A bandage has a first sheet overlying a wound and located adjacent to it and a top sheet overlying the first sheet. The first sheet has a plurality of discrete passageways overlying the wound and adapted to communicate negative pressure established by a negative pressure source to the wound.

Dressings, systems, and methods are disclosed for treating tissue with reduced pressure. A dressing for distributing reduced pressure to a tissue site includes a plurality of liquid-impermeable layers that are stacked and a plurality of spacers disposed at least partially between adjacent liquid-impermeable layers. The plurality of liquid-impermeable layers are fenestrated at least in part. The plurality of spacers and plurality of liquid-impermeable layers form a plurality of flow paths for allowing fluid flow under reduced pressure. Adjacent layers of the plurality of liquid-impermeable layers are stacked without foam between at least a majority of coextensive surfaces. Other dressings, systems, and methods are disclosed.

Foam wound inserts with high-density and low-density regions, methods for making wound inserts, wound-treatment methods, and wound-treatment systems.

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.

A volume of a wound is estimated using a dynamic pressure response measured during instillation of fluid to the wound using a negative pressure wound therapy system. A previously estimated wound volume may be used to detect and prevent overfill of fluid to the wound during future instillation events. For example, real-time pressure measurements may be compared to model data representative of expected pressure at a wound having a volume equal to the previously estimated wound volume, with instillation being stopped if the observed pressure varies from the expected pressure. A comparison of a total volume of fluid instilled to the wound may also be compared to the previously estimated wound volume to prevent overfill. The comparison of wound volume estimated based on an instillation event may also be compared to a wound volume estimated using other methods to provide a higher confidence wound volume estimate.

A portable negative pressure wound therapy system includes a dressing assembly for positioning over a wound to apply a negative pressure to the wound and a canister assembly. The canister assembly includes a control unit having a vacuum source and a controller and a collection canister in communication with the dressing assembly operable to receive fluid from the wound. The collection canister has a filter assembly having a filter and a passageway between the filter and a wall of the collection canister. The collection canister also includes a canister interface having a suction port, an inlet port, and a channel. The vacuum source draws air through the suction port from the channel which draws air from the passageway connected to the channel, the air in the passageway is drawn from the collection canister through the filter, and the air in the collection canister is drawn through the inlet port.

In some embodiments, a wound dressing that incorporates a number of sensors or sensors separate from the wound dressing can be utilized in order to monitor characteristics of a wound as it heals or to identify one or more risk factors or conditions that may precipitate a wound. In some implementations, a wound dressing configured to be positioned in contact with a wound includes a substantially flexible substrate supporting one or more sensors. The one or more sensors can include temperature sensors, conductivity sensors, multispectral optical measurements sensors, sensors, pressure sensors, colorimetric sensors, optical sensors, ultraviolet (UV) sensors, or infrared (IR) sensors.

A method and apparatus are disclosed for determining status of a canister of a topical negative pressure (TNP) system. The method includes the steps of monitoring pressure provided by a pump element of the TNP system, determining at least one characteristic associated with the monitored pressure and determining status of at least one parameter associated with a canister of the TNP system responsive to the determined characteristics.

A wound exudate management system includes a pump for generating negative pressure, a dressing for covering and protecting a wound of a user, a tube including an interior lumen, the tube disposed between the pump and the dressing such that the pump and the dressing are in fluid communication via the interior lumen. The dressing includes an adhesive layer for adhering the dressing adjacent the wound, a wound contact layer, a pressure dispersion layer, a plurality of layers of absorbent material disposed between the wound contact layer and the pressure dispersion layer, a backing layer having a first surface and a second surface, the first surface of the backing layer being adjacent, and in contact with, the pressure dispersion layer and the adhesive layer, and a flexible connector disposed on the second surface of the backing layer.

The illustrative embodiments described herein are directed to an apparatus, system, and method for storing liquid from a tissue site. The apparatus may include a drape having an aperture, and a fluid pouch coupled to the drape such that the fluid pouch is in fluid communication with the aperture. In one embodiment, the fluid pouch is operable to transfer reduced pressure to the aperture such that the liquid from the tissue site is drawn into the fluid pouch. The fluid pouch may have a cavity that stores the liquid that is drawn from the tissue site. In another embodiment, the fluid pouch may include at least one baffle. The fluid pouch may also include a fluid channel at least partially defined by the at least one baffle. The fluid channel may be operable to store liquid from the tissue site when reduced pressure is applied through the fluid channel.