An improved injection device includes containing a pump and pump control circuitry, a handle with a needle for delivering a therapeutic agent to a patient, a cartridge holding the agent and a tube for delivering the agent from the cartridge to the handle. Preferably the cartridge is disposed in a cartridge...http://www.google.co.uk/patents/US6022337?utm_source=gb-gplus-sharePatent US6022337 - Dental anesthetic and delivery injection unit
