Patent ID: 9677554
Date: 2017-06-13
CPC Classifications: A61M,F04B,F16K,Y10T

Claim:
1. A pump cassette comprising: a primary membrane pump comprising a pumping chamber having an inlet fluidly connected to a first cassette inlet; a mixing chamber having an inlet fluidly connected to an outlet of the primary membrane pump, and an outlet fluidly connected to a cassette outlet; a first metering pump having an inlet fluidly connected to a second cassette inlet, and an outlet fluidly connected to the inlet of the primary membrane pump; and a second metering pump having an inlet fluidly connected to a third cassette inlet, and an outlet fluidly connected to the inlet of the mixing chamber, wherein a) the pumping chamber of the primary membrane pump is arranged to receive a first fluid via the first cassette inlet, and to receive a second fluid from the second cassette inlet, the second fluid being pumped by the first metering pump; b) the mixing chamber is arranged to receive a third fluid via the third cassette inlet, the third fluid being pumped by the second metering pump; and c) the pumping chamber of the primary membrane pump is configured to accommodate a pre-determined volume of the first fluid via the first cassette inlet and a pre-determined volume of the second fluid via the first metering pump, and the mixing chamber is configured to accommodate a pre-determined volume of the first and second fluids from the primary membrane pump and a pre-determined volume of the third fluid from the second metering pump, resulting in a mixing of said pre-determined volumes of the first, second and third fluids for delivery to the cassette outlet.