Patent ID: 11946466
Assignee: BAXTER HEALTHCARE SA
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F  A | IPC A  F

Claim 7:
8. A medical fluid delivery machine comprising:
a medical fluid pump including a pneumatically actuated pump chamber and first and second pneumatically actuated medical fluid valve chambers located respectively upstream and downstream of the pneumatically actuated pump chamber;
a compressor for creating positive pressure air; and
an accumulator storing the positive pressure air for delivery to a destination having an operating pressure set by a pneumatic regulator external to the accumulator, the destination including at least one of the pneumatically actuated pump chamber, the first pneumatically actuated medical fluid valve chamber, or the second pneumatically actuated medical fluid valve chamber, the accumulator holding an elastic bladder constructed with a wall thickness that is selected based on the externally set operating pressure and an output pressure of the compressor, wherein the elastic bladder inflates from a resting shape at a bladder inflation pressure, which is a positive pressure greater than the externally set operating pressure and less than the output pressure of the compressor, thereby creating additional positive pressure such that when the pressure in the bladder falls to the bladder inflation pressure from an initial pressure greater than the bladder inflation pressure, the bladder supplies the bladder inflation pressure until the bladder reaches its resting shape, wherein the accumulator includes an outer rigid housing holding the elastic bladder, wherein the bladder is held in a sealed relationship with the outer rigid housing, and wherein the outer rigid housing includes a vent port that is configured to enable air to escape the outer rigid housing as the bladder inflates.