Shock Wave Research Articles

Optoelectronic and photoacoustic waves in rotating excited semiconductor subjected to thermal shock

In this study, the impact of rotation on the transmission of optical acoustic waves, arising from the movement of the optical carrier within an elastic thermal environment, is examined through theoretical analysis. The theoretical framework incorporates the interaction between acoustic waves and thermomechanics to formulate governing equations specific to a semiconductor medium. The fundamental equations of the physical model, influenced by photothermal and thermoelastic principles, are deduced mathematically while considering the presence of rotation. The model studied the medium under a thermal shock wave from thermal stress resulting from light-induced temperature elevation that is not fixed but decaying over time. The mathematical model is solvable using the normal mode method. The model’s numerical solutions provide access to all physical fields within the physical domain, encompassing displacement, temperature, acoustic pressure, mechanical stress, and carrier density diffusion. Utilizing the harmonic wave method, a two-dimensional graphical representation of the rotation parameter with and without the influence of the decay parameter is obtained. The theoretical analysis involves comparison, analysis, and discussion of the effects of these parameters investigated.

Aeroelastic Effects in Supersonic Shock-Turbulent Boundary Layer Interaction over Flexible Panels

The dynamic coupling between a Mach 1.94 shock wave/turbulent boundary layer interaction (SBLI) and a flexible panel is investigated. High-order numerical simulations are performed for distinctly different dynamic panel motions and rigid snapshots of their maximum deflected shape. They are compared with a baseline interaction over a rigid planar wall. The panel’s dynamic surface motions were obtained from the Air Force Research Laboratory (AFRL) wind tunnel experiments. The primary aim of the study was to determine whether there were any differences in the flow pressure loading on the compliant panel due to the various rigid and dynamic deformations considered. The results show that the examined panel deformations increase the SBLI size near the panel midpoint, where the deformation amplitude tends to be the largest. Relative to the rigid planar case, the examined surface deformations cause the mean-flow high-pressure surface loading caused by the impinging shock wave to shift downstream along the compliant panel midspan, albeit by a small amount. The spectrogram of the dynamic deformation and the flow surface pressure response suggests that the two are strongly coupled at the dominant (primary) mode but less so at the secondary modes. Although the primary mode frequencies overlap, they do not exactly match, with the pressure response frequency always being slightly higher in all three cases. The rigid deformations did not enhance the pressure power content at the SBLI. However, pre-SBLI and near the panel leading edge, the pressure power spectrum weakly increased throughout the resolved frequency range and overlapped with the onset of the amplification found in the dynamic deformation cases. Post-SBLI, the rigid deformations cause a weak enhancement at frequencies below 1 kHz, which closely match the dominant and secondary pressure response frequencies obtained in the dynamic cases.

General theory of diaphragm rupture in a shock tunnel

As the flow field starting device is in a shock tunnel, the rupture performance of the diaphragm directly influences the successful formation of the shock wave. The general theory of diaphragm rupture in shock tunnels is proposed first in this paper. The reasons for diaphragm rupture are explained fundamentally. The existing ideologies on diaphragm rupture are unified, and two hypotheses with corresponding methods are introduced. In the ideal diaphragm, diaphragm rupture pressure or rupture time can be predicted by considering the diaphragm opening as a throat through a diaphragm opening aperture. In the non-ideal diaphragm, the control of diaphragm rupture pressure can be realized by considering nominal rupture stress and grooved thickness. The correctness of the general theory of diaphragm rupture is proved through argumentation and based on experimental results of the literature. The general theory of diaphragm rupture can be used to predict the diaphragm rupture behavior of any shock tunnel worldwide and avoid the risk of shearing of petals on the diaphragm caused by the impact load. A new system of diaphragm rupture theory is constituted, and it is of significant importance for the efficient operation of shock tunnel equipment.

