Vapor Channel Oscillations in Laser Lithotripsy.

Objectives: Laser-based endoscopic procedures present special challenges to deliver energy for ablation or coagulation of target tissues. When optical fiber-target quasi-contact (< 0.5 mm distance) cannot be maintained or is undesirable, the creation of intervening vapor bubbles and channels provide for the necessary transmission of laser energy to the target.

Treatment of Urolithiasis with Thulium Fiber Laser in Fragmentation Mode Using Optimized Pulse Sequences.

The super-pulsed thulium fiber laser (SP TFL) is a new alternative to high-power holmium laser for intracorporeal lithotripsy. The SP TFL has shown advantages in dusting regimes, but benefits in fragmentation regimes are less understood. The second-generation SP TFL introduces an advanced fragmentation pulse (AFP) sequence to maximize SP TFL's efficiency in fragmentation.

Novel 40 µm spot size 3050/3200 nm DFG laser versus CO laser for laser-assisted drug delivery.

Background And Objectives: The use of ablative fractional lasers to enhance the delivery of topical drugs through the skin is known as laser-assisted drug delivery. Here, we compare a novel 3050/3200 nm difference frequency generation (DFG) fiber laser (spot size: 40 µm) to a commercially used CO laser (spot size: 120 µm). The objective is to determine whether differences in spot size and coagulation zone (CZ) thickness influence drug uptake.

Extracorporeal membrane oxygenators with light-diffusing fibers for treatment of carbon monoxide poisoning: Experiments, mathematical modeling, and performance assessment with unit cells.

Unlabelled: BACKGROUND AND OBJECTIVES: Approximately 50,000 emergency department visits per year due to carbon monoxide (CO) poisoning occur in the United States alone. Tissue hypoxia can occur at very low CO concentration exposures because CO binds with a 250-fold higher affinity than oxygen to hemoglobin. The most effective therapy is 100% hyperbaric oxygen (HBO) respiration.

Assessment of a 3050/3200 nm fiber laser system for ablative fractional laser treatments in dermatology.

Background And Objectives: Mid-infrared (IR) ablative fractional laser treatments are highly efficacious for improving the appearance of a variety of dermatological conditions such as photo-aged skin. However, articulated arms are necessary to transmit the mid-IR light to the skin, which restricts practicality and clinical use. Here, we have assessed and characterized a novel fiber laser-pumped difference frequency generation (DFG) system that generates ablative fractional lesions and compared it to clinically and commercially available thulium fiber, Erbium:YAG (Er:YAG), and CO lasers.

Preclinical comparison of superpulse thulium fiber laser and a holmium:YAG laser for lithotripsy.

Purpose: A superpulse (500 W peak power) thulium fiber laser operating at a 1940 nm wavelength, suitable for lithotripsy, has recently been developed. The goal of this study was to compare stone fragmentation and dusting performance of the prototype superpulse thulium fiber laser with leading commercially available, high-power holmium:YAG lithotripters (wavelength 2100 nm) in a controlled in vitro environment.

Methods: Two experimental setups were designed for investigating stone ablation rates and retropulsion effects, respectively.

Peroxide dental bleaching via laser microchannels and tooth color measurements.

The aim of this study was to use microchannels drilled by an Er:YAG laser into a human tooth through the enamel into the dentin for direct injection of hydrogen peroxide (HP) to produce a minimally invasive, rapid, tooth bleaching effect. The experiments were conducted in vitro. Five microchannels with a diameter of ?200???m and a depth of ?2??mm were drilled through the palatal side of a human tooth crown using the microbeam of an Er:YAG-laser with a wavelength of 2.

Polarization enhanced wide-field imaging for evaluating dermal changes caused by non-ablative fractional laser treatment.

Background And Objective: Laser non-ablative fractional treatment (NAFT) is an important part of armamentarium of modern dermatology. Recently, such treatments have become available in at-home setting due to advent of self-application NAFT devices. Safety and clinical efficacy of NAFT are well established in multiple studies.

Uncovering dental implants using a new thermo-optically powered (TOP) technology with tissue air-cooling.

Background And Objectives: Uncovering implants with lasers, while bloodless, has been associated with a risk of implant and bone overheating. The present study evaluated the effect of using a new generation of high-power diode lasers on the temperature of a dental implant and the surrounding tissues using an in vitro model.

Study Design/materials And Methods: The implant temperature was measured at three locations using micro thermocouples.

Transcutaneous delivery of micro- and nanoparticles with laser microporation.

Fractional laser ablation is one of the relatively safe and minimally invasive methods used to administer micro- and nanoparticles into the skin at sufficiently large depth. In this article, we present the results of delivery of TiO₂ nanoparticles and Al₂O₃ microparticles into skin. Fractional laser microablation of skin was provided by a system based on a pulsed Er:YAG laser with the following parameters: the wavelength 2940 nm, the pulse energy 3.

Fat tissue histological study at indocyanine green-mediated photothermal/photodynamic treatment of the skin in vivo.

Histological slices of skin samples with the subcutaneous adipose tissue after photothermal/photodynamic treatment are analyzed. In the case of subcutaneous indocyanine green injection and 808-nm diode laser exposure of the rat skin site in vivo, the greatest changes in tissue condition were observed. Processes were characterized by dystrophy, necrosis, and desquamation of the epithelial cells, swelling and necrosis of the connective tissue, and widespread necrosis of the subcutaneous adipose tissue.

