A renal failure therapy system (10) includes: a dialyzer (102)； a blood circuit (100) including a blood pump (120) in fluid communication with the dialyzer (102)； a dialysis circuit (30) in fluid communication with the dialyzer (102)； and at least one flow path insulator (150, 155) located in the dialysis circuit (30) or the blood circuit (100), the flow path insulator (150, 155) including a structure that separates liquid flowing within the flow path insulator (150, 155) into a plurality (e.g., two or more) of separated liquid segments (160) that create electrical isolation within the flow path insulator (150, 155).
