WO2015116823A1 - System and method for wound imaging and debridement - Google Patents

Abstract

According to the disclosed embodiments, a debridement accessory arrangement debrides necrotic tissue present in a wound of a patient and includes one or more debridement accessories, such as a microneedle array, pH-responsive bristles, and a debriding agent- embedded pH-responsive polymer film. A dual pressure wound therapy (DPWT) unit is coupled to the debridement accessory arrangement and is configured to intermittently apply positive and negative pressure to the wound in conjunction with the debriding of the necrotic tissue by the debridement accessory arrangement. Also, according to the disclosed embodiments, an image of a wound of a patient is acquired. Then, a multi-dimensional image of the wound is generated based on the acquired image, an amount of wound perfusion of the wound is measured based on the acquired image using superpixel image analysis, and a frequency-based histogram of the wound perfusion is generated.

Description

SYSTEM AND METHOD FOR WOUND IMAGING

AND DEBRIDEMENT

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to, and the benefit under 35 U.S.C. § 119(e) of U.S. provisional patent application No. 61/932,940, entitled "An Integrated Chronic Wound Debridement and Healing System," filed January 29, 2014, and of U.S. provisional application No. 61/989,207, entitled "System and Method for Wound Imaging and

Debridement," filed May 6, 2014. The entire contents of the aforementioned patent applications are incorporated herein by this reference.

TECHNICAL FIELD

The present disclosure relates generally to medical devices and techniques, and, more particularly, to wound imaging and debridement.

BACKGROUND

A wound, and particularly an "open wound," is a type of bodily injury in which the epidermis (i.e., skin) is torn, cut, or punctured. Wounds can be categorized as acute (e.g., fast healing) or chronic. Chronic wounds are those that fail to close spontaneously or have not healed within approximately six weeks. These wounds remain in a particular phase of wound healing, such as the inflammatory stage, for longer than normal. Chronic wounds can pose an incredible disease burden to the United States, affecting 8.5 million people every year, over 2% of the population. Moreover, these wounds can cause patients severe emotional and physical stress and create a significant financial burden for patients, as well as the healthcare system as a whole.

One method for treating chronic wounds is debridement, which involves the medical removal of dead, damaged, or infected tissue proximate to the wound. Debridement can help to improve the healing potential of the remaining healthy tissue. There are a number of existing solutions for the debridement of necrotic tissue (i.e., dead tissue), including sharp debridement, mechanical debridement, enzymatic debridement, and biological debridement (e.g., maggot therapy), to name a few. Other effective methods for treating chronic wounds include negative pressure wound therapy (NPWT) and dual pressure wound therapy (DPWT), which are therapeutic techniques using a vacuum-like mechanism to promote wound healing. However, NPWT and DPWT typically cannot be used in wounds with more than 20% necrotic tissue, as overlaying dead tissue hinders the proliferation of the underlying granulation tissue (e.g., new connective tissue and blood vessels that form on a surface of the wound during healing). Therefore, scenarios often arise where NPWT or DPWT treatments cannot be combined with the aforementioned debridement techniques.

Moreover, when assessing a chronic wound (e.g., to determine an appropriate treatment), visual inspection of the wound is commonly used and typically effective. Notably though, visual wound analysis is subjective and may fail to detect wound undermining or deep tissue necrosis. A wide variety of products, including mobile applications, have been developed for the purposes of wound analysis. However, these products lack functionality required to measure and calculate essential metrics, such as wound perfusion, whereby increased wound perfusion is often a sign of improved healing, while ischemia (e.g., a restriction in blood supply to tissues) can indicate further deterioration.

SUMMARY

According to the present embodiments, a system is disclosed for performing selective wound debridement and healing. The embodiments include an integrated system that can debride necrotic tissue in wounds through a variety of techniques, including delivering enzymatic debriding agents within the wound, mechanically debriding necrotic tissue, or dissolving necrotic tissue through osmotic reactions. The system can also perform concurrent debridement by employing intermittent positive and negative pressure (e.g., DPWT) to promote wound healing. The system can be ambulatory such that it may be used at home. The system can also perform continuous debridement and healing for an extended duration before needing to change the dressing, which can also be performed at home.

Further, according to the present embodiments, a system is disclosed for performing wound imaging and perfusion measurements. The embodiments include a computer program that performs a variety of functions, including imaging a wound, calculating the wound area, determining a quantity of necrotic tissue, measuring perfusion in the wound area, and uploading data to a cloud database. In addition, the system can generate a three-dimensional (3D) rendering of the wound surface, thereby facilitating the manufacturing of custom wound dressings that fit the contour of each patient-specific wound. The system can also generate advanced statistics relating to the wound image and calculate trends in wound tissue composition over time.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features, aspects and advantages of the embodiments disclosed herein will become more apparent from the following detailed description when taken in conjunction with the following accompanying drawings.

FIG. 1 illustrates an exemplary integrated chronic wound debridement and healing system.

FIG. 2 illustrates a close-up view of a DPWT unit in the exemplary integrated chronic wound debridement and healing system.

FIG. 3 illustrates exemplary time frequency configurations for a DPWT unit in the integrated chronic wound debridement and healing system in comparison to other pressure wound therapy configurations.

