System and method for negative pressure therapy

Abstract

A system for negative pressure therapy includes a sensing conduit configured to fluidly couple a pressure sensor to a wound dressing and a valve configured to be coupled to the sensing conduit. The system further includes a controller configured to switch the system between a normal mode and a maintenance mode. In the normal mode, the controller is further configured to maintain a therapy pressure at a wound site. In the maintenance mode, the controller is further configured to actuate the valve to connect the sensing conduit with a gas source, thereby passing one or more gases from the gas source to the wound site through the sensing conduit. In the maintenance mode, the controller is further configured to operate a pump at a predetermined pump speed irrespective of a pressure signal received from the pressure sensor while the one or more gases are being passed.

Description

[0001] PA101957W002

[0002] SYSTEM AND METHOD FOR NEGATIVE PRESSURE THERAPY

[0003] Cross-Reference to Related Applications

[0004] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 688,894, filed on August 30, 2024, which is incorporated herein by reference in its entirety.

[0005] Technical Field

[0006] The present disclosure generally relates to a system and a method for negative pressure therapy.

[0007] Background

[0008] Negative pressure wound therapy (NPWT) systems are embodied as sealed wound-care systems particularly indicated for chronic persistent wounds and / or complicated wounds. Specifically, NPWT systems involve application of a pressure that is reduced relative to the surroundings (commonly referred to as “negative pressure”) to the wound for promoting wound healing. Current NPWT systems generally include a therapy unit (including a negative pressure pump) that is in fluid communication with a wound site via a wound dressing applied on the wound site.

[0009] The therapy unit is typically connected to the wound dressing via a single lumen or a multilumen conduit. In the latter case, the multi-lumen conduit may include a primary or central lumen for transporting fluids from the wound site to the therapy unit, and one or more sensing lumens (or peripheral lumens) for communicating wound parameters, such as wound pressure, to a sensing unit. In some cases, the central lumen and the one or more sensing lumens are coupled to one or more solenoids to permit a small but controlled flow of air into these lumens, thereby changing the wound pressure in the wound dressing and increasing a differential pressure between the therapy unit and the wound dressing. This flow may serve to purge any slugs of fluid from the one or more sensing lumens or remove any blockage from the central lumen. Such a process may be repeated periodically during system maintenance to prevent a fluid migration into the one or more sensing lumens, which may result in erroneous pressure feedback.

[0010] Current NPWT systems are electrically designed to prevent the negative pressure pump from being operational while the solenoid connected to the one or more sensing lumens is open during the system maintenance. Thus, system maintenance (periodic opening of the solenoid) applied to the current NPWT systems creates a pump on and off burst mode (for increasing the negative pressure at the wound site), resulting in an undesirable pump ramp noise at every maintenance cycle.

[0011] Summary

[0012] In a first aspect, the present disclosure provides a system for negative pressure therapy of a wound site. The system includes a wound dressing configured to be fluidly coupled to the wound site. The system further includes a negative pressure source including a pump configured to be in fluid communication with the wound dressing and generate a therapy pressure at the wound site. The system further includes a pressure sensor configured to be in fluid communication with the wound dressing and generate a pressure signal indicative of a pressure at the wound site. The system further includes a sensing conduit configured to fluidly couple the pressure sensor to the wound dressing. The system further includes a valve configured to be coupled to the sensing conduit and selectively connect the sensing conduit with a gas source. The system further includes a controller communicably coupled to the negative pressure source, the pressure sensor, the valve, and the gas source. The controller is configured to switch the system between a normal mode and a maintenance mode. In the normal mode, the controller is further configured to maintain the therapy pressure at the wound site based on the pressure signal received from the pressure sensor. In the maintenance mode, the controller is further configured to actuate the valve to connect the sensing conduit with the gas source, thereby passing one or more gases from the gas source to the wound site through the sensing conduit. In the maintenance mode, the controller is further configured to operate the pump at a predetermined pump speed irrespective of the pressure signal received from the pressure sensor while the one or more gases are being passed.

[0013] In a second aspect, the present disclosure provides a method for negative pressure therapy of a wound site. The method includes providing a wound dressing fluidly coupled to the wound site. The method further includes providing a negative pressure source including a pump disposed in fluid communication with the wound dressing. The pump is configured to generate a therapy pressure at the wound site. The method further includes providing a pressure sensor disposed in fluid communication with the wound dressing. The pressure sensor is configured to generate a pressure signal indicative of a pressure at the wound site. The method further includes providing a sensing conduit fluidly coupling the pressure sensor to the wound dressing. The method further includes providing a valve coupled to the sensing conduit. The valve is configured to selectively connect the sensing conduit with a gas source. The method further includes maintaining, via a controller, the therapy pressure at the wound site based on the pressure signal received from the pressure sensor in a normal mode. The method further includes switching, by the controller, from the normal mode to a maintenance mode. The method further includes actuating, by the controller, the valve to connect the sensing conduit with the gas source, thereby passing one or more gases from the gas source to the wound site through the sensing conduit. The method further includes operating, by the controller, the pump at a predetermined pump speed in the maintenance mode irrespective of the pressure signal received from the pressure sensor while the one or more gases are being passed.

