US Patent 9993595 Patch pump cartridge attachment

A user-wearable patch pump system for delivery of insulin or other medicament can include a patch pump having a reusable drive unit and a replaceable and refillable cartridge. The cartridge can selectively attach to and be detached from the drive unit. The cartridge can initially be inserted onto the drive unit in a first orientation at an angle to the drive unit and then be rotated to align the cartridge with the drive unit and lock the cartridge in place on the drive unit to form the patch pump.