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Description
Irreversible electroporation ablation is an irreversible perforation of cell membrane under the pulsed high voltage electric field with certain energy, which leads to cell death and apoptosis, finally achieves the ablation of tumors. The developing technology used by microsecond pulse generator raises a series of new requirements for generator: output voltage pulses with adjustable voltage levels, pulse width and frequency, bipolar pulse, high voltage, fast rising time, high repetition frequency, miniaturization and strong adaptability to complex load. In order to meet the requirement, a bipolar high voltage microsecond pulse generator based on all solid-state Marx generator is put forward in this paper.
This pulse generator consists of four Marx circuit stages and full-bridge solid-state modulator. Two MOSFETs, a capacitor and a diode are concluded in each Marx unit. In addition，the full bridge solid-state modulator is used to realize the polarity alteration of output pulses. A control system based on field programmable gate array (FPGA) with phase-locked loop (PLL) function is used to generate control signals. The FPGA control system produces synchronous trigger pulse which is the control signals of MOSFETs to control the pulse width and frequency. The experimental results prove that this generator can produce bipolar pulse. The output voltage amplitude ranges from -3 to 3 kV, pulse width can be regulated from 1 to 1000μs continually with a step size of 1μs, repetition frequency ranges from 1 to 10 Hz and rising time is about 96 ns. The generator has strong load adaptability, adjustable function with output voltage amplitude, pulse width and repetition frequency, and miniaturization of the pulse device. Also, the effect of ablation with the generator is considerable, so it is competent for further exploration on medical experiments under high-voltage pulsed electric field.
