Search

Background Aims Methods Conclusions Androgenetic alopecia (AGA) is a prevalent form of hair loss that affects both men and women, severely impacting patients' quality of life. Traditional treatments include oral medications, topical medications, and hair transplantation, but these methods have certain side effects and limitations. How to safely effectively and maximally promote hair growth has been a key issue in the treatment of AGA. In recent years, fractionated laser therapy, as a noninvasive method, has gradually gained attention due to its minimally invasive and highly effective nature.In this paper, we summarized the studies related to fractional laser treatment of AGA in the past 15 years, and discussed its therapeutic mechanism, clinical effect, future development direction, and advantages and disadvantages compared with traditional treatment methods in the treatment of AGA.An extensive literature search was conducted using PubMed, Google, Google Scholar, Embase, and Scopus. All available articles studying fractional laser treatment of AGA were compiled in March 2024. Titles and abstracts were then screened for relevance and thoroughly examined for patient clinical outcomes. Prospective clinical trials, retrospective chart reviews, case series, and individual case reports were included in the literature review.Fractional laser treatment of AGA showed remarkable efficacy and high safety. Compared with traditional treatments, fractional laser has the advantages of minimally invasive, quick recovery, fewer side effects, and a wide range of population applicability, providing an effective treatment option for AGA patients. Further large‐scale clinical studies will help optimize the laser parameters and treatment settings to improve the therapeutic effect. [ABSTRACT FROM AUTHOR]

In recent years, essential oils (EOs) have received increased attention from the research community, and the EOs of cinnamon, patchouli, and geranium have become highly recognized for their antibacterial, antifungal, antiviral, and antioxidant effects. Due to these properties, they have become valuable and promising candidates for addressing the worldwide threat of antimicrobial resistance and other diseases. Simultaneously, studies have revealed promising new results regarding the effects of physical fields (magnetic and electric) and LASER (MEL) exposure on seed germination, plant growth, biomass accumulation, and the yield and composition of EOs. In this frame, the present study aims to investigate the influence of MEL treatments on cinnamon, patchouli, and geranium EOs, by specifically examining their composition, antimicrobial properties, and antioxidant activities. Results showed that the magnetic influence has improved the potency of patchouli EO against L. monocytogenes, S. enteritidis, and P. aeruginosa, while the antimicrobial activity of cinnamon EO against L. monocytogenes was enhanced by the electric and laser treatments. All exposures have increased the antifungal effect of geranium EO against C. albicans. The antioxidant activity was not modified by any of the treatments. These findings could potentially pave the way for a deeper understanding of the efficiency, the mechanisms of action, and the utilization of EOs, offering new insights for further exploration and application. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effects of combining a Pilates program with photobiomodulation therapy (PBMT) in patients with chronic nonspecific low back pain (CNLBP). Methods: Thirty-eight adults with CNLBP were randomly assigned to two groups: Pilates exercise + active PBMT (PIL + PBMT) or Pilates exercise + sham PBMT (PIL + SHAM). Both groups performed an 8-week mat Pilates program and received PBMT on their lumbar muscles 10 min before and after each session. The following variables were assessed before and after intervention: peak pain intensity, postural balance (i.e., center of the pressure [A-COP], velocity anteroposterior [Vel AP], and velocity mediolateral [Vel ML]), perceived disability (i.e., Oswestry Disability Index [ODI] and Roland Morris Disability Questionnaire [RMDQ]), and pain-related fear of movement (i.e., Tampa Scale of Kinesiophobia [TSK], Fear Avoidance Beliefs Questionnaire [FABQ], and Pain Catastrophizing Scale [PCS]). Results: Postural balance variables showed no statistically significant differences (p > 0.05) across time or between groups. The groups showed similar (p < 0.05) reductions in peak pain intensity, ODI, RMDQ, and PCS scores, but no statistically significant difference (p > 0.05) in TSK and FABQ scores. Conclusion: The mat Pilates program reduced peak pain intensity, perceived disability, and pain catastrophizing in adults with CNLBP, but PBMT had no additional effect on these variables. Mat Pilates alone or combined with PBMT was not able to improve postural balance. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the current evidence comparing low level to high level laser therapy to reveal any superiorities in the treatment of musculoskeletal disorders. Methods: Five databases were searched till September 2022 to obtain relevant RCTs comparing high intensity and low-level laser therapies in the management of musculoskeletal disorders. Two authors assessed the methodological quality of the included studies using the Physiotherapy Evidence Database scale and meta-analysis was conducted for studies that showed homogeneity. Results: Twelve articles were included in this systematic review with a total population of 704 participants across various musculoskeletal pathologies including tennis elbow, carpal tunnel syndrome, chronic non-specific low back pain, knee arthritis, plantar fasciitis, and subacromial impingement. There were no statistical differences between the two interventions in pain, electrophysiological parameters, level of disability, quality of life, postural sway or pressure algometer, however, Low level laser therapy showed superiority in increasing grip strength compared to high intensity laser therapy while results were significant in favour of high intensity laser therapy regarding long head of biceps diameter and cross sectional area, supraspinatus thickness and echogenicity and acromio-humeral distance. Conclusion: The current literature suggests no superiority of both types of laser therapy in musculoskeletal disorders, however, more RCTs with larger sample size are required to reach a definitive conclusion regarding the superiority of either form of laser therapy in musculoskeletal disorders. [ABSTRACT FROM AUTHOR]

