Leakage detection method for a pressurised medical appliance

1. A method for detecting leakage in a pressurized medical appliance prior to normal operation, the system including an air compressor and an inflatable bag or bladder coupled to the air compressor through the intermediary of a fill valve allowing air to pass to the bladder and a vent valve for venting the system, the fill valve and the vent valve being selectively operable during said normal operation to deliver cyclical pulses of air to inflate and deflate the bladder, the detection method comprising;

a) opening the fill valve to vent the system to atmospheric pressure,

b) closing the vent valve,

c) pressurizing the system by means of the air compressor to a predetermined threshold value,

d) monitoring the pressure gradient or rise over a period of time to said threshold value, and

e) comparing the pressure gradient over said period of time or at intervals of time within said period of time with a pre-specified pressure gradient indicative of system integrity based upon achieving a system pressure of 10 mmHg within 3 seconds of energization of said air compressor whereby to determine the presence or otherwise of air leakage in the system.

2. A method as claimed in claim 1 , including computer programmable means for performing steps (a) through (e).

3. The method of claim 1 , further comprising:

monitoring and measuring the pressure gradient at various points in the system.

4. The method of claim 1 , further comprising:

activating an alarm should system pressure limits not be achieved.

5. The method of claim 1 , wherein the system is pressurized at a steady state.

6. The method of claim 1 , further comprising performing each recited step in claim 1 prior to normal operation of the pressurized medical appliance.

7. Inflation apparatus for medical use comprising an air compressor and an inflatable bladder coupled to the air compressor, a fill valve for allowing air to pass to the bladder, a vent valve for venting the system, the fill and vent valves being selectively operable to deliver cyclical pulses of pressurized air from the compressor periodically to inflate the bladder during normal operation, and means for selective operation of the fill valve and the vent valve whereby to detect for air leakage prior to said normal operation, comprising:

a) means for opening the fill valve to vent the system to atmospheric pressure,

b) means for closing the vent valve,

c) means for pressurizing the system by means of the air compressor to a predetermined threshold value,

d) means for monitoring the pressure gradient or rise over a period of time to said threshold value, and

e) means for comparing the pressure gradient over said period of time or at intervals of time with a pre-specified pressure gradient indicative of system integrity based upon achieving a system pressure of 10 mmHg within 3 seconds of energization of said compressor whereby to determine the presence or otherwise of air leakage in the system.

8. Inflation apparatus as claimed in claim 7 wherein said means for selective operation of the fill valve and vent valve includes computer programmable means.