FIG. 4 illustrates an exemplary exudate canister used in the integrated chronic wound debridement and healing system.

FIG. 5 illustrates an exemplary debriding agent canister used in the integrated chronic wound debridement and healing system.

FIG. 6 illustrates an exemplary tube arrangement used in the integrated chronic wound debridement and healing system.

FIG. 7 illustrates an exemplary microneedle applicator and array used in the integrated chronic wound debridement and healing system.

FIGS. 8 A and 8B illustrate a foam pad and microneedle array debridement accessory.

FIGS. 9A-9C illustrate pH-sensitive bristle arrangement debridement accessories.

FIG. 10 illustrates a foam pad and debriding agent-embedded pH-responsive film debridement accessory. FIG. 11 illustrates an exemplary schematic diagram of a controller operable to perform wound imaging and perfusion measurements.

FIGS. 12A and 12B illustrate exemplary interfaces of a wound imaging and perfusion measurement application.

It should be understood that the above-referenced drawings are not necessarily to scale, presenting a somewhat simplified representation of various preferred features illustrative of the basic principles of the disclosure. The specific design features of the present disclosure, including, for example, specific dimensions, orientations, locations, and shapes, will be determined in part by the particular intended application and use environment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or

"comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

It is understood that a number of the below methods are executed by at least one controller. The term "controller" refers to a hardware device that includes a memory and a processor. The memory is configured to store program instructions and the processor is specifically configured to execute said program instructions to perform one or more processes which are described further below.

Furthermore, the controller of the present disclosure may be embodied as non- transitory computer readable media on a computer readable medium containing executable program instructions executed by a processor, controller or the like. Examples of the computer readable mediums include, but are not limited to, ROM, RAM, compact disc (CD)- ROMs, magnetic tapes, floppy disks, flash drives, smart cards and optical data storage devices. The computer readable recording medium can also be distributed in network coupled computer systems so that the computer readable media is stored and executed in a distributed fashion, e.g., by a telematics server or a Controller Area Network (CAN).

FIG. 1 illustrates an exemplary integrated chronic wound debridement and healing system. As shown in FIG. 1, a patient 100 is wearing an integrated chronic wound debridement and healing system 105. The integrated chronic wound debridement and healing system 105 includes a dual pressure wound therapy (DPWT) unit 110 and debridement accessory 120. The integrated chronic wound debridement and healing system 105 may be configured in multiple ways by pairing the DPWT unit 110 with one or more various debridement accessories 120, as described in further detail below.

The integrated chronic wound debridement and healing system 105 is intended to gently and selectively debride necrotic tissue, including eschar and slough from wounds in patients requiring debridement. Notably, the integrated chronic wound debridement and healing system 105 features the ability to integrate debridement with negative, or intermittent positive and negative pressure (e.g., dual), pressure. This combination can provide additional benefits of removing necrotic tissue during dual pressure application to enhance wound healing and further reduce time to wound closure than would be possible using debridement or dual pressure alone. The integrated chronic wound debridement and healing system 105 may perform selective debridement on acute and chronic wounds, burns, ulcers (e.g., pressure, venous stasis, arterial, and diabetic), and traumatic wounds. Therefore, the integrated chronic wound debridement and healing system 105 is particularly useful for patients who would benefit from vacuum-assisted drainage and controlled delivery of wound debriding solutions into the wound.

In addition, the system is portable since the integrated chronic wound debridement and healing system 105 may be attached to the patient 100 in a manner that allows the patient to remain ambulatory. As a result, the integrated chronic wound debridement and healing system 105 may be used at home, hospitals, or other wound care facilities, for periods of several days before the dressing needs to be reapplied (e.g., throughout the duration of time when wound debridement is necessary for healing).

The DPWT unit 110 is a portable device that can be secured to the patient 100. A close-up view of the DPWT unit 110 is shown in FIG. 2. The DPWT unit 110 can deliver negative pressure at any suitable pressure value(s). For example, the DPWT unit 110 could deliver negative pressure at two fixed levels, e.g., -80 mmHg or -120 mmHg. The DPWT unit 110 can also deliver positive pressure at any suitable pressure value(s). For example, the DPWT unit 110 could deliver positive pressure at two fixed levels, e.g., 50 mmHg and 100 mmHg. Furthermore, the DPWT unit 110 can deliver alternating negative and positive pressure at any suitable time frequencies. For example, the DPWT unit 110 may alternate negative and positive pressure, ranging from one minute to ten minutes of positive pressure, and one minute to five minutes of continuous negative pressure.

To this point, FIG. 3 illustrates exemplary time frequency configurations for the DPWT unit 110 in the integrated chronic wound debridement and healing system 105 in comparison to two other pressure wound therapy configurations. In particular, FIG. 3 depicts: i) a negative pressure wound therapy (NPWT) unit with a constant vacuum (e.g., "constant VAC") operating at -80 mmHg; ii) a NPWT unit with an intermittent vacuum (e.g., "intermittent VAC") whose operation alternates between -80 mmHg and 0 mmHg; and iii) the DPWT unit 110 of the disclosed embodiments ("DPWT") whose operation alternates between -80 mmHg and +50 mmHg. It should be understood that the time frequency configuration of the DPWT unit 110 shown in FIG. 3 is for demonstration purposes only and should not be treated as limiting the present disclosure.