With the development of laser technology in the 1960s, a technique was developed to inject intradermal vaccines immediately after irradiating the skin with laser light to elicit an adjuvant effect, referred to as “laser adjuvant.” We have been investigating the mechanism of laser adjuvant in influenza mouse models using noninvasive continuous-wave (CW) near-infrared (NIR) light mainly at a wavelength of 1064 nm, and have shown that the production of reactive-oxygen-species (ROS) in the skin and mast cells in the skin tissue plays an important role in the laser adjuvant effect. The new wavelength of 1270 nm NIR light is characterized by its ability to elicit the same vaccine adjuvant effect as other wavelengths at a lower energy, and may be suitable for clinical applications. In this study, we investigated the physiological activity of CW1270 nm NIR light in mast cells, its biological activity on mouse skin, and the durability of the vaccine adjuvant effect in influenza vaccine mouse models. We show that irradiation of mast cells with 1270 nm NIR light produced ROS and ATP, and irradiation of isolated mitochondria also produced ATP. In mouse skin, the relative expression levels of chemokine mRNAs, such as Ccl2 and Ccl20, were increased by irradiation with 1270 and 1064 nm NIR light at minimum safe irradiance. However, the relative expression of Nfkb1 was increased at 1064 nm, but not at 1270 nm. Serum anti-influenza IgG antibody titers increased early after immunization with 1064 nm, whereas with 1270 nm, there was not only an early response of antibody production but also persistence of antibody titers over the medium- to long-term. Thus, to our knowledge, we show for the first time that 1270 nm NIR light induces ROS and ATP production in mitochondria as photoreceptors, initiating a cascade of laser adjuvant effects for intradermal vaccines. Additionally, we demonstrate that there are wavelength-specific variations in the mechanisms and effects of laser adjuvants. In conclusion, CW1270 nm NIR light is expected to be clinically applicable as a novel laser adjuvant that is equivalent or superior to 1064 nm NIR light, because it can be operated at low energy and has a wavelengthspecific adjuvant effect with medium- to long-lasting antibody titer. [ABSTRACT FROM AUTHOR]

Objective: To determine the effectiveness of picosecond KTP in reducing peri-ocular dark circles caused mainly by excessive pigmentation and to compare Picosecond KTP with Thulium laser ability in reducing the intensity and extent of peri-ocular dark circles. Materials and methods: This split-face prospective study included twelve women with periorbital dark circles (pigmented or mixed-pigmented type). The left lower eyelid was treated using the PicoHi machine (HIRONIC Ltd), a full beam Q-switched Nd-YAG provided by KTP crystal (523 nm) at settings of 0.3 J/cm2, 5 mm, 5 Hz, and 300 Ps. Whereas the right lower eyelid was treated using the Lavieen machine (WON TECH Co., Ltd), a fractional Thulium laser (1927 nm) at setting 1320 mJ/cm2, 30 × 15 mm, 1500 microseconds. Patients received a series of 3 treatment sessions, given at 4-week intervals. Results: The 532-nm full beam Q-switched KTP and fractional Thulium lasers were more likely to induce post-inflammatory hyperpigmentation rather than decrease the pigmentation. The risk is higher with a Q-switched KTP laser, which may be attributed to the skin tone of the participants. Nonetheless, some improvement in the pigmented type of PDCs, although not detected clinically, was documented by the VISIA software. Conclusion: No solid conclusion can be drawn from the results of the study. Picosecond KTP and Thulium lasers may have a role in reducing PDCs yet more studies should be performed in order to determine the exact impact these lasers have. [ABSTRACT FROM AUTHOR]

Aims: Endovenous microwave ablation (EMWA) is an endovenous thermoablation (EVTA) system to ablate incompetent truncal veins. Early results suggest that EMWA uses more power than endovenous laser ablation (EVLA) to get the same results. We aimed to define the parameters for EMWA, which give the same tissue ablation as EVLA, using the validated porcine liver model. Methods: EVLA (1470 nm 600 micron radial fibre) treatments were performed at 6 W, 8 W and 10 W, at pullback speeds of 6, 7, 8 and 9 s/cm, giving Linear Endovenous Energy Densities (LEEDs) between 36 - 90 J/cm. Each combination of power and pullback was repeated 5 times. We then used EMWA in the same model. Powers of 35-75 W and pullback speeds of 4-9 s/cm were used (LEEDs 140-675 J/cm). Ablation tracts from both devices were analysed by 2 blinded observers, noting thermal spread and carbonisation. Results: For each commonly used parameter for EVLA, we identified a range of parameters for EMWA that produced similar tissue ablation in the porcine liver model. To keep the pullback speeds within the usual range, powers of 35-75 W were needed with EMWA, with mean EMWA LEEDs 3.9 - 5.8 times higher than EVLA LEEDs. We found the quicker the pullback speed, the higher the multiple of EMWA LEED we needed to get the same effect. Conclusion: We have identified parameters for EMWA that gave equivalent tissue ablation in the porcine liver model to commonly used parameters used for EVLA. These need to be validated clinically, but as the model used has already been validated against clinical outcome in endovenous thermal ablation, there is little reason to suspect that these results would not be valid. As the power during EMWA is higher than EVLA, EVMA LEEDs are approximately 4-6 times higher than EVLA LEEDs to achieve the same thermal effect on the tissues. [ABSTRACT FROM AUTHOR]

For real-world applications, autonomous mobile robotic platforms must be capable of navigating safely in a multitude of different and dynamic environments with accurate and robust localization being a key prerequisite. To support further research in this domain, we present the INSANE datasets (Increased Number of Sensors for developing Advanced and Novel Estimators)—a collection of versatile Micro Aerial Vehicle (MAV) datasets for cross-environment localization. The datasets provide various scenarios with multiple stages of difficulty for localization methods. These scenarios range from trajectories in the controlled environment of an indoor motion capture facility, to experiments where the vehicle performs an outdoor maneuver and transitions into a building, requiring changes of sensor modalities, up to purely outdoor flight maneuvers in a challenging Mars analog environment to simulate scenarios which current and future Mars helicopters would need to perform. The presented work aims to provide data that reflects real-world scenarios and sensor effects. The extensive sensor suite includes various sensor categories, including multiple Inertial Measurement Units (IMUs) and cameras. Sensor data is made available as unprocessed measurements and each dataset provides highly accurate ground truth, including the outdoor experiments where a dual Real-Time Kinematic (RTK) Global Navigation Satellite System (GNSS) setup provides sub-degree and centimeter accuracy (1-sigma). The sensor suite also includes a dedicated high-rate IMU to capture all the vibration dynamics of the vehicle during flight to support research on novel machine learning-based sensor signal enhancement methods for improved localization. The datasets and post-processing tools are available at: https://sst.aau.at/cns/datasets/insane-dataset/ [ABSTRACT FROM AUTHOR]

This study addresses the challenge of measuring deposited film thickness during semiconductor manufacturing in real-time. Accordingly, we present the development of a sensor capable of measuring the deposition and growth thickness of wafers within a chamber in situ. Using a laser measurement instrument, we designed a sensor equipped with a light-receiving component to capture the reflected light signals. Our experimental results confirm the feasibility of real-time measurements; the oxide and nitride films are measured with a deviation of 10 nm or less and a minimum error factor as low as 0.68 %. This sensor is promising for improving the efficiency and accuracy of film thickness measurements in semiconductor manufacturing processes. [ABSTRACT FROM AUTHOR]

