Negative pressure therapy systems and devices

Abstract

Disclosed embodiments relate to apparatuses and methods for applying negative pressure to a tissue site or skin site to prepare for a surgical operation. The apparatuses and methods can be used to increase blood flow at or near the tissue site. Therapeutic gas can also be applied to prepare the tissue site for the operation. Antimicrobial and antiseptic agents can also be applied to reduce the bioburden at the tissue site.

Description

[0001] NEGATIVE PRESSURE THERAPY SYSTEMS, DEVICES, AND METHODS

[0002] CROSS REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to Great Britain Provisional Application No. 2414412.3, filed October 1, 2024, and titled NEGATIVE PRESSURE THERAPY SYSTEMS, DEVICES, AND METHODS. The aforementioned application is incorporated by reference herein in its entirety.

[0004] FIELD

[0005] Embodiments of the present disclosure relate to apparatuses, systems, and methods for the treatment of tissues via negative pressure therapy regimes. Embodiments described herein relate to a negative pressure therapy device, apparatus, and method of increasing blood perfusion to prepare a tissue site for a surgical procedure.

[0006] BACKGROUND

[0007] Post-operative surgical site complications can occur in patients when an unhealthy tissue is incised or operated upon. Such complications can cause severe harm to patients and lead to a variety of health problems. A measure of tissue health is the blood perfusion in the tissue of interest and surrounding tissues. Improving blood perfusion before a surgical procedure can reduce the risk of post-operative surgical site complications. Another contributing factor to the development of these complications is the patient’s routine prior to the surgical intervention. Notably, patients can be instructed to keep the area of the tissue clean prior to surgery and are provided with various products or regimes to satisfy this. However, patients may not comply with the skin preparation necessary to reduce the risk of complications.

[0008] Therefore, there is a need for improved tissue site preparation, particularly for increasing blood perfusion in the tissue site and surrounding tissues. One factor that is known to be correlated with blood perfusion is the Skin Perfusion Pressure (SPP) in tissue. SPP is the amount of pressure required to restore blood flow to blood vessels within skin tissue following a controlled occlusion of the blood vessels using a blood pressure cuff. Pre-operative preparation can include negative pressure therapy (which may increase tissue perfusion) and tissue cleaning. Such techniques are typically performed sporadically with varying amounts of patient compliance. Additionally, a wound dressing is typically applied to a wound in order to protect the wound from pathogens, assist healing of the wound and to protect the area of the wound from further injury. In order to assess healing, the tissue in and around the wound may be inspected periodically. Inspection can be carried out by a clinician using the naked eye, but may also be carried out using optical devices that analyze the appearance of the wounded area to determine the state of the wound. To access the wounded area, the wound dressing must be removed. This is time consuming, inconvenient and often uncomfortable for the patient. Moreover, the original dressing is usually replaced by a fresh dressing even though the old dressing may not have needed replacing at the time of inspection.

[0009] SUMMARY

[0010] It is an aim of the embodiments described herein to at least partly mitigate the above- mentioned problems.

[0011] In some examples, the methods described herein can relate to preparing a tissue site for a surgical procedure, the method including: positioning a tissue conditioning device over a skin site identified for surgical incision, the tissue conditioning device including: a top film; a skin contact layer; and a compression-resistant spacer material between the top film and the skin contact layer; and applying negative pressure through the tissue conditioning device to the skin site to increase blood perfusion below the skin site prior to surgical incision of the skin site.

[0012] In some examples, the tissue conditioning device is wearable. In some examples, applying negative pressure includes applying negative pressure constantly for a period of at least 1 day and less than 7 days. In some examples, applying negative pressure includes applying negative pressure constantly for a period of between at least 3 days and less than 5 days. In some examples, the tissue conditioning device further includes a pressure sensitive adhesive on a distal side of the top film. In some examples, the method can include delivering an antiseptic agent or an antimicrobial agent to the skin site using the tissue conditioning device. In some examples, the method can include determining a quality of the skin site by viewing the skin site while the tissue conditioning device is positioned over the skin site, wherein the tissue conditioning device is translucent. In some examples, the compressionresistant spacer material of the tissue conditioning device includes fenestrations sized for increasing visibility of the skin site. In some examples, the method can include delivering a therapeutic conditioning gas to the skin site through the tissue conditioning device. In some examples, the method can include simultaneously delivering the therapeutic conditioning gas and the negative pressure. In some examples, the method can include delivering nitric oxide to the skin site through the tissue conditioning device. In some examples, the method can include measuring at least one of amount of volatile organic compounds, blood oxygen, or tissue stiffness using a sensor on the tissue conditioning device. In some examples, the method can include determining whether a tissue is ready for an incisional procedure based on at least one of the amount of volatile organic compounds, blood oxygen, or tissue stiffness.

[0013] In some examples, the systems described herein can relate to providing negative pressure in preparation for a surgical procedure. The system can include: a tissue conditioning device configured to be positioned over a skin site identified for surgical incision, the tissue conditioning device including: a top film; a skin contact layer; and a compression-resistant spacer material between the top film and the skin contact layer; a conduit, a distal end of the conduit configured to connect to the tissue conditioning device; a valve configured to allow fluid to enter the conduit when the valve is open; a pump configured to evacuate gas from the conduit; and a pressure sensor configured to measure pressure in the conduit.

[0014] In some examples, the system can include a controller configured to receive measurements from the pressure sensor and control at least one of the valve or the pump based on the measurements. In some examples, the system can include a user interface configured to display measurements of the pressure sensor. In some examples, the system can include: a second conduit, a distal end of the second conduit configured to connect to the tissue conditioning device; a second valve configured to allow fluid to enter the second conduit when the second valve is open; and a second pressure sensor configured to measure pressure in the second conduit. In some examples, the system can include a controller configured to receive measurements from the pressure sensor and the second pressure sensor and control at least one of the valve, the second valve, or the pump based on the measurements. In some examples, the system can include a user interface configured to display measurements of at least one of the pressure sensor or the second pressure sensor. In some examples, the tissue conditioning device is wearable. In some examples, the tissue conditioning device further includes a pressure sensitive adhesive on a distal side of the top film. In some examples, the tissue conditioning device is configured to deliver an antiseptic agent or an antimicrobial agent to the skin site. In some examples, the tissue conditioning device is translucent. In some examples, the compression-resistant spacer material of the tissue conditioning device includes fenestrations sized for increasing visibility of the skin site. In some examples, the tissue conditioning device is configured to deliver a therapeutic conditioning gas to the skin site. In some examples, the conduit is configured to deliver negative pressure to the skin site while the second conduit simultaneously delivers a therapeutic conditioning gas to the skin site. In some examples, the tissue conditioning device is configured to deliver nitric oxide to the skin site. In some examples, the system can include measuring a sensor on the tissue conditioning device configured to measure at least one of amount of volatile organic compounds, blood oxygen, or tissue stiffness.

[0015] In some examples, the methods described herein can relate to preparing a tissue site for a surgical procedure, the method including: positioning a tissue conditioning device over a skin site identified for surgical incision, the tissue conditioning device including: a top film; a skin contact layer; and a compression-resistant spacer material between the top film and the skin contact layer; and delivering a gas through the tissue conditioning device to the skin site to reduce a bioburden of the skin site before the surgical incision of the skin site, wherein the gas includes at least one of antibacterial gas, antimicrobial gas, or antiseptic gas.

