Flexible electronic health monitoring devices and systems

Abstract

The present application relates to health monitoring technical field, its purpose is to provide a kind of flexible electronic health monitoring device and system, to be fused into flexible health monitoring system in indoor level wireless power supply technology, technical scheme can be summarized as: flexible electronic health monitoring device, including flexible antenna, rectifier module, monitoring sensor module, flexible dielectric substrate and encapsulation layer, wherein, each module is interconnected by flexible electrical connection between and in it and is arranged on flexible dielectric substrate, for necessary small rigid device setting local rigid island, then overall encapsulation is formed encapsulation layer, and flexible antenna is flexible microstrip antenna, rectifier module stores the input electric energy by the form of capacitor and is powered for monitoring sensor module.A beneficial effect is that meter-level energy supply is achieved, and it is suitable for health monitoring system.

Description

Technical Field

[0001] This invention relates to the field of health monitoring technology, and in particular to a flexible electronic health monitoring device and system. Background Technology

[0002] In recent years, wearable health monitoring devices have seen rapid development in medical and home settings. However, traditional battery charging and wired power supply methods have led to problems such as increased size and maintenance burdens, insufficient wearing comfort, and inconvenience in long-term continuous monitoring. To address these issues, far-field (radiating) wireless power transfer technology has gradually gained attention. Unlike near-field coupling methods, which can only achieve power transfer within a millimeter to centimeter range, far-field WPT (wireless power transfer) generally uses microwave transmission and microstrip antenna reception, enabling meter-level or even longer-range power supply in ISM bands such as 915MHz, 2.4GHz, or 5.8GHz, adapting to the free-moving areas of hospital wards and homes. Currently, commercial platforms such as Powercast (915MHz) and Ossia Cota (2.4GHz) have been developed and have passed FCC technical certification, verifying the feasibility of indoor wireless power supply. However, the microstrip antennas used in these solutions are mainly designed for rigid or semi-rigid device forms and have not yet been effectively coupled with "fully flexible wearable systems". They have obvious shortcomings in terms of fit and comfort, and cannot directly meet the needs of skin-tight and long-term health monitoring.

[0003] To achieve skin-friendly, low-profile, and stretchable properties, academia and industry widely employ printing / spraying processes such as silver paste, conductive nanowires, PEDOT:PSS (an aqueous solution of a polymer composed of poly(3,4-ethylenedioxythiophene) PEDOT and polystyrene sulfonate PSS), or liquid metallic inks to construct flexible / stretchable circuits and magnetically coupled coils on elastic substrates such as TPU (thermoplastic polyurethane elastomer), SEBS (linear triblock copolymer), Ecoflex (biodegradable plastic), and PDMS (polydimethylsiloxane), exploring the miniaturization and wearability of these systems. Meanwhile, research on "biosymbiotic" devices also demonstrates the feasibility of achieving wireless and low-intervention long-term operation in home environments through digital manufacturing of customized geometric and mechanical interfaces. However, in general, most "fully flexible wearable" prototypes are still mainly powered by batteries / wired connections, or only at the level of short-range energy coupling and short-range communication using magnetically coupled coils. In real home / hospital environments, there are still engineering challenges that need to be systematically addressed, such as energy harvesting and power management under compliant power density and EIRP constraints, heterogeneous integration of rigid chips and stretchable conductive networks, interconnection and packaging reliability under sweat / humid heat / repeated deformation, and the collaborative design of indoor coverage and duty-free energy storage strategies.

[0004] Therefore, for hospital wards and home environments with free movement, there is an urgent need for a fully flexible wireless power supply health monitoring system that uses a flexible and stretchable substrate as its core, combines a stretchable conductive network with rigid-flexible heterogeneous interconnects, and forms an integrated design path from transmitter deployment and link budget to receiver rectification / energy storage / voltage regulation, data backhaul, and thin packaging, while meeting public exposure limits (such as ICNIRP) and regulatory constraints. In terms of manufacturing, liquid metal conductive ink formulations and mask / screening / spraying processes should be preferred to ensure high conductivity, stretchability, and consistency, achieving high fit, comfort, and long-term stable indoor continuous health monitoring.

[0005] In summary, the existing technology does not address the issue of a fully flexible health monitoring system with indoor wireless power supply. Summary of the Invention

[0006] The purpose of this invention is to provide a flexible electronic health monitoring device and system that integrates indoor wireless power supply technology into the flexible health monitoring system.

