Blockage and leak detection in multiple dressing reduced pressure wound therapy systems

1. A negative pressure wound therapy apparatus comprising:

a negative pressure source configured to couple, via a plurality of fluid flow paths, to a plurality of wound dressings and provide negative pressure to the plurality of wound dressings, the plurality of fluid flow paths comprising:

a first fluid flow path configured to fluidically connect a first wound dressing to the negative pressure source, the first wound dressing with a first fluid retention capacity; and

a second fluid flow path configured to fluidically connect a second wound dressing to the negative pressure source, the second wound dressing with a second fluid retention capacity;

at least one pressure sensor configured to measure pressure associated with the plurality of fluid flow paths; and

a controller configured to operate the negative pressure source, the controller further configured to:

receive a plurality of pressure measurements from the at least one pressure sensor;

determine from at least some of the plurality of pressure measurements first and second fluid retention capacities of the first and second wound dressings;

determine a blockage threshold based at least in part on the determined first and second fluid retention capacities;

detect presence of a blockage in at least one of the first or second fluid flow paths based at least in part on comparing at least some of the pressure measurements associated with flow of fluid in at least one of the first or second fluid flow paths to the blockage threshold; and

provide an indication of the blockage in response to determining that the blockage threshold is satisfied.

2. The apparatus of claim 1 , wherein the blockage indicates that at least one of the first or second wound dressings contains an amount of fluid that is greater than a capacity threshold but less than the first or second fluid retention capacity.

3. The apparatus of claim 1 , wherein the controller is further configured to determine the first and second fluid retention capacities of the first and second wound dressings based on a duration of time for achieving a negative pressure setpoint following activation of the negative pressure source.

4. The apparatus of claim 3 , wherein the controller is further configured to deactivate the negative pressure source when the negative pressure setpoint has been achieved.

5. The apparatus of any of claim 3 , wherein the duration of time is inversely proportional to a combined first and second fluid retention capacities of the first and second wound dressing.

6. The apparatus of any of claim 1 , wherein the controller is further configured to detect a combined first and second fluid retention capacities of the first and second wound dressing.

7. The apparatus of claim 1 , wherein the controller is further configured to:

determine a rate of pressure change in the first and second fluid flow paths based on at least some of the pressure measurements; and

determine the first and second fluid retention capacities of the first and second wound dressings based on the rate of pressure change.

8. The apparatus of claim 7 , wherein the rate of pressure change is inversely proportional to dressing capacity.

9. The apparatus of claim 1 , wherein the controller is configured to determine at least one peak-to-trough pressure measurement and detect presence of the blockage based on comparing the at least one peak-to-trough pressure measurement to the blockage threshold.

10. The apparatus of claim 1 , wherein the controller is further configured to:

determine a leak threshold based at least in part on the determined first and second fluid retention capacities;

detect presence of a leak in at least one of the first or second fluid flow paths based at least in part on comparing at least some of the pressure measurements associated with flow of fluid in at least one of the first or second fluid flow paths to the leak threshold; and

provide an indication of the leak in response to determining that the leak threshold is satisfied.

11. A method of operating a negative pressure wound therapy apparatus comprising:

by a controller of the negative pressure wound therapy apparatus, operating a negative pressure source of the negative pressure wound therapy apparatus, wherein the negative pressure source is configured to couple, via a plurality of fluid flow paths, to a plurality of wound dressings, the plurality of fluid flow paths comprising:

a first fluid flow path configured to fluidically connect a first wound dressing to the negative pressure source, the first wound dressing with a first fluid retention capacity; and

a second fluid flow path configured to fluidically connect a second wound dressing to the negative pressure source, the second wound dressing with a second fluid retention capacity; and

by the controller:

receiving a plurality of pressure measurements from at least one pressure sensor of the negative pressure wound therapy apparatus;

determining from at least some of the plurality of pressure measurements first and second fluid retention capacities of the first and second wound dressings;

determining a blockage threshold based at least in part on the determined first and second fluid retention capacities;

detecting presence of a blockage in at least one of the first or second fluid flow paths based at least in part on comparing at least some of the pressure measurements associated with flow of fluid in at least one of the first or second fluid flow paths to the blockage threshold; and

providing an indication of the blockage in response to determining that the blockage threshold is satisfied.

12. The method of claim 11 , wherein the blockage indicates that at least one of the first or second wound dressings contains an amount of fluid that is greater than a capacity threshold but less than the first or second fluid retention capacity.

13. The method of claim 11 , further comprising, by the controller, determining the first and second fluid retention capacities of the first and second wound dressings based on a duration of time for achieving a negative pressure setpoint following activation of the negative pressure source.

14. The method of claim 13 , further comprising, by the controller, deactivating the negative pressure source when the negative pressure setpoint has been achieved.

15. The method of claim 13 , wherein the duration of time is inversely proportional to a combined first and second fluid retention capacities of the first and second wound dressing.

16. The method of claim 11 , further comprising, by the controller, detecting a combined first and second fluid retention capacities of the first and second wound dressing.

17. The method of claim 11 , further comprising, by the controller:

determining a rate of pressure change in the first and second fluid flow paths based on at least some of the pressure measurements; and

determining the first and second fluid retention capacities of the first and second wound dressings based on the rate of pressure change.

18. The method of claim 17 , wherein the rate of pressure change is inversely proportional to dressing capacity.

19. The method of claim 11 , further comprising, by the controller, determining at least one peak-to-trough pressure measurement and detect presence of the blockage based on comparing the at least one peak-to-trough pressure measurement to the blockage threshold.

20. The method of claim 11 , further comprising, by the controller:

determining a leak threshold based at least in part on the determined first and second fluid retention capacities;

detecting presence of a leak in at least one of the first or second fluid flow paths based at least in part on comparing at least some of the pressure measurements associated with flow of fluid in at least one of the first or second fluid flow paths to the leak threshold; and

providing an indication of the leak in response to determining that the leak threshold is satisfied.