[0016] In some examples, the tissue conditioning device is wearable. In some examples, the tissue conditioning device further includes a pressure sensitive adhesive on a distal side of the top film. In some examples, the method can include applying negative pressure to the skin site using the tissue conditioning device. In some examples, the method can include determining a quality of the skin site by viewing the skin site while the tissue conditioning device is positioned over the skin site, wherein the tissue conditioning device is translucent. In some examples, the compression-resistant spacer material of the tissue conditioning device includes fenestrations sized for increasing visibility of the skin site. In some examples, the method can include delivering a therapeutic conditioning gas to the skin site through the tissue conditioning device. In some examples, the method can include simultaneously delivering the therapeutic conditioning gas and the gas. In some examples, the method can include delivering nitric oxide to the skin site through the tissue conditioning device. In some examples, the method can include measuring at least one of amount of volatile organic compounds, blood oxygen, or tissue stiffness using a sensor on the tissue conditioning device. In some examples, the method can include determining whether a tissue is ready for an incisional procedure based on at least one of the amount of volatile organic compounds, blood oxygen, or tissue stiffness.

[0017] In some examples, the methods described herein can relate to treating a tissue site after a surgical procedure, the method including: positioning a tissue conditioning device over a surgically incised skin site, the tissue conditioning device including: a top film; a skin contact layer; and a compression-resistant spacer material between the top film and the skin contact layer; and applying negative pressure through the tissue conditioning device to the skin site to increase blood perfusion below the skin site after surgical incision of the skin site. In some examples, the negative pressure is applied from a negative pressure source without a canister.

[0018] BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings in which:

[0020] Figures 1A and IB show an apparatus for applying negative pressure to increase skin perfusion pressure.

[0021] Figures 2A and 2B show other examples of a tissue conditioning device.

[0022] Figure 3 shows the tissue conditioning device of Figure 2A connected to a fluid delivery system.

[0023] Figure 4 shows an example of the tissue conditioning device of Figure 2A connected to another example of a fluid delivery system.

[0024] Figures 5A-5B show other examples of a tissue conditioning device.

[0025] Figures 6A-6D show other examples of a tissue conditioning device.

[0026] DETAILED DESCRIPTION

[0027] Embodiments disclosed herein relate to apparatuses and methods of applying negative pressure therapy before surgical procedures. The embodiments disclosed herein are not limited to treatment or monitoring of a particular type of tissue or surgical procedure, instead the negative therapy technologies disclosed herein are broadly applicable to any type of procedure that may benefit from pre-operative negative pressure therapy.

[0028] Some embodiments disclosed herein relate to the use of negative pressure to prepare a tissue site or skin site for a surgical procedure. The embodiments described herein can be used to increase blood flow at or near the tissue site. Therapeutic gas can also be applied to prepare the tissue site for the operation. Antimicrobial and antiseptic agents can also be applied to reduce the bioburden at the tissue site.

[0029] Negative Pressure Wound Dressing

[0030] In some examples, treatment of such tissue sites can be performed using negative pressure therapy, wherein a reduced or negative pressure can be applied to the tissue to facilitate and promote blood perfusion. It will also be appreciated that the negative pressure dressing and methods as disclosed herein may be applied to the treatment of wounds. It will be understood that embodiments of the present disclosure are generally applicable to use in topical negative pressure ("TNP") therapy systems. Briefly, negative pressure therapy encourage blood flow and granular tissue formation. Negative pressure may also be used to remove excess exudate from wounds and may reduce bacterial load (and thus infection risk).

[0031] Topical negative pressure (TNP) therapy can involve placing a cover that is impermeable or semi-permeable to fluids over the wound, using various means to seal the cover to the tissue of the patient surrounding the wound, and connecting a source of negative pressure (such as a vacuum pump) to the cover in a manner so that negative pressure is created and maintained under the cover. It is believed that such negative pressures assist the body ’ s normal inflammatory process while simultaneously removing adverse cytokines or bacteria.

[0032] Some of the dressings used in TNP can include many different types of materials and layers, for example, gauze, pads, foam pads or multi-layer wound dressings. One example of a multi-layer wound dressing is the PICO dressing, available from Smith & Nephew, includes a contact layer and a superabsorbent layer beneath a backing layer to provide a canister-less system for treating a wound with NPWT. The dressing may be sealed to a suction port providing connection to a length of tubing, which may be used to pump fluid out of the dressing or to transmit negative pressure from a pump to the dressing. Additionally, RENAS YS-F, RENASYS-G, RENASYS-AB, and RENASYS-F / AB, available from Smith & Nephew, are additional examples of NPWT wound dressings and systems. Another example of a multilayer wound dressing is the ALLEVYN Life dressing, available from Smith & Nephew, which includes a moist wound environment dressing that is used to treat the wound without the use of negative pressure.

[0033] As is used herein, reduced or negative pressure levels, such as -X mmHg, represent pressure levels relative to normal ambient atmospheric pressure, which can correspond to 760 mmHg (or 1 atm, 29.93 inHg, 101.325 kPa, 14.696 psi, etc.). Accordingly, a negative pressure value of -X mmHg reflects absolute pressure that is X mmHg below 760 mmHg or, in other words, an absolute pressure of (760-X) mmHg. In addition, negative pressure that is "less" or "smaller" than X mmHg corresponds to pressure that is closer to atmospheric pressure (such as, -40 mmHg is less than -60 mmHg). Negative pressure that is "more" or "greater" than -X mmHg corresponds to pressure that is further from atmospheric pressure (such as, -80 mmHg is more than -60 mmHg). In some embodiments, local ambient atmospheric pressure is used as a reference point, and such local atmospheric pressure may not necessarily be, for example, 760 mmHg. The negative pressure range for some embodiments of the present disclosure can be approximately -80 mmHg, or between about -20 mmHg and -200 mmHg. Note that these pressures are relative to normal ambient atmospheric pressure, which can be 760 mmHg. Thus, -200 mmHg would be about 560 mmHg in practical terms. In some embodiments, the pressure range can be between about -40 mmHg and -150 mmHg. Alternatively a pressure range of up to -75 mmHg, up to -80 mmHg or over -80 mmHg can be used. Also in other embodiments a pressure range of below -75 mmHg can be used. Alternatively, a pressure range of over approximately -100 mmHg, or even -150 mmHg, can be supplied by the negative pressure apparatus.

[0034] In some examples, negative pressure may be varied over time for example using a sinusoidal wave, square wave, or in synchronization with one or more patient physiological indices (such as, heartbeat). Examples of such applications where additional disclosure relating to the preceding may be found include U.S. Patent No. 8,235,955, titled "Wound treatment apparatus and method," issued on August 7, 2012; and U.S. Patent No. 7,753,894, titled "Wound cleansing apparatus with stress," issued July 13, 2010. The disclosures of both of these patents are hereby incorporated by reference in their entirety.

