- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Laser Doppler blood flowmeter as a useful instrument for the early detection of lower extremity peripheral arterial disease in hemodialysis patients: an observational study
摘要： Background: A simpler method for detecting atherosclerosis obliterans is required in the clinical setting. Laser Doppler flowmetry (LDF) is easy to perform and can accurately detect deterioration in skin perfusion. We performed LDF for hemodialysis patients to determine the correlations between blood flow in the lower limbs and peripheral arterial disease (PAD). Methods: This retrospective study included 128 hemodialysis patients. Patients were categorized into the non-PAD group (n = 106) and PAD group (n = 22), 14 early stage PAD patients were included in the PAD group. We conducted LDF for the plantar area and dorsal area of the foot and examined skin perfusion pressure (SPP) during dialysis. Results: SPP-Dorsal Area values were 82.1 ± 22.0 mmHg in the non-PAD, and 59.1 ± 20.3 mmHg in PAD group, respectively (p < 0.05). The LDF-Plantar blood flow (Qb) values were 32.7 ± 15.5 mL/min in non-PAD group and 21.5 ± 11.3 mL/min in PAD group (p < 0.001). A total of 21 non-PAD patients underwent LDF before and during dialysis. The LDF-Plantar-Qb values were 36.5 ± 17.6 mL/min before dialysis and 29.6 ± 17.7 mL/min after dialysis (p < 0.05). We adjusted SPP and LDF for PAD using logistic regression, SPP-Dorsal-Area and LDF-P were significantly correlated with PAD (p < 0.05). The receiver-operating characteristic curve analysis indicated cut-off values of 20.0 mL/min for LDF-Plantar-Qb during dialysis. Conclusion: LDF is a simple technique for sensitive detection of early-stage PAD. This assessment will help physicians identify early-stage PAD, including Fontaine stage II in clinical practice, thereby allowing prompt treatment.
关键词： Skin perfusion pressure,Peripheral arterial disease,Laser doppler flowmetry
更新于2025-09-16 10:30:52
-
[Laser Institute of America ILSC? 2019: Proceedings of the International Laser Safety Conference - South Kissimmee, Florida, USA (March 18–21, 2019)] International Laser Safety Conference - Visible lesion threshold modeling of skin laser exposure at 1070-nm
摘要： Computational models are capable of quantifying the expected thermal response of biological tissue to laser irradiation. A typical laser-tissue model accounts for optical energy deposition, heat transfer, and damage assessment, with calculation of the Arrhenius integral. Previous studies have successfully employed these methods to predict skin damage thresholds at laser wavelengths with high absorption in water, and usually for single continuous-wave exposures. However, there remains a need for a robust and accurate predictive model in low-absorption, high-scattering cases, such as for lasers in the near-infrared (NIR) region near 1 μm, where a large volume of tissue is heated simultaneously. This study presents a framework for modeling laser irradiation of skin tissue at 1070-nm for both continuous-wave and pulsed exposures with durations ranging from 10-2 to 101 seconds. We report the modeled skin thermal responses alongside thermal camera recordings of in-vivo porcine exposures as validation of simulation integrity. Comparisons of modeled damage thresholds calculated by the Arrhenius integral with past experimentally-determined minimum visible lesion ED50 data demonstrate a high degree of accuracy. The techniques outlined by this study provide a useful tool in assessing potentially hazardous near-infrared laser exposure scenarios while informing future investigations into modeling skin laser exposure at these wavelength regions.
关键词： near-infrared,Arrhenius integral,laser-tissue interaction,skin damage thresholds,computational modeling
更新于2025-09-16 10:30:52
-
The Elite Facial Surgery Practice (Development and Management) || 24 Laser Surgery
摘要： All lasers are not the same. They are tools or instruments that come in a variety of different forms and are designed to perform different tasks. Some lasers vaporize the outer layers of sun-damaged or aging skin. Some can also pass through the outer layers of the skin and destroy deeper birthmarks (port-wine stains) or tiny blood vessels (spider veins.) As is the case with most technology, the use of lasers is an art form that improves with training and experience. Lasers, like any technology, must be used for the right reasons. The right reason is that, in the facial surgeon's opinion, it is superior to other forms of treatment, in terms of safety and outcomes. For some conditions, lasers exceed other forms of treatment. For others, I have found laser therapies to be inferior. So, if training in dermabrasion and chemical peeling was not offered during residency or fellowship, it is recommended that the surgeon arrange to spend enough time with a colleague who performs these procedures to feel comfortable offering and performing them.
