions should be taken in case there are complications.

  19. Osteogenesis induced by extracorporeal shockwave in treatment of delayed osteotendinous junction healing.

    PubMed

    Qin, Ling; Wang, Lin; Wong, Margaret Wan-nar; Wen, Chunyi; Wang, Gang; Zhang, Ge; Chan, Kai-ming; Cheung, Wing-hoi; Leung, Kwok-sui

    2010-01-01

    Healing at the osteotendinous junction (OTJ) is challenging in orthopedic surgery. The present study aimed to test extracorporeal shockwave (ESW) in treatment of a delayed OTJ healing. Twenty-eight rabbits were used for establishing a delayed healing (DH) model at patella-patellar-tendon (PPT) complex after partial patellectomy for 4 weeks and then were divided into DH and ESW groups. In the ESW group, a single ESW treatment was given at postoperative week 6 to the PPT healing complex. The samples were harvested at week 8 and 12 for radiographic and histological evaluations with seven samples for each group at each time point. Micro-CT results showed that new bone volume was 1.18 +/- 0.61 mm(3) in the ESW group with no measurable new bone in the DH group at postoperative week 8. Scar tissue formed at the OTJ healing interface of the DH group, whereas ESW triggered high expression of VEGF in hypertrophic chondrocytes at week 8 and regeneration of the fibrocartilage zone at week 12 postoperatively. The accelerated osteogenesis could be explained by acceleration of endochondral ossification. In conclusion, ESW was able to induce osteogenesis at OTJ with delayed healing with enhanced endochondral ossification process and regeneration of fibrocartilage zone. These findings formed a scientific basis to potential clinical application of ESW for treatment of delayed OTJ healing.

  20. Chronic kidney disease in urolithiasis patients following successful extracorporeal shockwave lithotripsy.

    PubMed

    Maeda, Satoshi; Naganuma, Toshihide; Takemoto, Yoshiaki; Shoji, Tetsuo; Okamura, Mikio; Nakatani, Tatsuya

    2012-01-01

    Recently, it has been reported that kidney stones are a significant and independent risk factor for chronic kidney disease (CKD) in the general population. However, the prevalence of CKD in patients following successful extracorporeal shockwave lithotripsy (ESWL) has yet to be elucidated. In the present study, the prevalence of CKD and the clinical factors associated with the presence of CKD in patients following successful ESWL were investigated. A cross‑sectional study was performed in 114 patients who had undergone ESWL for upper urinary tract stones and 96 age- and gender-matched healthy control subjects. We initially determined the stage of CKD and compared the prevalence of CKD between healthy subjects and patients who underwent successful ESWL. We then investigated the clinical factors associated with the presence of CKD by logistic regression analysis. The prevalence of CKD was significantly higher in patients following successful ESWL than in the healthy subjects [40 patients (35.1%) vs. 9 healthy controls (9.4%), P<0.0001]. Logistic regression analysis showed that the significant factors associated with the presence of CKD were increased body mass index (BMI) and the presence of a ureteric stone (pre‑ESWL stone position). The findings indicated that there was a high prevalence of CKD among patients following successful ESWL, and that an increased BMI and a ureteric stone were factors associated with the presence of CKD.

  1. Induced gall-bladder contraction accelerates fragment clearance after extracorporeal shockwave lithotripsy.

    PubMed

    Ziegenhagen, D J; Zehnter, E; Kruis, W; Pohl, C

    1993-01-01

    At the end of extracorporeal shockwave lithotripsy (ESWL) gallstone fragments are dispersed throughout the gall-bladder. In this state they should be expelled more easily than when later sedimented to the gall-bladder fundus. Thus, a randomized study was performed to evaluate the clinical benefit of induced gall-bladder contraction after ESWL. One hundred and five patients with radiolucent gallstones (1-3 stones, diameter < or = 30 mm) were randomized to received either saline or an infusion of 0.2 micrograms/kg ceruletide. Stone clearance rates and incidence of biliary symptoms were recorded. Clearance rates at 6 weeks and 3 months after ESWL were significantly (P < 0.025) improved by the ceruletide infusion. This effect, resulting in shortened bile acid therapy, was limited to patients with small solitary stones and dependent on a good initial fragmentation. Major side effects attributable to ceruletide were not observed. These results suggest that induced gall-bladder contraction can be successfully applied as an adjuvant treatment in a subgroup of patients with small solitary gallstones.

  2. How painful are shockwave lithotripsy and endoscopic procedures performed at outpatient urology clinics?

    PubMed

    Jeong, Byong Chang; Park, Hyoung Keun; Kwak, Cheol; Oh, Seong-June; Kim, Hyeon Hoe

    2005-08-01

    Our aim was to investigate the subjective pain felt by patients during shockwave lithotripsy (SWL) and endoscopic procedures such as cystoscopy, retrograde ureteral stenting, retrograde pyelography (RGP), and ureteroscopic lithotripsy performed in an outpatient clinic, and to identify how severe pain during such procedures is. We estimated subjective pain in 984 patients after SWL (186), cystoscopy (489), retrograde ureteral stenting (127), RGP (97), and ureteroscopic lithotripsy (85) performed by a single expert in an outpatient clinic using a prospective questionnaire with a ten point visual analog scale between January 2001 and December 2003. There was no premedication in any procedure except ureteroscopic lithotripsy for which an intramuscular injection of analgesics (pethidine HCl 50 mg) was used. The pain scale score in SWL was 6.62+/-2.27, the highest among the procedures (P<0.05). Pain scores for endoscopies were 4.48+/-2.07 in retrograde ureteral stenting, 3.81+/-2.06 in ureteroscopic lithotripsy, 3.72+/-1.75 in RGP, and 3.08+/-1.95 in cystoscopy. In this study, we observed that patients feel most pain in SWL without anesthesia, and that pain during ureteroscopic lithotripsy under local anesthesia is not high, compared with other endoscopic procedures.

  3. Anesthesia for extracorporeal shockwave lithotripsy: Teikyo University Hospital experience using the third generation lithotripter.

