A breakthrough study by Taiwan National Chung-Hsing University, Departmental of Civil and Environmental Engineering, has proven that the health of a structure can be accurately diagnosed by using only 3 seismic units. Analysing data from a large number of units over a number of earthquakes, the university was able to prove the ability of this new methodology to accurately show the health of a building. The system calculates the rigidity and actual displacement to provide rapid structural health diagnostics (RSHD). This greatly reduces the cost to determine building safety and also helps engineers to rapidly assess the health of the structure enabling companies to return to work as soon as possible in undamaged buidlings.