Medical diagnostics help us evaluate a range of disorders, such as cancer and infectious diseases. In the United States and other developed countries, doctors have access to advanced equipment and laboratories that provide reliable diagnoses. As a result, when we are sick, we feel confident that we will get the treatment we need. Unfortunately, for many developing countries around the world, these kinds of resources do not exist. The Program for Appropriate Technology in Health (PATH)--an international nonprofit that designs health technologies such as vaccines and diagnostics specifically for developing countries--is one organization working to change this imbalance. As a medical diagnostics scientist at PATH, Bernhard Weigl develops inexpensive, portable, user-friendly diagnostics that provide fast and reliable test results. His tools help communities with minimal health care resources get proper care and treatment.