In the present work, we simulate the flying-spot laser delivery device utilized in a typical LASIK procedure via a simple, low cost, safe and representative optical prototype suitable for education and training purposes.
We present a simple computerized tool for training on practicing common laser skin treatments. The device is proposed to enhance operator’s technical skills and increase his proficiency via detecting overlap percentage of the laser spots.
Optical diagnostics and imaging techniques have been widely spread in various biomedical and clinical applications. Although these techniques have the advantages of being safe and functional, most of them still suffer from relatively low resolution. The optical scattering and absorption properties strongly affect light penetration in biological tissues. Tissue optical parameters depend on the laser’s wavelength and control light propagation through tissues. However, optical clearing techniques have been proposed to control tissue scattering via equalizing the refractive index through the tissue components using chemicals of high refractive index. Such a procedure can reduce scattering within tissue and increase its optical transparency. Nowadays, tissue optical clearing can be achieved using different scenarios; physical, chemical, photo-chemical/photothermal, and compression, depending on the physical properties of the studied tissue or organ. The IR lasers are utilized in many medical applications, such as photodynamic therapy and bio-stimulation. Additionally, low-intensity infrared lasers cause small heating, leading to tissue water evaporation and increasing optical transmittance. In the present study, tissue optical transmittance has been evaluated after exposure to different IR laser wavelengths. The collimated transmittance of bovine skeletal muscle samples has been monitored using a 650-nm incident laser. The samples have been irradiated with IR lasers at 785 and 980 nm for different periods (A total of 75 min divided into periods of 15 min). The results show that tissue transmittance increased by 27% and 36.7% after irradiation for 75 min with 785 and 980 nm, respectively. Additionally, the optical microscopic images of the 980-nm irradiated samples show higher resolution than native samples.
Nowadays, optical imaging techniques have been broadly and successfully applied for biological screening and pathogen identification. Spatial Frequency Domain Imaging (SFDI) is a recent non-invasive wide-field optical imaging technique utilized in many medical and clinical procedures such as photodynamic therapy, assessing burn severity, and monitoring wound healing progression. The SFDI technique provides a quantitative mapping of tissue absorption and scattering properties over a wide field of view based on tissue diffuse reflectance/transmittance dependency on the spatial frequency. In a typical SFDI system, broadband light is employed as the illuminating source, whereas in some applications, laser sources could also be used. However, the appearance of laser speckle may influence the captured images and this, in turn, affects the accuracy of the reconstructed optical parameters. Therefore, in the current study, an experimental configuration based on interference has been utilized to reduce the speckle noise contrast of the obtained spatially modulated images. To achieve that, a red laser source with a wavelength of λ = 650 nm is divided into two identical beams using a beam splitter. One beam illuminates a reflecting mirror (reference beam) and the other one illuminates the reflecting window of a spatial light modulator (SLM) (reflected beam). Sinusoidal patterns of different frequencies are displayed on the SLM; hence the reflected beam becomes spatially modulated. The two beams (reference and reflected modulated beams) are combined to pass through a diffuser that simulates a rough tissue and imaged by a CCD camera. The obtained results reveal that the speckle noise contrast has been reduced by an average ratio of 21.89% after applying the interferometric configuration.
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