US Patent 10052441 System and method for measuring delivered dose

A flow sensor is provided to enable volumetric dose data to be acquired automatically by sampling flow rates of insulin measured by a flow sensor exposed to a flow manifold though which the insulin flows. The flow sensor preferably connects to a standard insulin pen on one end, and to a standard pen needle on the other end. Particular geometries and algorithms are utilized to accommodate the unique requirements of insulin flow determination during an injection event.