[0014] In a third aspect, the present disclosure provides a system for negative pressure therapy of a wound site. The system includes a wound dressing configured to be fluidly coupled to the wound site. The system further includes a positive pressure source including a pump configured to be in fluid communication with the wound dressing and generate a therapy pressure at the wound site. The system further includes a pressure sensor configured to be in fluid communication with the wound dressing and generate a pressure signal indicative of a pressure at the wound site. The system further includes a sensing conduit configured to fluidly couple the pressure sensor to the wound dressing. The system further includes a valve configured to be coupled to the sensing conduit and selectively connect the sensing conduit with an ambient environment. The system further includes a controller communicably coupled to the positive pressure source, the pressure sensor, the valve, and the gas source. The controller is configured to switch the system between a normal mode and a maintenance mode. In the normal mode, the controller is further configured to maintain the therapy pressure at the wound site based on the pressure signal received from the pressure sensor. In the maintenance mode, the controller is further configured to actuate the valve to connect the sensing conduit with the ambient environment, thereby passing one or more gases from the wound site to the ambient environment through the sensing conduit. In the maintenance mode, the controller is further configured to operate the pump at a predetermined pump speed irrespective of the pressure signal received from the pressure sensor while the one or more gases are being passed.

[0015] The details of one or more examples of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the disclosure will be apparent from the description and drawings, and from the claims.

[0016] Brief Description of Drawings

[0017] Exemplary embodiments disclosed herein may be more completely understood in consideration of the following detailed description in connection with the following figures. The figures are not necessarily drawn to scale. Like numbers used in the figures refer to like components. However, it will be understood that the use of a number to refer to a component in a given figure is not intended to limit the component in another figure labeled with the same number.

[0018] FIG. 1 is a schematic block diagram of a system for negative pressure therapy of a wound site, according to an embodiment of the present disclosure;

[0019] FIG. 2 is a schematic block diagram of the system in a maintenance mode, according to an embodiment of the present disclosure;

[0020] FIG. 3 is a schematic block diagram of the system after termination of the maintenance mode, according to an embodiment of the present disclosure;

[0021] FIG. 4 is a schematic block diagram of the system after termination of the maintenance mode, according to another embodiment of the present disclosure;

[0022] FIG. 5 is a schematic block diagram of the system for the negative pressure therapy of the wound site, according to another embodiment of the present disclosure;

[0023] FIG. 6 is a schematic block diagram of the system of FIG. 5 in the maintenance mode, according to an embodiment of the present disclosure; and

[0024] FIG. 7 is a flow chart illustrating a method for a negative pressure therapy of a wound site, according to an embodiment of the present disclosure. Detailed Description

[0025] In the following description, reference is made to the accompanying figures that form a part thereof and in which various embodiments are shown by way of illustration. It is to be understood that other embodiments are contemplated and may be made without departing from the scope or spirit of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense.

[0026] In the following disclosure, the following definitions are adopted.

[0027] As recited herein, all numbers should be considered modified by the term “about”. As used herein, “a,” “an,” “the,” “at least one,” and “one or more” are used interchangeably.

[0028] As used herein as a modifier to a property or attribute, the term “generally”, unless otherwise specifically defined, means that the property or attribute would be readily recognizable by a person of ordinary skill but without requiring absolute precision or a perfect match (e.g., within + / - 20 % for quantifiable properties).

[0029] The term “substantially”, unless otherwise specifically defined, means to a high degree of approximation (e.g., within + / - 10% for quantifiable properties) but again without requiring absolute precision or a perfect match.

[0030] The term “about”, unless otherwise specifically defined, means to a high degree of approximation (e.g., within + / - 5% for quantifiable properties) but again without requiring absolute precision or a perfect match.

[0031] Terms such as same, equal, uniform, constant, strictly, and the like, are understood to be within the usual tolerances or measuring error applicable to the particular circumstance rather than requiring absolute precision or a perfect match.

[0032] As used herein, the terms “first” and “second” are used as identifiers. Therefore, such terms should not be construed as limiting of this disclosure. The terms “first” and “second” when used in conjunction with a feature or an element can be interchanged throughout the embodiments of this disclosure.

[0033] As used herein, “at least one of A and B” should be understood to mean “only A, only B, or both A and B”.

[0034] Unless specified or limited otherwise, the terms “attached,” “connected,” “coupled”, and variations thereof, are used broadly and encompass both direct physical connections, or indirect physical connections between two or more components that are connected together by one or more additional components. For example, a first component may be coupled to a second component by being directly connected together or by being connected by a third component. In some examples, coupling, connection, and attachment may also include mechanical, thermal, electrical, or chemical coupling (such as a chemical bond) in some contexts.

[0035] As used herein, the term “wound” may include, for example, chronic, acute, traumatic, subacute, closed surgical wounds, or dehiscence wounds, partially thick bums, ulcers (such as, diabetic, compressive, or venous insufficiency ulcers), flaps, and grafts. The term may also include an open abdomen area of a patient.

[0036] As used herein, the term “negative pressure” generally refers to a pressure lower than a local ambient pressure in a local environment outside of a sealed treatment environment provided by a dressing at a wound site. In many cases, the local ambient pressure may also be the atmospheric pressure at which the wound site is located. Alternatively, the pressure may be less than a hydrostatic pressure associated with a tissue at the wound site. A reference to an increase in the negative pressure typically refers to a decrease in an absolute pressure, while a decrease in the negative pressure typically refers to an increase in the absolute pressure.

[0037] As used herein, the term “wound site” may include a tissue site, such as, bone tissue, adipose tissue, muscle tissue, nerve tissue, skin tissue, vascular tissue, connective tissue, cartilage, tendons, or ligaments. The term “wound site” may also refer to an area of a tissue that is not necessarily a wound or a defect but may be desired to add or promote additional tissue growth. For example, negative pressure therapy may be used at a particular tissue area to grow additional tissue that may be harvested or transplanted to another tissue site. The wound site may also include an area wherein a surgical incision has been previously performed.

