A tissue treatment device includes a circuit driver, an electrode, and a plasma arc focusing element, all disposed within a housing. The circuit driver generates a plasma arc source signal. The electrode generates a plasma stream in response to the plasma arc source signal. The plasma arc focusing element focuses the plasma stream to pass through an outlet hole of the housing and onto a target spot on a target tissue of a treatment subject for heat treatment of the target tissue. In some embodiments, the circuit driver controls a temperature increase of the target tissue by modulating a fundamental frequency, power level, pulsing frequency, and/or pulsing duty cycle of the plasma arc source signal.
