Mobile pressure measuring unit for measuring the pressure of a medical compression bandage on an extremity

Abstract

The present invention relates to a mobile pressure measuring unit for measuring the pressure of a medical compression bandage on an extremity, such as a leg. In particular, the mobile pressure measuring unit is suitable for measuring the pressure during a compression treatment. The mobile pressure measuring unit contains two pressure sensors and supports the wireless transmission of measured values to a reader. A bandage containing the pressure measuring unit is also described. A further component of the invention is a method for producing the mobile pressure measuring unit.

Description

[0001] Mobile pressure measuring unit for measuring the pressure of a medical compression bandage on an extremity

[0002] Description

[0003] Technical field of the invention

[0004] The present invention relates to a mobile pressure measuring unit for measuring the pressure exerted by a medical compression bandage on an extremity. In particular, the mobile pressure measuring unit is suitable for measuring pressure during compression therapy. Furthermore, it is used in sports to accelerate regeneration and increase performance through compression.

[0005] Background of the invention

[0006] Human tissue is primarily supplied by blood. This circulates in arteries and veins. The risk of blood congestion is higher in the venous system than in the arteries because veins have lower blood pressure. To compensate for this, veins have venous valves that ensure the return of blood against gravity. This process is also supported by muscle contractions during movement (the venous-muscle pump).

[0007] However, these natural mechanisms can be disrupted or overloaded for various reasons. Risk factors include smoking, diabetes, advanced age, prolonged sitting or standing, and lack of exercise.

[0008] If venous congestion occurs over a longer period of time, pathological changes in the tissue result. Initially, the vessel walls are pushed apart. Fluid accumulation (edema) occurs. Blood cells clump together (tendency to thrombosis) and trigger an inflammatory reaction. The inflammation increases the permeability of the vessel walls. Blood components and cells leave the venous vessels and enter the surrounding tissue, where dysfunction occurs. At the same time, insufficient blood flow leads to inadequate supply. The resulting long-term condition is known as chronic venous insufficiency. As the condition progresses, the affected skin areas become darkened (hyperpigmentation), reddened, and eczema develop. In the late stages, ulcers form, ultimately leading to an open leg ulcer (ulcus cruris).Due to poor circulation and lack of healing, this wound carries a high risk of subsequent infections and associated complications. The quality of life of those affected is significantly reduced.

[0009] Compression therapy is an established medical procedure primarily used in phlebology (the study of veins). It increases or facilitates venous return by applying external pressure to the tissue, thereby reducing or, ideally, eliminating venous congestion in the limbs (primarily the legs). Compression therapy is also used for congestion in the lymphatic system (lymphatic edema).

[0010] Textile materials are used to establish and maintain the necessary compression. A distinction can be made between medical compression bandages and compression stockings. While compression stockings are generally used for prevention and relapse prevention, compression bandages have proven effective during acute illness. These create a stiffer compression pressure than compression stockings. However, even with compression stockings, it is possible to adjust or increase the compression pressure by pulling two layers (overstocking and understocking) on ​​top of each other.

[0011] Adaptive compression bandages are also available, with adjustable width and pressure via Velcro fasteners. There is also special compression clothing for athletes designed to improve blood circulation and thus accelerate recovery.

[0012] Compression bandages are available in various designs for compression therapy using bandages. Choosing the right compression bandage can be crucial to the success of the therapy. First of all, the various products differ in terms of their resting and working pressure. While the resting pressure is already effective while lying down, the working pressure is created during movement through the interaction of muscle activity and the bandage as a counterforce (venous-muscle pump).

[0013] Accordingly, the various bandages differ in their extensibility. So-called short-stretch bandages have only a slight extensibility, resulting in bandages with low elasticity. They combine high working pressure with low resting pressure. Short-stretch bandages are primarily used during the initial treatment phase (decongestion phase). In contrast, long-stretch bandages have a high extensibility, resulting in low working pressure with high resting pressure. Zinc paste bandages, on the other hand, harden when they dry after being applied while moist. This hardening creates the compression pressure. If the leg circumference decreases, the pressure decreases accordingly, necessitating frequent bandage changes.

[0014] Multi-component systems use sets consisting of two to four components. Padding, compression, and fixation bandages are used to compensate for anatomical irregularities and adjust the ideal pressure.

[0015] Generally, bandages can be cohesive, so they adhere to themselves, thus facilitating the application and fixation of the pressure bandage. A distinction is made between single-sided and double-sided cohesive bandages.

[0016] Many bandages can be sterilized (steam sterilization), which makes them easier to use on existing wounds.

[0017] Inappropriate compression stockings or improper wrapping can cause skin damage, resulting in pressure sores, constrictions, or necrosis. Nerve damage or deep vein thrombosis can also develop. Compression materials applied incorrectly or too tightly are particularly problematic in cases of existing nerve damage, which often occurs in diabetics along with leg ulcers. In such cases, the patient feels only limited or no sensation of the tissue damage caused by incorrect compression.

[0018] Compression therapy is only successful if the pressure is set within a specified pressure interval and then maintained for a sufficient period of time. In routine medical practice, the pressure during bandaging is usually only estimated. This often leads to pressure values ​​that lie outside the optimal pressure interval.

[0019] However, even if the pressure has been correctly adjusted, it can change over time. Reasons for this include a loss of tissue recovery within the bandage (short-stretch bandages are particularly susceptible to this), a reduction in tissue volume (reduction of swelling or edema), and patient movements, which can cause the bandage to slip.

[0020] To set the correct pressure and detect pressure deviations, several technical aids have been proposed. For example, WÖ2014066077A1 describes a system for pressure measurement in compression therapy that, in addition to a pressure measurement unit, features a posture sensor for recording the patient's posture. Pressure and posture data are processed in an evaluation unit. The evaluation unit is attached outside the compression textile. However, this limits its suitability for everyday use and further restricts the patient (e.g., while sleeping). Furthermore, the evaluation unit requires a continuous power supply, which requires recharging or battery replacement over time.

[0021] WO2016073777A1 describes a system for pressure measurement in compression therapy that requires one or more network devices ("data collection / transmitter nodes"). The disadvantage of this approach is that the electronic components are unprotected. This applies not only to components attached to the outside of the compression bandage, but also to materials worn underneath the bandage, where they are exposed to compression pressure. At the same time, the components pressed into the skin by the compression pressure can be uncomfortable for the patient—especially when worn for long periods—and reduce the patient's acceptance of the therapy.

[0022] In addition, while compression bandages are highly breathable, they still limit the body's heat loss. Components placed between the compression bandage and the skin inhibit the release of sweat, which contains electrically conductive ions. Excessive sweat can impair the functionality or accuracy of electronic components. In the presence of an existing leg ulcer, wound secretion may also be present in addition to sweat. Additional stress on the components occurs when patients place their body weight on them—for example, while sleeping.

[0023] US2017100300A1 describes a system for measuring pressure during tissue compression during sports training. This system requires a transmitter / receiver unit that is dependent on a power supply. The transmitter / receiver unit is attached to the leg using a cord and a twist-lock system. This approach also fails to overcome the aforementioned disadvantages. The object of the present invention is to provide a system for measuring and monitoring compression pressure that can be applied quickly and easily, is insensitive to external influences, ensures a high level of comfort even during sleep, and is material- and space-saving.

[0024] Summary of the invention

[0025] The invention relates to a compact and mobile pressure measuring unit for measuring compression pressure, which does not require its own power supply. The invention also includes a method for manufacturing the mobile pressure measuring unit and a set for use in compression therapy.

[0026] The mobile pressure measuring unit is suitable for measuring the contact pressure exerted by a medical compression bandage on a patient's extremity or tissue. The pressure measuring unit comprises the following components: a) a gas-tight housing having a flexible dome and a gas-filled cavity within it, wherein the dome is suitable for being applied to the skin of a patient to absorb the contact pressure of the bandage applied over the housing, and wherein the dome is preferably flat; b) a first pressure sensor, which is located outside the gas-filled cavity and which communicates with the atmospheric air, for measuring the outside air pressure, wherein the pressure sensor is attached to the outside of the housing or is at least partially embedded in the housing; c) a second pressure sensor, which is located inside the gas-filled cavity and which communicates with it;for measuring the internal air pressure in the gas-filled cavity, d) a printed circuit board which is present in the gas-filled cavity and comprises a passive RFID transponder, wherein the printed circuit board is electrically connected to the first and second pressure sensors, and wherein, using an RFID reader, pressure measurements can be carried out by the pressure sensors and the data thus determined can be read out wirelessly.

[0027] The technical solution according to the invention offers a number of advantages. These include the absence of cables outside the housing of the pressure measuring unit. Eliminating such cables not only increases wearing comfort. It also simplifies and speeds up application, as no cables need to be routed through the compression bandage's windings and avoids the risk of cables being pressed into the skin by the bandage. In this sense, the invention includes a mobile pressure measuring unit in which no cables are located outside the housing. Preferably, all cables associated with the mobile pressure measuring unit and / or all cables operatively connected to the mobile pressure measuring unit are located within the housing.

[0028] Furthermore, the electronic components are largely protected from external influences such as sweat, wound secretions, compression pressure, and body weight by the surrounding housing. According to a preferred embodiment, the mobile pressure measuring unit is splash-proof and can therefore also be disinfected if necessary. Splash-proof protection can be achieved by using waterproof materials for the housing (e.g., PU) and directly or indirectly shielding the first pressure sensor with an air-permeable but waterproof membrane (e.g., ePTFE). Sensors that can measure humidity in addition to pressure are generally more resistant to water than conventional pressure sensors. Sensors that can be used to determine water pressure while diving ensure particularly high water resistance.For example, the sensor element can be separated from the measuring medium by a metal membrane, thereby protecting it from external influences. Another option is to use a gel-filled pressure sensor. The gel fills the cavities inside the sensor and provides a certain degree of protection against the ingress of water and particles. Such sensors can be installed as the first pressure sensor in the mobile pressure measurement unit. This also has the advantage of being insensitive to sweat, which can be released from the skin beneath a compression textile or beneath the mobile pressure measurement unit.

[0029] By eliminating the need for a dedicated power supply, the pressure measurement unit is ready for immediate use without the need to charge a rechargeable battery or insert batteries. Discharge during operation is eliminated. At the same time, this allows for a very compact design. This allows the system to be completely installed beneath the compression garments and held in place by them, making it invisible from the outside.

[0030] Furthermore, sufficient quantities of the pressure measuring unit can be kept in stock in a space-saving manner. Since discharge is impossible, storage time is virtually unlimited. The production of the pressure measuring unit according to the invention is very material-efficient and therefore cost-effective and sustainable.

[0031] Thanks to its compact design, the pressure measurement unit is very lightweight, so it doesn't restrict the wearer's mobility. Because it also maintains mobility, the mobile pressure measurement unit can be worn with sports compression clothing, both during physical activity and afterward, to accelerate muscle recovery through targeted compression.

[0032] Detailed description of the invention

[0033] In the context of the present invention, the term "mobile" means that the pressure measurement unit can be used anywhere and worn for several days at a time. The wearer's mobility is maintained.

[0034] "Pressure measuring unit" means a device capable of measuring compression pressure during compression therapy. Thus, the pressure measuring unit is a compression pressure measuring unit.

[0035] The term "contact pressure" is understood in the broadest sense to refer to the pressure exerted by the compression textile (e.g., the medical bandage) on human tissue. In the context of the present invention, "contact pressure" can refer to the pressure with which the compression textile presses the pressure measuring unit against the wearer's skin, and which is detected and quantified by the pressure measuring unit.

[0036] The term "tissue" refers specifically to human tissue that is prone to edema in cases of venous congestion. This primarily refers to the connective tissue of the extremities, with the legs being more frequently affected than the arms. In the context of accelerated regeneration, "tissue" also includes muscle tissue.

[0037] "Bandage" refers to a compression bandage. Compression bandages are also referred to as compression bandages. Various types of compression bandages are listed and explained in this document.

[0038] The term "gas-tight" refers to the housing of the pressure measurement unit and means that the gas contained within the housing does not escape below the maximum pressure applicable for compression therapy (approximately 80 mmHg). This gas can be a gas mixture, such as air.