[0035] Embodiments of the dressings, dressing components, treatment apparatuses and methods described herein may also be used in combination or in addition to those described in International Application No. PCT / IB2013 / 001469, filed May 22, 2013, published as WO 2013 / 175306 A2 on November 28, 2013, titled "APPARATUSES AND METHODS FOR NEGATIVE PRESSURE WOUND THERAPY," U.S. Patent Application No. 14 / 418,908, filed January 30, 2015, published as US 2015 / 0190286 Al on July 9, 2015, titled "WOUND DRESSING AND METHOD OF TREATMENT," the disclosures of which are hereby incorporated by reference in their entireties. Embodiments of the wound dressings, wound dressing components, wound treatment apparatuses and methods described herein may also be used in combination or in addition to those described in U.S. Patent Application No. 13 / 092,042, filed April 21, 2011, published as US2011 / 0282309, titled "WOUND DRESSING AND METHOD OF USE," and U.S. Patent Application No. 14 / 715,527, filed May 18, 2015, published as US2016 / 0339158 Al on November 24, 2016, titled “FLUIDIC CONNECTOR FOR NEGATIVE PRESSURE WOUND THERAPY,” the disclosure of each of which is hereby incorporated by reference in its entirety, including further details relating to embodiments of dressings, the wound dressing components and principles, and the materials used for the dressings. Additionally, some embodiments related to TNP treatment comprising a dressing in combination with a pump or associated electronics described herein may also be used in combination or in addition to those described in International Application PCT / EP2016 / 059329 filed April 26, 2016, published as WO 2016 / 174048 on November 3, 2016, entitled “REDUCED PRESSURE APPARATUS AND METHODS,” the disclosure of which is hereby incorporated by reference in its entirety.

[0036] Skin Perfusion Pressure Treatment

[0037] Figures 1A and IB show an apparatus 2 for conditioning tissue prior to a surgical incision. For example, the tissue may be conditioned by applying negative pressure to increase skin perfusion pressure, by treating the tissue with a transdermal active, by delivering antibacterial gas, or via other suitable techniques.

[0038] In some examples, the apparatus 2 can include a tissue conditioning device 4. The tissue conditioning device 4 can be a dressing, for example a topical dressing. The tissue conditioning device 4 can be enhanced or optimized for use before surgical operations, for example with improved wearability. The tissue conditioning device 4 can be wearable such that negative pressure can be applied to a tissue site of a patient for an extended period of time. Negative pressure therapy can remove excess exudate from the tissue, maintain moisture balance, increase blood flow to an near the tissue, control infection, and modulate immune responses.

[0039] In some examples, the tissue conditioning device 4 can include a top film 6. The top film 6 can include a border space 8 and a treatment space 10. The treatment space 10 can be surrounded by the border space 8, such that the treatment space 10 is at the center of the top film 6. The top film 6 can be moisture vapor permeable. In some examples, the border space 8 can be moisture vapor permeable. The treatment space 10 can be gas impermeable. The top film 6 can be made of polyurethane (PU) with high moisture vapor permeability. In another example, the top film 6 can be made of ePTFE, thermoplastic polyurethane, silicone, polypropylene, polyethylene, polyesters, copolymers, and / or natural fiber blends. The border space 8 can be covered with a release handle or carrier layer. The release handle or carrier layer can protect the tissue contacting adhesive.

[0040] In some examples, the tissue conditioning device 4 can include a contact layer 12. The contact layer 12 can contact the tissue, for example the skin, of the patient. The contact layer 12 can be attached to the top film 6 at the periphery of the layers. The contact layer 12 can be coated with adhesive. In some examples, the adhesive can be based on silicone, polyurethane, hot-melts, acrylics, another adhesive material, or a combination of these adhesives. The contact layer 12 can be made of PU. In another example, the contact layer 12 can be made of ePTFE, thermoplastic polyurethane, silicone, polypropylene, and / or natural fiber blends. Advantageously, the dressing for pre-operative care may not strictly need to be sterile, because the dressing may be applied to intact skin.

[0041] In some examples, the tissue conditioning device 4 can include spacer material 14 between the top film 6 and the contact layer 12. The spacer material 14 can be compressionresistant. The spacer material 14 can resist compression while negative pressure is being applied to the tissue conditioning device 4. The spacer material 14 can resist compression in the plane perpendicular to the top film 6 and contact layer 12. The spacer material 14 can allow for flexibility outside of the plane perpendicular to the top film 6 and contact layer 12. The spacer material 14 can allow airflow in the plane parallel to the top film 6 and contact layer 12. The spacer material 14 can act as an air-void that enables the effective distribution of the vacuum over the pad area.

[0042] In some examples, the apparatus 2 can include an adapter 16 for delivering negative pressure to the tissue conditioning device 4. The adapter 16 can be connected by a conduit 18 to a negative pressure source. The negative pressure source can be a vacuum source or an electronic vacuum pump. The adapter 16 can connect to the treatment space 10 of the top film 6 of the tissue conditioning device 4.

[0043] In some examples, a user can apply negative pressure to a skin site of a patient to improve blood perfusion in the tissue and in surrounding tissue. Before a surgical operation, it can be advantageous to apply negative pressure to the tissue site proximate to the site of the operation. In some examples, negative pressure can be applied to the tissue site for a period of greater than about 3 days and / or less than about 5 days. Negative pressure can be applied to the tissue site for a period of greater than about 1 day and / or less than about 7 days. Negative pressure can be applied to the tissue site for a period of greater than about 12 hours and / or less than about 10 days. Negative pressure can be applied to the tissue site for a period of greater than about 1 hour and / or less than about 20 days. Negative pressure can be applied constantly during the time period. Negative pressure can be applied intermittently during the time period.

[0044] In some examples, the apparatus 2 can increase blood perfusion or blood flow at or near the tissue site by 30%. The apparatus 2 can increase blood perfusion or blood flow at or near the tissue site by at least 20% and / or less than or equal to 40%. The apparatus 2 can increase blood perfusion or blood flow at or near the tissue site by at least 10% and / or less than or equal to 60%. The apparatus 2 can increase blood perfusion or blood flow at or near the tissue site by at least 5% and / or less than or equal to 80%. The apparatus 2 can increase blood perfusion or blood flow at or near the tissue site by at least 2% and / or less than or equal to 95%. The apparatus 2 can increase blood perfusion or blood flow at or near the tissue site by at least 1% and / or less than or equal to 99%. In certain examples, the apparatus may increase blood perfusion or blood flow by a factor of two, three, four, five or more than five times. In some examples, the apparatus 2 may increase blood flow or perfusion to tissue that may currently have limited or no blood perfusion.

[0045] In some examples, the tissue conditioning device 4 can deliver an agent to the tissue site. The contact layer 12 can include agents. The agents can reduce bioburden, or the number of bacteria present, on the skin of the patient. In some examples, the agent can be an antimicrobial agent and / or an antiseptic agent, delivered as a gas, liquid, or solid. The agents can include iodine, chlorhexidine gluconate, and / or silver. In some examples, the agent can include octenidine dihydrochloride (OCT), polyhexamethylene biguanide (PHMB), povidone- iodine, super-oxidized hypochlorous acid (HOC1), and / or sodium hypochlorite (NaOCl). In some examples, the contact layer 12 can include moisturizing or hydrating agents. These agents can include petrolatum, plant oils, waxes, silicone formulations, glycerol, sorbitol, glycerin, urea, lactic acid, hyaluronic acid, lanolin, paraffin, and / or ceramides.