Enhancing improved advection upstream splitting method on triangular grids: A hybrid approach for improved stability and accuracy in compressible flow simulations

This paper introduces NAUSM+M+AUFS (New Improved Advection Upstream Splitting Method Plus Artificially Upstream Flux Vector Splitting), a novel hybrid computational scheme for simulating compressible flows on triangular grids. The AUSM+M (Improved Advection Upstream Splitting Method) method is enhanced through two key modifications to boost numerical stability and robustness in high Mach number and hypersonic flows. The first modification redefines the interfacial numerical sound velocity, reducing shock anomalies and improving shock-capturing by integrating velocity and characteristic sound speed parameters. The second modification addresses the insufficiency of the pressure flux dissipation term at supersonic speeds by introducing a formulation that increases dissipation proportionally to the Mach number, thereby enhancing performance in high-speed flows. These enhancements constitute the NAUSM+M method. The NAUSM+M+AUFS scheme combines the strengths of NAUSM+M and AUFS (Artificially Upstream Flux Vector Splitting) methods, particularly in overcoming the limitations of NAUSM+M in handling shock instabilities and the carbuncle phenomenon on structure triangular grids. A dynamic switching function adjusts the weighting between NAUSM+M and AUFS, optimizing accuracy and stability based on local flow conditions. Numerical tests demonstrate that NAUSM+M+AUFS significantly outperforms AUSM+M, NAUSM+M, and AUFS, effectively eliminating the carbuncle phenomenon and providing smooth shock wave contours. In steady flow analysis, the new hybrid method achieves convergence speeds comparable to AUFS and shows 15% to 45% superior convergence accelerating than AUSM+M, depending on the convergence rate. In addition, in steady flow analysis, the accuracy of NAUSM+M+AUFS is 46% better than that of AUFS. This approach represents a significant advancement, offering a robust, accurate, and efficient solution for high-speed aerodynamic simulations, with broad applicability across various compressible flow challenges.

Ultrasound-Guided Needling Combined With High- or Low-Energy Extracorporeal Shock Wave Therapy Versus Needling Alone for Calcified Rotator Cuff: A Retrospective Study.

Rotator cuff calcific tendinitis is a common shoulder joint disorder. Nonsurgical treatment methods, including multiple needling and extracorporeal shock wave therapy (ESWT), can effectively treat calcific tendinitis. To evaluate the clinical results and radiological outcomes of treatment with ultrasound-guided needling (UGN) alone versus UGN with high-energy ESWT (UGN-H) or UGN with low-energy ESWT (UGN-L) in patients with calcific tendinitis of the rotator cuff. Cohort study; Level of evidence, 3. Outpatient records for patients with calcific tendinitis of the rotator cuff were evaluated retrospectively. Patients were grouped into those treated with UGN-H, UGN-L, or controls with UGN alone. The visual analog scale (VAS) for pain, American Shoulder and Elbow Surgeons (ASES) scores, Constant-Murley scores, and radiographic evaluation to assess calcification size were available before treatment and at 3, 6, and 12 months after the first treatment. Post event pairwise analysis to analyze score differences between treatment groups was used. Overall, 130 patients were included for analysis (42 UGN-H, 44 UGN-L, and 44 with UGN alone). At 3 months, the VAS scores were UGN-H (4.13 ± 0.84; P < .001) and UGN-L (4.47 ± 1.01; P < .001) which were significantly better than UGN alone (5.35 ± 1.00) in terms of the VAS score; however, the difference was not significant between UGN-H and UGN-L. These differences persisted at months 6 and 12 (6 months: UGN-H, 2.66 ± 1.00; P < .001; UGN-L, 3.16 ± 1.05; P = .033; 12 months: UGN-H, 1.93 ± 0.43; P < .001; UGN-L, 2.04 ± 0.46; P < .001). The results of the ASES and Constant-Murley scores were similar to those of the VAS score. In terms of radiographic outcome, follow-up at months 3, 6, and 12 revealed that UGN-H and UGN-L were superior to UGN alone at removing calcification (median 95% CI; 3 months: UGN-H, 1.4 mm2 [1.08, 7.25 mm2); P = .002; UGN-L, 5.79 mm2 (1.17, 7.85 mm2]; P = .041; 6 months: UGN-H, 0.91 mm2 [0, 1.15 mm2); P < .001; UGN-L, 1.13 mm2 [0.84, 5.10 mm2]; P < .001; 12 months: UGN-H, 0 mm2 [0, 0 mm2]; P < .001; UGN-L, 0 mm2 (0, 4.33 mm2]; P = .023). There was no significant difference between UGN-H and UGN-L at the month 3 follow-up, but the month 6 and 12 follow-ups revealed that UGN-H was more effective at removing calcification compared with UGN-L. The study demonstrated that, for pain relief and recovery of shoulder joint function, UGN + ESWT was significantly superior to UGN alone. No significant difference was observed between different energy levels of ESWT. UGN + ESWT was significantly superior to UGN alone on radiographic evaluation. Furthermore, UGN-H performed better radiographically with reducing calcifications compared with UGN-L at 12 months.

