System and method to clear conduits of fluids after instillation to a wound
View Patent ↗A wound therapy system and method for clearing fluids from a conduit includes a wound dressing apparatus, a pneumatic pump, a valve, and a controller. The wound dressing apparatus is fluidly coupled to a wound, the pump, and the valve. The controller is configured to determine a volume of instillation fluid that has been delivered to the wound, to operate the pneumatic pump and the valve to apply a negative pressure to the wound dressing apparatus to purge a first portion of the instillation fluid, and to operate the pneumatic pump and the valve during a purge operation to deliver a volume of air through the wound dressing apparatus that is approximately equal to or greater than the volume of instillation fluid to purge a second portion of the instillation fluid from the wound dressing apparatus.
1. A wound therapy system, comprising:
a wound dressing apparatus fluidly coupled to a wound;
a pneumatic pump fluidly coupled to the wound dressing apparatus and configured to apply a negative pressure to the wound dressing apparatus;
a removable fluid canister coupled to the wound dressing apparatus and the pneumatic pump;
a sensor fluidly coupled to the removable fluid canister and configured to determine a negative pressure of the removable fluid canister;
a valve fluidly coupled between an ambient environment and the wound dressing apparatus at a location that is upstream of the wound, the valve being configured to allow airflow between ambient environment and the wound when the valve is open; and
a controller communicatively coupled to the pneumatic pump, the sensor, and the valve and configured to:
determine a volume of instillation fluid that has been delivered to the wound;
operate the pneumatic pump and the valve to apply the negative pressure to the wound dressing apparatus to purge a first portion of the instillation fluid from the wound dressing apparatus;
initiate a purge operation based on a determination that the negative pressure of the removable fluid canister is above a predefined purge trigger pressure; and
operate the pneumatic pump and the valve during the purge operation to deliver a volume of air from the ambient environment through the wound dressing apparatus that is approximately equal to or greater than the volume of instillation fluid to purge a second portion of the instillation fluid from the wound dressing apparatus.
2. The wound therapy system of claim 1 , wherein the removable fluid canister is configured to receive the instillation fluid from the wound dressing apparatus during the purge operation.
3. The wound therapy system of claim 1 , wherein during the purge operation the controller is configured to operate the pneumatic pump to maintain the negative pressure of the removable fluid canister to a value that is approximately equal to a predefined target therapy pressure at the wound.
4. The wound therapy system of claim 1 , wherein during the purge operation the controller is configured to operate the pneumatic pump to maintain the negative pressure of the removable fluid canister to a value that is greater than a predefined target therapy pressure at the wound by a predefined threshold.
5. The wound therapy system of claim 1 , wherein during the purge operation the controller is configured to hold the valve open for a period of time within a range between approximately 5 and 20 seconds.
6. The wound therapy system of claim 1 , wherein the wound dressing apparatus comprises a wound dressing and a fluid conduit, wherein the fluid conduit comprises at least one sensing lumen and a vacuum lumen, and wherein the volume of air is approximately equal to a total volume of the at least one sensing lumen and the vacuum lumen.
7. The wound therapy system of claim 1 , wherein during the purge operation the controller is configured to repeatedly open and close the valve at a predefined operating frequency.
8. The wound therapy system of claim 1 , wherein the valve is a digitally variable, pulse-width-modulation driven valve, and wherein during the purge operation the controller is configured to continuously vary an operating frequency of the valve to provide a gradual increase in flow rate at a beginning of the purge operation and an end of the purge operation.
9. The wound therapy system of claim 1 , wherein the controller is configured to continuously repeat the purge operation for a predefined number of cycles or for a predefined time period.
10. The wound therapy system of claim 1 , further comprising an instillation fluid canister configured to contain the instillation fluid and an instillation pump configured to deliver the instillation fluid from the instillation fluid canister to the wound dressing apparatus.
11. The wound therapy system of claim 1 , wherein the valve is fluidly coupled to the wound dressing apparatus at a location that is upstream of the wound and the pneumatic pump.