[0038] As used herein, the term “conduit” generally refers to a tube, a pipe, a hose, or other structure with one or more lumina adapted to convey a fluid between two ends. Typically, the conduit is an elongated, cylindrical structure with flexibility, but a geometry and a rigidity may vary.

[0039] Current negative pressure wound therapy (NPWT) systems generally include a therapy unit (including a negative pressure pump) that is in fluid communication with a wound site via a wound dressing applied on the wound site. The therapy unit is typically connected to the wound dressing via a multi-lumen conduit. The multi-lumen conduit may include a primary or central lumen for transporting fluids from the wound site to the therapy unit, and one or more sensing lumens (or peripheral lumens) for communicating wound parameters, such as wound pressure, to a sensing unit. In some cases, the central lumen and the one or more sensing lumens are coupled to one or more solenoids to permit a small but controlled flow of air into these lumens. Such a process may be repeated periodically during system maintenance to prevent a fluid migration into the one or more sensing lumens, which may result in erroneous pressure feedback. Current NPWT systems are electrically designed to prevent the negative pressure pump from being operational while the solenoid connected to the one or more sensing lumens is open during the system maintenance. Thus, system maintenance (periodic opening of the solenoid) applied to the current NPWT systems creates a pump on and off burst mode (for increasing the negative pressure at the wound site), resulting in an undesirable pump ramp noise at every maintenance cycle.

[0040] The present disclosure describes a system for negative pressure therapy of a wound site. The system includes a wound dressing configured to be fluidly coupled to the wound site. The system further includes a negative pressure source including a pump configured to be in fluid communication with the wound dressing and configured to generate a therapy pressure at the wound site. The system further includes a pressure sensor configured to be in fluid communication with the wound dressing and generate a pressure signal indicative of a pressure at the wound site. The system further includes a sensing conduit configured to fluidly couple the pressure sensor to the wound dressing. The system further includes a valve configured to be coupled to the sensing conduit and selectively connect the sensing conduit with a gas source. The system further includes a controller communicably coupled to the negative pressure source, the pressure sensor, the valve, and the gas source. The controller is configured to switch the system between a normal mode and a maintenance mode. In the normal mode, the controller is further configured to maintain the therapy pressure at the wound site based on the pressure signal received from the pressure sensor. In the maintenance mode, the controller is further configured to actuate the valve to connect the sensing conduit with the gas source, thereby passing one or more gases from the gas source to the wound site through the sensing conduit. In the maintenance mode, the controller is further configured to operate the pump at a predetermined pump speed irrespective of the pressure signal received from the pressure sensor while the one or more gases are being passed.

[0041] The system of the present disclosure enables the pump to operate at the predetermined pump speed irrespective of the pressure signal received from the pressure sensor while the one or more gases are being passed during the maintenance mode. This may mitigate a need to ramp up the pump upon termination of the maintenance mode, thereby minimizing sound bursts. Alternatively, a pump ramp after the maintenance mode may be tailored to mitigate pump noises. Additionally, a maintenance cycle of the system may be improved without increasing the associated pump noise. Improvements may include more frequent application of the maintenance mode for purging any slugs of fluid from the sensing conduit. The system may allow the pump to operate independently of the valve as compared to conventional negative pressure therapy systems.

[0042] Referring now to Figures, FIG. 1 illustrates a schematic block diagram of a system 100 for negative pressure therapy of a wound site 102 of a user (not shown). The system 100 may be used for healing the wound site 102 which may be present on the skin of the user. In some examples, the wound site 102 may be a bodily tissue of any human, animal, or other organism. While wound site 102 may include a wound, a diseased tissue, or a defective tissue, the wound site 102 may also include a healthy tissue that is not wounded, diseased, or defective. In some examples, the application of negative pressure therapy to the wound site 102 may be used to promote drainage of wound exudates and other liquids from the wound site 102. In some examples, the system 100 may also be used to provide instillation of topical treatment solutions and debridement to the wound site 102 for therapeutic purposes.

[0043] The system 100 includes a wound dressing 104 configured to be fluidly coupled to the wound site 102. In some examples, the wound dressing 104 covers the wound site 102 and is adapted to seal the wound site 102, thereby creating a therapeutic environment proximal to the wound site 102 for maintaining a negative (or reduced) pressure at the wound site 102. In some examples, the wound dressing 104 may be detachable, and may be disposable, reusable, or recyclable. In some examples, the wound dressing 104 may include a tissue interface, such as, for example, a manifold 110 which may be placed adjacent to or in contact with the wound site 102. The manifold 110 may be a biocompatible, porous material that is capable of distributing the negative pressure to the wound site 102. In some examples, the manifold 110 may be made from a foam, a gauze, a felted mat, or any other material suitable for biological application. In some examples, the manifold 110 may include a plurality of flow channels or pathways to facilitate distribution of the negative pressure or fluids to or from the wound site 102.

[0044] It should be understood that the wound dressing 104 is schematically shown for the purpose of illustration, and the wound dressing 104 may further include other components, such as covers, couplings, etc. In some examples, the cover (not shown) of the wound dressing 104 may provide a bacterial barrier and protection from physical trauma.

