Mattress bladder arrangement for patient bed

A patient support system comprising

• a patient support apparatus including a seat-deck section and a head-deck section movable relative to the seat-deck section between a first position in which the head-deck section is lowered with a first end thereof adjacent to the seat-deck section and a second position in which the head-deck section is pivoted upwardly and the first end becomes further spaced apart from the seat-deck section so as to increase a gap defined between the seat-deck section and the head-deck section,
• a support surface including a first plurality of therapy bladders having portions situated over the seat-deck section, a second plurality of therapy bladders situated over the head-deck section, and a fill bladder situated between the first plurality of therapy bladders and the second plurality of therapy bladders, the first plurality of therapy bladders and the second plurality of therapy bladders being cyclically inflatable and deflatable to provide a therapy to a patient support by the support surface,
• an air source coupled to the fill bladder, the first plurality of therapy bladders, and the second plurality of therapy bladders, and
• a controller coupled to the air source, the controller configured to inflate the fill bladder in response to movement of the head-deck section from the first position to the second position so that the fill bladder expands to increase coverage of the gap formed between the seat-deck section and the head-deck section.