Few data are available about temperature distribution in tissue during Nd:YAG laser irradiation. To study the heat distribution that produces tissue coagulation, we used a thermographic camera aimed orthogonally to the laser beam axis to obtain thermal maps. Immediately after surgical resection, specimens of human stomach were irradiated near the resected edge, and the heat emitted sideways was detected by an infrared image system. A magnifying lens mounted on the camera enabled us to obtain 0.1 mm spatial resolution of the isothermic curves. The thermal analysis showed that the maximum depth where the increase in temperature reached 25 degrees C (corresponding to a coagulation temperature of about 60 degrees C) was never greater than 3 mm, irrespective of the power and exposure time used. Moreover, the bidimensional thermal maps showed that the temperature did not decrease in a purely exponential fashion along the beam axis, but reached a maximum at about 1 mm beneath the surface. This fact, which confirms the decrepitation theorem, could explain the explosion inside the tissues observed in surgical application of the Nd:YAG laser.

Download full-text PDF

Source
http://dx.doi.org/10.1002/lsm.1900050202DOI Listing

Publication Analysis

Top Keywords

ndyag laser
12
tissue ndyag
8
laser irradiation
8
beam axis
8
thermal maps
8
temperature
5
temperature rise
4
rise biological
4
biological tissue
4
laser
4

Similar Publications

Treatment of onychomycosis includes topical and systemic agents. However, prolonged use of oral treatment could cause adverse effects and topical antifungal agents have limited penetration. To compare the clinical efficacy and the safety of fractional CO laser combined with topical tioconazole nail solution versus Q-switched 1064 Nd: YAG laser in the treatment of fingernail onychomycosis.

View Article and Find Full Text PDF
Article Synopsis
  • Melasma is a common, chronic skin condition that mainly affects women, presenting as dark patches on the face and is often perceived as a serious cosmetic issue.
  • A survey conducted among 199 dermatologists in Turkiye revealed that the majority of patients with melasma are females between the ages of 30 to 40, with mixed melasma being the most common type.
  • The study found that topical treatments, particularly Kligman's formula, are most frequently used, while oral treatments like tranexamic acid are less common, and there's a significant recurrence rate of 41%-60%, suggesting the need for better management strategies.
View Article and Find Full Text PDF

Anion photoelectron spectra of ThSO- and ThS2- were recorded using the third (355 nm) harmonic of an Nd-YAG laser; these provided the measured vertical detachment energies of each anion. The experiments are supported by extensive coupled cluster calculations on ThSO, ThSO-, ThS2, and ThS2-, as well as the oxygen congeners ThO2 and ThO2-. The ab initio calculations, which included complete basis set extrapolations, spin-orbit effects using four-component coupled cluster, and higher-order correlation contributions through CCSDT(Q), yielded an adiabatic electron affinity for ThO2 that was within 0.

View Article and Find Full Text PDF

Plasma focus devices represent a class of hot and dense plasma sources that serve a dual role in fundamental plasma research and practical applications. These devices allow the observation of various phenomena, including the z-pinch effect, nuclear fusion reactions, plasma filaments, bursts, shocks, jets, X-rays, neutron pulses, ions, and electron beams. In recent years, considerable efforts have been directed toward miniaturizing plasma focus devices, driven by the pursuit of both basic studies and technological advancements.

View Article and Find Full Text PDF
Article Synopsis
  • The study looked at the risks of retinal detachment (RD) after a specific eye surgery called Boston Type 1 Keratoprosthesis (B1KPro) during the first year and beyond.
  • They found that 29% of patients experienced RD, with most cases happening within the first year (21%) and fewer later (7%).
  • Important risk factors for early RD included low eye pressure (hypotony), previous eye surgeries, and certain eye conditions, while changes in the retina before surgery were linked to later RD.
View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!