Experimental Study Of Laser Ablation Threshold Of Nasopharynx And Larynx Tissue In Vivo

This paper was summarized the investigative status of the application of laser ablation of biotissue in bio-medical domain. At this time, more and more scientists, who are medicals, biologists, physicists, etc, pay attention to the laser technologies in the study of diagnosing and therapy diseases. This thesis is devoted to study relationship between tissue ablation threshold and dose by combining animal experimental means and numerical analysis.At first, a short introduction to the history of the study of laser ablation in bio-tissue was briefly outlined. The physical implication of ablation threshold and situation of application in medical scare were also given.Then, the bases of tissue photo-heat response were discussed. Through overview the transformation of bioheat, the processes of bioheat response were analysis.Thirdly, average ablation diameter in the nasopharynx of rabbit and larynx of rabbit in vivo were experimental measured under the irradiation of Nd:YAP laser. The phenomena of irradiated tissues under eyes, optical microscope and electron microscope was respectively observed. The ablation range of laser ablation was being found.Finally, as a supplementary study, the optical and thermal parameters were obtained by experiential formula. The numerical simulation of optical energy distributions was carried out in the nasopharynx of rabbit and compared with the animal experiments. The absorb parameter for nasopharynx of rabbit was predicted.