Wound therapy system with wound volume estimation

Abstract

To provide a wound therapy system configured to estimate a volume for a wound site.SOLUTION: The volume of the wound is estimated using a dynamic pressure response measured during the instillation of fluid into the wound using the negative pressure wound therapy system. The previously estimated wound volume may be used to detect and prevent overfilling of the wound with fluid during future instillation events. For example, real-time pressure measurements can be compared to model data representing an expected pressure at a wound having a volume equal to a previously estimated wound volume, and the infusion is stopped if the observed pressure differs from the expected pressure. The total volume of fluid instilled into the wound can be compared to the previously estimated wound volume to prevent overfilling. The wound volume estimated based on instillation events can also be compared to wound volumes estimated using other methods to provide a more reliable wound volume estimate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates generally to wound therapy systems, and more particularly to wound therapy systems configured to estimate volume for a wound site. [Background technology]

[0002] Negative pressure wound therapy (NPWT) is a type of wound therapy that involves applying negative pressure to a treatment site to promote wound healing. Recent advances in NPWT wound healing involve applying topical fluids to the wound to act in combination with NPWT. However, determining the appropriate volume of infusion fluid to deliver to the wound can be difficult. Additionally, accurately monitoring and tracking the healing progress of the wound over time can be challenging. Therefore, it would be advantageous to provide a system and method that allows for accurate and reliable estimation of the available space at the wound site to which infusion fluid can be delivered and estimation of the healing progress of the wound site over time. Advantageously, such systems and methods would additionally allow such volume determination to be performed automatically by a controller, could be performed at any stage during the NPWT treatment, and would not require additional time and / or steps to perform as may be required in a typical NPWT treatment, could enable overfill detection and / or prevention during the fluid infusion cycle, and / or could account for changes in the type or size of the removal fluid canister used over the course of the NPWT treatment. Summary of the Invention

[0003] In one implementation of the present disclosure, a method includes operably connecting a first end of a fluid tube to a fluid canister and a pump of a therapy device and operably connecting a second end of the fluid tube to a wound dressing applied to a wound site. The pump is operated until a predetermined first negative pressure is detected. A first amount of fluid is infused into the wound site until a first predetermined target pressure is detected. Pressure is monitored during infusion of the first amount of fluid into the wound site. A volume of the first amount of fluid infused into the wound site is determined using pressure measurements obtained from the pressure monitored during infusion of the first amount of fluid into the wound site.

[0004] According to some embodiments, determining the volume of the first amount of fluid instilled at the wound site includes comparing the acquired pressure measurements with model pressure decay data. According to some embodiments, the model pressure decay data represents pressure decay in a container when a predetermined amount of fluid is instilled into the container having a known volume. According to some embodiments, the model pressure decay data includes pressure decay data for a plurality of containers having known volumes.

[0005] According to some embodiments, the determined volume of the first amount of fluid infused into the wound site is stored. According to some embodiments, the first predetermined target pressure is about 0 mmHg. According to some embodiments, the pump is operated until a second predetermined negative pressure is detected. According to some embodiments, the second amount of fluid is infused into the wound site until the second predetermined target pressure is detected. According to some embodiments, pressure is monitored during infusion of the second amount of fluid into the wound site.

[0006] According to some embodiments, the volume of the second amount of fluid instilled into the wound site is determined using pressure measurements obtained from the pressure monitored during instillation of the second amount of fluid into the wound site. According to some embodiments, the second predetermined target pressure is approximately 0 mmHg.

[0007] According to some embodiments, a first amount of fluid is instilled into the wound site at a predetermined flow rate. According to some embodiments, a second amount of fluid is instilled into the wound site at a predetermined flow rate. According to some embodiments, the determined volume of the second amount of fluid instilled into the wound site is stored. According to some embodiments, the rate of wound healing is determined by comparing the stored first volume with the stored second volume.

[0008] In one implementation of the present disclosure, a method for preventing overfilling of a wound site with fluid includes operably connecting a first end of a fluid tube to a fluid canister and a pump of a therapy device and operably connecting a second end of the fluid tube to a wound dressing applied to the wound site. The pump is operated to achieve a predetermined first negative pressure. Fluid is infused into the wound site. The pressure during infusion of the fluid into the wound site is monitored. Infusion of the fluid into the wound site is stopped in response to detection of the first predetermined target pressure.

[0009] According to some embodiments, the first predetermined target pressure is 0 mmHg. According to some embodiments, the volume of the wound site is estimated prior to instilling fluid into the wound site. According to some embodiments, model pressure decay data is obtained, the model pressure decay data representing pressure decay within a container as various amounts of fluid are instilled into the container having a volume equal to the estimated volume of the wound site. According to some embodiments, monitoring the pressure includes obtaining pressure measurements. According to some embodiments, the obtained pressure measurements are compared to the model pressure decay data in real time. According to some embodiments, an alarm is generated if the measured pressure does not correspond to the model pressure decay data.

[0010] According to some embodiments, a volume of fluid instilled into the wound site is determined. According to some embodiments, the volume of fluid instilled into the wound site is determined using pressure measurements obtained from pressure monitored during instillation of the fluid into the wound site. According to some embodiments, determining the volume of fluid instilled into the wound site includes comparing the obtained pressure measurements with model pressure decay data.

[0011] According to some embodiments, the second predetermined pressure is 0 mmHg. According to some embodiments, the estimated volume of the wound site is compared to a determined volume of fluid instilled into the wound site. According to some embodiments, an alarm is generated if the estimated volume of the wound site is not substantially the same as the determined volume of fluid instilled into the wound site.

[0012] In one implementation of the present disclosure, a wound therapy system includes a pump, a wound dressing configured to be applied to a wound site, fluid tubing fluidly connecting the pump to the wound dressing, and a controller configured to monitor pressure during infusion of fluid to the wound site and to determine a volume of fluid infused to the wound site using pressure measurements obtained from the monitored pressure during infusion of fluid to the wound site.

[0013] According to some embodiments, the controller is configured to determine a volume of fluid instilled into the wound by comparing the acquired pressure measurements with model pressure decay data. According to some embodiments, the controller is configured to store the determined volume of fluid instilled into the wound site. According to some embodiments, the controller is configured to determine a volume of fluid instilled into the wound site during each of one or more instillation events occurring during treatment of the wound site. According to some embodiments, the controller is configured to store each determined volume. According to some embodiments, the controller is configured to monitor healing of the wound site based on the stored determined volumes.

[0014] According to some embodiments, the wound therapy system further includes a source of infusion fluid. The controller is further configured to operate the pump to infuse fluid at the wound site. According to some embodiments, the controller is configured to stop infusion of fluid at the wound site when a first predetermined pressure is detected. According to some embodiments, the controller is configured to stop operation of the pump when a pressure of substantially 0 mmHg is detected. According to some embodiments, the controller is further configured to operate the pump to expel air from the wound site.

[0015] According to some embodiments, the controller is further configured to operate the pump to remove air from the wound site to achieve a predetermined negative pressure, the controller is configured to operate the pump to infuse fluid into the wound site upon detecting that the pressure equals the predetermined negative pressure, and the controller is configured to stop infusing fluid into the wound site upon detecting that the measured pressure equals the predetermined target pressure.

