Apparatus for determining damaged tissue using sub-epidermal moisture measurements

Abstract

The present disclosure provides apparatuses and computer readable media for measuring sub-epidermal moisture in patients to determine damaged tissue for clinical intervention. The present disclosure also provides methods for determining damaged tissue,

Description

(19) *EP004652923A2* (11) EP 4 652 923 A2 (12) EUROPEAN PATENT APPLICATION (43) Date of publication: 26.11.2025 Bulletin 2025 / 48 (21) Application number: 25208264.9 (22) Date of filing: 21.04.2016 (51) International Patent Classification (IPC): A61B 5 / 00 (2006.01) (52) Cooperative Patent Classification (CPC): A61B 5 / 0537; A61B 5 / 0531; A61B 5 / 445; A61B 5 / 447; A61B 5 / 4875; A61B 5 / 742; A61B 5 / 6843; A61B 2560 / 0468; A61B 2562 / 046 (84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR (30) Priority: 24.04.2015 US 201562152549 P (62) Document number(s) of the earlier application(s) in accordance with Art. 76 EPC: 24158801.1 / 4 349 248 19186393.5 / 3 571 987 16166483.4 / 3 092 946 (71) Applicant: Bruin Biometrics, LLC Los Angeles, CA 90067 (US) (72) Inventors: • Tonar, Ya-Chen Los Angeles, CA 90024 (US) • Rhodes, Shannon Los Angeles, CA 90024 (US) • Clendenin, Marta Los Angeles, CA 90024 (US) • Burns, Martin Los Angeles, California 90024 (US) • Kindah, Jaradeh Los Angeles, CA 90024 (US) (74) Representative: Uexküll & Stolberg Partnerschaft von Patent‑ und Rechtsanwälten mbB Beselerstraße 4 22607 Hamburg (DE) (54) APPARATUS FOR DETERMINING DAMAGED TISSUE USING SUB‑EPIDERMAL MOISTURE MEASUREMENTS (57) The present disclosure provides apparatuses and computer readablemedia formeasuring sub-epider- malmoisture in patients to determine damaged tissue for clinical intervention. The present disclosure also pro- vides methods for determining damaged tissue, EP 4 65 2 92 3 A 2 Processed by Luminess, 75001 PARIS (FR) 2 1 EP 4 652 923 A2 2 Description RELATED CASES

[0001] This application claims priority to United States Provisional Application Serial No. 62 / 152,549, filed April 24, 2015, the entirety of which is incorporated by refer- ence herein. All references referred to herein are herein incorporated by reference in their entireties. FIELD OF INVENTION

[0002] The present disclosure provides apparatuses and computer readablemedia formeasuring sub-epider- malmoisture in patients to determine damaged tissue for clinical intervention. The present disclosure also pro- vides methods for determining damaged tissue. BACKGROUND

[0003] The skin is the largest organ in the human body. It is readily exposed to different kinds of damages and injuries. When the skin and its surrounding tissues are unable to redistribute external pressure and mechanical forces, pressure ulcers may be formed. Pressure ulcers pose a significant health and economic concern inter- nationally, across both acute and long-tenn care settings. Pressure ulcers impact approximately 2.5 million people a year in the United States and an equivalent number in the European Union. In long-term and critical care set- tings, up to 25%of elderly and immobile patients develop pressure ulcers. Approximately 60,000 U.S. patients die per year due to infection and other complications from pressure ulcers.

[0004] Most pressure ulcers occur over bony promi- nences, where there is less tissue for compression and the pressure gradient within the vascular network is altered. Pressure ulcers are categorized in one of four stages, ranging from the earliest stage currently recog- nized, inwhich theskin remains intact butmayappear red over a bony prominence (Stage 1), to the last stage, in which tissue is broken and bone, tendon or muscle is exposed (Stage 4). Detecting pressure ulcers before the skin breaks and treating them to avoid progression to later stages is a goal of policy makers and care providers in major economies. Most pressure ulcers are preven- table, and if identified before the first stage of ulceration, deterioration of the underlying tissue can be halted.

[0005] Of the four main stages of pressure ulcers, the earliest stage currently recognized (Stage 1) is the least expensive to treat at anaverageof $2,000per ulcer, but is also the hardest to detect. In many cases, injuries on the epidermis layer are not present or apparent when the underlying subcutaneous tissue has become necrotic. Asa result, it is common that a clinician’s first diagnosis of a pressure ulcer in a patient occurs at late stages of the ulcer development -‑ at which time the average cost of treatment is $43,000 per Stage 3 ulcer, or $129,000 per Stage 4 ulcer. If clinicians could identify and diagnose pressure ulcers at earlier stages of ulcer development, the healing process would be considerably shortened and the treatment costs would be significantly lower.

[0006] To treat pressure ulcers in a timely and effective manner, clinicians need to be able to identify, with preci- sion, the ulceration area. However, the current standard to detect pressure ulcers is by visual inspection, which is subjective, unreliable, untimely, and lacks specificity. SUMMARY OF THE INVENTION

[0007] In an aspect, the present disclosure provides for, and includes, an apparatus for identifying damaged tissue. The apparatus may comprise one or more elec- trodes capable of interrogating tissue at and around an anatomical site, where each of the one or more electro- des may be configured to emit and receive a radiofre- quency signal to generate a bioimpedance signal; a circuit that may be electronically coupled to the one or more electrodes and may be configured to convert the bioimpedance signal into a sub-epidermal moisture ("SEM") value; a processor that may be electronically coupled to the circuit and may be configured to receive the SEM value; and a non-transitory computer readable medium that may be electronically coupled to the pro- cessor and may comprise instructions stored thereon that, when executed on the processor, may perform the steps of receiving from the processor a SEM value measured at the anatomical site and at least two SEM values measured around the anatomical site and their relativemeasurement locations; determiningamaximum SEM value from the measurements around the anato- mical site; determining a difference between the max- imumSEMvalueandeachof the at least twoSEMvalues measured around the anatomical site; and flagging the relative measurement locations associated with a differ- ence greater than a predetermined value as damaged tissue. In another aspect, a difference is determined between the maximum SEM value and a minimum SEM value measured around the anatomical site.

[0008] In yet another aspect, the apparatus may com- prise one or more electrodes capable of interrogating tissue at and around an anatomical site, where each of theoneormoreelectrodesmaybeconfigured toemit and receive a radiofrequency signal to generate a bioimpe- dance signal; a circuit that may be electronically coupled to the one or more electrodes and may be configured to convert the bioimpedance signal into a SEM value; a processor thatmaybeelectronically coupled to the circuit and may be configured to receive the SEM value; and a non-transitory computer readable medium that may be electronically coupled to the processor and may com- prise instructions stored thereon that, when executed on the processor, may perform the steps of receiving from the processor a SEM value measured at the anatomical site and at least two SEM values measured around the anatomical siteand their relativemeasurement locations; 5 10 15 20 25 30 35 40 45 50 55 3 3 EP 4 652 923 A2 4 determining an average SEM value for each group of SEM values measured at approximately equidistance from the anatomical site; determining a maximum SEM value from the average SEM values; determining a dif- ference between the maximum average SEM value and each of the average SEM values measured around the anatomical site; and flagging the relative measurement locations associated with a difference greater than a predetermined value as damaged tissue.

