Systems, methods, and apparatuses to overcome pump-induced pressure excursions and control aliasing with reduced volume, absorbent negative-pressure therapy systems

A system for treating a tissue site with negative pressure, the system comprising:

• a dressing;
• a negative-pressure source configured to be fluidly coupled to the dressing;
• and
• a pneumatic accumulator configured to be between the dressing and the negative-pressure source, the pneumatic accumulator comprising:
• a housing comprising a rigid sidewall having a first open end and a second open end;
• a first end cap coupled to the first open end, the first end cap having a first port and a first elastomeric member, the first port fluidly coupled to the negative-pressure source;
• and
• a second end cap coupled to the second open end, the second end cap having a second port and a second elastomeric member, the second port fluidly coupled to the dressing;
• wherein the housing, the first end cap, and the second end cap define a chamber configured to be fluidly coupled to the dressing and the negative-pressure source, the chamber having a volume in a range of about 2 to about 5 cubic centimeters;
• wherein under an application of negative pressure, the first elastomeric member and the second elastomeric member are configured to deform toward one another to reduce the volume of the chamber;
• and
• wherein the first elastomeric member is configured to deflect toward the second elastomeric member a first maximum deflection distance and the second elastomeric member is configured to deflect toward the first elastomeric member a second maximum deflection distance, and wherein a gap exists between the first elastomeric member and the second elastomeric member when the first elastomeric member is at the first maximum deflection distance and the second elastomeric member is at the second maximum deflection distance, such that a fluid is still permitted to flow through the pneumatic accumulator when the first elastomeric member is at the first maximum deflection distance and the second elastomeric member is at the second maximum deflection distance.