Razvoj in preizkus visokofrekvenčnega bipolarnega elektroporatorja

MEKUČ, PRIMOŽ (author), Reberšek, Matej (mentor)

V Laboratoriju za biokibernetiko na Fakulteti za elektrotehniko Univerze v Ljubljani raziskujemo elektroporacijo bioloških celic in njeno uporabo v biomedicini in biotehnologiji. Novejše raziskave kažejo, da imajo visokofrekvenčni bipolarni pulzi manjši vzbujalni učinek in večji učinek preklica pulzov, kot nizkofrekvenčni monopolarni pulzi. Predhodni pulzi visokih ponavljalnih frekvenc zmanjšajo občutljivost celic na elektroporacijo za naslednje pulze v vlaku. Prav tako se električno polje bipolarnih pulzov visokih ponavljalnih frekvenc v tkivu porazdeli bolj homogeno. Za sistematično raziskovanje teh učinkov smo zasnovali napravo za generiranje pulzov - visokofrekvenčni bipolarni elektroporator. Naprava omogoča nastavljanje sedmih parametrov električnih pulzov preko uporabniškega vmesnika na tabličnem računalniku. Preko brezžičnega omrežja si tablični računalnik izmenjuje podatke s krmilnikom. Kontrolni sistem se izvaja v procesorjih in vezju FPGA v krmilniku. Za ojačanje pulzov skrbita visokonapetostni napajalnik in H-mostični digitalni ojačevalnik z radiofrekvenčnimi tranzistorji MOSFET. Ločilno merilno vezje zagotavlja varnost uporabnika in naprave z digitalizacijo signalov in optičnimi sklopniki. Najnižja dolžina pulza znaša 400 ns, amplitudo pulza pa lahko nastavljamo med 60 V in 1 kV. Po končanem razvoju smo napravo preizkusili z obremenilnim testom in jo amplitudno ter časovno kalibrirali. Nato smo izmerili tokove in napetosti pulzov pri odprtih sponkah, nizkoprevodnem mediju in visokoprevodnem mediju ter rezultate analizirali. Elektroporator smo preizkusili do te mere, da ga raziskovalci samostojno uporabljajo v celičnih laboratorijih. Naprava je trenutno edinstvena v zmogljivosti, saj v literaturi in pri proizvajalcih nismo našli podatkov o napravi, ki bi omogočala generiranje tako kratkih bipolarnih pulzov s tako visoko ponavljalno frekvenco. Omogoča še nastavljanje nadpovprečnega števila parametrov pulzov v zelo širokem območju. O poskusih z napravo smo že objavili prvi prispevek na mednarodni bioelektrokemijski konferenci.

• Language: Slovenian
• Keywords: elektroporacija, elektroporator, učinek občutljivosti, učinek preklica, vzbujalni učinek, visokofrekvenčni pulzi, bipolarni pulzi, uporabniški vmesnik, kontrolni sistem, LabVIEW, FPGA, myRIO
• Work type: Master's thesis/paper
• Organization: FE - Faculty of Electrical Engineering
• Year: 2017
• PID: 20.500.12556/RUL-96241
• Publication date in RUL: 27.09.2017

Secondary language

• Language: English
• Title: Development and testing of high-frequency bipolar electroporator

Abstract

In the Laboratory of Biocybernetics at the Faculty of Electrical Engineering, University of Ljubljana, we investigate the electroporation of biological cells and its use in biomedicine and biotechnology. Recent studies have shown that high-frequency bipolar pulses have a lower excitation effect and greater pulse cancellation effect than low-frequency monopolar pulses. High-frequency pulses, however, reduce the sensitivity of the cells to electroporation for the next pulses in the pulse train. Moreover, the electric field of high-frequency bipolar pulses is distributed in the tissues more homogeneously. In order to systematically analyse these effects we designed a device for generating pulses - high-frequency bipolar electroporator. The device allows adjusting seven parameters of the electrical pulses via the user interface on the tablet computer. Tablet computer and controller are transferring data through wireless network. The control system is implemented in processors and FPGA circuit in the controller. For pulse generation, the high-voltage power supply and the H-bridge digital amplifier with MOSFETs are used. The minimum length of generated pulses is 400 ns and amplitude can be set between 60 V and 1 kV. After completing the development of the device we tested it with a load test and did amplitude and time calibration. Then we measured current and voltage signals of the pulses for the open terminals, the low-conductivity medium and the high-conductivity medium. Results were analysed afterwards. We tested electroporator to the extent that now researchers independently use it in cell laboratories. The device is currently unique in performance, as in the literature and at manufacturers we did not find data on the device, which would allow the generation of such short bipolar pulses with such high repetition frequency. It also allows setting an above-average number of pulse parameters in a very wide range. About the experiments with the device, we have already published the first contribution to the international bioelectrochemical conference.

• Keywords: electroporation, electroporator, sensitization effect, cancellation effect, excitation effect, high-frequency pulses, bipolar pulses, user interface, control system, LabVIEW, FPGA, myRIO