    PubMed

    Kurihara, Koji; Kamiyama, Yutaka; Saito, Keisuke; Yasuda, Mitsuko; Ide, Hisamitsu; Muto, Satoru; Okada, Hiroshi; Horie, Shigeo

    2007-08-01

    A single-board certified urologist with training and experience in anesthesiology was assigned to treat 502 patients (185 with renal stones, 317 with ureteral stones) using the Dornier Compact Delta lithotripter under general or epidural anesthesia. Data were obtained regarding stone location, stone size, shockwave use, stone-free rate, and complications. In all, 502 stones were treated with the Dornier Compact Delta lithotripter. Among renal stones, 73% were in the renal pelvis. Among ureteral stones, 60% were in the upper, 10% in the middle, and 30% in the lower ureter. Diameters of 61.8% of stones were less than 1 cm. The mean number of shocks was 3,471 at a mean power setting of 5. The stone-free rate for renal stones was 71.5%, while for ureteral stones this reached 99%. The efficiency quotient was calculated as 0.65. One patient with a renal stone developed perinephric hematoma requiring 3 units of transfusion. With a success rate higher than that reported for other lithotripters, the Dornier Compact Delta lithotripter represents a feasible treatment for urolithiasis. We stress that even in the third generation machines the lithotripsy under anesthesia can improve the treatment efficacy.

  4. Spectroscopic diagnostics of plume rebound and shockwave dynamics of confined aluminum laser plasma plumes

    SciTech Connect

    Yeates, P.; Kennedy, E. T.

    2011-06-15

    Generation and expansion dynamics of aluminum laser plasma plumes generated between parallel plates of varying separation ({Delta}Z = 2.0, 3.2, 4.0, and 5.6 mm), which confined plume expansion normal to the ablation surface, were diagnosed. Space and time resolved visible emission spectroscopy in the spectral range {lambda} = 355-470 nm and time gated visible imaging were employed to record emission spectra and plume dynamics. Space and time resolved profiles of N{sub e} (the electron density), T{sub e} (the electron temperature), and T{sub ionz} (the ionization temperature) were compared for different positions in the plasma plume. Significant modifications of the profiles of the above parameters were observed for plasma-surface collisions at the inner surface of the front plate, which formed a barrier to the free expansion of the plasma plume generated by the laser light on the surface of the back plate. Shockwave generation at the collision interface resulted in delayed compression of the low-density plasma plume near the inner ablation surface, at late stages in the plasma history. Upon exiting the cavity formed by the two plates, through an aperture in the front plate, the plasma plume underwent a second phase of free expansion.

  5. [Endoscopy, shockwave lithotripsy and local lysis in complicated pigmentary calculi of extra- and intrahepatic bile ducts].

    PubMed

    Güldütuna, S; Hellstern, A; Leuschner, M; Kurtz, W; Lembcke, B; Heller, K; Leuschner, U

    1991-02-22

    Endoscopy, extracorporeal shockwave lithotripsy (ESWL) and local lysis with alkaline solution of EDTA and bile salts in water were applied in combination in four patients with extra- and intrahepatic pigment stones as well as calcium bilirubinate covered concrements of the biliary tract. In the first patient (a man aged 80 years) a giant concrement of the bile duct was broken up after ESWL by three weeks of local chemical lysis and the fragments were removed by endoscopy. In the second case (man, aged 72), a nonextractable pigment stone was at first reduced in size by four-day local lysis and then removed endoscopically. Intrahepatic pigment stones were completely removed in the other two patients (boy of 12, man of 62) by local lysis only in 3 and 15 weeks, respectively. Even long-term use of the alkaline solution may not cause any serious side effects. Breaking up of stones after size reduction with ESWL of giant stones, size reduction of intact stones and contact lysis of intrahepatic stones are three important indications for chemical dissolution of biliary tract stones, respectively.

  6. Minor residual fragments after extracorporeal shockwave lithotripsy: spontaneous clearance or risk factor for recurrent stone formation?

    PubMed

    Buchholz, N P; Meier-Padel, S; Rutishauser, G

    1997-08-01

    The aim of this study was to follow the fate of residual stone fragments (RF) < 5 mm after extracorporeal shockwave lithotripsy (SWL) over a sufficiently long period to determine how many are spontaneously cleared and after what time interval. A further aim was to clarify their role in clinical outcome and stone recurrence and regrowth. The clinical and radiologic data of 266 patients were analyzed. The patients were followed up for a mean of 387 days. After SWL, 55 patients (21%) had residual fragments < 5 mm in diameter. There were no significant differences between the stone-free patients and those with RF with regard to age, sex, relevant medical history, or SWL treatment. After a mean follow-up of 2.5 years, 12.7% of the residual fragments had not passed spontaneously, but all of them were clinically silent and located exclusively in the lower calices and the proximal ureter. Only 2% of the patients with RF showed stone regrowth, and no stone recurrences were observed within the follow-up period. In conclusion, although a minor pathophysiological role of RF < or = 5 mm cannot be discounted in recurrence and regrowth of kidney stones after SWL, more invasive attempts to clear all minor fragments do not seem warranted.

  7. Selective loss of unmyelinated nerve fibers after extracorporeal shockwave application to the musculoskeletal system.

    PubMed

    Hausdorf, J; Lemmens, M A M; Heck, K D W; Grolms, N; Korr, H; Kertschanska, S; Steinbusch, H W M; Schmitz, C; Maier, M

    2008-07-31

    Application of extracorporeal shockwaves (ESW) to the musculoskeletal system may induce long-term analgesia in the treatment of chronic tendinopathies of the shoulder, heel and elbow. However, the molecular and cellular mechanisms behind this phenomenon are largely unknown. Here we tested the hypothesis that long-term analgesia caused by ESW is due to selective loss of nerve fibers in peripheral nerves. To test this hypothesis in vivo, high-energy ESW were applied to the ventral side of the right distal femur of rabbits. After 6 weeks, the femoral and sciatic nerves were investigated at the light and electron microscopic level. Application of ESW resulted in a selective, substantial loss of unmyelinated nerve fibers within the femoral nerve of the treated hind limb, whereas the sciatic nerve of the treated hind limb remained unaffected. These data might indicate that alleviation of chronic pain by selective partial denervation may play an important role in the effects of clinical ESW application to the musculoskeletal system.