[0016] In one implementation of the present disclosure, a wound therapy system includes a pump, a wound dressing configured to be applied to a wound site, fluid tubing fluidly connecting the pump to the wound dressing, a source of infusion fluid, and a controller. The controller is configured to operate the pump to infuse the infusion fluid into the wound site and to monitor pressure during infusion of the fluid into the wound site. The controller is configured to stop operation of the pump in response to detecting a first predetermined pressure.

[0017] According to some embodiments, the predetermined pressure is 0 mmHg. According to some embodiments, the controller is configured to obtain an estimated volume of the wound site prior to operating the pump to infuse fluid at the wound site. According to some embodiments, the controller is configured to obtain pressure measurements based on pressure monitored during operation of the pump to infuse fluid at the wound site. According to some embodiments, the controller is configured to obtain model pressure decay data, the model pressure decay data representing pressure decay in a container as fluid is infused into the container having a volume equal to the estimated volume of the wound site. According to some embodiments, the controller is further configured to compare the pressure measurements to the model pressure decay data in real time.

[0018] According to some embodiments, an alarm is generated if the measured pressure does not correspond to the model pressure decay data. According to some embodiments, an estimated volume of the wound site is obtained by the controller by operating a pump to remove air from the wound site.

[0019] According to some embodiments, the controller is further configured to operate the pump to remove air from the wound site and monitor the pressure as air is removed from the wound site. The controller is further configured to stop operation of the pump when a predetermined negative pressure is detected. According to some embodiments, the controller is configured to operate the pump to infuse intravenous fluid into the wound site after the predetermined negative pressure is detected.

[0020] According to some embodiments, the controller is configured to estimate a volume of fluid infused at the wound site using pressure measurements obtained from the pressure monitored during infusion of the fluid at the wound site. According to some embodiments, the controller is configured to estimate a volume of fluid infused at the wound site by comparing the obtained pressure measurements with model pressure decay data. According to some embodiments, the model pressure decay data represents pressure decay in a container having a known volume during infusion of the fluid into the container.

[0021] According to some embodiments, the controller is configured to obtain an estimate of a volume of the wound site. According to some embodiments, the estimated volume of the wound site is compared to a determined volume of fluid instilled into the wound site. According to some embodiments, an alarm is generated if the estimated volume of the wound site is not substantially the same as the determined volume of fluid instilled into the wound site.

[0022] Those skilled in the art will appreciate that the Summary is merely illustrative and is not intended to be limiting in any way. Other aspects, inventive features, and advantages of the apparatus and / or processes described herein and defined solely by the claims will become apparent in the Detailed Description set forth herein and taken in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a block diagram of a negative pressure wound therapy system including a therapy device coupled to a wound dressing via a tube, according to an exemplary embodiment.

[0024] [Figure 2] FIG. 2 is a block diagram illustrating the negative pressure wound therapy system of FIG. 1 in more detail, according to an exemplary embodiment.

[0025] [Figure 3]FIG. 3 is a block diagram illustrating in greater detail the negative pressure circuit, removal fluid canister circuit, and wound site circuit of the negative pressure wound therapy system of FIG. 1, according to an exemplary embodiment.

[0026] [Figure 4] FIG. 4 is a block diagram illustrating a negative pressure wound therapy system, according to an exemplary embodiment.

[0027] [Figure 5] FIG. 5 is a flowchart of a method of using a negative pressure wound therapy system, according to an exemplary embodiment.

[0028] [Figure 6] FIG. 6 is a flowchart of a process for monitoring the healing progress of a wound site over time, according to an exemplary embodiment.

[0029] [Figure 7] FIG. 7 is a flowchart of a method of using a negative pressure wound therapy system, according to an exemplary embodiment.

[0030] [Figure 8] FIG. 8 is a flowchart of a method of using a negative pressure wound therapy system, according to an exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0031] overview Referring generally to the figures, a wound therapy system is shown according to various exemplary embodiments. The wound therapy system may include a therapy device and a wound dressing. The therapy device may include an infusion fluid canister, a removal fluid canister, a valve, an air pressure pump, an infusion pump, and a controller. The wound dressing may be applied to the patient's skin surrounding the wound. The therapy device may be configured to provide negative pressure wound therapy (NPWT) by delivering infusion fluid to the wound and maintaining the wound at negative pressure. The wound therapy device, wound dressing, and wound site components form a negative pressure circuit.

[0032] The controller may be configured to operate the air pressure pump, the infusion pump, and / or other controllable components of the therapy device. According to some embodiments, where the NPWT treatment provided using the NPWT system includes the infusion of an infusion fluid to a wound site, the controller may be configured to estimate the volume of the wound site and / or the volume of the infusion fluid to be delivered to the wound site based on a comparison of the observed dynamic pressure response as the fluid is infused to the wound site with model pressure response data. Because the dynamic pressure response is observed simultaneously with the infusion of the fluid to the wound site, the systems and methods described herein are configured to enable the controller to estimate the wound site volume without requiring additional steps and / or time that may otherwise be required to provide an infusion therapy treatment using the NPWT system.

[0033] According to some embodiments, a wound site volume estimate based on the dynamic pressure response observed during fluid infusion can be used to cross-check a wound site volume estimate obtained using any number of other methods, or can be cross-checked with a wound site volume estimate obtained using any number of other methods to provide a more reliable wound site volume estimate to the NPWT system. For example, in some embodiments, the controller can compare a wound site volume estimated based on the dynamic pressure response observed during fluid infusion with a wound site volume estimated based on a comparison of the dynamic pressure response observed during purging of negative pressure within all and / or selected portions of the negative pressure circuit.

[0034] In various embodiments, the controller may additionally or alternatively be configured to prevent and / or detect overfilling of the wound site with intravenous fluid during infusion. According to some such embodiments, the controller may use a previously obtained wound site volume estimate (e.g., a wound site volume estimate estimated during a previous infusion of fluid to the wound site, a wound site volume estimate based on a comparison of the dynamic pressure response observed during a purge of negative pressure from the negative pressure circuit, etc.) as a backstop value to which the volume of the amount of fluid infused at the wound site is compared to prevent overfilling of the wound site with intravenous fluid. In some embodiments, the previously obtained wound site volume estimate may additionally or alternatively be used to identify a model pressure decay curve representing the expected dynamic pressure response during infusion of intravenous fluid to the wound site to achieve a predetermined target pressure, e.g., measured at the wound site, in any one or more of the tubing connecting the wound site to a therapy device, in a removal fluid canister, at the therapy device, etc. In such an embodiment, the dynamic pressure response at the wound site is monitored in real time and compared to a model pressure decay curve, and the difference between the monitored pressure and the predicted pressure based on the model decay curve is used to alert the controller to a potential overfill situation that may need to be addressed.