Monitoring the strain in the rotating flywheel in a kinetic energy storage system is important for safe operation and for the investigation of long-term effects in composite materials like carbon-fiber-reinforced plastics. An optoelectronic strain-measurement system for contactless deformation and position monitoring of a flywheel was investigated. The system consists of multiple optical sensors measuring the local relative in-plane displacement of the flywheel rotor. A special reflective pattern, which is necessary to interact with the sensors, was applied to the surface of the rotor. Combining the measurements from multiple sensors makes it possible to distinguish between the deformation and in-plane displacement of the flywheel. The sensor system was evaluated using a low-speed steel rotor for single-sensor performance investigation as well as a scaled-down high-speed rotor made from PVC plastic. The PVC rotor exhibits more deformation due to centrifugal stresses than a steel or aluminum rotor of the same dimensions, which allows experimental measurements at a smaller flywheel scale as well as a lower rotation speed. Deformation measurements were compared to expected deformation from calculations. The influence of sensor distance was investigated. Deformation and position measurements as well as derived imbalance measurements were demonstrated. [ABSTRACT FROM AUTHOR]

This article shows a novel, minimally invasive laser method for skin rejuvenation by creating isolated microscopic lesions within tissue below the epidermis using laser induced optical breakdown (LIOB). Using a well-researched technology, wavelengths of 1064/532nm focused near-infrared laser pulses are used to create optical breakdown in the dermis while leaving the epidermis unharmed, resulting in cavities due to plasma formation. This stimulates a wound healing response and leads to stimulation and neocollagenesis terminating in results of skin rejuvenation such as improvement of laxity, colour, and improvement in the appearance of pores. A retrospective trial with analysis of in-vivo, non-interventional treated human skin samples successfully showed the safety and effectiveness of the treatment; microscopic in LIOB and macroscopic in edema and erythema. Treatments can be performed by minimal to no downtime and mild to no side-effects with no topical anesthetics needed. The non-interventional in-vivo results shown by confocal laser microscopy (LC-OCT), showed evidence of microscopic cavities and new collagen formation around the vacuoles. Conclusion: This method is a safe and efficient alternative to more invasive procedures by minimal to no social downtime and mild to no side effects. [ABSTRACT FROM AUTHOR]

In the last two decades, the activation of root canal irrigants with pulsed lasers as an adjunct in root canal treatment has become increasingly popular. This narrative review explains the physical basics and the working mechanism of laser‐activated irrigation (LAI), explores the parameters influencing LAI efficacy, considers historical evolutions in the field and summarizes laboratory and clinical evidence with emphasis on the antimicrobial action of LAI. Cavitation is the driving force behind LAI, with growing and imploding vapour bubbles around the laser tip causing various secondary phenomena in the irrigant, leading to intense liquid dynamics throughout the underlying root canal. High‐speed imaging research has shown that laser wavelength, pulse energy, pulse length and fibre tip geometry are parameters that influence this cavitation process. Nevertheless, this has not resulted in standardized settings for LAI. Consequently, there is significant variability in studies assessing LAI efficacy, complicating the synthesis of results. Laboratory studies in extracted teeth suggest that, with regard to canal disinfection, LAI is superior to conventional irrigation and there is a trend of higher antimicrobial efficacy of LAI compared to ultrasonic activation. Clinical evidence is limited to trials demonstrating similar postoperative pain levels after LAI versus no activation or ultrasonic activation. Clinical evidence concerning the effect of LAI on healing of apical periodontitis as yet is scarce. [ABSTRACT FROM AUTHOR]

Digital Elevation Models (DEMs) are a necessity for modelling many large-scale environmental processes. In this study, we investigate the potential of data from two spaceborne lidar altimetry missions, ICESat-2 and GEDI—with respect to their vertical accuracies and planimetric data collection patterns—as sources for rasterisation towards creating global DEMs. We validate the terrain measurements of both missions against airborne lidar datasets over three areas in the Netherlands, Switzerland, and New Zealand and differentiate them using land-cover classes. For our experiments, we use five years of ICESat-2 ATL03 data and four years of GEDI L2A data for a total of 252 million measurements. The datasets are filtered using parameter flags provided by the higher-level products ICESat-2 ATL08 and GEDI L3A. For all areas and land-cover classes combined, ICESat-2 achieves a bias of −0.11 m, an MAE of 0.43 m, and an RMSE of 0.93 m. From our experiments, we find that GEDI is less accurate, with a bias of 0.09 m, an MAE of 0.98 m, and an RMSE of 2.96 m. Measurements in open land-cover classes, such as "Cropland" and "Grassland", result in the best accuracy for both missions. We also find that the slope of the terrain has a major influence on vertical accuracy, more so for GEDI than ICESat-2 because of its larger horizontal geolocation error. In contrast, we find little effect of either beam power or background solar radiation, nor do we find noticeable seasonal effects on accuracy. Furthermore, we investigate the spatial coverage of ICESat-2 and GEDI by deriving a DEM at different horizontal resolutions and latitudes. GEDI has higher spatial coverage than ICESat-2 at lower latitudes due to its beam pattern and lower inclination angle, and a derived DEM can achieve a resolution of 500 m. ICESat-2 only reaches a DEM resolution of 700 m at the equator, but it increases to almost 200 m at higher latitudes. When combined, a 500 m resolution lidar-based DEM can be achieved globally. Our results indicate that both ICESat-2 and GEDI enable accurate terrain measurements anywhere in the world. Especially in data-poor areas—such as the tropics—this has potential for new applications and insights. [ABSTRACT FROM AUTHOR]

Angiofibromas are a common facial manifestation of tuberous sclerosis (TS). However, current treatments have proven ineffective due to high recurrence rates and noncompliance. To address this issue, we developed a new triple laser therapy protocol for more effective management of angiofibromas. We conducted tests to validate its efficacy. This is a prospective study of 10 patients with TS (4 women and 6 men, mean age 26.3 years [15–37 years]) with angiofibromata who received triple sequential laser therapy at our private dermatological clinic conducted from January 2000 to December 2022. We evaluated the outcome with the Facial Angiofibromata Severity Index (FASI) via clinical photography (0, 6 months, 1 year, and 2 years), and Dermatology Life Quality Index (DLQI). All patients had a successful recovery without any complications. Among these 10 patients, 4 experienced localized recurrences at their 6-month follow-up. These recurrences were treated with a second single carbon dioxide laser session. After 2 years of follow-up, we observed no recurring facial cutaneous manifestations. Furthermore, all patients experienced a decrease in their FASI score after treatment. According to the Visual Analogue Scale, patients reported 95% satisfaction, and DLQI indicated only a minor impact on their everyday lives. We believe that this protocol of three-step laser treatment is effective, safe, and compliable for patients with facial angiofibromata, providing a satisfactory outcome adaptable to the daily dermatological and plastic surgery practice. [ABSTRACT FROM AUTHOR]