[0007] In the technical solution adopted by the present invention to solve the above-mentioned technical problems, in a first aspect, a flexible electronic health monitoring device is provided, including a flexible antenna, a rectifier module, a monitoring and sensing module, a flexible dielectric substrate and an encapsulation layer. The flexible antenna, rectifier module and monitoring and sensing module are provided with multiple local rigid islands for supporting the required antenna feed points and small rigid devices. The flexible antenna is flexibly electrically connected to the rectifier module and the rectifier module is flexibly electrically connected to the monitoring and sensing module. The flexible antenna, rectifier module and monitoring and sensing module are disposed on the flexible dielectric substrate. The encapsulation layer is a flexible encapsulation layer that encapsulates the flexible dielectric substrate on which the flexible antenna, rectifier module and monitoring and sensing module are disposed. The flexible antenna is a flexible microstrip antenna, used to receive electrical energy transmitted wirelessly from external devices in the far field of radio frequency and transmit it to the rectifier module. The rectifier module is used to store the input electrical energy in the form of a capacitor and to power the monitoring and sensing module. The monitoring and sensing module is used to collect relevant monitoring data and send the monitoring data to external devices.

[0008] In some embodiments, to provide a feasible small rigid device, the small rigid device includes a resistor, capacitor, inductor, Schottky diode, voltage regulator chip, sensor chip, and control chip.

[0009] In some embodiments, to provide a feasible flexible electrical connection, the flexible antenna is flexibly connected to the rectifier module, and the rectifier module is flexibly connected to the monitoring and sensing module. When it involves the flexible electrical connection between a local rigid island and a flexible device, an interconnecting material with rheological viscosity and conductivity is used for the flexible electrical connection. The conductive lines between other devices and within each device are flexibly connected through a flexible conductive material.

[0010] In some embodiments, to provide a feasible interconnect material with rheological viscosity and conductivity, the interconnect material with rheological viscosity and conductivity includes: a liquid metal composite adhesive or a conductive adhesive.

[0011] In some embodiments, to provide a feasible flexible antenna, the flexible antenna employs a conductive layer made of a flexible conductive material.

[0012] In some embodiments, to provide a feasible flexible dielectric substrate, the flexible dielectric substrate is a TPU (thermoplastic polyurethane elastomer), Ecoflex (biodegradable plastic), PDMS (polydimethylsiloxane), or SEBS (linear triadic copolymer) elastomer film.

[0013] In some embodiments, to provide a feasible flexible conductive material, the flexible conductive material is formed by spraying, screen printing, aerosol printing, or transfer processes using liquid metal ink and / or silver paste and / or conductive nanofibers and / or PEDOT:PSS (an aqueous solution of a polymer composed of poly(3,4-ethylenedioxythiophene) PEDOT and polystyrene sulfonate PSS).

[0014] In some embodiments, to provide a feasible method for preparing a flexible conductive material, the method for preparing the flexible conductive material includes: A first quantity of indium bismuth tin (InBiSn) alloy and a second quantity of isopropanol (IPA) are heated to obtain a heated solution; The heated solution was placed in an ultrasonic cell disruptor, the operating parameters of the ultrasonic cell disruptor were set and the operation was carried out. After the operation was completed, the solution was allowed to settle and then dried to obtain low melting point alloy particles with a thin oxide layer formed on them. Low-melting-point alloy particles are mixed with liquid gallium indium tin (GaInSn) in hydrochloric acid of the third concentration to remove the thin oxide layer on the low-melting-point alloy particles, forming a uniform metallic ink, which is then dried to remove acid. After drying and deacidifying, the metallic ink is coated or printed using laser cutting of stainless steel or polyester templates or screen printing techniques. Then, it undergoes low-temperature activation and mechanical wetting or light pressing to obtain a flexible conductive material of the corresponding shape.

[0015] In some embodiments, to provide a feasible method for preparing a flexible conductive material, the method for preparing the flexible conductive material includes: The flexible dielectric substrate was ultrasonically treated with ethanol and deionized water in sequence, dried, and then subjected to plasma cleaning. A silver nanowire suspension prepared with silver nanowires (AgNWs) and isopropanol was used to lay a bottom layer network on a flexible dielectric substrate. Then, a liquid metal microcapsule (LMMs) suspension prepared with isopropanol was sprayed onto the bottom layer network to form a superimposed structure. The flexible dielectric substrate is inverted and suspended above the surface of concentrated hydrochloric acid at a distance of 1. HCl-vapor treatment is performed to remove the oxide layer of the liquid metal microcapsules, causing the liquid metal microcapsules to rupture and release liquid metal, which diffuses and reactively wets the underlying network formed by the silver nanowires, forming a hybrid conductive layer in which the silver nanowires are embedded in the liquid metal film. A flexible conductive material embedded in a flexible dielectric substrate is obtained by drying the flexible dielectric substrate.

