as best seen in fig1 , lens delivery system 10 of the present invention generally includes cartridge 12 and handpiece 14 . as best seen in fig1 cartridge 12 generally has tubular body 16 and injection nozzle 18 . cartridge 12 is molded as a single piece from any suitable thermoplastic , such as polypropylene , and the thermoplastic may contain a lubricity enhancing agent such as those disclosed in u . s . pat . no . 5 , 716 , 364 , the entire contents of which are incorporated herein by reference . alternatively , cartridge 12 may be made from stainless steel or titanium . nozzle 18 preferably is round , oval or elliptical in cross - section and has a cross - sectional area of between around 2 . 2 mm 2 to around 2 . 6 mm 2 . body 16 preferably contains grips 13 that allow easier manipulation of cartridge 12 and provide a mechanism to lock cartridge 12 within notches 15 in handpiece 14 . body 16 also contains lockout tabs 20 that interact with lockout slots 22 in handpiece 14 in the manner described below . handpiece 14 may be of any suitable construction , such as molded thermoplastic or machined aluminum , stainless steel or titanium . handpiece 14 is generally tubular and contains recess 24 near distal end 26 sized and shaped to receive cartridge 12 , as shown in fig3 . recess 24 has generally flat sides 28 to align the longitudinal access of cartridge 12 with the longitudinal axis of handpiece 14 in a generally coaxial fashion , however ; lockout tabs 22 prevent cartridge 12 from fitting within recess 24 in the absence of lockout slots 22 . lockout slots 22 are slightly longer than lockout tabs 20 to allow grips 13 on cartridge 12 to be slid within notches 15 on handpiece 14 . one skilled in the art will recognize that lockout tabs 20 and lockout slots 22 can vary in shape and size so as to allow or prevent any cartridge 12 / handpiece 14 combination . while certain embodiments of the present invention have been described above , these descriptions are given for purposes of illustration and explanation . variations , changes , modifications and departures from the systems and methods disclosed above may be adopted without departure from the scope or spirit of the present invention .
a lens delivery system having a cartridge and a handpiece with a lockout feature . the lockout feature helps to ensure that the appropriate combination of cartridge and handpiece is used .