- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Hounsfield units-a significant predictor of lasering time and energy in the management of upper urinary tract stones using Holmium: Yttriuma??Aluminum Garnet lasers
摘要： Purpose To study the impact of stone density as assessed by Hounsfield units (HU) on total laser energy (TLE) used and total laser time (TLT) spent in complete fragmentation of upper urinary tract stones. In addition, we also studied the impact of stone composition on the laser energy and time required for fragmentation. Methods Thirty consecutive patients fulfilling inclusion and exclusion criteria were included in the study. Patients with renal or proximal ureteral stones with a size of 5–20?mm were included. Stone fragmentation was performed using Ho:YAG 100?W laser and TLT and TLE were correlated with the HU and stone composition. Results The mean stone diameter was 10.83 ± 3.5?mm and the mean HU was 893 ± 315. The mean TLE and TLT were 8.86 ± 3.12?kJ and 18.46 ± 6.9?min, respectively. We observed a strong positive correlation between HU and TLE (r = 0.84, p value < 0.001) and between HU and TLT (r = 0.58, p value = 0.001). However, the stone composition did not influence the lasering energy (p value = 0.36) and lasering time (p value = 0.30). Stone diameter also had significant positive correlation with TLE (r = 0.41; p = 0.02) and TLT (r = 0.54; p? 0.002). When controlling for stone size the correlation of HU with TLE (r = 0.83; p < 0.001) and TLT (r = 0.52; p = 0.004) remained significant. Conclusions HU and stone diameter are significant predictors of TLE and TLT when using Ho:YAG laser for stone fragmentation. However, stone composition and stone location failed to show any significant effect on either of these parameters.
关键词： Urolithiasis,Energy,fURS,RIRS,Laser,Holmium YAG
更新于2025-09-23 15:19:57
-
Characteristics of Bubble Oscillations During Lasera??Activated Irrigation of Root Canals and Method of Improvement
摘要： Background and Objectives: Laser‐activated irrigation of dental root canals is being increasingly used as its efficacy has been shown to be superior compared with conventional techniques. The method is based on laser‐initiated localized fluid evaporation and subsequent rapid bubble expansions and collapses, inducing microfluid flow throughout the entire volume of the cavity. The irrigation efficacy can be further improved if optimally delayed “SWEEPS” double laser pulses are delivered into the canal. This study aims to show that the irrigation efficacy, as measured by the induced pressure within the canal, is related to the double pulse delay, with the maximal pressure generated at an optimal delay. The second aim is to find a method of determining the optimal delay for different cavity dimensions and/or laser parameters. Study Design/Materials and Methods: Experiments were made in transparent models of root canals where Er:YAG laser (λ = 2.94 μm, pulse duration tp = 25 or 50 microseconds, and pulse energies up to EL = 40 mJ) was used with a combination of cylindrical and conical fiber‐tip geometries (diameters 400 and 600 μm). High‐speed photography (60,000 fps) and average pressure measurements inside the canal were used for process characterization. Results: The results show that a pressure amplification of more than 1.5 times occurs if the laser pulse delay approximately coincides with the bubble oscillation time. Correlations between normalized oscillation time and canal diameter for a wide range of laser pulse energies (R2 = 0.96) and between the average pressure within the canal and the bubble oscillation periods (R2 = 0.90) were found. A relationship between the bubble oscillation time and the diameter of the treated cavity was found depending on the bubble oscillation time in an infinite fluid reservoir. Conclusions: The bubble oscillation time within a constrained volume can be determined based on the known oscillation time in infinite space, which offers a fast and simple solution for optimization of the laser parameters. These findings enable determination of optimal conditions for shock wave generation, and improvement of root canal irrigation at the same dose of laser energy input, leading to improved treatment efficacy and safety.
关键词： constrained environments,cavitation bubble,irrigation,Er:YAG laser,root canals,laser‐activated,laser‐induced cavitation
更新于2025-09-23 15:19:57
-
Clinical efficacy comparison of low-temperature plasma radiofrequency ablation and Nd:YAG laser in treating recurrent acquired nasolacrimal duct obstruction
摘要： To evaluate the effectiveness and safety of low-temperature plasma radiofrequency ablation (coblation) and Nd:YAG laser in treating recurrent nasolacrimal duct obstruction. A prospective study was performed on patients who agreed to be treated with coblation or Nd:YAG laser for recurrent nasolacrimal duct obstruction after failed lacrimal Nd:YAG laser combined with silicone intubation. The visual analogue scale (VAS) pain grade was assessed at baseline, immediately, and 3 and 7 days after surgery. The degree of watering, lacrimal passage irrigation, and complications were also evaluated 1 week and 1, 3, and 6 months after surgery. Ninety-five patients who met the criteria for recurrent nasolacrimal duct obstruction from February 2018 to February 2019 were included in this study, with 46 patients receiving coblation and 49 patients Nd:YAG laser. The intraoperative and postoperative (3 days after surgery) VAS pain grades of the patients who received coblation were significantly lower than those who received Nd:YAG laser (P < 0.001). The number of patients in the coblation group who achieved complete clinical relief (no epiphora symptoms with fluent lacrimal passage irrigation) was significantly larger than that in the lacrimal Nd:YAG laser group at 1, 3, and 6 months after surgery (P = 0.033, P = 0.006, P = 0.003, respectively). During the follow-up period, there were no unexpected complications in either group. Compared with Nd:YAG laser, coblation performed well in alleviating pain and maintaining sustained disease relief and may therefore be an alternative to conventional laser or dacryocystorhinostomy surgery in the management of recurrent nasolacrimal duct obstruction.