[0045] The system 100 further includes a negative pressure source 106 including a pump 108 configured to be in fluid communication with the wound dressing 104 and generate a therapy pressure TP at the wound site 102. In some examples, the therapy pressure TP may be the negative (or reduced) pressure applied to the wound site 102. In some examples, the pump 108 may be driven by an electric motor (not shown). The motor may be a direct-current (DC) motor powered by a DC power supply, such as, for example, a battery (not shown). In some examples, the pump 108 may include a vacuum pump, a suction pump, or a wall suction port, available at many healthcare facilities, or a micro-pump, for example.

[0046] Non-limiting examples of the negative pressure source 106 may include devices that are driven by stored energy, and which are capable of producing the negative pressure (or reduced pressure). Examples may include pumps driven by piezoelectric energy, spring energy, solar energy, kinetic energy, energy stored in capacitors, combustion, and energy developed by Sterling or similar cycles. Other devices or processes that may be used or included in the negative pressure source 106 may include syringes, lead screws, ratchets, clockwork-driven devices, pendulum-driven devices, manual generators, osmotic processes, thermal heating processes, and processes in which vacuum pressures are generated by condensation.

[0047] The system 100 further includes a pressure sensor 112 configured to be in fluid communication with the wound dressing 104 and generate a pressure signal PS indicative of a pressure 116 at the wound site 102. In some examples, the pressure sensor 112 may be a silicon piezo-resistive gauge pressure sensor. However, other suitable pressure sensors may also be utilized. The system 100 further includes a sensing conduit 118 configured to fluidly couple the pressure sensor 112 to the wound dressing 104. The sensing conduit 118 may allow the pressure sensor 112 to detect the pressure 116 at the wound site 102. In some embodiments, the system 100 further includes a suction conduit 126 fluidly coupling the negative pressure source 106 to the wound dressing 104. The sensing conduit 118 is concentric with and overlapping the suction conduit 126. In some examples, the therapy pressure TP generated by the pump 108 may be applied to the wound site 102 through the suction conduit 126. In some examples, the suction conduit 126 may be a primary or central conduit capable of allowing gases, liquids, gels, or other fluids to flow. For example, wound exudates from the wound site 102 may flow through the suction conduit 126.

[0048] In some examples, the system 100 may further include features involving aspirating the wound site 102 together with provision of additional fluids for irrigating and / or cleansing the wound site 102. Thereafter, wound fluids including both wound exudates and the irrigation / cleansing fluids are drawn off by the negative pressure source 106, which may be collected in an exudate container (not shown). In some examples, the therapy pressure TP applied at the wound site 102 may induce macro-strain and micro-strain at the wound site 102, as well as remove the wound fluids from the wound site 102.

[0049] In the illustrated embodiment, the system 100 includes two conduits, i.e., the sensing conduit 118 and the suction conduit 126. However, in some embodiments, the system 100 may further include one or more other conduits for transporting fluids, such as air, antibacterial agents, antiviral agents, cellgrowth promotion agents, irrigation fluids, or other chemically active agents, to the wound site 102. In some examples, the negative pressure source 106 and the wound dressing 104 may be packaged as a single, integrated unit, such as a therapy system including all components shown in FIG. 1 that are fluidly coupled to the wound dressing 104. In some examples, the system 100 may further include other components, such as sensors, processing units, alarm indicators, memories, databases, software, display devices, and / or user interfaces that may further facilitate the negative pressure therapy.

[0050] The system 100 further includes a valve 120 configured to be coupled to the sensing conduit 118 and selectively connect the sensing conduit 118 with a gas source 124. In some examples, the valve 120 may permit an adjustable bleed point for the sensing conduit 118. In other words, the valve 120 may allow a small but controlled flow from the gas source 124 into the sensing conduit 118. This flow serves to purge any slugs of fluid from the sensing conduit 118. In some embodiments, the gas source 124 is an ambient environment. In such a case, air may flow into the sensing conduit 118. Alternatively, in some embodiments, the gas source 124 is an oxygen source. In such a case, pure oxygen or a mixture of oxygen and other gases may flow into the sensing conduit 118.

[0051] The system 100 further includes a controller 122 communicably coupled to the negative pressure source 106, the pressure sensor 112, the valve 120, and the gas source 124. In some examples, the controller 122 may be embodied in a number of different ways. For example, the controller 122 may be embodied as various processing means, such as one or more of a microprocessor, or other processing elements, a coprocessor, or various other computing or processing devices, including integrated circuits, such as, for example, an ASIC (application specific integrated circuit), an FPGA (field programmable gate array), or the like. In some examples, the controller 122 may be configured to execute instructions stored in a memory. In some examples, the memory may be a cache memory, a system memory, or any other memory.

[0052] As such, whether configured by hardware, or by a combination of hardware and software, the controller 122 may represent an entity (e.g., physically embodied in a circuitry in the form of a processing circuitry) capable of performing operations according to some embodiments while configured accordingly. Thus, for example, when the controller 122 is embodied as an ASIC, FPGA, or the like, the controller 122 may have specifically configured hardware for conducting the operations described herein. Alternatively, as another example, when the controller 122 may be embodied as an executor of software instructions, the instructions may specifically configure the controller 122 to perform the operations described herein.

[0053] The controller 122 is configured to switch the system 100 between a normal mode Ml and a maintenance mode M2 (shown in FIG. 2). Specifically, in the normal mode Ml, the controller 122 is further configured to maintain the therapy pressure TP at the wound site 102 based on the pressure signal PS received from the pressure sensor 112. FIG. 2 illustrates the system 100 in the maintenance mode M2.

