Wearable pressure ulcer detection system

Abstract

The present invention relates to a bedsore detection sensor, which includes a pressure sensor that measures pressure based on a change in capacitance due to physical force, a temperature sensor that measures temperature based on a change in electrical conductivity due to electron hopping, and an impedance sensor that includes two electrodes spaced apart from each other and in contact with the skin.

Description

[Technical Field]

[0001] The present invention relates to a wearable pressure ulcer detection sensor Sa and a pressure ulcer detection system comprising the same; and more specifically, to a wearable pressure ulcer detection sensor and a pressure ulcer detection system that can be attached to a subject at risk of developing pressure ulcers, and can prevent pressure ulcers in advance by measuring the risk of pressure ulcer development in real time pressure ulcers including sacs . [Background Art]

[0002] Pressure ulcers are ischemic skin ulcers that occur when pressure is continuously applied to one part of the body, causing blood circulation disorder in that part, resulting in insufficient supply of oxygen and nutrients. Despite being a common disease, the severity of the condition has been greatly overlooked for a long time. This disease, whose progression is divided into four stages, is difficult for doctors to visually identify abnormal symptoms and for patients to feel in the first stage. If the treatment opportunity is missed and the disease progresses beyond the second stage at this time, extensive transplantation of skin and bone is required, and it is a serious and severe disease with a high probability of death due to infectious diseases such as sepsis even after surgery. Currently, methods for preventing pressure ulcers usually depend on the labor of caregivers who continuously change the patient's position, making it difficult to prevent the disease. Once onset, the progression rate is very rapid, accompanied by increased physical and mental pain for the patient and their caregivers, and a rapid increase in medical expenses. Therefore, this is a disease for which there is a strong need for the development of prevention systems and treatment methods.

[0003] In recent years, technologies using the Internet of Things have developed rapidly, but the current situation is that these technologies only remain at the level of collecting pressure distribution of a mat provided with an elastic film using a pressure sensor, or notifying the risk of pressure ulcer development based on the duration of time the patient stays still.

[0004] Therefore, there is a need to develop an early detection system that can monitor the condition of high-risk areas (or areas with pressure ulcer lesions) in real time, especially in the early stages when pressure ulcers are difficult to identify visually, or in abnormal conditions that may progress to pressure ulcers. Furthermore, it can detect the risk of pressure ulcer development and the degree of pressure ulcer progression in real time, and communicate the detection results to the patient, caregiver, guardian, and physician in real time. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Korean Patent Publication No. 2020-0135052 [Patent Document 2] Korean Patent Publication No. 2020-0048938 [Overview of the project] [Problems that the invention aims to solve]

[0006] The object of the present invention is to provide a pressure ulcer sensor capable of bidirectional sensing that can simultaneously measure external stimuli and internal (skin tissue) changes.

[0007] Another object of the present invention is to provide a pressure ulcer sensor that can monitor the condition of a site suspected of developing a pressure ulcer in real time and provide an identification index that enables early diagnosis of pressure ulcers.

[0008] Another object of the present invention is to provide a pressure ulcer sensor that can sense the magnitude of external stimuli causing pressure ulcers and changes in biosignals due to damage to skin tissue simply by attaching it to a site where pressure ulcers are suspected to have developed.

[0009] Another object of the present invention is to provide a pressure ulcer detection system that can remotely monitor the condition of areas at risk of developing pressure ulcers or suspected of developing pressure ulcers in real time. [Means for solving the problem]

[0010] The wearable pressure ulcer detection sensor according to the present invention includes a pressure sensor that measures pressure based on a change in capacitance due to physical force, a temperature sensor that measures temperature based on a change in electrical conductivity due to electron hopping, and an impedance sensor that includes two electrodes spaced apart from each other and in contact with the skin.

[0011] In a wearable pressure ulcer detection sensor according to one embodiment of the present invention, the pressure sensor may include a polymer gel electrolyte capacitor.

[0012] In a wearable pressure ulcer detection sensor according to one embodiment of the present invention, the temperature sensor may include a conductive polymer matrix and carbon nanostructures dispersed and incorporated in the matrix.

[0013] In a wearable pressure ulcer detection sensor according to one embodiment of the present invention, the carbon nanostructure may include carbon nanotubes, graphene, or a mixture thereof.