In recent times, photonic synthesis and processing of arbitrary microwave waveforms have gained interest due to their high frequency and huge time–bandwidth product. This study reviews methods for producing dual‐chirp microwave waveforms, focusing mostly on system topologies based on external modulation techniques, such as cascaded Mach–Zehnder modulator (MZM), dual parallel MZM, and dual polarized MZM. Other photonic approaches, like using semiconductor laser and optical heterodyne detection methods, are also discussed. These techniques are preferable because of high frequency, enhanced time–bandwidth product, greater chirp rate, and many more advantages. Additionally, the difficulties associated with integrating the systems into real‐world applications are also addressed. [ABSTRACT FROM AUTHOR]

Parts with interior voids created by the LPBF process are known to have the potential to cause fracture when subjected to mechanical loading. In this research, the key process parameters such as laser thickness (LT), scanning speed (SS), and laser power (LP) were taken into consideration to avoid the void formations which was the major reason for affecting the structural integrity. So, void formations (V), ultimate tensile strength (UTS) and reduced modulus (RM) were considered as the response parameters in this study. The entropy-associated weighted aggregated sum product assessment (WASPAS) approach was implemented to examine the favorable conditions which substantiated that the LT is the most influential parameter in nucleation of voids. The verification experiments prove that the void formation was reduced by 98.6% and the UTS and RM were enhanced by 52.17 and 31.7%. [ABSTRACT FROM AUTHOR]

Background: Modern dentistry has increasingly valued conservative and biologically less invasive clinical practices, seeking to preserve the patients’ tissues and natural dental elements. Most extractions in the dental clinic are preceded by periodontal disease that presents bone and gingival tissue loss, compromising the aesthetics as well as the support of dental elements. Objectives: The clinical approach in these cases often involves bone exertion followed by the successful installation of osseointegrated implants. Material and Methods: In this study, a case of extensive periodontal involvement and mobility of dental elements was carried out in a minimally invasive way, using the Er:YAG laser for periodontal decontamination and the hemolasertherapy technique to regenerate adjacent tissues, totaling nine weeks of treatment. Results: Clinical and radiographical improvement of tissue health and complete preservation of dental elements were observed. Conclusion: The patient underwent a follow-up appointment 2 years after the start of treatment when it was still possible to verify the stability of the clinical condition and the tissue gains obtained. [ABSTRACT FROM AUTHOR]

Purpose: To compare the hearing results and clinical safety of patients undergoing stapes surgery with conventional technique and diode laser. Methods: Retrospective observational study, which included patients treated with primary stapes surgery performed between January 2009 and January 2020. Three audiometric measurements (PTA, GAP and SDS) were evaluated as main results, evaluated by analysis of covariance (controlling the preoperative value). Intraoperative and postoperative complications were also analyzed. Outcomes were measured 6 months (± 1 month) after surgery. Results: 153 cases were included, 97 operated with conventional technique and 56 with laser technique. Postoperative GAP ≤ 10 dB was obtained in 85.6% of the total sample, 82.5% in the conventional technique and 91.1% in the laser technique. Analysis of covariance showed no significant differences in the three surgery outcomes between the two groups (PTA, p = 0.277; GAP, p = 0.509 and SDS, p = 0.530). Regarding surgical complications, sensorineural damage was higher in the conventional technique group (p = 0.05). On the other hand, there were four cases of facial paresis, all in the laser group, three of them with the 980 nm laser. Conclusions: Stapedotomy offered a high percentage of hearing success in the two groups studied. There were no significant differences in audiometric result, but there was a differential presentation of complications, being more frequent sensorineural hearing loss in the conventional technique group and facial paresis in the laser group. [ABSTRACT FROM AUTHOR]

Pediatric procedure‐related pain management is often incompletely understood, inadequately addressed, and critical in influencing a child's lifelong relationship with the larger health care community. We highlight the evolution of ethics and expectations around optimizing periprocedural pain management as a fundamental human right. We investigate the state‐of‐the‐art of topical anesthetics, reviewing their mechanisms of action and providing comparisons of their relative safety and efficacy data to help guide clinical selection. In total, this two‐part review offers a combination of conventional approaches and innovative techniques that should be used multimodally—in series and in parallel—to help optimize pain management and provide alternatives to sedation medication and general anesthesia. [ABSTRACT FROM AUTHOR]

Background: Q‐switched (QS) Nd: YAG laser is one of the treatment options for solar lentigines (SLs). However, the incidence of post‐inflammatory hyperpigmentation (PIH) is a common complication, especially in dark‐complexioned skin. Isobutylamido thiazolyl resorcinol (ITR) has been reported as a preventive modality for ultraviolet B (UVB)‐induced hyperpigmentation. Aims: This study aims to evaluate the efficacy and safety of ITR for the prevention of laser‐induced PIH. Patients/Methods: A randomized, evaluator‐blinded study including 24 subjects with SLs was conducted. Three SLs of each patient were randomized into three groups, which were to apply ITR twice daily, once daily, and no application for 2 weeks. Thereafter, 532‐nm QS Nd: YAG laser was performed. Incidence of laser‐induced PIH, relative melanin index (RMI), mean luminance score (L*), hyperpigmentation score, and adverse events were recorded for 2 months post‐laser. Results: The incidence of PIH at the 4th week after laser treatment was significantly lower in the ITR twice‐daily group compared to the no‐application group (20.83% vs. 50%, p = 0.028). There was no statistically significant difference in RMI, mean L*, and hyperpigmentation score between treatments at all visits. No serious adverse events were reported regarding ITR application and laser treatment. Conclusion: Two‐week application of ITR prior to QS: Nd YAG laser treatment may potentially reduce the incidence of PIH. A longer duration of application, including after the laser procedure, may be more beneficial for the prevention of laser‐induced PIH. [ABSTRACT FROM AUTHOR]

