Biological Effects of Laser Radiation

Fine, Susan B.; Klein, Edmund

doi:10.1016/b978-0-12-005210-3.50007-x

Cited by 26 publications

(2 citation statements)

References 101 publications

(69 reference statements)

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“…The use of lasers in surgery began only a couple years after the advent of the laser in 1959 where initial experiments by M. Zaret et al demonstrated promising results in ophthalmological procedures [22]. The same cannot be said for use in neurosurgical procedures as the first application of ruby laser to murine cranium by Earle et al [23] and Fine et al [24] in 1965 resulted in instant death due to brain stem compression. Generally, use of the ruby laser in neurological procedures was not promising at the time given the poor absorption of the laser by non-pigmented tissues and uncontrollable biomechanical effects [25].…”

Section: Lasers In Neurosurgerymentioning

confidence: 99%

Optical Coherence Tomography for the Evaluation of Energy Seals and the Subsequent Evaluation of the Thulium Laser as a Hemostatic Instrument

Marques¹

2021

Preprint

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This thesis presents the development of a system which integrates both an Optical Coherence Tomography system and a high-powered Thulium fiber laser. The system was developed in order to study the interaction between Thulium laser and tissue via Optical Coherence Tomography feedback. This was done given the Thulium laser’s theoretical potential to serve as a multipurpose surgical instrument. The core work of the thesis is divided into two sections: <div>1. The development of an energy seal evaluation methodology using Optical Coherence Tomography. One-hundred and four avian embryonic vessels were subjected to Thulium laser irradiation at 1942 nm and subsequently imaged. Using both structural and Doppler feedback, several biomarkers were identified and used to classify irradiation outcomes as sealed or not sealed. The methodology developed here was compared to visual methodologies. It was found that the reported seal rate was dependent on the classification methodology (p = 0.01) where visual evaluation reported 18% more seals across the entire data set. The specificity of visual evaluation was dependent on the type of non-seal classification (p < 0.0001). Given that the developed methodology relied on the identification of biomarkers rather than user opinion, an objective evaluation methodology was achieved. Hemostatic systems evaluated visually should be re-evaluated. </div><div>2. Evaluating the Thulium laser as a hemostatic instrument. Average power, exposure time, and spot size were varied to maximize the seal rate. At sub 2 s exposure times the overall seal rate across all vessels was 29%. The highest seal rate achieved for a single condition was 60%. The rupture rate showed some correlation to average power.<div>Biological factors were found to have a significant effect on the seal rate where the mean vessel diameter for non-seal outcomes was greater than that for seal outcomes </div><div>(p < 0.001). Tissue dehydration was a factor in this study. The average heat affected zone was 2.2 ± 1.1 mm, typical of a hydrolytic laser. This finding affirmed that hydrolytic lasers can induce seals despite the dimensions of the optical zone. As irradiance increased so did the heat affected zone, the opposite was true for exposure time. Using a dose until seal approach the seal rate was 95% across 18 vessels. The average therapeutic time was 9 ± 3 s for single vessel. Based on the overall lack of predictability observed in interactions between Thulium laser and vascular tissue, as well as the relatively poor seal rates, the Thulium laser was not recommended to be used in hemostatic applications. </div></div>

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Section: Lasers In Neurosurgerymentioning

confidence: 99%

Optical Coherence Tomography for the Evaluation of Energy Seals and the Subsequent Evaluation of the Thulium Laser as a Hemostatic Instrument

Marques¹

2021

Preprint

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“…If the medium is isotropic and static, then the object is in a state of rest or uniform motion. When the environment is excited, the coordinates of the object in space are violated TECHNOLOGY AUDIT AND PRODUCTION RESERVES -№ 6/2(56), 2020 ISSN 2664-9969 and, accordingly, it creates new energetic forces for the corresponding rest in space [4,5].…”

Section: Introductionmentioning

confidence: 99%

Justification of the principles of coordinate theory based on the D'alembert’s principle and small movements

Skytsiouk¹,

Ivanenko²

2020

TAPR

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The work is a continuation of a number of author's studies devoted to the accuracy of determining the coordinates of an abstract object in technological space. So, since any object is in two coordinate systems, there is a problem of compatibility of these systems. It is this compatibility of coordinate systems that causes stability of motion and location of an abstract object in space. Now the stability of the movement or location of an object in space is taken as its frame of reference, that is, the zero point of any device or object. This is especially true for machine tools with numerical control (CNC). In order to solve the problem of compatibility of the coordinate system of the machine and the part, it is necessary to create a basic theory of coordinates, which will solve the problems of coordinating coordinate systems. The presence of an imaginary coordinate system in the CNC memory and the process of its implementation in a real machine coordinate system are shown. There is a need to investigate the physical and mathematical properties of a point, a dash, an error field structure and the relationship between all these field elements. The research proposed by the authors is devoted to the interpretation of ordinary natural phenomena by the physicochemical laws of interaction between abstract entities. Thus, the object of research is the relationship between imaginary and real coordinates. One of the most problematic places is the spatial reference of abstract space, that is, functional movement or stationary state. Analytical studies based on field affine transformations are used in this research. As a result, the possibility of creating a theory of coordinates of abstract objects in general, regardless of their physicochemical and medico-biological properties, has been theoretically substantiated. So, if to consider the processes of interaction between abstract objects, then it is possible to state the fact that such interaction has a very specific character. As a result, let's obtain a lot of sciences that give a similar description of the processes around us and their branches. It should be emphasized that there is a fairly clear distinction between the main scientific areas at the initial stage. The research carried out is useful in the development of metrological instruments and standard measuring instruments in assessing their stability.

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