Recent developments in wireless sensors to measure physiological parameters and environmental parameters enable a new generation of applications for health monitoring. However, the complexity of many physiological signals and the need to process sensor data in real-time makes programming such applications a challenging task. This chapter motivates the need to step-wise reduce the complexity of sensor data to enable medical experts to tailor and develop (parts of) applications without having in depth programming skills. To achieve this goal, a methodology for application development with real-time sensor data processing is presented. The methodology is based on the concepts of physical and logical sensors, which can detect atomic and composite events. The combination of using the declarative approach of Complex Event Processing and modularization allows processing most data in the event space instead of signal processing. A use case for a home care application demonstrates the strength of this methodology.