The negative and positive pressure may be generated by the DPWT unit 110 using any internal components suitable for causing the necessary negative and/or positive pressure. As an example, an internal vacuum pump (not shown) may be used by the DPWT unit 110 to generate negative pressure. As another example, positive pressure may be generated through a balloon sac (not shown) in the DPWT unit 110. In this case, the balloon sac may be inflated by redirecting air from the vacuum pump to the sac toward the end of a negative pressure cycle. Then, the inflated sac in the DPWT unit 110 may accomplish additional functionality by, for example, applying pressure on the canister containing the debriding agent, as shown in FIG. 5. Therefore, the debriding agent may flow from the canister to the wound area of the patient 100.

The construction and physical arrangement of the DPWT unit 110 may vary. For example, the DPWT unit 110 may have an entry port to the internal vacuum pump and a tube connection from the vacuum pump entry port to an exudate canister, as shown in FIG. 4. The DPWT unit 110 may also have an entry port to a debriding agent gate and a similar tube connection from the debriding agent gate entry port to a debriding agent canister, as shown in FIG. 5. The aforementioned tube connections may be formed of a suitable material, such as polyethersulfone, for example. Additionally, the DPWT unit 110 may be powered with a lithium battery, having a typical battery life of approximately six to ten hours, or powered through an AC connection.

FIG. 4 illustrates an exemplary exudate canister used in the integrated chronic wound debridement and healing system. As shown in FIG. 4, the exudate canister 410 may be connected to the DPWT unit 110. The exudate canister 410 may be coupled to the DPWT unit 110 in any suitable manner, such as via an attachment to the side of the DPWT unit 110 or through an extension tube. The exudate canister 410 may be detachable from the DPWT unit 110, in order for the canister 410 to be emptied or disposed.

As described above, the DPWT unit 110 may have an entry port to the internal vacuum pump and a tube connection from the vacuum pump entry port to the exudate canister 410. As such, exudate collected by the vacuum pump can be emptied into the exudate canister 410. The canister 410 may be any canister suitable for collecting exudate collected from the DPWT unit 110, such as a single-use, latex-free, and sterile 100 cc canister. The exudate canister 410 may be composed of any suitable material, including HTPE or any other biocompatible polymeric material.

FIG. 5 illustrates an exemplary debriding agent canister used in the integrated chronic wound debridement and healing system. As shown in FIG. 5, the debriding agent canister 510 may be connected to the DPWT unit 110. The debriding agent canister 510 may be coupled to the DPWT unit 110 in any suitable manner, such as via an attachment to the side of the DPWT unit 110 or through an extension tube. For example, the canister 510 can slide into the DPWT unit 110 through the debriding agent gate entry port on a side of the DPWT unit 110. The debriding agent canister 510 may slide entirely into the DPWT unit 110, such that a substantial entirety of the canister 510 is contained in the DPWT unit 110. The debriding agent canister 510 may be detachable from the DPWT unit 110, in order for the canister 510 to be emptied or disposed.

As described above, the DPWT unit 110 may have an entry port to a debriding agent gate and a tube connection from the debriding agent gate entry port to the debriding agent canister 510. As such, a debriding agent contained in the debriding agent canister 510 can be released by the canister 510 and delivered to the wound. The debriding agent contained in the debriding agent canister 510 can be released and delivered to a desired location in any suitable manner. For example, the debriding agent canister 510 may have one or more pores on its surface (e.g., an anterior surface) through which the debriding agent can exit the canister 510. Also, an inflatable balloon sac, as described above, can be positioned in the debriding agent canister 510 (e.g., at a posterior end) and can apply pressure on the canister 510 when the debriding agent is to be delivered.

The debriding agent canister 510 may be any canister suitable for containing and delivering a debriding agent, such as a single-use, latex-free, and sterile 20 cc canister. The debriding agent canister 510 may be composed of any suitable material, including HTPE or any other biocompatible polymeric material.

FIG. 6 illustrates an exemplary tube arrangement used in the integrated chronic wound debridement and healing system. The tubing set 600 may be operable to couple the DPWT unit 110 to components, such as the exudate canister 410 and the debriding agent canister 510. Further, the tubing set 600 may be operable to deliver exudate from the wound to the DPWT unit 110 and a debriding agent from the DPWT unit 110 to the wound. The tubing set 600 may include two tube lines that are fused along their lengths at an end where the tube lines enter the DPWT unit 110, but may separate at an end where the tube lines are proximate to the wound site. The tubes may be composed of any suitable biocompatible polymeric material, such as polyethersulfone. The tubes may be of any suitable length and width, depending on the particular arrangement of the integrated chronic wound debridement and healing system 105 on the patient. An exemplary arrangement may necessitate that the tubes are both approximately 35 cm long, as an example.

