Patent ID: 11892376
Assignee: STRYKER CORPORATION
Field: Measurement (Instruments)
Classification: CPC G  A | IPC A  G

Claim 8:
9. A patient support comprising:
a mattress having a bladder;
a pneumatic system having a pump for inflating said bladder; and
a leak testing system comprising:
a control system, said control system having one or more memory devices and a sensor, said sensor detecting the pressure in said bladder, and said one or more memory devices comprising a non-transitory computer readable medium comprising stored code, said stored code configured to:
control said pump to pressurize said bladder;
initiate a first test for detecting leakage by directing said pump to pressurize said bladder to a first pressure;
measure, during the first test for detecting leakage, an inflation time to reach the first pressure;
compare the inflation time to a stored acceptable inflation time value, the inflation time corresponding to a first time period and the stored acceptable inflation time value corresponding to a second time period;
after reaching the first pressure of the first test for detecting leakage, initiate a second test for detecting leakage starting from the first pressure of the first test for detecting leakage and including ceasing the pressurization for a third time period greater than zero;
during the second test for detecting leakage, after the third time period, detect a second pressure in said bladder based on one or more signals from said sensor;
during the second test for detecting leakage, at the end of the third time period, measure a fourth time period;
during the second test for detecting leakage, at the end of the fourth time period, sense and measure a third pressure in said bladder, wherein the third pressure represents a reduced pressure from the second pressure;
determine a rate of change from the second pressure to the third pressure in said bladder over the fourth time period;
compare the rate of change to a stored value to determine if there is a leak in the bladder; and
generate a first signal when (1) the inflation time corresponding to the first time period is greater than the stored acceptable inflation time value corresponding to the second time period and a second signal when (2) the rate of change is greater than the stored value indicating a leak in the bladder.