[0014] In a wearable pressure ulcer detection sensor according to one embodiment of the present invention, the two electrodes of the impedance sensor may each be a composite of an insulating elastic material and a conductive nanowire.

[0015] A wearable pressure ulcer detection sensor according to one embodiment of the present invention may further include a fabric substrate on which wiring is formed on one surface, and the pressure sensor, the temperature sensor, and the impedance sensor may be arranged spaced apart on one surface of the fabric substrate.

[0016] A wearable pressure ulcer detection sensor according to one embodiment of the present invention may further include a wettable polymer foam covering one surface of the fabric substrate, the wettable polymer foam may include through holes formed such that a pressure sensor, a temperature sensor, and an impedance sensor are exposed on its surface.

[0017] The present invention includes a wearable pressure sore detection system including the above-described wearable pressure sore detection sensor.

[0018] The wearable pressure sore detection system according to the present invention comprises: the above-described wearable pressure sore detection sensor; a microprocessing unit electrically connected to the pressure sore detection sensor, which receives input of sensing values from a pressure sensor, a temperature sensor, and an impedance sensor of the pressure sore detection sensor, and calculates pressure ulcer indicators including the pressure applied to the body of a user attached with the pressure sore detection sensor, skin temperature value, and tissue impedance value; and a wireless communication unit that transmits the pressure ulcer indicators calculated by the microprocessing unit to a terminal device via wireless communication.

[0019] In the pressure sore detection system according to an embodiment of the present invention, the microprocessing unit and the wireless communication unit may be provided on a flexible printed circuit board (PCB).

[0020] In the pressure sore detection system according to an embodiment of the present invention, the wireless communication may include short-range wireless communication including Wi-Fi (registered trademark) or Bluetooth (registered trademark). Effects of the Invention

[0021] The pressure sore detection system according to the present invention uses a pressure sensor, a temperature sensor, and an impedance sensor that ensure wearable characteristics, and provides not only the pressure applied to a site where pressure ulcer development is suspected, but also the skin temperature and the impedance of internal tissue at the site where pressure ulcer development is suspected, thereby having the advantage that it is possible to detect in advance whether pressure ulcers have occurred and the risk of pressure ulcer development at a time point when it is difficult to visually determine the onset of pressure ulcers. Brief Description of the Drawings

[0022] [Figure 1] It is a diagram showing the configuration of a pressure sore detection sensor according to an embodiment of the present invention. [Figure 2] It is a diagram showing the configuration of a pressure sore detection system according to an embodiment of the present invention. [Figure 3] FIG. 1 is a diagram illustrating the configuration of a wireless communication unit and a microprocessing unit integrated on a flexible PCB in a pressure ulcer detection system according to an embodiment of the present invention. MODES FOR CARRYING OUT THE INVENTION

[0023] Hereinafter, the wearable pressure ulcer detection sensor of the present invention will be described in detail with reference to the accompanying drawings. The drawings introduced below are provided as examples to fully convey the concept of the present invention to those skilled in the art. Therefore, the present invention is not limited to the drawings presented below, and may be embodied in other forms. The drawings presented below may be exaggerated for clarity of the concept of the present invention. Unless otherwise defined, the technical and scientific terms used herein have the meanings commonly understood by a person having ordinary knowledge in the technical field to which the present invention pertains. Descriptions of well-known functions and configurations that may obscure the gist of the present invention in the following description and the accompanying drawings are omitted.

[0024] Also, the singular forms used in the specification and the appended claims are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0025] In this specification and the appended claims, terms such as first and second are used for the purpose of distinguishing one component from another, and are not intended to be limiting.

[0026] In this specification and the appended claims, terms such as "comprising" or "having" mean that the features or components described in the specification are present, and unless otherwise limited, do not preclude the possibility of adding one or more other features or components in advance.

[0027] In this specification and the appended claims, when a part such as a film (layer), region, or component is located on another part, this includes not only cases where it is in contact with and directly above the other part, but also cases where another film (layer), region, component, etc. is interposed between them.

[0028] The wearable pressure ulcer detection sensor according to the present invention includes a pressure sensor that measures pressure based on a change in capacitance due to physical force, a temperature sensor that measures temperature based on a change in electrical conductivity due to electron hopping, and an impedance sensor that includes two electrodes spaced apart from each other and in contact with the skin.

