title: Method for optodynamic source localization during Er:YAG laser ablation.
abstract: We present an improved optodynamic (OD) method which enables measurement of the distance between the OD source on the ablated surface and a piezoelectric sensor above it, with a relative error of about 1%. The method is based on the point explosion model and allows determination of the distance to the OD source and the released energy for each detected OD signal. We estimate the distance and released energy on the basis of two measured OD signal characteristics: the time of flight and the duration of the compressive phase. We show that the finite aperture of the sensor needs to be taken into account to improve measurement accuracy. We present experimental validation of the method using an Er:YAG laser and water as a tissue phantom. We observe an excellent agreement between the measured and theoretical OD signals and between the measured and estimated distances. The method opens the way to practicable implementations of on-line OD monitoring of laser ablation in surgery and medicine.
authors.affiliation: Fotona d.d., Stegne 7, 1000 Ljubljana, Slovenia.
authors.forename: Georgije
authors.initials: G
authors.lastname: Bosiger
authors.forename: Tadej
authors.initials: T
authors.lastname: Perhavec
authors.forename: Marko
authors.initials: M
authors.lastname: Marinček
authors.forename: Janez
authors.initials: J
authors.lastname: Diaci
mesh_terms: D053685:Laser Therapy / Q000295:instrumentation* / Q000379:methods; D053844:Lasers, Solid-State; D019047:Phantoms, Imaging; D055585:Physical Phenomena; D015203:Reproducibility of Results