  8. Comparison of hydrodynamic simulations with two-shockwave drive target experiments

    NASA Astrophysics Data System (ADS)

    Karkhanis, Varad; Ramaprabhu, Praveen; Buttler, William

    2015-11-01

    We consider hydrodynamic continuum simulations to mimic ejecta generation in two-shockwave target experiments, where metallic surface is loaded by two successive shock waves. Time of second shock in simulations is determined to match experimental amplitudes at the arrival of the second shock. The negative Atwood number A --> - 1 of ejecta simulations leads to two successive phase inversions of the interface corresponding to the passage of the shocks from heavy to light media in each instance. Metallic phase of ejecta (solid/liquid) depends on shock loading pressure in the experiment, and we find that hydrodynamic simulations quantify the liquid phase ejecta physics with a fair degree of accuracy, where RM instability is not suppressed by the strength effect. In particular, we find that our results of free surface velocity, maximum ejecta velocity, and maximum ejecta areal density are in excellent agreement with their experimental counterparts, as well as ejecta models. We also comment on the parametric space for hydrodynamic simulations in which they can be used to compare with the target experiments. This work was supported in part by the (U.S.) Department of Energy (DOE) under Contract No. DE-AC52-06NA2-5396.

  9. Is percutaneous monotherapy for staghorn calculus still indicated in the era of extracorporeal shockwave lithotripsy?

    PubMed

    Rodrigues Netto, N; Claro, J de A; Ferreira, U

    1994-06-01

    Staghorn stones can be treated by percutaneous nephrolithotomy (PCNL) or by extracorporeal shockwave lithotripsy (SWL); however, the combination of the two techniques appears as the most frequent treatment. In a previous study, the investigators noted that staghorn calculi treated with PCNL monotherapy have a good clearance rate. Herein, we have reviewed 102 staghorn stones that underwent PCNL before (1984-1986) (Group 1; n = 51) and after (1987-1990) (Group 2; n = 45) the introduction of SWL. The stone burden has increased in both size and complexity: there were 27 complete staghorn calculi (60%) in Group 2 compared with 19 (37%) in Group 1. Despite the higher number of kidney punctures, blood urea nitrogen and serum creatinine measurements demonstrated improvement of renal function postoperatively. The stone-free rates were 78% and 89% and the retreatment rates 31% and 18% in Groups 1 and 2, respectively. Complications (29% and 38%) were a function of the technical factors that become more apparent in the more difficult cases. Our data support the concept that the surgeon should have no previous intention to use the lithotripter and, therefore, should try to remove the entire stone percutaneously safely and economically.

  10. Effects of radial shockwave therapy on the limb function of dogs with hip osteoarthritis.

    PubMed

    Mueller, M; Bockstahler, B; Skalicky, M; Mlacnik, E; Lorinson, D

    2007-06-01

    The objective of this study was to evaluate the effects of extracorporeal radial shock wave therapy on the hindlimb function of dogs suffering from hip osteoarthritis. Twenty-four client-owned dogs with hip osteoarthritis were investigated; 18 of them received radial shockwave therapy and six were left untreated as controls. Force plate analysis on a treadmill was used to assess the dogs' hindlimb function before treatment and four weeks after the last treatment, and the treated dogs were re-evaluated three and six months after the treatment. The parameters chosen for evaluation were peak vertical force and vertical impulse, and the calculated symmetry indices. In the treated dogs, differences between the ground reaction forces exerted by the right and left hindlegs disappeared four weeks after the treatment, whereas in the control dogs only the peak vertical force distribution changed significantly. The significant improvement in the treated dogs was confirmed by changes in the symmetry indices. Significant improvements in vertical impulse and peak vertical force were observed three months after the treatment.

  11. Extracorporeal shock-wave therapy for chronic lateral tennis elbow--prediction of outcome by imaging.

    PubMed

    Maier, M; Steinborn, M; Schmitz, C; Stäbler, A; Köhler, S; Veihelmann, A; Pfahler, M; Refior, H J

    2001-07-01

    Today the clinical use of extracorporeal shockwave application (ESWA) for the treatment of lateral tennis elbow is hampered by the lack of results from randomized controlled trials and of predictive parameters of clinical outcome. The present prospective study aimed to provide the latter by means of magnetic resonance imaging (MRI). Twenty-three female and 19 male patients with unilateral chronic tennis elbow of the dominant site were clinically examined before and after repetitive low-energy ESWA. MRI was performed before ESWA to evaluate signal intensity changes or contrast enhancement of the common extensor tendon and the lateral epicondyle. After ESWA (mean follow-up period 18.6 months for all patients), clinical evaluation showed a significantly better mean clinical performance after ESWA than before treatment. Interestingly, male patients showed a significantly better mean clinical performance after ESWA than female patients, and male and female patients differed significantly in the signal intensity of the common extension tendon cross-section and tendon thickening on MRI. For female patients, MRI scans could be applied for predicting a positive clinical outcome of ESWA. This study reports the first indication of predictability of positive clinical outcome of the treatment of chronic lateral tennis elbow by ESWA using imaging prior to treatment. This may serve as an important step towards overcoming the therapeutic nihilism with respect to the non-operative management of this condition recently in the literature.

  12. Do renal cysts affect the success of extracorporeal shockwave lithotripsy? A retrospective comparative study.

    PubMed

    Gücük, Adnan; Oztürk, Ufuk; Uyetürk, Uğur; Kemahlı, Eray; Akın, Güven; Imamoğlu, M Abdurrahim; Metin, Ahmet

    2013-01-01

    The aim of this study was to assess the effect of simple renal cysts on extracorporeal shockwave lithotripsy (SWL) in patients with calyceal renal calculi. Patients with simple renal cysts >35 mm and ipsilateral renal calculi <20 mm that were treated with SWL constituted group 1 (cyst + calculi). The control group included patients aged >40 years that had renal calculi <20 mm and no cysts that were treated with SWL. The 2 groups were compared according to age, gender, body mass index, calculi size, localization, and density, the calculi fragmentation rate, and the percentage of stone-free patients. Mean cyst size in group 1 was 44.04 ± 9.08 mm. Mean age in group 1 was 61.4 ± 10.2 years versus 56.9 ± 8.2 years in the control group; the difference was significant (P = 0.045). There were not any other significant differences between the 2 groups, except for the stone-free rate (P > 0.05), which was 33.3% in group 1 and 68.2% in the control group (P = 0.017). The presence of renal cysts in a patient with calculi requires that an individualized treatment plan be devised, so as to provide the patient with the most effective treatment.

  13. [Low energy extracorporeal shockwave therapy (ESWT) for treatment of myogelosis of the masseter muscle].

