A degradation data generator is used with a scaffold for delivery within a patient. The degradation data generator includes a driving circuit electrically coupled to drive an impedance of the scaffold. A detection circuit generates degradation data based on the impedance of the scaffold or other properties such as RF or lightwave transmission, conductance or absorption. The degradation data indicates an amount of biodegradation of the scaffold. A wireless transmitter is coupled to transmit the degradation data to a wireless degradation data receiver, while the scaffold is within the patient.