Effective cracking of heavy crude oil by using shock-induced nanobubble collapse: A molecular dynamics study

We investigate molecular mechanisms of hydrocarbon cracking in heavy crude oil promoted by nanobubble collapse due to ultrasound-originated shock wave. Our millions-atom molecular dynamics simulations reveal rapid flow of molecules, causing nanobubble collapse and formation of energetic nanojet with a mushroom-like shape. The nanojet apex exhibits extremely high temperature before and just after the bubble collapse, which makes a favorable condition for effective cracking of paraffin molecules. The cracking rate and portion of nanobubble-containing systems are larger than those of perfect system before the bubble collapse, and larger size of nanobubble is preferable for the cracking. The cracking efficiency is improved for the paraffin molecules with longer carbon chain.

Fluid-thermally-solid coupling analysis of aircraft leading edge

Abstract Aircraft are affected by aerodynamic loads during operation. To analyze the impact of the leading edge structure of aircraft under different flight angles of attack, this paper uses the fluid-heat-solid coupling calculation method. It combines CFD with the thermal-structure field solver and uses simulation software, with a flight altitude of 15 km, flight speed of 6 Ma, and flight Angle of attack of 0 ~ 20°. Considering the change of material parameters with temperature, the coupling of multiple physical fields in aircraft is simulated and analyzed. The simulation results show that the existence of the flight angle of attack makes the flow field shock wave position of the aircraft closer to the windward surface of the structure. The angle of attack exacerbates the structural deformation of the aircraft, with the maximum deformation occurring at a 20° angle of attack, which is 3.06 mm. The research results can provide a reference for aircraft design.

Analysis of the effects of combined suction on hypersonic inlet starting performance

Abstract Taking a two-dimensional inlet (Case 1) as the original inlet, the combined suction schemes are designed and their influences on the self-starting ability of the inlet are studied. The flow fields at the design point and the self-starting progress of the inlets are calculated by the numerical simulation method. The results show that the three-slot combination scheme (Case 2) leads to the reduction of the mass flow rate of the throat at the design point by 1.15% and the increase of the total pressure recovery coefficient by 6.73%. The self-starting Mach number of the inlet decreases from 4.6 to 3.2, which indicates that the self-starting ability is improved significantly by the three-slot combination scheme. In order to illustrate the role of each slot in improving the self-starting ability, three two-slot combination schemes, which are called Case 3, Case 4, and Case 5, are set up by closing Slot 1, Slot 2, and Slot 3 in turn and their self-starting processes are simulated. The results indicate that the self-starting Mach numbers of Case 3, Case 4, and Case 5 are 3.6, 4.1, and 4.5 respectively, which are 0.4, 0.9, and 1.3 higher than that of Case 2 respectively. Slot 3 has the greatest influence on the self-starting ability. When the incoming Mach number rises to 4.2, a closed separation zone is induced between Slot 2 and the throat by the reflected shock wave on the cowl side of Case 5. Due to the lack of lip overflow, which is an important flow regulation mechanism, the separation zone has a strong self-sustaining ability, and the inlet keeps unstart until the incoming Mach number rises to 4.5. In addition, in the absence of Slot 1 or Slot 2, the large-scale separation zone will not disappear until the incoming flow pressure increases to a certain value.

A hybrid a posteriori MOOD limited lattice Boltzmann method to solve compressible fluid flows – LBMOOD

In this paper we blend two lattice-Boltzmann (LB) numerical schemes with an a posteriori Multi-dimensional Optimal Order Detection (MOOD) paradigm to solve hyperbolic systems of conservation laws in 1D and 2D. The first LB scheme is robust to the presence of shock waves but lacks accuracy on smooth flows. The second one has a second-order of accuracy but develops non-physical oscillations when solving steep gradients. The MOOD paradigm produces a hybrid LB scheme via smooth and positivity detectors allowing to gather the best properties of the two LB methods within one scheme. Indeed, the resulting scheme presents second order of accuracy on smooth solutions, essentially non-oscillatory behavior on irregular ones, and, an ‘almost fail-safe’ property concerning positivity issues. The numerical results on a set of sanity test cases and demanding ones are presented assessing the appropriate behavior of the hybrid LBMOOD scheme in 1D and 2D.