    PubMed

    Kraus, M; Reinhart, E; Krause, H; Reuther, J

    1999-01-01

    Patients with functional disorders of the temporomandibular apparatus often show painful myogelosis, especially of the masseter muscle. The cause is hypertonia of the affected muscle. The aim of the presented single-blinded clinical trial was to analyze the effects of low-energy extracorporeal shock waves on patients with pain sensitivity in this region. Participating in the trial were 50 patients with painful, palpable and sonographically evident myogelosis of the masseter muscle. Half of the patients received a single application of 250 impulses of 0.04 mJ/mm2. The second half received an equivalent placebo treatment with the shock-wave impact being inhibited by a neopren insert. It was shown that in 64% of the patients significant alleviation of pain with palpable and sonographically evident softening of the myogelosis could be achieved. In 40% of the patients the therapeutic result could be conserved over a period of 2 weeks. The difference from the placebo group was statistically highly significant. ESWT is thus an easy-to-use, non-invasive method of initial pain therapy for patients with functional disorders. To preserve the long-term therapeutic result, additional functional therapy is nevertheless necessary.

  14. Piezoelectric extracorporeal shockwave lithotripsy for bile duct stone formation after choledochal cyst excision.

    PubMed

    Okada, Yasuhiro; Miyamoto, Masatoshi; Yamazaki, Toru; Motoi, Isamu; Kuribayashi, Masato; Kodama, Koichi

    2007-04-01

    We report a case of bile duct stones in which piezoelectric extracorporeal shockwave lithotripsy (ESWL) was highly effective for the clearance of stones. A 16-year-old girl, who had undergone excision of a choledochal cyst when she was 3 years old, presented a spiking fever and colic abdominal pain. Radiological investigations showed two large stones incarcerating to the proximal end of hepatico-jejunostomy anastomosis. Massive debris was also present in intrahepatic bile duct proximal to the anastomosis. She underwent piezoelectric ESWL with an EDAP LT02 lithotripter. An average of 40 min ESWL session was repeated at intervals of 2 or 3 days. Neither anesthetic nor sedative treatment was required. By the end of the sixth session, the stones incarcerated were fragmented and the debris in the intrahepatic bile duct was completely eliminated. We conclude that piezoelectric ESWL is a less invasive, effective and repeatable method, therefore, it could be a treatment of choice for bile duct stone formation after choledochal cyst excision.

  15. Impact of ureteric stent on outcome of extracorporeal shockwave lithotripsy: A propensity score analysis

    PubMed Central

    Gołąb, Adam; Słojewski, Marcin

    2016-01-01

    Introduction Extracorporeal shockwave lithotripsy (SWL) is one of the most frequently performed procedures in patients with urolithiasis. For ureter-localized stones, SWL is often preceded by a double J stent insertion. However, fear of serious complications, including sepsis associated with stents, is often expressed. The following study assessed the impact of stent insertions on the results of SWL in patients with ureteric stones. Material and methods The study group consisted of 411 ureteric stone patients who were treated with SWL from January 2010 to December 2014. In 60 cases, treatment was preceded by ureteric stent insertion. A propensity scoring system was used to pair non-stented patients with the stented group. Success rates were assessed and compared using the chi-squared test. Multivariate logistic regression analysis was used to evaluate the influence of particular variables on the stone-free rate. Results The overall success rate was 82.2%. After matching, the success rate of the stented group was not significantly different from the control group (85.0% vs. 83.3% respectively, p = 0.80). The mean number of sessions was higher in the stented group (1.88 per patient). Stones located in the lower part of the ureter have the greatest chance of being successfully treated. Conclusions The double J stent has no influence on the outcome of SWL treatment. In view of the greater likelihood of having additional sessions, this approach should be reserved for selected cases. PMID:27551556

  16. In vitro sonoluminescence and sonochemistry studies with an electrohydraulic shock-wave lithotripter.

    PubMed

    Matula, Thomas J; Hilmo, Paul R; Bailey, Michael R; Crum, Lawrence A

    2002-09-01

    Sonoluminescence and sonochemistry from a cavitation field generated by an electrohydraulic shock-wave lithotripter were investigated as functions of spark discharge voltage (13 to 21 kV) and pulse-repetition frequency (PRF) (0.5 to 2.0 Hz). Sonochemical activity, measured with an iodide dosimeter, increased with both voltage and PRF. Sonoluminescence was measured in an acoustically matched light-tight box. The envelope of the light intensity was measured in a temporally gated region extending from the initial arrival of the shock wave (resulting in bubble compression) to the final inertial collapse of the bubble cloud, which follows hundreds of micros after passage of the shock wave. The initial compression resulted in greater sonoluminescence emissions, suggesting that the initial bubble compression due to the leading positive pressure spike from the lithotripter generated higher temperatures than the inertial collapse of the bubble. These unexpected results are consistent with some recent calculations in which the vapor pressure of the liquid limits compressional heating. PMID:12401391

  17. Use of the Hugoniot elastic limit in laser shockwave experiments to relate velocity measurements

    NASA Astrophysics Data System (ADS)

    Smith, James A.; Lacy, Jeffrey M.; Lévesque, Daniel; Monchalin, Jean-Pierre; Lord, Martin

    2016-02-01

    The US National Nuclear Security Agency has a Global Threat Reduction Initiative (GTRI) with the goal of reducing the worldwide use of high-enriched uranium (HEU). A salient component of that initiative is the conversion of research reactors from HEU to low enriched uranium (LEU) fuels. An innovative fuel is being developed to replace HEU in high-power research reactors. The new LEU fuel is a monolithic fuel made from a U-Mo alloy foil encapsulated in Al-6061 cladding. In order to support the fuel qualification process, the Laser Shockwave Technique (LST) is being developed to characterize the clad-clad and fuel-clad interface strengths in fresh and irradiated fuel plates. This fuel-cladding interface qualification will ensure the survivability of the fuel plates in the harsh reactor environment even under abnormal operating conditions. One of the concerns of the project is the difficulty of calibrating and standardizing the laser shock technique. An analytical study under development and experimental testing supports the hypothesis that the Hugoniot Elastic Limit (HEL) in materials can be a robust and simple benchmark to compare stresses generated by different laser shock systems.