[0029] The wearable pressure ulcer detection sensor according to the present invention has the advantage of being a bidirectional sensor that can simultaneously detect not only external stimuli, including external pressure applied to the skin, but also changes in biological signals, including temperature and impedance, which change due to damage (abnormality) to skin tissue, by including a pressure sensor, a temperature sensor, and an impedance sensor. In other words, it can simultaneously detect external stimuli and internal biological changes.

[0030] Furthermore, the wearable pressure ulcer detection sensor according to the present invention provides an indicator that can determine the degree of damage (abnormality) to skin tissue by detecting changes in temperature and impedance in the area (skin area) where pressure ulcers are suspected to have developed. In addition, by sensing and providing the pressure applied to the area where pressure ulcers are suspected to have developed, the user (user of the pressure ulcer detection sensor), guardian, or medical staff can recognize and judge the degree of risk of pressure ulcer development before pressure ulcers develop. Moreover, even if the user has already developed pressure ulcers, the user, guardian, or medical staff can recognize and judge the degree and rate of progression (treatment) of the lesion at the site of the pressure ulcer.

[0031] Furthermore, the wearable pressure ulcer detection sensor according to the present invention is highly advantageous in pressure ulcer detection because, since the pressure sensor calculates pressure based on the change in capacitance due to physical force (pressure applied from the outside), it can measure pressure in the form of an extremely thin film, ensuring wearable characteristics, and can accurately measure the level of pressure generated by the weight of the human body while lying down.

[0032] Since temperature sensors measure temperature based on changes in electrical conductivity caused by electron hopping, they can measure temperature in the form of extremely thin films, thus ensuring wearable characteristics. Similarly, impedance sensors measure the impedance of skin tissue using two electrodes positioned spaced apart and in contact with the user's skin, allowing for the use of thin-film electrodes to ensure wearable characteristics.

[0033] In one advantageous example, the pressure sensor may include a polymer gel electrolyte capacitor. The polymer gel electrolyte capacitor may include a first electrode that contacts the user's skin, a polymer gel electrolyte, and a second electrode that faces the first electrode across the polymer gel electrolyte. As is well known, liquid electrolytes, inorganic electrolytes, or polymer-based solid electrolytes are used as the electrolyte in thin-film capacitors. Liquid electrolyte-based capacitors are unsuitable because they are difficult to integrate into pressure ulcer sensors, have poor stability during use, and have inferior flexibility compared to inorganic electrolytes. In thin-film capacitors, polymer-based solid electrolytes can be broadly classified into solid polymer electrolytes, gel-type polymer electrolytes, and polyvalent electrolytes. Among these, gel-type polymer electrolytes do not leak and can achieve the highest ionic conductivity among solid electrolytes, but they have the disadvantage of weak mechanical properties.

[0034] An advantageous example of the present invention is a pressure ulcer detection sensor that takes advantage of the shortcomings of such gel-type polymer electrolyte-based capacitors. Specifically, it ensures the flexible properties of the gel-type polymer electrolyte and utilizes the fact that ions pass through the internal ion pump of the electrolyte due to the pressure caused by the weight of the human body, thereby changing the capacitance, to measure the pressure applied to a site where pressure ulcers are suspected to be developing.

[0035] When pressure is sensed using a polymer gel electrolyte capacitor, a highly sensitive pressure sensor can be realized over a wide pressure range, including the 4-13 kPa (30-100 mmHg) pressure range known to be applied to the skin when lying in bed, by adjusting the elastic modulus of the polymer gel electrolyte (gel-type polymer electrolyte). As a practical example, the elastic modulus (at room temperature) of the polymer gel electrolyte in the polymer gel electrolyte capacitor may be at a very low level of 0.01-1.00 kPa so that the capacitance changes sensitively in response to pressure over the 4-13 kPa pressure range.

[0036] As is well known, polymer gel electrolytes can be acidic or basic electrolytes, and consist of polymers such as PEO (poly(ethylene oxide)), PA (poly(acrylate)), PVA (poly(vinyl alcohol)), and PAA (poly(acrylic acid)), salts such as potassium hydroxide, sulfuric acid, phosphoric acid, and perchloric acid, and solvents such as water. The elastic modulus of the polymer gel electrolyte can be appropriately adjusted by changing the content of the electrolyte components or the specific substances.

