Download or read book Ocular Effects of Repetitive Laser Pulses written by and published by . This book was released on 1972 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: An argon-ion laser was used to investigate the ocular effects of repetitive laser pulses on rhesus monkeys. The primate eyes were irradiated by trains of pulses held constant at 10 milliseconds, and the duration of the trains was kept uniform at 0.5 sec. The pulse repetition rate was used as a parameter and this parameter was varied to take on the values of 2 Hz(single pulse), 10 Hz, 100Hz, 1 kHz and 10 kHz. Retinal burn thresholds were determined based on the 1 hr criterion for the appearance of ophthalmoscopically visible lesions.
Download or read book High Resolution Imaging in Microscopy and Ophthalmology written by Josef F. Bille and published by Springer. This book was released on 2019-08-13 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book provides a comprehensive overview of the application of the newest laser and microscope/ophthalmoscope technology in the field of high resolution imaging in microscopy and ophthalmology. Starting by describing High-Resolution 3D Light Microscopy with STED and RESOLFT, the book goes on to cover retinal and anterior segment imaging and image-guided treatment and also discusses the development of adaptive optics in vision science and ophthalmology. Using an interdisciplinary approach, the reader will learn about the latest developments and most up to date technology in the field and how these translate to a medical setting. High Resolution Imaging in Microscopy and Ophthalmology – New Frontiers in Biomedical Optics has been written by leading experts in the field and offers insights on engineering, biology, and medicine, thus being a valuable addition for scientists, engineers, and clinicians with technical and medical interest who would like to understand the equipment, the applications and the medical/biological background. Lastly, this book is dedicated to the memory of Dr. Gerhard Zinser, co-founder of Heidelberg Engineering GmbH, a scientist, a husband, a brother, a colleague, and a friend.
Download or read book Effects on Ocular Tissue of Multiple Laser Pulses and of Single Ultrashort Pulses of Varying Wavelength written by and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to evaluate laser safety standards, Dr. Toth examined fluorescein angiograms (in some cases OCT) and fixed tissue sections and aided in defining exposure limits for pulse widths less than one nanosecond. In our initial short pulse study, we were concerned with the restriction to a single wavelength. To verify that the tissue effects were due to the pulse structure, we obtained data outside a single wavelength. We obtained from information from -530-nm and -1060nm wavelengths to compare to data obtained from previous studies of visible laser picosecond and femtosecond pulses. The type of lesions created with 530 and 1060-1064nm wavelengths were similar to the lesions created in the earlier 580-nm wavelength studies. This supported the theory that laser induced breakdown is one of the primary damage mechanisms for ultrashort laser pulses. Data from our studies was used by the American National Standard Institute in publications ANSI Z136.1, 'Safe Use of Lasers' (updated 2000) and ANSI Z136.3, 'Safe Use of Lasers in Health Care Facilities' (1996).
Download or read book Proceedings of Laser and Noncoherent Ocular Effects written by Society of Photo-optical Instrumentation Engineers and published by SPIE-International Society for Optical Engineering. This book was released on 1997 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser and Noncoherent Light Ocular Effects written by and published by . This book was released on 2003 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Safety with Lasers and Other Optical Sources written by D. H. Sliney and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 1042 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nearly a decade aga a general review article on the evaluation of optical radia tion hazards was published in Applied Optics (Sliney and Freasier, 1973). This arti cle received many favorable comments but also prompted many inquiries regarding specific optical hazard problems. From this it became evident that a monograph rather than a supplemental and expanded article was needed to fill this literature gap relating to laser and optical radiation hazards. The present work is designed to fill that gap, and is structured to permit either classroom or self-study use. Much of the material in this book was developed in eonnection with short courses on laser safety and radiometry in which we have participated, as weIl as from our previous articles. In particular, the sequenee of chapters is based upon the experiences which we have had in lecturing in courses with different schedules. One of the great difficulties in developing a text of this nature is that a broad, multidisciplinary background must be included in order that the reader can comprehend all of the subjeet matter readily. For this reason, the material presented on anatomy and physiology is orien ted toward the engineer or physical scientist, while the review material on basic optical physics is intended more for the physician or life scientist.