关键词： Nd:YAG laser,Recurrent acquired nasolacrimal duct obstruction,Low-temperature plasma radiofrequency ablation,VAS pain grade
更新于2025-09-23 15:19:57
-
Treating Vaginal Laxity Using Nonablative Er:YAG Laser: A Retrospective Case Series of Patients From 2.5??Years of Clinical Practice
摘要： Introduction: Vaginal laxity drastically impairs women’s quality of life, suggesting there is a need for effective noninvasive treatments. Aim: The aim was to retrospectively assess the effectiveness and safety of a nonablative Er:YAG IntimaLase laser procedure for vaginal laxity in patients treated in our clinical practice during a 2.5-year period. Methods: Laser treatment for vaginal laxity was performed using an intravaginal nonablative Er:YAG laser. Effectiveness was assessed using a Patient Satisfaction Questionnaire and also by independent evaluation of before and after treatment photographs of the patients’ introitus. The safety and tolerability of the procedure was monitored in all patients. Main Outcome Measure: The study showed an improvement of sexual grati?cation and improvement of vaginal tightness, as assessed by patients. The tightness of the introitus was also improved, as assessed by independent evaluators. Results: As assessed by the Patient Satisfaction Questionnaire, we show that 92.7% of patients experienced improvement of sexual grati?cation after IntimaLase laser treatment. The results of the visual evaluation of the grade of laxity improvement in the introitus area, when open introitus photos were evaluated, show that 69% (n ? 20/29) of patients had an improvement of laxity. Nonablative Er:YAG treatment seems to be an effective and safe treatment for vaginal laxity. As it is a noninvasive procedure, it should be considered before any vaginoplasty surgery. The study included all the patients treated in clinical practice and observed very few adverse effects. The results were comparable with other published data. Because it is a retrospective study, there is a lack of a control group. Conclusion: The results have con?rmed that patients suffering from vaginal laxity can be effectively treated using the nonablative Er:YAG IntimaLase procedure without adverse effects.
关键词： Vaginal Laxity,Sexual Grati?cation,Quality of Life,ER:YAG Laser
更新于2025-09-23 15:19:57
-
Multiple miliary osteoma cutis treatment response to Q-switched Nd:YAG laser: A case report
摘要： Facial multiple miliary osteoma cutis is a variant of osteoma cutis usually occurring in women with a previous history of acne vulgaris. Successful ablative laser treatment has been reported using both CO2 and Er:YAG lasers among other invasive treatment modalities, like surgical removal. We report a patient with biopsy-proven facial multiple miliary osteoma cutis responding to non-ablative Q-switched Nd:YAG laser therapy. The patient had excellent cosmesis without textural changes or hypopigmentation despite her Asian background after three sessions over 6 months. Multiple miliary osteoma cutis is therefore now amenable to non-surgical non-ablative therapy by using Q-switched Nd:YAG laser therapy reducing the risk of textural changes and hypopigmentation, especially in dark complexion and high-risk individuals. To our knowledge, this treatment approach has not been previously reported.
关键词： non-ablative,laser,acne,Osteoma cutis,Nd:YAG,bone,skin,therapy
更新于2025-09-23 15:19:57
-
Er:YAG laser cleaning of a marble Roman urn
摘要： There are very few documented instances of the use of an Er:YAG laser in the cleaning of stone artefacts; however, the cases reported in the literature have shown its effectiveness in the removal of surface organic patinas and lichens. A Roman marble funerary urn (67–100 AD) of archaeological importance was covered with an intractable surface layer that obscured its delicate decorative carving. Chromatographic mass spectrometric and Raman spectroscopic techniques allowed the characterisation of those inorganic and organic materials that had undergone photo-oxidation and biological changes, resulting in the thick encrustation. An Er:YAG laser at 2940nm, with a pulse length of 300μsec, was used for cleaning the urn. Preliminary tests were performed with fluences ranging from 0.7 to 6.4J/cm2 and in the presence of a variety of wetting agents. The laser cleaning resulted in a sufficiently clean marble surface with the thick deposit of unwanted material removed. Finally, the sensitivity of the method allowed for a compact layer of calcium oxalate to be retained on the marble’s surface to help protect it.
