WO2024263848A2

WO2024263848A2 - Method for using transepidermal water loss as a clinical biomarker of wound recurrence

Info

Publication number: WO2024263848A2
Application number: PCT/US2024/034918
Authority: WO
Inventors: Chandan K. Sen; Sashwati Roy; Gayle M. Gordillo
Original assignee: Indiana University; Indiana University Bloomington
Current assignee: Indiana University; Indiana University Bloomington
Priority date: 2023-06-23
Filing date: 2024-06-21
Publication date: 2024-12-26
Anticipated expiration: 2025-12-23
Also published as: WO2024263848A3

Abstract

A method for determining functionality of healed wound tissue or skin susceptible to formation of pressure wounds includes measuring transepidermal water loss at a reference location to determine a first transepidermal water loss value, measuring transepidermal water loss within the healed wound tissue or within the skin susceptible to the formation of a pressure wound to determine a second transepidermal water loss value, and comparing the second transepidermal water loss value to the first transepidermal water loss value.

Description

METHOD FOR USING TRANSEPIDERMAL WATER LOSS AS A CLINICAL BIOMARKER OF WOUND RECURRENCE

CROSS-REpFERENCE TO RELATED APPLICATION

[0001] This international patent application claims the benefit of, and priority to, U.S. Provisional Patent Application Ser. No. 63/509,940, filed June 23, 2023, and to U.S. Provisional Patent Application Ser. No. 63/518,244, filed August 08, 2023, the entire disclosures of which are hereby incorporated herein by reference.

TECHNICAL FIELD

[0002] The present disclosure relates generally to methods of determining skin functionality, and more specifically to methods of determining skin functionality using transepidermal water loss values.

BACKGROUND

[0003] Wounds are prone to reopening and/or recurrence. The recurrence of a chronic wound, for example, may be linked to morbidity, amputation, and increased mortality. In addition to negative patient outcomes, economic costs of treating chronic wounds are substantially high. Predicting the onset of recurrence of wounds, and of chronic wounds in particular, may improve diagnosis and allow for suitable intervention strategies to prevent recurrence.

SUMMARY

[0004] The present disclosure may comprise one or more of the features recited in the attached claims, and/or one or more of the following features and combinations thereof.

[0005] In a first aspect, a method for determining functionality of healed wound tissue may comprise measuring transepidermal water loss at a reference location to determine a first transepidermal water loss value, wherein the reference location is i) within about 2 inches to about 4 inches of an edge of the healed wound tissue; or ii) located at the same position as the healed wound tissue on a contralateral limb; measuring transepidermal water loss at the healed wound tissue to determine a second transepidermal water loss value, and comparing the second transepidermal water loss value to the first transepidermal water loss value, wherein the second transepidermal water loss value being at least two times greater than the first transepidermal water loss value is indicative of non-restoration of skin functionality of the healed wound tissue.

[0006] A second aspect includes the features of the first aspect, and wherein the second transepidermal water loss value being less than two times the first transepidermal water loss value may be indicative of restoration of skin functionality of the healed wound tissue.

[0007] A third aspect includes the features of any of the first aspect through the second aspect, and wherein the reference location may be within 3 inches of the edge of the healed wound tissue.

[0008] A fourth aspect includes the features of any of the first aspect through the second aspect, and wherein a plurality of measurements of transepidermal water loss may be determined at the reference location, each of the plurality of measurements may be taken at a different location, each within about 2 inches to about 4 inches of an outer edge perimeter of the healed wound tissue, and wherein the first transepidermal water loss value may be an average of the plurality of measurements.

[0009] A fifth aspect includes the features of the fourth aspect, and wherein the different locations of the plurality of measurements of transepidermal water loss may be equally spaced from one another relative to a perimeter of a circle encompassing the healed wound tissue.

[0010] A sixth aspect includes the features of any of the fourth aspect through the fifth aspect, and wherein the plurality of measurements of transepidermal water loss may include two, three, or four measurements. [0011] A seventh aspect includes the features of any of the first aspect through the second aspect, and wherein a plurality of first measurements of transepidermal water loss may be determined at the reference location, each of the plurality of first measurements may be taken at a different location, each within about 2 inches to about 4 inches of an outer edge perimeter of the healed wound tissue, and wherein the first transepidermal water loss value may be an average of the plurality of first measurements.

[0012] An eighth aspect includes the features of the seventh aspect, and wherein a plurality of second measurements of transepidermal water loss may be determined within the healed wound tissue, each of the plurality of second measurements may be taken at a different location, each interior to an outer edge perimeter of the healed wound tissue, and wherein the second transepidermal water loss value may be an average of the plurality of second measurements.

[0013] A ninth aspect includes the features of the eighth aspect, and wherein the second transepidermal water loss value being less than two times the first transepidermal water loss value may be indicative of restoration of skin functionality of the healed wound tissue.

[0014] A tenth aspect includes the features of the eighth aspect, and wherein the plurality of second measurements of transepidermal water loss may include two, three, or four measurements.

[0015] An eleventh aspect includes the features of any of the first aspect through the sixth aspect, and the method may further comprise measuring a plurality of temperatures at a plurality of locations within the healed wound tissue to determine, based on one or a subset of the plurality of temperatures, one or more locations within the healed wound tissue to measure the transepidermal water loss.

[0016] A twelfth aspect includes the features of the eleventh aspect, and the method may further comprise using a lowest or near lowest one of the plurality of temperatures to determine the one or more locations within the healed wound tissue to measure the transepidermal water loss.

[0017] In a thirteenth aspect, a method of monitoring an area of skin susceptible to formation of pressure wounds for detection of an early stage pressure wound may comprise measuring transepidermal water loss at a reference location to determine a first transepidermal water loss value, wherein the reference location is i) within about 2 inches to about 4 inches of a border of the area of skin; or ii) located at another area of skin contralateral to the area of skin, wherein the another area of skin is not susceptible to the formation of a pressure wound; measuring transepidermal water loss at the area of skin to determine a second transepidermal water loss value, and comparing the second transepidermal water loss value to the first transepidermal water loss value, wherein the second transepidermal water loss value being at least two times greater than the first transepidermal water loss value indicates a risk of the formation of a pressure wound in the area of skin.

[0018] A fourteenth aspect includes the features of the thirteenth aspect, and wherein the reference location may be skin within three inches of the border of the area of skin.

[0019] A fifteenth aspect includes the features of the thirteenth aspect, and wherein a plurality of measurements of transepidermal water loss may be determined at the reference location, each of the plurality of measurements may be taken at a different location, each within about 2 inches to about 4 inches of the border of the area of skin, and wherein the first transepidermal water loss value may be an average of the plurality of measurements.

[0020] A sixteenth aspect includes the features of the fifteenth aspect, and wherein the different locations of the plurality of measurements of transepidermal water loss may be equally spaced from one another relative to a perimeter of a circle encompassing the area of skin. [0021] A seventeenth aspect includes the features of any of the fifteenth aspect through the sixteenth aspect, and wherein the plurality of measurements of transepidermal water loss may include two, three, or four measurements.

[0022] An eighteenth aspect includes the features of any of the thirteenth aspect through the seventeenth aspect, and wherein the second transepidermal water loss value being less than two times the first transepidermal water loss value may be indicative of no risk of formation of a pressure wound in the area of skin.

[0023] A nineteenth aspect includes the features of the thirteenth aspect, and wherein a plurality of first measurements of transepidermal water loss may be determined at the reference location, each of the plurality of first measurements may be taken at a different location, each within about 2 inches to about 4 inches of the border of the area of skin, and wherein the first transepidermal water loss value may be an average of the plurality of first measurements.

[0024] A twentieth aspect includes the features of the nineteenth aspect, and wherein a plurality of second measurements of transepidermal water loss may be determined at the area of skin, each of the plurality of second measurements may be taken at a different location, each interior to the border of the area of skin, and wherein the second transepidermal water loss value may be an average of the plurality of second measurements.

[0025] A twenty-first aspect includes the features of any of the nineteenth aspect through the twentieth aspect, and wherein the second transepidermal water loss value being less than two times the first transepidermal water loss value may be indicative of no risk of formation of a pressure wound in the area of skin.

