Dr. Larry Weed has described the knowledge coupling problem as the explosion of medical knowledge, the limits of human memory and the need for easy access to the right information at the right time. Knowledge coupling is a problem in all fields of medicine, but especially in the information-intensive field of occupational toxicology. Intelligent relational databases developed by physician experts can help us solve this problem. In an intelligent database, the information needed to make decisions is mapped into a relational database. The mapping process involves the comprehensive and systematic selection of information. Knowledge is conveyed by what is included and what is not included in the map.