[0035] In some embodiments, additionally or alternatively, the controller may estimate and monitor the volume of the wound site multiple times during wound treatment, and the controller determines the healing progress of the wound site based on changes in the estimated wound site volume over the course of the NPWT treatment. By monitoring the healing progress of the wound site, the controller may be configured to alert the user if healing of the wound site is not progressing as intended or expected. As will be appreciated, in some embodiments, monitoring changes in the estimated wound site volume over time can additionally advantageously provide the controller with more accurate values ​​that enable the controller to more accurately detect and / or prevent overfilling of the wound site with infusion fluid. These and other features of the wound therapy system are described in detail below.

[0036] Wound Therapy System 1 , a negative pressure wound therapy (NPWT) system 100 is shown according to an exemplary embodiment. The NPWT system 100 is shown to include a therapy device 102 fluidly connected to a wound dressing 112 via tubing 108 and tubing 110. According to various embodiments, the wound dressing 112 may be placed on or within a wound site 114 and adhered or sealed to the patient's skin 116 surrounding the wound site 114 using a drape layer 117. Some examples of wound dressings 112 that can be used in combination with the NPWT system 100 are described in detail in U.S. Pat. No. 7,651,484, granted January 26, 2010; U.S. Pat. No. 8,394,081, granted March 12, 2013; and U.S. patent application Ser. No. 14 / 087,418, filed November 22, 2013. The entire disclosures of each of these patents and patent applications are incorporated herein by reference.

[0037] As shown in the block diagram of FIG. 2, therapy device 102 generally includes air pressure pump 120, infusion pump 122, filter 128, and controller 118. Air pressure pump 120 may be fluidly coupled to removal fluid canister 106 (e.g., via conduit 136) and may be configured to draw a vacuum on canister 106 by pumping air from canister 106. In some embodiments, air pressure pump 120 is configured to operate in both a forward and reverse direction. For example, air pressure pump 120 can operate in a forward direction to pump air out of canister 106 and reduce the pressure within canister 106. Air pressure pump 120 can operate in a reverse direction to pump air into canister 106 and increase the pressure within canister 106. Air pressure pump 120 can be controlled by controller 118, which is described in more detail below.

[0038] The therapy device 102 may be configured to provide negative pressure wound therapy by reducing pressure at the wound site 114. The therapy device 102 may draw a vacuum (relative to atmospheric pressure) at the wound site 114 by removing wound exudate, air, and other fluids from the wound site 114. Wound exudate may include fluids that leave the patient's circulatory system and enter the area of ​​lesion or inflammation. For example, wound exudate may include water and dissolved solutes such as blood, plasma proteins, white blood cells, platelets, and red blood cells. Other fluids 121 removed from the wound site 114 may include infusion fluids 105 previously delivered to the wound site 114. Infusion fluids 105 may include, for example, irrigation fluids, prescription fluids, medicinal fluids, antibiotic fluids, or any other type of fluid that may be delivered to the wound site 114 during wound treatment. Infusion fluid 105 may be held in infusion fluid canister 104 and controllably dispensed to wound site 114 via tubing 108. In some embodiments, infusion fluid canister 104 is removable from therapy device 102 to allow canister 104 to be refilled and replaced as needed.

[0039] The infusion pump 122 may be fluidly connected to the infusion fluid canister 104 and the wound dressing 112 via the infusion tubing 108. The infusion pump 122 may be operated to deliver the infusion fluid 105 to the wound dressing 112 and the wound site 114 by pumping the infusion fluid 105 through the infusion tubing 108. The infusion pump 122 may be controlled by the controller 118, which is described in more detail below. According to some embodiments, the infusion pump 122 may be defined by all or a portion of the pneumatic pump 120.

[0040] The filter 128 can be located between the removal fluid canister 106 and the pneumatic pump 120 (e.g., along the conduit 136) so that air pumped from the canister 106 passes through the filter 128. The filter 128 may be configured to prevent liquids or solid particles from entering the conduit 136 and reaching the pneumatic pump 120. The filter 128 may include a bacterial filter that is hydrophobic and / or lipophilic, for example, so that aqueous and / or oily liquids bead on the surface of the filter 128. The pneumatic pump 120 may be configured to provide sufficient airflow through the filter 128 so that the pressure drop across the filter 128 is insubstantial (e.g., so that the pressure drop does not substantially interfere with the application of negative pressure from the therapy device 102 to the wound site 114).

[0041] The removal fluid canister 106 may be a component of the therapy device 102 configured to collect wound exudate and other fluids 121 removed from the wound site 114. In some embodiments, the removal fluid canister 106 is removable from the therapy device 102 to allow the canister 106 to be emptied and replaced as needed. A lower portion of the canister 106 may be filled with wound exudate and other fluids 107 removed from the wound site 114, and an upper portion of the canister 106 may be filled with air. The therapy device 102 may be configured to draw a vacuum within the canister 106 by pumping air from the canister 106. The reduced pressure within the canister 106 may be transferred to the wound dressing 112 and the wound site 114 via the tubing 110.

[0042] As shown in FIG. 1 , a tube valve 111 (e.g., a spring-loaded, duckbill, check valve, etc.) configured to prevent fluid flow from the removal fluid canister 106 to the wound site 114 may be positioned along the tube 110 at a location between the removal fluid canister 106 and the wound site 114.

[0043] 3, the removal fluid canister 106, the tubing 110, the conduit 136 extending between the pneumatic pump 120 and the removal fluid canister 106, and the wound site 114 are fluidly connected to define a negative pressure circuit 200. As described in more detail below, the volume of the tubing 110 and the volume of the conduit 136 define a known volume that can be easily subtracted from or factored into calculations of the volume(s) for the wound site 114. As shown in FIG. 2, according to various embodiments, a vent 132 may be provided through which a vacuum may be drawn within the negative pressure circuit 200.

[0044] As further described with reference to Figure 8, according to some embodiments, it may be desirable to check a volume estimated using any of the methods described herein against volume estimates obtained using other methods and / or from other sources, for example, a volume estimated based on measurements obtained during drawdown of a negative pressure circuit, as described in related, co-pending U.S. Provisional Patent Application No. 62 / 714,229, filed August 3, 2018, entitled WOUND THERAPY SYSTEM WITH WOUND VOLUME ESTIMATION, the entire disclosure of which is incorporated herein by reference. Thus, as shown in Figure 4, according to various embodiments, NPWT system 100 may optionally include one or more features configured to enable it to be used to estimate volume using any number of other methods, in addition to the various methods of estimating volume during fluid infusion described herein.

[0045] For example, as shown in FIG. 4, the NPWT system 100 may include features similar to those described with reference to the various systems described in related, co-pending U.S. Provisional Patent Application No. 62 / 714,229. In particular, according to some embodiments, the tube valve 111 described with reference to the embodiment of FIG. 1 may be modified such that the tube valve 111′ of the embodiment of FIG. 4 is configured to selectively allow and prevent fluid flow between the removal fluid canister 106 and the wound site 114, thereby allowing the negative pressure circuit 200 to be selectively fluidly divided into a removal fluid canister circuit (i.e., the portion of the negative pressure circuit located upstream of the tube valve 111′) and a wound site circuit (i.e., the portion of the negative pressure circuit located downstream of the tube valve 111′). Referring again to FIG. 4, according to some embodiments, the NPWT system 100 may also be provided with a calibrated leak system 113 configured to selectively control and measure airflow between the tube 110 and the ambient environment surrounding the therapy device 102. According to various embodiments, the calibrated leak system 113 can be selectively opened to allow air flow into the tube 110 at a known, predetermined rate.