[0026] A twenty-second aspect includes the features of any of the twentieth aspect through the twenty-first aspect, and wherein the plurality of second measurements of transepidermal water loss may include two, three, or four measurements.

[0027] A twenty-third aspect includes the features of any of the thirteenth aspect through the eighteenth aspect, and the method may further comprise measuring a plurality of temperatures at a plurality of locations within the area of skin to determine, based on one or a subset of the plurality of temperatures, one or more locations within the area of skin to measure the transepidermal water loss.

[0028] A twenty-fourth aspect includes the features of the twenty-third aspect, and the method may further comprise using a lowest or near lowest one of the plurality of temperatures to determine the one or more locations within the area of skin to measure the transepidermal water loss.

[0029] In a twenty-fifth aspect, a method for monitoring skin may comprise measuring transepidermal water loss at a reference location to determine a first transepidermal water loss value, wherein the reference location is i) within about 2 inches to about 4 inches of an edge of a monitored area of skin; or ii) located at the same position as the monitored area of skin on a contralateral limb; measuring transepidermal water loss at the monitored area of skin to determine a second transepidermal water loss value, and comparing the second transepidermal water loss value to the first transepidermal water loss value, wherein the second transepidermal water loss value being at least two times greater than the first transepidermal water loss value indicates a risk of damage to the monitored area of skin.

[0030] A twenty-sixth aspect includes the features of the twenty-fifth aspect, and wherein the monitored area of skin may be healed wound tissue. [0031] A twenty-seventh aspect includes the features of the twenty-sixth aspect, and wherein the second transepidermal water loss value being greater than two times the first transepidermal water loss value may be indicative of nonrestoration of skin functionality of the healed wound tissue, and wherein the second transepidermal water loss value being less than two times the first transepidermal water loss value may be indicative of restoration of skin functionality of the healed wound tissue.

[0032] A twenty-eighth aspect includes the features of the twenty-fifth aspect, and wherein the monitored area of skin may be skin susceptible to the formation of pressure wounds.

[0033] A twenty-ninth aspect includes the features the twenty-eighth aspect, and wherein the second transepidermal water loss value being greater than two times the first transepidermal water loss value may be indicative of a risk of formation of a pressure wound at the monitored area of skin, and wherein the second transepidermal water loss value being less than two times the first transepidermal water loss value may be indicative of no risk of formation of a pressure wound at the monitored area of skin.

[0034] A thirtieth aspect includes the features of any of the twenty-fifth aspect through the twenty-ninth aspect, and wherein the reference location may be within 3 inches of the edge of the monitored area of skin.

[0035] A thirty-first aspect includes the features of any of the twenty-fifth aspect through the twenty-ninth aspect, and wherein a plurality of measurements of transepidermal water loss may be determined at the reference location, each of the plurality of measurements may be taken at a different location, each within about 2 inches to about 4 inches of an outer edge perimeter of the monitored area of skin, and wherein the first transepidermal water loss value may be an average of the plurality of measurements.

[0036] A thirty-second aspect includes the features of the thirty-first aspect, and wherein the different locations of the plurality of measurements of transepidermal water loss may be equally spaced from one another relative to a perimeter of a circle encompassing the monitored area of skin.

[0037] A thirty-third aspect includes the features of any of the thirty-first aspect through the thirty-second aspect, and wherein the plurality of measurements of transepidermal water loss may include two, three, or four measurements.

[0038] A thirty-fourth aspect includes the features of any of the twenty-fifth aspect through the twenty-ninth aspect, and wherein a plurality of first measurements of transepidermal water loss may be determined at the reference location, each of the plurality of first measurements may be taken at a different location, each within about 2 inches to about 4 inches of an outer edge perimeter of the monitored area of skin, and wherein the first transepidermal water loss value may be an average of the plurality of first measurements.

[0039] A thirty-fifth aspect includes the features of the thirty-fourth aspect, and wherein a plurality of second measurements of transepidermal water loss may be determined at the monitored area of skin, each of the plurality of second measurements may be taken at a different location, each interior to the outer edge perimeter of the monitored area of skin, and wherein the second transepidermal water loss value may be an average of the plurality of second measurements.

[0040] A thirty-sixth aspect includes the features of the thirty-fifth aspect, and wherein the plurality of second measurements of transepidermal water loss may include two, three, or four measurements.

[0041] A thirty-seventh aspect includes the features of any of the twentyfifth aspect through the twenty-ninth aspect, and the method may further comprise measuring a plurality of temperatures at a plurality of locations within the monitored area of skin to determine, based on one or a subset of the plurality of temperatures, one or more locations within the monitored area of skin to measure the transepidermal water loss.

[0042] A thirty-eighth aspect includes the features of the thirty-seventh aspect, and the method may further comprise using a lowest or near lowest one of the plurality of temperatures to determine the one or more locations within the monitored area of skin to measure the transepidermal water loss. [0043] In a thirty-ninth aspect, a method of monitoring an area of skin susceptible to formation of pressure wounds for detection of an early stage pressure wound may comprise (i) measuring a plurality of temperatures at a plurality of locations within the area of skin, (ii) determining a lowest or near lowest one of the plurality of temperatures, (iii) measuring transepidermal water loss at the location within the area of susceptible skin having the lowest or near lowest one of the plurality of temperatures to determine a transepidermal water loss value, (iv) waiting a specified time period, (v) repeating (i), (ii), and (iii) after waiting the specified time period, and (vi) comparing the transepidermal water loss values, wherein a generally increasing transepidermal water loss value over time indicates a risk of formation of a pressure wound at the area of skin.

[0044] A fortieth aspect includes the features of the thirty-ninth aspect, and wherein the lowest or near lowest one of the plurality of temperatures is the lowest temperature of the plurality of temperatures.

[0045] A forty-first aspect includes the features of any of the thirty-ninth aspect through the fortieth aspect, and wherein a generally decreasing or a generally steady transepidermal water loss value over time may indicate no risk of formation of a pressure wound at the area of skin.

[0046] In a forty-second aspect, a diagnostic system for monitoring an area of monitored skin may comprise a measuring device configured to measure transepidermal water loss; a processor; and a memory having instructions stored therein executable by the processor to cause the processor to (a) determine a first transepidermal water loss value based, at least in part, on a measured transepidermal water loss at a reference location of skin, (b) determine a second transepidermal water loss value based, at least in part, on a measured transepidermal water loss within the area of monitored skin, and (c) compare the second transepidermal water loss value to the first transepidermal water loss value, wherein the second transepidermal water loss value being at least two times greater than the first transepidermal water loss value indicates a risk of damage to the area of monitored skin.

[0047] A forty-third aspect includes the features of the forty- second aspect, and wherein the reference location may be i) within about 2 inches to about 4 inches of an outer edge perimeter of the area of monitored skin; or ii) located at the same position as the area of monitored skin on a contralateral limb.

[0048] A forty-fourth aspect includes the features of any of the forty- second aspect through the forty-third aspect, and wherein the area of monitored skin may be healed wound tissue.

[0049] A forty-fifth aspect includes the features of the forty-fourth aspect, and wherein the second transepidermal water loss value being greater than two times the first transepidermal water loss value may be indicative of nonrestoration of skin functionality of the healed wound tissue, and wherein the second transepidermal water loss value being less than two times the first transepidermal water loss value may be indicative of restoration of skin functionality of the healed wound tissue.

[0050] A forty-sixth aspect includes the features of any of the forty-second aspect through the forty-third aspect, and wherein the area of monitored skin may be skin susceptible to formation of a pressure wound.

[0051] A forty-seventh aspect includes the features of the forty-sixth aspect, and wherein the second transepidermal water loss value being greater than two times the first transepidermal water loss value may be indicative of a risk of formation of a pressure wound at the area of monitored skin, and wherein the second transepidermal water loss value being less than two times the first transepidermal water loss value may be indicative of no risk of formation of a pressure wound at the area of monitored skin.

