Patent ID: 8556867

Claim:
A diabetes management system comprising: a data management unit including: a memory; a processor coupled to the memory; a display coupled to the processor; and a transceiver to receive and transmit data; and a drug delivery system including: a drug delivery pen comprising: a generally tubular pen housing that extends from a first end to a second end, the housing enclosing at least a portion of a plunger rod coupled to a drug cartridge disposed proximate the first end, the pen housing having a dosage indicator window and a dosage selector coupled to the plunger rod; an add-on communication unit comprising: an add-on housing extending along a first longitudinal axis from a first housing end to a second housing end, the add-on housing including an engagement portion that circumscribes at least a portion of the pen housing and capable of being separated from the drug delivery pen, in which the engagement portion comprises first and second extensions, each of the extensions having first and second locating tangs, each locating tang protrudes beyond each of the first and second extensions to fix the add-on housing to the dosage indicator window, and further in which the housing includes: a memory unit; a processor coupled to the memory; an analog-to-digital converter coupled to a dosage sensor attached to the dosage selector of the pen, in which the dosage sensor is disposed in the add-on housing and located on one side of the first longitudinal axis, a power source disposed in the housing, located on another side of the first longitudinal axis and spaced apart from the dosage sensor, the processor being disposed in the add-on housing proximate the first longitudinal axis, and further in which the dosage sensor comprises a longitudinal member slidable along the longitudinal axis, the longitudinal member connected to a follower portion that extends from the add-on housing proximate the second housing end, and the follower portion being coupled to the dosage selector of the drug delivery pen so as to move longitudinally upon rotation of the dosage selector with respect to the pen housing, the converter being coupled to the processor so as to provide data upon displacement of the dosage selector; and a transceiver to transmit and receive data relating to dosage delivery of a drug dosage in the drug cartridge to the data management unit.