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Machining composite to achieve the desired surface and sub-surface condition, whether through conventional or non-conventional techniques, presents persistent challenges due to their anisotropic thermal characteristics. These challenges escalate when dealing with ceramic matrix composites (CMC) due to their high melting and boiling temperature. This study investigates the surface and sub-surface characteristics of SiC-Al 2 O 3 CMC laser-cut components, produced using a 2 kW quasi-continuous wave laser. The influence of laser parameters such as focal position, cutting speed, number of cutting passes, average power, and assist gas type on surface and sub-surface characteristics have been investigated in detail. The laser cut samples were analysed using white light interferometer, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX) and 3D X-ray Computer Tomography (XCT) for both surface and sub-surface characteristics. The effect of laser process parameters on the surface composition, surface topology, and sub-surface thermal defects have been studied in detail. The results revealed that multi-pass cutting (16 pass) can be used to achieve lower thermal affected zone (~200 µm) and reduced surface roughness with an overall cutting speed of 625 mm/min. No delamination was observed with multi-pass cutting. Nitrogen was found to be the most suitable assist gas, as it prevented oxide layer formation across the laser cut SiC-Al 2 O 3 CMC surface. [ABSTRACT FROM AUTHOR]

The management of renal stones, particularly those less than 2 cm in diameter, has changed with the development of endourological techniques, among which flexible ureteroscopy (FURS) using laser for lithotripsy has become a cornerstone. This study aims to compare the effectiveness of high pulse energy versus low pulse energy laser settings in renal stone dusting by Holmium YAG laser. This prospective randomized study was conducted between September 2021 and November 2023 to compare the efficacy and safety of high energy versus low-energy pulse settings using a Holmium: YAG laser dusting of renal stones less than 2 cm in diameter. A total of 174 adult patients were included, divided equally into high- and low-pulse energy groups, based on the energy settings of the laser high energy (ranged from 1.2–2.5 Joules and frequency of 8 hz) and low energy (less than 0.5 Joules and frequency ≥ 15 hz) using the dusting ‎technique with non-touch non-stop approach. The study sought to evaluate the impact of these settings on stone fragmentation efficiency, operative time, laser energy consumption, and postoperative outcomes, including stone-free rates and complications. The study involved 174 patients who underwent renal stone lithotripsy and showed that using high pulse energy laser dusting settings significantly reduced operative times and more rapid dusting compared to low pulse energy settings, without affecting the stone-free rate. The study observed no significant differences in stone size or location between both groups. Minor postoperative complications were similar between both groups, indicating high pulse energy settings for lithotripsy dusting. The efficacy of high pulse energy dusting in enhancing stone removal during surgery, potentially reducing operative time. Further validation through larger-scale studies is needed to solidify these findings. This technique presents a promising solution, particularly in regions with limited resources where acquiring expensive laser equipment is challenging. [ABSTRACT FROM AUTHOR]

There is limited information on the repairability of prostheses produced with digital technology. This study aims to evaluate various surface treatments on flexural bond strength of repaired dentured base resins produced by digital and conventional methods. A total of 360 samples were prepared from one heat-polymerized, one CAD/CAM milled and one 3D printed denture base materials. All of the test samples were subjected to thermocycling (5–55 °C, 5000 cycles) before and after repair with auto-polymerizing acrylic resin. The test samples were divided into five subgroups according to the surface treatment: grinding with silicon carbide (SC), sandblasting with Al2O3 (SB), Er:YAG laser (L), plasma (P) and negative control (NC) group (no treatment). In addition, the positive control (PC) group consisted of intact samples for the flexural strength test. Surface roughness measurements were performed with a profilometer. After repairing the test samples, a universal test device determined the flexural strength values. Both the surface topography and the fractured surfaces of samples were examined by SEM analysis. The elemental composition of the tested samples was analyzed by EDS. Kruskal–Wallis and Mann–Whitney U tests were performed for statistical analysis of data. SB and L surface treatments statistically significantly increased the surface roughness values of all three materials compared to NC subgroups (p < 0.001). The flexural strength values of the PC groups in all three test materials were significantly higher than those of the other groups (p < 0.001). The repair flexural strength values were statistically different between the SC–SB, L–SB, and NC–SB subgroups for the CAD/CAM groups, and the L–SC and L–NC subgroups for the 3D groups (p < 0.001). The surface treatments applied to the CAD/CAM and heat-polymerized groups did not result in a statistically significant difference in the repair flexural strength values compared to the NC groups (p > 0.05). Laser surface treatment has been the most powerful repair method for 3D printing technique. Surface treatments led to similar repair flexural strengths to untreated groups for CAD/CAM milled and heat-polymerized test samples. [ABSTRACT FROM AUTHOR]

This paper address the performance optimization of the battery heat sink module by analyzing the lattice structure of the battery heat sink module through in-depth modeling and simulation, and combining the laser powder bed fusion (LPBF)-forming technology with mechanical and corrosion resistance experiments for a comprehensive study. It is found that the introduction of the lattice skeleton significantly improves the thermal conductivity of the phase change material (PCM), realizing the efficient distribution and fast transfer of heat in the system. At the same time, the lattice skeleton makes the heat distribution in the heat exchanger more uniform, improves the utilization rate of the PCM, and helps to maintain the stability of the cell temperature. In addition, the melting of PCM in the lattice heat exchanger is more uniform, thus maximizing its latent heat capacity. In summary, by optimizing the lattice structure and introducing the lattice skeleton, this study successfully improves the performance of the battery heat dissipation system, which provides a strong guarantee for the high efficiency and stable operation of the battery, and provides new ideas and references for the development of the battery heat dissipation technology. [ABSTRACT FROM AUTHOR]

The development of unique optical materials that provide amplification and lasing in new wavelength ranges is a major scientific problem, the solution of which is becoming the basis for the emergence of new optical technologies, which are primarily targeting the expanding of operating wavelengths in silica glass. In fact, one of the notable advances in the field of fiber optics over the past two decades has been the production of a new type of laser-active fibers (namely bismuth-doped fibers), which has made it possible to cover previously inaccessible (for rare-earth-doped fibers) spectral ranges, in particular O-, E-, S-, and U-telecom bands. The advance in this direction has led to further growth of the technological capabilities in the telecom industry for amplification and generation of optical radiation in various wavelength bands, which will result in the near future to overcoming the problem known as "capacity crunch" by means of expanding the data transmission range. Recently, bismuth-doped fibers have been actively studying in order to improve their characteristics, which would allow for efficient implementation of optical devices based on bismuth-doped fibers (BDFs) with deployed telecommunications systems. This is one of the dynamically developing areas, where progress has already manifested in form of emergence of new achievements, in particular commercially available various types of BDFs, as well as a series of novel fiber-optic amplifiers for the O- and E-bands. In this review, a number of scientific studies that have already led to a noticeable progress in the field of optical properties of BDFs and the practical implementation of optical devices (lasers and amplifiers) based on them are presented and discussed, with much attention to the achievements of recent years. [ABSTRACT FROM AUTHOR]