[0046] In some examples, the tissue conditioning device 4, or dressing, can be translucent. The tissue conditioning device 4 may be translucent without being optically clear. A user, for example a healthcare professional, can assess the color and condition of the skin under the tissue conditioning device 4 by examining the skin through the dressing. The spacer materials 14 may include clear filaments or include apertures sized for visibility through the upper and lower faces. The apertures of the spacer material 14 may be aligned such that the skin can be observed through the tissue conditioning device 4. A series of aligned fenestrations in the spacer material 14 can allow the color of the underlying skin to be determined.

[0047] In some examples, the spacer material 14 can have large fenestrations on the upper surface of the spacer material 14. The spacer material 14 may not need to wick liquids from the lower surface to the upper surface due to the lack of wound exudate at the tissue site, so the fenestrations can be larger than those in spacer materials used for wound dressings.

[0048] In some examples, the spacer material 14 closer to the contact layer 12 can have smaller fenestrations than the spacer material 14 closer to the top film 6. The spacer material 14 closer to the contact layer 12 can have smaller fenestrations to ensure known and suitably homogenous pressure across the skin is maintained. In some examples, the fenestrations can be sized to ensure visibility of the tissue site without being large enough to have pockets for the tissue to be sucked in, which could cause blisters. In some examples, each fenestration can have a width of at least 1 mm and / or less than or equal to 3 mm. Each fenestration can have a width of at least 0.5 mm and / or less than or equal to 5 mm. Each fenestration can have a width of at least 0.25 mm and / or less than or equal to 10 mm. The fenestrations can be elliptical, circular, ovoid, square, diamond, rectangular, hexagonal, and / or octagonal. The width can be the diameter of the fenestration. For avoiding blisters, the fenestrations can have a maximum width of 12 mm. The fenestrations can have a maximum width of 6 mm to further avoid blisters. Fenestrations that are more isometric shapes, for example circular or hexagonal fenestrations, can have lower maximum dimensions. Fenestrations that are more anisotropic shapes, for example rectangular or slit-shaped fenestrations, can have higher maximum dimensions, for example above 12 mm. Anisotropic fenestrations can have a length of less than or equal to 15 mm. Anisotropic fenestrations can have a length of less than or equal to 20 mm.

[0049] In some examples, the spacer material 14 can provide an interconnected gas path that remains open while the top film 6 pushes down due to the differential between atmospheric pressure and the evacuated core of the tissue conditioning device 4. Advantageously, because liquid management is not as necessary as it is in wound care, the spacer material 14 can include solid or hollow frameworks that allow gaseous communication through hollow scaffolds. In another embodiment, the tissue conditioning device 4 can include the top film 6 tented over a scaffold of spacer material 14 for the gaseous pathways. The top film 6 can collapse under negative pressure. The spacer material 14 can be a fabric air mesh, a vacuum breather layer, a vacuum bleeder layer, breather fabric, or a net. The spacer material 14 can distribute vacuum across the surfaces of molds. The spacer material 14 can be flexible, drapable, and allow uniform distribution of negative pressure. The spacer material 14 can be a three-dimensional knit pattern. For example, the spacer material 14 can be a nylon knit and / or a knit scaffold partially embedded in a silicon membrane. Advantageously, this can allow for a thin intermediate air gap between top film and skin contact layer. The spacer material 14 can be a woven spacer material.

[0050] In some examples, the spacer material 14 can be a material that remains porous under negative pressure. In some examples, the spacer material 14 can be a material that retain interconnected void spaces under negative pressure. For example, the spacer material 14 can withstand negative pressure in the range of -60 to -100 mmHg. The spacer material 14 can withstand negative pressure in the range of -60 to -140 mmHg. The spacer material 14 can withstand negative pressure in the range of -40 to -200 mmHg. The spacer material 14 can withstand negative pressure in the range of -20 to -400 mmHg. In some examples, foam, gauze, or another non-woven material can be used to distribute the vacuum.

[0051] In some examples, the tissue conditioning device 4 can be slim and comfortable for patient wear. The tissue conditioning device 4 can be stretched, rolled, and / or scrunched without damaging the device. The tissue conditioning device 4 may lack an absorbent pad due to liquid management being less necessary. The tissue conditioning device 4 may be used to prepare skin, tissue, and / or an incision prior to a surgical procedure.

[0052] In some examples, the apparatus 4 can include a thin layer, for example a pad, film, or membrane. The thin layer can be used to mask the spread of fluid and / or reinforce the top film 6 by withstanding mechanical stresses from the spacer material, which may be sharp. The thin material can be classed as a constructional barrier material between the spacer cut edges and switchable top-film.

[0053] In some examples, the tissue conditioning device 4 can include sensors to baseline and monitor blood perfusion, oxygen saturation, temperature, and / or limb range of motion. The tissue conditioning device 4 can include a processor to receive measurements from the sensors and communicate the results to a user display.

[0054] In some examples, the tissue conditioning device 4 can connect with a nitric oxide gas delivery system. The nitric oxide gas delivery system can deliver nitric oxide to the tissue site through the tissue conditioning device 4. Alternatively, nitric oxide may be delivered transdermally from a liquid or solid. For example, from a hydrogel positioned within or attached to the dressing or applied separately.

[0055] In some examples, the tissue conditioning device 4 can include a heating component. The heating component can warm the tissue site and create normothermic conditions prior to incision and / or surgical procedures. The heating component can be heat reflective material, heat insulative material, and / or an active thermal heating device. The heating component can be attachable or integral with the tissue conditioning device 4. The heat reflective material can include aluminized mylar, metalized polyethylene terephthalate, reflective foil, ceramic coating, graphene, and / or aerogel composites. The heat insulative material can include polyurethane foam, silicone foam, aerogel, cotton wool, fleece, neoprene, closed-cell foam, polyethylene foam, and / or silica-based gel. The active thermal heating device can include electric heating pads, far infrared heating pads, battery powered heat wraps, self-heating patches, heat therapy gel packs, thermal heating bands, and / or hydrocollator heating pads. In some examples, Pico™ dressing can be utilized for applying negative pressure pre- operatively. The advantages of treating the wound site with negative pressure wound therapy include, among others, increased perfusion, reduction in oedema, disinfection, or decontamination. In some cases, positive pressure can be applied pre-operatively in addition to or instead of applying negative pressure and any of the examples described herein can apply positive pressure alone or in combination with negative pressure. Such pre-operative treatment of the wound site (sometimes referred to as tissue conditioning) can improve overall wound healing outcomes. For instance, most surgical infections are a result of the patient’ s own dermal flora contaminating the wound. By increasing blood flow prior to the surgery, the tissue can be primed to be able to rapidly supply the body’s own defensive biochemistry and nutrients for cells. By reducing the bioburden on the patient’s skin there may be a smaller chance that sufficient flora can enter the wound (for instance, the incision) and cause an infection. Keeping the tissue elastic and flexible through optimizing moisture content can reduce stress on wound closure modalities (such as, sutures, clips, or glue), thus reducing the chance of dehiscence.

[0056] In some examples, the apparatus 2 can be used to treat a surgically incised tissue site after a surgical procedure. The apparatus 2 can improve blood perfusion at or near the incised tissue site. The apparatus 2 can be used to apply negative pressure to the incised tissue site. The negative pressure delivery system may lack a cannister. Negative pressure may be conducted with a vacuum source or pump that is not connected to a cannister.