The rebound law of micro-particle on amorphous alloys under high impact velocities

Compared to their crystalline counterparts, amorphous alloys due to disordered structures are expected to have higher elasticity of deformation. However, in this work, we use the micro-ballistic impact technique to show a smaller dynamic redound of micro-particles on a Zr-based amorphous alloy than that on its corresponding polycrystalline target. We find that the two alloys follow the same rebound law of micro-particle under low impact velocities, but with increasing impact velocity the amorphous alloy exhibits a faster decrease in rebound velocity of micro-particle. This lower rebound results from the easier activations of shear banding in glassy structures, thus contributing to more significant energy dissipation during the micro-particle impact. Further analyses imply that the amorphous alloys and their crystalline counterparts are more favorable in shock wave and projectile protection, respectively. This work is useful in the understanding of the dynamic elasticity and shock energy dissipation of amorphous alloys under micro-particle impacts.

Effects of Connecting Structures in Double-Hulled Water-Filled Cylindrical Shells on Shock Wave Propagation and the Structural Response to Underwater Explosion

In conventional double-hulled submarines, the connecting structures that facilitate the linkage between the two hulls are crucial for load transmission. This paper aims to elucidate the effect of these connecting structures on resistance to shock waves generated by underwater explosions. Firstly, a self-developed numerical solver is built for the one-dimensional water-filled elastically connected double-layer plate model. The shock wave propagation characteristics, shock response of structure, water cavitation, and impact loads transmitted through the gap water and the connecting structures are analyzed quantitatively. The results reveal that the majority of the shock impulse is transmitted by the gap water if the equivalent stiffness of the connecting structures is much less than that of the gap water. Then, a three-dimensional model of the double-hulled, water-filled cylindrical shell is constructed in Abaqus/Explicit, utilizing the acoustic-structural coupling methodology. The analysis focuses on the influence of the thickness and density distribution of the connecting structures on the system’s shock response. The results indicate that a densely arranged connecting structure results in a wavy deformation of the outer hull and a notable reduction in both the impact response and strain energy of the inner hull. When the stiffness of the densely arranged connecting structure is comparatively low, the internal energy and plastic energy of the inner hull are decreased by 16.5% and 24.1%, respectively. The findings of this research are useful for assessing shock resistance and for the design of connecting structures within conventional double-hulled submarines.

Revolutionising Skincare Through Airtificial Intelligence

Abstract: Background: Over the last 10years there has been a drastic shift in the development of computer-based systems, artificial intelligence, algorithms and technology in the world of dermatology be it cosmetic or even retail production of products sold to customers with high-tech technology and innovative means to build their client base through customer delight. Artificial Intelligence is particularly helpful in recognizing the type of skin customers have and suggesting solutions which help customers pick from the range of options given to them. Most e-commerce platforms have begun using such AI driven soft wear to help customers while they are in the comfort of their homes to choose from a range of cosmetic options right from lipsticks, concealers, foundation, eyeshadows, shades of tins, serums etc. Given that every person has a different skin type, these applications ensure 100 percent personalized suggestions. This new trend is sending shock waves across the retail sector around the world attracting a massive customer base to adapting to AI Derma logy and retail. The intelligent software used by sever companies not only benefits the customer, but also helps companies with their operational efficiency as they can use AI algorithms to predict and forecast the inventory to help reduce over production and excessive stock production minimizing product wastage and improving sustainably.AI is booming in both clinical diagnosis as well as giant companies such as Loreal and Olay who are dedicated to providing customers with advanced tools like skin analyzers or apps based on predefined rules which help AI-powered tools analyze skin conditions, age, and personal skincare history to provide highly personalized product recommendations. In clinical diagnosis AI offers valuable insight to the patient’s skin and condition be it cancer or other skin diseases making judgments to assist the doctors and dermatologist in making informed decisions regarding the line of treatment for the patient in question. This includes screening, diagnosis, treatments and predictions of the treatment outcomes. These new innovative and robust AI systems leaving customers feeling confident and have not begun relying on AI driven treatments and procedures

Effectiveness of Non-Pharmacological Interventions for Spasticity Management in Multiple Sclerosis: A Systematic Review.