[0054] Referring to FIG. 2, in the maintenance mode M2, the controller 122 is further configured to actuate the valve 120 to connect the sensing conduit 118 with the gas source 124, thereby passing one or more gases 128 from the gas source 124 to the wound site 102 through the sensing conduit 118. This may change the pressure 116 in the wound dressing 104 and increase a differential pressure between the pump 108 and the wound dressing 104.

[0055] In the maintenance mode M2, the one or more gases 128 entering the sensing conduit 118 remove any blockage within the sensing conduit 118. In other words, the flow of the one or more gases 128 may serve to purge any slugs of fluid from the sensing conduit 118. In case the gas source 124 is the ambient environment, air may flow through the sensing conduit 118. In case the gas source 124 is the oxygen source, oxygen (or a mixture of oxygen and other gases) may flow through the sensing conduit 118.

[0056] In the maintenance mode M2, the controller 122 is further configured to operate the pump 108 at a predetermined pump speed 136 irrespective of the pressure signal PS received from the pressure sensor 112 while the one or more gases 128 are being passed. For example, the controller 122 may operate the pump 108 to continuously apply the therapy pressure TP (shown in FIG. 1) at the wound site 102 irrespective of the pressure signal PS received from the pressure sensor 112. This may mitigate a need to ramp up the pump 108 upon termination of the maintenance mode M2, thereby minimizing sound bursts from the pump 108.

[0057] In some examples, the controller 122 is further configured to periodically switch the system 100 from the normal mode Ml (shown in FIG. 1) to the maintenance mode M2 after a predetermined period of time 138. This may prevent a fluid migration into the sensing conduit 118 that may result in erroneous pressure feedback. In the maintenance mode M2, the one or more gases 128 entering the wound site 102 through the sensing conduit 118 are at least partially sucked by the suction conduit 126. Since the controller 122 operates the pump 108 at the predetermined pump speed 136, the one or more gases 128 entering the wound site 102 through the sensing conduit 118 are at least partially sucked by the suction conduit 126 as shown in FIG. 2. In the maintenance mode M2, the one or more gases 128 at least partially sucked by the suction conduit 126 remove any blockage within the suction conduit 126. Thus, in the maintenance mode M2, the one or more gases 128 from the gas source 124 may purge any slugs of fluid from the sensing conduit 118 as well as remove any blockage from the suction conduit 126.

[0058] In some embodiments, the controller 122 is further configured to terminate the maintenance mode M2 after a predetermined maintenance period of time 134 or a volume of the one or more gases 132. In some examples, the predetermined maintenance period of time 134 may be fixed or may vary based on application requirements. For example, the controller 122 may terminate the maintenance mode M2 after, for example, 5 minutes, or 10 minutes, or the like. In some examples, the volume of the one or more gases 132 may be measured by one or more flow sensors associated with the valve 120 or the gas source 124. In some embodiments, the controller 122 is further configured to actuate the valve 120 to disconnect the sensing conduit 118 from the gas source 124 upon termination of the maintenance mode M2.

[0059] FIG. 3 illustrates a schematic block diagram of the system 100 after termination of the maintenance mode M2 (shown in FIG. 2). In some embodiments, upon termination of the maintenance mode M2, the controller 122 is further configured to determine the pressure 116 at the wound site 102 after a threshold period of time 142 or an indicator of stability 143. The threshold period of time 142 may be fixed (e.g., 5 minutes) or variable based on application requirements. The threshold period of time 142 or the indicator of stability 143 may indicate that the pressure 116 at the wound site 102 has stabilized after termination of the maintenance mode M2.

[0060] In some embodiments, upon termination of the maintenance mode M2, the controller 122 is further configured to determine if the pressure 116 at the wound site 102 is below the therapy pressure TP by a predetermined first threshold 146. The predetermined first threshold 146 may be fixed or variable based on application requirements. In some embodiments, the controller 122 is further configured to determine a required pump speed or a required pump power 144 required by the pump 108 to increase the pressure 116 at the wound site 102 to the therapy pressure TP based on the pressure 116 at the wound site 102 and the predetermined pump speed 136 of the pump 108 in the maintenance mode M2 if the pressure 116 at the wound site 102 is below the therapy pressure TP by the predetermined first threshold 146.

[0061] In some embodiments, the controller 122 is further configured to gradually increase or decrease a pump speed or pump power 140 of the pump 108 at a predetermined rate 148 to achieve the respective required pump speed or the required pump power 144. This may allow the pressure 116 at the wound site 102 to be increased or decreased if the pressure 116 has changed significantly with respect to the therapy pressure TP. In some examples, the predetermined rate 148 may be gradual, thereby allowing a tailored pump ramp and minimizing the sound bursts.

[0062] Alternatively, in some embodiments, upon termination of the maintenance mode M2, the controller 122 is further configured to operate the pump 108 at the predetermined pump speed 136 if the pressure 116 at the wound site 102 is not below the therapy pressure TP by the predetermined first threshold 146.

[0063] FIG. 4 illustrates a schematic block diagram of the system 100 after termination of the maintenance mode M2 (shown in FIG. 2), according to another embodiment of the present disclosure. In the illustrated embodiment, the system 100 further includes a flow rate sensor 156 configured to be in fluid communication with the sensing conduit 118. In some embodiments, the flow rate sensor 156 is configured to generate a flow rate signal 154 indicative of a fluid flow through the sensing conduit 118. The controller 122 is communicably coupled to the flow rate sensor 156.

[0064] In some embodiments, the controller 122 is further configured to determine a leakage flow 150 through the sensing conduit 118 in the maintenance mode M2 (shown in FIG. 2) based on the flow rate signal 154 received from the flow rate sensor 156. The controller 122 is further configured to determine if the leakage flow 150 is above a predetermined second threshold 152.