[0039] "Flexible" means that a material is reversibly deformed under the action of a mechanical force (e.g. a pressure of up to 200 mmHg) without stretching or compressing, and that the material in question returns to its original shape after the force has been removed.

[0040] "Electrically connected" means that one or more electrical conductors are located between the connected elements, allowing electrons to pass through the conductor from one element to another. Such a conductor can also be a semiconductor. Two components that are electrically connected can either be directly plugged in (e.g., a pressure sensor can be plugged directly onto a circuit board) or connected via cables.

[0041] "RFID" stands for "radio-frequency identification." This technology enables contactless data exchange between an RFID transponder and an RFID read / write device. To do this, the RFID read / write device creates a magnetic or electromagnetic field, which generates an electric current at the RFID transponder's passive antenna.

[0042] "NFC" stands for "near field communication." This is a specific RFID-based standard that typically operates at a frequency of 13.56 MHz and enables contactless data transmission over distances of up to approximately ten centimeters.

[0043] "Housing" refers to the part of the pressure measurement unit that contains a gas-filled cavity, a printed circuit board, and a pressure sensor. Additional components may be located within the cavity or within the walls of the housing. The walls of the housing include at least a flexible dome and optionally other components such as a base.

[0044] "Gas-tight" means that when subjected to a pressure force of up to 80 mmHg, preferably 150 mmHg, and ideally 200 mmHg, no significant amounts of gas escape from the housing's cavity. However, minimal gas leakage—e.g., in the range of a few nanomoles—can occur and is irrelevant to measurement accuracy. "Embedded" means that a component is partially or completely embedded in a carrier substance. Embedding is a permanent and irreversible bond that ensures the greatest possible protection for the embedded component and has a positive impact on its service life and storage stability.

[0045] The term "cable" refers to an electrical conductor. It can be an insulated electrical conductor with an insulating outer sheath.

[0046] The terms “cavity,” “interior,” and “housing interior” mean the same thing and are interchangeable.

[0047] The term “distal” refers to a spatial arrangement in which the corresponding element is aligned away from the skin during use of the mobile pressure measuring unit and thus points away from the skin.

[0048] The term “proximal” refers to a spatial arrangement in which the corresponding element is aligned towards the skin during use of the mobile pressure measuring unit and thus points towards the skin.

[0049] Where reference is made to anatomical or morphological terms, this primarily refers to the corresponding parts of the human body (e.g. limbs).

[0050] The Shore values ​​used here refer to the Shore A scale measured according to ISO 7619-1.

[0051] The flexible dome can, for example, be shaped like a hemisphere. Variations of the hemisphere shape are possible (e.g., an arched shape). The flexible dome can also be designed as a geometric dome, in which case it has corners. The dome has a three-dimensional shape. If the dome stands on a base, the center of the dome should be its highest point (measured from the base).

[0052] The flexible dome is made of a material suitable for application to the user's skin, i.e., a skin-compatible material. Alternatively, the dome can be made of two or more such materials, which can be present as a mixture or as distinct, interconnected layers. Skin-compatible means that no toxic, sharp-edged, or particularly rough materials may be used. Likewise, the material must not react with or stain the skin. Furthermore, the material must not change its properties when exposed to body heat. In addition, the dome material must be gas-tight and must not undergo plastic deformation under pressure forces of up to approximately 80 mmHg. At the same time, the dome's flexibility should allow for reversible deformation under pressure. Because the dome is flexible, it adapts to the contours of the body.At the same time, the dome shape ensures good pressure distribution, preventing the pressure measurement unit from being pressed into the wearer's skin. This is especially important because the mobile pressure measurement unit is pressed toward the body tissue by the compression textile during use.

[0053] Synthetic materials that meet the above requirements are recommended as they are resistant to chemical influences and can be easily cleaned. Certain plastics are suitable, including soft PVC, silicones (polyorganosilicates), elastomers and polyurethanes (PU). This is preferably a silicone or a thermoplastic elastomer. The flexible dome particularly preferably contains or is made of polyurethane. Thermoplastic polyurethane (TPU) is most preferably used. Rubber materials can also be used as long as they are sufficiently tough. Rubber-based materials are technically suitable, although materials that can cause contact allergies (e.g. latex) are not recommended. Non-allergenic rubber-based materials such as neoprene are recommended. Another suitable material of natural origin is leather.Combinations of different materials are possible. For example, the leather can be combined with a layer of butyl rubber on the inside. In this case, the rubber compound does not come into contact with the skin and cannot cause an allergic reaction.

[0054] The first and second pressure sensors can be identical or different. For example, the first pressure sensor for measuring the outside air pressure can be splash-proof or water-resistant, while the second pressure sensor inside the housing can be without water protection. Together with the circuit board, the pressure sensors serve to determine the pressure difference between the inside of the housing and the outside air pressure. It is recommended to use two sensors with the same or comparable measurement accuracy to avoid discrepancies in determining the pressure difference. The pressure sensors can be designed as barometric pressure sensors. They can be capacitive or resistive sensors.The first and / or second pressure sensor can be one of the following types: piezoresistive pressure sensor, frequency analog pressure sensor, capacitive pressure sensor, pressure sensor with Hall element, inductive pressure sensor, silicon pressure sensor, or strain gauge pressure sensor. The pressure sensors can have one or two charge amplifiers or be coupled with them. When using piezoresistive pressure sensors, the use of at least one charge amplifier is recommended. If both pressure sensors are piezoresistive, two charge amplifiers (one charge amplifier per sensor) can be installed. Piezoresistive pressure sensors typically contain a piezoresistive pressure sensor element. Such an element can contain or be made of silicon. When using pressure sensors with a Hall element and digital output, bipolar or unipolar pressure sensors with a Hall element can be used.Optionally, the first and / or second pressure sensor can optionally have a pressure transducer.

[0055] The first pressure sensor communicates with the atmospheric air. This means that it is positioned such that it can measure the ambient air pressure. For this purpose, the first pressure sensor can also be located partially outside the housing or embedded in the housing wall. The first pressure sensor can therefore be located at least partially inside the housing. In this way, the first pressure sensor is protected from mechanical forces, including forces emanating from the contact pressure to be measured. In particular, it can be provided that the first pressure sensor does not protrude from the housing or is flush with the housing, or that the outer surface of the housing (in particular the base) projects beyond the first pressure sensor, so that the first pressure sensor does not damage the bandage when measuring the contact pressure and does not leave marks on the skin.

[0056] The second pressure sensor is located inside the housing. Preferably, it is plugged onto the circuit board and thus fixed within the housing. Alternatively, the second pressure sensor can be attached to one of the interior walls of the housing, and the connection to the circuit board can be established via a cable. Preferably, the mobile pressure measuring unit additionally contains a spacer for the second pressure sensor. The spacer has a height that exceeds the height of the second pressure sensor, so that when mounted, the spacer projects beyond the second pressure sensor and thus prevents the dome from resting on the second pressure sensor as a result of the contact pressure, which would impair the gas flow into the housing of the second pressure sensor and distort the measured values.Furthermore, the second pressure sensor is protected from mechanical forces that could be transmitted from the dome to the second pressure sensor during use of the pressure measuring unit. The spacer is designed as a body or an arrangement of bodies that partially or completely surrounds the second pressure sensor, wherein the spacer is fastened in the interior of the mobile pressure measuring unit. The spacer is preferably fastened to the base or the circuit board. The spacer can consist of one part or an arrangement of several parts. For example, the spacer can be provided by one or more injection-molded parts. At the same time or independently, the spacer can be horseshoe-shaped, perforated, and / or partially enclose the second pressure sensor.A continuous annular design of constant height is not recommended for the spacer, as it could be covered by the dome during use, thereby restricting gas exchange with the rest of the interior of the mobile pressure measurement unit. This annular design of constant height can therefore be excluded from the invention.

[0057] In this sense, the invention comprises a mobile pressure measuring unit wherein the second pressure sensor is located within a horseshoe-shaped, perforated or partially enclosing spacer and wherein the spacer is fastened to the printed circuit board or the base in the housing interior and has a height which projects beyond the second pressure sensor in the direction of the dome, so that the second pressure sensor is protected from direct contact with the dome as soon as the dome is elastically deformed (pressed in) under the action of a compressive force - such as the contact pressure to be measured - and consequently approaches the second pressure sensor.

[0058] Exemplary spacers can be seen in Figs. 12a and 12b and the arrangement of a spacer on the circuit board in relation to the second pressure sensor is shown in Fig. 13.

[0059] The spacer preferably protrudes 3 mm, preferably 2 mm, and ideally 1 mm above the second pressure sensor when mounted. These values ​​can be adjusted using a length measurement, for example, orthogonally from the circuit board. A smaller height difference has the advantage that the dome can deform further under the contact pressure before it hits the spacer, resulting in a higher measurable maximum pressure.

[0060] Pressure sensors that operate with low current and low voltage are recommended. A low current can be, for example, 1–10 pA during measurement. A low voltage can be, for example, 1–4 V during measurement, preferably 1.2–3.6 V. For sensors that generate data at regular intervals when powered, the latter values ​​refer to a measurement rate of one measurement per second (1 Hz). The pressure sensors can be equipped with temperature compensation, which prevents distortion of the measured values ​​due to temperature fluctuations. The temperature compensation can be provided by a temperature sensor. Furthermore, the temperature compensation can have a decoupling unit or be present as such.In the decoupling unit, the reactive unit of the sensor - in the case of piezoelectric sensors, the piezo element - is built on a separate bearing, which largely prevents disturbances such as material stresses caused by temperature fluctuations. Pressure sensors with a digital interface are preferred, as this eliminates the need for an additional analog-to-digital converter. Instead, the digital-to-analog conversion takes place within the pressure sensor within an evaluation circuit, also known as an application-specific integrated circuit (ASIC). The reactive unit can be located within a micro-electro-mechanical system (MEMS). The MEMS can be connected to the ASIC via bond wires. The reactive unit, the ASIC, and the bond wires can be housed in a casing and / or on a base. For pressure sensors with a digital interface, the use of a semiconductor casing orA semiconductor socket is recommended. The entire shell does not have to be made of semiconductor material. For digital interfaces, the socket can be designed as a Land Grid Array (LGA), Pin Grid Array (PGA), or Ball Grid Array (BGA). The socket contacts can be spring-loaded to minimize mechanical interference.

[0061] In principle, all sensor types described here can be equipped with a digital interface. Alternatively, a linear interface can also be used. According to a particularly preferred embodiment of the invention, the first and / or second pressure sensor is a digital, calibrated, linearized, and temperature-compensated pressure sensor.

[0062] The pressure sensors can have a buffer memory that can temporarily store measured values. The buffer memory can, for example, be designed so that 3 - 40 measured values ​​can be saved before they are output via the interface. The buffer memory has the advantage that measured values ​​that are generated faster than they are read out are not immediately lost. The circuit board can be a printed circuit board (PCB) or printed circuit board assembly (PCBA). The circuit board is preferably flexible so that it can adapt to external forces without breaking. For this purpose, the circuit board can contain or be made of polyimide. The circuit board is preferably made of polyimide with copper coating on both sides, which guarantees particularly pronounced flexibility while also ensuring high mechanical resilience.The first and / or the second pressure sensor can each be independently plugged directly onto the circuit board, integrated or embedded into the circuit board, or connected to it by cables. Preferably, at least the first of the two pressure sensors is integrated or embedded into the circuit board. The circuit board further comprises an RFID transponder or is connected to one. The circuit board can be connected to an RFID transponder directly or indirectly. In this case, "direct" means that the RFID transponder is plugged onto the circuit board or is integrated or embedded into the circuit board (the circuit board contains the RFID transponder including antenna and RFID chip). "Indirect" means that the RFID transponder is connected to the circuit board by means of one or more cables.Accordingly, the mobile pressure measuring unit according to the present invention may comprise an RFID transponder in the housing, which is preferably connected directly or indirectly to the circuit board.