[0037] The two electrodes (first electrode and second electrode) of the polymer gel electrolyte capacitor can be any electrodes commonly used in solid capacitors. Examples include, but are not limited to, transparent conductive oxides such as indium tin oxide, nanowire networks such as silver nanowires, conductive two-dimensional carbon structures such as graphene, conductive one-dimensional carbon structures such as carbon nanotubes, activated carbon, and conductive polymers such as PEDOT:PSS (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)). Furthermore, the specific dimensions of the polymer gel electrolyte capacitor only need to be sufficient to smoothly measure the pressure applied to the area suspected of developing a pressure ulcer. Practical examples include a width of 1 mm to 5 cm, a horizontal width of 1 mm to 5 cm, and a polymer gel electrolyte thickness of 10 to 100 μm, but are not limited to these.

[0038] A temperature sensor can monitor changes in body temperature in areas suspected of developing pressure ulcers due to abnormalities or inflammation of skin tissue. In one advantageous example, the temperature sensor may include a conductive polymer matrix and carbon nanostructures dispersed and incorporated in the matrix. Substantially, the temperature sensor may include a thin film of a composite comprising a conductive polymer matrix and carbon nanostructures dispersed and incorporated in the conductive polymer matrix.

[0039] The conductive polymer in the conductive polymer matrix may be one or more selected from polyacetylene-based, polyaniline-based, polypyrrole-based, and polythiophene-based polymers, but is not limited thereto. As a practical example, conductive polymers include one or more selected from polyacetylene (PA), polyaniline (PANI), polypyrrol (PPy), polythiophene (PT), polyethylenedioxythiophene (PEDOT), polyisothianaphthene (PITN), polyphenylene vinylene (PPV), polyphenylene (PPE), polyphenylene sulfide (PPS), and polysulfur nitride (PSN).

[0040] The carbon nanostructure may be a conductive carbon nanostructure, which may include, but is not limited to, carbon nanotubes, graphene (including reduced graphene oxide (RGO)), or mixtures thereof.

[0041] In the aforementioned composite thin film (composite thin film), charge transfer occurs through electron hopping at the composite interface. As the temperature increases, the amount of electrons at the interface increases, and the resistance decreases. Therefore, by measuring the electrical properties of the composite thin film, it is possible to sense the temperature of a site suspected of developing a pressure ulcer. Needless to say, these electrical properties may include electrical conductivity and electrical resistance.

[0042] Considering the normal body temperature and variable abnormal body temperature, a temperature range of 35-45°C can be considered the effective temperature range for high-precision detection by the temperature sensor. The sensing sensitivity of the temperature sensor within this effective temperature range can be ensured by adjusting the interface area between the conductive polymer and the carbon nanostructure in the composite.

[0043] Within the effective temperature range, the composite thin film preferably contains carbon nanotubes as carbon nanostructures so that its electrical properties change sensitively in response to temperature changes, and the weight ratio of the conductive polymer matrix to the carbon nanotubes is preferably 1:0.3 to 0.5. However, since temperature sensing is not impossible even outside this range, the present invention is not limited by the specific composition or materials of the composite thin film.

[0044] The specific dimensions of the composite thin film only need to be sufficient to allow for smooth measurement of the temperature of the area suspected of developing a pressure ulcer. As a practical example, the specific dimensions of the composite thin film may be a width of 0.5 mm to 2.0 mm, a transverse width of 0.5 mm to 1.0 mm, and a thickness of 100 to 300 μm, but are not limited to these dimensions.

[0045] An impedance sensor may include two electrodes spaced apart from each other, and each of the two electrodes may be a composite of an insulating elastic material and a conductive nanowire. Specifically, the two electrodes may each be a composite including an insulating elastic material substrate and conductive nanowires dispersed and bonded to the insulating elastic material substrate to form a network. In this case, it goes without saying that the network of conductive nanowires can mean a structure in which a continuous current transfer path is formed by bonding or contact between conductive nanowires. The insulating elastic material may be a curable resin with high flexibility and elasticity, and examples include, but are not limited to, siloxane-based resins, olefin-based elastic resins, or polyurethane-based resins. The conductive nanowire may be a metallic nanowire, and examples of metallic nanowires include, but are not limited to, nanowires of silver, gold, copper, nickel, or mixtures thereof, or core-shell nanowires thereof.