[0009] In yet another aspect, the present disclosure provides for, and includes, a non-transitory computer readable medium for identifying damaged tissue. The non-transitory computer readablemediummaycomprise instructions stored thereon, that when executed on a processor, may perform the steps of receiving a SEM value at an anatomical site and at least two SEM values measured around the anatomical site and their relative measurement locations; determining a maximum SEM value from the measurements around the anatomical site, determining a difference between the maximum SEM value and each of the at least two SEM values measured around the anatomical site; and flagging the relative measurement locations associated with a differ- ence greater than a predetermined value as damaged tissue. In another aspect, a difference is determined between the maximum SEM value and a minimum SEM value measured around the anatomical site.

[0010] In another aspect, the non-transitory computer readable medium may comprise instructions stored thereon thatwhenexecuted onaprocessor,mayperform the steps of receiving a SEM value at an anatomical site, and at least two SEM values measured around the ana- tomical site and their relative measurement locations; determining an average SEM value for each group of SEM values measured at approximately equidistance from the anatomical site; determining a maximum SEM value from the average SEM values; determining a dif- ference between the maximum average SEM value and each of the average SEM values measured around the anatomical site; and flagging the relative measurement locations associated with a difference greater than a predetermined value as damaged tissue.

[0011] In a further aspect, the present disclosure pro- vides for, and includes, methods for identifying damaged tissue.Amethodaccording to thepresent disclosuremay comprise measuring at least three sub-epidermal moist- ure values at and around an anatomical site using an apparatus thatmaycompriseoneormoreelectrodes that may be capable of interrogating tissue at and around an anatomical site, wherein each of the one or more elec- trodes may be configured to emit and receive a radio- frequency signal to generate a bioimpedance signal; a circuit that may be electronically coupled to the one or more electrodes and configured to convert the bioimpe- dance signal into a SEM value; a processor that may be electronically coupled to the circuit and configured to receive the SEM value; and a non-transitory computer readable medium that may be electronically coupled to the processor and may comprise instructions stored thereon that when executed on the processor, may per- form the steps of receiving from the processor a SEM value measured at the anatomical site and at least two SEM values measured around the anatomical site and their relativemeasurement locations; determiningamax- imum SEM value from the measurements around the anatomical site; determining a difference between the maximum SEM value and each of the at least two SEM values measured around the anatomical site; and flag- ging the relative measurement locations associated with a difference greater than a predetermined value as da- maged tissue. In another aspect, a difference is deter- mined between themaximumSEMvalue andaminimum SEM value measured around the anatomical site. The methodmay further comprise obtaining the relativemea- surement locations flagged as damaged tissue from the apparatus.

[0012] In another aspect, a method according to the present disclosure may comprise measuring at least three sub-epidermal moisture values at and around an anatomical site using an apparatus that may comprise one or more electrodes that may be capable of interro- gating tissue at and around an anatomical site, wherein each of the one or more electrodes may be configured to emit and receive a radiofrequency signal to generate a bioimpedance signal; a circuit that may be electronically coupled to the one or more electrodes and configured to convert the bioimpedance signal into a SEM value; a processor thatmaybeelectronically coupled to the circuit and configured to receive the SEM value; and a non- transitory computer readable medium that may be elec- tronically coupled to the processor and may comprise instructions stored thereon that, when executed on the processor, may perform the steps of receiving from the processor a SEM value measured at the anatomical site and at least two SEM values measured around the ana- tomical site and their relative measurement locations; determining an average SEM value for each group of SEM values measured at approximately equidistance from the anatomical site; determining a maximum SEM value from the average SEM values; determining a dif- ference between the maximum average SEM value and each of the average SEM values measured around the anatomical site; and flagging the relative measurement locations associated with a difference greater than a predetermined value as damaged tissue. The method may further comprise obtaining the relative measure- ment locations flagged as damaged tissue from the ap- paratus.

[0013] In a further aspect, the present disclosure pro- vides for, and includes, methods for generating a SEM image indicating damaged tissue on an anatomical gra- phical representation.TheSEM imagemaybegenerated by acquiring parameters of an anatomical site to be interrogated; measuring at least three sub-epidermal moisture values at and around an anatomical site using an apparatus that may comprise one or more electrodes 5 10 15 20 25 30 35 40 45 50 55 4 5 EP 4 652 923 A2 6 thatmay be capable of interrogating tissue at and around an anatomical site, wherein each of the one or more electrodes may be configured to emit and receive a radiofrequency signal to generate a bioimpedance sig- nal; a circuit thatmay be electronically coupled to the one or more electrodes and configured to convert the bioim- pedance signal into a SEM value; a processor that may be electronically coupled to the circuit and configured to receive the SEM value; and a non-transitory computer readable medium that may be electronically coupled to the processor and may comprise instructions stored thereon that when executed on the processor, may per- form the steps of receiving from the processor a SEM value measured at the anatomical site, and at least two SEM values measured around anatomical site and their relativemeasurement locations; determiningamaximum SEM value from the measurements around the anato- mical site, determining a difference between the max- imumSEMvalueandeachof the at least twoSEMvalues measured around the anatomical site; and flagging the relative measurement locations associated with a differ- ence greater than a predetermined value as damaged tissue. In another aspect, a difference is determined between the maximum SEM value and a minimum SEM value measured around the anatomical site. The methodmay further compriseplotting themeasuredSEM values in accordance with their relative measurement locations on a graphical representation of an area de- fined by the parameters of the anatomical site, and indicating the measurement locations that are flagged as damaged tissue.

