Coulter was awarded US Patent #2,656,508, "Means for Counting Particles Suspended in a Fluid". The Coulter principle is most commonly employed in a Coulter counter, which is an analytical instrument designed for a specific task such as counting cells. However, there are numerous other ways to implement the Coulter principle. Several of these have been attempted, some with commercial success, and some purely for academic research. To date, the most commercially successful application of the Coulter principle is in hematology, where it is used to obtain information about patients' blood cells.