[0065] In some embodiments, the controller 122 is further configured to determine the required pump speed or the required pump power 144 required by the pump 108 to increase the pressure 116 at the wound site 102 to the therapy pressure TP based on the leakage flow 150 and the predetermined pump speed 136 of the pump 108 in the maintenance mode M2 if the leakage flow 150 is above the predetermined second threshold 152. The predetermined second threshold 152 may be fixed or variable based on application requirements.

[0066] In some embodiments, the controller 122 is further configured to gradually increase or decrease the pump speed or pump power 140 of the pump 108 at a predetermined rate 158 to achieve the respective required pump speed / power 144. This may allow the pressure 116 at the wound site 102 to be increased or decreased if the pressure 116 has changed significantly with respect to the therapy pressure TP. In some examples, the predetermined rate 158 may be gradual, thereby allowing a tailored pump ramp and minimizing the sound bursts.

[0067] Alternatively, in some embodiments, the controller 122 is further configured to operate the pump 108 at the predetermined pump speed 136 if the leakage flow 150 is below the predetermined second threshold 152.

[0068] FIG. 5 illustrates a schematic block diagram of a system 200 for negative pressure therapy of a wound site 202, according to another embodiment of the present disclosure. The system 200 is similar to the system 100 of FIGS. 1-4, and similar or equivalent reference numerals are used to represent same or similar elements.

[0069] The system 200 includes a wound dressing 204 configured to be fluidly coupled to the wound site 202. The system 200 further includes a positive pressure source 206 including a pump 208 configured to be in fluid communication with the wound dressing 204 and generate a therapy pressure TP1 at the wound site 202. In some examples, the pump 208 may deliver a gas (e.g., oxygen) or a mixture of gases at a positive pressure to the wound site 202.

[0070] The system 200 further includes a pressure sensor 212 configured to be in fluid communication with the wound dressing 204 and generate a pressure signal PSI indicative of a pressure 216 at the wound site 202. The system 200 further includes a sensing conduit 218 configured to fluidly couple the pressure sensor 212 to the wound dressing 204. The system 200 further includes a valve 220 configured to be coupled to the sensing conduit 218 and selectively connect the sensing conduit 218 with an ambient environment 224. The system 200 further includes a suction conduit 226 fluidly coupling the positive pressure source 206 to the wound dressing 204.

[0071] The system 200 further includes a controller 222 communicably coupled to the positive pressure source 206, the pressure sensor 212, and the valve 220. The controller 222 is configured to switch the system 200 between a normal mode M3 and a maintenance mode M4 (shown in FIG. 6). Specifically, in the normal mode M3, the controller 222 is further configured to maintain the therapy pressure TP1 at the wound site 202 based on the pressure signal PSI received from the pressure sensor 212.

[0072] FIG. 6 illustrates the system 200 in the maintenance mode M4. Referring to FIG. 4, in the maintenance mode M4, the controller 222 is further configured to actuate the valve 220 to connect the sensing conduit 218 with the ambient environment 224, thereby passing one or more gases 228 from the wound site 202 to the ambient environment 224 through the sensing conduit 218. Since the wound site 202 is at a higher pressure than the ambient environment 224 due to operation of the pump 208, the one or more gases 228 supplied by the pump 208 may flow from the wound site 202 to the ambient environment 224. In the maintenance mode M4, the controller 222 is further configured to operate the pump 208 at a predetermined pump speed 236 irrespective of the pressure signal PSI received from the pressure sensor 212 while the one or more gases 128 are being passed.

[0073] FIG. 7 is a flow chart illustrating a method 300 for negative pressure therapy of a wound site (e.g., the wound site 102 shown in FIGS. 1-4). The method 300 will be described with reference to the system 100 of FIGS. 1-4.

[0074] Referring to FIGS. 1-4 and 7, at step 302, the method 300 includes providing the wound dressing 104 fluidly coupled to the wound site 102.

[0075] At step 304, the method 300 further includes providing the negative pressure source 106 including the pump 108 disposed in fluid communication with the wound dressing 104. The pump 108 is configured to generate the therapy pressure TP at the wound site 102.

[0076] At step 306, the method 300 further includes providing the pressure sensor 112 disposed in fluid communication with the wound dressing 104. The pressure sensor 112 is configured to generate the pressure signal PS indicative of the pressure 116 at the wound site 102. At step 308, the method 300 further includes providing the sensing conduit 118 fluidly coupling the pressure sensor 112 to the wound dressing 104.

[0077] At step 310, the method 300 further includes providing the valve 120 coupled to the sensing conduit 118. The valve 120 is configured to selectively connect the sensing conduit 118 with the gas source 124. In some embodiments, the gas source 124 is an ambient environment. In some embodiments, the gas source 124 is an oxygen source.

[0078] At step 312, the method 300 further includes maintaining, by the controller 122, the therapy pressure TP at the wound site 102 based on the pressure signal PS received from the pressure sensor 112 in the normal mode Ml.

[0079] At step 314, the method 300 further includes switching, by the controller 122, from the normal mode Ml to the maintenance mode M2.

[0080] At step 316, the method 300 further includes actuating, by the controller 122, the valve 120 to connect the sensing conduit 118 with the gas source 124, thereby passing the one or more gases 128 from the gas source 124 to the wound site 102 through the sensing conduit 118.