[0063] The RFID transponder contains an antenna and an RFID chip. The transponder can be a read-and-write transponder. The associated memory size can be, for example, 32 bytes to 512 kbytes. The memory size is preferably 2 kbytes, 4 kbytes, 8 kbytes, 16 kbytes, 32 kbytes, 64 kbytes, or 128 kbytes. Part of the memory can also be designed as read-only memory to prevent unwanted overwriting of data. Furthermore, it is possible to install an additional, separate read-only memory of the size specified above. If read-only memory is used, it should be designed as permanent memory. The RFID chip can be an NFC chip. The chip can be a microcontroller or be part of one. It can also contain other components. The antenna usually contains a coil and a capacitor or is connected to these units.Furthermore, the antenna must be RFID-capable and thus capable of operating at the frequency of the electromagnetic field emitted by the RFID reader. Common frequencies are 125 kHz, 13.56 MHz (NFC), 868 MHz, and 2.45 GHz. The antenna is preferably a loop antenna. This allows a large portion of the housing's interior space, or in versions with a base, a large portion of the base's footprint, to be used to convert the electromagnetic field emitted by the reader. This results in a more stable wireless connection and increases its range. Since it can sometimes be difficult for the user to determine the exact position of the mobile pressure measurement unit beneath the compression textile, a high-performance antenna leads to improved user comfort.

[0064] In exceptional cases, the RFID chip can be part of the circuit board. In this case, it is sufficient to connect an antenna to the circuit board to maintain the interconnectedness of the two components, circuit board and RFID transponder.

[0065] Furthermore, the circuit board can include a microcontroller operatively connected to the two pressure sensors. According to a preferred embodiment, both the first and second pressure sensors each contain a microcontroller, so that each of the two pressure sensors outputs a digital signal and no additional microcontroller is necessary on the circuit board.

[0066] To determine the contact pressure, the measured value of the outside air pressure generated by the first pressure sensor must be subtracted from the measured value of the gas pressure inside the housing generated by the second pressure sensor. This calculation can take place either in the mobile pressure measuring unit or in the RFID reader. Preferably, the calculation takes place in the RFID reader. In this way, components on the circuit board can be saved and power consumption can be reduced. During the development of the invention, it was discovered that in most cases the dome does not deform proportionally to the contact pressure (depending on the material used and the spatial design). This is possibly due to the fact that part of the compressive force is absorbed during the deformation of the dome and is therefore not passed on to the second pressure sensor in the interior.The problem appears to have been unknown in the state of the art or its impact on measurement accuracy was underestimated. In cases where this problem occurs, it is sensible to create a calibration curve and incorporate this into the calculation of the measured value mentioned above. In this way, an initially relative measured value can be converted into an absolute measured value (absolute contact pressure). It is advantageous here if the same amount of gas is enclosed in the interior of several mobile pressure measuring units (with identical characteristics) in order to be able to apply the same calibration curve to a large number of pressure measuring units. The creation of a calibration curve can be achieved, for example, by applying several different known contact pressures to the mobile pressure measuring unit (e.g.by applying determined weights) and measuring the forces registered by the pressure sensors (in particular by the second pressure sensor).

[0067] The printed circuit board is firmly connected to the housing. The connection should preferably be non-electrically conductive, i.e., it should act as an insulator. However, since the housing itself is an insulator in most embodiments (depending on the material used), this is not always required. The printed circuit board can be connected to the housing, for example, using plug-in connectors, synthetic resin, adhesive, or adhesive tape. The adhesive tape is preferably double-sided adhesive. If the printed circuit board is compact—for example, if its longitudinal axis has a maximum length of 6 cm—attaching it with double-sided adhesive tape is the preferred method. Since the adhesive tape is located inside the housing, the adhesive in the adhesive tape does not necessarily have to be biocompatible.This type of fastening allows the circuit board to be integrated into the housing or fixed to the inside of the housing quickly, cost-effectively and with little effort. The adhesive tape preferably has the same dimensions (when viewed from above) as the circuit board. This has the advantage that the adhesive tape can be positioned flush in a frame that also has the same dimensions as the circuit board. Furthermore, the adhesive tape preferably has a recess or hole that overlaps with the opening for the first pressure sensor when the adhesive tape is applied to the base and encloses it in a gas-tight manner. In this way, the first pressure sensor can be guided through the hole in the adhesive tape and positioned in the opening. This prevents gas from escaping from the housing via the opening and at the same time the first pressure sensor communicates with the atmospheric air.Particularly preferably, the adhesive tape fulfills both of the last-mentioned features (dimensions such as circuit board and hole for first pressure sensor).

[0068] Any active RFID-enabled device that has or is connected to an electrical energy source and is capable of generating an electromagnetic field that can be used by the antenna of the mobile pressure measuring unit to generate an electric current can serve as a reader. In addition, the reader must be capable of receiving the measured values ​​generated by the mobile pressure measuring unit, which the pressure measuring unit transmits contactlessly by manipulating the electromagnetic field. Optionally, the reader can have an optical display to output the read values. Alternatively, the reader can have a permanent, writable memory so that the read values ​​can be transmitted to another device and output there. The RFID-enabled reader can be an NFC-enabled reader. Examples of frequently used NFC-enabled readers include smartphones.The operating systems Android (from version 4) and iOS (from version 13) support NFC communication, provided the associated smartphone has the appropriate hardware.

[0069] The reader should be equipped with the necessary software to initiate the reading process and display the transmitted measured values. In the case of a smartphone, such an application can be designed as an app. This makes it possible to create suitable applications in the programming languages ​​Kotlin (for Android) or Swift (iOS).

[0070] Preferably, the housing of the mobile pressure measuring unit includes a base in addition to the flexible dome. The base is opposite the flexible dome and has an inner side facing the dome and an outer side facing away from the dome. The base is connected to the dome in a gas-tight manner, such that the gas-filled cavity is formed between the base and the flexible area. A gas-tight connection can be created, for example, by welding, gluing, using synthetic resin, vulcanizing, or using gas-tight adhesive tape. Thus, the invention includes a form of mobile pressure measuring unit in which the flexible dome and the base are welded, glued, or vulcanized to one another in a gas-tight manner. Preferably, the flexible dome and base are welded to one another. Particularly preferably, they are ultrasonically welded.Ultrasonic welding is preferred because it avoids thickening and sharp edges in the weld area and significantly improves the feel during subsequent application. If necessary, all electronic components (circuit board, transponder, pressure sensors) can be attached to the base.

[0071] Vulcanization creates a rubber or elastomer bond between the dome and the base.

[0072] Furthermore, the dome and base can be glued together. Examples of suitable adhesives are chemically curing adhesives, such as epoxy resin adhesives or polyurethane adhesives.

[0073] A bond between the dome and base using suitable plastics is also possible. In addition to the elastomers mentioned above, suitable plastics include most thermoplastics such as ABS (acrylonitrile butadiene styrene copolymers) or PLA (polylactide). In the case of PLA, an admixture of at least one amorphous polymer such as polyvinyl chloride, polystyrene, polycarbonate, or polymethyl methacrylate is recommended.

[0074] The base offers the advantage that components that are installed inside the case can be attached to the inside of the base. This includes, in particular, the printed circuit board. This simplifies the manufacturing process and protects the installed components.

[0075] The base of the mobile pressure measuring unit is preferably elastic. More preferably, it is rubber-elastic. It is recommended that the base be designed so that it has a Shore A value of 20 to 80. The base preferably has a Shore A value of 25 to 75, more preferably 30 to 70, and most preferably 40 to 60. Ideally, the mobile pressure measuring unit contains a base that is rubber-elastic and at the same time has a Shore A value within one of the specified ranges. Such a base conforms to the skin when pressed during compression and does not cause any unpleasant sensations in the user, such as those that arise when using sharp-edged materials. Thus, such a base is advantageous for long-term pressure measurement during compression and simultaneously increases therapy compliance. At the same time, the base can adapt to the contours of the body.

[0076] When using a rubber-elastic base, it is recommended to make it flat or essentially flat. This ensures the base remains optimally moldable to different body contours. However, if a non-elastic base is chosen, it can be manufactured slightly curved or bent (based on the cross-sectional view) for use in compression therapy on the leg. Such a shape can be adjusted to fit the leg being treated even without being elastic.

[0077] Preferably, the base is stiffer than the flexible dome. This can be achieved by selecting the materials and their layer thickness. The Shore A value of the base is particularly preferably higher than that of the flexible dome. This has the advantage that the dome deforms (reversibly) first under the influence of pressure. Components attached to the inside of the base, such as the circuit board, are thus exposed to fewer forces and are thus mechanically protected.

[0078] The base preferably contains silicone or a polyurethane such as TPU or is coated with these materials. These materials are skin-friendly, can be made gas-tight, processed quickly and precisely, and are resistant to external influences such as sweat, water, wound ointments, and disinfectants. They are also easy to clean. According to one embodiment, the silicone is a silicone rubber or a silicone elastomer. These materials have the advantage that, due to a high coefficient of friction, they prevent the mobile pressure measuring unit or the compression bandage from slipping on the pressure measuring unit. It is preferably a silicone rubber or a silicone elastomer that has a coefficient of friction > 1 on its own.A base that contains or consists of TPU also offers the advantage that TPU is particularly easy to weld, thus creating a gas-tight connection between the base and the dome in an efficient and cost-effective manner.

[0079] The base and flexible dome preferably have a smooth surface to prevent the growth of bacteria in the materials. However, it is possible to provide the surface with a three-dimensional structure to reduce the likelihood of slipping. Fibrous structures are technically possible, but are difficult to wipe clean, can become wet upon contact with moisture, be colonized by microorganisms, or become electrostatically charged, which can affect the functionality of the electronics. For this reason, the use of fibers is not recommended. According to a preferred embodiment of the invention, the mobile pressure measuring unit therefore does not contain any fibers and / or textiles such as woven fabrics or fleeces. If fibers or textiles are used, it is recommended that they be coated on the outside with silicone or polyurethane.

[0080] The housing preferably has an opening in which the first pressure sensor is attached or embedded. This opening can be located in the base. This has the advantage that the first pressure sensor hardly protrudes and the probability of it being damaged by compression textiles (e.g. medical bandages) is significantly reduced. The opening can be located in a raised area on the outside of the housing or base. In this way, the raised area forms a protective edge around the sensor. The raised area can be radial or conical, for example. However, it can also be adapted to the outline of the sensor and thus be in the form of a socket. The height of the raised area can also be adapted to the dimensions of the sensor. For example, it can have a height of 0.2 to 3 mm, better 0.3 to 2 mm, even better 0.4 to 1 mm, measured from the base area of ​​the housing or base. If the base area of ​​the housing or base isIf the base is not planar, the height is measured starting from the area of ​​the base that borders the elevation. The opening in the base is preferably round. Particularly suitable diameters for a round opening are 0.1 - 5 mm, 0.3 - 4 mm and 0.5 - 3 mm. Smaller openings have the advantage that less of the surface of the second pressure sensor is exposed. In addition, smaller openings reduce the likelihood of foreign substances such as moisture (e.g. in the form of sweat) penetrating the interior of the housing. Smaller openings can also be made gas-tight more easily, which ensures reliable and precise measurements. Furthermore, the dimensions of the opening can be designed such that the opening precisely encloses the first pressure sensor or the part of the sensor that is inserted into the opening.

[0081] It is important that the first pressure sensor is attached or embedded in the opening in the base in such a way that the housing remains gas-tight and no gas can escape from the cavity through the opening. The first sensor can be attached gas-tight in the opening by forming chemical bonds. Different substances can be used for this. For example, the first pressure sensor can be attached to the opening in the base using epoxy resin. Epoxy resin is impermeable to gas particles and ensures that the housing remains gas-tight even after the sensor is attached in the opening. Various forms of epoxy resin can also be used, including bisphenol-based epoxies, aliphatic epoxies, novolak epoxies, and halogenated epoxies.Bisphenol-based epoxy resins may be excluded from this list because, on the one hand, the harmlessness of bisphenol for the human body upon contact with skin has not been proven beyond doubt, and for this reason, the processing of bisphenol-based epoxy resins may require stricter safety precautions. One advantage of epoxy resins is that they already have a basic degree of flexibility in their initial state. This can be further increased by adding one or more plasticizers to the epoxy resin. Examples of suitable plasticizers are esters of polybasic carboxylic acids, polyhydric alcohols, rubber degradation products, and reaction products of chlorinated hydrocarbons with alkali sulfides. The plasticizers can be present in a mass fraction of 1 - 30% in the resulting plastisol, i.e. the plasticized synthetic resin. Furthermore, the gas-tight connection can also be achieved using other synthetic resins, such asPolyester resin, polyurethane resin, polyurea resin, or silicone resin, Teflon, rubber, or adhesives. Possible adhesives include—in addition to the epoxy resins already mentioned—chemically curing adhesives such as polyurethane adhesives, phenol-formaldehyde resin adhesives, cyanoacrylate adhesives, and methyl methacrylate adhesives. Polyurethane adhesives are the preferred adhesives because they exhibit high flexibility after curing and are highly resistant to bending, such as that which can occur when attaching the housing of the mobile pressure measurement unit to the human body.