[0046] Conventional hydrogel-based electrodes are prone to moisture evaporation, and their adhesion decreases due to contamination of the electrode surface, making long-term use difficult. Furthermore, they lack flexibility and elasticity, limiting their suitability as wearable sensors that require long-term adhesion. In contrast, the electrode of an impedance sensor according to one embodiment is based on a composite of an insulating elastic material and conductive nanowires, ensuring excellent flexibility. This allows it to adhere stably and firmly to areas suspected of developing pressure ulcers due to the weight of a sleeping person, and maintains a stable contact state between the metal nanowire and the skin over a long period.

[0047] The specific dimensions of the two electrodes of the impedance sensor should be such that they can smoothly measure the impedance of the skin tissue in the area where pressure ulcers are suspected. For example, the width and length of the electrodes may be in the range of 1 mm to 1 cm, and the distance between the two electrodes may be in the range of 0.5 cm to 5 cm, but this is not limited to these dimensions.

[0048] The impedance of skin tissue is at the level of several MΩ in healthy skin and at the level of tens of kΩ in damaged skin, with lower impedance indicating more severe damage. Therefore, by measuring the impedance of skin tissue with an impedance sensor, it is possible to detect the presence and extent of skin tissue damage in areas suspected of developing pressure ulcers. In this case, the range of AC frequencies applied to the two electrodes to measure impedance is 10 0 ~10 6 The frequency is at the Hz level, the magnitude of the AC voltage is at the mV level, specifically 2 to 10 mV, and the AC may, but is not limited to, a sine wave.

[0049] Furthermore, by applying an alternating current voltage to the two electrodes of the impedance sensor, the impedance of the area (skin tissue) suspected of developing a pressure ulcer can be measured, and at the same time, a minute electrical stimulus can be applied to the area suspected of developing a pressure ulcer.

[0050] A pressure ulcer detection sensor according to one embodiment may further include a fabric substrate on which wiring is formed on one surface. The fabric substrate on which the wiring is formed can serve as a platform on which the above-mentioned pressure sensor, temperature sensor, and impedance sensor are integrated.

[0051] Furthermore, a pressure ulcer detection sensor according to one embodiment may further include a wet polymer foam covering one surface of a fabric substrate, the wet polymer foam may include through-pores formed so that a pressure sensor, a temperature sensor, and an impedance sensor are exposed on its surface.

[0052] Figure 1 shows an example of a configuration diagram of a pressure ulcer detection sensor according to one embodiment of the present invention.

[0053] As shown in the example in Figure 1, the pressure ulcer detection sensor may include a fabric substrate 100 on which wiring 110 is formed, a pressure sensor 200, a temperature sensor 300, impedance sensors 410-460, and a wettable polymer foam 500 on which through-holes 510 are formed. The fabric substrate 100 has flexible properties and conformal properties that protect the sensors from moisture, dust, chemicals, etc., and can provide a platform with excellent breathability. The fabric substrate 100 is provided with wiring 110 formed using conductive ink or the like, and the pressure sensor 200, temperature sensor 300, and impedance sensors 410-460 can each be electrically connected to the outside of the fabric substrate 100 via such wiring.

[0054] The wettable polymer foam 500 can absorb sweat and bodily fluids, thereby maintaining the sensitivity of each integrated sensor (pressure sensor 200, temperature sensor 300, and impedance sensors 410-460). The wettable polymer foam 500 may contain moisture and only needs to contain biocompatible substances. As an example, the wettable polymer foam may be, but is not limited to, a foam of a hydrophilic polymer such as polyvinyl alcohol, polyethylene glycol, polyethylene oxide, polyvinyl acrylic acid, polymethacrylic acid, or polyurethane, or a foam of a mixture of a hydrophilic polymer and cellulose esters or cellulose ethers such as carboxymethylcellulose, carboxymethyl hydroxyethylcellulose, methylcellulose, hydroxyethyl methylcellulose, hydroxypropyl methylcellulose, ethyl hydroxyethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, or hydroxyethyl hydroxypropylcellulose.

