Image Number 15 for United States Patent #5199949.
A multiple pharmaceutical syringe (160), especially useful for use in dispensing insulin, includes a body (162) housing first and second pharmaceutical-filled cartridges (182, 184). The cartridges are of the type with a septum (190) at one end and a piston (224, 225) at the other end with the liquid pharmaceutical (226, 228) between the two. The body also defines an accumulator chamber (202) within which an accumulator piston (238) is slidably mounted. When the cartridges are mounted within the body, the septums are pierced by hollow spikes (188) which are connected to a flow path opening into the accumulator chamber. Check valves (230) are used at the distal ends of the spikes to prevent liquid flow back into the cartridges. Pressing on the cartridge pistons forces the liquids into the accumulator chamber. Once the desired amounts of both liquids are in the accumulator chamber, the needle assembly is mounted to the replaceable fluid path assembly which fluidly couples the needle to the accumulator chamber. The injection is given by driving the accumulators piston using the accumulator stem.