Search results for "Shock wave"
showing 10 items of 194 documents
Low-frequency extracorporeal shock wave lithotripsy improves renal pelvic stone disintegration in a pig model.
2009
OBJECTIVE To compare disintegration rates for renal stones treated by 60 vs 120 shock waves (SW)/min at the same energy settings, using standardized validated artificial stones in a pig model. MATERIALS AND METHODS Gypsum artificial stones (13 × 6 mm) were inserted into the renal pelvis on either side of 12 anaesthetized pigs by open surgery. Extracorporeal SW lithotripsy (ESWL) was applied using a new electromagnetic lithotripter (Lithoskop®, Siemens AG Healthcare, Munich, Germany) at 60 and 120 SW/min; 3000 SW were applied to each kidney with the same energy settings. Stone fragments were collected after nephrectomy, passed through calibrated test sieves, and weighed. Fragment size catego…
Surgical aspects of urolithiasis in children.
1991
Operative management of renal calculi has changed radically in the last decade. New operative techniques. the use of intra-operative ultrasound and Doppler sonography have even made possible the removal of complete staghorn calculi in short and kidney-preserving procedures. The introduction of percutaneous nephrolithotomy and stone extraction using a specially designed ureteroscope and, above all, the clinical application of extracorporeal shock wave lithotripsy have made stone surgery less invasive and have provided a higher rate of preservation of kidney function.
Extracorporeal shock wave lithotripsy (ESWL): alternatives and adjuvant procedures
1985
Within a short time, extensive statistics on ESWL have documented its efficiency in the treatment of most renal and ureteral stones. Approximately 20% of all stone patients, however, require additional or other forms of therapy, such as URS, PNL, or surgery. Up to now, the differential indications for these procedures have not been completely established. A crucial factor for successful application of ESWL is stone volume and localization. Large stones with a central stone mass may be successfully treated by combining ESWL and PNL, while surgery is still preferred in those with a peripheral stone mass.
Detailed characterization of laboratory magnetized super-critical collisionless shock and of the associated proton energization
2021
Collisionless shocks are ubiquitous in the Universe and are held responsible for the production of nonthermal particles and high-energy radiation. In the absence of particle collisions in the system, theory shows that the interaction of an expanding plasma with a pre-existing electromagnetic structure (as in our case) is able to induce energy dissipation and allow shock formation. Shock formation can alternatively take place when two plasmas interact, through microscopic instabilities inducing electromagnetic fields that are able in turn to mediate energy dissipation and shock formation. Using our platform in which we couple a rapidly expanding plasma induced by high-power lasers (JLF/Titan…
Extracorporeal shock wave therapy as a potential therapeutic tool for breast cancer related lymphedema: a narrative review of in vitro, animal and cl…
2021
Background: The treatment of breast cancer related lymphedema (BCRL) focuses on the alleviation symptoms. One of the innovative, non-invasive therapies used for this condition is extracorporeal shock wave therapy (ESWT). Aim of the study: To review the available literature and evaluate the effectiveness of ESWT in the treatment of secondary lymphedema (in vitro works, animal experiments) and lymphedema associated with the treatment of breast cancer. Material and methods: The scientific literature review was conducted from October to December 2020. The review was carried out by searching scientifically recognized medical databases, including PubMed, MEDLINE and PEDro. Date restrictions were …
Assessment of the fundamental flexural guided wave in cortical bone by an ultrasonic axial-transmission array transducer
2013
Abstract The fundamental flexural guided wave (FFGW), as modeled, for example, by the A0 Lamb mode, is a clinically useful indicator of cortical bone thickness. In the work described in this article, we tested so-called multiridge-based analysis, based on the crazy climber algorithm and short-time Fourier transform, for assessment of the FFGW component recorded by a clinical array transducer featuring a limited number of elements. Methods included numerical finite-element simulations and experiments in bone phantoms and human radius specimens ( n = 41). The proposed approach enabled extraction of the FFGW component and determination of its group velocity. This group velocity was in good ag…
Shock-cloud interaction in the Vela SNR II. Hydrodynamic model
2006
In the framework of the study of the X-ray and optical emission in supernova remnants we focus on an isolated X-ray knot in the northern rim of the Vela SNR (Vela FilD), whose X-ray emission has been studied and discussed in Paper I. We aim at understanding the physical origin of the X-ray and optical emission in FilD, at understanding the role of the different physical processes at work, and at obtaining a key for the interpretation of future X-ray observations of SNRs. To this end we have pursued an accurate ``forward'' modeling of the interaction of the Vela SNR shock with an ISM cloud. We perform hydrodynamic simulations and we directly compare the observables synthesized from the simul…
X-rays from protostellar jets: emission from continuous flows
2006
Recently X-ray emission from protostellar jets has been detected with both XMM-Newton and Chandra satellites, but the physical mechanism which can give rise to this emission is still unclear. We performed an extensive exploration of a wide space of the main parameters influencing the jet/ambient interaction. Aims include: 1) to constrain the jet/ambient interaction regimes leading to the X-ray emission observed in Herbig-Haro objects in terms of the emission by a shock forming at the interaction front between a continuous supersonic jet and the surrounding medium; 2) to derive detailed predictions to be compared with optical and X-ray observations of protostellar jets; 3) to get insight int…
Numerical study of a multiscale expansion of the Korteweg de Vries equation and Painlev\'e-II equation
2007
The Cauchy problem for the Korteweg de Vries (KdV) equation with small dispersion of order $\e^2$, $\e\ll 1$, is characterized by the appearance of a zone of rapid modulated oscillations. These oscillations are approximately described by the elliptic solution of KdV where the amplitude, wave-number and frequency are not constant but evolve according to the Whitham equations. Whereas the difference between the KdV and the asymptotic solution decreases as $\epsilon$ in the interior of the Whitham oscillatory zone, it is known to be only of order $\epsilon^{1/3}$ near the leading edge of this zone. To obtain a more accurate description near the leading edge of the oscillatory zone we present a…
On the existence of a reverse shock in magnetized gamma-ray burst ejecta
2007
The role of magnetic fields in gamma-ray burst (GRB) flows remains controversial. The study of the early afterglow phases and, in particular, of the reverse shock dynamics and associated emission offers a promising probe of the magnetization of the ejecta. In this paper, we derive the conditions for the existence of a reverse shock in arbitrarily magnetized ejecta that decelerate and interact with the circumburst medium. Both constant and wind-like density profiles are considered. We show, in contrast to previous estimates, that ejecta with magnetization σ0 >∼ 1 are not crossed by a reverse shock for a large fraction of the parameter space relevant to GRB flows. Allowing for shell spreading…