[0055] The wet polymer foam 500 may have a shape and size corresponding to the fabric substrate 100 and may include through-holes 510 formed so that the pressure sensor 200, temperature sensor 300, and impedance sensors 410-460 integrated into the fabric substrate 100 are exposed on its surface. This allows each of the sensors 200, 300, and 410-460 integrated into the fabric substrate 100 to be exposed through the through-holes in the wet polymer foam 500 and to come into direct contact with the user's skin. Thus, in actual use of the pressure ulcer detection sensor, the wet polymer foam 500 is the side that comes into contact with the human body, and the fabric substrate 100 is the layer that covers the skin.

[0056] Furthermore, as shown in the example in Figure 1, the impedance sensor may be provided with two or more units, each unit for impedance measurement consisting of two electrodes (410-420, or 430-440, or 450-460) to which a voltage transmitted via wiring 110 formed on the fabric substrate 100 is applied. The example in Figure 1 is an example provided with three units. When the impedance sensor includes two or more units, abnormalities in skin tissue can be effectively detected even in areas where the development of a large pressure ulcer is suspected. Needless to say, the number of units provided, the position of each unit, and the isolation distance between the two electrodes in each unit can be appropriately adjusted, taking into consideration the specific area and shape of the area where the development of a pressure ulcer is suspected.

[0057] The present invention includes a wearable pressure ulcer detection system that includes the above-described wearable pressure ulcer detection sensor.

[0058] The wearable pressure ulcer detection system according to the present invention may include the above-described wearable pressure ulcer detection sensor, a microprocessing unit electrically connected to the pressure ulcer detection sensor, which receives sensing values ​​from the pressure sensor, temperature sensor, and impedance sensor of the pressure ulcer detection sensor and calculates a pressure ulcer index including the pressure applied to the user's body to which the pressure ulcer detection sensor is attached, skin temperature value, and tissue impedance value, and a wireless communication unit which transmits the pressure ulcer index calculated by the microprocessing unit to a terminal device via wireless communication.

[0059] Advantageously, the microprocessing unit and the wireless communication unit may be mounted on a flexible printed circuit board (PCB) and electrically connected to the wearable pressure ulcer detection sensor described above.

[0060] Conventional wearable sensors are typically connected to external devices via wiring for data processing and transmission, which leads to problems such as reduced comfort and limited startup time.

[0061] However, as shown in the example in Figure 2, the wearable pressure ulcer detection system according to the present invention integrates a microprocessing unit for data processing and a wireless communication unit for wireless communication on a flexible PCB, and connects to the pressure ulcer detection sensor 1000 via flexible wiring. Therefore, the flexible PCB 2000, in which the microprocessing unit and wireless communication unit are integrated, can be positioned around the human body (user), thus preventing the feeling of a foreign object during use and not impairing startup.

[0062] Figure 3 shows an example of a configuration diagram of a flexible PCB that integrates a microprocessing unit and a wireless communication unit.

[0063] As shown in the example in Figure 3, the microprocessing unit may include a micro-impedance analyzer 740 for detecting changes in impedance, a low-pass filter 720 for signal filtering, and an AC chip 750 for detecting changes in temperature and pressure. The outputs of these can be converted into digital signals via a microcontroller 730. The sensors are powered via a coupling section 710, and the sensed values ​​are output. In detail, the temperature sensor detects temperature changes based on changes in the resistance of a composite thin film containing a conductive polymer matrix and carbon nanostructures dispersed and incorporated in the matrix, and can be controlled and measured using a digital temperature sensor module controller such as ON Semiconductor's NCT75 controller. The pressure sensor detects pressure based on changes in capacitance and can be controlled and measured using an electrostatic touchscreen controller such as MICROCHIP's CAP1203 controller. The finally measured signals are transmitted to the microcontroller 730, where they can be calculated into the final signal and converted into a digital signal.

[0064] Therefore, the signals digitally output by the microcontroller 730 may include the pressure applied to the area suspected of developing a pressure ulcer, the skin temperature of the area suspected of developing a pressure ulcer, and the impedance value of the internal skin tissue of the area suspected of developing a pressure ulcer. The pressure applied to the body, the skin temperature value, and the tissue impedance value are indicators (pressure ulcer indicators) that can medically determine the risk of pressure ulcer development and the degree of pressure ulcer progression, and such pressure ulcer indicators may be transmitted via wireless communication to terminal devices of relevant parties such as physicians, users of the pressure ulcer detection sensor, and guardians.