[0057] Figures 2A and 2B show other examples of a tissue conditioning device 204. The tissue conditioning device 204 can include any of the features of the tissue conditioning device 4 of Figures 1 A and IB.

[0058] In some examples, the tissue conditioning device 204, or tissue conditioning interface, can include a cover layer 206. The tissue conditioning device 204 can include a manifold structure 220 under the cover layer 206. The tissue conditioning device 204 can include a peripheral seal 222a, b around the periphery of the tissue conditioning device 204.

[0059] In some examples, the cover layer 206 can be a flexible, extensible layer. For example, the cover layer 206 can be made of polymer film. The cover layer 206 can include an aperture 224 for application of positive or negative pressure through a conduit 226. The cover layer 206 can have a moisture vapor permeability (MVP) of at least about 500 and / or less than about 30,000 grams per meter square in 24 hours. The cover layer 206 can have an MVP of at least about 500 and / or less than about 50,000 grams per meter square in 24 hours. The cover layer 206 can have an MVP of at least about 200 and / or less than about 80,000 grams per meter square in 24 hours. The cover layer 206 can have an MVP of at least about 100 and / or less than about 300,000 grams per meter square in 24 hours. Advantageously, the high MVP can help prevent maceration of tissue, particularly at near the peripheral seal 222a, b. For shorter periods of time, the MVP of the cover layer 206 can be lower. Shorter periods of time can be 20-30 minutes, 10-40 minutes, or under one hour.

[0060] In some examples, the manifold structure 220 can be a material capable of delivering fluids at a certain pressure substantially uniformly across the tissue facing surface. The pressure can be greater than about -250 mmHg or less than about 250 mmHg. The pressure can be greater than about -500 mmHg or less than about 500 mmHg. In some examples, the manifold structure 220 may be capable of withstanding a vacuum (a pressure below atmospheric pressure) and / or a compressive force. The manifold structure 220 may be capable of withstanding a combination of the vacuum and the patients weight and still deliver fluid uniformly. The manifold structure 220 can include a 3D knitted material, foam, non-wovens, a molded or embossed surface, and / or a sintered material.

[0061] In some examples, the peripheral seal 222a, b can include a pressure-sensitive adhesive. As shown in Figure 2A, the peripheral seal 222a can extend only along the outer edge of the tissue conditioning device 204. As shown in Figure 2B, the peripheral seal 222b can extend across substantially the entire lower surface of the tissue conditioning device 204 excluding the aperture 224. In some examples, the adhesive can be applied to substantially the entire periphery of the tissue facing side of the cover layer 206. In some examples, there can be at least one hole at the bottom of the peripheral seal 222b corresponding to the hole in the cover layer 206. The adhesive can take the form of a pattern with holes. Suitable seal material may include pressure sensitive adhesive formed from polymers or natural resins, including acrylic based polymers and silicone-based polymers. The adhesive can include a hydrocolloid adhesive. Pressure sensitive adhesives can include soft gel adhesives. For example, soft silicone gels and / or soft polyurethane gels can be pressure sensitive adhesives.

[0062] In some examples, the tissue conditioning device 204 can be connected to a vacuum pump delivering pressure of at least about 20 and / or less than about 250 mmHg. In some examples, the tissue conditioning device 204 can be connected to a vacuum pump delivering pressure of at least about 10 and / or less than about 500 mmHg. The vacuum pump can be used for application of a sub-atmospheric pressure (SAP) to the tissue site prior to an operative incision.

[0063] In some examples, the pump can deliver continuous or cyclic pressure. The pump may be connected wirelessly to servers for collection of data including actual pressures, chronological data, device identification, patient motion and patient vital signs, and / or partial pressures of gases.

[0064] Figure 3 shows the tissue conditioning device 204 of Figure 2A connected to a fluid delivery system 300.

[0065] As explained elsewhere here, in some examples, the fluid delivery system can deliver fluid from a fluid supply 330. The fluid supply 330 can be a gas or plasma supply. The fluid supply 330 can be a therapeutic conditioning gas (TCG) supply. The TCG can include nitric oxide, oxygen ozone, hydrogen peroxide, water, iodine, or a combination thereof. The fluid supply 330 can be an antibacterial gas, antimicrobial gas, or antiseptic gas. The antibacterial gas, antimicrobial gas, or antiseptic gas can reduce the bioburden of the tissue site.

[0066] In some examples, the fluid delivery system 300 can include a pressurized canister with valves to control delivery of the fluid. A pump may be used to control delivery of the gas. Solid Iodine may be added into the fluid delivery system 300 by connection of a gas-tight vial containing the solid iodine. Iodine may be added into the fluid delivery system 300 by insertion of a known amount of iodine into the fluid delivery system 300.

[0067] In some examples, the gas may be dissolved in a solvent. For example, the gas may be dissolved in water and / or suitable alcohol. The gas can be supplied into the fluid delivery system 300 without the liquid coming into contact with the tissue, for example due to dissolution of the gas from the solvent due to the vapor pressure of the gas above the solvent.

[0068] In some examples, a vessel containing the TCG may be attached to valve 332. When the valve 332 is opened, gas can enter the fluid delivery system 300 while liquid solvent remains in the vessel. The pressure in the system may be reduced to SAP before delivering the fluid. The fluid at a pressure higher than the chosen SAP may be allowed to enter the valve 332.

[0069] In some examples, the concentration of the gas or partial pressure may be controlled by premixing TCG in known quantities with sterile gases. The sterile gas can include air, nitrogen, and / or argon. In some examples, the fluid delivery system 300 may be evacuated to SAP 120 mmHg below ambient. The fluid delivery system 300 may be evacuated to SAP greater than about 90 mmHg and / or less than about 150 mmHg below ambient. The fluid delivery system 300 may be evacuated to SAP greater than about 40 mmHg and / or less than about 200 mmHg below ambient. The fluid can be evacuated using a pump 334. Control of the pressure may be carried out using a controller. The controller can receive measurements from a pressure sensor 336 connected to the tissue conditioning device 204 via a conduit 226. The TCG can be allowed into the system by opening valve 332 until the pressure has risen towards atmospheric. Atmospheric pressure can be about 20 mmHg below ambient pressure. Atmospheric pressure can be greater than about 5 mmHg and / or less than about 50 mmHg below ambient pressure.

[0070] In some examples, a user can turn on the vacuum to evacuate the fluid delivery system 300. The process of evacuating the fluid delivery system 300 can be repeated to purge the system so that there is a partial pressure of the TCG within the fluid delivery system 300 and acting on the tissue. The fluid delivery system 300 may operate at SAP while the remaining gas in the system is enriched with the TCG.

[0071] In some examples, the process of purging and adding gases may be carried out at positive pressure above ambient. The fluid delivery system 300 may be vented to about atmospheric pressure via another valve (not shown). A second charge of gas can be added and the process can be repeated until a desired concentration of gas is present in the fluid delivery system 300. Purging and pressure cycles may be controlled by a controller 338. The controller 338 may be connected to a user interface 340. The user interface 340 may include another controller. The user interface 340 may be connected to the controller 338 by wired or wireless connection. The user interface 340 may be remote from the rest of the device components.