  18. Effect of Shockwave Curvature on Run Distance Observed with a Modified Wedge Test

    NASA Astrophysics Data System (ADS)

    Lee, Richard; Dorgan, Robert; Sutherland, Gerrit; Benedetta, Ashley; Milby, Christopher

    2011-06-01

    The effect of wave curvature on shock initiation in PBXN-110 was investigated using a modified wedge test configuration. Various thicknesses of PBXN-110 donor slabs were used to define the shockwave curvature introduced to wedge samples of the same explosive. The donor slabs were initiated with line-wave generators so that the introduced shock would be the same shape, magnitude and duration across the entire input surface of the wedge. The shock parameters were varied for a given donor thickness via different widths of PMMA spacers placed between the donor and the wedge. A framing camera was used to observe where initiation occurred along the face of the wedge. Initiation always occurred at the center of the shock front instead of the sides like that reported by others using a much smaller test format. Results were compared to CTH calculations to indicate if there were effects associated with highly curved shock fronts that could not be adequately predicted. The run distance predicted in CTH for a 50.8 mm thick donor slab (low curvature) compared favorably with experimental results. However, results from thinner donor slabs (higher curvature) indicate a more sensitive behavior than the simulations predicted.

  19. Effect of shockwave curvature on run distance observed with a modified wedge test

    NASA Astrophysics Data System (ADS)

    Lee, Richard; Dorgan, Robert J.; Sutherland, Gerrit; Benedetta, Ashley; Milby, Christopher

    2012-03-01

    The effect of wave curvature on shock initiation in PBXN-110 was investigated using a modified wedge test configuration. Various widths of PBXN-110 donor slabs were used to define the shockwave curvature introduced to wedge samples of the same explosive. The donor slabs were initiated with line-wave generators so that the shock from the donor would be the same shape, magnitude and duration across the entire input surface of the wedge. The shock parameters were varied for a given donor with PMMA spacers placed between the donor and the wedge sample. A high-speed electronic framing camera was used to observe where initiation occurred along the face of the wedge. Initiation always occurred at the center of the shock front instead of along the sides like that reported by others using a much smaller test format. Results were compared to CTH calculations to indicate if there were effects associated with highly curved shock fronts that could not be adequately predicted. The run distance predicted in CTH for a 50.8 mm wide donor slab (low curvature) compared favorably with experimental results. However, results from thinner donor slabs (higher curvature) indicate a more sensitive behavior than the simulations predicted.

  20. Renal morphology and function immediately after extracorporeal shock-wave lithotripsy

    SciTech Connect

    Kaude, J.V.; Williams, C.M.; Millner, M.R.; Scott, K.N.; Finlayson, B.

    1985-08-01

    The acute effects of extracorporeal shock-wave lithotripsy (ESWL) on morphology and function of the kidney were evaluated by excretory urography, quantitative radionuclide renography (QRR), and magnetic resonance imaging (MRI) in 33 consecutive patients. Excretory urograms demonstrated an enlarged kidney in seven (18%) of 41 treatments and partial or complete obstruction of the ureter by stone fragments after 15 (37%) of 41 treatments. Total effective renal plasma flow (ERPF) was not changed after ESWL, but the percentage ERPF of the treated kidney was decreased by more than 5% in 10 (30%) of 33 cases. QRR images showed partial parenchymal obstruction in 10 (25%) of 41 teated kidneys and total parenchymal obstruction in 9 (22%). MRI disclosed one or more abnormalities in 24 (63%) of 38 treated kidneys. Treated kidneys were normal by all three imaging methods in 26% and abnormal by one or more tests in 74% of cases. The morphologic and functional changes are attributed to renal contusion resulting in edema and extravasation of urine and blood into the interstitial, subcapsular, and perirenal spaces.

  1. Update on the efficacy of extracorporeal shockwave treatment for myofascial pain syndrome and fibromyalgia.

    PubMed

    Ramon, Silvia; Gleitz, Markus; Hernandez, Leonor; Romero, Luis David

    2015-12-01

    Chronic muscle pain syndrome is one of the main causes of musculoskeletal pathologies requiring treatment. Many terms have been used in the past to describe painful muscular syndromes in the absence of evident local nociception such as myogelosis, muscle hardening, myalgia, muscular rheumatism, fibrositis or myofascial trigger point with or without referred pain. If it persists over six months or more, it often becomes therapy resistant and frequently results in chronic generalized pain, characterized by a high degree of subjective suffering. Myofascial pain syndrome (MPS) is defined as a series of sensory, motor, and autonomic symptoms caused by a stiffness of the muscle, caused by hyperirritable nodules in musculoskeletal fibers, known as myofascial trigger points (MTP), and fascial constrictions. Fibromyalgia (FM) is a chronic condition that involves both central and peripheral sensitization and for which no curative treatment is available at the present time. Fibromyalgia shares some of the features of MPS, such as hyperirritability. Many treatments options have been described for muscle pain syndrome, with differing evidence of efficacy. Extracorporeal Shockwave Treatment (ESWT) offers a new and promising treatment for muscular disorders. We will review the existing bibliography on the evidence of the efficacy of ESWT for MPS, paying particular attention to MTP (Myofascial Trigger Point) and Fibromyalgia (FM).

  2. Disseminated tuberculosis after extracorporeal shock-wave lithotripsy in an AIDS patient presenting with urosepsis.

    PubMed

    Tourchi, Ali; Ebadi, Maryam; Hosseinzadeh, Alireza; Shabaninia, Mahsa

    2014-03-01

    Haematogenous dissemination of undiagnosed urinary tuberculosis after performing extracorporeal shock-wave lithotripsy (ESWL) is extremely rare. Herein, we report a 41-year-old male who presented with urosepsis to the emergency room; catheterization was performed and retention resolved. He had a tattoo on his left arm and a five-year history of intravenous drug use. Blood tests indicated anaemia, leukocytosis, elevated CRP and ESR and mild hyponatraemia; haematuria, moderate bacteriuria and 2+ proteinuria on urinanalysis were observed. Chest X-ray revealed lesions suggestive of miliary tuberculosis, which was confirmed by chest CT scan. Brain CT and MRI suggested brain involvement in the setting of tuberculosis. On further investigations, HIV infection and hepatitis C seropositivity were detected and the patient remained in a coma for five days with a Glasgow Coma Scale of 6/15. Finally, the diagnosis of haematogenous dissemination of tuberculosis following lithotripsy was established. Anti-tuberculosis and anti-retroviral therapy were prescribed and monthly follow-up visits were scheduled. In conclusion, in a patient diagnosed with ureterolithiasis, a thorough history and physical examination, with specific attention to HIV and tuberculosis predisposing factors, should be carried out and preoperative screening tests considering the possibility of urinary tuberculosis are required. Finally, if urinary tuberculosis is detected, ESWL must be postponed until after appropriate treatment of tuberculosis. PMID:23970650