This systematic review aims to determine the effectiveness of non-pharmacological interventions for the management of spasticity in people with multiple sclerosis (pwMS). A comprehensive literature search in health science databases (MEDLINE, Embase, CENTRAL, CINHAL) was performed to identify randomized controlled trials (RCTs) (up to April 2024). Manual searching in journals and screening of the reference lists of identified studies were conducted. Two authors independently selected the studies, assessed the methodological quality, and summarized the evidence. A meta-analysis was not feasible due to the methodological, clinical, and statistical diversity of the included studies. Overall, 32 RCTs (n=1,481 participants) investigated various types of non-pharmacological interventions including: physical activity, transcranial magnetic stimulation (intermittent theta burst stimulation [iTBS], repetitive transcranial magnetic stimulation [rTMS]), electromagnetic therapy, transcutaneous electrical nerve stimulation, vibration therapy, shock wave therapy, self-management educational programs, and acupuncture. All studies scored 'low' on the methodological quality assessment, implying a high risk of bias. The findings suggest 'moderate to low certainty' evidence for physical activity programs used in isolation or combination with other interventions (pharmacological or non-pharmacological), and for iTBS/rTMS with or without adjuvant exercise therapy in improving spasticity in adults with MS. There is 'very low certainty' evidence supporting the use of other modalities for treating spasticity in this population. Despite a wide range of non-pharmacological interventions used for the management of spasticity in pwMS, there is a lack of conclusive evidence for many. More robust trials with larger sample sizes and longer-term follow-ups are needed to build evidence for these interventions.

Are Extracorporeal Shock Waves Just a Therapeutic Tool?

Background: Focused extracorporeal shock wave therapy (ESWT) has been successfully used to treat musculoskeletal conditions, but ESWT stimulates nociceptors, causing pain deep in the tissue during treatment. The occurrence of pain during ESWT is a side effect, but it can help identify painful sites and assess minimum (MiTI) and maximum (MaTI) pain thresholds to ESWT pressure stimuli. This topic has received limited attention in literature. Methods: This observational study describes a specific approach to using ESWT to study pain in 71 patients. The approach proposes moving the ESWT transducer head of the device over the entire joint surface, progressively increasing the energy level until the patient experiences pain. Results: In the study, MiTI and MaTI were 0.218 ± 0.090 and 0.416 ± 0.165 mJ/mm2 in the affected joint and 0.282 ± 0.128 and 0.501 ± 0.174 mJ/mm2 in the contralateral homologous healthy joint, being significantly lower in the affected joint (MiTI: p &lt; 0.001 and MaTI: p = 0.003, respectively). ESWT induced pain in 94.37% of the sites with the highest subjective pain and in a greater number of sites (204) than digital pressure (123) (p &lt; 0.001). All sites with digital pressure pain also had ESWT pain. Conclusions: These results suggest that the ESWT device may be useful in investigating pain in musculoskeletal conditions and tailoring therapy.

Double-pulse laser peening as a surface enhancement technology

In this paper, we discuss double-pulse laser peening (DPLP) as surface enhancement technology. Although single-pulse laser peening (SPLP) has yielded excellent results across various applications, its processing performance and efficiency are limited. The DPLP technique involves two laser pulses with a controlled irradiation interval and intensity, enhancing laser absorption through the plasma plume and generating high-amplitude laser-induced shock waves. This study involved conducting DPLP experiments on stainless steel, comparing the outcomes with those of conventional SPLP to assess DPLP’s functionality. After the initial prepulse irradiation, the subsequent main pulse was timed and irradiated onto the stainless steel. We evaluated the surface hardness to ascertain the impact of laser peening. The findings indicated that the surface hardness achieved with DPLP was up to 64% greater than that with SPLP. Additionally, the surface hardness achieved through DPLP depended on the delay time between the pulses and the intensity of the initial prepulse. These findings suggest that DPLP can significantly enhance surface hardness, providing a potential pathway for improving material performance in various industrial applications. Furthermore, simulation experiments of DPLP were performed using a one-dimensional simulation code that calculates the laser-matter interaction during the peening process. The pressure profiles generated by the simulation closely matched the experimentally derived hardness profiles, confirming the simulation’s ability to predict the mechanical effects induced by DPLP on the target sample and assist in further optimization of the DPLP process.