[0065] The wireless communication unit may include a transmitter 770 or a transreceiver 770, and an antenna 780 that transmits or receives electromagnetic waves of a certain frequency. The wireless communication may be short-range wireless communication such as Bluetooth® or Wi-Fi®. Low-power Bluetooth can communicate wirelessly even at distances of 10m or more, and when using a mesh Bluetooth system, one device can connect to hundreds or more Bluetooth® devices at once, allowing pressure ulcer indicators to be transmitted to terminal devices of various stakeholders.

[0066] In this case, if the wireless communication unit includes a transceiver, it goes without saying that it can receive signals transmitted from terminal devices such as doctors, users of the pressure ulcer detection sensor, and guardians, and based on the received signals, it can control the on / off state of the pressure ulcer detection sensor, the transmission interval of pressure ulcer indicators, and the selective transmission of only specific indicators from among various pressure ulcer indicators. Furthermore, it goes without saying that the flexible PCB 600 may be equipped with a microprocessing unit, a wireless communication unit, and a power source to supply power to the pressure ulcer detection sensor, such as a battery 760.

[0067] Although the present invention has been described above with reference to specific details, limited embodiments, and drawings, these are provided only for a more general understanding of the invention, and the invention is not limited to the above embodiments. A person with ordinary skill in the art to which the invention belongs can make various modifications and variations from this description.

[0068] Therefore, the concept of the present invention should not be limited to the embodiments described, and it can be said that not only the appended claims, but also all equivalent or equivalent variations thereof, fall within the scope of the concept of the present invention.

Claims

1. A wearable pressure ulcer detection sensor includes a pressure sensor for measuring pressure, a temperature sensor for measuring temperature, and an impedance sensor including two electrodes spaced apart from each other and in contact with the skin. A microprocessing unit is electrically connected to the wearable pressure ulcer detection sensor, receives sensing values ​​from the pressure sensor, temperature sensor, and impedance sensor of the wearable pressure ulcer detection sensor, and calculates a pressure ulcer index including the pressure applied to the user's body to which the wearable pressure ulcer detection sensor is attached, skin temperature value, and tissue impedance value. A wearable pressure ulcer detection system comprising: a wireless communication unit that transmits pressure ulcer index calculated by the microprocessing unit to a terminal device via wireless communication, A wearable pressure ulcer detection system in which the on / off state of the wearable pressure ulcer detection sensor, the transmission interval of the pressure ulcer indicator, and the selective transmission of only specific indicators among the pressure, temperature, and tissue impedance values ​​are controlled based on signals transmitted from the terminal device.

2. The wearable pressure ulcer detection system according to claim 1, wherein the pressure sensor of the wearable pressure ulcer detection sensor includes a polymer gel electrolyte capacitor.

3. The wearable pressure ulcer detection system according to claim 1, wherein the temperature sensor of the wearable pressure ulcer detection sensor includes a conductive polymer matrix and carbon nanostructures dispersed and incorporated in the conductive polymer matrix.

4. The wearable pressure ulcer detection system according to claim 3, wherein the carbon nanostructure comprises carbon nanotubes, graphene, or a mixture thereof.

5. The wearable pressure ulcer detection system according to claim 1, wherein the two electrodes of the impedance sensor of the wearable pressure ulcer detection sensor are each a composite of an insulating elastic material and a conductive nanowire.

6. The wearable pressure ulcer detection sensor further includes a fabric substrate on which wiring is formed on one surface, The wearable pressure ulcer detection system according to claim 1, wherein the pressure sensor, the temperature sensor, and the impedance sensor are arranged spaced apart on one surface of the fabric substrate.

7. The wearable pressure ulcer detection sensor further comprises a wettable polymer foam covering one surface of the fabric substrate, The wearable pressure ulcer detection system according to claim 6, wherein the wet polymer foam of the wearable pressure ulcer detection sensor includes through holes formed such that a pressure sensor, a temperature sensor, and an impedance sensor are exposed on its surface.

8. The wearable pressure ulcer detection system according to claim 1, wherein the microprocessing unit and the wireless communication unit are provided on a flexible printed circuit board.

9. The wearable pressure ulcer detection system according to claim 1, wherein the wireless communication includes short-range wireless communication.

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