[0052] These and other features of the present disclosure will become more apparent from the following description of the illustrative embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] FIG. 1 is a diagrammatic view of a diagnostic system configured to determine the functionality of healed wound tissue, the diagnostic system includes a measuring device to measure transepidermal water loss and a processor in communication with the measuring device to compare different transepidermal water loss values;

[0054] FIG. 2 is a flow diagram of a method for determining the functionality of the healed wound tissue using the diagnostic system of FIG. 1 ;

[0055] FIG. 3 is a flow diagram of a method for monitoring skin susceptible to formation of pressure wounds to detect early stage pressure wounds using the diagnostic system of FIG. 1 ;

[0056] FIG. 4 is a flow diagram of a method for determining the functionality of the healed wound tissue using the diagnostic system of FIG. 1 ; and

[0057] FIG. 5 is a flow diagram of a method for monitoring skin susceptible to formation of pressure wounds to detect early stage pressure wounds using the diagnostic system of FIG. 1 .

DETAILED DESCRIPTION OF THE DRAWINGS

[0058] For the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to a number of illustrative embodiments illustrated in the drawings and specific language will be used to describe the same.

[0059] For purposes of this disclosure, the term of “healed wound tissue" or “repaired wound” or “closed wound” shall be understood to mean a wound which has previously broken the skin but which subsequently healed so as to visually appear to be covered with intact skin without any visible openings. The term “chronic wound” shall be understood to mean a wound which has previously broken the skin, and the subsequent healing of which has not progressed through a normal, orderly, and timely sequence of repair.

[0060] Transepidermal water loss is indicative of skin barrier function and functionality of healed wound tissue. High transepidermal water loss is the loss of water from inside of a body, above physiological limits, due to compromised barrier function of the skin. Measurements of transepidermal water loss may be used to identify skin barrier function, and thus, the functionality of healed wound tissue.

[0061] If transepidermal water loss is relatively low, the healed wound tissue has restoration of skin functionality. A relatively high transepidermal water loss corresponds to a compromised skin barrier. Thus, if healed wound tissue has a relatively high transepidermal water loss, the healed wound tissue has poor functionality, which may lead to allergens, pathogens, and irritants, for example, passing through the compromised skin barrier of the healed wound tissue.

[0062] A diagnostic system 10 is used to determine if healed wound tissue 12 has a compromised skin barrier, and thus, poor functionality. The diagnostic system 10 includes a measuring device 14 configured to measure transepidermal water loss. In some embodiments, other measuring devices may be used. The measuring device 14 is in communication with a processor 16. The processor 16 is in communication with a monitor 18, a keypad 20, and/or a database 22 as shown in FIG. 1.

[0063] A method 110 for determining the functionality of healed wound tissue 12 using the diagnostic system 10 is provided and shown in FIG. 2. The method 110 may be used as a diagnostic to determine if a healed wound is at risk for recurrence. The healed wound tissue 12 may also be referred to as a monitored area of skin. The method 110 includes step 112 of measuring transepidermal water loss at a reference location 24 to determine a first transepidermal water loss value. The first transepidermal water loss value may be referred to as a reference value. The reference location 24 is normal skin, uninjured skin, or resting skin. The measuring device 14 measures transepidermal water loss for the reference location 24 as shown in FIG. 1 . The first transepidermal water loss as measured by the measuring device 14 is transmitted to the processor 16 and may be displayed on the monitor 18. The processor 16 determines the first transepidermal water loss value based, at least in part, on the first transepidermal water loss measured by the measuring device 14. The first transepidermal water loss and the first transepidermal water loss value are stored in a memory 26 of the processor 16.

[0064] In some embodiments, step 112 may include measuring transepidermal water loss at one or more locations of the reference location 24. In other words, step 112 may include measuring a plurality of first measurements of transepidermal water loss at the reference location 24. In one example embodiment, a single transepidermal water loss may be measured at step 112 at the reference location 24. In another example embodiment, a plurality of first measurements of transepidermal water loss may be taken at the reference location 24. In some such embodiments, the plurality of first measurements may include randomly or uniformly scanning the reference location 24. Each of the plurality of first measurements may be taken at different locations surrounding the healed wound tissue 12. For example, each of the plurality of first measurements are taken within about 2 inches to about 4 inches of an edge of the healed wound tissue 12. In some embodiments, each of the plurality of first measurements of transepidermal water loss are taken at positions equally spaced from one another relative to the edge of a circle encompassing the healed wound tissue 12. For example, different measurements may be taken 360 degrees around the edge of the circle encompassing the healed wound tissue 12. In some embodiments, multiple sets of measurements surrounding the edge of the circle encompassing the healed wound tissue 12 are taken, each extending further radially away from the edge of the healed wound tissue 12. In this embodiment, a scan of the reference location 24 is taken.

[0065] In some embodiments, the first transepidermal water loss value is an average of the plurality of first measurements of the first transepidermal water loss. Any number of measurements may be measured to determine the first transepidermal water loss value, such as two measurements, three measurements, or four measurements. It will be understood that the term “average,” as used above, may be or include one or more conventional mathematical averaging techniques including, but not limited to, an algebraic average, a running average, a weighted average, a statistical average, or the like. In some embodiments, the first transepidermal water loss valve may be the highest, lowest, middle, or other single value of the plurality of measurements. [0066] Typical transepidermal water loss values for normal skin, uninjured skin, or resting skin may range from about 4 g/m² per hour to about 12 g/m² per hour, including any specific range or number comprised therein. It will be understood that transepidermal water loss is dependent on the skin, the location of the skin on the body, and the patient. Thus, transepidermal water loss may be different for each patient and for different locations on the body of each patient. [0067] The method 110 includes step 114 of measuring transepidermal water loss within the healed wound tissue 12 to determine a second transepidermal water loss value. In some embodiments, the healed wound tissue 12 is a repaired wound, a closed wound, or a repaired chronic wound. Repaired wounds, as defined above, may appear closed such that the wounds appear to have intact skin with no visible openings.

[0068] The measuring device 14 measures transepidermal water loss for the healed wound tissue 12 as suggested in FIG. 1 . The second transepidermal water loss is transmitted to the processor 16 and may be displayed on the monitor 18. The processor 16 determines the second transepidermal water loss value based, at least in part, on the second transepidermal water loss as measured by the measuring device 14. The second transepidermal water loss and the second transepidermal water loss value are stored in the memory 26 of the processor 16.

[0069] In some instances, a visual inspection of the healed wound tissue 12 may reveal one or more portions or locations which appear to be at least partially open or otherwise less healed as compared to other portions of the healed wound tissue 12. In some such embodiments, step 114 may include measuring transepidermal water loss at one or more locations of the open or less healed portion(s) of the healed wound tissue 12. In other words, step 114 may include measuring a plurality of second measurements of transepidermal water loss at the healed wound tissue 12. In one example embodiment, a single transepidermal water loss may be measured at step 114 for at least one open or less healed portion(s) of the healed wound tissue 12. In another example embodiment, a plurality of second measurements of transepidermal water loss may be taken at the at least one open or less healed portion(s) of the healed wound tissue 12. In some such embodiments, the plurality of second measurements may include randomly or uniformly scanning the at least one open or less healed portion(s) of the healed wound tissue 12.

[0070] In some embodiments, visual inspection of the healed wound tissue 12 may not reveal one or more portions or locations which appear to be at least partially open or otherwise less healed as compared to other portions of the healed wound tissue 12, and the healed wound tissue 12 may accordingly appear substantially uniformly healed (or substantially uniformly partially healed). In some such embodiments, step 114 of the method 110 may include determining a plurality of second measurements of transepidermal water loss at a plurality of locations of the healed wound tissue 12 and of the healed wound tissue 12 as a whole. Each of the plurality of second measurements are illustratively taken at different locations of the healed wound tissue 12. For example, each of the plurality of second measurements are taken interior to the edge (i.e. , a perimeter) of the healed wound tissue 12. In some embodiments, each of the plurality of second measurements of transepidermal water loss are taken at positions interior to the edge of the healed wound tissue 12 equally spaced from one another relative to the edge of the healed wound tissue 12. For example, different measurements may be taken 360 degrees interior to the edge of a circle encompassing the healed wound tissue 12. In some embodiments, each of the plurality of second measurements includes a measurement at a center point of the healed wound tissue 12, followed by measurements surrounding the center point of the healed wound tissue 12. In some embodiments, multiple sets of measurements surrounding the center point may be taken, each extending further radially away from the center point toward the edge of the healed wound tissue 12. In this embodiment, a scan of the healed wound tissue 12 is taken to determine a site or sites of the healed wound tissue 12 most at risk of recurrence and reopening. In some embodiments, the plurality of second measurements may include randomly or uniformly scanning the healed wound tissue 12.