Numerical Solution of Burgers Equation Using Finite Difference Methods: Analysis of Shock Waves in Aircraft Dynamics

In this research, the Lax, the Upwind, and the MacCormack finite difference methods are applied to the experimental solving of the one-dimensional (1D) unsteady Burger's Equation, a Hyperbolic Partial Differential Equation. These three numerical analysis-solving methods are implemented for accurate modeling of shock wave behavior high-speed flows that are necessary for aerospace engineering design. This research analysis proves that the MacCormack technique is the one that treats the differential equations with second-order accuracy. This method is quite preferred when it comes to numerical simulations because of its advanced level of accuracy. Although the Upwind and Lax methods are slightly less accurate, they show the development of shock waves that give visualizations to better understand the flow dynamics. Also, in this study, the impact of varying viscosity coefficients on fluid flow characteristics by using the lax (a numerical method for solving the viscous Burgers equation) is investigated. This identification of the phenomenon sheds light on the behavior of boundary layers, which, in turn, can be used to improve the design of high-speed vehicles and lead to a greater understanding of the area of ​​fluid dynamics.

Vulnerability Assessment for Naval Ships against Air-Explosive Impulses: Modified Damage-Extent Method Incorporating Structural Capacity

Abstract This study introduces an enhanced damage-extent method that incorporates the structural load-bearing capacity of the hull to assess the vulnerability of naval ships to explosive loads. This vulnerability assessment predicts the area of damage to the hull structure and calculates the probability of onboard equipment experiencing functional losses due to the explosive load, thus allowing various design alternatives to be evaluated. The proposed methodology improves upon traditional damage-volume-based approaches, such as damage-radius and ellipsoid methods, by considering the hull's structural stiffness and intrinsic damage resistance. It integrates the hull's structural resistance to the load, enhancing the damage assessment process for both the hull and equipment. This approach facilitates damage prediction for different hull designs by comparing the allowable impulse with the explosive pressure. In assessing the functionality loss and vulnerability of the equipment within the damaged hull, the network of equipment functions is considered. An anti-ship cruise missile with a sea-skimming trajectory is investigated as the explosive charge, with procedures established to simulate its trajectory and impact location on the hull. Hundreds of potential internal and external explosion points are generated, predicting the explosive pressure at each location. The shock wave, including incident overpressure, reflection pressure, and quasi-static gas pressure, is converted into impulses, taking into account the configuration of hull compartments to accurately predict these pressures and equivalent impulse. The resulting impulse is compared with the intrinsic damage capacity of each compartment's structure to assess potential damage. System network and fault tree analysis evaluate the loss of function and vulnerability of equipment within the damaged hull. Finally, the proposed capacity-based damage extent method demonstrates more accurate damage assessment compared to traditional methods, overcoming the limitations of damage-radius and ellipsoid approaches by considering hull strength

Focused shock wave and ultrasound therapies in the treatment of lateral epicondylitis - a randomized control trial

Persistent symptoms of lateral epicondylitis prompt patients to seek effective conservative treatment. The study aimed to determine the effects of focused shock wave (FSWT) and ultrasound therapies for lateral epicondylitis. Sixty patients with tennis elbow were randomly divided into three equal groups: A, B, and C. Group A received a total of 3 FSWT sessions, with 7 days between treatments; Group B received ultrasound therapy in 10 sessions over 2 weeks, while patients in Group C were treated with placebo ultrasound. All patients were also given deep friction massage. Before the start of therapy, and at 1, 3, 6, and 12 weeks after its completion, pain intensity and function of the affected upper limb were assessed in all patients. Wrist extensor and flexor strength and grip strength were measured in the affected and unaffected limb. Significant reductions in pain and significant improvements in the function of the affected limb compared to baseline values were observed in all study groups at 6 and 12 weeks after the completion of therapy. Analysis of percentage changes in these variables showed significant differences between Groups A and B in favor of Group A. The strength of wrist extensors and grip strength of the affected limb at 6 and 12 weeks after treatment completion was significantly higher in Groups A and B compared to pre-therapy values. However, there were no statistically significant differences between the groups regarding percentage changes in muscle strength in the affected limb. Pain reduction and function improvement in patients with lateral epicondylitis were significantly greater after FSWT (0.2 mJ/mm2 / 4 Hz / 2000 shocks) than after sonotherapy (3 MHz / 0.5 W/cm2 / 20%). Increases in wrist extensor strength and grip strength of the affected limb were comparable after both therapies. Given the greater therapeutic effect in the subjective evaluation, we recommend a combination therapy of FSWT with deep friction massage.Trial registration The trial was prospectively registered in the ISRCTN registry (no. ISRCTN11907358 registration date 30.07.2020).

