An activation circuit for selectively providing an electrical current to one or more electroactive polymers (EAPs) in a medical device is disclosed. The activation circuit may include a sensor for sensing a measure related to a parameter of an elongated member and/or a balloon of the medical device. The electrical current may be provided to the one or more EAPs according to the sensed parameter of the elongated member and/or the balloon of the medical device. In some cases, the activation circuit may include a comparator for comparing the sensed measure to a threshold to determine when the electrical current is applied to the EAPs. The parameter may be a pressure, a fluid flow, a temperature, and/or other suitable parameter.
