an automated therapy system having an infusion catheter ; a sensor adapted to sense a patient parameter ; and a controller communicating with the sensor and programmed to control flow output from the infusion catheter into a patient based on the patient parameter without removing fluid from the patient . the invention also includes a method of controlling infusion of a fluid to a patient . the method includes the following steps : monitoring a patient parameter with a sensor to generate a sensor signal ; providing the sensor signal to a controller ; and adjusting fluid flow to the patient based on the sensor signal without removing fluid from the patient .