关键词： Leg Veins,Rosacea,Laser Surgery,Pigmented Spots,Acne,Laser Hair Removal,Skin Resurfacing,Dilated Blood Vessels
更新于2025-09-16 10:30:52
-
Iridescence and thermal properties of <i>Urosaurus ornatus</i> lizard skin described by a model of coupled photonic structures
摘要： This research shows that the morphological characteristics of the external microstructure of the beautiful skin of the Urosaurus ornatus lizard contribute to the explanation of the origin of their iridescent and thermal properties. High-resolution scanning electron microscopy studies revealed that the skin surface of the U. ornatus lizard is constituted by a semi-ordered array of hexagonal photonic crystals with sub-micrometric structural parameters. The iridescence properties of the ventral patch and dorsal surface of the U. ornatus lizard were numerically simulated modeling both surfaces by a set of coupled photonic crystals with structural parameters proposed from statistical measurements of the lattice parameter and holes diameter of its skin surface. The dorsal surface showed the ability to re?ect visible light and at least in a signi?cant range the ultraviolet and near infrared radiation. A complete photonic band gap for the transverse magnetic polarization mode of the incident light in both dorsal and ventral surfaces was predicted by calculations. The spectral re?ectance and the structure of photonic bands obtained explain the re?ection of the infrared radiation by the dorsal surface which might help to the thermoregulation of the lizard body. The results obtained suggest that the selective re?ection of incident light performed by the photonic structural array de?ned on the skin surface of the U. ornatus has a signi?cant contribution to its apparent color.
关键词： thermoregulation,iridescence properties,Urosaurus ornatus,organic photonic structures,skin surface model
更新于2025-09-16 10:30:52
-
Full-Field Erbium:YAG Laser Resurfacing: Complications and Suggested Safety Parameters
摘要： Background: Laser skin resurfacing with erbium-doped yttrium aluminum garnet (Er:YAG) lasers is a newer alternative to CO2 laser treatment, and was developed to reduce common complications. Although Er:YAG lasers have been available for years, safety parameters for efficacious resurfacing with these devices have not previously been available. Objectives: The aim of this study was to utilize one practice’s laser treatment settings and outcomes data to identify complication rates for various energies and areas of the face and to offer safe energy/depth parameters for treating each area. Methods: A retrospective chart review was performed for full-field confluent laser resurfacing patients treated with a Sciton Contour Tunable Resurfacing Er:YAG laser by the senior author. The data were retroactively analyzed with a time range of 8?years (January 2007-December 2015). Results: The overall complication rate for MicroLaserPeels (ablation of 50?μm or less) was 10.1% (20 of 198 treatments) and the rate for deep resurfacing treatments was 26.5% (71 of 268 cases). In MicroLaserPeel treatments the cheek area had the highest complication rate, followed by the forehead, nose, perioral, and eyelid areas, in that order (complication rate range, 0%-9.1%). In deep resurfacing treatments the perioral area had the highest complication rate, 38.6% of 145 cases. This was followed by the lids, cheek, nose, and forehead, in that order (complication rate range, 15.2%-20.9%). There is a correlation between increased depth of ablation and increased rate of complication. Conclusions: The study confirmed the efficacy of Er:YAG resurfacing and provides guidance for a safer approach to excellent outcomes.
