Laser-induced subsurface microdestruction of tissue emerged from the need for a curative targeted destruction of limited regions of tissue within a volume of less than a cubic millimeter that are situated relatively deep under its surface where damage to the surrounding tissue is highly undesirable. Existing methods are mostly based on the mechanical excitation of focussed ultrasonic waves, but such systems are large and cumbersome, and the affected volume is significantly larger than desired. The combination of fast laser and optoacoustic lens offers the possibility of developing a new method of localized tissue destruction using appropriate transient pressure waves that will significantly reduce the size of the affected volume and the contact surface. Laser-induced pressure wave front will be shaped and directed so that its otherwise moderate and harmless amplitudes are combined in a limited region of the tissue where they culminate with a desired destructive effect. Special shape of such a wave front requires highly adaptable methods of generation so that its energy, spatial distribution and time profile can be precisely and accurately controlled which can only be delivered by the opto-mechanical combination of a fast laser and an optoacoustic lens.
To fulfill this demand, we are going to experimentally develop a novel method for spatially and temporally controlled generation of regions of enhanced laser-induced mechanical waves deep beneath the surfaces of tissues and their substitutes. We are going to exhaustively test, analyze and improve the experimental method to reach the optimal performance for the given task. In order to better understand and explain the observed behavior of laser-induced mechanical waves in tissue, we are going to derive a theoretical physico-mathematical model which is going to employ the known physical mechanisms in action during our experiments. We are also going to use the model to simulate and predict the mechanical wave formation with different parameters and under different circumstances that we are going to create during the experimental phase of our research. Then we are going to develop an innovative demonstrational prototype system for laser induction of subsurface enhanced mechanical waves which is going to use specially designed optoacoustic lens to transform a special space- and time-controlled laser pulse into a desired locally enhanced mechanical wave for targeted destruction of tissue within a volume of less than a cubic millimeter inside the treated material.
The research project is going to be executed as a cooperation between the research groups of the Laboratory for Laser Techniques (LASTEH) of The Chair of Optodynamics and Laser Applications at the Faculty of Mechanical Engineering of the University of Ljubljana and of the industrial company Fotona d. o. o. that is specialized in the development and production of medical optoelectronic devices, instruments and accessories. The project research group, headed by assoc. prof. dr. Matija Jezeršek (LASTEH), is made up of several researchers who are key experts in the field of theoretical and experimental light-matter interactions, laser material processing, and development of laser prototype systems that have all the necessary competence, skill, and general know-how to complete the set objectives with numerous references in the applicative research and development of the laser-induced mechanical wave propagation.
The realization of the research project is going to enable further interdisciplinary research of the medical applications of the laser-induced subsurface enhanced mechanical waves in soft tissues. The partnering company is going to have an opportunity to adopt, further develop, and commercialize the newly developed method and the demonstrational prototype system for the clinical use in medicine.