[0071] In some embodiments, the second transepidermal water loss value may be an average of the plurality of second measurements. Any number of measurements may be measured and used to determine the second transepidermal water loss value, such as two measurements, three measurements, or four measurements. It will be understood that the term “averaging,” as used above, may be or include one or more conventional mathematical averaging techniques including, but not limited to, an algebraic average, a running average, a weighted average, a statistical average, or the like. In some embodiments, the second transepidermal water loss valve may be the highest, lowest, middle, or other single value of the plurality of measurements.

[0072] In step 116, the second transepidermal water loss value is compared to the first transepidermal water loss value. The method 110 includes decision step 118 during which the processor 16, using instructions stored in the memory 26, determines if the second transepidermal water loss value is at least two times greater than the first transepidermal water loss value. In some embodiments, the processor 16 determines if the second transepidermal water loss value is at least three times greater than the first transepidermal water loss value. Generally, the second transepidermal water loss value is compared to a multiple, integer, or real value of the first transepidermal water loss value.

[0073] In some embodiments, the first transepidermal water loss value is statistically determined using transepidermal water loss measurements for the reference location 24 and the database 22. In alternate embodiments, the first transepidermal water loss value may be a static value stored in the memory 26 and/or in the database 22.

[0074] If the second transepidermal water loss value is less than two times the first transepidermal water loss value as determined in decision step 118, then the second transepidermal water loss value is deemed low in step 122, indicating that skin functionality of the healed wound tissue 12 has been restored. In step 122, the processor 16 transmits a first indicator to the monitor 18 for display. The first indicator suggests that the healed wound tissue 12 is not at risk, or is at a reduced risk, for reopening and recurrence because the skin barrier function at the site of wound repair is not compromised. In other words, the first indicator suggests that the healed wound tissue 12 is adequately healed and/or is acceptably healed, taking into account characteristics of the patient.

[0075] If the second transepidermal water loss value is at least two times greater than the first transepidermal water loss value, then the second transepidermal water loss value is deemed high in step 120, indicating that the healed wound tissue 12 has poor functionality. In other words, the second transepidermal water loss value being at least two times greater than the first transepidermal water loss value is indicative of non-restoration of skin functionality of the healed wound tissue 12. The high second transepidermal water loss value is indicative of inadequate and/or deficient wound closure and may predict a risk of recurrence. The indication of the high second transepidermal water loss value allows a physician to prepare suitable intervention strategies aimed at restoring the skin functionality, and if warranted, to prevent recurrence of the chronic wound.

[0076] In step 120, the processor 16 illustratively transmits a second indicator to the monitor 18 for display. The second indicator is different than the first indicator. The second indicator suggests that the healed wound tissue 12 is at risk for reopening and recurrence, and thus, has a compromised skin barrier function. In other words, the second indicator suggests that the healed wound tissue 12 is inadequately healed and/or is unacceptably healed, taking into account characteristics of the patient. In any case, the processor 16 illustratively stores the first and second transepidermal water loss values and the first or second indicator in the memory 26 and/or database 22 along with corresponding patient identification information.

[0077] In some embodiments, the reference location 24 is an area of skin adjacent the healed wound tissue 12 as suggested in FIG. 1 . For example, the reference location 24 is within about 2 inches to about 4 inches of the edge of the healed wound tissue 12. In the illustrative embodiment, the reference location 24 is within 3 inches of the edge of the healed wound tissue 12. In some embodiments, the reference location 24 is an area of skin located at the same position as the healed wound tissue 12 on a contralateral limb.

[0078] The reference location 24 and the healed wound tissue 12 are shown illustratively on a leg of the patient in FIG. 1 . However, the reference location 24 and the healed wound tissue 12 may be located anywhere on the body of the patient.

[0079] Methods of measuring transepidermal water loss are known by those of ordinary skill in the art. Any known method of measuring transepidermal water loss may be used. Various commercially available instruments may be used to measure transepidermal water loss values including, but not limited to, DermaLab® Combo by Cortex Technology, Vapometer® by Delfin Technologies, and the Tewameter® by Enviroderm, among others.

[0080] In some embodiments, the diagnostic system 10 may include one or more sensors 15 configured to produce one or more sensor signals which may be used by the processor 16 to compute or modify the measured transepidermal water losses or the first and the second transepidermal water loss values. The sensor(s) 15, in embodiments which include it/them, will generally be configured to produce signals corresponding to patient and/or environmental conditions which may have a bearing on the transepidermal water losses measured with the measuring device 14. Examples of such one or more sensor(s) 15 may include, but are not limited to, one or more sensors configured to measure and produce sensor signals corresponding to absolute or relative humidity of the environment (i.e. , air), the body temperature of the patient, the skin surface temperature of the patient, the perspiration level or activity of the patient, and the like. Alternatively or additionally, the processor 16 may be configured to compute or modify the first and second transepidermal water loss values based on patient information, e.g., entered by the patient or a health care professional via the keypad 20 or other input device. Example patient information may include, but is not limited to, patient age, ethnicity, level of pre-existing skin damage, e.g., ultraviolet light damage, existence of tattoos in or under the healed wound tissue 12, or the like. [0081] In some embodiments, as briefly described above, signals produced by the one or more sensors 15 and/or the patient information may be used in the method 110 to determine and/or modify the first transepidermal water loss value and/or the second transepidermal water loss value.

[0082] The keypad 20 is in communication with the processor 16 as shown in FIG. 1. The health care professional can, for example, input notes regarding the patient, the healed wound tissue 12, and/or the reference location(s) 24. The notes can be stored in addition to the values and indicators in the memory 26 and/or the database 22.

[0083] Another method 210 in accordance with the present disclosure is provided and shown in FIG. 3. The method 210 is substantially similar to the method 110. Accordingly, similar reference numbers in the 200 series indicate similar method steps that are common between the method 110 and the method 210. The description of the method 110 is incorporated by reference to apply to the method 210, except in instances when it conflicts with the specific description of the method 210.

[0084] The method 210 is provided for monitoring an area of skin susceptible to a formation of a pressure wound(s) and detecting an early stage pressure wound using the diagnostic system 10. The method 210 may be used as a diagnostic to determine if an early stage pressure wound is forming. The susceptible skin is an area of skin that is experiencing pressure, for example, due to the resting position of the patient in a bed. The susceptible skin 12 may also be referred to as a monitored area of skin.

[0085] The method 210 includes step 212 of measuring transepidermal water loss at a reference location 24 to determine a first transepidermal water loss value. In some embodiments, the reference location 24 is within about 2 inches to about 4 inches of a border of the area of susceptible skin 12. In the illustrative embodiment, the reference location 24 is within 3 inches of the border of the area of susceptible skin 12. In some embodiments, the reference location 24 is located at skin contralateral to the area of susceptible skin 12. In such an embodiment, the reference location 24 at the contralateral skin is not susceptible to the formation of a pressure wound.

[0086] The measuring device 14 measures transepidermal water loss for the reference location 24. The first transepidermal water loss as measured by the measuring device 14 is transmitted to the processor 16 and may be displayed on the monitor 18. The processor 16 determines the first transepidermal water loss value based, at least in part, on the first transepidermal water loss measured by the measuring device 14. The first transepidermal water loss and the first transepidermal water loss value are stored in a memory 26 of the processor 16. [0087] In some embodiments, step 212 may include measuring transepidermal water loss at one or more locations of the reference location 24. In one example embodiment, a single transepidermal water loss may be measured at step 212 at the reference location 24. In another example embodiment, a plurality of first measurements of transepidermal water loss may be taken at the reference location 24. In some such embodiments, the plurality of first measurements may include randomly or uniformly scanning the reference location 24. Each of the plurality of first measurements may be taken at different locations surrounding the area of susceptible skin 12. For example, each of the plurality of measurements are taken within about 2 inches to about 4 inches of the border of the area of susceptible skin 12. In some embodiments, each of the plurality of first measurements of transepidermal water loss are taken at positions equally spaced from one another relative to the border of the area of susceptible skin 12. For example, different measurements may be taken 360 degrees around the border of the area of susceptible skin 12. In some embodiments, multiple sets of measurements surrounding the border of the area of susceptible skin 12 are taken, each extending further radially away from the border of the area of susceptible skin 12. In this embodiment, a scan of the reference location 24 is taken.

