Compact High-Voltage AC Generator with Pulse Transformer for High-Frequency Irreversible Electroporation (H-FIRE)

Abstract

This paper is focused on a design of a high-voltage (HV) generator, which is proposed for a high-frequency irreversible electroporation (H-FIRE). The generator produces bursts of bipolar symmetrical pulses. Most HV sources used for cell electroporation are based on a controlled discharge of a capacitor into a resistive load. This solution is very simple, but it is associated with a certain risk of an uncontrolled discharge of the capacitor. We present a different type of the generator, where a DC-AC inverter with pulse transformer is used and where the mentioned risk is eliminated. Our generator is able to deliver bursts with variable length from 50 to 150 μs and a gap between bursts can be set from 0.5 to 1.5 s. Pulse frequency can be varied from 65 to 470 kHz and the output voltage is controlled in two ranges from 0 to 1.3 kV or from 0 to 2.5 kV. Results are presented with resistive load and with tissue impedance load.

The Development of an Electric-Driven Control System for a High-Speed Precision Planter Based on the Double Closed-Loop Fuzzy PID Algorithm

“…By implanting the double closed-loop fuzzy PID and ordinary PID control algorithms in the system, the response time of the two algorithms in the variable speed of the motor is compared to verify the superiority of the algorithm. As shown in Figure 9, Simulink was used to simulate the PWM waveform as the motor input source, change the motor speed by changing the duty cycle of the PWM wave, and use the interactive tablet to receive the motor speed value, which is used to simulate the acceleration and deceleration conditions of agricultural machinery in the field [31]. In the experiment, the driven speed was increased from 50 r•min −1 to 200 r•min −1 and 200 r•min −1 was reduced to 50 r•min −1 to simulate variable speed seeding when the operation was about to end.…”

AC Cell Electroporation Based on Asymmetrical Waveform

“…In the case of AC electroporation, pulses in individual burst can have different duty cycle. For example BUT AC generator [4] produces bipolar pulses with permanent duty cycle 0.5 (B). In publication [5], authors applied pulses with lower duty cycle (C).…”

“…Negative pulse must then have the length of 3 4 𝑇 and amplitude 𝐼 B = 2 3 𝐼 A so that the negative charge 𝑄 B is the same as the positive charge 𝑄 B . If symmetrical pulses (A) transfer energy 𝑊 during one period 𝑇 , then asymmetrical pulses (B) transfer energy 4 3 𝑊 during the same time. In order to be able to compare electroporation effect of both waveforms, it is necessary that the same energy or the same charge is transferred during one period 𝑇 .…”

“…Because the load resistance is changed during the electroporation process and depends on many factors, such as area of electrodes, tissue conductivity, etc, inductors are variable. can also be totally shortcircuited [4]. Both voltage regulators in DC buses must be controlled by control unit with microprocessor.…”