[0081] At step 318, the method 300 further includes operating, by the controller 122, the pump 108 at the predetermined pump speed 136 in the maintenance mode M2 irrespective of the pressure signal PS received from the pressure sensor 112, while the one or more gases 128 are being passed. In some embodiments, the method 300 further includes removing any blockage within the sensing conduit 118 by the one or more gases 128 entering the sensing conduit 118 in the maintenance mode M2. In some embodiments, the method 300 further includes periodically switching from the normal mode Ml to the maintenance mode M2 after the predetermined period of time 138.

[0082] In some embodiments, the method 300 further includes providing the suction conduit 126 fluidly coupling the negative pressure source 106 to the wound dressing 104. The sensing conduit 118 is concentric with and overlapping the suction conduit 126. In some embodiments, the method 300 further includes at least partially sucking, by the suction conduit 126, the one or more gases 128 entering the wound site 102 through the sensing conduit 118 in the maintenance mode M2. In some embodiments, the method 300 further includes removing any blockage within the suction conduit 126 by the one or more gases 128 at least partially sucked by the suction conduit 126 in the maintenance mode M2.

[0083] In some embodiments, the method 300 further includes terminating, by the controller 122, the maintenance mode M2 after the predetermined maintenance period of time 134 or the volume of the one or more gases 132. In some embodiments, the method 300 further includes actuating, by the controller 122, the valve 120 to disconnect the sensing conduit 118 from the gas source 124 upon termination of the maintenance mode M2.

[0084] In some embodiments, upon termination of the maintenance mode M2, the method 300 further includes determining the pressure 116 at the wound site 102 after the threshold period of time 142 or the indicator of stability 143. In some embodiments, the method 300 further includes determining if the pressure 116 at the wound site 102 is below the therapy pressure TP by the predetermined first threshold 146. In some embodiments, the method 300 further includes determining the required pump speed or the required pump power 144 required by the pump 108 to increase the pressure 116 at the wound site 102 to the therapy pressure TP based on the pressure 116 at the wound site 102 and the predetermined pump speed 136 of the pump 108 in the maintenance mode M2 if the pressure 116 at the wound site 102 is below the therapy pressure TP by the predetermined first threshold 146. In some embodiments, the method 300 further includes gradually increasing or decreasing, by the controller 122, the pump speed or pump power 140 at the predetermined rate 148 to achieve the respective required pump speed or the required pump power 144.

[0085] In some embodiments, the method 300 further includes operating, by the controller 122, the pump 108 at the predetermined pump speed 136 if the pressure 116 at the wound site 102 is not below the therapy pressure TP by the predetermined first threshold 146.

[0086] Referring to FIGS. 1-7, the system 100, 200 and the method 300 of the present disclosure enables the pump 108, 208 to operate at the predetermined pump speed 136, 236 irrespective of the pressure signal PS, PSI received from the pressure sensor 112, 212 while the one or more gases 128, 228 are being passed during the maintenance mode M2, M4. This may mitigate a need to ramp up the pump 108, 208 upon termination of the maintenance mode M2, M4, thereby minimizing sound bursts. Alternatively, a pump ramp after the maintenance mode M2, M4 may be tailored to mitigate pump noises. Additionally, a maintenance cycle of the system 100, 200 may be improved without increasing the associated pump noise. Improvements may include more frequent application of the maintenance mode M2, M4 for purging any slugs of fluid from the sensing conduit 118, 218. The system 100, 200 and the method 300 may allow the pump 108, 208 to operate independently of the valve 120, 220 as compared to conventional negative pressure therapy systems.

[0087] In the present detailed description of the preferred embodiments, reference is made to the accompanying drawings, which illustrate specific embodiments in which the invention may be practiced. The illustrated embodiments are not intended to be exhaustive of all embodiments according to the invention. It is to be understood that other embodiments may be utilized, and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.

[0088] Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” encompass embodiments having plural referents, unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and / or” unless the content clearly dictates otherwise.

[0089] Various examples have been described. These and other examples are within the scope of the following claims.

Claims

CLAIMS:

1. A system for negative pressure therapy of a wound site, the system comprising: a wound dressing configured to be fluidly coupled to the wound site; a negative pressure source comprising a pump configured to be in fluid communication with the wound dressing and generate a therapy pressure at the wound site; a pressure sensor configured to be in fluid communication with the wound dressing and generate a pressure signal indicative of a pressure at the wound site; a sensing conduit configured to fluidly couple the pressure sensor to the wound dressing; a valve configured to be coupled to the sensing conduit and selectively connect the sensing conduit with a gas source; and a controller communicably coupled to the negative pressure source, the pressure sensor, the valve, and the gas source, wherein the controller is configured to switch the system between a normal mode and a maintenance mode, wherein, in the normal mode, the controller is further configured to maintain the therapy pressure at the wound site based on the pressure signal received from the pressure sensor, and wherein, in the maintenance mode, the controller is further configured to: actuate the valve to connect the sensing conduit with the gas source, thereby passing one or more gases from the gas source to the wound site through the sensing conduit; and operate the pump at a predetermined pump speed irrespective of the pressure signal received from the pressure sensor while the one or more gases are being passed.

2. The system of claim 1, wherein the gas source is an ambient environment.

3. The system of claim 1, wherein the gas source is an oxygen source.

4. The system of claim 1, wherein the controller is further configured to: terminate the maintenance mode after a predetermined maintenance period of time or a volume of the one or more gases; and actuate the valve to disconnect the sensing conduit from the gas source upon termination of the maintenance mode.