[0014] In yet another aspect, the SEM image may be generated by acquiring parameters of an anatomical site to be interrogated; measuring at least three sub-epider- mal moisture values at and around an anatomical site using an apparatus that may comprise one or more electrodes that may be capable of interrogating tissue atandaroundananatomical site,whereineachof theone ormoreelectrodesmaybeconfigured toemit and receive a radiofrequency signal to generate a bioimpedance signal; a circuit that may be electronically coupled to the one or more electrodes and configured to convert the bioimpedance signal into a SEM value; a processor that may be electronically coupled to the circuit and configured to receive the SEM value; and a non-transi- tory computer readable medium that may be electroni- cally coupled to the processor andmay comprise instruc- tions stored thereon that, when executed on the proces- sor, may perform the steps of receiving from the proces- sor a SEM value measured at the anatomical site, and at least two SEM values measured around anatomical site and their relativemeasurement locations; determiningan average SEM value for each group of SEM values mea- sured at approximately equidistance from the anatomical site; determining a maximum SEM value from the aver- age SEM values; determining a difference between the maximum average SEM value and each of the average SEM values measured around the anatomical site; and flagging the relative measurement locations associated with a difference greater than a predetermined value as damaged tissue. The method may further comprise plot- ting the measured SEM values in accordance with their relativemeasurement locations on a graphical represen- tation of an area defined by the parameters of the anato- mical site, and indicating themeasurement locations that is flagged as damaged tissue. BRIEF DESCRIPTION OF THE FIGURES

[0015] Some aspects of the disclosure are herein de- scribed, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and are for purposes of illustrative discussion of embodiments of the disclosure. In this regard, the description, taken with the drawings, make apparent to those skilled in the art how aspects of the disclosure may be practiced. Figure 1 - An exemplary apparatus according to the present disclosure, comprising one coaxial elec- trode. Figure 2 - An exemplary sensing unit of the appara- tus according to the present disclosure, comprising more than one coaxial electrode. Figure 3A - An exemplary coaxial electrode accord- ing to the present disclosure. Figure 3B - Exemplary coaxial electrodes con- structed with a point source electrode surrounded by six hexagon pad electrodes according to the present disclosure. Figure 3C - An exemplary array of hexagon pad clectrodes where each of the electrodes may be programmed to functionasdifferentpartsof acoaxial electrode in accordance with the present disclosure. Figure 3D -Sample electronic connection of an array of hexagonal pad electrodes allowing for coaxial electrode emulation in accordance with the present disclosure. Figure 3E - An exemplary array of coaxial electrodes electronically coupled together. Figure 4 - A sample measurement scheme accord- ing to the present disclosure. Figure 5A - Sample SEM measurement results ob- tained in accordancewith themethods in the present disclosure, represented as a SEM map. Figure5B -SampleSEMmeasurement results along the x-axis of Figure 5A plotted on a graph. Figure5C -SampleSEMmeasurement results along the y-axis of Figure 5A plotted on a graph. Figure 6A - An exemplary method for taking SEM measurements starting at the posterior heel. Figure 6B - An exemplary method for taking SEM measurements starting at the lateral heel. Figure 6C - An exemplary method for taking SEM measurements starting at the medial heel. 5 10 15 20 25 30 35 40 45 50 55 5 7 EP 4 652 923 A2 8 Figure 7A - Sample visual assessment of damaged tissue around a sacrum. Figure 7B - Sample SEM measurement results of damaged tissue obtained in accordance with the methods in the present disclosure. Figure 8A - Sample visual assessment of healthy tissue around a sacrum. Figure 8B - Sample SEM measurement results of healthy tissue obtained in accordancewith themeth- ods in the present disclosure. Figure 9A - A sample SEM map obtained in accor- dance with the methods in the present disclosure. Figure 9B - Corresponding visual assessment of damaged tissue of Figure 9A. Figure 10 - A sample SEM image obtained in accor- dance with the methods in the present disclosure. Figure 11‑ Sample time-lapsed SEM images show- ing the sensitivity of the detection apparatuses and methods in the present disclosure. Figure 12A - A sample graphical representation of a finite element model showing the depth of various SEM levels in accordance with the methods in the present disclosure. Figure 12B - A sample plot of SEMmeasurements at various depth of a skin-like material. DETAILED DESCRIPTION

[0016] This description is not intended to be a detailed catalog of all the different ways in which the disclosure may be implemented, or all the features that may be added to the instant disclosure. For example, features illustrated with respect to one embodiment may be in- corporated into other embodiments, and features illu- strated with respect to a particular embodiment may be deleted from that embodiment. Thus, the disclosure con- templates that in some embodiments of the disclosure, any feature or combination of features set forth herein can be excluded or omitted. In addition, numerous varia- tions and additions to the various embodiments sug- gested herein will be apparent to those skilled in the art in light of the instant disclosure, which do not depart from the instant disclosure. In other instances, well- known structures, interfaces, and processes have not been shown in detail in order not to unnecessarily ob- scure the invention. It is intended that no part of this specification be construed to effect a disavowal of any part of the full scopeof the invention.Hence, the following descriptions are intended to illustrate some particular embodiments of the disclosure, and not to exhaustively specify all permutations, combinations and variations thereof.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used in the description of the disclosure herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure.

[0018] All publications, patent applications, patents and other references cited herein are incorporated by reference in their entireties for the teachings relevant to the sentence and / or paragraph in which the reference is presented. References to techniques employed herein are intended to refer to the techniques as commonly understood in the art, including variations on those tech- niques or substitutions of equivalent techniques that would be apparent to one of skill in the art.

[0019] Unless the context indicates otherwise, it is specifically intended that the various features of the dis- closure described herein can be used in any combina- tion.Moreover, the present disclosure also contemplates that in some embodiments of the disclosure, any feature or combination of features set forth herein can be ex- cluded or omitted.

[0020] The methods disclosed herein comprise one or more steps or actions for achieving the described meth- od. The method steps and / or actions may be inter- changed with one another without departing from the scope of the present invention. In other words, unless a specific order of steps or actions is required for proper operation of the embodiment, the order and / or use of specific steps and / or actions may be modified without departing from the scope of the present invention.

[0021] As used in the description of the disclosure and the appended claims, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0022] As used herein, "and / or" refers to and encom- passes any and all possible combinations of one ormore of the associated listed items, as well as the lack of combinations when interpreted in the alternative ("or").

[0023] The terms "about" and "approximately" as used herein when referring to a measurable value such as a length, a frequency, or a SEMvalue and the like, ismeant to encompass variations of± 20%,± 10%,± 5%,± 1%, ± 0.5%, or even ± 0.1% of the specified amount.

[0024] As used herein, phrases such as "between X and Y" and "between about X and Y" should be inter- preted to include X and Y. As used herein, phrases such as "between about X and Y"mean "between about X and about Y" and phrases such as "from about X to Y" mean "from about X to about Y."

[0025] The terms "comprise," "comprises," and "com- prising"asusedherein, specify thepresenceof thestated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addi- tion of one ormore other features, integers, steps, opera- tions, elements, components, and / or groups thereof.

[0026] Asusedherein, the transitional phrase "consist- ing essentially of"means that the scope of a claim is to be interpreted toencompass thespecifiedmaterialsor steps recited in the claim and those that do not materially affect the basic and novel characteristic(s) of the claimed dis- closure. Thus, the term "consisting essentially of" when used in a claim of this disclosure is not intended to be 5 10 15 20 25 30 35 40 45 50 55 6 9 EP 4 652 923 A2 10 interpreted to be equivalent to "comprising."