As shown in FIG. 6, a tubing set 600 includes a first end 610 located proximate to the DPWT unit 110 and a second end 620 located proximate to the wound site of the patient 100. Illustratively, at the first end 610 (e.g., the DPWT unit 110 end), both tubes may enter the device fused, while being internally split, so as to have separate entries to the vacuum port and the debriding agent delivery port, as described above. Meanwhile, at the second end 620 (e.g., the wound site end), the tubes may split a distance away (e.g., a few centimeters) from one another, so as to form two securing surfaces to a foam pad overlaying the wound, as described below. As a result, one tube line can provide negative pressure and can remove wound exudate from the site, capturing any exudate and delivering it to the exudate canister 410. The other tube line can provide positive pressure and can deliver the debriding agent from the debriding agent canister 510.

As is known in the art, a dressing kit (not shown) may be applied to the wound of the patient 100 to promote healing and prevent further harm. The dressing kit, which can be composed of an adhesive drape, plastic film, and a wound ruler, for example, may facilitate communication of the tubing set 600 with the wound of the patient 100. The adhesive drape, which may be composed of polyurethane, for example, can include an acrylic adhesive coating that can adhere to skin and may have an opening therein to allow attachment of the tube line securing surfaces (e.g., at the second end 620). The drape can be customized for the patient 100 by being cut to the shape of the wound. The transparent, plastic film, which may also be composed of polyurethane, can be placed on top of the adhesive drape, cut to the required size, and placed over the tube lines. FIG. 7 illustrates an exemplary microneedle applicator and array used in the integrated chronic wound debridement and healing system. The microneedle applicator and array may be operable to deliver a single injection of an enzymatic debriding agent into and/or within the necrotic tissue present in the wound. As shown in FIG. 7, an elongated, syringe-like debriding agent applicator 710 may be (detachably) attached to a microneedle array 720. The microneedle array 720 may include multiple polymeric microneedles that are arranged substantially in a plurality of rows and a plurality of columns. As an example, the microneedle array 720 may be a cylindrical structure with the microneedles on the lower surface. An alternate angle of a similar microneedle array is shown in FIG. 8A. Notably, due to the three-dimensional arrangement of the microneedles in the microneedle array 720, the debriding agent may be applied to the wound site via the microneedles in a three-dimensional manner, rather than a one- or two-dimensional manner, as is the case in typical existing applications.

Each microneedle in the microneedle array 720 may be of any suitable size and shape, depending on the wound and the desired treatment thereof. In an exemplary case, each microneedle may be 800 μιη in height, 400 μιη in outer diameter, and 200 μιη in inner diameter. The outer diameter of each microneedle can taper from 400 μιη in outer diameter at the base, to 220 μιη in outer diameter at the apex.

Further, the microneedle array 720 may include a fluid reservoir that can hold the debriding agent. The inner shaft of each microneedle may be exposed at the base to the fluid reservoir and may thereby receive the debriding agent. The fluid reservoir may be operable to communicate with the debriding agent applicator 710 via a shaft of the applicator. The debriding agent applicator 710 may include a cylindrical syringe with any suitable volume capacity, depending on the wound and the desired treatment thereof. In an exemplary case, the debriding agent applicator 710 may have a volume capacity of 40 cc. Then, the syringe of the debriding agent applicator 710 may be depressed to deliver the fluidic debriding agent into the chambers of the microneedles included in the microneedle array 720.

FIGS. 8-10 illustrate a variety of debridement accessories that may be used, either alone or in combination with one another, in the integrated chronic wound debridement and healing system. The debridement accessories shown in FIGS. 8-12 may be coupled with the DPWT unit 110, as shown in FIG. 1, thereby forming an integrated, dual purpose DPWT- debridement unit (e.g., integrated chronic wound debridement and healing system 105). However, it should be noted that the debridement accessories disclosed in FIGS. 8-12 may alternatively be used independent of the DPWT unit 110 (e.g., as an independent debriding system), so as to provide a debridement treatment for the patient 100.

FIGS. 8 A and 8B illustrate a foam pad and microneedle array debridement accessory. FIG. 8 A shows a microneedle array 800 (e.g., similar to microneedle array 720) being used independently, while FIG. 8B shows the microneedle array 800 being used in conjunction with a foam pad 810 and the DPWT unit 110, thereby forming the integrated chronic wound debridement and healing system 105, as shown in FIG. 1.

The foam pad 810 may be composed of polyurethane ester and have a substantially uniform thickness. The foam pad 810 may be attached to the microneedle array 800 on the lower surface thereof. Each microneedle in the microneedle array 720 may be of any suitable size and shape, depending on the wound and the desired treatment thereof. In an exemplary case, each microneedle may be 800 μιη in height, 400 μιη in outer diameter, and 200 μιη in inner diameter. The outer diameter of each microneedle can taper from 400 μιη in outer diameter at the base, to 220 μιη in outer diameter at the apex. The inner shaft of each microneedle may be exposed at its base to a fluid reservoir (not shown) that can hold the debriding agent. This fluid reservoir may extend throughout the microneedle array 800 and can have any suitable volume retention capacity, depending on the wound and the desired treatment thereof. In an exemplary case, the fluid reservoir may have a volume retention capacity of 10 cc. The debriding agent may be received from the debriding agent canister 510. That is, the microneedle array 800 and foam pad 810 may be used in conjunction with the debriding agent canister 510.

