Wound therapy system with wound volume estimation
A wound therapy system includes a negative pressure circuit, a pump, a pressure sensor, and a controller. The negative pressure circuit applies negative pressure to a wound. The pump is fluidly coupled to the negative pressure circuit and produces a negative pressure at the wound or within the negative pressure circuit. The pressure sensor measures the negative pressure within the negative pressure circuit or the wound. The controller performs a testing procedure including a first drawdown period, a leak rate determination period, a vent period, and a second drawdown period. The controller is configured to receive one or more pressure measurements of the pressure sensor over the leak rate determination period to determine a leak rate parameter, monitor an amount of elapsed time over the second drawdown period to determine a drawdown parameter, and estimate a volume of the wound based on the leak rate parameter and the drawdown parameter.
1. A wound therapy device comprising:
a pump fluidly coupled to a negative pressure circuit and configured to produce a negative pressure at a wound or within the negative pressure circuit, wherein the negative pressure circuit is configured to apply negative pressure to the wound;
a pressure sensor configured to measure the negative pressure within a negative pressure circuit or at the wound; and
a controller configured to:
operate the pump to produce a negative pressure within the negative pressure circuit;
receive one or more pressure measurements of the pressure sensor over a predetermined time period;
determine a leakage rate based on the one or more received pressure measurements of the pressure sensor over the predetermined time period;
vent the negative pressure circuit to atmospheric pressure;
operate the pump to decrease the negative pressure within the negative pressure circuit at a predetermined rate;
monitor an amount of elapsed time that the pump operates at the predetermined rate until a predetermined pressure is achieved within the negative pressure circuit; and
estimate a volume of the wound based on the leakage rate and the amount of elapsed time.
2. The wound therapy device of claim 1 , wherein the wound therapy device further comprises a vent configured to close while the pump produces a negative pressure within the negative pressure circuit.
3. The wound therapy device of claim 2 , wherein the vent remains closed while the controller determines the leakage rate based on the one or more received pressure measurements of the pressure sensor over the predetermined time period.
4. The wound therapy device of claim 2 , wherein the controller is configured to open the vent to vent the negative pressure circuit to atmospheric pressure.
5. The wound therapy device of claim 2 , wherein the vent is configured to close while the pump is decreasing the negative pressure within the negative pressure circuit at a predetermined rate.
6. The wound therapy device of claim 1 , wherein the controller is configured to operate the pump to produce the negative pressure within the negative pressure circuit at a maximum drawdown rate.
7. A wound therapy system having a negative pressure circuit configured to apply negative pressure to a wound and a pressure sensor configured to measure a pressure within the negative pressure circuit, the wound therapy system comprising:
a controller configured to:
perform a testing procedure comprising a first drawdown period, a leak rate determination period, a vent period, and a second drawdown period;
receive one or more pressure measurements of the pressure sensor over the leak rate determination period to determine a leak rate parameter;
monitor an amount of elapsed time over the second drawdown period to determine a drawdown parameter; and
estimate a volume of the wound based on the leak rate parameter and the drawdown parameter.
8. The wound therapy system of claim 7 , further comprising a pump configured to be fluidly coupled to the negative pressure circuit and configured to produce a negative pressure at the wound or within the negative pressure circuit.
9. The wound therapy system of claim 8 , wherein the first drawdown period comprises operating the pump to achieve a predetermined negative pressure within the negative pressure circuit.
10. The wound therapy system of claim 9 , wherein the leak rate determination period comprises maintaining the predetermined negative pressure for a predetermined time duration and receiving pressure measurements from the pressure sensor during the predetermined time duration.
11. The wound therapy system of claim 8 , wherein the second drawdown period comprises operating the pump to produce a negative pressure within the negative pressure circuit at a predetermined rate.
12. The wound therapy system of claim 7 , wherein the vent period comprises opening a valve of the negative pressure circuit to allow the negative pressure circuit to return to atmospheric pressure.
13. The wound therapy system of claim 7 , wherein the controller is further configured to estimate the volume of the wound by inputting the drawdown parameter and the leak rate parameter into a model that relates the volume of the wound to the drawdown parameter and the leak rate parameter.