Think Tank 2: How Do We Precisely Define the "High Risk Bladder" and What Are the Interrelationships Between Inflammation, Blood Flow, Fibrosis, and Loss of Bladder Compliance?

Defining "high-risk bladder" or "high-pressure bladder" involves recognizing the potential for an unsafe lower urinary tract, where dysfunction in storage and micturition can threaten upper urinary tract health, leading to unfavorable outcomes like dialysis, recurrent infections, systemic impact, or mortality. ICI-RS was held in Bristol in June 2024, and Think Tank 2 aimed to define research priorities including identifying clinical predictors and developing prevention and monitoring strategies. Risk factors encompass both congenital and neurogenic lower urinary tract dysfunction, bladder outlet obstruction, vascular diseases, and inflammatory disorders, but a validated stratification risk is lacking. Reduced compliance and detrusor overactivity lead to high filling pressures and raised detrusor leak point pressure, playing urodynamic studies a crucial role in risk assessment, though further research is needed for different neurogenic populations. Congenital conditions such as spina bifida, posterior urethral valves, and bladder exstrophy also contribute to a high-risk bladder through fibrosis and reduced compliance. Inflammation and ischemia are key factors, with inflammation leading to fibrosis and impaired bladder storage and voiding function. Novel treatments, including sGC activators, PDE5 inhibitors, and regenerative therapies like stem cell injections and extracorporeal shock wave treatment, show promise in mitigating fibrosis and improving bladder compliance. Identifying and validating clinical risk stratification models, precise biomarkers and therapeutic windows remains essential for effective management and reversal of bladder fibrosis and dysfunction.

RIRS with FV-UAS vs. ESWL for the management of 1–2 cm lower pole renal calculi in obese patients: a prospective study

ObjectiveTo evaluate the efficacy and safety of retrograde intrarenal surgery (RIRS) combined with flexible vacuum-assisted ureteral access sheath (FV-UAS) versus extracorporeal shock wave lithotripsy (ESWL) for the management of 1–2 cm lower pole renal calculi (LPC) in obese patients.Patients and methodsThis prospective, randomized study included 149 obese patients with 1–2 cm LPC. Patients were allocated into two groups: 76 patients underwent RIRS with FV-UAS, and 73 patients received ESWL. The parameters assessed included stone-free rate (SFR), retreatment rate, complications, operative time, and pain intensity measured by the visual analog scale (VAS). Stone-free status was defined as the absence of stones on computed tomography or residual fragments smaller than 4 mm at 4 weeks post-procedure.ResultsThe baseline characteristics of the two groups were comparable. The SFR was significantly higher in the RIRS group, reaching 86.8%, compared to 63.0% in the ESWL group (p = 0.034). Furthermore, the retreatment rate was significantly lower in the RIRS group, at 5.2%, versus 24.7% in the ESWL group (p &amp;lt; 0.001). The average operative time for RIRS was notably longer, at 65.3 ± 6.4 min, compared to 25.3 ± 7.8 min for ESWL (p &amp;lt; 0.001). The complication rates were 9.2% for the RIRS group and 6.8% for the ESWL group, with no statistically significant difference (p = 0.326). All complications were classified as Grade I or II according to the modified Clavien classification system. No significant differences were observed between the two groups regarding pain VAS scores and the composition of the stones.ConclusionRIRS with FV-UAS demonstrated superior efficacy, evidenced by a higher SFR and reduced retreatment rates compared to ESWL, despite a longer operative duration. Both treatment modalities showed comparable safety profiles. RIRS with FV-UAS emerges as a viable, effective, and reproducible intervention for managing 1–2 cm LPC in obese patients, providing significant clinical advantages.