关键词： Er:YAG,cultural heritage,wetting auxiliary agent,laser cleaning,calcium oxalate,marble
更新于2025-09-23 15:19:57
-
A study on the heat distribution and oxidative modification of aged dammar films upon Er:YAG laser irradiation
摘要： This work shows the impact of one Er:YAG laser pulse to both the surface and bulk of aged dammar varnishes. Tests were performed in fluences ranging from 0.56 to 2.4J/cm2 and pulse durations of 100 and 300μs. Temperature changes upon irradiation were examined by (a) live recordings with an infrared thermal camera, and (b) determining the optical properties of the varnish, which allowed for estimates of the linear absorption coefficient and the temperature rise associated with the laser irradiation. Transmission and Fourier Transform Infrared (FTIR) spectroscopy studies captured increased energy transmissions through varnish films, as well as registering a reduction of hydroxides and carbon–hydrogen bonding as a function of fluence, respectively. FTIR and Differential Scanning Calorimetry (DSC) experimentally determined the absorption coefficient and the specific heat capacity of dammar films, and an overview of laser spots was carried out with Scanning Electron Microscopy (SEM). Evidence on the varnish response to Er:YAG laser irradiation is provided.
关键词： Er:YAG lasers,transmission,thermal effects,dammar varnish,analysis,modelling
更新于2025-09-23 15:19:57
-
Laser Annealing Enhanced the Photophysical Performance of Pt/n-PSi/ZnO/Pt-Based Photodetectors
摘要： Herein, the effect of pulsed Nd:YAG laser irradiation at different fluencies in air at room temperature on the performance of n-PSi/ZnO-based UV MSM photodetector was demonstrated. Thermal and photon energies were coupled to synthesize n-PSi/ZnO NCs heterojunctions. The porous silicon (PSi) films with nano-sized pore arrays were first prepared via photoelectrochemical etching (PECE) of n-type silicon wafers with 45 mA/cm2 current density for a duration of 30 min. This was followed by radio frequency sputtering (RFS) of ZnO on PSi at 700 oC and irradiating with a Nd: YAG laser pulses with laser fluence of 40 mJ/cm2. X-ray diffraction analysis indicates the formation of ZnO wurtzite hexagonal crystal structure of n-PSi/ZnO NCs, where the crystallite size decreases (96-29 nm) with number of pulses. Field emission electron scanning microscopy and atomic force microscopy reveal porous nanostructure, arrays of nearly spherically shape particles homogeneously distributed on the entire surface where roughness increases (84-139 nm) with number of pulses. Photoluminescence spectroscopy reveals intrinsic band-to-band transition, donor-acceptor pair emission and quenching of the broadband intensity related to improved of crystallinity, meanwhile the band gap energy of the n-PSi/ZnO NCs is found to decrease (3.26 – 3.13 V). The Nd:YAG laser annealing demonstrate a positive effect on the properties of n-PSi/ZnO NCs photodetector, exhibiting very high sensitivity (3772.92) and very short rise and recovery times (0.30 s and 0.26 s).
关键词： Porous silicon,n-PSi/ZnO junction,Nd-YAG laser,photodetectors
更新于2025-09-23 15:19:57
-
Simultaneous solar laser emissions from three Nd:YAG rods within a single pump cavity
摘要： We report here, to the best of our knowledge, the first simultaneous emission of three continuous-wave solar laser beams by end-side-pumping three 3.0 mm diameter, 25 mm length Nd:YAG single-crystal rods within a single conical pump cavity. An aspheric fused silica lens was used to couple the concentrated solar radiation from the focal zone of a parabolic mirror with 1.0 m2 effective collection area into the laser rods within the pump cavity. 18.3 W multimode solar laser power was measured, resulting in 5.1% laser slope efficiency. 0.036 W laser beam brightness figure of merit was also achieved for each beam, being 9 times more than that of the most efficient solar laser with 32.5 W/m2 collection efficiency. Since the three laser rods were associated with their own 1064 nm output mirrors, it was possible to adjust individually both solar laser output power levels and beam qualities of the three laser beams by adopting different resonant cavity lengths, enabling potential solar laser applications.
关键词： Laser emission,Multi-rod,Parabolic mirror,Slope efficiency,Solar-pumped laser,Nd:YAG
更新于2025-09-23 15:19:57
-
OPTIMIZED DISTANCE FOR NON-DAMAGING IN LASER CLEANING PREPARATION
摘要： Laser Technology has wide application in industry as well as in scientific research. Semiconductor industry also interested to use laser for cleaning contaminant. However, until today, no laser has been deployed to take over the traditional method due to lack of intension on it. As a first step to embark into industrial solution, initiative has been carried out to do fundamental experiment. Optimization has been established to find out the best position for cleaning without associated with damage. A Q-switched Nd:YAG laser was focused to create breakdown in the air. This is an indicator for plasma formation and shock wave generation as the main mechanisms of damage. Pure aluminium was used as a substrate and mounted on précised a 3D linear translational stage. The defocused distance was varied in the range of 0-25 mm. The damage image was recorded and analysed via the aid of ImageJ software. Small and deep dense deformation was observed as the target located at the focal point. As the defocused distance move further away, the damage tend to be eliminated and its depth approaching the same level as original.
关键词： breakdown,optimization,Damage,Nd:YAG laser,depth,distance
更新于2025-09-23 15:19:57