Closed loop infusion pump system with removable glucose sensor

A system for delivering medication to a patient, comprising:

• a sensor unit including implantable glucose sensor means for in vivo monitoring of a patient blood glucose parameter, an implantable connector fitting of generally cylindrical shape for supporting said sensor means within a patient to permit transcutaneous access to said sensor means for removal and replacement through said connector fitting without removing said connector fitting from the patient, and control means coupled by said fitting to said sensor means for generating a signal representative of the monitored patient parameter;
• and
• pump means for administering medication stored therein to the patient, said pump means including means responsive to said signal to administer the medication in accordance with the monitored patient parameter;
• said sensor unit further comprising a catheter having one end connected to said connector fitting and adapted to extend from said fitting generally to a selected in vivo sensing site within the patient, said sensor means comprising a sensor tip and cable means having a distal end thereof connected to said sensor tip and a proximal end for removable mounting within said connector fitting, said cable means and said sensor tip having a size to fit through said connector fitting and said catheter.