Si is opaque to visible light, but transparent to infrared rays. Therefore, when the infrared laser is focused inside Si, the focal portion becomes ultra-hot, forming a modified volume (Laser induced modified volume: LIMV) inside. After the laser beam is injected into the Si wafer at equal intervals (for example, 5 µm) in the cross direction, and then a force is applied from the outside. Then, cracks are formed from LIMV, and the Si wafer is divided into small pieces of 5 µm square. This is the stealth dicing (SD) technology, which is now widely used in the manufacture of semiconductor devices. In this process, clarifying the nature of LIMV is of great industrial and academic significance. The authors have been engaged in elucidating the mechanism of LIMV development by TEM observation. This phenomenon, which at first seemed extremely puzzling, was finally elucidated. In this overview, we would like to describe the process that led to this elucidation in chronological order. This phenomenon is extremely puzzling, and due to the author’s lack of knowledge, there were errors in the contents of the papers published so far, so we have corrected them in this overview. [ABSTRACT FROM AUTHOR]

Photobiomodulation therapy (PBMT) has become increasingly utilized in the zoo and aquarium fields to treat ailments in various species; however, its use in teleosts and elasmobranchs is relatively underrepresented in the literature. This study examined the efficacy of PBMT as an adjunct treatment to reduce the healing time of dermal abrasions in cownose rays (Rhinoptera bonasus). Ten cownose rays were included in this study and separated into control (n = 5) and treatment groups (n = 5). Animals in both treatment and control groups received intramuscular injections of enrofloxacin every 72 h to provide broad‐spectrum antibiotic coverage. Cownose rays in the treatment group additionally received PBMT using the Companion® CTC‐12 unit using the large, noncontact head. Control group rays were subjected to identical handling without the use of PBMT. A total of 196 Joules were delivered at a power of 2 W based on a dose of 5 J/cm2 at each session. Observational analysis revealed a lack of appreciable difference in healing time between the treatment and control groups in the aforementioned settings; however, it is recommended that PBMT protocols should be re‐evaluated if there is little to no response in healing after three to four sessions. PBMT use on acute superficial dermal abrasions in cownose rays was well‐tolerated in this study and may have utility in a multimodal treatment approach to wound healing. This study also produced a wound scoring metric based on photographs captured at each treatment. Future studies should utilize increased fluence (J/cm2) and irradiance (W/cm2) and incorporate synchronous histological analysis and increased sample size. Research Highlights: Photobiomodulation therapy (PBMT) appears to be safe for use in the cownose ray as an adjunct treatment for acute dermal abrasions.PBMT application did not significantly reduce treatment time; however, treatment parameters, wound size, location, and catch‐up trauma were confounding variables in this study.Wound scoring was conducted to develop a scoring system to standardize subjective qualification of wounds in cownose rays. [ABSTRACT FROM AUTHOR]

In the filtered optical feedback system, a part of the emission of the laser is spectrally filtered, here by a Fabry–Perot (FP) filter, and then fed back into the quantum-dot (QD) laser cavity. This technique has been used in various applications such as inducing frequency dynamics in QD semiconductor lasers and studying the dynamical behavior of a QD semiconductor laser subject to delayed filtered optical feedback. We report on the systematical investigation of the steady-state regime and the dynamical behavior of a QD semiconductor laser subject to delayed FOF. The effects of the filter on the locking of the QD laser frequency to the external cavity modes are described. We report and observe hysteresis, bistability, and multistability and show that all these are well described by a set of rate equations for the coupled QD laser and FP cavity system. We also present a stability diagram that summarizes the dynamical behavior of the system. [ABSTRACT FROM AUTHOR]

The SI unit of pressure, i.e., pascal is realized with mechanical devices such as ultrasonic interferometer manometers and pressure balances for the pressure range 1 Pa–100 kPa. Recently, optical interferometer manometers are being used to realize pascal. Such a realization is mercury-free and environmentally friendly and does not depend on any mechanical motions as in piston gauges and is based on physical constants. It consists of an optical Fabry–Perot cavity as a refractometer and is based on the measurement of the resonant frequency of the cavity using lasers. In this paper, we report the theoretical calculations for such an optical cavity and discuss various parameters for the laser required for developing such a cavity-based refractometer system. We present the mechanical design for the dual cavity and an all-fiber optical set-up to be used for the next generation of primary pressure standards in the barometric region of pressure at CSIR-National physical laboratory, India. [ABSTRACT FROM AUTHOR]

THE PRESENT experiment was undertaken to study the behavior of titanium in soil and the effect of application methods (foliar spraying or soil injection) and TiO2 concentrations (0, 5, 7.5, and 10 ppm as nanoparticles or 25, 50, and 75 ppm as bulk particles) as well as their interaction treatments on Salvia fruticosa (three-lobed sage) plant. In most cases, the tallest plants, the maximum yield of dry herb/feddan, yield of volatile oil/feddan, values of chlorophyll, and nitrogen, phosphorous, and potassium (NPK) values of Salvia fruticosa were achieved from the interaction treatment between foliar spraying and 10 ppm TiO2 nanoparticles while the main components of three-lobed sage essential oil were 1,8-cineole, camphor, α-pinene, and camphene, respectively. Also, from the sequential extraction method of Ti in soil, the highest fraction of Ti was found in residual forms at each of the treatments. This confirmed that using TiO2 (bulk or nanoparticles) in either soil or foliar application is harmless and improved chlorophyll production and consequently improved photosynthesis which leads to increased productivity of the plants under this study. [ABSTRACT FROM AUTHOR]