[0072] In some examples, gas can be added to the fluid delivery system 300 to achieve a positive pressure in the fluid delivery system 300. These processes may be controlled by a microcontroller, microprocessor, suitable circuitry, and / or programming. Alarms may be provided to the user to alert them when the therapy is outside normal parameter. Such alarms may include the system pressure being outside limits or gas concentration outside limits.

[0073] Figure 4 shows an example of the tissue conditioning device 204 of Figure 2A connected to another example of a fluid delivery system 400.

[0074] In some examples, the fluid delivery system 400 can include any of the features of the fluid delivery system 300 of FIG. 3.

[0075] In some examples, the tissue conditioning device 204, or tissue conditioning interface, can be connected by two conduits 426a, b to fluid supplies 430a,b. In some examples, the conduits 426a, b may be attached to each other. In some examples, the conduits 426a, b may be extruded as a multi-lumen single extrusion. The conduits 426a, b may be constructed of a welded film construction.

[0076] In some examples, delivery of suitable therapeutic gases into the system may controlled by valve 432a and / or valve 432b. The fluid delivery system 400 may be used to add therapeutic gas and / or plasma using valve 432b while simultaneously applying SAP via valve 432a. Advantageously, this can allow for the introduction of the therapeutic gas thus allowing rapid purging of the fluid delivery system 400. In some examples, the pressure in the system can be reduced to SAP, and then the fluid at a higher pressure than the chosen SAP may be allowed to enter through valve 432b. The concentration and / or partial pressure of the gas may be controlled by premixing TCG in known quantities with sterile gases. In some examples, the pressure sensors 436a,b connected to the conduits 426a, b can control the evacuation of the fluids. In some examples, it can be possible to detect blockages and / or leaks in the fluid delivery system 400 by monitoring the pressures at the pressure sensors 436a,b.

[0077] In some examples, the fluid delivery system 400 can include a processor that compares the pressure measurements at the two pressure sensors 426a, b. The processor can determine that a leak is present in the fluid delivery system 400 when the pressure measured at pressure sensor 426b is closer to atmospheric than the pressure measured at pressure sensor 426a when applying SAP. The processor can determine that a blockage is present in the fluid delivery system 400 if a positive pressure is applied via valve 432b and the pressure measured at valve 432a is none. When applying positive pressure via valve 432b, if the pressure measure at pressure sensor 426b is greater than the pressure measured at pressure sensor 426a, the system can be diagnosed as having a leak. In some examples, the fluid supply 430a may be open to the atmosphere. By controlling the opening of valve 432a, the pressure may be adjusted back to atmospheric in a controlled manner. In some examples, the pressures in the fluid delivery system 400 can be varied over time.

[0078] In some examples, sensors may be included within the fluid delivery system 400. Sensors may be positioned within the tissue conditioning device 204 such that they contact the tissue. Sensors may also be positioned within the tissue conditioning device 204 such that they are not in direct contact with the tissue. The sensors can be positioned on or within the contact layer or the manifold structure 222. Sensors may be positioned within the conduits 426a, b or within any devices connected to the conduits 426a, b for application of therapy. Sensors may be positioned on a separate conduit communicating fluidically with the tissue conditioning device 204. In some examples, the sensors may be positioned outside the device on the cover layer 206. The sensors may measure the concentrations of gases present within the system and / or the tissue. In some examples, the sensors can measure the oxygen levels, nitric oxide levels, humidity (water vapor) levels, blood oxygen levels, tissue stiffness, and / or another parameter. In some examples, the sensors can be particularly designed to measure volatile organic compounds (VOC). The VOC may be generated as the result of flora on the tissue. The VOC level and / or other sensor reading may be presented to the user as an indication of the levels of flora on the tissue. The VOC may be used as an indication that the tissue has been conditioned or is in need of further conditioning. In some examples, a low VOC level, high blood oxygen readings, and / or low tissue stiffness may indicate a tissue is primed and ready for an incisional procedure. In some examples, a high VOC level, low blood oxygen readings, and / or high tissue stiffness may indicate a tissue is not ready for an incisional procedure.

[0079] Figures 5A-5B show other examples of a tissue conditioning device 504.

[0080] In some examples, the tissue conditioning device 504 may include any of the features of the tissue conditioning device 204 of FIG.s 2A-2B. The tissue conditioning device 504 may be connectable with any of the fluid delivery systems described with respect to FIGs. 3 and 4.

[0081] In some examples, the tissue conditioning device 504 may include a tissue contact layer 548. Tissue contact layers 548 may be made from flexible polymers. For example, tissue contact layers 548 may be made from polyurethane, polyethylene, ethyl vinyl acetate, and / or polyester. Tissue contact layers 548 may be porous to fluid and / or contain perforations. Tissue contact layers 548 may serve to maintain the construction of the device and / or prevent the manifold from irritating the tissue. As shown in FIG. 5A, a seal adhesive 546 may be in the form of a layer around the periphery of the tissue contact layer 548. As shown in FIG. 5B, the seal adhesive 546 can cover the majority of the wound facing side of the tissue contact layer 548 with through holes aligned with perforations in the tissue contact layer 548. In some examples, the tissue contact layer 548 may include a pressure sensitive adhesive on the cover layer 506.

[0082] Figures 6A-6D show other examples of a tissue conditioning device 604.

[0083] In some examples, the tissue conditioning device 604 may include any of the features of the tissue conditioning device 204 of FIG.s 2A-2B and the tissue conditioning device 504 of FIG.s 5A-5B. The tissue conditioning device 604 may be connectable with any of the fluid delivery systems described with respect to FIGs. 3 and 4.

[0084] In some examples, the tissue conditioning device 604 can include a gas impermeable layer 650a,b,c,d. The border of the dressing in contact with tissue can allow gases to pass through it, whereas the central area enclosing the manifold structure 620 can remain substantially gas tight. The gas impermeable layer 650a,b,c,d may be constructed from polyester, polyethylene terephthalate, polyethylene, polyvinylidene Fluoride, silicone, polyurethane, metal foil and / or another suitable material capable of reducing the gas permeability. The gas impermeable layer 650a,b,c,d may be adhered directly through spraying, coating, and / or laminating as a film to the cover layer 606. The gas impermeable layer 650a,b,c,d may be adhered using heat and pressure. The gas impermeable layer 650a,b,c,d may be laminated as a film using adhesive.

[0085] In some examples, as shown in FIGs. 6A and 6C, the gas impermeable layer 650a, c may be positioned below the cover layer 606. As shown in FIGs. 6B and 6D, the gas impermeable layer 650b, d may be positioned above the cover layer 606. In some examples, where the gas impermeable layer 650a,b,c,d is less extensible, the gas impermeable layer 650a,b,c,d may contain slits to allow the material to extend when subjected to an extensive force. In some examples, a pressure sensitive adhesive may be applied to the tissue facing side of the cover layer 606 to reduce the gas permeability of the cover layer 606. The pressure sensitive adhesive can be acrylic adhesive. The adhesive can be applied in the form of a discontinuous layer.