[0088] In some embodiments, the first transepidermal water loss value is an average of the plurality of first measurements of the first transepidermal water loss. Any number of measurements may be measured to determine the first transepidermal water loss value, such as two measurements, three measurements, or four measurements. It will be understood that the term “average,” as used above, may be or include one or more conventional mathematical averaging techniques including, but not limited to, an algebraic average, a running average, a weighted average, a statistical average, or the like. In some embodiments, the first transepidermal water loss valve may be the highest, lowest, middle, or other single value of the plurality of measurements. [0089] The method 210 includes step 214 of measuring transepidermal water loss within the area of susceptible skin 12 to determine a second transepidermal water loss value. The measuring device 14 measures transepidermal water loss for the area of susceptible skin 12. The second transepidermal water loss is transmitted to the processor 16 and may be displayed on the monitor 18. The processor 16 determines the second transepidermal water loss value based, at least in part, on the second transepidermal water loss as measured by the measuring device 14. The second transepidermal water loss and the second transepidermal water loss value are stored in the memory 26 of the processor 16.

[0090] In some embodiments, step 214 of the method 210 may include determining a plurality of second measurements of transepidermal water loss within the area of susceptible skin 12. Each of the plurality of second measurements are taken at different locations within the area of susceptible skin 12. For example, each of the plurality of second measurements are taken interior to the border of the area of susceptible skin 12. In some embodiments, each of the plurality of second measurements of transepidermal water loss are taken at positions interior to the border of the area of susceptible skin 12 equally spaced from one another relative to the border (i.e. , perimeter) of the area of susceptible skin 12. For example, different measurements may be taken 360 degrees interior to the border of a circle encompassing the area of susceptible skin 12. In some embodiments, each of the plurality of second measurements includes a measurement at a center point of the area of susceptible skin 12, followed by measurements surrounding the center point of the area of susceptible skin 12. In some embodiments, multiple sets of measurements surrounding the center point may be taken each extending further radially away from the center point. In this embodiment, a scan of the area of susceptible skin 12 is taken to determine a site of the area of susceptible skin 12 most at risk for developing a pressure wound. In some embodiments, the plurality of second measurements may include randomly or uniformly scanning the area of susceptible skin 12.

[0091] In some embodiments, the second transepidermal water loss value is an average of the plurality of second measurements. Any number of measurements may be measured to determine the second transepidermal water loss value, such as two measurements, three measurements, or four measurements. It will be understood that the term “average,” as used in this paragraph, may be or include one or more conventional mathematical averaging techniques including, but not limited to, an algebraic average, a running average, a weighted average, a statistical average, or the like.

[0092] The method 210 includes step 216 of comparing the second transepidermal water loss value to the first transepidermal water loss value. The method 210 includes decision step 218 during which the processor 16, using instructions stored in the memory 26, determines if the second transepidermal water loss value is at least two times greater than the first transepidermal water loss value. In some embodiments, the processor 16 determines if the second transepidermal water loss value is at least three times greater than the first transepidermal water loss value. Generally, the second transepidermal water loss value is compared to a multiple, integer, or real value of the first transepidermal water loss value.

[0093] If the second transepidermal water loss value is less than two times the first transepidermal water loss value as determined in decision step 218, then the second transepidermal water loss value is deemed low in step 222, indicating that there is a minimal risk of the formation of a pressure wound at the susceptible skin 12. In some embodiments, if the second transepidermal water loss value is less than two times the first transepidermal water loss value, then there is not a risk of the formation of a pressure wound. In step 222, the processor 16 transmits a first indicator to the monitor 18 for display. The first indicator suggests that the susceptible skin 12 is not at risk, or is at a reduced risk, for the formation of a pressure wound.

[0094] If the second transepidermal water loss value is at least two times greater than the first transepidermal water loss value, then the second transepidermal water loss value is deemed high in step 222, indicating that there is an increased risk of the formation of a pressure wound at the susceptible skin 12. some embodiments, if the second transepidermal water loss value is greater than two times the first transepidermal water loss value, then there is a risk of the formation of a pressure wound. The indication of the high second transepidermal water loss value allows a physician to prepare suitable intervention strategies aimed at restoring the skin functionality, and if warranted, to prevent the formation of the pressure wound.

[0095] In step 220, the processor 16 illustratively transmits a second indicator to the monitor 18 for display. The second indicator is different than the first indicator. The second indicator suggests that the susceptible skin 12 is at risk for forming a pressure wound. In any case, the processor 16 illustratively stores the first and second transepidermal water loss values and the first or second indicator in the memory 26 and/or database 22 along with corresponding patient identification information.

[0096] In accordance with one embodiment, the use of thermographic imaging of skin tissue can be combined with transepidermal water loss to determine the functionality of healed wound tissue and/or to monitor skin susceptible to the formation of pressure wounds. The thermographic imager may be a handheld device or any thermographic imager known to those skilled in the art. Skin locations associated with high transepidermal water loss will have a relatively lower temperature. Thus, identifying regions of skin having lower temperature can be used to guide precise placement of the transepidermal water loss measuring probe for measurement to confirm skin sites having low functionality. In accordance with one embodiment, a first step may include imaging an area at risk (e.g., a closed wound or an area susceptible to a pressure wound) with a thermographic imager, checking the temperature profile to identify a relative cold spot, and then using the transepidermal water loss measuring probe to take measurements at that relative cold spot or in proximity to the identified relative cold spot. If no relative cold spots are detected in the first step, then the center of the former wound (now closed) may serve as the spot for transepidermal water loss measurement, or alternatively, the center of the region susceptible to a pressure wound.

[0097] Rising transepidermal water loss at a site affected by pressure over time predicts pressure ulceration. Accordingly, in one embodiment, the use of thermographic imaging of skin tissue can be combined with transepidermal water loss to predict and mediate the risk of pressure ulcers. Such sites may be targeted for thermographic imaging to enable precise placement of the transepidermal water loss measuring probe for measurement. The transepidermal water loss measurement may be performed twice a week for four weeks. If the transepidermal water loss value rises over that period of measurement, it may predict a pressure ulcer at the location before it is visualized. Identification of skin progression towards pressure ulcer formation may allow for intervention (e.g., offloading) to relieve the pressure to prevent the pressure ulcer prior to visible damage.

[0098] Another method 310 for determining the functionality of healed wound tissue 12 using the diagnostic system 10 in accordance with the present disclosure is provided and shown in FIG. 4. The method 310 may be used as a diagnostic to determine if a healed wound is at risk for recurrence. Many of the steps of the method 310 are substantially similar to those of the method 110 and the method 210. The description of the method 110 and the method 210 are incorporated by reference to apply to the method 310, except in instances when it conflicts with the specific description of the method 310. [0099] In some embodiments, the diagnostic system 10 includes a thermographic imager 19 to measure temperature as shown in FIG. 1. The thermographic imager 19 is conventional and may be or include a hand-held or other imaging apparatus or device suitable for measuring temperature at various locations, or of an entirety of, a healed chronic wound. In some embodiments, other measuring devices may be used to measure temperature. The thermographic imager 19 is in communication with the processor 16.

[00100] The method 310 includes step 312 of measuring transepidermal water loss at the reference location 24 to determine a first transepidermal water loss value. The first transepidermal water loss value may be referred to as a reference value. The reference location 24 is normal skin, uninjured skin, or resting skin. The measuring device 14 measures transepidermal water loss for the reference location 24. The first transepidermal water loss is transmitted to the processor 16 and may be displayed on the monitor 18. The processor 16 determines the first transepidermal water loss value based, at least in part, on the first transepidermal water loss measured by the measuring device 14. The first transepidermal water loss and the first transepidermal water loss value are stored in a memory 26 of the processor 16.

