20.500.12556/RUL-114102 GENERIRANJE VISOKONAPETOSTNIH PULZOV ZA NA ELEKTROPORACIJI TEMELJEČE TEHNOLOGIJE IN TERAPIJE HIGH VOLTAGE PULSE GENERATION FOR ELECTROPORATION BASED TECHNOLOGIES AND THERAPIES Elektroporacija je vsestranska tehnologija, ki je že uveljavljena na številnih področjih. Merjenje napetosti in toka dovedenih elektroporacijskih pulzov je ključno za doseganje učinkovite elektroporacije, saj le tako lahko zagotovimo kakovost aplikacije. Najbolj zahtevno je natančno merjenje visokonapetostnih kratkih nanosekundnih pulzov. Poudariti je potrebno, da se pasovna širina sond konča pri -3 dB, kar pomeni, da ima sonda na koncu pasovne širine napako -29 %. Napaka -29 %, je sprejemljiva za elektroniko, vendar pa ima lahko amplituda, ki odstopa za 29 % drugačen biološki učinek. Ker sta permeabilizacija in preživetje celic sigmoidni funkciji napetosti, lahko ima že več kot 10 % razlika v napetosti bistveno drugačen biološki učinek. Pri uporabi merilnih sond se moramo vedno zavedati napake. Pri komercialno dostopnih sondah je merilna napaka navedena v podatkovnem listu, vendar je včasih kljub temu spregledana, prototipne sonde pa je pred uporabo potrebno pravilno umeriti in ovrednotiti merilno napako. Elektroporacijska naprava, razvita v okviru te doktorske disertacije, deluje v skladu s pričakovanji, maksimalna izhodna napetost je 4 kV, teoretični maksimalni tok 131 A, minimalna dolžina pulza 200 ns in maksimalna ponavljalna frekvenca 2 MHz. Naprava generira asimetrične bipolarne pulze, kar pomeni, da lahko uporabnik hkrati nastavi asimetrijo trajanja pulzov in napetostno amplitudno asimetrijo. Tako omogoča raziskovanje še neznanih učinkov, nadaljno raziskovanje oziroma nadgradnjo raziskav učinka občutljivosti in preklica ter in vivo raziskave visokofrekvenčne elektroporacije. Naprava je bila testirana in vivo pri prvi visokofrekvenčni elektrokemoterapiji na miših. Spremljali smo učinkovitost terapije in krčenje mišic med dovajanjem električnih pulzov. Rezultati kažejo, da je učinkovitost HF-ECT z bleomicinom in cisplatinom primerljiva s \klasično" ECT z bleomicinom in cisplatinom. V nasprotju z do sedaj objavljenimi študijami krčenje mišic ostaja signikantno tudi v primeru visokofrekvenčne elektroporacije, vendar smo bili prvi, ki smo električne pulze dovajali prek kože s ploščatimi elektrodami. The first observations of the effects of pulsed electric fields on biological material date more than 250 years back. But in the past two decades applications of electroporation emerged in medicine, food processing, and biotechnology. The phenomenon of electroporation leads to increased cell membrane permeability. Due to exposure to high voltage electric pulses, the cell membrane becomes permeable to molecules, which otherwise can not cross the membrane. A pulsed power generator termed as electroporator and electrodes are used to expose cells to a pulsed electric field. Electroporator generates electrical pulses with a specific shape, amplitude, duration, number, repetition rate and sequence (bursts of pulses). By applying electrical pulses to the electrodes, which are in direct contact with the tissue, an electric field is generated in tissue with specific distribution and intensity. In order to properly understand the current situation and trends of development on the electroporation field, a thesis begins with a review of commercially available devices, their characteristics, limitations, and weaknesses. Also, expert opinion about the electroporation devices used in skin electroporation was provided. The electroporation device manufacturers are currently hindering the development of electroporation field by concealing the output pulse parameters of their devices, designing them in a way to disable output pulse measuring, specifying characteristics which device cannot deliver, and making devices that do not warn the user when pulse delivery fault occurs. The quality of the pulse delivery was evaluated, by checking if the delivered pulses were adequately addressed and measured in the electroporation studies, with the focus on the field of nanosecond electroporation, where the delivery and measuring are the most challenging. Additionally, recommendations for standardization, mainly focusing on the evaluation of electroporators proper or improper operation were proposed and electronic emulator of the biological load during electroporation, which enables constant and sustainable testing and unbiased comparison of different electroporators operation, was developed. Secondly, we developed a high-frequency high voltage generator by using and improving the latest pulse generator designs. The developed 4 kV pulse generator, generates high voltage pulses with minimized switching time between positive and negative pulse. The minimal pulse duration is 200 ns and maximal repetition rate 2 MHz, it is also able to generate asymmetrical bipolar pulses. The developed device was tested in first in vivo high-frequency electrochemotherapy (HF-ECT), in which HF-ECT with bleomycin and cisplatin was proved to be as effective as well established "classical" ECT with bleomycin and cisplatin. Third, the cost-effectiveness of electrochemotherapy of stage IV and IIIc skin melanoma was calculated for patients treated at the Institute of Oncology in Ljubljana using the Cliniporator device and associated electrodes. The probability of ECT (with hospitalization) being cost-effective for the patient with stage IV and IIIc skin melanoma is just above 50 %, which implies the prices of the device and electrodes should be reduced for successful implementation into clinical practice. However, if patients have bleeding lesions the ECT can be assumed cost-effective (probability rises to 0.97). elektroporacija standardizacija razvoj elektroporatorjev analiza stroškovne učinkovitosti electroporation standardization electroporator design cost-effectoveness analysis. true false false Slovenski jezik Angleški jezik Doktorsko delo/naloga 2020-02-14 16:00:02 2020-02-14 16:00:12 2022-08-26 03:49:07 0000-00-00 00:00:00 2020 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 1970-01-01 50161 Pirc_Eva_-_GENERIRANJE_VISOKONAPETOSTNIH_PULZOV_ZA_NA_ELEKTROPORACIJI_TEMELJECE_TEHNOLOGIJE_IN_T.pdf Pirc_Eva_-_GENERIRANJE_VISOKONAPETOSTNIH_PULZOV_ZA_NA_ELEKTROPORACIJI_TEMELJECE_TEHNOLOGIJE_IN_T.pdf 1 08D1865A8175110B12FB804223C47E18 01854f7304fff05167d0ea7ecc9be24521f475f0de60ad4e0f0670a8254affe5 2e98e7a8-a1b8-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=126236 Fakulteta za elektrotehniko 0 0 0