Wireless sensor networks are application-specific networks, and usually a new network design is required for a new application. In event-driven wireless sensor network applications, the sink node of the network is generally concerned with the higher level information describing the events happening in the network, not the raw sensor data of individual sensor nodes. As the communication is a costly operation in wireless sensor networks, it is important to process the raw data triggering the events inside the network instead of bringing the raw data to the sink and processing it there. This helps reducing the total amount of packets transmitted and total energy consumed in the network. In this paper, we propose a new method that distributes the information processing into the sensor network for event-driven applications. We also describe an application scenario, healthcare monitoring application, that can benefit from our approach.