[0046] 2, according to various embodiments, the controller 118 may be configured to operate various components of the therapy device 102. In particular, as described in more detail below, according to various embodiments, the controller 118 may be configured to control various components of the NPWT system 100 to perform one or more volume determination procedures, through which, for example, an estimated volume of the wound site 114 may be determined and healing progress of the wound site may be tracked. According to various embodiments, the controller 118 may be configured such that these procedures may be performed with minimal user intervention and / or input.

[0047] According to various embodiments, the NPWT system 100 may include various sensors. For example, in some embodiments, one or more pressure sensors 115 may be located in line within the tubing 110, in any one or more of the wound dressing 112, in the removal fluid canister 106, in the therapy device 102, in the pump 120, etc. to enable measurement of pressure at any one or more of the removal fluid canister 106, in the tubing 110, and / or at the wound site 114. Pressure measurements recorded by the pressure sensor(s) 115 may be communicated to the controller 118. According to various embodiments, the controller 118 may use the pressure measurements from the pressure sensor(s) 115 as inputs to various pressure testing and control operations performed by the controller 118.

[0048] In some embodiments, the therapy device 102 includes a user interface 126. The user interface 126 may include one or more buttons, dials, sliders, keys, or other input devices configured to receive input from a user. The user interface 126 may also include one or more display devices (e.g., LEDs, LCD displays, etc.), speakers, tactile feedback devices, or other output devices configured to provide information to the user. The user interface 126 may also display alerts generated by the controller 118. For example, the controller 118 may generate a "no canister" alert if the canister 106 is not detected.

[0049] In some embodiments, the therapy device 102 includes a data communication interface 124 (e.g., a USB port, a wireless transceiver, etc.) configured to transmit and receive data. The communication interface 124 may include a wired or wireless communication interface (e.g., a jack, an antenna, a transmitter, a receiver, a transceiver, a wire terminal, etc.) for implementing data communication with an external system or device. In various embodiments, communication may be direct (e.g., local wired communication or local wireless communication) or may be via a communication network (e.g., a WAN, the Internet, a cellular network, etc.). For example, the communication interface 124 may include a USB port or an Ethernet card and a port for transmitting and receiving data over an Ethernet-based communication link or network. In another example, the communication interface 124 may include a Wi-Fi transceiver for communicating over a wireless communication network, a cellular phone communication transceiver, or a mobile phone communication transceiver.

[0050] How to use 5, a flowchart detailing steps of a method 500 of using the NPWT system 100 is shown, according to an exemplary embodiment. As shown in FIG. 5, at step 502, the NPWT system 100 (e.g., as shown in FIG. 1) is provided, and the drape layer 117 and wound dressing 112 of the NPWT system 100 are positioned at the desired wound site 114 to be treated. According to some embodiments, as part of the initiation of treatment at step 502, and before proceeding with the remaining steps of the method 500, any number of different methods may be used to verify that the drape layer 117 and wound dressing 112 have been properly sealed around the wound site 114. For example, according to some embodiments, following operation of the air pressure pump 120 to remove air from the wound site 114, pressure may be monitored (e.g., using the pressure sensor 115) to verify that there is no unintended air leakage from the wound site 114. According to various embodiments, the pressure that may be monitored may be any one or more of the pressure in the tubing 110, the pressure in the removal fluid canister 106, the pressure at the therapy device 102, the pressure at the wound site 114, the pressure at the pump 120, etc. It will be appreciated that in other embodiments, this verification of a proper seal between the wound dressing 112 / drape layer 117 and the wound site 114 may alternatively be performed as part of and / or during a subsequent step of the method 500.

[0051] According to some embodiments, in addition to verifying the absence of leaks in the assembled NPWT system 100, step 502 may also optionally include acquiring model data. The model data represents the change in pressure over time as various volumes of infusion fluid are infused into a wound site under various clinically relevant conditions and conditions (e.g., different infusion rates, wound volumes, dressing / foam properties, dressing air leak rates, starting pressures, predetermined target pressures, etc.). Such model data may be generated using any number of different function approximators, statistical methods, machine learning systems, etc., or combinations thereof. The model data acquired in step 502 may include any number of different pressure decay curves, functions, lookup tables, etc., and may be acquired as pre-existing information input and stored by the controller and / or may be acquired and processed by the controller 118 during an optional initial training procedure performed by the controller 118 prior to using the NPWT system 100 to treat the wound 114 (e.g., before the start of method 500 or as part of the initial setup of the NPWT system 100 in step 502). Non-limiting examples of embodiments of training procedures in which such relationships may be generated by the controller 118 are outlined in related co-pending U.S. Provisional Patent Application No. 62 / 650,132, filed April 17, 2018, entitled WOUND THERAPY SYSTEM WITH WOUND VOLUME ESTIMATION, the entire disclosure of which is incorporated herein by reference. As will be appreciated, in embodiments in which the wound site 114 volume is additionally estimated during purging of negative pressure within all or a portion of the negative pressure circuit 200, model data representing pressure changes over time as ambient air is allowed to flow into all or a portion of the negative pressure circuit 200 under various clinically relevant conditions and conditions may additionally be obtained in a substantially similar manner.

[0052] Upon completing the setup of the NPWT system 100 in step 502, the pneumatic pump 120 is operated (manually or using the controller 118) to achieve a predetermined negative pressure in step 504. After the predetermined target pressure is achieved, the infusion pump 122 (which may be the same as the pneumatic pump 120 or may be different) is operated to infuse the infusion fluid 105 into the wound site 114 in step 506. The infusion fluid 105 is infused into the wound site 114 in step 506 until the predetermined target pressure is achieved. According to various embodiments, the target pressure and / or the predetermined negative pressure may correspond to pressure measured in any one or more of the tubing 110, the removal fluid canister 106, the therapy device 102, the wound site 114, the pump 120, etc. According to various embodiments, the predetermined target pressure may be between about -15 mmHg and about 15 mmHg, more specifically between about -5 mmHg and 5 mmHg, and even more specifically about 0 mmHg.

[0053] At step 508, pressure decay (such pressure decay may be an increase in pressure over time) monitored at any one or more of the tubing 110, removal fluid canister 106, therapy device 102, wound site 114, etc. during infusion of the infusion fluid 105 into the wound site 114 at step 506 may be used to estimate the volume of the wound site 114. According to some embodiments, the wound site 114 volume estimation may be based on a comparison of the dynamic pressure measured during the fluid infusion at step 506 with model pressure decay data obtained before or during step 502. Because the wound site 114 volume estimated at step 508 is estimated based on the pressure decay observed during infusion of the infusion fluid 105 into the wound site 114 at step 506, as previously described, the method 500 illustrated by the flowchart of FIG. 5 does not require additional steps and / or time that may otherwise be required to infuse the infusion fluid 105 into the wound site 114. At step 510, the wound site 114 volume estimated at step 508 may optionally be stored for future use.

