A closed-loop control for a medical therapeutic system is disclosed that includes one or more processes or components for/in the medical therapeutic system, a controller configured to determine whether one or more operations of the process(es) or component(s) are within a corresponding safety envelope, and one or more sensors. The process(es)/component(s) are configured to deliver a controlled amount of a substance, energy or force to a patient. The sensor(s) are configured to measure or determine a value of a measurable parameter of the process(es)/component(s) and/or effected by the operation(s), and provide the value(s) of the measurable parameter(s) to the controller. The controller determines whether each of the operation(s) are within the corresponding safety envelope according to a corresponding function that mathematically describes the operation. The safety envelope corresponds to known safe values of the measurable parameter, or an unmeasured parameter based on the measurable parameter.