[0082] Depending on the design, the opening for the first pressure sensor can also be combined with a holder for the first pressure sensor. This is particularly the case if the opening is not located in the base of the housing. The holder and the opening can merge into one another. Furthermore, the opening can also be integrated into the holder and form part of the holder. The holder can be made of a plastic such as TPE.

[0083] When electronic components are attached to the inside of the housing or base using epoxy resin, it is possible to strengthen this attachment by providing the inside with one or more notches. These notches are located at the attachment position and are arranged around the component to be attached. The epoxy resin completely or partially encloses or overlies the component to be attached and fills said notches. In this way, the contact area is increased and the attachment is strengthened. Accordingly, the mobile pressure measuring unit according to the invention can comprise one to twelve notches on the inside of the housing, for example on the inside of the base. If only one notch is to be provided, it can be arranged in a ring around the component to be attached.Each notch may have a depth of 0.1 - 8 mm, preferably 0.3 - 5 mm, particularly preferably 0.5 - 3 mm, measured from the immediately adjacent edge of the housing interior.

[0084] In addition, the first pressure sensor can be fastened in the opening by means of an adhesive strip, preferably a double-sided adhesive strip, an adhesive tape, preferably a double-sided adhesive tape, or a transfer tape. For example, a part of the sensor that protrudes beyond the opening on the inside of the housing or base can be fastened with the adhesive strip, the adhesive tape, or the transfer tape. The adhesive strip, the adhesive tape, or the transfer tape do not have to have a continuously closed surface, but can have a recess the size of the opening, creating an adhesive surface surrounding the opening on the inside of the housing or base. In addition, the adhesive strip or the adhesive tape can also overlie the pressure sensor for fixation.Preferably, in the fully assembled mobile pressure measuring unit, the opening for the first pressure sensor is enclosed by one of the latter adhesives, so that the adhesive extends laterally to the opening and the circuit board (including the first pressure sensor) is located above the opening. In this way, the opening is sealed gas-tight, and the gas quantity inside the housing remains constant even under the influence of external pressure.

[0085] Alternatively, the first pressure sensor can be plugged onto the circuit board, and the circuit board can be attached to the inside of the housing, preferably to the inside of the base, using adhesive strips, adhesive tape, or transfer tape. If the strips or tape are attached to the underside of the circuit board, they should be double-sided adhesive. If they are attached to the top side so that they overlie the circuit board, they can also be single-sided adhesive. The first pressure sensor plugged onto the circuit board is inserted into an opening in the housing, preferably an opening in the base, so that it communicates with the atmospheric air. The side of the sensor that is in the opening is usually opposite the interface side that is connected to the circuit board. The dimensions of the opening should essentially be such that the opening snugly encloses the sensor.Surprisingly, it has been shown that this method allows the first pressure sensor to be mounted in a gas-tight manner. The advantage is that this type of gas-tight mounting reduces labor and eliminates the need for additional materials (such as epoxy resin or screws). Furthermore, by eliminating screws, the structural integrity of the housing is preserved and predetermined breaking points are avoided. According to a preferred variant of this mounting, at least 90%, particularly preferably 95%, of the underside of the circuit board is fixed to the base using a double-sided adhesive strip or tape.

[0086] Particularly preferably, the two pressure sensors are each electrically connected to opposite sides of the circuit board. In this configuration, it is recommended to attach the circuit board to the base with the side connected to the first pressure sensor facing forward.

[0087] Different adhesive strips (e.g. with a paper or fabric backing) and different adhesive tapes (e.g. with a film backing made of PP, PET or PVC) that are treated with different adhesive substances (e.g. acrylic adhesive) can be used for attachment. It is important that the fastening materials are not electrically conductive. If the circuit board is to be attached via its underside and this underside is rough or uneven, the use of transfer tape can be advantageous over other fastening materials because it can compensate for unevenness better than adhesive strips or adhesive tapes. Because the transfer tape does not contain any carrier material, it is also extremely flexible. If the circuit board is attached with its underside to the inside of the housing, preferably to the inside of the base, as described above, it can be further stabilized with a frame.The frame comprises one or more elevations located on said inner side. The frame can be continuous or, in the case of multiple elevations, discontinuous. In this sense, the invention comprises a mobile pressure measuring unit in which the printed circuit board is located in a frame or is enclosed by such a frame. The frame is preferably made of the same material as the housing or the base. The frame can form a composite with the housing or the base, for example by forming the housing or base including the frame in an injection molding process. Alternatively, the frame can be adhesively bonded to said inner side or be designed as a recess in said inner side. It is important that the frame has contact with the lateral surfaces of the printed circuit board at least in two opposite positions in order to prevent the printed circuit board from slipping when subjected to external force.The height of the frame can be based on the height of the printed circuit board. Preferably, the frame has a maximum height of the printed circuit board. The frame can, for example, have a height of 0.1 - 5 mm, preferably 0.3 - 3 mm, and particularly preferably 0.5 - 2 mm. The thickness of the frame can, for example, be 0.2 - 10 mm, preferably 0.4 - 8 mm, particularly preferably 0.5 - 5 mm. Preferably, the frame is a continuous frame that encloses the entire lateral surface of the printed circuit board. Particularly preferably, the frame also encloses the first pressure sensor, and particularly preferably also the opening into which the sensor is embedded, wherein direct contact between the frame and the opening is not necessary when the sensor is plugged onto the printed circuit board, since the board is already stabilized by the frame.

[0088] Furthermore, there can be vertical and / or horizontal struts on the inside of the base. The struts represent static reinforcements of the base. In this respect, they can also be referred to as reinforcing struts. They can rest on the bottom (inside) of the base or be placed on the bottom of the base. If the base contains both vertical and horizontal struts, these can be arranged at right angles to one another and then form a lattice-like waffle structure (network structure) when viewed from above. If the base has a frame for the circuit board, the struts can reach all the way to the frame and optionally merge into the frame. In this case, the struts form a connection with the frame and the base. The struts have the advantage that the base is more torsionally rigid and that the flexible dome gives way as a result of external forces (e.g. contact pressure during compression therapy).The electronic components located in the base area are protected against deformation and breakage. The struts can have the same height and thickness as the frame. The spacing between the struts can be 2-10 mm, preferably 4-8 mm, and particularly preferably 5-7 mm.

[0089] The circuit board is preferably flexible in order to adapt to body contours and to avoid damage due to external forces (e.g. due to the contact pressure generated during compression therapy). Particularly preferably, the housing and circuit board of the mobile pressure measuring unit are both flexible. Very particularly preferably, the housing and circuit board of the mobile pressure measuring unit have an E-module of maximum 2 Gpa, better 0.05 to 1.8 Gpa, even better 0.1 to 1.3 Gpa and most preferably 0.2 to 1 Gpa. According to a further embodiment, the housing has a higher E-module than the circuit board. In this way, the majority of the external forces are absorbed by the insensitive housing and only a fraction of these forces are passed on to the sensitive circuit board.

[0090] Preferably, the circuit board is flexible and has a Shore A value that is less than or equal to the Shore A value of the housing or base. This largely absorbs external forces acting on the mobile pressure measuring unit. For example, the circuit board can have a Shore A value of 19-79, preferably 24-74, particularly preferably 29-69, and most particularly preferably 39-59.

[0091] The flexibility and / or the above-mentioned Shore A values ​​of the printed circuit board can be achieved by using a printed circuit board containing polyimides. The polyimides should be present as a flexible polymer. Flexibility can be optimized by making the majority of the printed circuit board polyimides. Preferably, the printed circuit board consists of at least 90% polyimides, or the electrically non-conductive (electrically insulating) portion of the printed circuit board consists of polyimides. Examples of usable polyimides are polysuccinimide, polybismaleimide, polyimidesulfone, polyetherimide, and polymethacrylimide. Due to their flexible properties, a printed circuit board containing polyimides is well suited to adapting to body contours within the housing and exhibits high fracture resistance when exposed to external forces.

[0092] Preferably, the mobile pressure measuring unit according to the present invention does not comprise any cables located outside the housing. Instead, the entire electronics are generally located inside the housing. Only the first pressure sensor requires contact with the outside, as it measures the outside air pressure. Preferably, at least 90%, preferably 95%, particularly preferably 99% of the volume of the first pressure sensor is located inside the housing. Most particularly preferably, the entire first pressure sensor is located inside the housing and is only in contact with the outside air pressure via an opening in the housing. The advantage of this embodiment lies in the particularly good protection of the electronics. Since cables on the skin can also be perceived as annoying by the user, wearing comfort is also increased.

[0093] The mobile pressure measuring unit according to the invention makes it possible to dispense with a position sensor (e.g., gyrometer, magnetometer). Pressure measurement is performed without a position sensor. Accordingly, the invention includes a mobile pressure measuring unit that does not contain a position sensor. The contact pressure is measured regardless of the user's body position. The advantage is lower energy consumption and a more compact design. In order to be able to compare the individual measured values, e.g., to determine whether tissue decongestion has occurred during compression therapy, the user can assume the same body position during each measurement (e.g., always lying down or always sitting).

[0094] The pressure measuring unit preferably does not contain a storage device for electrical energy. Such a storage device refers to components that chemically store electrical energy (e.g. batteries or accumulators). Other types of storage devices for electrical energy (e.g. capacitors), however, can be part of the mobile pressure measuring unit. The associated advantage is that the pressure measuring unit is not dependent on an internal power supply that could become exhausted. Since compression bandages are usually applied by medical professionals, it is unreasonable for the user or patient to remove the bandage in order to ensure the power supply. The mobile pressure measuring unit according to the present invention is supplied with energy in particular from the outside via the electromagnetic field of the reader.The supply of electrical energy to the reading device can be ensured without having to remove the textiles used for compression. Accordingly, according to this preferred embodiment, the invention includes a mobile pressure measuring unit that does not contain a storage device for electrical energy. The mobile pressure measuring unit preferably draws the electrical energy required to perform a measurement from an electromagnetic field. The electrical energy can be provided using an antenna that is part of the transponder. This provision occurs through interaction of the antenna with the electromagnetic field. The electromagnetic field can be generated by an RFID-enabled reading device such as a smartphone. The required electrical energy is preferably provided exclusively using said antenna.In this sense, the invention comprises a mobile pressure measuring unit which can obtain the electrical energy required to carry out a measurement from an electromagnetic field using an antenna, and wherein the antenna is part of the passive RFID transponder.

[0095] The antenna can have various shapes. Preferably, the antenna is at least partially curved, at least partially round, or has one or more turns. Multiple turns means at least two, but preferably at least three turns. This increases the energy yield and the maximum distance between the source of the electromagnetic field (e.g., smartphone) and the mobile pressure measuring unit. Furthermore, the interior space of round mobile pressure measuring units can be optimally utilized. At the same time or independently, the antenna can be integrated or embedded in the circuit board, thereby providing optimal protection. One turn can be a complete circumnavigation of the circuit board by the antenna conductor in plan view.