The microneedle array 800 may include exit pores spaced intermittently throughout the array in order to facilitate wound exudate removal. These pores may empty into another fluid reservoir (not shown) that may be located above the debriding agent fluid reservoir. The exudate reservoir may have a volume retention capacity of 10 cc, for example. The two reservoirs may be coupled to one another (e.g., fused) and attached on the upper surface to the foam pad 810. The foam pad 810, as well as the exudate and debriding agent reservoirs, may be coupled to the tubing set 600. This way, exudate and/or a debriding agent may be transferred back and forth from the microneedle array 800 and the DPWT unit 110.

Accordingly, wound exudate may be removed throughout debridement and DPWT activity.

FIGS. 9A-9C illustrate pH-sensitive bristle arrangement debridement accessories. FIG. 9A shows a schematic representation of pH-responsive debriding bristles, FIG. 9B shows a schematic representation of pH-sensitive hydrogel with debriding bristles engrained therein, and FIG. 9C shows a schematic representation of pH-sensitive hydrogel with flexible debriding bristles. Each illustrative bristle arrangement includes at least multiple debriding bristles 910 mounted to a thin, flexible film 920, which may be porous and mounted to the bottom surface of the foam pad 810. Further, each illustrative bristle arrangement may be used in conjunction with the DPWT unit 110, thereby forming the integrated chronic wound debridement and healing system 105, as shown in FIG. 1. The bristles 910 may be designed to be sharp and stiff enough to cause slow, abrasive removal of necrotic tissue with some shear force (e.g., by patient motion or by an external motor). Specifically, the bristles 910 may be made of a stiff material that can be

microfabricated into a sharp needle-like structure. Many materials may be suitable, including, but not limited to, metal (e.g., stainless steel, titanium, tantalum, nickel), silicon, ceramic (e.g., alumina), or polymer (e.g., photolithographic epoxy, SU-8, PMVE/MA, polycarbonate, PMMA, PLGA, PGA, PLA).

As shown in FIG. 9 A, multiple pH-responsive debriding bristles 910 may be attached to the film 920. The bristles 910 can be made of any suitable pH-responsive material, such as chitosan-based, poly (methacrylic acid)-based, or polyacrylamide -based copolymers, that can cause a bristle-state transition at a pH between that of necrotic tissue (e.g., pH 5.4) and living tissue (e.g., pH 8.4). In particular, the copolymer may be designed to decrease mechanical stiffness at high pH levels (e.g., that of living tissue), such that the otherwise sharp bristles may become flexible so as to not damage living tissue. The reduced stiffness can cause the fibers to bend easily so that they do not impart significant force on the living tissue.

Conversely, the copolymer may be designed to increase mechanical stiffness at low pH levels (e.g., that of necrotic tissue), such that the bristles are capable of debriding the dead tissue. In general, the stiffness change may be related to swelling and dehydration of the polymer. This can be a reversible system in which the bristles can continuously respond to the wound environment and continuously debride only the non- viable tissue. Alternatively, the copolymer may be designed to have bristles that dissolve over regions of healthy tissue, even though this system is irreversible.

As shown in FIG. 9B, multiple debriding bristles 910 may be attached to the film 920 along with a pH-sensitive hydrogel. The hydrogel may be made of any suitable pH- responsive material, such as chitosan-based, poly (methacrylic acid)-based, or polyacrylamide -based, copolymers, that transitions at a pH between that of necrotic tissue (e.g., pH 5.4) and living tissue (e.g., pH 8.4). For example, at a low pH (e.g., that of necrotic tissue), the hydrogel may degrade to reveal the underlying debriding bristles 910 that can then debride the necrotic tissue. Conversely, at a high pH (e.g., that of living tissue), the hydrogel may remain intact to cover the debriding bristles 910, such that they do not come into contact with the tissue. The hydrogel may have a high enough stiffness so as to sufficiently surround the bristles and prevent them from abrading living tissue. This may also be a reversible system in which the system can continuously respond to the wound environment and continuously debride only non- viable tissue.

As shown in FIG. 9C, multiple flexible debriding bristles 910 may be attached to the film 920 along with a pH-sensitive hydrogel. The hydrogel may be made of any suitable pH- responsive material, such as chitosan-based, poly (methacrylic acid)-based, or

polyacrylamide -based, copolymers, that transitions at a pH between that of necrotic tissue (e.g., pH 5.4) and living tissue (e.g., pH 8.4). For example, at a high pH (e.g., that of living tissue), the hydrogel may shrink such that the debriding bristles 910 are no longer supported by the surrounding hydrogel and thus bend toward the film 920. This way, the debriding bristles 910 may not touch the living tissue, or if they do touch, they are not supported enough to provide the necessary pressure to actually remove tissue. Conversely, at a low pH (e.g., that of necrotic tissue), the hydrogel may have a high enough stiffness so as to sufficiently support the debriding bristles 910 around it. This way, the debriding bristles 910 may abrade the necrotic tissue. This may also be a reversible system in which the system can continuously respond to the wound environment and continuously debride only non- viable tissue.

