Kajian teoritis hamburan gelombang elektromagnetik dalam tomografi fotoakustik untuk aplikasi biomedis

PURWANTO, Joko, Dr. Mitrayana, M.Si

2009 | Tesis | S2 Ilmu Fisika

Telah dilakukan kajian teoritis sifat-sifat optik jaringan biologis dan hamburan gelombang elektromagnetik oleh jaringan biologis dalam tomografi fotoakustik untuk aplikasi biomedis. Dijabarkan tiga sifat optik jaringan akibat perambatan cahaya dalam jaringan: pembiasan, hamburan dan serapan. Sifat-sifat optik ini dicirikan oleh; indek bias n(lambda) , tampang lintang hamburan h(simbol) , tampang lintang diferensial hamburan h d d  (rumus) , dan tampang lintang serapan s (simbol) . Telaah berbagai tipe hamburan gelombang elektromagnetik dalam jaringan biologis ditinjau berdasarkan ukuran objek penghambur dalam jaringan relatif terhadap panjang gelombang berkas radiasi yang mengenai jaringan. Model geometris hamburan gelombang elektromagnetik dalam jaringan disajikan dalam bentuk matrik Muller dan vektor Jone untuk berkas radiasi terpolarisasi. Berikutnya, dipaparkan mekanisme pembangkitan gelombang akustik dalam jaringan biologis melalui mekanisme ekspansi termoelastik.

A theoretical study of optical properties of biological tissue and electromagnetic wave scattering by biological tissue in tomography photoacoustic for biomedicine aplication had been done. It has been studied three optical properties of biological tissue: refraction, scattering, and absorption. These properties quantified by parameters index of refraction n(lambda) , scattering cross section h(symbol) , differential scattering cross section h d d  (formula) , and absorption cross section s (symbol) . The studied of several electromagnetic wave scattering in tissue is according to the sizes of the scattering object relative to the wave length of light. Geometrical model of polarized light propagation in scattering media was studied used Mueller matrix and vector Jone. Subsecquently, mechanism of photoacoustic generation in tissue via thermoelastic expansion is presented.

Kata Kunci : Optical properties, biological tissue, electromagnetic scattering, Muller matrix, vector Jone.