Karakterizacija titanove optoakustične leče

magistrsko delo magistrskega študijskega programa II. stopnje Strojništvo

Lovrenc Valič (Author), Matija Jezeršek (Mentor)

Abstract

Optoakustične leče se uporablja za vzbujanje in fokusiranje mehanskega valovanja, kar je uporabno zlasti v biomedicini za diagnostiko in zdravljenje mehkih tkiv. Pri tem se uporablja kratke laserske bliske, ki na površini leče povzročijo kratkotrajno ablacijo in odriv snovi v smeri širjenja valovanja. V magistrskem delu smo raziskali lasersko vzbujene optoakustične pojave z uporabo titanove leče. Ugotovili smo, da se pri dovolj visokih energijah laserskih bliskov pojavijo kavitacijski mehurčki, ki imajo podobno dinamiko tako v vzorcih iz agarja kot tudi v vodi. Oscilacijski časi kavitacijskih mehurčkov pri vzorcih iz agarja so značilno krajši v primerjavi z oscilacijskimi časi kavitacijskih mehurčkov v vodi (20 µs za agar in 250 µs za vodo). Minimalna energija bliska za nastanek kavitacijskih mehurčkov v agarju znaša 350 mJ. Enako kot pri vzorcih vode je rast kavitacijskih mehurčkov linearno povezana z rastjo energije bliska. Ugotovili smo, da se pri nižjih energijah in zaporednih strelih v isto točko količina kavitacijskega oblaka zmanjšuje in da se težišče kavitacijskega oblaka po prvem zaporednem strelu hitro spremeni ter nato ustali.

Keywords

magistrske naloge;optoakustika;laser;optoakustična leča;kavitacijski oblak;tkivni fantom;

Data

Language:	Slovenian
Year of publishing:	2022
Typology:	2.09 - Master's Thesis
Organization:	UL FS - Faculty of Mechanical Engineering
Publisher:	[L. Valič]
UDC:	535+534:532.528(043.2)
COBISS:	100054531
Views:	373
Downloads:	31
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Characterization of titanium optoacoustic lens
Secondary abstract:	Optoacoustic lenses are used for focusing and generation of mechanical waves, which is particularly useful in biomedicine for the diagnosis and treatment of soft tissues. Short laser pulses are used for causing short-term ablation and repulsion of the substance in the direction of wave propagation on the surface of the lens. In the master 's thesis, we investigated laser - excited optoacoustic phenomena using a titanium lens. We found that at sufficiently high laser pulse energies, cavitation bubbles appear, which have similar dynamics in both agar and water samples. The oscillation times of cavitation bubbles in agar are significantly shorter compared to the oscillation times of cavitation bubbles in water (20 μs for agar and 250 μs for water). The minimum laser pulse energy for cavitation bubbles in agar is 350 mJ. As with water samples, the growth of cavitation bubbles is linearly related to the growth of laser pulse energy. We found that at lower energies and successive shots in the same point, the amount of cavitation cloud decreases, and that barycentre of the rectangle cavitation cloud changes rapidly after the first consecutive shot and then stabilizes.
Secondary keywords:	master thesis;optoacoustic;optoacoustic lens;cavitation cloud;tissue phantom;
Type (COBISS):	Master's thesis/paper
Study programme:	0
Embargo end date (OpenAIRE):	1970-01-01
Thesis comment:	Univ. Ljubljana, Fak. za strojništvo
Pages:	XXII, 56 str.
ID:	14624535