Download or read book Ocular Hazards of Picosecond and Repetitive Pulsed Lasers Volume II Argon Ion Laser 514 5 Nm written by J. S. Connolly and published by . This book was released on 1978 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: Retinal damage thresholds were determined for exposures of the maculae of rhesus monkeys to CW and repetitive-pulse trains of argon-ion laser radiation at 514.5 nm in the TEMoo mode. Single-pulse exposures were made at pulsewidths of 2, 10, 40, and 100 microsec and 1, 10, 100, and 500 msec. Repetitive-pulse exposures were made for 27 different combinations: train durations of 0.05, 0.5, 5, and 30 sec; pulse repetition frequencies from 0.10 Hz to 10 kHz and pulsewidths of 10, 40, and 100 microsec and 1 msec. Damage thresholds for mode-locked argon laser pulses at 104 MHz and 250 psec pulsewidth for pulse trains of 9.9-sec, 10-msec, and 10-microsec duration were also measured. For pulsewidths of 10 microsec, there is an apparent cumulative effect provided the repetition frequencies are in the range of approximately 0.1 to approximately 10 Hz. The retina is more sensitive to double-pulse exposures, by a factor of 2 to 3 relative to single-pulse thresholds, when the interpulse spacing is approximately 2.5 sec. Nonthermal damage mechanisms, involving a two-step, two-threshold process, may explain our results. Specifically, for double-pulse configurations, the first acts as a reversible photo-trigger which sensitizes the retina in preparation for the subsequent pulse. The elements of an empirical model have been assembled and appear to account satisfactorily for the observed double-pulse threshold data. (Author).
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ocular Damage Thresholds for Repetitive Pulsed Argon Laser Exposure written by William D. Gibbons and published by . This book was released on 1974 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The maculae of rhesus monkeys were exposed to radiation from an argon-ion laser operated at a wavelength of 514.5 nm in the TEMoo mode. Damage thresholds were determined for exposure to a single 40 microsec pulse and for different pulse train lengths and repetition rates of 40 microsec wide repetitive pulses. The single pulse threshold was determined to be 2.0 micro J. Thresholds for repetition rates of 100 and 1000 Hz at a pulse train length of 0.5 sec were both found to be 1.0 micro J per pulse. Exposures made at a repetition rate of 100 Hz for pulse train durations of 0.1 and 1.0 sec yielded thresholds of 2.0 and 0.4 micro J per pulse. These data indicate that pulse train length has a greater effect on threshold than repetition rate for the range of parameters studied. (Author).
Download or read book Ultrashort Laser Pulse Effects in Ocular and Related Media Laser Induced Shock Wave Propagation and Retinal Damage written by T. F. Deutsch and published by . This book was released on 1994 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goals of this project are: (1) To develop assays for functional damage to retinal cells by pressure waves (stress transients); (2) To determine the acoustic properties of the aqueous and vitreous humors of the eye; and (3) To examine the effect of pressure waves to the retinal pigment epithelium in vitro. During this first year our efforts have been directed primarily at the first goal, with some initial efforts on the second. During this period we developed the capability of growing human retinal pigment epithelium (RPE) cells in culture, incorporating them intest capillaries, recovering them after exposure to stress transients and assessing cell damage.
Download or read book Ultrashort Laser Pulse Effects on Ocular Tissue Histopathologic Analysis and Surgical Techniques written by Cynthia Toth and published by . This book was released on 1998 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Toth et al. identified the acute pathologic retinal events which determined the extent of tissue damage from minimal laser energy and suprathreshold energy. She identified the acute pathology of primate maculas with minimal visible retinal lesions generated by 90 femtosecond and 5 picosecond pulses of 580 nm laser energy. Dr. Toth's study included light microscopic evaluation of macular damage and electron microscopic ultrastructural analysis of melanosome ruptures within the retinal pigment epithelium. The pathology was reported at AFOSR with a CDROM summary of lesion data provided to armstrong Laboratory for reference. Dr. Toth scored the area and extent of tissue damage and compiled a list for Dr. Rockwell and Dr. Clarence Cain at Armstrong Laboratory, Brooks, AFB for analysis and comparison to the ED50 MVL data. A paper summarizing this work has been published as the lead article in October, 1997 in Investigative Ophthalmology and Visual Science (I0VS). Dr. Toth's Laboratory group gathered significant tissue data on ultrashort pulses of other laser wavelengths. They collaborated with Armstrong Laboratory (Dr. Cain et al.) in analyzing near-infrared ultrashort laser pulse injury MVL data which was published at Society of Photo-Optical Instrumentation Engineers (SPIE), 1997 (Cain, Toth, et al.).