[0027] As used herein, the term "sub-epidermal moist- ure" refers to the increase in tissue fluid and local edema caused by vascular leakiness and other changes that modify the underlying structure of the damaged tissue in the presence of continued pressure on tissue, apoptosis, necrosis, and the inflammatory process.

[0028] As used herein, a "system" may be a collection of devices in wired or wireless communication with each other.

[0029] Asusedherein, "interrogate" refers to the use of radiofrequency energy to penetrate into a patient’s skin.

[0030] As used herein a "patient" may be a human or animal subject.

[0031] An exemplary apparatus according to the pre- sent disclosure is shown in Figures 1 and 2. It will be understood that these are examples of an apparatus for measuring sub-epidermal moisture ("SEM"). In some embodiments, the apparatus according to the present disclosure may be a handheld device, a portable device, a wired device, a wireless device, or a device that is fitted to measure a part of a human patient. U.S. Publication No. 2014 / 0288397 A1 to Sarrafzadeh et al. is directed to a SEM scanning apparatus, which is incorporated herein by reference in its entirety.

[0032] In certain embodiments according to the pre- sent disclosure, the apparatus may comprise one or more electrodes. In one aspect according to the present disclosure, it may be preferable to use coaxial electrodes over electrodes such as tetrapolar ECG electrodes be- cause coaxial electrodes are generally isotropic, which may allow SEM values to be taken irrespective of the direction of electrode placement. The SEM values mea- sured by coaxial electrodes may also be representative of the moisture content of the tissue underneath the coaxial electrodes, rather than the moisture content of the tissue surface across two bi-polar electrodes spaced apart.

[0033] In someembodiments, theapparatusmaycom- prise two or more coaxial electrodes, three or more coaxial electrodes, four or more coaxial electrodes, five or more coaxial electrodes, ten or more coaxial electro- des, fifteen or more coaxial electrodes, twenty or more coaxial electrodes, twenty five or more coaxial electro- des, or thirty or more coaxial electrodes. In some embo- diments, the aforementioned coaxial electrodes may be configured to emit and receive an RF signal at a fre- quency of 32 kilohertz (kHz). In other embodiments, the coaxial electrodesmay be configured to emit and receive an RF signal at a frequency of from about 5 kHz to about 100 kHz, fromabout 10 kHz to about 100 kHz, fromabout 20 kHz to about 100 kHz, from about 30 kHz to about 100 kHz, from about 40 kHz to about 100 kHz, from about 50 kHz to about 100 kHz, from about 60 kHz to about 100 kHz, from about 70 kHz to about 100 kHz, from about 80 kHz to about 100 kHz, or from about 90 kHz to about 100 kHz. In yet another embodiment, the coaxial electrodes may be configured to emit and receive an RF signal at a frequency of from about 5 kHz to about 10 kHz, from about 5 kHz toabout 20kHz, fromabout 5 kHz toabout 30 kHz, from about 5 kHz to about 40 kHz, from about 5 kHz to about 50 kHz, from about 5 kHz to about 60 kHz, from about 5 kHz toabout 70kHz, fromabout 5 kHz toabout 80 kHz, or from about 5 kHz to about 90 kHz. In a further embodiment, thecoaxial electrodesmaybeconfigured to emit and receive an RF signal at a frequency less than 100 kHz, less than 90 kHz, less than 80 kHz, less than 70 kHz, less than60 kHz, less than50 kHz, less than40 kHz, less than 30 kHz, less than 20 kHz, less than 10 kHz, or less than 5 kHz. In certain embodiments, all of the coaxial electrodes of the apparatus may operate at the same frequency. In some embodiments, some of the coaxial electrodes of the apparatus may operate at different frequencies. In certain embodiments, the frequency of a coaxial electrode may be changed through program- ming specific pins on an integrated circuit in which they are connected.

[0034] In some embodiments according to the present disclosure, thecoaxial electrodesmaycompriseabipolar configuration having a first electrode comprising an outer annular ring disposed around a second inner circular electrode.Referring toFigure 3A, the outer ring electrode may have an outer diameter Do and an inner diameter DI that is larger than the diameter Dc of the circular inner electrode. Each inner circular electrode and outer elec- trode may be coupled electrically to one or more circuits that are capable of applying a voltage waveform to each electrode; generating a bioimpedance signal; and con- verting the capacitance signal to a SEM value. In certain embodiments, the bioimpedance signal may be a capa- citance signal generated by, e.g., measuring the differ- enceof thecurrentwaveformappliedbetween thecentral electrode and the annular ring electrode. In some embo- diments, the conversion may be performed by a 24 bit capacitance-to-digital converter. In another embodi- ment, the conversion may be a 16 bit capacitance-to- digital converter, a charge-timing capacitance to digital converter, a sigma-delta capacitance to digital converter. The one ormore circuitsmay be electronically coupled to a processor. The processormay be configured to receive the SEM value generated by the circuit.

[0035] In certain embodiments, the one or more coax- ial electrodes may have the same size. In other embodi- ments, the one or more coaxial electrodes may have different sizes, which may be configured to interrogate the patient’s skin at different depths. The dimensions of theoneormorecoaxial electrodesmaycorrespond to the depth of interrogation into the derma of the patient. Accordingly, a larger diameter electrode may penetrate deeper into the skin than a smaller pad. The desired depth may vary depending on the region of the body being scanned, or the age, skin anatomy or other char- acteristic of the patient. In someembodiments, the oneor more coaxial electrodes may be coupled to two or more separate circuits to allow independent operation of each of the coaxial electrodes. In another embodiment, all, or a 5 10 15 20 25 30 35 40 45 50 55 7 11 EP 4 652 923 A2 12 subset, of the one or more coaxial electrodes may be coupled to the same circuit.

[0036] In some embodiments, the one or more coaxial electrodes may be capable of emitting RF energy to a skin depth of 4 millimeters (mm), 3.5 mm, 3.0 mm, 2.5 mm, 2.0 mm, 1.0 mm, or 0.5 mm. In a further embodi- ment, the one or more coaxial electrodes may have an outer diameter Do fromabout 5mm to about 55mm, from about 10mm to about 50mm, fromabout 15mm to about 45 mm, or from about 20 mm to about 40 mm. In another embodiment, the outer ring of the one or more coaxial electrodes may have an inner diameter DI from about 4 mm to about 40mm, from about 9mm to about 30mm, or from about 14 mm to about 25 mm. In yet another embodiment, the inner electrode of the one or more coaxial electrodes may have a diameter Dc from about 2 mm to 7 mm, 3 mm to 6 mm, or 4 mm to 5 mm.