关键词： complications,laser skin resurfacing,safety parameters,Er:YAG laser
更新于2025-09-16 10:30:52
-
In Vivo Experimental Study on the Enhancement of Optical Clearing Effect by Laser Irradiation in Conjunction with a Chemical Penetration Enhancer
摘要： The penetration of optical clearing agents (OCAs) is restricted by the natural barrier function of the stratum corneum (SC) of the skin, which can be breached by physical and chemical methods to enhance the transcutaneous delivery of OCAs. To breach the barrier function of SC, we carried out the in vivo experimental study to enhance the optical clearing effect of PEG-400 by laser irradiation in conjunction with a chemical penetration enhancer thiazone. We compared the re?ectance spectra of skin without laser irradiation or thiazone. Mono-treatment of thiazone could not signi?cantly enhance the optical clearing ef?cacy of the skin. After 60 min, the re?ectance spectrum decreased by only approximately 10%. With the combined treatment, the re?ectance spectrum decreased by approximately 30% after 10 min. Subsequently, the effect of laser dose on the enhancement of optical clearing ef?cacy was studied. The optimal irradiation dose was determined. The re?ectance of skins irradiated by a laser dose at 0.7 J/cm2 decreased by approximately 10% and were 20% lower than those at 0.5 and 0.9 J/cm2. The laser at 0.5 J/cm2 could not damage the SC completely, whereas the laser at 0.9 J/cm2 in?uenced the epidermis and dermis; thus, the re?ectance of skin samples irradiated by 0.9 J/cm2 did not decrease.
关键词： laser irradiation,tissue optical clearing technique,in vivo skin,optical clearing,thiazone,combined penetration enhancement
更新于2025-09-16 10:30:52
-
Laser adjuvant for vaccination
摘要： The use of an immunologic adjuvant to augment the immune response is essential for modern vaccines which are relatively ineffective on their own. In the past decade, researchers have been consistently reporting that skin treatment with a physical parameter, namely laser light, augments the immune response to vaccine and functions as an immunologic adjuvant. This “laser adjuvant” has numerous advantages over the conventional chemical or biological agents; it is free from cold chain storage, hypodermic needles, biohazardous sharp waste, irreversible formulation with vaccine antigen, undesirable biodistribution in vital organs, or unknown long-term toxicity. Since vaccine formulations are given to healthy populations, these characteristics render the “laser adjuvant” significant advantages for clinical use and open a new developmental path for a safe and effective vaccine. In addition, laser technology has been used in the clinic for more than three decades and is therefore technically matured and has been proved to be safe. Currently, four classes of laser adjuvant have been reported; ultrashort pulsed, non-pulsed, non-ablative fractional, and ablative fractional lasers. Since each class of the laser adjuvant shows a distinct mechanism of action, a proper choice is necessary to craft an effective vaccine formulation toward a desired clinical benefit for a clinical vaccine to maximize protection. In addition, data also suggest that further improvement in the efficacy is possible when a laser adjuvant is combined with chemical or biological adjuvant(s). To realize these goals, further efforts to uncover the molecular mechanisms of action of the laser adjuvants is warranted. This review provides a summary and comments of the recent updates in the laser adjuvant technology.
关键词： skin,vaccine,adjuvant,laser
更新于2025-09-16 10:30:52
-
Fractional 1,927?nm Thulium Laser Plus Photodynamic Therapy Compared and Combined for Photodamaged Décolleté Skin: A Side‐by‐Side Randomized Controlled Trial
摘要： Background and Objectives: Décolleté photodamage is a common condition typically treated with light and energy‐based devices. This study investigated the efficacy and safety of a fractional 1,927 nm thulium laser (TL) alone and combined with photodynamic therapy (PDT). Study Design/Materials and Methods: In a 12‐week follow‐up study, participant décolletés were divided into four treatment areas and randomized to receive a single treatment with field‐directed TL, PDT, combination TL‐PDT, or lesion‐directed curettage control. All actinic keratoses (AKs) underwent lesion‐directed curettage before randomization. TL was delivered at 20 mJ/mb, 500 mJ/cm2 fluence, 5 W, and 8 (n = 6 pts.) or 16 (n = 6 pts.) passes. PDT was performed with 16% methyl aminolevulinate (MAL) creme incubated for 3 h, followed by red light‐emitting diode light at 37 J/cm2. Outcome measures included clinical assessment of overall photodamage and specific subcomponents, assisted by optical coherence tomography (OCT) imaging. Results: Twelve women with moderate to severe photodamage on the décolleté and a cumulative total of 184 thin grade I AKs were included. Field‐directed treatments TL and combination TL‐PDT equally improved the overall photodamage, mottled pigmentation, and rhytides compared with lesion‐directed control (P < 0.05). The skin texture improved by TL alone and was further improved by combining TL and PDT (P < 0.05). Median AK complete responses were similar for field‐directed interventions TL‐PDT (100%), TL (90%), PDT (82%), and lesion‐directed curettage control (52%) (P = 0.464). Patients presented with mild local skin responses, slightly more pronounced when combining TL with PDT versus individual treatments (P < 0.05). No scarring or adverse events were observed. Conclusions: The 1,927 nm fractional thulium laser is an effective, tolerable, and safe field‐directed treatment for décolleté photodamage. Provided alone, TL proved to be as effective as combined TL‐PDT for overall photodamage, while a greater improvement in skin texture was achieved using TL and PDT in combination.
