Patent ID: 6500151
Filing Date: 2002-12-31
Classification: A61M

Abstract:
A syringe pump comprising:a mechanism for engaging and driving a plunger of a syringe; and a sensor mechanism for sensing a size of a barrel of the syringe, said sensor mechanism comprising: a contact member displaceable into contact with said barrel, a mask member, having at least a first side, coupled with said contact member and movable in response to movement of said contact member, and a row of a plurality of optical sensors positioned to receive radiation transmitted by the mask member, wherein the mask member includes a plurality of transmitting regions arranged in a row, each transmitting region having a different length, and wherein the pump includes a control unit responsive to at least one output from said sensors, said control unit determining the size of the barrel from a combination of a length of the row of sensors receiving radiation transmitted by one of the transmitting regions and a position of an edge of the transmitting region.