[0037] In a further embodiment, the one or more coax- ial electrodesmay be spaced apart at a distance to avoid interference between the electrodes. The distance may be a function of sensor size and frequency to be applied. In some embodiments, each of the one or more coaxial electrodes may be activated sequentially. In certain em- bodiments, multiple coaxial electrodes may be activated at the same time.

[0038] In certain embodiments according to the pre- sent disclosure, a coaxial electrodemaycomprise a point source surroundedbyhexagonpadelectrodes spacedat approximately equidistance, as illustrated in Figure 3B. The point source may comprise a hexagon pad elec- trode. In some embodiments, the point sourcemay com- prise two, three, four, five, or six hexagon pad electrodes. In certain embodiments, a point source may be sur- rounded by six hexagon pad electrodes. In some embo- diments, multiple coaxial electrodes may be emulated from an array comprising a plurality of hexagon pad electrodes, where each hexagon pad electrode may be programmed to be electronically coupled to a floating ground, a capacitance input, or a capacitance excitation signal, as illustrated in Figures 3C and 3D. In a further embodiment, each of the hexagon pad electrodes may be connected to amultiplexer that may have a select line that controls whether the hexagon pad electrode is con- nected to a capacitance input or a capacitance excitation signal. Themultiplexer may also have an enable line that controlswhether to connect thehexagonpadelectrode to a floating ground. In certain embodiments, the multiplex- er may be a pass-gate multiplexer. In some embodi- ments, the one or more coaxial electrodes may be ar- ranged as illustrated in Figure 3E to leveragemultiplexer technology. Without being limited to theory, the arrange- ment illustrated in Figure 3E may limit interference be- tween the one or more coaxial electrodes.

[0039] In certain embodiments, one or more coaxial electrodes may be embedded on a first side of a non- conductive substrate. In some embodiments, the sub- strate may be flexible or hard. In certain embodiments, the flexible substratemay comprise kapton, polyimide, or a combination thereof. In further embodiments, an upper coverlay may be positioned directly above the one or more coaxial electrodes. In certain embodiments, the upper coverlay may be a double-sided, copper-clad la- minate and an all-polyimide composite of a polyimide film bonded to copper foil. In some embodiments, the upper coverlay may comprise Pyralux 5 mil FR0150. Without being limited by theory, the use this upper coverlay may avoid parasitic charges naturally present on the skin surface from interfering with the accuracy and precision of SEM measurements. In some embodiments, the one or more coaxial electrodes may be spring mounted to a substrate within an apparatus according to the present disclosure.

[0040] In someembodiments, theapparatusmaycom- prise a non-transitory computer readable medium elec- tronically coupled to the processor. In certain embodi- ments, the non-transitory computer readable medium may comprise instructions stored thereon that, when executed on a processor, may perform the steps of: (1) receiving at least one SEM value at an anatomical site; (2) receiving at least two SEM values measured around the anatomical site and their relative measurement loca- tions; (3) determining a maximum SEM value from the measurements around the anatomical site; (4) determin- ing a difference between the maximum SEM value and eachof theat least twoSEMvaluesmeasuredaround the anatomical site; and (5) flagging the relative measure- ment locations associated with a difference greater than a predetermined value as damaged tissue. In another embodiment, thenon-transitory computer readablemed- ium may comprise instructions stored thereon that may carry out the following steps when executed by the pro- cessor: (1) receiving at least oneSEMvaluemeasured at an anatomical site; (2) receiving at least two SEM values measured around the anatomical site, and their relative measurement locations; (3) determining an average SEM value for each group of SEM values measured at approximately equidistance from the anatomical site; (4) determining a maximum SEM value from the average SEM values; (5) determining a difference between the maximum average SEM value and each of the average SEM values measured around the anatomical site; and (6) flagging the relative measurement locations asso- ciated with a difference greater than a predetermined valueasdamaged tissue. In yet anotherembodiment, the non-transitory computer readablemediummaycomprise instructions stored thereon that, when executed on a processor, may perform the steps of: (1) receiving at least one SEM value at an anatomical site; (2) receiving at least two SEM values measured around the anatomi- cal site and their relative measurement locations; (3) determining a maximum SEM value from the measure- ments around the anatomical site; (4) determining a minimum SEM value from the measurements around the anatomical site; (5) determining a difference between the maximum SEM value and the minimum SEM value; and (6) flagging the relative measurement locations as- 5 10 15 20 25 30 35 40 45 50 55 8 13 EP 4 652 923 A2 14 sociated with a difference greater than a predetermined value as damaged tissue. In some embodiments, the predetermined value may be 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, or 7.5. Itwill be understood that the predetermined value is not limited by design, but rather, one of ordinary skill in the art would be capable of choosing a predetermined value based on a given unit of SEM.

[0041] In further embodiments, the leading edge of inflammationmay be indicated by anSEMdifference that is equal to or greater than the predetermined value. In some embodiments, the leading edge of inflammation may be identified by the maximum values out of a set of SEM measurements.

[0042] In certain embodiments, ananatomical sitemay be a bony prominence. In further embodiments, an ana- tomical sitemay be a sternum, sacrum, a heel, a scapula, an elbow, an ear, or other fleshy tissue. In some embodi- ments, one SEM value is measured at the anatomical site. In another embodiment, an average SEM value at the anatomical site is obtained from two, three, four, five, six, seven, eight, nine, ten, or more than ten SEM values measured at the anatomical site.

[0043] The apparatuses of the present disclosure may allow the user to control the pressure applied onto a patient’s skin to allow for optimized measurement con- ditions. In certain embodiments, a first pressure sensor may be placed on a second side opposing the first side of the substrate that the coaxial electrodes aredisposedon. In a further embodiment, a second pressure sensor may be disposed on a second side opposing the first side of the substrate that the coaxial electrodes aredisposedon. In certain embodiments, the first pressure sensormay be a low pressure sensor, and the second pressure sensor may be a high pressure sensor. Together, the first and secondpressure sensorsmayallowmeasurements tobe taken at a predetermined range of target pressures. In some embodiments, a target pressuremay be about 500 g. It will be understood that the high and low pressure sensors are not limited by design, but rather, one of ordinary skill in the art would be capable of choosing these sensors based on a given range of target pres- sures. The first and second pressure sensors may be resistive pressure sensors. In some embodiments, the first and second pressure sensors may be sandwiched between the substrate and a conformal pressure pad. The conformal pressure pad may provide both support and conformity to enable measurements over body cur- vature and bony prominences.