  3. Prostaglandin E2 and Connexin 43 crosstalk in the osteogenesis induced by extracorporeal shockwave.

    PubMed

    Chen, Youbin; Xu, Jiankun; Liao, Haojie; Ma, Zebin; Zhang, Yuantao; Chen, Hongjiang; Huang, Zhonglian; Hu, Jun

    2016-09-01

    As a type of mechanical stimulation, extracorporeal shockwave (ESW) has been widely used in the clinic to treat bone fracture delayed union and non-unions. A large number of studies have shown beneficial effects of ESW in promoting fracture healing by inducing bone regeneration; however, the underlying mechanisms remain unclear. ESW has been shown to induce the production of prostaglandin E2 (PGE2), which is essential for gap junction intercellular communication in response to mechanical stress. Among the 19 known gap junction subunits, connexin43 (Cx43) is the most prevalent for mediating the response of mechanical stress. However, to our knowledge, the effect of ESW on Cx43 expression has not been reported before. Herein, we propose that a crosstalk between PGE2 and Cx43 is involved in the enhancement of osteogenesis induced by ESW. We review the currently available data to propose an unrevealed, but important mechanism via which ESW treatment affects osteogenic differentiation of bone marrow stromal cells. PMID:27515217

  4. Effect of shock-wave therapy on patellar tendinopathy in a rabbit model.

    PubMed

    Hsu, Robert Wen-Wei; Hsu, Wei-Hsiu; Tai, Ching-Lung; Lee, Kam-Fai

    2004-01-01

    This study investigated the effect of shock-wave therapy (SWT) on collagenase induced tendinopathy in the rabbit patellar tendon. Eighteen rabbits were treated by ultrasonography-guided injection of 0.025 ml collagenase into the patellar tendon in both knees. After tendinopathy was confirmed at 3 weeks post-treatment by the histological examination, SWT was initiated to the right patellar tendon involving 1500 cycles at 0.29 mJ/mm2 in two separated weekly courses from 4 weeks post-treatment. The rabbits were randomly divided into two groups, which were sacrificed at the 4th and 16th week after SWT, respectively. The histological examination, the mechanical and biochemical tests then were performed. The ultimate tensile load in the SWT tendon increased 7.03% at 4 week and 10.34% at 16 week after treatment as compared to the sham group. Hydroxyproline concentrations increased in the SWT tendons over both the 4 and 16 weeks after treatment. Moreover, the pyridinoline concentration increased at the 4th week but decreased at 16th week as compared to the sham group. The histological examination demonstrated increased blast-like tenocyte at the 4th week, while more mature tenocyte with neovasculization at the 16th week. The result obtained here validates the effectiveness of the SWT in the established tendinopathy. SWT may increase collagen synthesis and collagen crosslink formation during early healing process.

  5. Shooter position estimation with muzzle blast and shockwave measurements from separate locations

    NASA Astrophysics Data System (ADS)

    Grasing, David

    2016-05-01

    There are two acoustical events associated with small arms fire: the muzzle blast (created by bullets being expelled from the barrel of the weapon), and the shockwave (created by bullets which exceed the speed of sound). Assuming the ballistics of a round are known, the times and directions of arrival of the acoustic events furnish sufficient information to determine the origin of the shot. Existing methods tacitly assume that it is a single sensor which makes measurements of the times and direction of arrival. If the sensor is located past the point where the bullet goes transonic or if the sensor is far off the axis of the shot line a single sensor localization become highly inaccurate due to the ill-conditioning of the localization problem. In this paper, a more general approach is taken which allows for localizations from measurements made at separate locations. There are considerable advantages to this approach, the most noteworthy of which is the improvement in localization accuracy due to the improvement in the conditioning of the problem. Additional benefits include: the potential to locate in cases where a single sensor has insufficient information, furnishing high quality initialization to data fusion algorithms, and the potential to identify the round from a set of possible rounds.

  6. Update on the efficacy of extracorporeal shockwave treatment for myofascial pain syndrome and fibromyalgia.

    PubMed

    Ramon, Silvia; Gleitz, Markus; Hernandez, Leonor; Romero, Luis David

    2015-12-01

    Chronic muscle pain syndrome is one of the main causes of musculoskeletal pathologies requiring treatment. Many terms have been used in the past to describe painful muscular syndromes in the absence of evident local nociception such as myogelosis, muscle hardening, myalgia, muscular rheumatism, fibrositis or myofascial trigger point with or without referred pain. If it persists over six months or more, it often becomes therapy resistant and frequently results in chronic generalized pain, characterized by a high degree of subjective suffering. Myofascial pain syndrome (MPS) is defined as a series of sensory, motor, and autonomic symptoms caused by a stiffness of the muscle, caused by hyperirritable nodules in musculoskeletal fibers, known as myofascial trigger points (MTP), and fascial constrictions. Fibromyalgia (FM) is a chronic condition that involves both central and peripheral sensitization and for which no curative treatment is available at the present time. Fibromyalgia shares some of the features of MPS, such as hyperirritability. Many treatments options have been described for muscle pain syndrome, with differing evidence of efficacy. Extracorporeal Shockwave Treatment (ESWT) offers a new and promising treatment for muscular disorders. We will review the existing bibliography on the evidence of the efficacy of ESWT for MPS, paying particular attention to MTP (Myofascial Trigger Point) and Fibromyalgia (FM). PMID:26363497

  7. Development of a new diagnostic sensor for extra-corporeal shock-wave lithotripsy

    NASA Astrophysics Data System (ADS)

    Fedele, F.; Coleman, A. J.; Leighton, T. G.; White, P. R.; Hurrell, A. M.

