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Thermal Imager Fundamentals
Published in James Stewart Campbell, M. Nathaniel Mead, Human Medical Thermography, 2023
James Stewart Campbell, M. Nathaniel Mead
Automatic focus is highly recommended for producing sharp, clear, and calibrated thermal images. When using a laser focusing mechanism, care should be exercised to avoid directing the light beam into the subject's eyes. Direct the laser toward the forehead or chin when imaging the face. When using laser focus, carefully observe the laser beam on the ROI to be sure the correct area is being measured, not the wall behind. A laser focusing beam is not visible in the thermal image, but it can be seen on the visible-band camera in the imager, if so equipped, or by directly observing the subject. The autofocus feature is useful for documenting the focus distance in a report. The autofocus distance is often stated in the image metadata. Documented distance measurements are useful to assure consistent repeat images of a subject.
Treatment
Published in William Bonnez, Guide to Genital HPV Diseases and Prevention, 2019
Lasers produce a high-energy, collimated light beam. This light is monochromatic and the wavelength determines the specific medical application. The CO2 laser is the instrument of choice for the treatment of mucoso-genital lesion because its infrared light (λ = 10,600 nm) vaporizes the intratissular water. By varying the focus of the beam the operator can either cut or vaporize the lesions. Further control is applied on how the light is emitted, either continuously or intermittently. Operator skill is important and undoubtedly contributes to the varying outcomes that have been reported in uncontrolled studies. Laser surgery is applicable to the treatment of external and internal anogenital warts—including during pregnancy—intraepithelial neoplasias, especially of the cervix, and recurrent respiratory papillomatosis. Pain is significant and local, sometimes general, anesthesia is necessary. The EMLA cream is an effective topical anesthetic for laser surgery. Up to a quarter of patients experience pain, bleeding, swelling, and scarring after the procedure.
Proton Accelerators
Published in Harald Paganetti, Proton Therapy Physics, 2018
When the light beam from a very high-power laser hits a target, protons will be emitted from the target. For proton therapy, this can be of interest since the laser and light transmission components do not need heavy concrete shielding. Further, heavy and big magnets are not needed anymore. Also, scanning the light beam could be used for pencil beam scanning in principle. These ideas are illustrated in Figure 3.27 [67].
Solanaceae glycoalkaloids: α-solanine and α-chaconine modify the cardioinhibitory activity of verapamil
Published in Pharmaceutical Biology, 2022
Szymon Chowański, Magdalena Winkiel, Monika Szymczak-Cendlak, Paweł Marciniak, Dominika Mańczak, Karolina Walkowiak-Nowicka, Marta Spochacz, Sabino A. Bufo, Laura Scrano, Zbigniew Adamski
A microdensitometric method, described previously (Marciniak et al. 2008; Chowański and Rosiński 2017; Chowański et al. 2017; Pacholska-Bogalska et al. 2018), was used to analyse the cardiotropic effects of the compounds tested. It allows the measurement of the heart contraction frequency of a semi-isolated heart in insects. Briefly, this method uses a light beam that passes through the myocardium. The density of the tissue changes temporally during the heart cycle, increasing during contraction and decreasing during relaxation. Thus, the amount of light that passes through the myocardium also changes. The intensity of the light beam transmitted through the myocardium is recorded by photodiodes and converted into an electrical signal presented as a cardiomyogram. The signal is registered and converted with LARWA software designed in our department. The experiments were conducted on a semi-isolated heart, the preparation of which is described above. A semi-isolated heart was placed in an incubation chamber and perfused with saline at a flow rate of 300 μL/min. After 5 min of preincubation, registration was started, and the signal was recorded for 22 min. During that time, the preparation was perfused with saline or various solutions of the tested compounds.
Comparison of Two Spectral-domain Optical Coherence Tomography Scan Modes for Measuring Retinal Vessel Diameter
Published in Current Eye Research, 2021
Wei Lou, Weelic Chong, Hongyu Kong, Wei Du, Jun Zhou, Xueyan Zhang, Hanyan Tao, Qiang Wu
There are intrinsic differences between circular and raster scans. One difference relates to the path of the light beam. Theoretically, the OCT scan beam should be perpendicular to the vessel, resulting in a scan depicting a vessel as four hyperreflectivities surrounded by a perfectly round contour. However, in our experience this ideal representation does not always occur, and we often identify the four hyperreflectivities without a round contour. We speculate that this means that the scan beam is not perpendicular to the vessel and thus may measure the diameter at an oblique angle, resulting in a slight bias. This may pose difficulty when comparing different types of scans, especially if the scan beam is perpendicular more often for one scan mode than another. We would require a deeper understanding of the optics that underlie different scan modes in order to study this further.19
The “in’s and outs” of laser hair removal: a mini review
Published in Journal of Cosmetic and Laser Therapy, 2019
Mandy M. Thomas, Nicolette N. Houreld
The IPL system delivers a broad range of non-coherent light in the spectrum of 400 nm to 1400 nm. The larger spot sizes associated with most IPL hand pieces allows for a larger target area, and thus a large amount of hair to be treated simultaneously. The light beam is delivered to the skin through a quartz or sapphire light guide and a translucent cooling gel is topically applied prior to the treatment. Szima et al. (19), conducted a study on 38 untanned volunteers with Fitzpatrick skin types II to III, and brown or black terminal hair. Patients underwent seven treatment sessions on the leg at 4- to 6-week intervals, with a 6- and 18-month follow-up. Unwanted leg hair was decreased safely and efficiently by both systems; however, IPL had less side effects and higher satisfaction scores.