[0086] In some examples, as shown in FIGs. 6A and 6B, the adhesive 646 can cover substantially the entire tissue facing side of the tissue conditioning device 604. As shown in FIGs. 6C and 6D, the adhesive 646 can cover the periphery of the tissue conditioning device 604. The adhesive can be arranged in a pattern or grid. Varying the area of coated by adhesive can vary the gas permeability of the various areas of the tissue conditioning device 604. For example, the border region may contain a low area of adhesive when compared to the area of adhesive covering the manifold structure 620. Application of an adhesive to the tissue facing side of the cover layer may help in securing the construction of the tissue conditioning device 604. In some examples, wearing the tissue conditioning devices described herein can allow the patient to become accustomed to wearing a negative pressure system. This can reduce the time needed for the patient to get used to using post-operative negative pressure systems. Advantageously, the tissue conditioning device can enable a consistent approach to skin preparation across multiple surgical specialties. The same tissue conditioning device can be used before surgical operations in the fields of general surgery, orthopedic surgery, plastic surgery, trauma surgery, and / or other fields. The uniformity of the design across the fields of surgical operations can allow healthcare workers and / or patients to become accustomed to this device. The tissue conditioning devices described herein can reduce or control bacterial burden before surgery. The tissue conditioning devices described herein can control the skin biome. The tissue conditioning devices described herein can improve patient compliance by minimizing the burden on the patients to prepare the incision site themselves. The tissue conditioning devices described herein, for example those with a high MVP top film, can manage sweat from the patient during wear. Skin Perfusion Pressure Determination

[0087] In some examples, a skin perfusion pressure determination device can be used to measure a blood perfusion or blood perfusion pressure at a target tissue area. In order to assess the health or healing of a wound or tissue area, the skin perfusion pressure determination device may be used to measure a parameter associated with wound healing at various target tissue areas. In some embodiments, the various target tissue area can be various points about the perimeter of the dressing. For example, the skin perfusion pressure determination device can provide a measurement of the amount of blood perfusion in the tissue surrounding the wound. In other embodiments, the target tissue area can be healthy tissue or tissue not associated with a wound. In some embodiments, the skin perfusion pressure determination device can be used in combination with other sensor enabled devices. For example, the skin perfusion pressure determination device can be used in combination with or in coordination with a sensor enabled dressing or contact layer as described in more detail in International Application No. PCT / IB2017 / 000693, filed May 12, 2017, published as WO 2017 / 195038 on November 16, 2017, titled "SENSOR ENABLED WOUND MONITORING AND THERAPY APPARATUS," the disclosure of which is hereby incorporated by reference herein in its entirety. In some embodiments, the skin perfusion pressure determination device can be incorporated into various medical devices or apparatuses as described in more detail in International Application No. PCT / EP2018 / 055940, filed March 9, 2018, titled “DEVICE, APPARATUS AND METHOD OF DETERMINING SKIN PERFUSION PRESSURE,” the disclosure of which is hereby incorporated by reference herein in its entirety.

[0088] In some examples, the skin perfusion pressure determination device can determine the skin perfusion pressure or a measurement or index of skin perfusion pressure by positioning a proximal end of a skin perfusion pressure determination device on a target area of patient, the skin perfusion pressure determination device comprising a bellows portion. A force can be applied to the skin perfusion pressure determination device against the target area, causing the bellows portion to contract. The force and / or pressure applied to the target area by the skin perfusion pressure determination device can be measured using a first sensor within the device. The blood perfusion in the target area beneath the proximal end can be measured using a second sensor within the device. After the device detects that blood flow has been occluded in the target area, the force applied to the target area at a controlled rate can be released at a controlled rate by expanding the spring and the bellows portion as described herein. As used herein, obtaining or determining a skin perfusion pressure or taking a skin perfusion pressure measurement can refer to obtaining or determining an index or measurement which is based on a perfusion pressure and does not require that the perfusion pressure itself be measured. Additionally, as used herein, the one or more sensors used to sense or detect a parameter associated with an amount of blood perfusion at the target area can be detecting the onset of the pulse waveform (i.e. the onset of blood flow into the tissue) and / or the amount of perfusion. In some embodiments, the one or more sensors used to sense or detect a parameter associated with an amount of blood perfusion at the target area can detect that perfusion occurring and not necessarily how much or the amount of blood perfusion. For example, the one or more sensors used to sense or detect a parameter associated with an amount of blood perfusion at the target area can determine a measure for when perfusion starts or exists in a tissue area.

[0089] The skin perfusion pressure determination device can utilize various designs such as described above and as further described herein incorporating the sensors and signal processing elements into an elongate housing. In some embodiments, the skin perfusion pressure determination device described herein can be incorporate various features of the skin perfusion pressure determination device described in International Application No. PCT / EP2018 / 055940, filed March 9, 2018, titled “DEVICE, APPARATUS AND METHOD OF DETERMINING SKIN PERFUSION PRESSURE,” the disclosure of which is incorporated by reference herein. In some embodiments, the skin perfusion pressure determination device can incorporate features of International Application No. PCT / EP2018 / 055940, including, but not limited to, the displays, indicators, LEDs, symbols, methods of use, and any other features described in more details therein.

[0090] In some cases, the skin perfusion pressure determination device can be used to capture various measurements. First, a force can be applied to a target area with the proximal end of the skin perfusion pressure determination device and blood flow is occluded. The force at which blood flow is occluded can be the data point captured. The measurement can end and a pressure can be calculated if desired.

[0091] In another case, a force can be applied to a target area with the proximal end of the skin perfusion pressure determination device and blood flow is occluded. Then the force applied can be reduced and blood flow can be restored. The force at which blood flow is restored can be the data point captured. The measurement can end and a pressure can be calculated if desired.

[0092] In another case, a force can be applied to a target area with the proximal end of the skin perfusion pressure determination device and blood flow is occluded. Then the force applied can be reduced and blood flow can be restored. The force at which blood flow is occluded and blood flow is restored can be the data captured. The measurement can end and pressure can be calculated for these two data points if desired.

[0093] It will be appreciated that the blood perfusion sensor may comprise other types of optical sensors or may be a non-optical sensor, the skin perfusion pressure determination device could comprise other types of data storage devices. It will also be appreciated that, where applicable, each embodiment described previously could be modified so that recorded data is processed and / or stored locally on a skin perfusion pressure determination device or transmitted for remote processing and / or storage and vice versa.

[0094] The embodiments described above comprise a sensor module which is configured such that an optical sensor can be positioned adjacent the skin and a force sensor is located above the optical sensor. Other possible arrangements include a sensor module in which a force sensor and an optical sensor are arranged such that, in use, the force sensor is placed next to a target region of skin tissue and the optical sensor is positioned above the force sensor. In such an arrangement, the force sensor may comprise through-holes or transparent portions through which light can be transmitted.

[0095] In some cases, an accelerometer, magnetometer, gyroscope, any other sensor, a comparison to an external feature, and / or tilt sensor can be used which can be used to determine the angle of application of force. Knowing the angle of application of force can allow for numerical compensation for this angle and / or warning of the user if this angle gets too large as this can impact the reading. In some cases, reaching certain angular points can prevent a reading from being taken, or the data from being reliable.

[0096] In any embodiment of the claims where the term “pressure” is used, the term “pressure” is considered to be interchangeable with “force.” For example, with respect to Claim 1 of the PCT application as filed, a skin perfusion pressure determination device may be configured to exert a force on the target area and a sensor module may be configured to detect a force exerted on the target area. Moreover, the display can display a force or a calculated pressure.