[00101] In some embodiments, step 312 may include measuring transepidermal water loss at one or more locations of the reference location 24. In one example embodiment, a single transepidermal water loss may be measured at step 312 at the reference location 24. In another example embodiment, a plurality of first measurements of transepidermal water loss may be taken at the reference location 24. In some such embodiments, the plurality of first measurements may include randomly or uniformly scanning the reference location 24. Each of the plurality of first measurements may be taken at different locations surrounding the healed wound tissue 12. For example, each of the plurality of first measurements are taken within about 2 inches to about 4 inches of an edge of the healed wound tissue 12. In some embodiments, each of the plurality of first measurements of transepidermal water loss are taken at positions equally spaced from one another relative to the edge of a circle encompassing the healed wound tissue 12. For example, different measurements may be taken 360 degrees around the edge of the circle encompassing the healed wound tissue 12. In some embodiments, multiple sets of measurements surrounding the edge of the circle encompassing the healed wound tissue 12 are taken, each extending further radially away from the edge of the healed wound tissue 12. In this embodiment, a scan of the reference location 24 is taken.

[00102] In some embodiments, the first transepidermal water loss value is an average of the plurality of first measurements of the first transepidermal water loss. Any number of measurements may be measured to determine the first transepidermal water loss value, such as two measurements, three measurements, or four measurements. It will be understood that the term “average,” as used above, may be or include one or more conventional mathematical averaging techniques including, but not limited to, an algebraic average, a running average, a weighted average, a statistical average, or the like. In some embodiments, the first transepidermal water loss valve may be the highest, lowest, middle, or other single value of the plurality of first measurements.

[00103] The method 310 includes step 314 of measuring a plurality of temperatures of various locations within the healed wound tissue 12 using the thermographic imager 19. In some embodiments, thermographic imaging of an entirety of the healed wound tissue 12 is performed. In this embodiment, a scan of temperatures of the healed wound tissue 12 is performed. The plurality of temperature measurements and the location within the healed wound tissue 12 corresponding to each measured temperature are transmitted to the processor 16 and may be displayed on the monitor 18. The plurality of temperature measurements and the locations at which each was measured are stored in the memory 26 of the processor 16. [00104] Each of the plurality of temperature measurements are illustratively taken at different locations of the healed wound tissue 12. For example, each of the plurality of temperature measurements are taken interior to the edge (i.e. , a perimeter) of the healed wound tissue 12. In some embodiments, each of the plurality of temperature measurements are taken at positions interior to the edge of the healed wound tissue 12 equally spaced from one another relative to the edge of the healed wound tissue 12. For example, different temperature measurements may be taken 360 degrees interior to the edge of a circle encompassing the healed wound tissue 12. In some embodiments, each of the plurality of temperature measurements includes a temperature measurement at a center point of the healed wound tissue 12, followed by temperature measurements surrounding the center point of the healed wound tissue 12. In some embodiments, multiple sets of temperature measurements surrounding the center point may be taken, each extending further radially away from the center point toward the edge of the healed wound tissue 12. In some embodiments, the plurality of temperature measurements may include randomly or uniformly scanning the healed wound tissue 12.

[00105] A lower temperature corresponds to a higher transepidermal water loss measurement. The method 310 includes step 316 of determining a relatively low temperature and/or one of the lowest of the plurality of temperatures measured in step 314. In some embodiments, in step 316, a relatively low temperature out of the plurality of temperatures may be used. In some embodiments, in step 316, one of the lowest temperatures out of the plurality of temperatures may be used. In some embodiments, in step 316, the lowest temperature out of the plurality of temperatures may be used. Because lower temperatures correspond to higher transepidermal water loss measurements, determining the relatively low temperature within the healed wound tissue 12 is indicative of the location within the healed wound tissue 12 with the highest transepidermal water loss measurement. [00106] In step 318, the second transepidermal water loss is measured using the measuring device 14 at the location within the healed wound tissue 12 with the relatively low temperature as determined in step 316 to determine a second transepidermal water loss value. In some embodiments, the second transepidermal water loss may be measured using the measuring device 1 at the center of the healed wound tissue 12. The second transepidermal water loss measured is transmitted to the processor 16 and may be displayed on the monitor 18. The processor 16 determines the second transepidermal water loss value based, at least in part, on the second transepidermal water loss as measured by the measuring device 14. The second transepidermal water loss and the second transepidermal water loss value are stored in the memory 26 of the processor 16.

[00107] In step 320, the second transepidermal water loss value is compared to the first transepidermal water loss value. The method 310 includes decision step 322 during which the processor 16, using instructions stored in the memory 26, determines if the second transepidermal water loss value is at least two times greater than the first transepidermal water loss value. In some embodiments, the processor 16 determines if the second transepidermal water loss value is at least three times greater than the first transepidermal water loss value. Generally, the second transepidermal water loss value is compared to a multiple, integer, or real value of the first transepidermal water loss value. In some embodiments, the first transepidermal water loss value is equal to an average of multiple measured transepidermal water losses, as previously discussed.

[00108] In some embodiments, the first transepidermal water loss value is statistically determined using transepidermal water loss measurements for the reference location 24 and the database 22. In alternate embodiments, the first transepidermal water loss value may be a static value stored in the memory 26 and/or in the database 22. [00109] If the second transepidermal water loss value is less than two times the first transepidermal water loss value as determined in decision step 322, then the second transepidermal water loss value is deemed low in step 326, indicating that skin functionality of the healed wound tissue 12 has been restored. In step 326, the processor 16 transmits the first indicator to the monitor 18 for display. The first indicator suggests that the healed wound tissue 12 is not at risk, or is at a reduced risk, for reopening and recurrence because the skin barrier function at the site of wound repair is not compromised.

[00110] If the second transepidermal water loss value is at least two times greater than the first transepidermal water loss value, then the second transepidermal water loss value is deemed high in step 324. indicating that the healed wound tissue 12 has poor functionality (i.e. , non-restoration of the skin functionality of the healed wound tissue 12). The high second transepidermal water loss value is indicative of inadequate and/or deficient wound closure and may predict a risk of recurrence. The indication of the high second transepidermal water loss value allows a physician to prepare suitable intervention strategies aimed at restoring the skin functionality, and if warranted, to prevent recurrence of the wound.

[00111] In step 324, the processor 16 illustratively transmits the second indicator to the monitor 18 for display. The second indicator is different than the first indicator. The second indicator suggests that the healed wound tissue 12 is at risk for reopening and recurrence, and thus, has a compromised skin barrier function. In any case, the processor 16 illustratively stores the measured temperatures, the first and second transepidermal water loss values, and the first or second indicator in the memory 26 and/or database 22 along with corresponding patient identification information.

[00112] Another method 410 in accordance with the present disclosure is provided and shown in FIG. 5. The method 410 is substantially similar to the methods 110, 210, and 310. The description of the methods 110, 210, and 310 are incorporated by reference to apply to the method 410, except in instances when it conflicts with the specific description of the method 410.

[00113] The method 410 is provided for monitoring skin susceptible to a formation of pressure wound(s) and detecting early stage pressure wounds using the diagnostic system 10. The method 410 may be used as a diagnostic to determine if an early stage pressure wound is forming. The susceptible skin 12 is an area of skin that is experiencing pressure, for example, due to the resting position of the patient in a bed.

[00114] The method 410 includes step 412 of measuring a plurality of temperatures of various locations within the susceptible skin 12 using the thermographic imager 19. In some embodiments, thermographic imaging of an entirety of the susceptible skin 12 is performed. In this embodiment, a scan of temperatures of the susceptible skin 12 is performed. The plurality of temperature measurements and the location within the susceptible skin 12 corresponding to each measured temperature are transmitted to the processor 16 and may be displayed on the monitor 18. The plurality of temperature measurements and the locations at which each were measured are stored in the memory 26 of the processor 16.