In each of the above illustrative cases, the flexible film 920 may include exit pores spaced intermittently throughout in order to facilitate wound exudate removal. These pores may empty into another fluid reservoir (not shown) that may be located above the debriding agent fluid reservoir and attached on the upper surface to the foam pad 810. This way, wound exudate may be removed throughout debridement and DPWT activity.

FIG. 10 illustrates a foam pad and debriding agent-embedded pH-responsive film debridement accessory. As shown in FIG. 10, the tubing set 600 is coupled to the foam pad 810 (e.g., as shown in FIG. 8B) having a debriding agent-embedded pH-responsive film 1010 attached thereto. The debriding agent-embedded pH-responsive film 1010 may be a pH- sensitive PLGA-chitosan- (or similar) based polymer film layer. The polymer film layer may consist of a pH-sensitive polymer that dissolves at low pH (e.g., that of necrotic tissue), in order to deliver the embedded debriding agent. Thus, in a region of necrotic tissue, the polymer can dissolve (e.g., as shown by the dissolved section 1020), thereby delivering the debriding agent. Conversely, at high pH levels (e.g., a region of living tissue), the polymer can remain intact so that the healthy tissue is not damaged. The pH-responsive film may be embedded with any suitable debriding agent, such as CuraSalt, which is FDA-approved for use on necrotic wounds.

Similar to the above, the foam pad 810 may include exit pores spaced intermittently throughout in order to facilitate wound exudate removal. These pores may empty into another fluid reservoir (not shown) that may be located above the debriding agent fluid reservoir and attached on the upper surface to the foam pad 810. This way, wound exudate may be removed throughout debridement and DPWT activity.

When the integrated chronic wound debridement and healing system 105 is applied to patient 100, it is noted that although the system is designed for use at home, it should preferably be applied by a wound care specialist or nurse. To this point, the specialist should first inspect, and then dress the wound, before applying the system 105. The wound should be thoroughly cleaned at the periphery using standard clinical protocol. Once the periwound has been cleaned and is dry, the wound area should be estimated such that the appropriate size of the debridement accessory and attached foam pad (e.g., "foam pad accessory) can be used. The foam pad accessory should only cover the exposed wound area. The accessory should be carefully placed on the wound, making adjustments based on the patient's pain and discomfort. Once the foam pad accessory is in place, an adhesive drape should be placed over the pad. The drape should be trimmed to cover the foam pad accessory, and an additional 3 cm border on all sides of the pad. Once the adhesive drape is sufficiently secure, securing pads should be applied onto the adhesive drape. These should be secured using medical tape on all edges. Finally, a transparent film should be placed above the previously described dressing, and should extend at least 5-6 cm from all borders. The wound area should be dry before application of the transparent film.

After the wound dressing has been applied as detailed above, the tubing set 600 can be used to connect the DPWT unit 110 to the wound dressing and foam pad accessory.

Pressure settings for both positive and negative pressure may be set on the DPWT unit 110 as required by the particular DPWT unit. The time frequencies for positive and negative pressure may also be set, as per the physician' s discretion. Other setting options may include consistent negative pressure, intermittent negative pressure, and intermittent positive and negative pressure (e.g., as shown in FIG. 3). Also, a new wound exudate canister 410 should be attached to the DPWT unit 110. After filling the debriding agent canister 510 with the appropriate debriding/antimicrobial agent, the canister 510 may be inserted into the DPWT unit 110 (note that using the debriding agent canister 510 may be unnecessary in conjunction with the pH-sensitive bristle arrangement debridement accessory or the foam pad and debriding agent-embedded pH-responsive film debridement accessory). The DPWT unit 110 can then be turned on, and the patient may be sent home for the remainder of therapy. Regarding the exudate canister 410 and the debriding agent canister 510, these canisters should be changed only after the DPWT unit 110 has been turned off. The wound exudate canister 410 should not be reused and should be safely disposed after a single use. A new exudate canister 410 should be replaced immediately. The debriding agent canister 510 should last until the next dressing change is performed (e.g., four to five days). At that time, a new debriding agent canister 510 with the prefilled debriding/antimicrobial agent can be inserted into the DPWT unit 110. Generally, after canister changes, the system can be turned back on. Changes to the therapy (e.g., pressure levels, time frequencies, and the like) should be made based on physician discretion.

Moreover, should the pH-sensitive bristle arrangement debridement accessory (e.g., as shown in FIGS. 9A-9C) and/or the foam pad and debriding agent-embedded pH- responsive film debridement accessory (e.g., as shown in FIG. 10) be used along with the DPWT unit 110, microneedle applicator and array (e.g., as shown in FIG. 7) can be used to first deliver an intra-eschar dosage of debriding agent prior to placing the debridement accessory on the wound. After filling the applicator 710 with a fluidic debriding agent, the microneedle array 720 may be gently introduced into the necrotic tissue of the patient 100. The syringe of the applicator 710 can be depressed to introduce the debriding agent, and the applicator 710 can be removed. Then, the debridement accessory can be applied to patient 100 as originally intended, and the wound can be dressed. Also, when using the pH-sensitive bristle arrangement debridement accessory and/or the foam pad and debriding agent- embedded pH-responsive film debridement accessory, changes to the respective accessories should be performed, e.g., every four to five days. The dressing should be taken down prior to replacing the accessory.

