Domestic research projects

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Research projects (co)funded by the Slovenian Research Agency.

 

  • Member of University of Ljubljana: UL Faculty of Mechanical Engineering
  • Project code: L2-9254
  • Project title: Spatial and temporal shaping of laser light for minimally invasive ophthalmic procedures
  • Period: 01.07.2018 - 30.06.2021
  • Range on year: 1,34
  • Head: viš. znan. sod. dr. Tomaž Požar
  • Research activity: Engineering sciences and technologies 
  • Research Organisation: Link
  • Researchers: Link
  • Citations for bibliographic records: Link
Abstract:

The applied research project entitled Spatial and Temporal Shaping of Laser Light for Minimally Invasive Ophthalmic Procedures will explore new approaches to using laser light for the treatment of human eyes in order to reduce the adverse effects of such treatments and to improve therapeutic results. They will focus on identifying physical processes that accompany photoionization and photothermal interaction, as well as on the preparation of appropriate laser light for the selected procedure. The first mechanism is used for laser treatment of floaters (laser vitreolysis), posterior capsulotomy and iridotomy, and the second for laser retinal procedures such as: treatment of yellow femoral edema, age degeneration of the yellow spot and retinal detachment. Two main parts of the research are thus (i) the development of new detection methods for ophthalmology; and (ii) the introduction of new technologies and new types of laser sources into ophthalmic laser systems in order to achieve spatial and temporal shaping of laser light.

In order to determine the therapeutic and side effects objectively, we will test new non-invasive photo-acoustic detection methods in which the analysis of the emitted mechanical waves can reveal information about the interaction of the individual laser pulse deep in the eye tissues. It is possible to incorporate them into existing ophthalmic lenses, which the doctor is already using in the treatment, do not interfere with the patient, or they can also be used as a feedback source for the process of successive laser pulse applications. With this the ophthalmic laser system suggests to the doctor an optimal choice of process parameters settings, reports to him if it is likely to be too close to sensitive tissues, if the site of treatment has an elevated temperature and if secondary eye cavitation occurred in places where permanent damage can occur. We will also use advanced optical methods based on nonlinear optical phenomena (a combination of two-photon excitation and superresolved microspectroscopy / microscopy), as they have better contrast than the linear ones. We intend to combine photoacoustic and advanced optical methods into hybrid detection systems, which is a completely new approach to solving modern ophthalmic problems on a global scale. With the original methods based on optoacoustic and non-linear phenomena for monitoring, characterization, optimization and adaptive management of laser medical procedures, we will be able to explore the possibilities for implementing a programmable spatial light modulator (SLM) and new types of laser sources into ophthalmic laser systems. We expect that with more flexible laser systems, which allow the control and design of the temporal and spatial profile of the laser pulse, we will prepare appropriate laser light for therapy, which will result in more effective and less invasive laser procedures. Research is strongly supported by an industrial partner who will also be involved in research. This will ensure the transfer of knowledge and new technologies directly from research institutes (TRL 1-6) to the manufacturer of ophthalmic laser devices (TRL 7-9). In addition to scientific contributions, the final goals of the above-described research are faster, more efficient and safer laser ophthalmologic medical procedures with a clearer and objective contrast between the therapeutic and the undesirable effects of light-tissue interaction, and thereby improving the quality of the patient's life.

The phases of the project and their realization:
  • WP1 Development and adaptation of new optodynamic methods for the monitoring of light-matter interactions - realized
  • WP2 Development of new hybrid detection concepts for the research and control of light-tissue interaction - realized
  • WP3 Modeling of mechanical responses in light-matter interaction - realized
  • WP4 Modular system for the monitoring, control and analysis of the therapeutic and side effects of the laser treatment of eye floaters and retinal conditions - realized
  • WP5 Temporal laser pulse shaping for ophthalmology - realized
  • WP6 Spatial laser pulse shaping for ophthalmology - realized

Bibliographic references resulting directly from the project implementation:

[1] DULAR, Matevž, POŽAR, Tomaž, ZEVNIK, Jure, PETKOVŠEK, Rok. High speed observation of damage created by a collapse of a single cavitation bubble. Wear, Jan. 2019, vol. 418/419, str. 13-23 [COBISS.SI-ID 16342555], Objavljeno: 8. 11. 2018

[2] POŽAR, Tomaž, HORVAT, Darja, STARMAN, Bojan, HALILOVIČ, Miroslav, PETKOVŠEK, Rok. Pressure wave propagation effects in the eye after photoablation. Journal of applied physics, May 2019, vol. 125, iss. 20, str. 1-9 [COBISS.SI-ID 16628763], Objavljeno: 22. 5. 2019

[3] PETKOVŠEK, Rok, AGREŽ, Vid, PETELIN, Jaka, ČERNE, Luka, BÜNTING, Udo, PODOBNIK, Boštjan. Pulses on demand in fibre and hybrid lasers. Strojniški vestnik, Nov./Dec. 2019, vol. 65, no. 11/12, str. 680-689 [COBISS.SI-ID 16944411], Objavljeno: 15. 11. 2019

[4] POŽAR, Tomaž, PETKOVŠEK, Rok. Cavitation induced by shock wave focusing in eye-like experimental configurations. Biomedical optics express, Jan. 2020, vol. 11, no. 1, str. 432-447 [COBISS.SI-ID 16998683], Objavljeno: 23. 12. 2019

[5] AGREŽ, Vid, POŽAR, Tomaž, PETKOVŠEK, Rok. High-speed photography of shock waves with an adaptive illumination. Optics letters, Mar. 2020, vol. 45, iss. 6, str. 1547-1550 [COBISS.SI-ID 17080347], Objavljeno: 18. 2. 2020

[6] PODLIPEC, Rok, MUR, Jaka, PETELIN, Jaka, ŠTRANCAR, Janez, PETKOVŠEK, Rok. Two-photon retinal theranostics by adaptive compact laser source. Applied physics. A, Materials science & processing, 2020, vol. 126, iss. 6, str. 1-9 [COBISS.SI-ID 14993923], Objavljeno: 11. 5. 2020

[7] HORVAT, Darja, POŽAR, Tomaž, STARMAN, Bojan, HALILOVIČ, Miroslav, PETKOVŠEK, Rok. Pressure wave focusing effects following laser medical procedures in human eyes. Applied physics. A, Materials science & processing, Jun. 2020, vol. 126, iss. 6, str. 1-9 [COBISS.SI-ID 15652611], Objavljeno: 8. 9. 2020

[8] POŽAR, Tomaž, AGREŽ, Vid, PETKOVŠEK, Rok. Laser-induced cavitation bubbles and shock waves in water near a concave surface. Ultrasonics Sonochemistry, May 2021, vol. 73, str. 1-11 [COBISS.SI-ID 45742083], Objavljeno: 4. 1. 2021

[9] PODLIPEC, Rok, MUR, Jaka, PETELIN, Jaka, ŠTRANCAR, Janez, PETKOVŠEK, Rok. Method for controlled tissue theranostics using a single tunable laser source. Biomedical optics express. 2021, vol. 12, no. 9, str. 5881-5893 [COBISS.SI-ID 75069699], Objavljeno: 30. 8. 2021

[10] PETELIN, Jaka, LOKAR, Žiga, HORVAT, Darja, PETKOVŠEK, Rok. Localized measurement of a sub-nanosecond shockwave pressure rise time. IEEE transactions on ultrasonics, ferroelectrics, and frequency control. [Print ed.]. Jan. 2022, vol. 69, no. 1, str. 369-376 [COBISS.SI-ID 78110211], Objavljeno: 24. 9. 2021