[0096] The RFID-compatible transponder of the mobile pressure measuring unit is preferably a passive NFC-compatible transponder. The frequency used is 13.56 MHz. The advantage of such an NFC-based approach is that most modern smartphones have NFC and can function as a reader within the scope of this invention. Furthermore, NFC not only makes it possible to read the measured value of the contact pressure using the reader, but also to send data to the mobile pressure measuring unit and store it there in an optionally available memory. For this purpose, the mobile pressure measuring unit according to the invention can have a writable internal memory (read-write memory), which is, for example, a component of the circuit board or the transponder. The memory can, for example, have a capacity of at least 128 kb. The following can be stored in the memory, for example: the number of measurements, the date and time of the measurement, and the pressure value.The advantage is that medical personnel can use the stored values ​​to determine whether the tissue has decongested. If decongestion has occurred, for example, the type of compression bandage can be changed or a compression bandage can be replaced with a compression stocking. The mobile pressure measuring unit according to the invention can comprise an adhesive layer on the outside. The adhesive layer can be located on the outside of the flexible dome and / or the base and can be covered by a removable cover film. The cover film can have a pull-off tab. The adhesive layer can be used to fix the mobile pressure measuring unit to the skin or to position it until the pressure measuring unit is covered by the compression textile and thus fixed.

[0097] The adhesive layer is preferably designed as a double-sided adhesive film.

[0098] An adhesive layer located on the outside of the base should be a skin-compatible adhesive layer. A preferred skin-compatible adhesive layer is an adhesive layer that includes or is made of silicone adhesive or acrylic adhesive. An adhesive layer located on the outside of the dome or base can also be used to adhere the mobile pressure measuring unit to the compression textile. For example, the mobile pressure measuring unit can first be positioned or adhered to the skin with the dome first. It is then wrapped with a compression bandage that adheres to an adhesive layer on the base. The adhesive layer is preferably located on the side of the mobile pressure measuring unit where the opening for the first pressure sensor is located, i.e. the side that faces away from the skin during use.The advantage here is that the mobile pressure measurement unit is secured to the compression textile via an adhesive layer, but the skin beneath the pressure measurement unit can still move. For example, the skin can stretch or contract as the user moves without the mobile pressure measurement unit slipping. In summary, if the mobile pressure measurement unit contains the adhesive layer, it can be secured to the user's skin and / or to a compression bandage using this adhesive layer.

[0099] Preferably, the flexible dome of the mobile pressure measurement unit can consist of a single layer of uniform thickness. Minor production-related deviations may occur. Thus, the flexible dome can consist of a single layer of essentially uniform thickness. The single layer can be a polymer such as a thermoplastic. However, it can also be a mixture of two or more substances. For example, additives can be present. The advantage of avoiding multiple layers is that delamination under load is eliminated. A uniform thickness prevents material weak points.

[0100] Preferably, the flexible dome—particularly when consisting of a single layer of substantially uniform thickness—has a layer thickness of 0.2–3 mm, more preferably 0.3–2 mm, and most preferably 0.4–1 mm. Using a thin layer results in more accurate measurements, as thin layers absorb less external pressure forces through elastic material deformation and instead better transmit them to the gas-filled cavity, where the pressure change can be detected by the second pressure sensor. Furthermore, the use of thick layers in the flexible dome can lead to an undesirably increased output pressure inside the housing due to the weight of the flexible dome.

[0101] The flexible dome preferably contains or is made of polyurethane. The polyurethane can be TPU. If the mobile pressure measurement unit has a base, both the base and the flexible dome can be made of TPU. The advantage of this is that the base and flexible dome can be permanently joined together by welding in a gas-tight manner, and this welding step can be easily automated. Ultrasonic welding is recommended, especially when using components made of thermoplastic materials such as TPU.

[0102] The mobile pressure measuring unit preferably has at least one plane of symmetry. For example, it can be trapezoidal in plan view. There can also be at least two planes of symmetry. For example, the mobile pressure measuring unit can be rectangular in plan view. There can also be at least three planes of symmetry. For example, the mobile pressure measuring unit can be square in plan view. The corners of the geometric shapes mentioned here can be rounded, as edges lead to an unpleasant feeling on the skin. The mobile pressure measuring unit is preferably elliptical or circular (radial) in plan view. In this way, corners are avoided from the outset and the contact pressure displaces the flexible dome evenly in all directions, which prevents possible material weak points.

[0103] The transponder preferably comprises a loop antenna or an RFID or NFC loop antenna that encloses at least 15% of the base area of ​​the mobile pressure measuring unit. If the pressure measuring unit has a base, the base area is determined by the underside of the base. Larger loop antennas generate more power and ensure a greater range. In this sense, the loop antenna can also enclose at least 20%, better at least 30%, even better at least 40%, and ideally at least 60% of the base area of ​​the mobile pressure measuring unit. This refers to the area that can be maximally covered by the external dimensions of the loop antenna, i.e. when the frame portion of the antenna lies flat (not upright) without any existing connections, etc. For mobile pressure measuring units with a base, the above description can also refer to the base area of ​​the base.

[0104] In addition, advantageous dimensions of the loop antenna can also be specified in absolute values. In this sense, the loop antenna can have an area of ​​at least 200 mm 2 A circular loop antenna can have a diameter of at least 16 mm. A square loop antenna can have an edge length of at least 14 mm. Loop antennas that have the listed dimensions can be both RFID and NFC-capable.

[0105] The mobile pressure measuring unit is a device for measuring contact pressure. Other types of measurement may be explicitly excluded. For example, the measurement of blood pressure or the measurement of blood oxygen levels. Thus, the mobile pressure measuring unit for measuring contact pressure cannot contain a sensor suitable for measuring blood pressure, pulse, or blood oxygen levels. In these cases, the mobile pressure measuring unit is not a blood pressure monitor, a pulse rate monitor, or a pulse oximeter, and does not contain such a measuring unit.

[0106] Preferably, the mobile pressure measuring unit is splash-proof. If the housing has an opening, this opening can be sealed with a gas-permeable but water-impermeable membrane. However, this is not necessary for the pressure measuring unit to be splash-proof. Instead, a small opening can be used. A small opening can have an area of ​​up to 10 mm 2 , better up to 8 mm 2 , even better up to 5 mm 2 and preferably up to 3 mm 2 If the opening is circular, it can have a diameter of up to 4 mm, preferably up to 3 mm, even better up to 2 mm, and ideally 1 mm. The mobile pressure measuring unit is preferably protected against dust and contact to at least IP5X. In addition, the mobile pressure measuring unit can be protected against water to at least IPX1, preferably at least IPX2, even better at least IPX3, and ideally at least IPX4.

[0107] The mobile pressure measurement unit also has the advantage of being disinfectable using disinfectant. Accordingly, the mobile pressure measurement unit is disinfectable.

[0108] For example, using commercially available alcohol-based disinfectants or surface disinfectants containing glutaral, benzyl-C12-C18 alkyldimethylammonium chloride, and / or didecyldimethylammonium chloride. The advantage is that the same mobile pressure measurement unit can be used by different users or patients without the unintentional spread of germs (e.g., from open wounds). If the mobile pressure measurement unit is to be disinfected, it is recommended to use a pressure measurement unit without an adhesive layer.

[0109] The gas-filled cavity preferably contains air. However, it may also contain another gas or gas mixture, such as one or more noble gases or nitrogen. The gas in the cavity preferably has a low water vapor content. The water vapor content may be less than 6 g of water per m 3 Gas at 20°C. Preferably less than 5 g, even better less than 4 g, and ideally less than 3 g. The gas (e.g., air) is particularly preferably free or essentially free of water vapor. The drier the gas in the cavity of the pressure measuring unit, the lower the likelihood of condensation inside the housing during temperature fluctuations. This provides additional protection for the electronic components.

[0110] The mobile pressure measurement unit (without optional cover films) or the housing preferably has a height of 2–8 mm in its initial state. "Initial state" here means that no contact pressure is exerted. The mobile pressure measurement unit particularly preferably has a height of 2.5–4 mm in its initial state. This is especially true if the housing has or consists of a dome and a base. Flat (i.e., low) designs have the advantage of not being bulky under compression textiles and are not perceived as distracting by the user.

[0111] Preferably, both the first and / or second pressure sensors of the mobile pressure measuring unit are digital pressure sensors. The advantage of this is that the circuit board does not need to be connected to an additional analog-to-digital converter.

[0112] The invention further includes a set for compression therapy comprising a medical bandage and the described mobile measuring unit. The set can further include outer packaging in which the bandage and measuring unit are located. The medical bandage is a bandage that can be used for compression therapy and can also be referred to as a compression bandage. This can be a cohesive bandage. Such a cohesive bandage can be cohesive on one or both sides. Furthermore, the bandage can contain one or more materials from the following group: polyester, polypropylene, viscose, cotton, polyamide, and elastane. Preferably, the bandage contains or consists of polypropylene and elastane. The set can also contain a padded bandage, which is used to compensate for skin irregularities before compression therapy. The padded bandage can contain polyester and elastane and can also be cohesive.The medical bandage and the optional padded bandage are breathable, allowing the external air pressure to be measured beneath the bandage during compression therapy. A padded bandage can be a bandage that contains at least one nonwoven layer (e.g., made of polyester) with a surface weight of at least 60 g / m². 2 , preferably at least 70 g / m 2 , preferably at least 80 g / m 2 The padding bandage can optionally contain a further - second - nonwoven layer, with the two nonwoven layers being connected to each other (e.g. sewn).

[0113] The medical bandages usable with the mobile pressure measurement unit can, for example, have a KADI (Ankle-Bracelet Pressure Index) of 0.6 to 1.3. Optionally, visual application indicators can be provided on the surface of the medical bandages. These indicators can, for example, be designed as hexagons. The application indicators provide visual feedback during application as to whether the bandage is being stretched correctly. For example, when stretched correctly, an irregular hexagon can deform into a hexagon with equal sides. The exact contact pressure can then be recorded using the mobile pressure measurement unit. Such bandages with application indicators can also be included in the described set.

[0114] Preferably, the mobile pressure measuring unit is integrated into a textile material. The textile material can be a bandage. The mobile pressure measuring unit can be completely (on all sides) surrounded by the bandage. This can be achieved, for example, by sewing the pressure measuring unit into the bandage. To achieve this, it is possible to first place the pressure measuring unit on the bandage, then fold it in (fold any excess textile material over the pressure measuring unit) and then fix this arrangement by sewing. The integration of the pressure measuring unit into a bandage has proven to be very advantageous. This prevents a build-up of heat or moisture between the mobile pressure measuring unit and the wearer's skin, which could otherwise occur with direct placement. Even more important is the fact that the textile material of the bandage (e.g.Cotton) has the elastic properties of skin (stretching and contraction), making movements of the corresponding limbs more comfortable for the patient, which promotes healing progress and therapy compliance. Furthermore, marks on the (often already irritated) skin are avoided. In this sense, the invention encompasses a bandage containing the mobile pressure measurement unit. The bandage, into which the pressure measurement unit is integrated, can simultaneously serve as the therapeutic bandage (compression bandage) or be present as an additional bandage that lies beneath the actual compression bandage or beneath a padding bandage and a compression bandage during use.

[0115] The textile material into which the mobile pressure measurement unit is integrated (e.g., a bandage) can contain polyester and / or elastane. The elastane can comprise PU. Furthermore, the textile material can comprise at least one nonwoven fabric. Preferably, the textile material comprises two interconnected layers of nonwoven fabric. The two nonwoven fabrics can be sewn together using an elastane-containing thread. The nonwoven fabric(s) can contain polyester and / or have a basis weight in the range of 20–80 g / m². 2 Preferably, the fleece located above the dome has a basis weight of 50 - 70 g / m 2 to achieve a particularly skin-friendly effect.

[0116] Particularly when the mobile pressure measurement unit is integrated into the bandage, it can be advantageous to have a visual (optical) mark on the bandage that points away from the patient's skin during use (distal alignment). This ensures that the mobile pressure measurement unit is spatially correctly aligned to the skin. This visual mark can be created, for example, by inserting a thread that visually stands out from the background of the bandage. At the same time or independently, a visual mark can indicate up to which point the bandage should be wrapped around the extremity to be treated, enabling the user to cut off the area that protrudes beyond the visual mark.

[0117] In this sense, the invention also encompasses a textile material, which is preferably a bandage or compression bandage, containing the mobile pressure measuring unit, wherein the textile material optionally has the visual marking or markings described above.