FIG. 11 illustrates an exemplary schematic diagram of a controller operable to perform wound imaging and perfusion measurements. In particular, the controller 1100 is configured to perform a variety of functions, including imaging a wound, calculating the wound area, determining a quantity of necrotic tissue, measuring perfusion in the wound area, uploading data to a cloud database, creating a three-dimensional (3D) rendering of the wound surface, generating advanced statistics relating to the wound image, calculating trends in wound tissue composition over time, and other functions, as describe in further detail below.

The controller 1100 may be part of a mobile device (e.g., smart phone, cellular telephone, tablet, and so forth), and thus the program executed by such device (e.g., as described herein) may be a mobile application. However, the controller 1100 may be part of any other suitable computing device featuring imaging and processing capabilities, including, but not limited to, a personal computer (PC), laptop, digital camera, and so forth, and thus, the program described herein may be executed thereon.

As shown in FIG. 11, the controller 1100 may comprise a network interface 1110, a processor 1120, a memory 1140, and a power supply 1160 (e.g., battery), all of which may be interconnected by a system bus 1150. Note that the power supply 1160 is depicted inside the controller 1100 merely for illustration purposes and may not actually reside "inside" the controller.

The network interface 1110, e.g., transceivers, network adaptors, wireless cards, etc. contain the mechanical, electrical, and/or signaling circuitry for communicating data over links, e.g., wired/physical, wireless, or otherwise, coupled to a remote network, including, for example, a wide area network (WAN), a local area network (LAN), a cellular network, data repository, the cloud, and so forth. The network interface 1110 may be configured to transmit and/or receive data using a variety of different communication protocols, as will be understood by those skilled in the art. The controller 1100 may have multiple different types of network interfaces 1110, e.g., wireless and wired/physical connections, whereby the view herein is merely for illustration.

The memory 1140 comprises a plurality of storage locations that are addressable by the processor 1120, and the network interface 1110 for storing data, including programs, data structures, and the like, associated with the embodiments described herein. The processor 1120 may comprise necessary elements or logic adapted to execute any stored programs and manipulate the data structures 1145. An operating system 1142, portions of which are typically resident in memory 1140 and executed by the processor 1120, functionally organizes the device by, inter alia, invoking operations in support of processes and/or services executing on the device. These processes and/or services may comprise an illustrative "wound measurement process" 1148, as described in greater detail below.

It will be apparent to those skilled in the art that other processor and memory types, including various computer-readable media, may be used to store and execute program instructions pertaining to the techniques described herein. Also, while the description illustrates various processes, it is expressly contemplated that various processes may be embodied as modules configured to operate in accordance with the techniques herein (e.g., according to the functionality of a similar process). Further, while the processes have been shown separately, those skilled in the art will appreciate that processes may be routines or modules within other processes.

FIGS. 12A and 12B illustrate exemplary interfaces of a wound imaging and perfusion measurement application. The wound imaging and perfusion measurement application (e.g., "wound measurement process" 1148) may be a mobile-based application that can be used on a smart phone, tablet, etc. It should be understood that any suitable interface may be used for the wound imaging and perfusion measurement application. Thus, the interfaces illustrated in FIGS. 12A and 12B are shown for demonstration purposes only and should not be treated as limiting the disclosed embodiments.

The application allows a user to acquire an image of a wound 1210 while maintaining calibrated and standardized lighting. The user may then demarcate the boundaries of the wound 1210, and the application may calculate the appropriate 2D wound area 1220. The application may also have depth assessment technology that generates a 3D contour of the wound, allowing for wound volume measurement.

The application can then calculate the area occupied by four tissue types - e.g., necrotic tissue, fibrinous tissue, granulation tissue, and living tissue. This calculation may be performed based on a colorimetric analysis (e.g., a method of determining the concentration of tissue types in a wound with the aid of color reagents) of the wounds through supervoxel analysis (e.g., volumetric segmentation). Thus, based on a frequency-based colorimetric analysis, the application may then generate a histogram 1230 of the various wound types.

Finally, the application may calculate wound perfusion in terms of absolute perfusion units by performing spatial colorimetric analysis using superpixel image segmentation (e.g., partitioning a digital image into multiple segments known as "superpixels"). This technique involves segmenting the wound based on optimal intensity of edges in the image, rather than conventional rectangular pixel segmentation. Therefore, because of the use of superpixel image analysis, the wound may be imaged at a very high resolution, and thus minute changes in tissue color may be amplified (while focusing on a specific frequency) to calculate perfusion directly below the tissue surface and to generate a perfusion map. By adopting a principle similar to Hyperspectral image analysis, a mean value for the overall wound perfusion (e.g., in perfusion units) may then be calculated (e.g., 1240 in FIGS. 12A and 12B). The perfusion map may also highlight areas that are below a threshold perfusion level, which can be predetermined by the physician.