[0044] In an embodiment, the apparatus may further comprise a plurality of contact sensors on the same planar surface as, and surrounding, each of the one or more coaxial electrodes to ensure complete contact of the one or more coaxial electrodes to the skin surface. The plurality of contact sensors may be a plurality of pressure sensors, a plurality of light sensors, a plurality of temperature sensors, a plurality of pH sensors, a plurality of perspiration sensors, a plurality of ultrasonic sensors, a plurality of bone growth stimulator sensors, or a plurality of a combination of these sensors. In some embodiments, the plurality of contact sensors may com- prise four, five, six, seven, eight, nine, or ten or more contact sensors surrounding the one or more coaxial electrodes.

[0045] In certain embodiments, the apparatus may comprise a temperature probe. In some embodiments, the temperature probe may be a thermocouple or an infrared thermometer.

[0046] In some embodiments, the apparatus may further comprise a display having a user interface. The user interface may allow the user to input measurement location data. The user interface may further allow the user to view measured SEM values and / or damaged tissue locations. In certain embodiments, the apparatus may further comprise a transceiver circuit configured to receive data from and transmit data to a remote device, such as a computer, tablet or other mobile or wearable device. The transceiver circuit may allow for any suitable form of wired or wireless data transmission such as, for example, USB, Bluetooth, or Wifi.

[0047] Methods according to the present disclosure provide for identifying damaged tissue. In some embodi- ments, the method may comprise measuring at least threeSEMvalues at and around an anatomical site using anapparatus of the present invention, and obtaining from theapparatusmeasurement locations that are flaggedas damaged tissue. In certain embodiments, measure- ments may be taken at positions that are located on one or more concentric circles about an anatomic site. Figure 4 provides a sample measurement strategy, with the center being defined by an anatomic site. In another embodiments, themeasurementsmay be taken spatially apart from an anatomic site. In yet another embodiment, themeasurementsmaybe takenon a straight line across an anatomic site. In a further embodiment, the measure- ments may be taken on a curve around an anatomic site. In certain embodiment, surface moisture and matter above a patient’s skin surface may be removed prior to the measuring step. In some embodiments, the measur- ing step may take less than one second, less than two seconds, less than three seconds, less than four sec- onds, or less than five seconds.

[0048] Having now generally described the invention, the same will be more readily understood through refer- ence to the following examples that are provided by way of illustration, and are not intended to be limiting of the present disclosure, unless specified. EXAMPLES 5 10 15 20 25 30 35 40 45 50 55 9 15 EP 4 652 923 A2 16 Example 1: Measuring sub-epidermal moisture (SEM) values at the bony prominence of the sacrum

[0049] Subjects with visually-confirmed Stage I or II pressure ulcers with unbroken skin were subjected to multiple SEM measurements at and around the boney prominence of the sacrum using an apparatus of this disclosure. Prior to performing the measurements, sur- facemoistureandmatterabove thesubjects’ skinsurface were removed. An electrode of the apparatus was ap- plied to the desired anatomical site with sufficient pres- sure to ensure complete contact for approximately one second. Additional measurements were taken at the mapped location as laid out in Figure 4.

[0050] Figure 5A shows a sample SEM map centered on an anatomical site. Figure 5B is a plot of the individual SEMvalues across the x-axis of theSEMmap. Figure 5C is a plot of the individual SEM values across the y-axis of the SEM map. Damaged tissue radiated from the center anatomical site to an edge of erythema defined by a difference in SEM values of greater than 0.5. Example 2: Taking SEM Measurements at the bony prominence of the heel

[0051] SEM measurements were taken at the heel using one of three methods below to ensure complete contact of an electrode with the skin of a human patient.

[0052] Figure6A illustratesamethodused to takeSEM measurements starting at the posterior heel using an apparatus according to the present disclosure. First, the forefoot was dorsiflexed such that the toes were pointing towards the shin. Second, an electrode was positioned at the base of the heel. The electrode was adjusted for full contact with the heel, and multiple SEM measurements were then taken in a straight line towards the toes.

[0053] Figure6B illustratesamethodused to takeSEM measurements starting at the lateral heel using an appa- ratus according to the present disclosure. First, the toes were pointed away from the body and rotated inward towards the medial side of the body. Second, an elec- trode was placed on the lateral side of the heel. The electrode was adjusted for full contact with the heel, andmultipleSEMmeasurementswere taken in a straight line towards the bottom of the foot.

[0054] Figure6C illustratesamethodused to takeSEM measurements starting at the medial heel using an ap- paratus according to the present disclosure. First, the toes were pointed away from the body and rotated out- wards toward the lateral side of the body. Second, the electrode was placed on the medial side of the heel. The electrode was adjusted for full contact with the heel, and multiple measurements were taken around the back of the heel in a curve. Example 3: Identifying a region of damaged tissue

[0055] SEM measurements were taken on a straight line, each spaced apart by 2 cm, across the sacrum of a patient. Multiple measurements were taken at a given measurement location. Figure 7A is a sample visual assessment of damaged tissue. Figure 7B is a corre- sponding plot of the averages of SEM measurements taken at each location. The edges of erythema are de- fined by differences in SEM values of greater than 0.5. Example 4: SEM measurements of healthy tissue

[0056] SEM measurements were taken on a straight line across the sacrum of a patient. Multiple measure- ments were taken at a given measurement location. Figure 8A is a sample visual assessment of healthy tissue. Figure 8B is a corresponding plot of the averages of SEMmeasurements takenat each location. The tissue is definedashealthyas thedifferences inSEMvaluesare all less than 0.5. Example 5: SEM measurement map of damaged tissue

[0057] SEMmeasurements were taken in accordance with Example 1. Figure 9A is a sample map of averaged SEM values taken on concentric rings around an anato- mical site. Figure 9B is the corresponding visual assess- ment of the patient’s skin. Compromised tissue is identi- fied by the solid circle, where the difference in SEM values compared to the maximum SEM value is greater than0.5.The leadingedgeof inflammation is identifiedby the dotted circle, where the difference in SEM values compared to the maximum SEM value is equal to or greater than 0.5. The leading edge of inflammation is identified by a dotted line, indicating the largest values in the SEM map. Example 6: Sample SEM measurement image re- presentations

[0058] SEMmeasurementswere takenwithanarrayof coaxial electrodes. Figure 10 is a sample output of aSEM measurement image showing themoisture content of the skin over a defined area. Different SEM values are in- dicated by different colors. Example 7: SEM measurements of skin moisture content over time

[0059] Moisturizer was used to simulate the onset of a pressure ulcer. 0.2 mL moisturizer was applied to the inner forearmofasubject for 60seconds.Themoisturizer was then wiped from the skin. SEMmeasurements were taken with an array of coaxial electrodes every 10 min- utes for 2 hours. Figure 11 shows a sample time lapse of anSEMmeasurement image tomonitormoisturecontent 5 10 15 20 25 30 35 40 45 50 55 10 17 EP 4 652 923 A2 18 of a test subject. Example 8: Selecting an optimal electrode for inter- rogating patient skin

[0060] Figure12A isasamplegraphical representation of a finite element model showing the depth of various SEM levels in accordance with the methods in the pre- sent disclosure. Each line indicates a SEM value and the depth of the moisture content.