[0054] Following the estimation of the wound site 114 volume in step 508, the NPWT system 100 may continue to be used to provide NPWT treatment according to any number of different protocols in step 512. As shown in step 512 of method 500 of FIG. 5 , according to various embodiments, the NPWT treatment may continue with one or more cycles of negative pressure application and fluid instillation using the NPWT system 100, with the step 508 of estimating the wound site 114 volume optionally being repeated after some, all, or neither of the additional steps 504 of applying negative pressure to the wound site 114 and / or the step 506 of instilling an instillation fluid 105 into the wound site 114.

[0055] The wound site 114 volume estimated using the method 500 of FIG. 5 may be used for any number of different purposes. For example, as described above, according to some embodiments, the wound site 114 volume estimated during the infusion phase of the NPWT treatment may be advantageously used to track the progress of wound site 114 healing. With reference to FIG. 6, a flowchart of a method 600 for monitoring wound site 114 healing by using estimated wound site 114 volume measurements obtained at multiple time points during the course of an NPWT treatment using the NPWT system 100 is shown, according to an exemplary embodiment. As shown in FIG. 6, at step 602, an initial wound site 114 volume estimate may be recorded to serve as a baseline, and subsequent wound site 114 volume estimates are compared to the baseline to track healing progress. According to various embodiments, the estimation of the initial volume of the wound site 114 at step 602 may be performed by (or as) step 508 of the method 500 described with reference to FIG. 5.

[0056] At step 604, the volume of the wound site 114 is estimated and recorded at one or more additional times during treatment (e.g., once per day) following the initial wound site 114 volume estimation at step 602, and the one or more times at which such wound site 114 volume is estimated and the determined wound site 114 volume values ​​are stored as data points in the memory of the therapy device 102 and / or presented to the user as an output of the therapy device 102 (e.g., via the communication interface 124 or the user interface 126). In some embodiments, the estimated wound volume may be plotted as a function of time.

[0057] The additional wound site 114 volumes estimated at one or more additional times over the course of treatment in step 604 may be estimated by any number of different processes. For example, according to various embodiments, the estimation of the wound site 114 volume in step 604 may be performed by (or as) step 508 of method 500 of FIG. 5 during a subsequent occurrence of fluid infusion as part of the continued NPWT treatment in step 512. Alternatively or additionally, one or more of the additional wound site 114 volumes estimated in step 604 may be obtained by any other method, for example, based on the dynamic pressure response observed within the negative pressure circuit 200 of the NPWT system 100 during a purge event.

[0058] As additional wound site 114 volume estimates are obtained in step 604, changes in the estimated wound site 114 volume over time may be used in step 606 to determine healing progress of the wound site 114. For example, step 606 may include comparing the wound site 114 volume estimate obtained in step 604 with one or more previous estimates of wound site 114 volume (obtained in either step 604 or step 602) to identify changes in wound site 114 volume. In some embodiments, step 606 may additionally include determining a rate at which the wound site 114 is healing based on changes in the estimated wound site 114 volume over time. In some embodiments, step 606 may include extrapolating or predicting the time at which the wound site 114 will be completely healed based on a series of wound site 114 volume estimates stored by the controller 118. For example, step 606 may include predicting the time at which the estimated wound site 114 volume will reach zero (or another threshold) based on the initial wound site 114 volume estimated in step 1002 and a series of additional wound site 114 volumes estimated in step 604.

[0059] According to some embodiments, in addition to or as an alternative to using wound site 114 volume estimates to monitor wound site 114 healing progress (e.g., as described with reference to method 600 of FIG. 6 above), wound site 114 volume estimates may be used to detect and / or prevent overfilling of the wound site 114 with infusion fluid 105 during infusion of the infusion fluid 105 into the wound site 115.

[0060] Referring to the method 700 for preventing and / or detecting overfilling of a wound site 115 with infusion fluid 105 during an infusion event shown in Figure 7, the method 700 begins with step 702 of obtaining an initial wound site 114 volume estimate. In embodiments in which the infusion event of Figure 7 corresponds to the infusion of fluid during continued NPWT treatment of step 512 described with reference to method 500 of Figure 5, the initial wound site 114 volume estimate obtained in step 702 may be equal to the wound site 114 volume estimated in step 508 of method 500 of Figure 5. In embodiments in which the method 700 of Figure 7 is performed subsequent to a previous iteration of method 700 of Figure 7, the wound site 114 volume estimate obtained in step 702 may correspond to the wound site 114 volume estimated in step 720 of the previous iteration of method 700. In still other embodiments, the wound site 114 volume estimate obtained in step 702 may be obtained in any number of other ways (e.g., the volume estimated in step 810 of method 800 of FIG. 8).

[0061] At step 704, the pneumatic pump 120 is operated to achieve a predetermined negative pressure in any one or more of the tubing 110, removal fluid canister 106, therapy device 102, wound site 114, pump 120, etc., followed by instillation of infusion fluid 105 into the wound site 114 at step 706. As shown in FIG. 7 , as fluid is instilled into the wound site 114, according to some embodiments, the pressure in any one or more of the tubing 110, removal fluid canister 106, therapy device 102, wound site 114, pump 120, etc. may optionally be monitored in real time at step 708. In such embodiments, this measured real-time pressure may be compared to a model pressure decay curve representing a volume corresponding to the estimated wound site 114 volume obtained at step 702 (such as the model pressure decay curve described with reference to step 502 in method 500 of FIG. 5 above) and the situation as the infusion fluid 105 is instilled into the wound site at step 706. 7, in the event that the measured real-time pressure decay does not correspond to the expected pressure decay of the model pressure decay curve, the controller 118 may generate a warning to the user in step 710. In the event that the real-time pressure decay is changing at a rate greater than expected, the controller 118 may also optionally stop the drip of infusion fluid 105 to the wound site 114 in step 712 to prevent overfilling with fluid.

[0062] As will be appreciated, the measured real-time pressure decay may vary from the expected pressure decay predicted by the model data for any number of reasons. For example, in embodiments in which the volume of the wound site 114 has decreased since the volume of the wound site 114 was last estimated, it is expected that the observed pressure decay as a result of the now smaller sized wound site 114 will vary from the expected pressure decay predicted by the model data. Accordingly, in some embodiments, the controller 118 may be configured to generate an alarm at step 710 and / or stop the infusion of the infusion fluid 105 at step 712 only in the event that the difference between the measured pressure decay and the expected pressure decay exceeds a predetermined threshold. According to some embodiments, this threshold may correspond to a difference of more than about ±15 percent, more specifically, more than about ±10 percent, and even more specifically, more than about ±5%.

[0063] If no difference between the real-time pressure measurement and the expected pressure measurement is detected in step 708 (or the difference does not exceed a predetermined threshold), then in step 714 it is determined whether a predetermined target pressure has been achieved in any one or more of the tubing 110, removal fluid canister 106, therapy device 102, wound site 114, pump 120, etc. If the measured pressure is determined to be substantially equal to the predetermined target pressure, the drip of infusion fluid 1045 is stopped in step 716. According to various embodiments, the predetermined target pressure in step 714 may be between about −15 mmHg and about 15 mmHg, more specifically between about −5 mmHg and 5 mmHg, and even more specifically about 0 mmHg.