    2004-01-01

    Extracorporeal shock-wave lithotripsy is the leading technique used in urology for the non-invasive treatment of kidney and ureteric stones. The stone is comminuted by thousands of ultrasound shocks, into fragments small enough to be naturally passed. Since the technique was introduced in the 1980 different generations of lithotripters have been developed. Nevertheless the alignment systems (x-ray, ultrasound) still have some limitations (indeed, the tighter focusing of newer lithotripter reduces the tolerance for misalignment) and there is no capability for on-line monitoring of the degree of fragmentation of the stone. There is 50% incidence of re-treatments, possibly due to these deficiencies. The objective of this research is to design a new passive acoustic sensor, exploiting the secondary acoustic emission generated during the treatment, which could be used as a diagnostic device for lithotripsy. With a passive cylindrical cavitation detector, developed by the National Physical Laboratory, it was possible to detect these emissions in a laboratory lithotripter, and it was shown that they contain information on the degree of stone fragmentation and stone location. This information could be used to perform the desired monitoring and to improve the stone targeting. In collaboration with Precision Acoustic Ltd, some clinical prototypes were developed and tested to verify the relevance of these preliminary results. Clinical results are presented.

  8. Laser-induced shock-wave lithotripsy of canine urocystoliths and nephroliths

    NASA Astrophysics Data System (ADS)

    Woods, J. P.; Bartels, Kenneth E.; Stair, Ernest L.; Schafer, Steven A.; Nordquist, Robert E.

    1997-05-01

    Urolithiasis is a common disease affecting dogs which can sometimes be treated with dietary and medical protocols. In many cases, however, medical management cannot be employed because the dietary restrictions are contraindicated, effective medical dissolution protocols for the calculi (uroliths) do not exist, or obstruction by the calculi may result in deterioration of renal function during the time required for medical dissolution. At present, the management of medically untreatable calculi has been surgical removal which may result in temporary but dramatic decrease in renal function, irreversible loss of damaged nephrons, and significant risk, particularly for bilateral or recurrent nephroliths. An innovative technique for the removal of these uroliths would involve laser lithotripsy which transforms light energy into acoustical energy generating a shock wave sufficient to fragment stones (photoacoustic ablation). The laser is transmitted via quartz fibers which are small and flexible and can be used under direct vision through endoscopes resulting in effective fragmentation with little surrounding tissue damage. Lasers are becoming increasingly more utilized in veterinary medicine, in contrast to the limited availability of other non-invasive methods of treatment of nephroliths (i.e. extracorporeal shock-wave lithotripsy).

  9. Integral equation model for warm and hot dense mixtures.

    PubMed

    Starrett, C E; Saumon, D; Daligault, J; Hamel, S

    2014-09-01

    In a previous work [C. E. Starrett and D. Saumon, Phys. Rev. E 87, 013104 (2013)] a model for the calculation of electronic and ionic structures of warm and hot dense matter was described and validated. In that model the electronic structure of one atom in a plasma is determined using a density-functional-theory-based average-atom (AA) model and the ionic structure is determined by coupling the AA model to integral equations governing the fluid structure. That model was for plasmas with one nuclear species only. Here we extend it to treat plasmas with many nuclear species, i.e., mixtures, and apply it to a carbon-hydrogen mixture relevant to inertial confinement fusion experiments. Comparison of the predicted electronic and ionic structures with orbital-free and Kohn-Sham molecular dynamics simulations reveals excellent agreement wherever chemical bonding is not significant.

  10. CFD analysis of dense gas dispersion in indoor environment for risk assessment and risk mitigation.

    PubMed

    Siddiqui, M; Jayanti, S; Swaminathan, T

    2012-03-30

    Environmental risks are inherent in the operation of any complex chemical process industry. The indoor release of hazardous chemicals that are denser than air is a topic of special concern, since dense clouds tend to persist at ground level or human breath level which leads to a magnification of their harmful potential. In the present work, we propose a computational fluid dynamics (CFD) based model for indoor risk assessment considering accidental release of a sustained, small, undetected leak of a dense toxic gas (chlorine) in an industrial indoor environment. Results from simulations show that the denser chlorine gas spreads like a liquid and flows all along the floor. At the same time, its concentration at a point away from the ground level increases slowly, thus showing that both stratification and dilution effects are present as the dense gas spreads. The implications of this spreading pattern from a risk assessment and risk mitigation point of view are discussed.

  11. Fluid flow into vertical fractures from a point source

    SciTech Connect

    Clark, P.E.; Zhu, Q.

    1995-03-01

    Flow into a fracture from a point source recently has been the focus of attention in the petroleum industry. The suggestion has been made that, in this flow configuration, convection (gravity-driven flow) would dominate Stokes`-type settling for determining final proppant distribution. The theory is that when a dense fluid flows into a fracture filled with a less dense fluid from a point source, the density of the fluid will force it to the bottom of the fracture. This clearly happens when the two fluids have low viscosity. However, viscosity of both the fluid in the fracture and the displacing fluid and nonuniformities in the fracture influence displacement process significantly. Results presented in this study clearly show the effects of viscosity and fracture nonuniformity on the convective settling mechanism.

  12. H3+ in dense and diffuse clouds.

    PubMed

    McCall, B J; Hinkle, K H; Geballe, T R; Oka, T

    1998-01-01

    Interstellar H3+ has been detected in dense as well as diffuse clouds using three 3.7 microns infrared spectral lines of the nu 2 fundamental band. Column densities of H3+ from (1.7-5.5) x 10(14) cm-2 have been measured in dense clouds in absorption against the infrared continua of the deeply embedded young stellar objects GL2136, W33A, MonR2 IRS 3, GL961E, and GL2591. Strong and broad H3+ absorptions have been detected in dense and diffuse clouds towards GC IRS 3 and GCS3-2 in the region of the galactic center. A large column density of H3+, comparable to that of a dense cloud, has been detected towards the visible star Cygnus OB2 No. 12, which has a line of sight that crosses mostly diffuse clouds. The H3+ chemistry of dense and diffuse clouds are discussed using a very simple model. Some future projects and problems are discussed.

  13. Fluid Shifts

    NASA Technical Reports Server (NTRS)

    Stenger, M.; Hargens, A.; Dulchavsky, S.; Ebert, D.; Lee, S.; Lauriie, S.; Garcia, K.; Sargsyan, A.; Martin, D.; Ribeiro, L.; Lui, J.; Macias, B.; Arbeille, P.; Danielson, R.; Chang, D.; Johnston, S.; Ploutz-Snyder, R.; Smith, S.

