Electrical safety methods, devices, and systems for medical treatment devices

A method for protecting a patient from an electrical source of a treatment device, the method comprising:

• connecting the patient to a treatment device by a fluid circuit in which a leakage current is induced by capacitive and/or inductive coupling of the fluid circuit with the treatment device over multiple paths to the patient;
• providing conductive elements adjacent the fluid circuit for each of the multiple paths such that they are capacitively coupled to the fluid circuit, wherein the conductive element is electrically isolated from a fluid carried by said fluid circuit and the fluid carried by the fluid circuit is conductive;
• detecting an inducing of a voltage in said conductive elements and detecting a magnitude of the sum of the currents in said multiple paths indicated by voltages in said capacitive and/or inductive coupling;
• and
• in response to the sum
• interrupting a normal operation of the treatment device effective to reduce said leakage current,
• outputting a human perceptible output indicating the magnitude of the voltage, or
• interrupting continuity of said fluid between the treatment device and a patient connector.