Computer assisted intervention (CAI) systems require the integration of an increasing number of devices,
including medical monitors, sensors, tracking devices and robots. This complexity makes applications
harder to develop, more difficult to debug and the accumulation of ad hoc interfaces reduces the overall
portability. We describe a set of libraries, the cisst libraries, developed at the Johns Hopkins University
to address some of the problems encountered when integrating devices for CAI. We focus on three main
characteristics of the cisst libraries: software architecture, multi-threading and CAI specific interfaces.