[0064] According to some embodiments, if the target pressure has not yet been achieved at step 714, step 706 of instilling fluid into the wound site 114 (and optionally step 708 of comparing the monitored pressure with the predicted pressure based on model data) may be repeated until it is determined at step 714 that the target pressure has been achieved.

[0065] However, as shown in FIG. 7 , according to some embodiments, method 700 may optionally include step 718, which may provide an additional layer of safety protection against overfilling of the NPWT system 100 in the event that the comparison of the measured wound site 114 pressure to the target pressure is insufficient to detect a potential overfill situation. In such embodiments, in step 718, the total volume of infusion fluid 105 infused into the wound site 114 since the start of step 706 may be compared to the wound site 114 volume estimate obtained in step 702, and the infusion of infusion fluid 105 is stopped in step 716 if it is determined that the volume of infused fluid is substantially the same as the estimated wound site 114 volume. As will be appreciated, by preventing the infusion of an amount of infusion fluid 105 in a volume that exceeds the estimated wound site 114 volume, step 718 of method 700 of FIG. 7 provides an additional level of protection against overfilling of the NPWT system 100. Alternatively, if the volume of instilled infusion fluid 105 is less than the estimated wound site 114 volume, the method 700 may continue instilling fluid into the wound site 114 at step 706 .

[0066] According to some embodiments, at step 720, the current volume of the wound site 114 may optionally be estimated based on the most recent infusion of fluid during step 706, and at step 722, this most recent estimated wound site 114 volume is stored for any number of future uses (e.g., for future infusion of fluid according to method 700 of FIG. 7, for monitoring healing of the wound site 114 according to method 600 of FIG. 6, etc.). In situations where the infusion of fluid is stopped at step 716 in response to determining that the target pressure has been achieved at step 714, the wound site 114 volume may be estimated in a manner similar to that described with reference to step 508 of method 500 of FIG. 5, wherein pressure decay observed in any one or more of the tubing 110, removal fluid canister 106, therapy device 102, wound site 114, pump 120, etc. during the infusion of fluid is compared to model pressure decay data to identify a corresponding volume of the wound site 114. If the drip of the drip fluid 105 is stopped in step 716 in response to determining in step 718 that the volume of the drip fluid is substantially equal to or greater than the estimated wound site 114 volume, then, according to some embodiments, the wound site 114 volume estimated in step 720 may correspond to the previous wound site 114 volume estimate.

[0067] As mentioned above, according to some embodiments, it may be desirable to check a wound site 114 volume estimated during infusion of fluid into the wound site 114 (e.g., as described with reference to method 500 of FIG. 5 and / or method 700 of FIG. 7 ) against wound site 114 volume estimates obtained by any number of other different methods. With reference to FIG. 8 , an exemplary embodiment of such a method 800 is shown in which a wound site 114 volume estimate obtained during fluid infusion is checked against a wound site 114 volume estimated by another method (or vice versa). More specifically, in method 800 illustrated by the flowchart of FIG. 8 , a wound site 114 volume estimate based on dynamic pressure responses observed during purging of various portions of the negative pressure circuit 200 of the NPWT system 100, for example, according to the embodiment described with reference to FIG. 4 , is compared to a wound site 114 volume estimate based on fluid infusion to provide a more reliable wound site 114 volume estimate to the NPWT system 100.

[0068] 8 , according to one embodiment of method 800, in step 802, air pressure pump 120 is operated to achieve a desired negative pressure in negative pressure circuit 200. As will be appreciated, in embodiments in which tubing valve 111′ is in a closed configuration, step 802 may additionally include the step of opening tubing valve 111′. When the desired negative pressure is achieved in negative pressure circuit 200, negative pressure circuit 200 is purged by allowing air from the ambient environment to enter negative pressure circuit 200 (e.g., via calibrated leak system 113) until a predetermined threshold pressure is achieved in negative pressure circuit 200. As negative pressure circuit 200 is purged during step 804, pressure decay in negative pressure circuit 200 is monitored (e.g., using pressure sensor(s) 115).

[0069] When a predetermined threshold pressure is achieved within the negative pressure circuit 200, the air pressure pump 120 is again operated in step 806 to remove air from the negative pressure circuit 200 to achieve the desired negative pressure in the negative pressure circuit 200. When this desired negative pressure is achieved, the tube valve 111' is closed in step 808, thereby fluidly isolating the removal fluid canister circuit from the wound site circuit.

[0070] At step 810, the removal fluid canister circuit is purged by allowing air from the surrounding environment to flow into the removal fluid canister circuit (e.g., via the calibrated leak system 113) until a predetermined threshold pressure is achieved in the removal fluid canister circuit. As the removal fluid canister circuit is purged during step 810, the pressure decay in the removal fluid canister circuit is monitored (e.g., using the pressure sensor 115). At step 812, a first volume of the wound site 114 is estimated using the pressure decay observed in the negative pressure circuit 200 and the removal fluid canister circuit during steps 804 and 810, respectively. More specifically, the volume of the wound site 114 is calculated by comparing the pressure decay observed in steps 804-810 with model pressure decay data to identify corresponding volumes representing the volumes of the negative pressure circuit 200 and the removal fluid canister circuit, from which the wound site 114 may then be estimated. Non-limiting examples of additional method and / or system embodiments in which the wound site 114 volume may be calculated using the pressure decay observed during purging of part or all of the negative pressure circuit 200, as described with reference to steps 802-812 of method 800 of FIG. 8, are outlined in related co-pending U.S. Provisional Patent Application No. 62 / 714,229, filed August 3, 2018, entitled WOUND THERAPY SYSTEM WITH WOUND VOLUME ESTIMATION, the entire disclosure of which is incorporated herein by reference.

[0071] At step 814, infusion fluid 105 is infused into the wound site 114 until a predetermined pressure is achieved in any one or more of the tubing 110, removal fluid canister 106, therapy device 102, wound site 114, pump 120, etc., similar to that described with reference to step 506 of method 500 of Figure 5. At step 816, a second wound site 114 volume is estimated in a manner similar to that described with reference to step 508 of method 500 of Figure 5 based on pressure decay observed in any one or more of the tubing 110, removal fluid canister 106, therapy device 102, wound site 114, pump 120, etc., during the infusion of fluid into the wound site 114 at step 814. As will be appreciated, according to some embodiments, steps 814 and 816 may optionally be performed before steps 810 and 812, or alternatively, may be performed simultaneously with steps 810 and 812.

[0072] In step 818, the first wound site 114 volume estimated in step 812 is compared to the second wound site 114 volume estimated in step 816. If it is determined in step 818 that the first volume and the second volume are not substantially similar to one another, an alert may be generated in step 820. If it is determined in step 818 that the first volume and the second volume are substantially similar to one another, then in step 822, one, both, or an average of the first wound site 114 volume estimate and the second wound site 114 volume estimate is stored. As will be appreciated, any measure of similarity may be used to determine whether the first volume and the second volume are substantially similar to one another in step 818. According to some embodiments, the first volume and the second volume may be determined to be substantially similar to one another in step 818 if they differ from one another by no more than about 15 percent, more specifically no more than about 10 percent, and even more specifically no more than about 5 percent.