[00115] Each of the plurality of temperature measurements are illustratively taken at different locations of the susceptible skin 12. For example, each of the plurality of temperature measurements are taken interior to the border (i.e. , a perimeter) of the susceptible skin 12. In some embodiments, each of the plurality of temperature measurements are taken at positions interior to the border of the susceptible skin 12 equally spaced from one another relative to the border of the susceptible skin 12. For example, different temperature measurements may be taken 360 degrees interior to the border of a circle encompassing the susceptible skin 12. In some embodiments, each of the plurality of temperature measurements includes a temperature measurement at a center point of the susceptible skin 12, followed by temperature measurements surrounding the center point of the susceptible skin 12. In some embodiments, multiple sets of temperature measurements surrounding the center point may be taken, each extending further radially away from the center point toward the border of the susceptible skin 12. In some embodiments, the plurality of temperature measurements may include randomly or uniformly scanning the susceptible skin 12.

[00116] A lower temperature corresponds to a higher transepidermal water loss measurement. The method 410 includes step 414 of determining a relatively low temperature and/or one of the lowest of the plurality of temperatures measured in step 412. In some embodiments, in step 414, a relatively low temperature out of the plurality of temperatures may be used. In some embodiments, in step 414, one of the lowest temperatures out of the plurality of temperatures may be used. In some embodiments, in step 414, the lowest temperature out of the plurality of temperatures may be used. Because lower temperatures correspond to higher transepidermal water loss measurements, determining the relatively low temperature within the susceptible skin 12 is indicative of the location within the susceptible skin 12 with the highest transepidermal water loss measurement.

[00117] In step 416, transepidermal water loss is measured using the measuring device 14 at the location within the susceptible skin 12 with the relatively low temperature as determined in step 414 to determine a transepidermal water loss value. In some embodiments, transepidermal water loss may be measured using the measuring device 14 at the center of the susceptible skin 12. The transepidermal water loss is transmitted to the processor 16 and may be displayed on the monitor 18. The processor 16 determines the transepidermal water loss value based, at least in part, on the transepidermal water loss as measured by the measuring device 14. The transepidermal water loss and the transepidermal water loss value are stored in the memory 26 of the processor 16. [00118] The method 410 includes decision step 418 of determining if a predetermined number of transepidermal water loss values have been determined. For example, the method 410 may continue until eight transepidermal water loss values are determined and collected. Though, it should be understood that the method 410 may continue until any number of transepidermal water loss values are collected. If the predetermined number of transepidermal water loss values have not been determined and collected, then the method 410 proceeds to step 420. If the predetermined number of transepidermal water loss values have been determined and collected, then the method 410 proceeds to step 422.

[00119] At step 420, a specified period of time passes before the method 410 continues to step 412. In some embodiments, the specified period of time may be one day, two days, three days, four days, five days, six days, seven days, etc. For example, the specified period may be four days. Though, it will be understood that the specified period of time may be any time interval. After step 420 is completed, the method 410 continues to steps 412 through step 416 as previously described. Because the specified period of time has passed in step 420, the measured temperatures of step 412, and thus, the measured transepidermal water loss of step 416 may be different than the measurements previously made during the first iteration of method 410.

[00120] After the predetermined number of transepidermal water loss values have been collected, as determined in decision step 418, the method 410 proceeds to step 422. In step 422, the transepidermal water loss values are compared. The method 410 includes decision step 424 during which the processor 16, using instructions stored in the memory 26, determines if the transepidermal water loss values are increasing over time. For example, the processor 16 may develop a graph showing the transepidermal water loss values as a function of time. [00121] An increasing transepidermal water loss value over time is indicative of an increased risk (or a risk) of the formation of a pressure wound at the susceptible skin 12. In some embodiments, a generally increasing trend in transepidermal water loss value over time is indicative of an increased risk (or a risk), such that one transepidermal water loss value that is lower than a previously measured value may not preclude a finding of an increased risk. [00122] As determined in decision step 424, an increase in the transepidermal water loss values over time is indicative of an increased risk of the formation of a pressure wound at the susceptible skin 12, and thus, predicts that a pressure ulcer may be formed at the susceptible skin 12 before the pressure ulcer has formed as indicated in step 426. A physician may intervene, for example, through pressure offloading, to relieve pressure at the susceptible skin 12 and prevent the formation of the pressure ulcer. In step 426, the processor 16 illustratively transmits a second indicator to the monitor 18 for display. The second indicator suggests that the susceptible skin 12 is at risk for forming a pressure wound.

[00123] The transepidermal water loss values not generally increasing over time as determined in decision step 424 is indicative of minimal risk of the formation of a pressure wound, as indicated in step 428. In other words, a generally decreasing or a generally steady transepidermal water loss value over time indicates minimal risk of the formation of a pressure wound. In some embodiments, a generally decreasing trend in transepidermal water loss value over time is indicative of no risk, such that one transepidermal water loss value that is greater than a previously measured value may not preclude a finding of no risk. In step 428, the processor 16 transmits a first indicator to the monitor 18 for display. The first indicator suggests that the susceptible skin 12 is not at risk, or is at a reduced risk, for the formation of a pressure wound. In any case, the processor 16 illustratively stores the first and second transepidermal water loss values and the first or second indicator in the memory 26 and/or database 22 along with corresponding patient identification information.

[00124] While the disclosure has been illustrated and described in detail in the foregoing drawings and description, the same is to be considered as exemplary and not restrictive in character, it being understood that only illustrative embodiments thereof have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected.

Claims

What is claimed is:

1 . A method for determining functionality of healed wound tissue, the method comprising: measuring transepidermal water loss at a reference location to determine a first transepidermal water loss value, wherein the reference location is i) within about 2 inches to about 4 inches of an edge of the healed wound tissue; or ii) located at the same position as the healed wound tissue on a contralateral limb; measuring transepidermal water loss at the healed wound tissue to determine a second transepidermal water loss value, and comparing the second transepidermal water loss value to the first transepidermal water loss value, wherein the second transepidermal water loss value being at least two times greater than the first transepidermal water loss value is indicative of non-restoration of skin functionality of the healed wound tissue.

2. The method of claim 1 , wherein the second transepidermal water loss value being less than two times the first transepidermal water loss value is indicative of restoration of skin functionality of the healed wound tissue.

3. The method of claim 1 or 2, wherein the reference location is within 3 inches of the edge of the healed wound tissue.

4. The method of claim 1 or 2, wherein a plurality of measurements of transepidermal water loss are determined at the reference location, each of the plurality of measurements taken at a different location, each within about 2 inches to about 4 inches of an outer edge perimeter of the healed wound tissue, and wherein the first transepidermal water loss value is an average of the plurality of measurements.

5. The method of claim 4, wherein the different locations of the plurality of measurements of transepidermal water loss are equally spaced from one another relative to a perimeter of a circle encompassing the healed wound tissue.

6. The method of claim 4 or 5, wherein the plurality of measurements of transepidermal water loss includes two, three, or four measurements.

7. The method of claim 1 or 2, wherein a plurality of first measurements of transepidermal water loss are determined at the reference location, each of the plurality of first measurements taken at a different location, each within about 2 inches to about 4 inches of an outer edge perimeter of the healed wound tissue, and wherein the first transepidermal water loss value is an average of the plurality of first measurements.

8. The method of claim 7, wherein a plurality of second measurements of transepidermal water loss are determined within the healed wound tissue, each of the plurality of second measurements taken at a different location, each interior to the outer edge perimeter of the healed wound tissue, and wherein the second transepidermal water loss value is an average of the plurality of second measurements.

9. The method of claim 8, wherein the second transepidermal water loss value being less than two times the first transepidermal water loss value is indicative of restoration of skin functionality of the healed wound tissue.

10. The method of claim 8, wherein the plurality of second measurements of transepidermal water loss includes two, three, or four measurements.

11 . The method of any of claims 1 -6, further comprising measuring a plurality of temperatures at a plurality of locations within the healed wound tissue to determine, based on one or a subset of the plurality of temperatures, one or more locations within the healed wound tissue to measure the transepidermal water loss.

12. The method of claim 11 , further comprising using a lowest or near lowest one of the plurality of temperatures to determine the one or more locations within the healed wound tissue to measure the transepidermal water loss.

13. A method of monitoring an area of skin susceptible to formation of pressure wounds for detection of an early stage pressure wound, the method comprising: measuring transepidermal water loss at a reference location to determine a first transepidermal water loss value, wherein the reference location is i) within about 2 inches to about 4 inches of a border of the area of skin; or ii) located at another area of skin contralateral to the area of skin, wherein the another area of skin is not susceptible to the formation of a pressure wound; measuring transepidermal water loss at the area of skin to determine a second transepidermal water loss value, and comparing the second transepidermal water loss value to the first transepidermal water loss value, wherein the second transepidermal water loss value being at least two times greater than the first transepidermal water loss value indicates a risk of the formation of a pressure wound in the area of skin.