Background and Objectives: The 1444 nm wavelength Neodymium:Yttrium–Aluminum–Garnet (Nd:YAG) laser treatment is an efficient method for treating axillary osmidrosis (AO); however, it has a relatively low treatment persistence. To address this issue, we performed integrated liposuction surgery with a laser to treat AO and compared the results with those of a group treated only with a laser. Materials and Methods: This study compared the outcomes of AO treatment between the two groups up to six months postoperatively. The first group of 18 patients underwent laser treatment alone, and the second group of 12 patients underwent integrated liposuction surgery in addition to laser treatment. Outcomes were assessed using the following variables: degree of malodor (DOM), sweating area, patient satisfaction, pain levels, and complications, such as burns, swelling, and contractures. Results: Compared to the laser-only group, the integrated liposuction group demonstrated significantly superior outcomes in terms of DOM (p = 0.002) and patient satisfaction (p = 0.006), as well as a reduction in the sweating area (p = 0.012). The pain rating was higher in the liposuction group, but the difference was not statistically significant (p = 0.054). Compared with the patients in the integrated liposuction treatment group, those in the laser treatment group exhibited a significantly higher number of burns under the axillae (p = 0.025). However, no significant differences were observed in the swelling or contracture between the groups. Conclusions: Integrated liposuction with laser therapy significantly improved treatment outcomes, including malodor, patient satisfaction, sweat test results, and decreased complication rates. [ABSTRACT FROM AUTHOR]

Abstract Objectives This study aimed to compare the tissue dissolving capacities of sodium and calcium hypochlorite [NaOCl and Ca(OCl)2] solutions applied without activation or with two irrigant activation methods. Materials and Methods One hundred and eight dentin cavities were prepared. Preweighed tissue pieces were placed in these dentin cavities, and samples were divided into nine groups of twelve. In groups 1, 2, and 3, NaOCl was used with non-activation (NA), passive ultrasonic (PUA), and laser activation (LA). With the same techniques, Ca(OCl)2 was used in groups 4, 5, and 6, and distilled water was used in groups 7, 8, and 9. The weight loss of tissue samples was calculated and analyzed using Two-way ANOVA and Duncan tests. Results Distilled water groups showed no tissue dissolution in any conditions. NaOCI and Ca(OCI)2 showed statistically similar dissolving effectiveness when used with the same technique. Activated groups dissolved significantly greater tissue than non-activated ones, the highest in LA. Conclusions Ca(OCI)2 can be an alternative to NaOCl; for both, the first choice of activation may be the LA.

Background and objective: Recently, the new pulsed thulium:yttrium aluminum garnet (p-Tm:YAG) laser technology has been introduced in endourology for lithotripsy. The aim of this study was to assess and validate the clinical laser performance and safety profile of p-Tm:YAG laser in a series of patients with renal and ureteral stones who underwent flexible ureteroscopy (fURS). Methods: Prospective data were collected for patients who underwent fURS with the p-Tm:YAG laser Thulio (Dornier MedTech Systems GmbH, Wessling, Germany) at our institution by using two different laser fiber core diameters (270 and 200 μm). The primary endpoint of the study was stone-free rate (SFR), and the secondary endpoints were Clavien-Dindo complications grade ≥1 and the comparison between laser fibers of different diameters in all the parameters analyzed. Descriptive statistics relied on medians and interquartile ranges for continuous covariates, and on frequencies and percentages for categorical covariates. After stratification according to fiber types, differences between groups were tested with Wilcoxon and chi-square tests as appropriate. All the analyses and graphics were performed using R software (version 4.2.2). Key findings and limitations: The SFR was 82% at 1-mo follow-up. In six out of 50 procedures (12%), Clavien-Dindo grade I–II complications were recorded. There were no differences regarding all the laser parameters considered between patients who were treated with 270 or 200 μm laser fibers (p > 0.05). Limitations of the study include small sample size in a single center and the lack of comparative groups. Conclusions and clinical implications: In this prospective study of 50 patients who underwent fURS for ureteral and renal stones, the p-Tm:YAG laser Thulio was both effective and safe in a short-term follow-up. More prospective randomized studies in larger populations using different laser sources are required to confirm the clinical laser performance and safety of p-Tm:YAG laser for urinary stones treatment. Patient summary: In this report, we looked at the outcomes for the pulsed thulium:yttrium aluminum garnet laser Dornier Thulio in patients who underwent flexible ureteroscopy for ureteral and renal stones. We found that this new laser technology is effective and safe, representing a good alternative to the other laser machines available for stone lithotripsy. We need more studies with larger populations to establish the superiority of this laser technology over the others.

Background: Hidradenitis supprativa is a chronic inflammatory skin disease that can respond to treatment with laser hair removal. Objective: To assess alexandrite laser hair removal laser as a treatment for hidradenitis suppurativa as measured by the Hidradenitis Supprativa Clinical Response. Materials and methods: We conducted a prospective, randomized, controlled study in adult patients with hidradenitis supprativa. Participants underwent a series of 4 monthly laser treatments to 1 side of the body, with the contralateral side serving as a control. The primary outcome was Hidradenitis Supprativa Clinical Response at week 24, 8 weeks after the final laser treatment. Results: The percent improvement across treated sites after 4 treatments was 72.73% axillary, 70% inguinal, and 100% inframammary. Across all body regions, Hidradenitis Supprativa Clinical Response was significantly higher for the sites treated with the alexandrite laser compared to the contralateral controls: 75% vs 33.33% (P = .0046, 95% CI: [0.16, 1]). Limitations: The limitations of this study include a small sample size from which the data was collected. Conclusions: The 775-nm alexandrite laser is a safe and effective treatment for hidradenitis supprativa at various anatomic sites in both resolving preexisting lesions and preventing new eruptions.

Background and Objective: Removal of skin tattoos by Q-switched (QS) Nd:YAG laser is a common procedure, but its results vary. For successful tattoo removal, laser applications are combined with various methods. In laser tattoo removal, pigments are removed from the region by the lymphatic system after they are broken down into small pieces. It is hypothesized that induction with platelet-rich plasma (PRP) can increase the total amount of pigments removed in the laser tattoo removal process and possibly reduce the visibility of the remaining pigments by thickening and renewing the skin. For this purpose, a study investigating the combination of laser tattoo removal with PRP was planned. Materials and Methods: The study was planned on rats divided into three groups (with eight rats each). Four rats were used for PRP preparation. All rats were tattooed on both arms and legs. One month after the rats were tattooed, QS Nd:YAG laser and PRP or saline injections were applied to the tattoos. The tattoos were measured, photographed, and evaluated by macroscopy and dermoscopy shortly before laser application and at 1 and 2 months after laser application. Regional lymph node dissection was performed. Results: After laser application, all the tattoos showed some pigment removal. There was no significant difference in tattoo removal with various wavelengths (1064/532 nm) or with a 25% increase in laser power. Although skin quality was found to be better in the PRP-injected group, the difference was not significant compared with that in the group with saline injections. In all subjects, at least one pigmented lymph node was seen in all dissection areas. Conclusions: Laser application is effective in the removal of tattoos. However, although the combination of PRP and laser has a positive effect on the quality of the skin, it does not provide a significant positive effect on tattoo removal.