[0073] As will be appreciated, method 800 of FIG. 8 may be performed any number of times and at any time during an NPWT treatment provided using NPWT system 100. For example, according to some embodiments, method 800 is performed upon initial use of NPWT system 100, after which NPWT system 100 may be operated according to any of the methods disclosed herein or any other number of different NPWT treatments or other treatments or protocols. In embodiments in which method 800 of FIG. 8 is followed by method 700 of FIG. 7, the wound site 114 volume estimate obtained in step 702 during the initial iteration of method 700 may correspond to the wound site 114 volume estimate stored in step 820 of method 800. In subsequent iterations of method 700, the wound site 114 volume estimate obtained in step 702 may correspond to the wound site 114 volume stored in step 722 during the immediately preceding iteration of method 700.

[0074] In other embodiments, some or all of the method 800 of Figure 8 may be repeated any desired number of times. For example, in some embodiments, a cross-check of the wound site 114 volume estimated based on the purge events of steps 804 and 810 with the wound site 114 volume estimated based on fluid dripping of step 814 may be desired for each iteration of the method 800; in these embodiments, the method 800 of Figure 8 may be repeated in its entirety for each iteration. In other embodiments, it may be desirable to alternate between estimating the wound site 114 volume based on the purge events of steps 804 and 810 and estimating the wound site 114 volume based on fluid dripping of step 814. Additionally, according to various embodiments (including the embodiment of FIG. 8 above), some or all of the iterations of method 800 of FIG. 8 may optionally incorporate some or all of steps 708, 710, 712, 714, 716, 718, and 720 of method 700 of FIG. 700 between steps 815 and 816. According to various embodiments, method 600 of monitoring wound site 114 healing of FIG. 6 may also be incorporated into any of the methods disclosed herein.

[0075] Generally, the volume of the wound site 114 is defined by the entire interior extending between the wound site 114 and the drape layer 117 attached to the skin 116 surrounding the wound site 114. The various points during treatment using the NPWT system 100 that are located within and define the wound site volume may be any one or any combination of the wound dressing 112, the fluid 121, and / or the dead space 119. As will be appreciated, unless the wound dressing 112 is changed during treatment, the volume of the wound site 114 volume occupied by the wound dressing 112 will generally remain unchanged over the course of treatment, however, the portion of the wound site 114 volume occupied by the fluid 121 and / or the dead space 119 may change over time.

[0076] As will be appreciated, according to various embodiments, the controller 118 may be programmed to enable the NPWT system 100 to determine a volume for the wound site 114 using any or all of the methods described herein.

[0077] Configuration of an exemplary embodiment The construction and configuration of the systems and methods shown in the various exemplary embodiments are merely exemplary. While only a few embodiments are described in detail in this disclosure, many modifications are possible (e.g., variations in the size, dimensions, structure, shape, and proportions of various elements, parameter values, mounting configurations, material use, color, orientation, etc.). For example, the position of elements can be reversed or varied, and the nature or number or location of distinct elements can be changed or varied. Accordingly, all such modifications are intended to be within the scope of this disclosure. The order or sequence of any process or method steps can be varied or re-ordered according to alternative embodiments. Other substitutions, modifications, changes, and omissions can be made in the design, operating conditions, and configuration of the exemplary embodiments without departing from the scope of this disclosure.

[0078] The present disclosure contemplates methods, systems, and program products on any machine-readable medium for accomplishing various operations. Embodiments of the present disclosure can be implemented using existing computer processors, by dedicated computer processors for suitable systems incorporated for this or another purpose, or by hardwired systems. Embodiments within the scope of the present disclosure include program products including machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media may be any available medium that can be accessed by a general-purpose or special-purpose computer or other machine with a processor. By way of example, such machine-readable media may include RAM, ROM, EPROM, EEPROM, CD-ROM, or other optical disk storage, magnetic disk storage, or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of machine-executable instructions or data structures and that can be accessed by a general-purpose or special-purpose computer or other machine with a processor. Combinations of the above are also included within the scope of machine-readable media. Machine-executable instructions include, for example, instructions and data that cause a general-purpose computer, special-purpose computer, or special-purpose processing machine to perform a certain function or group of functions.

[0079] While the figures show a particular order of method steps, the order of steps may differ from that shown. Also, two or more steps may occur simultaneously or with partial concurrence. Such variations depend on the software and hardware systems selected and on the designer's choice. All such variations are within the scope of this disclosure. Similarly, software implementations may be accomplished with standard programming techniques using rule-based logic and other logic to accomplish the various connection, processing, comparison, and decision steps.

Claims

1. 1. A method comprising: fluidly connecting a fluid tube to the fluid canister, a pump of the therapy device, and a wound dressing applied to the wound site; operating the pump until a predetermined first negative pressure is detected; instilling a first amount of fluid into the wound site until a first predetermined target pressure is detected; monitoring pressure during instillation of the first amount of fluid into the wound site; and determining a volume of the first quantity of fluid instilled into the wound site using pressure measurements obtained from the pressure monitored during the instillation of the first quantity of fluid into the wound site.

2. The method of claim 1 , wherein determining the volume of the first amount of fluid instilled into the wound site comprises comparing the obtained pressure measurements with model pressure decay data.

3. The method of claim 2 , wherein the model pressure decay data represents pressure decay within a container having a known volume when a predetermined amount of fluid is instilled into the container.

4. The method of claim 3 , wherein the model pressure decay data includes pressure decay data for a plurality of vessels having known volumes.

5. The method of claim 1 , further comprising storing the determined volume of the first amount of fluid instilled into the wound site.

6. The method of claim 1 , wherein the first predetermined target pressure is approximately 0 mmHg.

7. The method of claim 5 , further comprising operating the pump until a predetermined second negative pressure is detected.

8. 8. The method of claim 7, further comprising instilling a second amount of fluid into the wound site until a second predetermined target pressure is detected.

9. The method of claim 8, further comprising monitoring pressure during instillation of the second amount of fluid into the wound site.

10. 10. The method of claim 9, further comprising determining a volume of the second amount of fluid instilled into the wound site using pressure measurements obtained from the pressure monitored during the instillation of the second amount of fluid into the wound site.

11. 10. The method of claim 9, wherein the second predetermined target pressure is approximately 0 mmHg.

12. The method of claim 1 , wherein the first amount of fluid is instilled into the wound site at a predetermined flow rate.

13. The method of claim 1 , wherein the pressure monitored during instillation of the first amount of fluid into the wound site is the pressure at the wound site.

14. The method of claim 10, further comprising storing the determined volume of the second amount of fluid instilled into the wound site.

15. 14. The method of claim 13, further comprising determining a rate of wound healing by comparing the stored first volume with the stored second volume.

16. 1. A method for preventing fluid overfilling of a wound site, comprising: fluidly connecting a fluid tube to the fluid canister, a pump of the therapy device, and a wound dressing applied to the wound site; operating the pump to achieve a predetermined first negative pressure; instilling a fluid into the wound site; monitoring pressure during infusion of the fluid into the wound site; and ceasing the drip of the fluid to the wound site in response to a first predetermined target pressure being detected.

