A medical instrument includes a housing, an RF generation circuit activation button coupled to an activation button lever supported by the housing. The activation button lever includes a top surface, the activation button lever rotatable about an activation button pivot point. A cutting blade is operably coupled to a sheath. A control lever is supported by the housing and pivotally coupled to a trigger lever including a projection to engage the top surface of the activation button lever and to control the actuation of the cutting blade by actuating the sheath in a distal direction by rotatably moving the control lever proximally about a trigger pivot point. The top surface of the activation button lever and the projection of the trigger lever remain engaged to prevent actuation of the cutting blade until the activation button is fully rotatably moved proximally about the activation button pivot.