scholarly journals Interferometric imaging of thermal expansion for temperature control in retinal laser therapy

2022 ◽  
Author(s):  
David Veysset ◽  
Tong Ling ◽  
Yueming Zhuo ◽  
Vimal Pandiyan ◽  
Ramkumar Sabesan ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Laser Therapy ◽  
Temperature Control ◽  
Interferometric Imaging

scholarly journals Interferometric imaging of thermal expansion for temperature control in retinal laser therapy

2021 ◽  
Author(s):  
David Veysset ◽  
Tong Ling ◽  
Yueming Zhuo ◽  
Daniel Palanker
Keyword(s):  
Thermal Expansion ◽  
Laser Therapy ◽  
Temperature Rise ◽  
Path Length ◽  
Optical Path Length ◽  
Optical Path ◽  
Laser Exposure ◽  
Interferometric Imaging ◽  
Tissue Phantom ◽  
Length Changes

Precise control of the temperature rise is a prerequisite for proper photothermal therapy. In retinal laser therapy, the heat deposition is primarily governed by the melanin concentration, which can significantly vary across the retina and from patient to patient. In this work, we present a method for determining the optical and thermal properties of layered materials, directly applicable to the retina, using low-energy laser heating and phase-resolved optical coherence tomography (pOCT). The method is demonstrated on a polymer-based tissue phantom heated with a laser pulse focused onto an absorbing layer buried below the phantom's surface. Using a line-scan spectral-domain pOCT, optical path length changes induced by the thermal expansion were extracted from sequential B-scans. The material properties were then determined by matching the optical path length changes to a thermo-mechanical model developed for fast computation. This method determined the absorption coefficient with a precision of 2.5% and the temperature rise with a precision of about 0.2°C from a single laser exposure, while the peak did not exceed 8°C during 1 ms pulse, which is well within the tissue safety range and significantly more precise than other methods.

scholarly journals Modeling and Temperature Control of Retinal Laser Therapy

2020 ◽  
Vol 53 (2) ◽  
pp. 16451-16456
Author(s):  
Hossam S. Abbas ◽  
Christopher Kren ◽  
Veit Danicke ◽  
Dirk Theisen-Kunde ◽  
Ralf Brinkmann
Keyword(s):  
Laser Therapy ◽  
Temperature Control

In-Situ Temperature Control for Rtp Via Thermal Expansion Measurement

1993 ◽  
Vol 303 ◽  
Author(s):  
Bruce Peuse ◽  
Allan Rosekrans
Keyword(s):  
Thermal Expansion ◽  
Temperature Control ◽  
Measurement Technique ◽  
Preliminary Data ◽  
Thermal Processing ◽  
Rapid Thermal Processing ◽  
Processing System ◽  
Wafer Temperature ◽  
Thermal Expansion Measurement

ABSTRACTA new method of temperature control for rapid thermal processing of silicon wafers is presented whereby in-situ wafer temperature is determined by measurement of wafer thermal expansion via an optical micrometer mechanism. The expansion measurement technique and its implementation into a rapid thermal processing system for temperature control are described. Preliminary data show the wafer to wafer temperature repeatability to be 1% (3-σ) using this technique.

A High Angle, Double Tilting Cold Stage for the AEI EM7

1974 ◽  
Vol 32 ◽  
pp. 450-451
Author(s):  
P.R. Swann ◽  
A.E. Lloyd
Keyword(s):  
Habit Plane ◽  
Temperature Control ◽  
Tilt Angle ◽  
Cooling System ◽  
Thermal Drift ◽  
High Angle ◽  
Cold Stage ◽  
High Degree ◽  
Better Than

Figure 1 shows the design of a specimen stage used for the in situ observation of phase transformations in the temperature range between ambient and −160°C. The design has the following features a high degree of specimen stability during tilting linear tilt actuation about two orthogonal axes for accurate control of tilt angle read-out high angle tilt range for stereo work and habit plane determination simple, robust construction temperature control of better than ±0.5°C minimum thermal drift and transmission of vibration from the cooling system.

Microstructural and Microchemical Characterization of Nickel Sulfide Inclusions in Plate Glass

1991 ◽  
Vol 49 ◽  
pp. 962-963
Author(s):  
J. Cooper ◽  
O. Popoola ◽  
W. M. Kriven
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Glass Matrix ◽  
Nickel Sulfide ◽  
Plate Glass ◽  
Thermal Expansion Mismatch ◽  
Volume Increase ◽  
Β Phase ◽  
Microchemical Characterization

Nickel sulfide inclusions have been implicated in the spontaneous fracture of large windows of tempered plate glass. Two alternative explanations for the fracture-initiating behaviour of these inclusions have been proposed: (1) the volume increase which accompanies the α to β phase transformation in stoichiometric NiS, and (2) the thermal expansion mismatch between the nickel sulfide phases and the glass matrix. The microstructure and microchemistry of the small inclusions (80 to 250 μm spheres), needed to determine the cause of fracture, have not been well characterized hitherto. The aim of this communication is to report a detailed TEM and EDS study of the inclusions.

Special Articles?: Laser Therapy of the Skin: A Review of Principles and Applications

1990 ◽  
Vol 23 (1) ◽  
pp. 123-164 ◽  
Author(s):  
Philip L. Bailin ◽  
John L. Ratz ◽  
Ronald G. Wheeland
Keyword(s):  
Laser Therapy
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