[0097] Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to” and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise. Features, integers, characteristics or groups described in conjunction with a particular aspect, embodiment or example of the disclosure are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of the features and / or steps are mutually exclusive. The disclosure is not restricted to any details of any foregoing embodiments. The disclosure extends to any novel one, or novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

[0098] The reader’s attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

Claims

WHAT IS CLAIMED IS:

1. A method of preparing a tissue site for a surgical procedure, the method comprising: positioning a tissue conditioning device over a skin site identified for surgical incision, the tissue conditioning device comprising: a top film; a skin contact layer; and a compression-resistant spacer material between the top film and the skin contact layer; and applying negative pressure through the tissue conditioning device to the skin site to increase blood perfusion below the skin site prior to surgical incision of the skin site.

2. The method of claim 1, wherein the tissue conditioning device is wearable.

3. The method of any one of claims 1 or 2, wherein applying negative pressure comprises applying negative pressure constantly for a period of at least 1 day and less than 7 days.

4. The method of any one of claims 1 or 2, wherein applying negative pressure comprises applying negative pressure constantly for a period of between at least 3 days and less than 5 days.

5. The method of any one of claims 1-4, wherein the tissue conditioning device further comprises a pressure sensitive adhesive on a distal side of the top film.

6. The method of any one of claims 1-5, further comprising delivering an antiseptic agent or an antimicrobial agent to the skin site using the tissue conditioning device.

247. The method of any one of claims 1-6, further comprising determining a quality of the skin site by viewing the skin site while the tissue conditioning device is positioned over the skin site, wherein the tissue conditioning device is translucent.

8. The method of claim 7, wherein the compression-resistant spacer material of the tissue conditioning device comprises fenestrations sized for increasing visibility of the skin site.

9. The method of any one of claims 1-8, further comprising delivering a therapeutic conditioning gas to the skin site through the tissue conditioning device.

10. The method of claim 9, further comprising simultaneously delivering the therapeutic conditioning gas and the negative pressure.

11. The method of any one of claims 1-10, further comprising delivering nitric oxide to the skin site through the tissue conditioning device.

12. The method of any one of claims 1-11, further comprising measuring at least one of amount of volatile organic compounds, blood oxygen, or tissue stiffness using a sensor on the tissue conditioning device.

13. The method of claim 12, further comprising determining whether a tissue is ready for an incisional procedure based on at least one of the amount of volatile organic compounds, blood oxygen, or tissue stiffness.

14. A system for providing negative pressure in preparation for a surgical procedure comprising: a tissue conditioning device configured to be positioned over a skin site identified for surgical incision, the tissue conditioning device comprising: a top film; a skin contact layer; anda compression-resistant spacer material between the top film and the skin contact layer; a conduit, a distal end of the conduit configured to connect to the tissue conditioning device; a valve configured to allow fluid to enter the conduit when the valve is open; a pump configured to evacuate gas from the conduit; and a pressure sensor configured to measure pressure in the conduit.

15. The system of claim 14, further comprising a controller configured to receive measurements from the pressure sensor and control at least one of the valve or the pump based on the measurements.

16. The system of any one of claims 14 or 15, further comprising a user interface configured to display measurements of the pressure sensor.

17. The system of any one of claims 14-16, further comprising: a second conduit, a distal end of the second conduit configured to connect to the tissue conditioning device; a second valve configured to allow fluid to enter the second conduit when the second valve is open; and a second pressure sensor configured to measure pressure in the second conduit.

18. The system of claim 17, further comprising a controller configured to receive measurements from the pressure sensor and the second pressure sensor and control at least one of the valve, the second valve, or the pump based on the measurements.

19. The system of any one of claims 17 or 18, further comprising a user interface configured to display measurements of at least one of the pressure sensor or the second pressure sensor.

20. The system of any one of claims 14-19, wherein the tissue conditioning device is wearable.

21. The system of any one of claims 14-20, wherein the tissue conditioning device further comprises a pressure sensitive adhesive on a distal side of the top film.

22. The system of any one of claims 14-21, wherein the tissue conditioning device is configured to deliver an antiseptic agent or an antimicrobial agent to the skin site.

23. The system of any one of claims 14-22, wherein the tissue conditioning device is translucent.

24. The system of any one of claims 14-23, wherein the compression-resistant spacer material of the tissue conditioning device comprises fenestrations sized for increasing visibility of the skin site.

25. The system of any one of claims 14-24, wherein the tissue conditioning device is configured to deliver a therapeutic conditioning gas to the skin site.

26. The system of claim 17, wherein the conduit is configured to deliver negative pressure to the skin site while the second conduit simultaneously delivers a therapeutic conditioning gas to the skin site.

27. The system of any one of claims 14-26, wherein the tissue conditioning device is configured to deliver nitric oxide to the skin site.

28. The system of any one of claims 14-27, further comprising measuring a sensor on the tissue conditioning device configured to measure at least one of amount of volatile organic compounds, blood oxygen, or tissue stiffness.

129. A method of preparing a tissue site for a surgical procedure, the method comprising: positioning a tissue conditioning device over a skin site identified for surgical incision, the tissue conditioning device comprising: a top film; a skin contact layer; and a compression-resistant spacer material between the top film and the skin contact layer; and delivering a gas through the tissue conditioning device to the skin site to reduce a bioburden of the skin site before the surgical incision of the skin site, wherein the gas comprises at least one of antibacterial gas, antimicrobial gas, or antiseptic gas.

30. The method of claim 29, wherein the tissue conditioning device is wearable.

31. The method of any one of claims 29 or 30, wherein the tissue conditioning device further comprises a pressure sensitive adhesive on a distal side of the top film.

32. The method of any one of claims 29-31, further comprising applying negative pressure to the skin site using the tissue conditioning device.

33. The method of any one of claims 29-32, further comprising determining a quality of the skin site by viewing the skin site while the tissue conditioning device is positioned over the skin site, wherein the tissue conditioning device is translucent.

34. The method of claim 33, wherein the compression-resistant spacer material of the tissue conditioning device comprises fenestrations sized for increasing visibility of the skin site.

35. The method of any one of claims 29-34, further comprising delivering a therapeutic conditioning gas to the skin site through the tissue conditioning device.

36. The method of claim 35, further comprising simultaneously delivering the therapeutic conditioning gas and the gas.

37. The method of any one of claims 29-36, further comprising delivering nitric oxide to the skin site through the tissue conditioning device.

38. The method of any one of claims 29-37, further comprising measuring at least one of amount of volatile organic compounds, blood oxygen, or tissue stiffness using a sensor on the tissue conditioning device.

39. The method of claim 38, further comprising determining whether a tissue is ready for an incisional procedure based on at least one of the amount of volatile organic compounds, blood oxygen, or tissue stiffness.

40. A method of treating a tissue site after a surgical procedure, the method comprising: positioning a tissue conditioning device over a surgically incised skin site, the tissue conditioning device comprising: a top film; a skin contact layer; and a compression-resistant spacer material between the top film and the skin contact layer; and applying negative pressure through the tissue conditioning device to the skin site to increase blood perfusion below the skin site after surgical incision of the skin site.

41. The method of claim 40, wherein the negative pressure is applied from a negative pressure source without a canister.29

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