Download or read book Ocular Hazards of Picosecond and Repetitive Pulsed Lasers Volume I Nd YAG Laser 1064 Nm written by H. W Hemstreet (Jr) and published by . This book was released on 1978 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: Retinal damage thresholds are discussed for exposure of rhesus maculae to continuous wave and repetitive-pulse trains of 1064-nm Nd:YAG laser radiation. For all single-pulse exposures and for repetitive pulses contained within a 0.05-sec train, retinal damage appears to be induced primarily by thermal mechanisms. For the longer pulse-train durations, a cumulative effect is apparent when the repetition frequencies are in the range of>1 to
Download or read book Administracion del general don Juan Antonio Pezet la republica del P ru written by and published by . This book was released on 1867 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ocular Effects of Near Infrared Laser Radiation for Safety Criteria written by and published by . This book was released on 1972 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ocular effects of near infrared laser radiation were studied using a Nd3+ - YAG laser which emitted light at a wavelength of 1060 nm in the TEM00 mode. Retinal burn data were obtained on rhesus monkey eyes with the exposure duration used as a parameter. The exposures were for 1 sec, .1 sec, .01 sec, . 001 sec and .0000001 sec durations and for trains of the .0000001 sec pulses with a pulse repetition rate of lkHz lasting for 0.5 sec. Thirty eyes were irradiated for each exposure duration. The data were analyzed to find the energy per pulse corresponding to the retinal burn probability P=0.5 using (1) a probit analysis and (2) a straightforward arithmetical averaging of the retinal burn thresholds obtained for each eye.
Download or read book Selected Papers on Ultrashort Laser Pulse Bioeffects written by William P. Roach and published by SPIE-International Society for Optical Engineering. This book was released on 2002-12-31 with total page 694 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains key papers that document the initial probing of the limits of subnanosecond pulses and the resulting discoveries of nonlinear effects. The papers tell the story of effects previously thought to be impossible to produce in tissue. If you read all the references carefully, you will see the studies evolve from speculation to experimentation to theory, and culminate in policy recommendations.
Download or read book Lasers in Ophthalmology written by Franz Fankhauser and published by Kugler Publications. This book was released on 2003 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: Overview of the status of the broad range of laser applications.
Download or read book Ultrashort Pulse Laser Effects in the Primate Eye written by and published by . This book was released on 1994 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: Minimum visible lesion (MVL) threshold measurements at the retina for rhesus monkey eyes are reported for femtosecond, picosecond, and nanosecond single laser pulses using visible wavelengths. Estimates of the dose causing 50% probability for damage (ED50) are calculated for 1-hour and 24-hours postexposure as well as the 95% fiducial intervals for ED. The ED values are found to be dependent on both wavelength and pulsewidth, and for a single wavelength are, in general, lower for short pulsewidths, with the exception of values at the shortest pulsewidth of 90 fs at 580 nm. At 90 fs the ED(50) dosages were noted to increase slightly when compared with the 3-ps and 600-fs values, all three delivered at 580-nm wavelength. The 4-ns ED(50) value was more than double the value at 60 ps delivered at 532-nm wavelength. Fluorescein angiography was accomplished at 1-hour and 24-hours postexposure and did not demonstrate lower threshold for damage, which has been the case for MVLs created with longer pulse duration (greater than 1 ns) or for rabbit eyes at the same pulse-widths as measured in our laboratory.