The application may also transfer image data and calculated values to a cloud database that can be accessed by physicians remotely (e.g., via network interface 1110). Repeated wound analyses can also be used to generate a time-based progression of wound healing, using wound area, percentage of necrotic tissue, and perfusion units as the main parameters, for example. Further, the 3D contour map of the wound may be used to design custom wound dressings and debridement accessories that fit the individual characteristics of each wound.

Notably, the application may be used by healthcare professionals and patients alike. For example, healthcare professionals can use the application to order patient-specific wound dressings and objectively assess wound healing. Also, patients can use the application to easily gain a better understanding of their wound - as the image analysis is largely automated - and may be incentivized to take better care of their wounds to hasten wound healing and closure.

The techniques described herein, therefore, provide for wound imaging and debridement. As noted above, the techniques described herein provide for combining debridement and DPWT, which has previously been problematic, and for an effective wound treatment solution that is both continuously operating and capable of being used at home. Moreover, the techniques described herein provide for a reliable, automated wound imaging application, where typical human-based wound inspection causes a significant degree of interpersonal variation, often depending on the skill of the physician. Also, because the application may be designed for use on a mobile device, the application is portable and allows a user to easily perform highly complex calculations, such as 3D wound imaging and wound perfusion measurements.

While there have been shown and described illustrative embodiments that provide for wound imaging and debridement, it is to be understood that various other adaptations and modifications may be made within the spirit and scope of the embodiments herein, with the attainment of some or all of their advantages. For instance, it is expressly contemplated that the components and/or elements described herein with respect to the wound imaging and perfusion measurement application can be implemented as software being stored on a tangible, non-transitory computer-readable medium (e.g., disks/CDs/RAM/EEPROM/etc.) having program instructions executable by a controller, as described above, which may constitute hardware, firmware, or a combination thereof. Moreover, the debridement accessories shown in FIGS. 8-12 may be coupled with the DPWT unit 110 thereby forming an integrated, dual purpose DPWT-debridement unit, or may alternatively be used independent of the DPWT unit 110 (e.g., as an independent debriding system). Accordingly this description is to be taken only by way of example and not to otherwise limit the scope of the embodiments herein. Therefore, it is the object of the appended claims to cover all such variations and modifications as come within the true spirit and scope of the embodiments herein.

Claims

CLAIMS What is claimed is:

1. A system, comprising: a debridement accessory arrangement that debrides necrotic tissue present in a wound of a patient including one or more debridement accessories selected from the group consisting of: a microneedle array including a three-dimensional array of microneedles, the microneedle array being configured to perform three-dimensional debridement of the necrotic tissue by delivering a debriding agent via the microneedles to the necrotic tissue, pH-responsive bristles configured to perform mechanical debridement of the necrotic tissue, wherein the pH-responsive bristles provide greater stiffness when proximate to necrotic tissue and provide less stiffness when proximate to living tissue, and a debriding agent-embedded pH-responsive polymer film configured to perform osmotic debridement of the necrotic tissue, wherein a portion of the debriding agent-embedded pH-responsive polymer film dissolves when proximate to the necrotic tissue and osmotic debridement of the necrotic tissue occurs via the dissolved portion.

2. The system according to claim 1, further comprising: a dual pressure wound therapy (DPWT) unit coupled to the debridement accessory arrangement and configured to intermittently apply positive pressure and negative pressure to the wound of the patient in conjunction with the debriding of the necrotic tissue by the debridement accessory arrangement.

3. A method, comprising: debriding necrotic tissue present in a wound of a patient using a debridement accessory arrangement including one or more debridement accessories selected from the group consisting of: a microneedle array including a three-dimensional array of microneedles, the microneedle array being configured to perform three-dimensional debridement of the necrotic tissue by delivering a debriding agent via the microneedles to the necrotic tissue, pH-responsive bristles configured to perform mechanical debridement of the necrotic tissue, wherein the pH-responsive bristles provide greater stiffness when proximate to necrotic tissue and provide less stiffness when proximate to living tissue, and a debriding agent-embedded pH-responsive polymer film configured to perform osmotic debridement of the necrotic tissue, wherein a portion of the debriding agent-embedded pH-responsive polymer film dissolves when proximate to the necrotic tissue and osmotic debridement of the necrotic tissue occurs via the dissolved portion.

4. The method according to claim 3, further comprising: intermittently applying positive pressure and negative pressure to the wound of the patient using a DPWT unit coupled to the debridement accessory arrangement in conjunction with the debriding of the necrotic tissue by the debridement accessory arrangement.

5. A method, comprising: acquiring an image of a wound of a patient; generating a multi-dimensional image of the wound based on the acquired image; measuring an amount of wound perfusion of the wound based on the acquired image using superpixel image analysis; and generating a frequency-based histogram of the wound perfusion.

6. A non-transitory computer readable medium containing program instructions executable by a controller, the computer readable medium comprising: program instructions that acquire an image of a wound of a patient; program instructions that generate a multi-dimensional image of the wound based on the acquired image; program instructions that measure an amount of wound perfusion of the wound based on the acquired image using superpixel image analysis; and program instructions that generate a frequency-based histogram of the wound perfusion.