[0061] Actual SEM levels in various depths of a skin- like material were measured using an apparatus accord- ing to the present disclosure. Specifically, the apparatus comprises one coaxial electrode. First, the thickness of a blister bandage,whichsimulatesaskin-likematerial,was measured and placed on the coaxial electrode. A down- ward force was then applied via a metal onto the coaxial electrode, in an acceptable range according to the pre- sent disclosure. The metal is fitted to a second metal in tubular form. The secondmetal was selected from brass, aluminum, and stainless steel. The SEM measurement was recorded. Additional blister bandages were placed atop thecoaxial electrodes for furtherSEMmeasurement recordings. Figure 12B is a sample plot of SEMmeasure- ments at various thicknesses of the blister bandages. Without being limited by theory, the variations in the SEM values in the presence of different tubular metal may be due to potential magnetic field interference. The max- imum depth of a magnetic field generated by the coaxial sensor was determined by the distance from the coaxial sensor when the metal tube no longer interfered with the magnetic field. In this example, the maximum depth ranged from 0.135 inches to 0.145 inches. Accordingly, electrodes having an optimal penetration depth could be selected to interrogate specific depths of patient skin.

[0062] While the invention has been described with reference to particular embodiments, it will be under- stood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to a particular situation or material to the teachings of the invention without departing from the scope of the inven- tion.

[0063] Therefore, it is intended that the inventionnot be limited to the particular embodiments disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope and spirit of the appended claims. CONCEPTS

[0064] Generally, the present application discloses the following concepts: Concept 1. An apparatus for identifying damaged tissue, said apparatus comprising one or more coaxial electrodes capable of inter- rogating tissueatandaroundananatomical site, wherein each of said one or more coaxial elec- trodes is configured to emit and receive a radio- frequency signal to generate a bioimpedance signal; a circuit electronically coupled to said one or more coaxial electrodes and configured to con- vert said bioimpedance signal into a sub-epider- mal moisture (SEM) value; a processor electronically coupled to said circuit and configured to receive said SEM value; and a non-transitory computer readable medium electronically coupled to said processor and comprising instructions stored thereon that when executed on said processor, perform the steps of receiving from said processor one of said SEM values measured at said anatomical site and at least two of said SEM values measured around said anatomical site and their relative measurement locations; determining a maximum SEM value from said SEM values measured around said anatomical site; determiningadifferencebetweensaidmax- imum SEM value and each of said at least two SEM values measured around said anatomical site; and flagging said relative measurement loca- tions associated with a difference greater than a predetermined threshold as da- maged tissue. Concept 2. The apparatus according to concept 1, further comprising a substrate, andwherein said one or more coaxial electrodes are embedded on a first side of said substrate. Concept 3. The apparatus according to concept 2, wherein said substrate is flexible. Concept 4. The apparatus according to concept 3, wherein said substrate comprises a material se- lected from the group consisting of Kapton, polyi- mide, and a combination thereof. Concept 5. The apparatus according to concept 3, further comprising a conformal pressure pad dis- posed in a layer adjacent to a second side opposing said first side of said substrate. Concept 6. The apparatus according to concept 2, wherein said substrate is hard. Concept 7. The apparatus according to concept 6, further comprising a first pressure sensor disposed 5 10 15 20 25 30 35 40 45 50 55 11 19 EP 4 652 923 A2 20 on a second side opposing said first side of said substrate. Concept 8. The apparatus according to concept 7, wherein said first pressure sensor is selected from a high pressure sensor and a low pressure sensor. Concept 9. The apparatus according to concept 7, further comprising a second pressure sensor dis- posed on a second side opposing said first side of said substrate. Concept 10. The apparatus according to concept 9, wherein said first pressure sensor is a low pressure sensor, and said second pressure sensor is a high pressure sensor. Concept 11. The apparatus according to concept 1, further comprising a user interface to display said SEM values and said relative measurement loca- tions associated with a difference in value greater than 0.5. Concept 12. The apparatus according to concept 1, further comprising a second circuit configured to receive and transmit data to a remote device. Concept 13. The apparatus according to concept 1, wherein said radiofrequency signal has a frequency of less than 100 kilohertz (kHz). Concept 14. The apparatus according to concept 13, wherein said radiofrequency signal has a frequency of 32 kHz. Concept 15. The apparatus according to concept 1, wherein said one or more coaxial electrodes have a diameter ranging from 4 millimeters (mm) to 40 mm. Concept 16. The apparatus according to concept 1, further comprising a temperature probe. Concept 17. A non-transitory computer readable medium for identifying damaged tissue, comprising instructions stored thereon that when executed on a processor, perform the steps of receiving from said processor at least one sub- epidermal moisture (SEM) values measured at an anatomical site and at least two of SEM values measured around said anatomical site and their relative measurement locations; determining a maximum SEM value from said SEM values measured around said anatomical site; determining a difference between said maxi- mum SEM value and each of said at least two SEM values measured around said anatomical site; and flagging said relative measurement locations associated with a difference greater than a predetermined threshold as damaged tissue. Concept 18. The non-transitory computer readable mediumaccording to concept 17, having a geometry that is configured to be incorporated in a handheld device for identifying damaged tissue. Concept 19. A method for identifying damaged tis- sue, said method comprising measuring at least three sub-epidermal moisture values at and around an anatomical site using an apparatus comprising: one or more coaxial electrodes capable of inter- rogating tissueatandaroundananatomical site, wherein each of said one or more coaxial elec- trodes is configured to emit and receive a radio- frequency signal to generate a bioimpedance signal; a circuit electronically coupled to said one or more coaxial electrodes and configured to con- vert said bioimpedance signal into a sub-epider- mal moisture (SEM) value; a processor electronically coupled to said circuit and configured to receive said SEM value; and a non-transitory computer readable medium electronically coupled to said processor and comprising instructions stored thereon that when executed on said processor, perform the steps of receiving from said processor one of said SEM values measured at said anatomical site and at least two of said SEM values measured around said anatomical site and their relative measurement locations; determining a maximum SEM value from said SEM values measured around said anatomical site; determiningadifferencebetweensaidmax- imum SEM value and each of said at least two SEM values measured around said anatomical site; and flagging said relative measurement loca- tions associated with a difference greater than a predetermined threshold as da- maged tissue; and obtaining said measurement locations flagged as damaged tissue from said apparatus. Concept 20. The method according to concept 19, wherein said anatomical site is a bony prominence. Concept 21. The method according to concept 20, wherein at least two SEM values measured around 5 10 15 20 25 30 35 40 45 50 55 12 21 EP 4 652 923 A2 22 said anatomical site are recorded at equidistance from said bony prominence. Concept 22. The method according to concept 21, further comprising two or more SEM values are measured at positions that are located on one or moreconcentric circlesabout saidbonyprominence. Claims 1. An apparatus for identifying damaged tissue, the apparatus comprising: (i) one or more coaxial electrodes capable of interrogating tissueat andaroundananatomical site of a patient, wherein each of the one ormore coaxial electrodes are configured to measure a capacitance signal; (ii) a circuit electronically coupled to the one or more coaxial electrodes and configured to con- vert the capacitance signal into a corresponding sub-epidermal moisture (SEM) value; (iii) a processor electronically coupled to the circuit and configured to receive the SEM value; and (iv) a non-transitory computer readablemedium electronically coupled to theprocessorandcom- prising instructions stored thereon that, when executed on theprocessor, perform the steps of: (a) receiving from the processor at least two SEM values measured at and around the anatomical site and their relative measure- ment locations; (b) determining an average SEM value of the at least two SEM values; (c) determining a delta difference between the average SEM value and each of the at least two SEM values; and (d) flagging the relative measurement loca- tions associated with the delta difference greater than a predetermined value as da- maged tissue. 2. The apparatus of claim 1, wherein the instructions further comprise: determining a maximum SEM value from the at least two SEM values; and determining the delta difference between the maximum SEM value and the average SEM value. 3. The apparatus of claim 1, further comprising a sub- strate, and wherein the one or more coaxial electro- des are embedded on a first side of the substrate. 4. The apparatus of claim 3, wherein the substrate is flexible. 5. The apparatus of claim 4, wherein the substrate comprises a material selected from the group con- sisting of Kapton, polyimide, and a combination thereof. 6. The apparatus of claim 3, wherein the substrate is hard. 7. The apparatus of claim 1, further comprising a sec- ond circuit configured to receive and transmit data to a remote device. 8. The apparatus of claim 1, further comprising a tem- perature probe. 9. The apparatus of claim 1, further comprising a con- formal pressure pad configured to provide both sup- port and conformity to a non-planar sensing surface. 10. The apparatus of claim 4, further comprising an insulating cover layer coupled to the flexible sub- strate and configured to act as a barrier between the tissue and the one or more coaxial electrodes. 11. The apparatus of claim 1, wherein each coaxial electrode of the one or more coaxial electrodes comprises a first electrode and a second electrode, and wherein the second electrode is an annular electrode that is disposed around the first electrode. 12. Theapparatus of claim11,wherein the first electrode and the second electrode are configured such that there is an annular gap between the first and second electrodes. 13. The apparatus of claim 12, wherein the annular gap is uniform. 14. The apparatus of claim 1, wherein the anatomical site is selected from the group consisting of a ster- num, a sacrum, a heel, a scapula, an elbow, an ear, and a fleshy tissue. 15. Theapparatusof claim1,wherein thepredetermined value is 0.5. 5 10 15 20 25 30 35 40 45 50 55 13 EP 4 652 923 A2 14 EP 4 652 923 A2 15 EP 4 652 923 A2 16 EP 4 652 923 A2 17 EP 4 652 923 A2 18 EP 4 652 923 A2 19 EP 4 652 923 A2 20 EP 4 652 923 A2 21 EP 4 652 923 A2 22 EP 4 652 923 A2 23 EP 4 652 923 A2 24 EP 4 652 923 A2 25 EP 4 652 923 A2 26 EP 4 652 923 A2 27 EP 4 652 923 A2 28 EP 4 652 923 A2 29 EP 4 652 923 A2 REFERENCES CITED IN THE DESCRIPTION This list of references cited by the applicant is for the reader’s convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard. Patent documents cited in the description • US 62152549