5. The system of claim 4, wherein, upon termination of the maintenance mode, the controller is further configured to: determine the pressure at the wound site after a threshold period of time or an indicator of stability; determine if the pressure at the wound site is below the therapy pressure by a predetermined first threshold; determine a required pump speed or a required pump power required by the pump to increase the pressure at the wound site to the therapy pressure based on the pressure at thewound site and the predetermined pump speed of the pump in the maintenance mode if the pressure at the wound site is below the therapy pressure by the predetermined first threshold; and gradually increase or decrease pump speed or pump power at a predetermined rate to achieve the respective required pump speed or the required pump power.

6. The system of claim 5, wherein the controller is further configured to operate the pump at the predetermined pump speed if the pressure at the wound site is not below the therapy pressure by the predetermined first threshold.

7. The system of claim 1, further comprising a suction conduit fluidly coupling the negative pressure source to the wound dressing, wherein the sensing conduit is concentric with and overlapping the suction conduit, such that, in the maintenance mode, the one or more gases entering the wound site through the sensing conduit are at least partially sucked by the suction conduit.

8. The system of claim 7, wherein, in the maintenance mode, the one or more gases at least partially sucked by the suction conduit remove any blockage within the suction conduit.

9. The system of claim 1, wherein, in the maintenance mode, the one or more gases entering the sensing conduit remove any blockage within the sensing conduit.

10. The system of claim 1, wherein the controller is further configured to periodically switch the system from the normal mode to the maintenance mode after a predetermined period of time.

11. A method for negative pressure therapy of a wound site, the method comprising: providing a wound dressing fluidly coupled to the wound site; providing a negative pressure source comprising a pump disposed in fluid communication with the wound dressing, wherein the pump is configured to generate a therapy pressure at the wound site; providing a pressure sensor disposed in fluid communication with the wound dressing, wherein the pressure sensor is configured to generate a pressure signal indicative of a pressure at the wound site; providing a sensing conduit fluidly coupling the pressure sensor to the wound dressing; providing a valve coupled to the sensing conduit, wherein the valve is configured to selectively connect the sensing conduit with a gas source; maintaining, by a controller, the therapy pressure at the wound site based on the pressure signal received from the pressure sensor in a normal mode; switching, by the controller, from the normal mode to a maintenance mode; actuating, by the controller, the valve to connect the sensing conduit with the gas source, thereby passing one or more gases from the gas source to the wound site through the sensing conduit; andoperating, by the controller, the pump at a predetermined pump speed in the maintenance mode irrespective of the pressure signal received from the pressure sensor while the one or more gases are being passed.

12. The method of claim 11, wherein the gas source is an ambient environment.

13. The method of claim 11, wherein the gas source is an oxygen source.

14. The method of claim 11, further comprising: terminating, by the controller, the maintenance mode after a predetermined maintenance period of time or a volume of the one or more gases; and actuating, by the controller, the valve to disconnect the sensing conduit from the gas source upon termination of the maintenance mode.

15. The method of claim 14, wherein, upon termination of the maintenance mode, the method further comprises: determining the pressure at the wound site after a threshold period of time or an indicator of stability; determining if the pressure at the wound site is below the therapy pressure by a predetermined first threshold; determining a required pump speed or a required pump power required by the pump to increase the pressure at the wound site to the therapy pressure based on the pressure at the wound site and the predetermined pump speed of the pump in the maintenance mode if the pressure at the wound site is below the therapy pressure by the predetermined first threshold; and gradually increasing or decreasing, by the controller, pump speed or pump power at a predetermined rate to achieve the respective required pump speed or the required pump power.

16. The method of claim 15, further comprising operating, by the controller, the pump at the predetermined pump speed if the pressure at the wound site is not below the therapy pressure by the predetermined first threshold.

17. The method of claim 11, further comprising: providing a suction conduit fluidly coupling the negative pressure source to the wound dressing, wherein the sensing conduit is concentric with and overlapping the suction conduit; and at least partially sucking, by the suction conduit, the one or more gases entering the wound site through the sensing conduit in the maintenance mode.

18. The method of claim 17, further comprising removing any blockage within the suction conduit by the one or more gases at least partially sucked by the suction conduit in the maintenance mode.

19. The method of claim 11, further comprising removing any blockage within the sensing conduit by the one or more gases entering the sensing conduit in the maintenance mode.

20. The method of claim 11, further comprising periodically switching from the normal mode to the maintenance mode after a predetermined period of time.

21. A system for negative pressure therapy of a wound site, the system comprising: a wound dressing configured to be fluidly coupled to the wound site; a positive pressure source comprising a pump configured to be in fluid communication with the wound dressing and generate a therapy pressure at the wound site; a pressure sensor configured to be in fluid communication with the wound dressing and generate a pressure signal indicative of a pressure at the wound site; a sensing conduit configured to fluidly couple the pressure sensor to the wound dressing; a valve configured to be coupled to the sensing conduit and selectively connect the sensing conduit with an ambient environment; and a controller communicably coupled to the positive pressure source, the pressure sensor, and the valve, wherein the controller is configured to switch the system between a normal mode and a maintenance mode, wherein, in the normal mode, the controller is further configured to maintain the therapy pressure at the wound site based on the pressure signal received from the pressure sensor, and wherein, in the maintenance mode, the controller is further configured to: actuate the valve to connect the sensing conduit with the ambient environment, thereby passing one or more gases from the wound site to the ambient environment through the sensing conduit; and operate the pump at a predetermined pump speed irrespective of the pressure signal received from the pressure sensor while the one or more gases are being passed.

Images