关键词： décolleté,optical coherence tomography,skin photodamage,thulium laser,non‐ablative laser,actinic keratosis,skin rejuvenation,photodynamic therapy
更新于2025-09-12 10:27:22
-
Treatment of Post‐Inflammatory Hyperpigmentation in Patients With Darker Skin Types Using a Low Energy 1,927?nm Non‐Ablative Fractional Laser: A Retrospective Photographic Review Analysis
摘要： Post inflammatory hyperpigmentation (PIH) can be difficult to treat especially in patients with darker skin types as darker skin carries increased epidermal melanin content. Various treatments available to improve the appearance of PIH may incite further pigmentation thus making treatment extremely difficult and frustrating. The purpose of this study was to perform a retrospective chart and photographic review to evaluate the efficacy and safety profile of a low energy low density non‐ablative fractional1927 nm wavelength laser treatment for PIH in patients with Fitzpatrick skin types IV‐VI. A retrospective evaluation of 61 patients with PIH treated with a 1927 nm laser was conducted at a single center. Inclusion criteria required at least 2 treatment sessions so that before and after treatment photographs would be available for comparison and study purposes. Two blinded physician‐evaluators using a visual analog scale for percentage of pigmentary clearance in standard photographs assessed treatment efficacy. The mean percent improvement after treatment, evaluated by two dermatologists was 43.24%. The correlation between raters was statistically significant (Pearson’s correlation coefficienct of r = 0.59, p < 0.0001). No side effects were observed in the patients treated with the 1927 nm laser. The low energy low density non‐ablative fractional 1927 nm wavelength laser is a safe and effective modality for improving post inflammatory hyperpigmentation in patients with darker skin types.
关键词： post‐inflammatory hyperpigmentation,skin of color,laser,dyschromia,darker skin types,discoloration
更新于2025-09-12 10:27:22
-
Characterization and validation of an in vivo confocal Raman spectroscopy led tri‐method approach in the evaluation of the lip barrier
摘要： Background/Aim: It was the aim to establish and validate in vivo confocal Raman spectroscopy for characterization of the lip barrier in conjunction with transepidermal water loss (TEWL) and skin capacitance assessments. For the first time in vivo, barrier-relevant components of the lip (derived, natural moisturizing factors (NMFs) and ceramides are described. Methods: In 32 healthy volunteers, a dental tongue fixation device was inserted to prevent both voluntary and involuntary lip moisturization during measurements. Seventeen individual parameters relating to water, ceramide, and NMF content were assessed via Raman spectroscopy. Additionally, corneometry and TEWL were measured. To give a guidance for the required volunteer group size of future lip barrier studies for all test parameters, coefficients of variation (CV) were calculated and plots showing the required sample size for a given percentage treatment effect. Results: Raman spectroscopy assessed parameters on the lower lip comprehensively characterized the state of the lip barrier. Parameter variability was sufficiently low to corroborate changes in most parameters using relatively small study populations. Conclusions: Lip skin is comparatively well hydrated. Biophysical measurement of the lip barrier function is a challenge, as unconscious licking of the lower lip has to be prevented. In vivo confocal Raman spectroscopy provides insightful parameters for the characterization of the lip barrier and sufficiently low inter-individual variability to assess relatively small parameter changes employing relatively few study subjects. Differences at the molecular level and at a high spatial resolution are detectable, and these insights might provide a breakthrough in the evaluation of lip barrier function and developing solutions for lip care.
关键词： lip skin measurements,closed chamber transepidermal water loss,lip stratum corneum,skin hydration capacitance,Raman spectroscopy
更新于2025-09-12 10:27:22