[0001] • US 20140288397 A1, Sarrafzadeh

[0031] 538679\46161944_1.docx IRN: 538679 Title: 用表皮下水分測定確定受損組織的裝置 Abstract: 本公開提供了用於測量患者中的表皮下水分以確定用於臨床干預的受損 組織的設備和計算機可讀介質。本公開還提供了用於確定受損組織的方法。 摘要

Claims

1. An apparatus for identifying damaged tissue, the apparatus comprising: (i) one or more coaxial electrodes capable of interrogating tissue at and around an anatomical site of a patient, wherein each of the one or more coaxial electrodes are configured to measure a capacitance signal; (ii) a circuit electronically coupled to the one or more coaxial electrodes and configured to convert the capacitance signal into a corresponding sub-epidermal moisture (SEM) value; (iii) a processor electronically coupled to the circuit and configured to receive the SEM value; and (iv) a non-transitory computer readable medium electronically coupled to the processor and comprising instructions stored thereon that, when executed on the processor, perform the steps of: (a) receiving from the processor at least two SEM values measured at and around the anatomical site and their relative measurement locations; (b) determining an average SEM value of the at least two SEM values; (c) determining a delta difference between the average SEM value and each of the at least two SEM values; and (d) flagging the relative measurement locations associated with the delta difference greater than a predetermined value as damaged tissue.

2. The apparatus of claim 1, wherein the instructions further comprise: determining a maximum SEM value from the at least two SEM values; and determining the delta difference between the maximum SEM value and the average SEM value.

3. The apparatus of claim 1, further comprising a substrate, and wherein the one or more coaxial electrodes are embedded on a first side of the substrate.

4. The apparatus of claim 3, wherein the substrate is flexible.

5. The apparatus of claim 4, wherein the substrate comprises a material selected from the group consisting of Kapton, polyimide, and a combination thereof.

6. The apparatus of claim 3, wherein the substrate is hard.

7. The apparatus of claim 1, further comprising a second circuit configured to receive and transmit data to a remote device.

8. The apparatus of claim 1, further comprising a temperature probe.

9. The apparatus of claim 1, further comprising a conformal pressure pad configured to provide both support and conformity to a non-planar sensing surface.

10. The apparatus of claim 4, further comprising an insulating cover layer coupled to the flexible substrate and configured to act as a barrier between the tissue and the one or more coaxial electrodes.

11. The apparatus of claim 1, wherein each coaxial electrode of the one or more coaxial electrodes comprises a first electrode and a second electrode, and wherein the second electrode is an annular electrode that is disposed around the first electrode.

12. The apparatus of claim 11, wherein the first electrode and the second electrode are configured such that there is an annular gap between the first and second electrodes.

13. The apparatus of claim 12, wherein the annular gap is uniform.

14. The apparatus of claim 1, wherein the anatomical site is selected from the group consisting of a sternum, a sacrum, a heel, a scapula, an elbow, an ear, and a fleshy tissue.

15. The apparatus of claim 1, wherein the predetermined value is 0.5.

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