14. The method of claim 13, wherein the reference location is skin within three inches of the border of the area of skin.

15. The method of claim 13, wherein a plurality of measurements of transepidermal water loss are determined at the reference location, each of the plurality of measurements taken at a different location, each within about 2 inches to about 4 inches of the border of the area of skin, and wherein the first transepidermal water loss value is an average of the plurality of measurements.

16. The method of claim 15, wherein the different locations of the plurality of measurements of transepidermal water loss are equally spaced from one another relative to a perimeter of a circle encompassing the area of skin.

17. The method of claim 15 or 16, wherein the plurality of measurements of transepidermal water loss includes two, three, or four measurements.

18. The method of any of claims 13-17, wherein the second transepidermal water loss value being less than two times the first transepidermal water loss value is indicative of no risk of formation of a pressure wound in the area of skin.

19. The method of claim 13, wherein a plurality of first measurements of transepidermal water loss are determined at the reference location, each of the plurality of first measurements taken at a different location, each within about 2 inches to about 4 inches of the border of the area of skin, and wherein the first transepidermal water loss value is an average of the plurality of first measurements.

20. The method of claim 19, wherein a plurality of second measurements of transepidermal water loss are determined at the area of skin, each of the plurality of second measurements taken at a different location, each interior to the border of the area of skin, and wherein the second transepidermal water loss value is an average of the plurality of second measurements.

21 . The method of claim 19 or 20, wherein the second transepidermal water loss value being less than two times the first transepidermal water loss value is indicative of no risk of formation of a pressure wound in the area of skin.

22. The method of claim 20 or 21 , wherein the plurality of second measurements of transepidermal water loss includes two, three, or four measurements.

23. The method of any of claims 13-18, further comprising measuring a plurality of temperatures at a plurality of locations within the area of skin to determine, based on one or a subset of the plurality of temperatures, one or more locations within the area of skin to measure the transepidermal water loss.

24. The method of claim 23, further comprising using a lowest or near lowest one of the plurality of temperatures to determine the one or more locations within the area of skin to measure the transepidermal water loss.

25. A method for monitoring skin, the method comprising: measuring transepidermal water loss at a reference location to determine a first transepidermal water loss value, wherein the reference location is i) within about 2 inches to about 4 inches of an edge of a monitored area of skin; or ii) located at the same position as the monitored area of skin on a contralateral limb; measuring transepidermal water loss at the monitored area of skin to determine a second transepidermal water loss value, and comparing the second transepidermal water loss value to the first transepidermal water loss value, wherein the second transepidermal water loss value being at least two times greater than the first transepidermal water loss value indicates a risk of damage to the monitored area of skin.

26. The method of claim 25, wherein the monitored area of skin is healed wound tissue.

27. The method of claim 26, wherein the second transepidermal water loss value being greater than two times the first transepidermal water loss value is indicative of non-restoration of skin functionality of the healed wound tissue, and wherein the second transepidermal water loss value being less than two times the first transepidermal water loss value is indicative of restoration of skin functionality of the healed wound tissue.

28. The method of claim 25, wherein the monitored area of skin is skin susceptible to the formation of pressure wounds.

29. The method of claim 28, wherein the second transepidermal water loss value being greater than two times the first transepidermal water loss value is indicative of a risk of formation of a pressure wound at the monitored area of skin, and wherein the second transepidermal water loss value being less than two times the first transepidermal water loss value is indicative of no risk of formation of a pressure wound at the monitored area of skin.

30. The method of any of claims 25-29, wherein the reference location is within 3 inches of the edge of the monitored area of skin.

31 . The method of any of claims 25-29, wherein a plurality of measurements of transepidermal water loss are determined at the reference location, each of the plurality of measurements taken at a different location, each within about 2 inches to about 4 inches of an outer edge perimeter of the monitored area of skin, and wherein the first transepidermal water loss value is an average of the plurality of measurements.

32. The method of claim 31 , wherein the different locations of the plurality of measurements of transepidermal water loss are equally spaced from one another relative to a perimeter of a circle encompassing the monitored area of skin.

33. The method of claim 31 or 32, wherein the plurality of measurements of transepidermal water loss includes two, three, or four measurements.

34. The method of any of claims 25-29, wherein a plurality of first measurements of transepidermal water loss are determined at the reference location, each of the plurality of first measurements taken at a different location, each within about 2 inches to about 4 inches of an outer edge perimeter of the monitored area of skin, and wherein the first transepidermal water loss value is an average of the plurality of first measurements.

35. The method of claim 34, wherein a plurality of second measurements of transepidermal water loss are determined at the monitored area of skin, each of the plurality of second measurements taken at a different location, each interior to the outer edge perimeter of the monitored area of skin, and wherein the second transepidermal water loss value is an average of the plurality of second measurements.

36. The method of claim 35, wherein the plurality of second measurements of transepidermal water loss includes two, three, or four measurements.

37. The method of any of claims 25-29, further comprising measuring a plurality of temperatures at a plurality of locations within the monitored area of skin to determine, based on one or a subset of the plurality of temperatures, one or more locations within the monitored area of skin to measure the transepidermal water loss.

38. The method of claim 37, further comprising using a lowest or near lowest one of the plurality of temperatures to determine the one or more locations within the monitored area of skin to measure the transepidermal water loss.

39. A method of monitoring an area of skin susceptible to formation of pressure wounds for detection of an early stage pressure wound, the method comprising:

(i) measuring a plurality of temperatures at a plurality of locations within the area of skin,

(ii) determining a lowest or near lowest one of the plurality of temperatures, (iii) measuring transepidermal water loss at the location within the area of skin having the lowest or near lowest one of the plurality of temperatures to determine a transepidermal water loss value,

(iv) waiting a specified time period,

(v) repeating (i), (ii), and (iii) after waiting the specified time period, and

(vi) comparing the transepidermal water loss values, wherein a generally increasing transepidermal water loss value over time indicates a risk of formation of a pressure wound at the area of skin.

40. The method of claim 39, wherein the lowest or near lowest one of the plurality of temperatures is the lowest temperature of the plurality of temperatures.

41 . The method of claim 39 or 40, wherein a generally decreasing or a generally steady transepidermal water loss value over time indicates no risk of formation of a pressure wound at the area of skin.

42. A diagnostic system for monitoring an area of monitored skin, the system comprising: a measuring device configured to measure transepidermal water loss, a processor, and a memory having instructions stored therein executable by the processor to cause the processor to (a) determine a first transepidermal water loss value based, at least in part, on a measured transepidermal water loss at a reference location of skin, (b) determine a second transepidermal water loss value based, at least in part, on a measured transepidermal water loss within the area of monitored skin, and (c) compare the second transepidermal water loss value to the first transepidermal water loss value, wherein the second transepidermal water loss value being at least two times greater than the first transepidermal water loss value indicates a risk of damage to the area of monitored skin.

43. The system of claim 42, wherein the reference location is i) within about 2 inches to about 4 inches of an outer edge perimeter of the area of monitored skin; or ii) located at the same position as the area of monitored skin on a contralateral limb.

44. The system of claim 42 or 43, wherein the area of monitored skin is healed wound tissue.

45. The system of claim 44, wherein the second transepidermal water loss value being greater than two times the first transepidermal water loss value is indicative of non-restoration of skin functionality of the healed wound tissue, and wherein the second transepidermal water loss value being less than two times the first transepidermal water loss value is indicative of restoration of skin functionality of the healed wound tissue.

46. The system of claim 42 or 43, wherein the area of monitored skin is skin susceptible to formation of a pressure wound.

47. The system of claim 46, wherein the second transepidermal water loss value being greater than two times the first transepidermal water loss value is indicative of a risk of formation of a pressure wound at the area of monitored skin, and wherein the second transepidermal water loss value being less than two times the first transepidermal water loss value is indicative of no risk of formation of a pressure wound at the area of monitored skin.