[0118] The set can also contain a QR code. The QR code can be printed or affixed to the mobile pressure measuring unit, the medical bandage or the outer packaging. Furthermore, the QR code can be displayed on a printed product included in the outer packaging (e.g. an instruction manual). The QR code can encode a URL. The URL can be a download link for a measuring application or an installation file for such a measuring application. Alternatively, the URL can be used to access instructions for use in text or video format. Furthermore, the QR code can encode a sequence of numbers, e.g. five to ten, which can be an activation number. The activation number can be unique so that each mobile pressure measuring unit is assigned its own activation number via a QR code.

[0119] The invention also includes a method for producing the described mobile pressure measuring unit, in which the manufactured pressure measuring unit has a base and which comprises the following steps: a) providing the flexible dome, the base, the first and second pressure sensors, the RFID transponder and the circuit board, b) fastening the circuit board to the base, c) connecting the pressure sensors and the RFID transponder to the circuit board, wherein the first pressure sensor either has a connection to the outside of the base or is in contact with the outside of the base so that it can measure the ambient pressure d) welding the dome to the base so that a gas-tight, gas-filled cavity is formed between the dome and the base and so that the dome and base enclose the second pressure sensor, the transponder and the circuit board.

[0120] Welding during the manufacturing process can involve ultrasonic welding. Ultrasonic welding can be performed using a circular sonotrode, with a negative pressure generated within the circular sonotrode acting on the dome and / or base, causing the dome and / or base to fully adhere to the concave surface of the sonotrode.

[0121] Preferably, a predetermined amount of gas – normally air – is enclosed in the interior by welding during the manufacturing process. This predetermined amount of gas ensures better comparability of measured values ​​between several mobile pressure measuring units manufactured in the same way and also allows an optionally created calibration curve to be applied to a large number of mobile pressure measuring units in order to calibrate them. The predetermined amount of gas can, for example, be in the range of 1 cm 3 up to 100 cm 3preferably 3 cm 3 up to 20 cm 3 and especially preferred at 5 cm 3 up to 15 cm 3 These volume specifications refer to the gas volume under standard conditions (20°C, 1 atm). The specified amount of gas should be based on the volume of the housing interior. For example, without the influence of external forces, a pressure of approximately 1 atm (e.g. 0.9 atm to 1.1 atm) can prevail inside the housing at 20°C. Smaller gas volumes are preferred because they allow the construction of more compact mobile pressure measuring units that can be more easily placed under a textile material (such as a compression bandage) during compression therapy. A preferred method of enclosing a specified amount of gas inside the housing by welding is ultrasonic welding using negative pressure. This can be carried out as described above.

[0122] The base can have one or more cutouts in the edge area. The cutouts can, for example, have an area of ​​1 x 2 mm. At the same time, the flexible dome can have the same number of elevations, which are dimensioned such that they fit into the cutouts. This simplifies production because the flexible dome and the base are already pre-fixed while they are being attached to each other. After production, there is also the advantage that the connection between base and dome is more resilient because they have a larger contact area with each other. Accordingly, part of the invention is a mobile pressure measuring unit in which the base has a number of cutouts and the dome has the same number of projections (pins), and wherein the projections are precisely inserted into the cutouts.

[0123] A housing for a mobile pressure measurement unit constructed as described here is gas-tight up to an external pressure of at least 80 mmHg, preferably at least 150 mmHg, even better 200 mmHg, and ideally more than 200 mmHg. This prevents gas from escaping from the housing during compression therapy, for example.

[0124] Furthermore, a method for measuring the contact pressure during compression therapy is described here, which comprises the following steps: a) Applying the mobile pressure measuring unit to the patient's skin in the area to be treated b) Overlaying the mobile pressure measuring unit with one or more layers of a textile suitable for compression, whereby the textile can be a bandage and in this case is wrapped around the body area to be treated and the end of the bandage is optionally fixed c) Providing an electromagnetic field by a reader located near the mobile pressure measuring unit to power the mobile pressure measuring unit d) Measuring the contact pressure by the mobile pressure measuring unit e) Reading out the contact pressure measured by the mobile pressure measuring unit with the reader f) Comparing the measured contact pressure with the desired contact pressure g) Optionally correcting the contact pressure by exchangingTightening or loosening the textile Is h) Optionally repeating steps f) and g) until the measured contact pressure matches the desired contact pressure,

[0125] The textile in this procedure can be, for example, a compression stocking or a compression bandage. The desired contact pressure can also be a pressure zone. The end of the bandage can be secured with clips or adhesive strips, for example, although adhesive strips are preferred due to the lower risk of injury. Cohesive bandages can be secured to themselves.

[0126] An alternative method for measuring the contact pressure during compression therapy comprises the following steps: a I) Applying the mobile pressure measuring unit and at least one bandage to an extremity of a patient, wherein the at least one bandage is wrapped around the extremity and around the mobile pressure measuring unit in order to generate contact pressure. The mobile pressure measuring unit can be integrated into the at least one bandage, as explained elsewhere. The mobile pressure measuring unit can be fixed (held in a specific position) by the wrapped at least one bandage. a II) Optionally, further bandages (e.g. one or two further bandages) can be wrapped over the at least one bandage already applied in step a I). ​​One of the bandages can be a padded bandage. The ends of all bandages can optionally be fixed, although this fixation can optionally be omitted in the case of cohesive bandages.b) Providing an electromagnetic field by a reading device - preferably located close to the mobile pressure measuring unit - to supply power to the mobile pressure measuring unit c) Reading out the pressure value or values ​​measured by the mobile pressure measuring unit (of the first and second pressure sensors) using the reading device d) Calculating the pressure value or values ​​measured by the mobile pressure measuring unit in the reading device to obtain an absolute pressure value e) Comparing the determined absolute pressure value with the desired contact pressure f) Optionally correcting the contact pressure by replacing, tightening or loosening at least one bandage and / or the optionally present additional bandages. Step d) can comprise converting the measured value or values ​​based on a previously created calibration curve.This takes into account the fact that in most cases the dome does not deform proportionally to the contact pressure. The creation and advantages of calibration using a calibration curve have already been explained elsewhere.

[0127] Furthermore, the invention encompasses the use of the mobile pressure measuring unit for adjusting the contact pressure during compression therapy or under compression garments. Correctly adjusting the contact pressure under compression garments can accelerate muscle regeneration after physical activity. For accelerated muscle regeneration, a compression textile should be selected that generates a pressure of 10–32 mmHg, preferably 15–28 mmHg, on the extremity or on the tissue (e.g., trunk muscles). In this sense, the invention encompasses the use of the mobile pressure measuring unit to accelerate muscle regeneration or the use of adjusting a pressure on the muscle tissue that accelerates the regeneration of the muscle tissue.Furthermore, it is also possible to use the mobile pressure measurement unit to select a compression textile that exerts the aforementioned pressure on the tissue to accelerate muscle regeneration. The advantage here is that the mobile pressure measurement unit can be removed after selecting the appropriate compression textile, and the compression textile can be worn without the pressure measurement unit (e.g., overnight or during a training session).

[0128] Finally, the invention comprises a shoe, preferably a sports shoe, whose sole comprises at least one mobile pressure measuring unit. Preferably, the sole comprises at least two mobile pressure measuring units. In this way, the pressure distribution on the sole can be measured during walking or running. If the measured values ​​are to be read while walking or running, it is recommended to use an RFID frequency other than NFC, since the NFC standard is fundamentally designed to function only over short distances (approximately 10 cm). Alternatively, the measured values ​​can also be buffered and read at a later time.

[0129] Below, several concrete embodiments of the invention are presented using examples. These examples demonstrate how the invention can be implemented in practice. Using the information presented in this document, the examples can be adapted to the respective purpose, or embodiments can be generated that are independent of the examples. Examples

[0130] Example 1: Assembly and construction of a round mobile pressure measuring unit

[0131] A mobile pressure measuring unit was assembled using the components described below:

[0132] Base 1 was a body made of Desmopan® DP 6065A polyurethane from Covestro. This was a PU with a density of 1.08 g / cm 3according to ISO 1183 and a Shore A value of 66 according to ISO 7619-1. Base 1 was radial with a diameter of 55 mm, a material thickness of approximately 1 mm, and a maximum height of 2 mm. The edge area of ​​base 1 was raised by 1 mm, aligned parallel to the base surface (see Fig. 5), and had a width of 3.1 mm, giving the base a plate-shaped design.

[0133] The base had a continuous opening 7 for the first pressure sensor, extending from the outside to the inside. On the outside, the opening was surrounded by a 1 mm high mount.

[0134] In addition, the base had a grip tab 15, which the pressure measurement unit could be pulled off the skin after use. Tab 15 had a length of 10 mm and a maximum width of 8 mm. Tab 15 was oriented to extend 10 mm from the edge of the base, and its protruding end was bent when viewed from above.

[0135] The base 1 had a continuous frame 8 on its inside to accommodate the printed circuit board 6. The above-mentioned opening 7 for the first pressure sensor was also located within this frame 8. The area enclosed by the frame 8 consisted of a 26.45 mm x 22.4 mm rectangle and a 10.75 mm x 9.3 mm square, with the pressure sensor opening 7 being located in the square area.

[0136] The circuit board 6 consisted of a flexible PCBA (Printed Circuit Board Assembly) made of double-sided copper-coated polyimide with an embedded NFC antenna 20. The first pressure sensor 12 and the second pressure sensor 18 were plugged onto it, with the two sensors 12, 18 being arranged on opposite sides of the PCBA. The sensors 12, 18 were identical digital, barometric pressure sensors, each measuring approximately 2 x 2 x 0.75 mm. Both sensors 12, 18 featured a piezoresistive pressure sensor element and an ASIC (application-specific integrated circuit), with the ASIC also functioning as an analog-to-digital converter. The PCBA thus assembled was mounted in the frame using double-sided adhesive tape 2. The adhesive tape 2 had the internal dimensions of the frame 8 so that it was glued into the frame 8 with a precise fit, whereby a hole in the adhesive tape 2 allowed the first pressure sensor 12 to be passed from the circuit board into the opening 7.For this purpose, the printed circuit board 6 was mounted with the first pressure sensor 12 first, and the pressure sensor was placed in the opening 7 provided for this purpose. The opening 7 was then sealed gas-tight by the adhesive tape 2. The thickness of the adhesive tape was approximately 0.1 to 0.2 mm.

[0137] A dome 3 was then placed on the base 1 so that dome 3 and base 1 touched each other in the aforementioned edge area of ​​the base 1. The dome 3 was placed with the convex side facing outwards. The dome 3 was made of the same PU material as the base 1, was also radial and had the same diameter, but without a grip tab. The dome 3 had a layer thickness of 1 mm and a total height of 2 mm. The dome 3 was covered on its outer side with a double-sided adhesive film 4. Acrylic adhesive was used as the adhesive. The adhesive film 4 was protected by a polypropylene cover film 5. The cover film 5 had a protruding pull-off tab 14. The dome 3 and base 1 were ultrasonically welded together to form a gas-tight seal. A test showed that when a pressure of 200 mmHg was applied to the housing from the outside, no gas escaped and the housing returned to its original shape after the test.The resulting mobile pressure measuring unit had the structure shown schematically in Fig. 5. A detailed view of the dome 3 can be seen in Fig. 2, while Fig. 1 shows the circuit board 6 in detail. The fully assembled pressure measuring unit is shown in a side view in Fig. 3.

[0138] Example 2: Measuring a compression pressure

[0139] The mobile pressure measurement unit according to Example 1 was applied to a test subject's calf area at position B1. Position B1 is a frequently used area for pressure measurement in compression therapy, and its location is familiar to those experienced in compression therapy.

[0140] To apply the compression bandage, the cover film 5 was removed from the adhesive layer 2 of the dome, and the mobile pressure measurement unit was placed, adhesive layer 2 first, on clean skin. A compression bandage was applied over the calf (including the attached pressure measurement unit) and the foot (up to the metatarsophalangeal joints). Two compression bandages were wrapped around the area using a counter-directional wrapping technique. The foot was positioned at a right angle to the lower leg. The compression bandage was a "Pütter-Verband®" model from Paul Hartmann AG – a short-stretch bandage made of 100% cotton with an extensibility of approximately 90%. Each bandage was 10 cm wide and, when fully stretched, approximately 5 m long. Finally, the loose end of the last compression bandage applied was secured using a standard adhesive strip.

