Statistical Analysis of Instantaneous Effect of Polarized He-Ne Laser Radiation on the Elastic Modulus of Soft Biological Tissue

Introduction: This work is dedicated to investigating the effect of applying polarized He-Ne laser beam (λ= 632 nm, 10 mW, 1 j/cm2) with polarization direction perpendicular to the stress direction on the tensile strength of biological tissue (elasticity index of the Pleura 10*4*0.1 mm).   Method and Material: The optimized characteristics of the laser illumination in the minimum times of radiation is detected here through some series of designed experiments and the results are completely applicable to the new investigations. To achieve the purpose, the experiments are designed in full factorial design model to study the effecting factor of viscoelastic modules of the pleura. The employed factor is time duration of the exposure. different irradiation timing is 5 s, 10 s, 15 s and 20 s.   Result: Through the variance analysis it is found that time duration of radiation plays very important role on its viscoelastic characteristics. Additionally, it is revealed that a special condition, the time of exposure =10 sec, leads to the highest value of relative elastic modulus, i.e., the most increase in the tensile strength of the Pleura because of dehydration of cells is happened in longer time irradiation than 10s and no effect in less duration than 10s.   Conclusion: This conclusion can be useful in dealing with wound scars, reforming the shape of the cornea, cartilage reshaping and et.