A negative pressure wound therapy system can include a wound dressing configured to be placed over a wound and configured to absorb fluid. The system can include a source of negative pressure configured to generate negative pressure to aspirate fluid from the wound. The system can include a memory. The system can include a controller configured to periodically store a plurality of data sets in the memory, in response to storing a data set of the plurality of data sets at a memory address in the memory, update the memory address for storing a subsequent data set, and in response to determining that the memory address corresponds to a memory address indicative of a duration of time following an initial activation of the system reaching a total permitted operational time of the system, provide an indication that the total permitted operational time of the system has been reached.

A dressing for treating tissue with negative pressure is provided herein comprising a composite of dressing layers, including a release film, a perforated coated polymer film, a manifold, and an adhesive cover. Additionally, a method of manufacturing the dressing may comprise applying a cross-linkable polymer to a polymer film, curing the cross-linkable polymer to a gel layer to form a coated polymer film, and perforating the coated polymer film to form fluid restrictions, such as slits and/or slots, though the coated polymer film.

An appliance is provided for negative-pressure therapy of wounds on the human or animal body in which, on the one hand, a substance is delivered to a wound bed (W) and, on the other hand, fluids, in particular an exudate and the delivered substance, are aspirated from the wound bed by negative pressure. The appliance has a suction pump housing, with a suction pump arranged therein for aspirating the fluids from the wound bed (W), and a fluid collection container for collecting the aspirated fluids. Moreover, the appliance has a first measuring device and a second measuring device. The first measuring device serves to determine the quantity of the aspirated fluids, and the second measuring device serves to determine the quantity of the substance delivered to the body.

A manually-actuated, constant reduced-pressure apparatus for use with a reduced-pressure system for treating tissue at a tissue site includes a flexible, collapsible member that is operable to move between a compressed position and an extended position. The collapsible member may be disposed between a carrier member and a slider member that move between a compressed position and an extended position. The carrier member and slider member are urged away from each other by a constant-force biasing member, e.g., a constant force coil spring. As the apparatus moves from the compressed position to the extended position, a constant reduced-pressure is generated and delivered to a reduced-pressure port. Methods of manufacturing a manually-actuated, constant reduced-pressure apparatus and methods of treating a tissue site are also provided.

Pump cassettes, wound-treatment apparatuses and methods. In some embodiments, a pump cassette comprises: a pump body having a pump chamber, an inlet valve in fluid communication with the pump chamber, and an outlet valve in fluid communication with the pump chamber; a diaphragm coupled to the pump body such that the diaphragm is movable to vary a volume in the pump chamber; and an identifier configured to store one or more properties of the pump cassette such that the identifier is readable by an automated reader to determine the one or more properties. In some embodiments, the pump cassette is configured to be removably coupled to a wound-treatment apparatus having an actuator such that the actuator can be activated to move the diaphragm.

Embodiments of a negative pressure wound therapy systems and methods for operating the systems are disclosed. In some embodiments, a system includes a pump assembly, canister, and a wound dressing configured to be positioned over a wound. The pump assembly, canister, and the wound dressing can be fluidically connected to facilitate delivery of negative pressure to a wound. The system can be configured to efficiently deliver negative pressure in continuous and intermittent modes. The system can also be configured to gradually ramp up and down to set pressure values. The system can also be configured to detect and indicate presence of certain conditions, such as low pressure, high pressure, leak, canister full, and the like. Detection and indication of the presence of at least some of these conditions can be enabled and disabled.

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.

According to certain embodiments, an apparatus for applying negative pressure to a wound can include a negative pressure source, a sensor, and a controller. The negative pressure source can be configured to couple via a fluid flow path to a wound dressing and provide negative pressure to the wound dressing. The sensor can be configured to monitor a magnitude or frequency of pressure in the fluid flow path generated by the negative pressure source. The controller can be configured to determine an activity classification, such as breathing, changing positions while lying, sitting, walking, standing, jumping, traversing stairs, leg extending, leg bending, and performing chair squats, based on a change in the magnitude of pressure over time while the negative pressure source maintains the magnitude of pressure in the fluid flow path below a negative pressure threshold. The controller can output an indication of the activity classification.

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.

The wound therapy apparatus may include a wound interface sealingly securable to the skin surface around a wound bed to encloses the wound bed within an enclosed space that is fluid-tight. The wound interface may be sufficiently deformation resistant to distend at least a portion of the wound bed into the enclosed space when pressure p.sub.0 within the enclosed space is less than ambient pressure p.sub.amb. Fluid may be communicated with the enclosed space when the wound interface is sealingly secured to the skin surface in order to vary a pressure p.sub.0 within the enclosed space periodically over the pressure range p.sub.min≤p.sub.0≤p.sub.max. The variation of the pressure p.sub.0 may distend the wound bed into communication with a pad received within the enclosed space and decreases the wound bed contact with the pad. Related methods of use of the wound therapy apparatus are also disclosed.