[0141] By reading a previously created QR code with the camera of a smartphone (Android operating system version 13), the download of a measurement app written in Kotlin was initiated onto the smartphone. After installation, the app was started, and a user account was created and activated. The target pressure interval for compression therapy was specified in the app. The test subject was placed in a sitting position. The smartphone acted as a reader and was brought to a distance of approximately 5 cm from position B1 to power the mobile pressure measurement unit and initiate the measurement. The measured value was read out via smartphone within a few seconds (also via NFC, encrypted transmission) and displayed on the smartphone display in mmHg. At the same time, the application compared the measured value with the target value interval and declared it correct.The measured value was sent using TLS encryption to the MongoDB Atlas cloud database and stored there anonymously for later retrieval. The measurement was repeated after two hours. The test subject was in the same sitting position as during the first measurement to ensure comparability of the measured values.

[0142] Example 3: Reinforced round mobile pressure measuring unit

[0143] A base 1 was provided with the same dimensions as in Example 1, but without a grip tab 15. The frame 8 on the inside was additionally surrounded by longitudinal and transverse reinforcing struts 9, which resulted in a waffle structure 17 in plan view. The reinforcing struts 9 were 1 mm high and 1 mm wide, arranged at right angles to each other and diagonally to the frame 8. The interior spaces of the rectangles of the waffle structure were up to 7 x 5 mm in size. The edge of the base was also provided with three evenly distributed recesses 10, each measuring 1 x 2 mm. A view of this base can be seen in Fig. 6.

[0144] The corresponding dome 3 had three projections in the form of pins 22 on the underside of its edge area, which were dimensioned such that they could be inserted into the recesses 10 of the base 1 and were flush with them. The pins 22 each had a height of approximately 1 mm. The remaining components and the welding step of base 1 and dome 3 were the same as in Example 1, except that the adhesive layer 4 and cover film 5 on the dome 3 were omitted.

[0145] Example 4: Moisture-resistant round mobile pressure measuring unit

[0146] A base 1 was provided with the same dimensions as in Example 1, but without a grip tab 15. The frame 8 was designed discontinuously and consisted of six separate frame elements. The opening for the first pressure sensor 7 was enclosed on the inside of the base 1 by six wedge-shaped notches 11 for filling with epoxy resin. A view of this base can be seen in Fig. 7.

[0147] The first pressure sensor 12 was inserted into the designated opening 7.

[0148] Epoxy resin was then poured into the area around the sensor 12. The fill level was chosen such that the resin accumulated both in and above the notches 11, and the notches 11 were connected by the resin. Care was taken to ensure that the resin did not reach the upper edge of the sensor 12 or its electrical contacts. The result is schematically shown in Fig. 8.

[0149] After the epoxy resin cured, a printed circuit board 6 with an embedded NFC antenna 20 was attached to the first pressure sensor 12, which was anchored in the resin. Adhesive bonding was not necessary to secure the printed circuit board. The remaining components were installed as described in Example 1. After welding base 1 and dome 3, the mobile pressure measurement unit was ready for use.

[0150] Example 5: Mobile pressure measuring unit in the shape of a rounded square

[0151] A square base 1 made of TPE was provided, which was covered on its outer side by a double-sided adhesive film 4 made of polypropylene. Silicone adhesive was used as the adhesive film. The adhesive film was covered on its outer side by a cover film 5 made of polypropylene, including a release tab 14. The base had a raised edge that formed a continuous, planar edge area.

[0152] The first pressure sensor 12 and the second pressure sensor 18 were installed on the same side of a printed circuit board 6 with an embedded NFC antenna 20, specifically on the side that would later face the inside of the dome. The prepared printed circuit board 6 was glued into the base 1 using a double-sided adhesive tape 2 made of polypropylene, so that the sensors 12, 18 faced away from the base 1. Two placement recesses pre-integrated in the base 1 helped to correctly align the printed circuit board 6. A TPE holder 16 was placed above the first pressure sensor 12 and the printed circuit board 6. For this purpose, the holder 16 had an opening 7 for the first pressure sensor 12, which encloses the sensor. The holder 16 separated the first pressure sensor 12 from the housing interior and thus acted as a gas-tight barrier between the first pressure sensor 12 and the second pressure sensor 18.In order for the first pressure sensor 12 to be in contact with the outside air pressure, the opening 7 had a tunnel located laterally, at right angles to the sensor, as air access.

[0153] The dome 3 used had a predominantly planar surface, but featured a raised portion for the mount. This raised portion also overlapped the second pressure sensor 18. The raised portion was arched above the mount 16 and tapered laterally above the second pressure sensor 18. This saved material in the dome 3. Base 1, mount 16, and dome 3 were welded together. The resulting mobile pressure measuring unit had a maximum height of 3.8 mm. The design corresponded to the arrangement shown in Fig. 9.

[0154] Example 6: Reinforced mobile pressure measuring unit in the shape of a rounded square

[0155] A base 1 according to Example 5 was provided, but with a continuous frame 8 for the printed circuit board 6. Reinforcing struts were arranged around the frame 8 at right angles to the frame. The base 1 had a total of six recesses 10 in the edge area to facilitate and strengthen the attachment of the dome 3. There were two recesses 10 on each of three sides of the square base 1. The fourth side had no recesses for reasons of space, as sufficient space was needed on this side for the first pressure sensor 7. A printed circuit board 6 with an embedded NFC antenna 20 and both pressure sensors 12, 18 on the same side of the board was provided. The board 6 was fixed in the frame 8 using double-sided adhesive tape 2 so that the sensors 12, 18 pointed away from the base 1. The dome 3 had six pin-shaped projections 22 that were inserted flush into the recesses 10 of the base 1.Furthermore, the dome 3 had an opening 7 for the first pressure sensor and a holder 16 that separated the first pressure sensor 12 from the second pressure sensor 18 and the housing interior in a gas-tight manner. The attached dome 3 was welded to the base 1 in a gas-tight manner. The structure of this version of the mobile pressure measuring unit can be seen in Fig. 10, where the holder 16 is not shown separately but can be seen as a raised area around the opening 7.

[0156] Since in this version of the mobile pressure measuring unit the opening 7 is located in the dome 3, the measuring unit should be placed on the skin with the base 1 first so that the opening 7 is not covered by the skin during the measurements and the air exchange is maintained.

[0157] Example 7: Mobile pressure measuring unit in hexagonal form

[0158] A hexagonal base 1 made of TPE, each with the same edge length, was provided. The base 1 had a centrally positioned circular recess. The raised area around the recess formed the edge. Furthermore, the base 1 had a continuous opening 7 on its inside, extending to the outside, for the first pressure sensor 12. The circuit board 6 with the embedded NFC antenna 20 and the two sensors 12, 18 on opposite sides of the circuit board 6 was attached to the base 1 by means of a square holder 16 made of TPE, in such a way that the first pressure sensor 12 was positioned in the aforementioned opening 7. The second pressure sensor 18 was overlaid by the holder 16 but not enclosed in a gas-tight manner, so that it was in contact with the gas-filled interior of the housing 21.

[0159] The prepared base 1 was welded gas-tight to a transparent, hexagonal dome 3. The dome 3 also had a centrally aligned circular area, with the circular area projecting beyond the hexagonal edge area. This design is illustrated in Fig. 11. Example 8: Load-bearing capacity measurement of the weld seam

[0160] A mobile pressure measuring unit according to the invention was provided in a circular design (round in plan view), in which the base and dome were made of TPU and joined together by ultrasonic welding. The diameter of the circular pressure measuring unit was 53 mm. The weld seam had a width of approximately 3.1 mm and an area of ​​approximately 4.86 cm. 2 .

[0161] The base and dome were each connected with a thread, and the pressure measuring unit was clamped into a tensile machine using these two threads. Two measurements were then taken to determine the maximum possible tensile force.

[0162] In both measurements, the limiting factor was the thread's suspension. This broke in the first measurement under a load of 5.5 kg (approximately 54 N) and in the second measurement under a load of 7.0 kg (approximately 68.7 N). The pressure measurement unit remained intact and gas-tight. The applied force was insufficient to separate the base and dome after welding or to damage the weld.

[0163] The applied force in the second measurement corresponded to a pressure of approximately 225 mmHg, which was far above the usual maximum pressure for compression therapy of approximately 80 mmHg.

[0164] Example 9: Comparison of pressure measurements before and after integration of the pressure measurement unit into a bandage

[0165] Three identical mobile pressure measurement units (A, B, and C) according to the invention (each with a housing consisting of a dome and a base) and three bandages were provided. First, each pressure measurement unit was weighted down with a weight of the same mass, and the resulting pressure was measured. The measured values ​​from the first and second pressure sensors were recorded separately. Subsequently, each pressure measurement unit was wrapped in a compression bandage so that it was covered by a layer of textile material on top and bottom, and the procedure was repeated. Each measurement was performed twice (one measurement repetition). The measured values ​​are listed in Table 1 below: Table 1

[0166] The difference between the measured value of the second pressure sensor and the measured value of the first pressure sensor corresponds to the measured applied pressure as it would be determined during compression therapy. These differences and the average values ​​of the measurements are shown in Table 2:

[0167] Table 2

[0168] If we look at the deviation across all six measurements in Table 2 (two measurements each with three measurement units), we only get a difference of 6.8 mmHg - 6.2 mmHg = 0.6 mmHg. It can be seen that a pad that covers the mobile

[0169] It is clear that the effect of integrating the mobile pressure measurement unit into a bandage on the measured values ​​is negligible. Example 10: Integration of the mobile pressure measurement unit into a bandage

[0170] A mobile pressure measuring unit with a dome and base as well as electronics inside the housing were provided, as shown schematically in Fig. 13, as well as a cohesive compression bandage with a surface area of ​​10 cm x 1 m consisting of two sewn layers of nonwoven material according to the following structure: Nonwoven fabric I: thermally bonded spunbonded polyester fabric with a basis weight of 25 g / m 2

[0171] Nonwoven fabric II: thermally bonded spunbonded polyester fabric with a basis weight of 60 g / m 2

[0172] Nonwoven fabrics I and II were sewn together using the following yarn: elastane filament made of PU with a yarn count of 135 dtex. The mobile pressure measurement unit was placed on the compression bandage. Then, 18.5 cm of the compression bandage was folded over, so that there was a layer of compression bandage above and below the pressure measurement unit. A rectangular seam was then sewn around the pressure measurement unit without exerting any pressure or tension. The seam measured approximately 10 cm x 8.5 cm, maintaining a distance of several centimeters from the pressure measurement unit and preventing the pressure measurement unit from being subjected to any tensile forces exerted by the bandage in its initial state.

[0173] Short description of the drawings

[0174] Fig. 1 shows a top view of a printed circuit board 6. A first digital pressure sensor 12 is attached to the printed circuit board 6. The first pressure sensor 12 is located below the printed circuit board 6 from the viewer and is therefore shown indicated. Furthermore, a second digital pressure sensor 18 is attached to the printed circuit board 6 and, from the viewer, is located on top of the printed circuit board 6. An NFC-compatible antenna 20 in the form of a frame antenna is embedded in the printed circuit board 6. Further electronic components can be mounted on the printed circuit board 6 as required. The printed circuit board 6 shown is suitable for use in the mobile pressure measuring unit according to the invention. For example, it can be fixed to a base 1 of the pressure measuring unit.

[0175] Fig. 2 shows a plan view of an overall flat dome 3. The dome 3 is made of PU and is circular. On its outer side (facing the viewer), the dome 3 is completely covered in the circular area by a film 4 coated on both sides with skin-friendly acrylic adhesive, which is covered with a cover film 5 for protection. The cover film 5 can be removed manually via the tab 14 (tab for peeling off the cover film) immediately before the dome 3 is applied to the skin. After use, the dome 3 can be removed via the tab 15 (tab for peeling the mobile pressure measuring unit off the user's skin). The dome 3 shown is suitable for use in the mobile pressure measuring unit according to the invention. It can, for example, be connected to a base 1, to which other necessary components such as the circuit board 6 are attached.Tabs 14, 15 and adhesive film 4 are optional and increase ease of use.

