Two Successive Shock Waves Generated by Underwater Pulse Electric Discharge for Medical Applications

Abstract

This paper reports on analysis of two different types successive underwater shock waves generated by a device incorporating a compact shock-wave generator with a magnetic pulsed compression circuit. To generate shock waves, underwater pulsed electric discharges in high-impedance saline water were used. The saline water made possible underwater shock waves propagation in tissue with low reflection between the solution and tissue boundary, owing to their similar acoustic impedances. A cylindrical electrode holder and a semiellipsoidal shock-wave focusing reflector/generator were used in this paper. The diameter of the compact shock-wave reflector was 20 mm. Two kinds of successive underwater shock waves, one generated by electric discharge plasma expansion and the other by bubble collapse, were observed. The shock waves were studied by time-resolve high-speed visualization and direct pressure measurement using a fiber optic probe hydrophone pressure transducer. The former method elucidated propagation of underwater shock waves and behavior and collapse of the bubble near the electrodes, while the later measured two kinds of underwater shock waves pressures at different voltage amplitudes using the cylindrical electrode holder and the shock focusing generator. This paper clearly shows the importance of the secondary shock waves, their control, and damping, for effective and safe medical application of shock waves.

Plasma–Saline Water Interaction: A Systematic Review

“…Of the 37 articles chosen, most of the investigations do not apply to an isolated research field, but as associations between environmental and biological, physical or chemical studies, for example [ 20 , 21 , 22 , 23 , 29 , 38 , 50 , 52 ]. However, considering the main parameters investigated by the authors and the research objectives, a distribution of studies in macro-research fields allows a more detailed visualization of the main sectors in which the treatment is currently used ( Figure 2 ).…”

“… Macro-research fields of the included studies in this review. Fundamental [ 21 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 50 , 52 , 54 , 58 , 59 ], plasma medicine [ 20 , 22 , 31 , 32 , 38 , 39 , 40 , 48 , 49 , 51 , 55 , 56 , 60 ], engineering [ 24 , 25 , 26 , 53 ], and environmental [ 19 , 23 , 27 , 28 , 29 , 30 , 57 ]. …”

“… Types of plasma-treated saline water. PBS [ 22 , 39 , 40 , 44 , 51 , 57 , 60 ]; NaCl 0.9% [ 22 , 47 , 48 , 50 , 51 , 56 , 58 ]; artificial sea water [ 21 , 27 , 28 , 29 , 41 , 42 , 43 , 54 ]; natural sea water [ 19 , 20 , 23 , 24 , 25 , 26 , 38 , 59 ]; other saline solutions [ 30 , 31 , 32 , 45 , 46 , 49 , 52 , 53 , 55 ]. …”

Lightning under water: Diverse reactive environments and evidence of synergistic effects for material treatment and activation

“…122 One more important factor of the shock wave in liquid is the formation of a wide range of high-frequency oscillations at the megahertz levels. 121 Apparently, these oscillations are capable of effectively exciting and activation molecules and complexes in liquid solutions.…”

Signal Analysis and Waveform Reconstruction of Shock Waves Generated by Underwater Electrical Wire Explosions with Piezoelectric Pressure Probes

“…Another good choice for underwater high-pressure measurement is the fiber optic probe hydrophone. This kind of indirect pressure sensor detects the refractive index of water at the fiber-water interface, which varies with the water density [ 10 ]. The main disadvantage of this method is the relatively lower sensitivity (for example 2 mV/MPa for a FOPH 2000 device made by RP Acoustics, Lautenbach, Germany), so it is more suitable for high-pressure measurements.…”