Evaluation of a fractional laser with optical compression pins.

Background And Objective: Non-ablative fractional lasers have been used in skin rejuvenation procedures with some success. In general, the optimum area coverage and depths of the fractional thermal injury zones depend on the specific indications of interest. For all fractional devices, depth is adjusted with energy that also determines the coagulation area at the dermal/epidermal junction.

Characterization of an optimized light source and comparison to pulsed dye laser for superficial and deep vessel clearance.

Background And Objective: An arc lamp-based device providing optimized spectrum and pulse shape was characterized and compared with two pulsed dye laser (PDL) systems using a vascular phantom. Safety and effectiveness for facial telangiectasia are presented in clinical case studies.

Study Design/materials And Methods: An optimized pulsed light source's (OPL) spectral and power output were characterized and compared with two 595 nm PDL devices.

The role of laser tunnels in laser-assisted lipolysis.

Background And Objectives: Laser-assisted lipolysis (LAL) devices are used as adjuncts to liposuction that create laser tunnels to heat the adipose and connective tissue. Available systems vary significantly across choice of wavelengths, power delivery, and tip design. Rationale are developed for optimum laser parameters evaluated with physical principles and in controlled ex vivo tests.

Semi-Automated method of analysis of horizontal histological sections of skin for objective evaluation of fractional devices.

Background And Objective: The treatment of skin with fractional devices creates columns of micro-ablation or micro-denaturation depending on the device. Since the geometric profiles of thermal damage depend on the treatment parameters or physical properties of the treated tissue, the size of these columns may vary from a few microns to a few millimeters. For objective evaluation of the damage profiles generated by fractional devices, this report describes an innovative and efficient method of processing and evaluating horizontal sections of skin using a novel software program.

Pilot investigation of the correlation between histological and clinical effects of infrared fractional resurfacing lasers.

Methods: Yucatan Black pig skin was treated with a 1,540-nm erbium (Er):glass laser (Lux1540, 15 and 30 mJ) and two 1,550-nm Er-doped fiber lasers (Fraxel SR750 and SR1500, 8, 10, and 12 mJ). Histologic sections were examined to determine the depth of damage and to correlate subjects' clinical response. Concurrently, six subjects with photodamaged skin received three split-face and ipsilateral dorsal hand treatments with the 1,540-nm Er:glass laser on one side and one of the 1,550-nm Er-doped lasers (Fraxel SR750) on the other.

Optical clearing of human skin: comparative study of permeability and dehydration of intact and photothermally perforated skin.

Accelerated diffusion of water and hyperosmotic optical clearing agents is studied as a result of enhanced epidermal permeability. A lattice of microzones (islets) of damage in stratum corneum is induced using a flash-lamp applique system. An optical clearing agent composed of 88% glycerol in aqueous solution is used for all experiments.

Micro-fractional ablative skin resurfacing with two novel erbium laser systems.

Background And Objectives: Fractional ablation offers the potential benefits of full-surface ablative skin resurfacing while minimizing adverse effects. The purpose of this study was to evaluate the safety, damage profile, and efficacy of erbium fractional lasers.

Materials And Methods: Histology from animal and human skin as well as clinical evaluations were conducted with erbium YAG (2,940 nm) and erbium YSGG (2,790 nm) fractional lasers varying pulse width, microbeam (microb) energy, number of passes, and stacking of pulses.

Intense pulsed light and laser treatment of facial telangiectasias and dyspigmentation: some theoretical and practical comparisons.

Background And Objective: A comparative overview is presented, both theoretical and clinical, for intense pulsed light (IPL) and laser treatment of facial telangiectasias and pigmented lesions.

Materials And Methods: A narrative approach describes light penetration into the epidermis, dermis, dermal-epidermal junction, and facial ectasias. Based on mathematical models, we examine some temperature profiles for monochromatic and broadband light sources.

Low-intensity indocyanine-green laser phototherapy of acne vulgaris: pilot study.

Near infrared (NIR) diode laser low-intensity (soft) phototherapy with the topical application of indocyanine green (ICG) has been suggested for treatment of acne vulgaris. Twelve volunteers with acne lesions on their faces and/or backs were enrolled in the experiment. Skin areas of the subjects that were 4 x 5 cm2 were stained with ICG solution for 5 min before laser irradiation (803 nm) at a power density up to 50 mW/cm2 for 5 to 10 min.

A pilot study of ICG laser therapy of acne vulgaris: photodynamic and photothermolysis treatment.

Background And Objectives: The near-infrared (NIR) laser radiation due to its high penetration depth is widely used in phototherapy. In application to skin appendages, a high selectivity of laser treatment is needed to prevent light action on surrounding tissues. Indocyanine green (ICG) dye may provide a high selectivity of treatment due to effective ICG uploading by a target and its narrow band of considerable absorption just at the wavelength of the NIR diode laser.

In vitro and in vivo study of dye diffusion into the human skin and hair follicles.

We present experimental results on the in vitro and in vivo study of dye diffusion into human skin and hair follicles. We have studied some commercially available dyes for potential using in the laser selective thermolysis. The degree and the depth of hair follicle dyeing inside the skin were determined.