Lasers in veterinary medicine—where have we been, and where are we going? (original) (raw)
Related papers
Reports on Progress in Physics, 2008
It is hard to imagine that a narrow, one-way, coherent, moving, amplified beam of light fired by excited atoms is powerful enough to slice through steel. In 1917, Albert Einstein speculated that under certain conditions atoms could absorb light and be stimulated to shed their borrowed energy. Charles Townes coined the term laser (light amplification by stimulated emission of radiation) in 1951. Theodore Maiman investigated the glare of a flash lamp in a rod of synthetic ruby, creating the first human-made laser in 1960. The laser involves exciting atoms and passing them through a medium such as crystal, gas or liquid. As the cascade of photon energy sweeps through the medium, bouncing off mirrors, it is reflected back and forth, and gains energy to produce a high wattage beam of light. Although lasers are today used by a large variety of professions, one of the most meaningful applications of laser technology has been through its use in medicine. Being faster and less invasive with a high precision, lasers have penetrated into most medical disciplines during the last half century including dermatology, ophthalmology, dentistry, otolaryngology, gastroenterology, urology, gynaecology, cardiology, neurosurgery and orthopaedics. In many ways the laser has revolutionized the diagnosis and treatment of a disease. As a surgical tool the laser is capable of three basic functions. When focused on a point it can cauterize deeply as it cuts, reducing the surgical trauma caused by a knife. It can vaporize the surface of a tissue. Or, through optical fibres, it can permit a doctor to see inside the body. Lasers have also become an indispensable tool in biological applications from high-resolution microscopy to subcellular nanosurgery. Indeed, medical lasers are a prime example of how the movement of an idea can truly change the medical world. This review will survey various applications of lasers in medicine including four major categories: types of lasers, laser-tissue interactions, therapeutics and diagnostics.
Medical Applications of Laser Instruments
This paper gives the explanation of different medical applications of LASER instruments in detail. This paper discusses their working principles along with their advantages and limitations. These instruments nowadays are excessively used, and it has made surgery easier. They are used in treatment of cancer, removal of tumors of vocal cords, brain surgery, plastic surgery, gynecology and oncology, etc.
Non-PDT Uses of lasers in oncology
Lasers In Medical Science, 1995
The use of therapeutic lasers depends on four basic laser-tissue interactions; photothermal, photochemical (PDT), mechanical and ablative. There is no place for mechanical and ablative interactions in oncology; PDT will be the subject of a further review and the subject of this review is therefore the photothermal reaction. Thermal lasers have been in routine use in oncology for the last 10-15 years. These lasers, emitting in the visible or infra-red parts of the spectrum, are used to produce three basic effects; hyperthermia, coagulation and vaporization. Other energy sources beside lasers can also be used to produce these tissue effects but lasers seem to possess certain basic advantages. In comparison with monopolar or bipolar diathermy and heater probes, lasers can deliver more power, more accurately at the target tissue with better control of damage and a wider range of effects. In comparison with microwave and ultrasound therapy, lasers are again more precise and can be used with more compact and accurate delivery devices. In gastroenterological surgery (as opposed to endoscopy), neurosurgery and gynaecology, laser light can be delivered via a handpiece to cut and coagulate. In ENT and also some applications of gynaecology lasers can also be used via a microscope. In endoscopic surgery laser light is delivered through an optical fibre within the endoscope-this for the time being precludes the use of the CO 2 laser for these applicati6ris. More recently, the laser fibre can be placed directly within tumour tissue for interstitial thermal therapy of liver metastases, pancreatic tumours and brain tumours. The future use of thermal lasers in oncology depends very much on the results of properly controlled comparative studies against PDT and non-laser thermal devices; in addition their use may well be widened to include some curative procedures; up until now their use has very much been restricted to palliative therapy except where they are used as an adjunctive cutting device alongside conventional curative surgery.
