Plasma gun for medical applications: engineering an equivalent electrical target of human body and deciphering relevant electrical parameters

TL;DR

This paper develops an electrical equivalent model of the human body for calibrating plasma medical devices, analyzing plasma interactions at different voltages to ensure safety and therapeutic effectiveness.

Contribution

It introduces a realistic electrical target mimicking human dielectric properties and evaluates plasma gun operation modes for medical applications.

Findings

The equivalent electrical human body model accurately mimics dielectric properties.

Plasma gun operates in therapeutic pulsed mode between 3.0 and 8.5 kV.

Higher voltages cause thermal arcs, posing risks.

Abstract

Simulations and experimental works have been carried out in a complementary way to engineer a basic material target mimicking the same dielectric properties of the human body. It includes a resistor in parallel with a capacitor, whose values (Rh=1500 {\Omega} and Ch=100 pF) are estimated in regard of parameters commonly utilized upon in vivo campaigns (frequency=30 kHz, gap=10 mm, high voltage electrode surface=12.6 mm2). This equivalent electrical human body (EEHB) circuit can be used as a reference and realistic target to calibrate electrical properties of therapeutic plasma sources before their utilization on patients. In this letter, we consider a configuration where this EEHB target interacts with a plasma gun (PG). Plasma power measurements performed in such configuration clearly indicate two operating modes depending on the value of the supplied voltage. Hence, the plasma gun generates pulsed atmospheric plasma streams likely to present therapeutic interest for voltages comprised between 3.0 and 8.5 kV while for higher values, transient arcs of thermal plasma are generated and represent substantial risks for the patient.