[0176] Fig. 3 shows a side view of a housing 21. The housing 21 consists of a dome 3 and a base 1, which are welded together in a gas-tight manner. On the underside of the base 1 there is an opening 7 for attaching the first pressure sensor 12. The opening 7 is in the form of a protrusion and protrudes beyond the base 1. The housing 21 shown is suitable for accommodating a printed circuit board 6 and other components. The housing 21 can be placed on the skin with the dome 3 facing forward. A first pressure sensor 12 accommodated in the opening 7 remains in contact with the atmospheric air.

[0177] Fig. 4 shows a housing 21. The base 1 is facing the viewer. An opening 7 for attaching the first pressure sensor is recessed into the base 1. The opening is designed to provide the best possible protection for the pressure sensor without losing contact with the atmospheric air. Tabs 14 and 15 increase ease of use.

[0178] Fig. 5 shows the layered structure of a pressure measuring unit according to the invention. The base 1 with tab 15 is shown with its inner side facing the viewer. On this inner side is a frame 8 for inserting the printed circuit board 6. The frame 8 forms a continuous elevation on the inner side of the base 1, so that the printed circuit board 6 is flush with the frame 8. The printed circuit board 6 is connected to the base using a double-sided adhesive tape 2. The adhesive tape 2 has the same external dimensions as the printed circuit board 6, but has a recess for the first pressure sensor 12, which encloses the first pressure sensor in a gas-tight manner and prevents gas from escaping from the housing 21 through the opening 7. The first pressure sensor 12, attached to the underside of the printed circuit board 6, fits into the opening 7, which is also located within the frame 8. The second pressure sensor 18 is located on the upper side of the printed circuit board 6.An NFC-compatible antenna 20 is embedded in the circuit board 6. The detailed structure of the circuit board 6 can be seen in Figs. 1 and 10.

[0179] The base 1 is overlaid by the dome 3 and connected to it in a gas-tight manner. The dome 3 is covered on its upper side with a double-sided adhesive film 4. The upper side of the film 4 is coated with skin-compatible acrylic adhesive, which is protected by a cover film 5 that can be removed via a pull-off tab 14. After removing the cover film 5, the dome 3 can be fixed to the skin using the adhesive film 4. If the pressure measurement unit is no longer needed, it can be removed via tab 15.

[0180] Fig. 6 shows the inside of a base 1 with frame 8 and opening 7 for the first pressure sensor. The version of the base 1 shown here has reinforcing struts 9. The reinforcing struts 9 surround the frame 8 and increase the torsional rigidity of the base 1 so that the printed circuit board 6 to be inserted is better protected against bending and torsional forces. The base 1 also has recesses 10 to facilitate fastening of the dome 3 to the base 1. The associated dome 3 has a pin-shaped projection 22 for each recess 10, which ends flush with the respective recess 10 when the dome is placed on top. This facilitates the gas-tight fastening of the dome 3 to the base 1 and ensures that the dome 3 does not slip, for example during the welding process. In addition, the load-bearing capacity of the resulting housing 21 against mechanical forces is increased.

[0181] Fig. 7 shows another variant of the base 1 in an interior view. The frame 8 for the printed circuit board 6 is designed discontinuously and consists of six raised portions, all of which are flush with the printed circuit board 6 to be inserted, thus preventing the printed circuit board 6 from slipping. The discontinuous frame 8 saves material compared to a continuous frame. Furthermore, the weight of the base 1 and thus of the pressure measurement unit as a whole is reduced, making it easier to attach to the skin.

[0182] The opening 7 for mounting the first pressure sensor is surrounded by several notches 11 for filling with epoxy resin 13. After inserting the first pressure sensor, the epoxy resin 13 is filled into the notches 11, thus securing the sensor in the opening 7. The circuit board can then be inserted into the frame 8 and connected to the sensor 7.

[0183] Fig. 8 shows the same variant of the base 1 with the first pressure sensor 12 inserted and the introduction of epoxy resin 13.

[0184] Fig. 9 shows another variant of the mobile pressure measuring unit in a layered structure. In this embodiment, the pressure measuring unit is designed as a square with rounded corners when viewed from above. This creates a larger contact surface with the skin, which particularly effectively prevents the pressure measuring unit from slipping. This variant is particularly suitable for hairy skin on less mobile areas of the body. The base 1 is provided on its outside with a double-sided adhesive film 4, which is protected by a cover film 5. The cover film 5 has a tab 14. The cover film 5 can be removed via this tab 14 immediately before the mobile pressure measuring unit is stuck to the skin. The pressure measuring unit is attached to the skin with the base 1 first. The circuit board 6 is fastened to the base 1 using a double-sided adhesive tape 2.The first pressure sensor 12 and the second pressure sensor 18 are mounted on the circuit board 6. Both pressure sensors 12, 18 are located on the same side of the circuit board 6 and face the viewer. The first pressure sensor 12 is overlaid by a mount 16, thus spatially separating it from the second pressure sensor 18. The mount 16 has an opening 7 through which the first pressure sensor 12 is in contact with the atmospheric air.

[0185] The base 1 is welded to a dome 3, which has an additional elevation located above the support 16 and ensures air exchange with the first pressure sensor 12 via the opening 7.

[0186] Fig. 10 shows another variant of the mobile pressure measuring unit. Base 1 and dome 3 have the shape of a square with rounded corners when viewed from above. The first pressure sensor 12 and the second pressure sensor 18 are plugged onto the circuit board 6. The circuit board 6 also contains a microcontroller 19. Between the base 1 and the circuit board 6 there is a double-sided adhesive tape 2 (in the illustration on the underside of the circuit board 6), which fixes the circuit board 6 to the base 1. The dome 3 has pins 22 that are flush with the recesses 10 in the base 1. The first pressure sensor 12 is located in an opening 7 in the dome 3 and is in contact with the atmospheric air via this opening, whereas the second pressure sensor 18 is only in contact with the gas inside the gas-tight housing 21.

[0187] Fig. 11 shows another variant of the mobile pressure measuring unit, in which the base 1 forms a hexagon with equal sides when viewed from above. The dome 3 is transparent, allowing the printed circuit board 6 with the integrated antenna 20 to be seen within the housing 21.

[0188] Fig. 12a and 12b each show an embodiment of a spacer for the second pressure sensor.

[0189] Fig. 13 shows a circuit board with a second pressure sensor, protected by a spacer. The circuit board is connected to a round antenna with multiple windings. By arranging the antenna around the circuit board, the space inside the mobile pressure measurement unit (not shown) is optimally utilized.

Claims

Patent claims 1. A mobile pressure measuring unit for measuring the contact pressure exerted by a medical compression bandage on a patient's extremity, comprising a) a gas-tight housing 21 having a flexible dome 3 and a gas-filled cavity inside it to accommodate the contact pressure of the compression bandage applied over the housing, b) a first pressure sensor 12 communicating with the atmospheric air for measuring the external air pressure, c) a second pressure sensor 18 located within the gas-filled cavity and communicating with it for measuring the internal gas pressure in the gas-filled cavity, d) a printed circuit board 6 located in the gas-filled cavity and comprising a passive RFID transponder, wherein the printed circuit board 6 is electrically connected to the first pressure sensor 12 and the second pressure sensor 18,and wherein pressure measurements can be carried out by the pressure sensors using an RFID reader and the data thus determined can be read out wirelessly, wherein the pressure sensor 12 is at least partially embedded in the housing.

2. Mobile pressure measuring unit according to claim 1, wherein the housing has a base 1 which is opposite the flexible dome 3 and which has an inner side facing the dome 3 and an outer side opposite the inner side, wherein the base 1 and the flexible dome 3 are connected to one another in a gas-tight manner, so that the gas-filled cavity is formed between the base 1 and the flexible region 3.

3. Mobile pressure measuring unit according to claim 2, wherein the base 1 is rubber-elastic, and wherein the base has a Shore A value of 20 to 80.

4. Mobile pressure measuring unit according to claim 2 or 3, wherein the base 1 contains or is coated with silicone or a thermoplastic polyurethane.

5. Mobile pressure measuring unit according to one of claims 2 to 4, wherein the base 1 contains an opening 7 in which the first pressure sensor 12 is mounted.

6. Mobile pressure measuring unit according to claim 5, wherein the opening 7 is located in an outwardly directed protrusion of the base 1.

7. Mobile pressure measuring unit according to claim 5 or 6, wherein the first pressure sensor 12 is fixed by an epoxy resin 13 or an adhesive tape 2.

8. Mobile pressure measuring unit according to one of claims 2 to 7, wherein the circuit board 6 is attached to the inside of the base 1 and the attachment comprises an adhesive tape 2.

9. Mobile pressure measuring unit according to one of claims 2 to 8, wherein the inside of the base 1 comprises a continuous or discontinuous frame 8 for the circuit board 6.

10. Mobile pressure measuring unit according to one of claims 3 to 9, wherein the printed circuit board 6 is flexible and has a Shore A value less than or equal to the Shore A value of the base 1.

11. Mobile pressure measuring unit according to claim 10, wherein the circuit board 6 contains at least one polyimide.

12. Mobile pressure measuring unit according to one of the preceding claims, wherein the second pressure sensor 18 is located within a horseshoe-shaped, perforated or partially enclosing spacer 23 and wherein the spacer 23 is fastened to the printed circuit board 6 and has a height which projects beyond the second pressure sensor 18 in the direction of the dome 3, so that the second pressure sensor 18 is protected from direct contact with the dome 3 when the dome 3 is elastically deformed under the action of the contact pressure and consequently approaches the second pressure sensor 18.

13. Mobile pressure measuring unit according to one of the preceding claims, wherein all cables associated with the mobile pressure measuring unit are located within the housing 21.

14. Mobile pressure measuring unit according to one of the preceding claims, wherein at least the first of the two pressure sensors 12, 18 is embedded in the printed circuit board 6.

15. Mobile pressure measuring unit according to one of the preceding claims, wherein the mobile pressure measuring unit can obtain the electrical energy required to carry out a measurement from an electromagnetic field using an antenna 20 and wherein the antenna is part of the passive RFID transponder.

16. Mobile pressure measuring unit according to claim 15, wherein the antenna 20 is curved or round and has a plurality of turns.

17. Mobile pressure measuring unit according to claim 15 or 16, wherein the antenna 20 is integrated into the circuit board 6.

18. Mobile pressure measuring unit according to one of the preceding claims, wherein the flexible dome 3 consists of a single layer of substantially uniform thickness.

19. A bandage containing a mobile pressure measuring unit according to one of the preceding claims.

20. A pad according to claim 19, wherein the pad has a visual marker applied to the side of the pad that faces away from the skin during use.

21. A method for producing a mobile pressure measuring unit according to one of claims 2 to 18, comprising the following steps: a) providing the flexible dome 3, the base 1, the first and second pressure sensors 12, 18, the RFID transponder and the circuit board 6, b) fastening the circuit board 6 to the base 1, c) connecting the pressure sensors 12, 18 and the RFID transponder to the circuit board 6, the first pressure sensor 12 being in contact with the outside of the base 1 so that it can measure the ambient pressure d) welding the dome 3 to the base 1 so that a gas-tight, gas-filled cavity is formed between the dome 3 and the base 1 and so that the dome 3 and base 1 enclose the second pressure sensor 18, the transponder and the circuit board 6.

22. Method according to claim 21, wherein the welding is an ultrasonic welding, which takes place by means of a round sonotrode and wherein the dome 3 and / or the base 1 is subjected to a negative pressure generated in the round sonotrode, so that the dome 3 and / or base 1 thereby lies completely against the concave of the sonotrode surface.

23. A method for measuring a contact pressure comprising the following steps: a) Attaching the mobile pressure measuring unit according to one of claims 1 to 18 and at least one bandage to an extremity of a patient, wherein the at least one bandage is wrapped around the extremity and around the mobile pressure measuring unit in order to generate a contact pressure b) Providing an electromagnetic field by a reader for powering the mobile pressure measuring unit c) Reading out the contact pressure measured by the mobile pressure measuring unit with the reader d) Calculating the pressure value measured by the mobile pressure measuring unit or the pressure values ​​in the reader to an absolute pressure value e) Comparing the measured contact pressure with the desired contact pressure f) Optionally correcting the contact pressure by replacing, tightening or Loosening of at least one bandage and / or optionally additional bandages.

Images