While biosignal analysis has been a mainstay in many medical applications for a number of decades, notably in cardiology, problems remain in the analysis of high volume data and in comparison among time series. Effective comparisons can determine if the state of a particular patient has changed significantly. These comparisons are useful in both long-term and short-term monitoring. Methods will vary depending on the type of signal and the situation. Intelligent agents permit the activation of the appropriate analysis for the signal and the current situation. Agents are defined in terms of both methodology and function. The agent system is described and illustrated in applications to cardiology and neurology.