Lasers in Veterinary Dermatology
Veterinary Clinics of North America: Small Animal Practice, 2006
HISTORY OF LASERS Laser is an acronym that means light amplification by stimulated emission of radiation [1]. The stimulated emission of light and its properties was first described in the early 1900s by Einstein. Forty years later (in 1960), the first laser was developed at Bell Laboratories, and during the 1970s, lasers were introduced for use in medicine. Over the next decade, smaller and less expensive lasers were introduced and their use in medicine expanded. By late 1980s, many different types of lasers had been developed and were being used by many medical specialties, including veterinary medicine [2-8]. HOW LASERS WORK Lasers are devices that generate electromagnetic radiation that is essentially monochromatic, a single wavelength, and can be compressed into a small beam that is able to travel wide distances with little divergence. Lasers produce a high-intensity beam so intense that their light is 10 times brighter than the sun [9]. The lasers in use for medical purposes are referred to as light lasers. Light, by definition, is that portion of the electromagnetic spectrum that is visible to the human eye; however, lasers in use in medicine emit beams of radiation that are in the visible range as well as in the near-infrared or ultraviolet regions. These beams behave in the same way as the visible spectrum in that they can be focused with lenses and reflected with mirrors; thus, for simplicity, they are called light lasers [7]. Lasers are named for the medium that is used to produce the laser light beam. Each laser's properties depend on the medium used to produce the laser beam and the ways in which that beam is delivered. The laser beam's interaction with tissue depends on the wavelength, power, and time that the beam is exposed to the tissue [4]. Some lasers, for example, the Qswitched ruby laser, do not interact with the surface tissue but penetrate deeper to interact with pigmented or vascular targets, such as pigmented nevi, tattoos, or vascular lesions.
Mechanisms of Laser-Tissue Interaction: I. Optical Properties of Tissue
Today, lasers are widely used in biology and medicine, and the majority of health centers and hospitals utilize modern laser systems for diagnosis and therapy applications. Researchers have introduced different medical applications for different lasers used in surgeries and other medical treatments. Medical lasers can be categorized in both diagnosis and therapy branches. Main difference between diagnosis and therapy applications is the type of laser-tissue interactions. In diagnosis, one tries to arrange a noninvasive method to study the normal behavior of tissue without any damage or clear effect on tissue. But in therapy, such as surgery, a surgeon uses laser as a knife or for affecting a specific region. So, the medical laser applications are defined by the interaction type between laser light and tissues. The knowledge of laser-tissue interaction can help doctors or surgeons to select the optimal laser systems and modify the type of their therapy. Therefore, we seek to review t...
Four different diode lasers comparison on soft tissues surgery: a preliminary ex vivo study
LASER THERAPY, 2016
The introduction of diode lasers in dentistry had several advantages, principally consisting on the reduced size, reduced cost and possibility to beam delivering by optical fibbers. Up today only the wavelengths around 810 and 980 nm were the most utilized in oral surgery but recently more different lasers had been proposed. The aim of this study was to compare the efficacy of four diode laser wavelengths (810, 980, 1470 and 1950 nm) for the ablation of soft tissues. Material and methods: Specimens were surgically collected from the dorsal surface of four bovine tongues and irradiated by four different diode wavelengths. Thermal increase was measured by two thermocouples, the first at a depth of 0.5 mm, and the second at a depth of 2 mm. Initial and final surface temperatures were recorded by IR thermometer. Epithelial changes, connective tissue modifications, presence of vascular modification and incision morphology were histologically evaluated by two blind pathologists. Results: The time necessary to perform the excision varied between 271 seconds (808 nm, 2W) and 112 seconds (1950 nm, 4W). Temperature increase superficial level varied from 16.3° (980 nm, 4W) and 9.2° (1950 nm, 2 W). The most significant deep temperature increase was recorded by 980 nm, 4 W (17.3°) and the lowest by 1950 nm, 2 W (9.7°). The width of epithelial tissue injuries varied between 74 µm from 1950 nm diode laser at 2 W to 540 µm for 1470 nm diode laser at 4 W. Conclusion: The quality of incision was better and the width of overall tissue injuries was minor in the specimens obtained with higher wavelength (1950 nm) at lower power (2W).
Medical Lasers and Their Safe Use
Springer eBooks, 1993
Library of Congress Cataloging-in-Publication Data Sliney, David H. Medical lasers and their safe uselDavid H. Sliney, Stephen L. Trokel. p. cm. Includes bibliographical references and index.