Evdokia Sourla, Peck Lin Lip Birmingham and Midland Eye Centre, Sandwell & West Birmingham Hospitals NHS Trust, Birmingham, UKCorrespondence: Peck Lin Lip, Email pllipwoo@gmail.comAbstract: Severe sickle retinopathy is commonly known in adults but not in children, hence any related treatment for sickle retinopathy in children was not well described. We reported 2 paediatric sickle patients (aged 12 and 13) presented with severe sickle retinopathy and described details of their disease progression and treatments over 2– 3 years, along with the challenges faced when managing this particular group of young age sickle cell patients. Our case reports also demonstrated the benefits of laser photocoagulation treatment to early sickle proliferative disease, and how complications from advanced severe retinopathy hindered effective treatments.Keywords: children, seafans, vitreous hemorrhage, laser, traction, salmon patch

Abstract Considering the superior luminous intensity characteristics of lasers, a thermal simulation platform employing laser-induced heating in an aerobic environment was developed. Achieving a uniformly distributed flat-topped square laser beam output was facilitated through optical fibre bundling techniques, while precise control over laser power output was attained through current modulation. Utilising the aforementioned system, thermal shock simulation experiments were conducted in an aerobic environment, subjecting two types of high-temperature-resistant composites, namely C/C and C/SiC, to temperatures up to 1800 °C. These composites were lightweight, heat-resistant materials designed for hypersonic vehicle applications. The results show that the system and method can be used to simulate high temperatures, rapid temperature increases, and thermal shocks on C/C composite materials, with minimal variation in the coupling coefficient under aerobic conditions. The system and method can also provide key technology support for thermal-force-oxygen coupling testing of high temperature resistant materials.

Angiofibromas are a common facial manifestation of tuberous sclerosis (TS). However, current treatments have proven ineffective due to high recurrence rates and noncompliance. To address this issue, we developed a new triple laser therapy protocol for more effective management of angiofibromas. We conducted tests to validate its efficacy. This is a prospective study of 10 patients with TS (4 women and 6 men, mean age 26.3 years [15–37 years]) with angiofibromata who received triple sequential laser therapy at our private dermatological clinic conducted from January 2000 to December 2022. We evaluated the outcome with the Facial Angiofibromata Severity Index (FASI) via clinical photography (0, 6 months, 1 year, and 2 years), and Dermatology Life Quality Index (DLQI). All patients had a successful recovery without any complications. Among these 10 patients, 4 experienced localized recurrences at their 6-month follow-up. These recurrences were treated with a second single carbon dioxide laser session. After 2 years of follow-up, we observed no recurring facial cutaneous manifestations. Furthermore, all patients experienced a decrease in their FASI score after treatment. According to the Visual Analogue Scale, patients reported 95% satisfaction, and DLQI indicated only a minor impact on their everyday lives. We believe that this protocol of three-step laser treatment is effective, safe, and compliable for patients with facial angiofibromata, providing a satisfactory outcome adaptable to the daily dermatological and plastic surgery practice.

Owing to their large accelerating gradients, plasma-based accelerators have attracted considerable interest as potential drivers for future, compact electron-positron colliders. Despite great progress achieved in plasma-based electron acceleration, positron acceleration still remains a challenging task, with an efficient positron source being the prerequisite for such acceleration. Here a concept for a compact, two-stage plasma-based positron source is discussed. In the first stage the positrons are created by a multi GeV electron beam produced by a laser-plasma accelerator interacting with a solid density foil. In the second stage the positrons are captured and accelerated in a plasma wave driven by either an electron beam or a laser pulse. Three potential configurations of such a source are considered: (i) a single electron beam is used for both the creation of positrons in the foil and for driving the wakefield in the second stage; (ii) a train of two electron beams is used: the positrons produced by the trailing beam in the foil are captured and accelerated in the second stage by the plasma wave generated by the leading beam; and (iii) a single electron beam is used to produce positrons in the foil and an independent laser pulse is coupled to the second stage to drive the plasma wave. These three configurations show different degrees of effectiveness with positron capture efficiency, varying from less than a percent to almost half of all produced positrons.

ObjectivesDuring holmium:yttrium-aluminum-garnet (holmium:YAG) laser lithotripsy to break urinary stones, urologists frequently see flashes of light. As infrared laser pulses are invisible, what is the source of light? Here we studied the origin, characteristics, and some effects of flashes of light in laser lithotripsy.MethodsUltrahigh-speed video-microscopy was used to record single laser pulses at 0.2-1.0 J energy lasered with 242 µm glass-core-diameter fibers in contact with whole surgically retrieved urinary stones and hydroxyapatite (HA)-coated glass slides in air and water. Acoustic transients were measured with a hydrophone. Visible-light and infrared photodetectors resolved temporal profiles of visible-light emission and infrared-laser pulses.ResultsTemporal profiles of laser pulses showed intensity spikes of various duration and amplitude. The pulses were seen to produce dim light and bright sparks with submicrosecond risetime. The spark produced by the intensity spike at the beginning of laser pulse generated a shock wave in the surrounding liquid. The subsequent sparks were in a vapor bubble and generated no shock waves. Sparks enhanced absorption of laser radiation, indicative of plasma formation and optical breakdown. The occurrence and number of sparks varied even with the same urinary stone. Sparks were consistently observed at laser energy >0.5 J with HA-coated glass slides. The slides broke or cracked by cavitation with sparks in 63 ± 15% of pulses (1.0 J, N = 60). No glass-slide breakage occurred without sparks (1.0 J, N = 500).ConclusionUnappreciated in previous studies, plasma formation with free-running long-pulse holmium:YAG lasers can be an additional physical mechanism of action in laser procedures.

Machining, micro machining, and laser processing are key manufacturing processes for the medical device industry. They continue to grow in popularity because they produce high-precision, small-profile components and sub-assemblies with [...]