17. 17. The method of claim 16, wherein the first predetermined target pressure is 0 mmHg.

18. 17. The method of claim 16, wherein the volume of the wound site is estimated prior to the instillation of the fluid into the wound site.

19. 18. The method of claim 17, further comprising obtaining model pressure decay data, the model pressure decay data representing pressure decay within a container having a volume equal to the estimated volume of the wound site when various amounts of fluid are instilled into the container.

20. 21. The method of claim 20, wherein monitoring pressure comprises obtaining a measurement of pressure at the wound site.

21. 21. The method of claim 20, wherein the acquired pressure measurements are compared in real time with the model pressure decay data.

22. 22. The method of claim 21, wherein an alarm is generated if the measured pressure does not correspond to the model pressure decay data.

23. 17. The method of claim 16, further comprising determining the volume of the fluid instilled into the wound site.

24. 24. The method of claim 23, wherein the volume of the fluid instilled into the wound site is determined using pressure measurements taken during instillation of the fluid into the wound site.

25. 25. The method of claim 24, wherein determining the volume of the fluid instilled into the wound site comprises comparing the obtained pressure measurements with model pressure decay data.

26. 26. The method of claim 25, wherein the model pressure decay data represents the pressure decay within a container having a known volume when a predetermined amount of fluid is instilled into the container.

27. 27. The method of claim 26, wherein the model pressure decay data includes pressure decay data for a plurality of vessels having different known volumes.

28. 24. The method of claim 23, wherein the volume of the wound site is estimated prior to the instillation of the fluid into the wound site.

29. 29. The method of claim 28, wherein the second predetermined pressure is 0 mmHg.

30. 30. The method of claim 29, wherein the estimated volume of the wound site is compared to the determined volume of the fluid instilled into the wound site.

31. 31. The method of claim 30, wherein an alarm is generated if the estimated volume of the wound site is not substantially the same as the determined volume of the fluid instilled into the wound site.

32. 1. A wound therapy system comprising: A pump and a wound dressing configured to be applied to a wound site; a fluid tube fluidly connecting the pump to the wound dressing; a controller, monitoring the pressure during instillation of fluid into the wound site; and determining a volume of the fluid instilled into the wound site using pressure measurements obtained from the pressure monitored during the instillation of the fluid into the wound site; With a controller configured as A wound therapy system comprising:

33. 33. The wound therapy system of claim 32, wherein the controller is configured to determine the volume of the fluid instilled into the wound by comparing the acquired pressure measurements with model pressure decay data.

34. 33. The wound therapy system of claim 32, wherein the controller is configured to store the determined volume of the fluid instilled at the wound site.

35. 33. The wound therapy system of claim 32, wherein the controller is configured to determine a volume of fluid instilled into the wound site during each of one or more instillation events occurring during treatment of the wound site.

36. 36. The wound therapy system of claim 35, wherein the controller is configured to store each of the determined volumes.

37. 37. The wound therapy system of claim 36, wherein the controller is configured to monitor healing of the wound site based on the stored determined volumes.

38. 33. The wound therapy system of claim 32, further comprising a source of infusion fluid, the controller further configured to operate the pump to infuse the fluid into the wound site.

39. 39. The wound therapy system of claim 38, wherein the controller is configured to stop the dripping of the fluid into the wound site when a first predetermined pressure is detected.

40. 39. The wound therapy system of claim 38, wherein the controller is configured to stop the operation of the pump when a pressure of substantially 0 mmHg is detected.

41. 33. The wound therapy system of claim 32, wherein the controller is further configured to operate the pump to remove air from the wound site.

42. 39. The wound therapy system of claim 38, wherein the controller is further configured to operate the pump to exclude air from the wound site.

43. 33. The wound therapy system of claim 32, further comprising a source of infusion fluid.

44. The controller: operating the pump to remove air from the wound site to achieve a predetermined negative pressure; activating the pump to infuse fluid into the wound site upon detecting that the pressure is equal to the predetermined negative pressure; and and ceasing the infusion of the fluid to the wound site upon detecting that the measured pressure is equal to a predetermined target pressure.

44. The wound therapy system of claim 43, further configured to:

45. 1. A wound therapy system comprising: A pump and a wound dressing configured to be applied to a wound site; a fluid tube fluidly connecting the pump to the wound dressing; a source of intravenous fluid; a controller, operating the pump to infuse the infusion solution into the wound site; monitoring the pressure during infusion of the infusion solution into the wound site; and and ceasing said operation of said pump in response to said detection of a first predetermined pressure. With a controller configured as A wound therapy system comprising:

46. 46. ​​The wound therapy system of claim 45, wherein the predetermined pressure is 0 mmHg.

47. 46. ​​The wound therapy system of claim 45, wherein the controller is configured to obtain an estimated volume of the wound site before operating the pump to infuse fluid into the wound site.

48. 48. The wound therapy system of claim 47, wherein the controller is configured to obtain pressure measurements based on the pressure monitored during the operation of the pump to infuse intravenous fluid into the wound site.

49. 49. The wound treatment system of claim 48, wherein the controller is configured to obtain model pressure decay data, the model pressure decay data representing pressure decay within a container having a volume equal to the estimated volume of the wound site when intravenous fluid is instilled into the container.

50. 50. The wound therapy system of claim 49, wherein the controller is further configured to compare the pressure measurements with the model pressure decay data in real time.

51. 51. The wound therapy system of claim 50, wherein an alarm is generated if the measured pressure does not correspond to the model pressure decay data.

52. 52. The wound therapy system of claim 51, wherein the estimated volume of the wound site is obtained by the controller by operating the pump to exclude air from the wound site.

53. The controller: operating the pump to remove air from the wound site; monitoring the pressure as air is expelled from the wound site; and When a predetermined negative pressure is detected, the pump is stopped.

46. ​​The wound therapy system of claim 45, further configured to:

54. 54. The wound therapy system of claim 53, wherein the controller is configured to operate the pump to infuse the infusion solution into the wound site after the predetermined negative pressure is detected.

55. 55. The wound therapy method of claim 54, wherein the controller is configured to estimate a volume of the instilled fluid at the wound site using pressure measurements obtained from the pressure monitored during instillation of the fluid at the wound site.

56. 56. A wound therapy method according to claim 55, wherein the controller is configured to compare the obtained pressure measurements with model pressure decay data to estimate the volume of the instilled fluid at the wound site.

57. 57. A wound therapy method according to claim 56, wherein the model pressure decay data represents the pressure decay within a container having a known volume during instillation of a fluid into the container.

58. 58. A wound therapy method according to claim 57, wherein the controller is configured to obtain an estimate of the volume of the wound site.

59. 59. A wound therapy method according to claim 58, wherein the estimated volume of the wound site is compared to a determined volume of the instilled fluid in the wound site.

60. 60. The wound therapy method of claim 59, wherein an alarm is generated if the estimated volume of the wound site is not substantially the same as the determined volume of the instilled fluid at the wound site.

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