    2016-01-01

    NASA is focusing on long-duration missions on the International Space Station (ISS) and future exploration-class missions beyond low-Earth orbit. Visual acuity changes observed after short-duration missions were largely transient, but more than 50% of ISS astronauts experienced more profound, chronic changes with objective structural and functional findings such as papilledema and choroidal folds. Globe flattening, optic nerve sheath dilation, and optic nerve tortuosity also are apparent. This pattern is referred to as the visual impairment and intracranial pressure (VIIP) syndrome. VIIP signs and symptoms, as well as postflight lumbar puncture data, suggest that elevated intracranial pressure (ICP) may be associated with the spaceflight-induced cephalad fluid shifts, but this hypothesis has not been tested. The purpose of this study is to characterize fluid distribution and compartmentalization associated with long-duration spaceflight, and to correlate these findings with vision changes and other elements of the VIIP syndrome. We also seek to determine whether the magnitude of fluid shifts during spaceflight, as well as the VIIP-related effects of those shifts, is predicted by the crewmember's preflight conditions and responses to acute hemodynamic manipulations (such as head-down tilt). Lastly, we will evaluate the patterns of fluid distribution in ISS astronauts during acute reversal of fluid shifts through application of lower body negative pressure (LBNP) interventions to characterize and explain general and individual responses. METHODS: We will examine a variety of physiologic variables in 10 long-duration ISS crewmembers using the test conditions and timeline presented in the Figure below. Measures include: (1) fluid compartmentalization (total body water by D2O, extracellular fluid by NaBr, intracellular fluid by calculation, plasma volume by CO rebreathe, interstitial fluid by calculation); (2) forehead/eyelids, tibia, calcaneus tissue thickness (by

  14. Fluid inflation

    SciTech Connect

    Chen, X.; Firouzjahi, H.; Namjoo, M.H.; Sasaki, M. E-mail: firouz@ipm.ir E-mail: misao@yukawa.kyoto-u.ac.jp

    2013-09-01

    In this work we present an inflationary mechanism based on fluid dynamics. Starting with the action for a single barotropic perfect fluid, we outline the procedure to calculate the power spectrum and the bispectrum of the curvature perturbation. It is shown that a perfect barotropic fluid naturally gives rise to a non-attractor inflationary universe in which the curvature perturbation is not frozen on super-horizon scales. We show that a scale-invariant power spectrum can be obtained with the local non-Gaussianity parameter f{sub NL} = 5/2.

  15. Evidence for CO2-rich fluids in rocks from the type charnockite area near Pallavaram, Tamil Nadu

    NASA Technical Reports Server (NTRS)

    Hansen, E.; Hunt, W.; Jacob, S. C.; Morden, K.; Reddi, R.; Tacy, P.

    1988-01-01

    Fluid inclusion and mineral chemistry data was presented for samples from the type charnockite area near Pallavaram (Tamil Nadu, India). The results indicate the presence of a dense CO2 fluid phase, but the data cannot distinguish between influx of this fluid from elsewhere or localized migration of CO2-rich fluids associated with dehydration melting.

  16. Coalescence preference in densely packed microbubbles

    SciTech Connect

    Kim, Yeseul; Lim, Su Jin; Gim, Bopil; Weon, Byung Mook

    2015-01-13

    A bubble merged from two parent bubbles with different size tends to be placed closer to the larger parent. This phenomenon is known as the coalescence preference. Here we demonstrate that the coalescence preference can be blocked inside a densely packed cluster of bubbles. We utilized high-speed high-resolution X-ray microscopy to clearly visualize individual coalescence events inside densely packed microbubbles with a local packing fraction of ~40%. Thus, the surface energy release theory predicts an exponent of 5 in a relation between the relative coalescence position and the parent size ratio, whereas our observation for coalescence in densely packed microbubbles shows a different exponent of 2. We believe that this result would be important to understand the reality of coalescence dynamics in a variety of packing situations of soft matter.

  17. Coalescence preference in densely packed microbubbles

    DOE PAGES

    Kim, Yeseul; Lim, Su Jin; Gim, Bopil; Weon, Byung Mook

    2015-01-13

    A bubble merged from two parent bubbles with different size tends to be placed closer to the larger parent. This phenomenon is known as the coalescence preference. Here we demonstrate that the coalescence preference can be blocked inside a densely packed cluster of bubbles. We utilized high-speed high-resolution X-ray microscopy to clearly visualize individual coalescence events inside densely packed microbubbles with a local packing fraction of ~40%. Thus, the surface energy release theory predicts an exponent of 5 in a relation between the relative coalescence position and the parent size ratio, whereas our observation for coalescence in densely packed microbubblesmore » shows a different exponent of 2. We believe that this result would be important to understand the reality of coalescence dynamics in a variety of packing situations of soft matter.« less

  18. Propagation of light in a Dense Medium

    NASA Astrophysics Data System (ADS)

    Masood, Samina; Saleem, Iram

    Propagation of light is studied in a very dense system. Renormalization scheme of QED is used to understand the propagation of light in a hot and dense medium. We consider a medium of a very large chemical potential with relatively small temperature. The generalized results of vacuum polarization of photon in a hot and dense medium is used to study the behavior of light in such a system. Our hypothetical system corresponds to a heat bath of electrons at an equilibrium temperature and the density of electrons is larger as compared to the temperature of the medium. Such type of systems have previously been identified as classical systems because the chemical potential is large enough to dominate temperature.

  19. Fluid Shifts

    NASA Technical Reports Server (NTRS)

    Stenger, Michael B.; Hargens, Alan R.; Dulchavsky, Scott A.; Ebert, Douglas J.; Lee, Stuart M. C.; Laurie, Steven S.; Garcia, Kathleen M.; Sargsyan, Ashot E.; Martin, David S.; Liu, John; Macias, Brandon R.; Arbeille, Philippe; Danielson, Richard; Chang, Douglas; Gunga, Hanns-Christian; Johnston, Smith L.; Westby, Christian M.; Ploutz-Snyder, Robert J.; Smith, Scott M.

    2016-01-01

    We hypothesize that microgravity-induced cephalad fluid shifts elevate intracranial pressure (ICP) and contribute to VIIP. We will test this hypothesis and a possible countermeasure in ISS astronauts.

  20. Amniotic fluid

    MedlinePlus

    ... baby is born), or gestational diabetes . Too little amniotic fluid is known as oligohydramnios. This condition may occur with late pregnancies, ruptured membranes, placental dysfunction , or fetal abnormalities. Abnormal amounts of ...