[0016] In some embodiments, to provide a feasible rectifier module, the rectifier module includes a first surface-mount capacitor, a second surface-mount capacitor, a first rectifier diode, a second rectifier diode, and a power management chip. One end of the first surface-mount capacitor is flexibly electrically connected to the output terminal of the flexible antenna. The other end of the first surface-mount capacitor is flexibly electrically connected to the positive terminal of the first rectifier diode and the negative terminal of the second rectifier diode. The negative terminal of the first rectifier diode is flexibly electrically connected to one end of the second surface-mount capacitor. The positive terminal of the second rectifier diode is flexibly electrically connected to the other end of the second surface-mount capacitor. The positive terminal of the second rectifier diode is also flexibly electrically connected to the output terminal of the flexible antenna. Both ends of the second surface-mount capacitor are flexibly electrically connected to the input terminal of the power management chip, outputting rectified DC power to the power management chip. The power management chip regulates the rectified DC power before outputting it.

[0017] In some embodiments, due to the instability of indoor wireless power supply, in order to save power and ensure the operation of the monitoring sensor module, the power management chip regulates the output of the rectified DC power supply, including: The power management chip performs voltage regulation and output after the voltage of the second surface-mount capacitor reaches a first preset value, and shuts off the output when the voltage of the second surface-mount capacitor falls below a second preset value.

[0018] In some embodiments, due to the instability of indoor wireless power supply, the monitoring sensor module may not have completed one sampling, processing, and data transmission cycle. That is, during a full cycle of operation of the monitoring sensor module, there may be cases where the data is not fully processed. In such cases, the capacitance value of the first patch capacitor must be at least greater than or equal to a preset capacitance value, and the formula for calculating the preset capacitance value is as follows: ; Among them, E burst V represents the energy required for a single full-cycle operation of the monitoring sensor module. H V is the first preset value. L As the second preset value, C SYS This is the preset capacitance value.

[0019] In some embodiments, to provide a feasible monitoring and sensing module, the monitoring and sensing module includes: a control chip, a biosensor, and a patch Bluetooth antenna, wherein the biosensor and the patch Bluetooth antenna are flexibly electrically connected to the control chip, and the control chip is flexibly electrically connected to the rectifier module.

[0020] In some embodiments, since modules such as monitoring and sensing modules may require the implementation of conductive paths between upper and lower layers on the flexible dielectric substrate and the encapsulation layer, the flexible dielectric substrate and the encapsulation layer may also include conductive vias to enable interlayer conductivity.

[0021] In some embodiments, the encapsulation layer is formed by spin-coating or dip-coating an elastomeric prepolymer compatible with a flexible dielectric substrate.

[0022] In a second aspect, the technical solution adopted by the present invention to solve the above-mentioned technical problems provides a flexible electronic health monitoring system, including a power supply end, a data receiving end, and the flexible electronic health monitoring device as described above. The power supply end includes a power amplifier module and a radio frequency transmitting antenna. The power amplifier module is electrically connected to the radio frequency transmitting antenna and is used to radiate electromagnetic waves to form an indoor energy field with meter-level coverage. The flexible electronic health monitoring device receives energy from the energy field through a flexible antenna, and outputs the energy to the monitoring and sensing module through a rectifier module to power the monitoring and sensing module. The monitoring and sensing module collects the corresponding monitoring data and sends it to the data receiving end.

[0023] The beneficial effects of this invention are that, in the solution of this invention, a flexible antenna can receive electrical energy transmitted from radio frequency far-field wireless transmission, thereby achieving meter-level power supply, overcoming the shortcomings of near-field coupling which is limited to millimeter or centimeter range for power supply, and adopting a capacitor power supply method, eliminating the need for a large storage battery. At the same time, the rigid-flexible heterogeneous form formed by the use of local rigid islands, flexible electrical connections, and flexible antennas ensures system stability without hindering the user's free movement, making it suitable for long-term wear. Attached Figure Description

[0024] Figure 1 This is a schematic system block diagram of the flexible electronic health monitoring device in an embodiment of the present invention.

[0025] Figure 2 This is a schematic topology diagram of the flexible electronic health monitoring device in an embodiment of the present invention.

[0026] Figure 3 This is a schematic topology diagram of another flexible electronic health monitoring device in an embodiment of the present invention.

[0027] Figure 4 This is a schematic circuit diagram of the rectifier module in an embodiment of the present invention.

[0028] Figure 5 This is a schematic timing diagram of the flexible antenna, rectifier module, and monitoring sensor module in an embodiment of the present invention.

[0029] Figure 6 This is a schematic system block diagram of the flexible electronic health monitoring system in an embodiment of the present invention.

[0030] Figure 7 This is a schematic diagram of the reflection coefficient measurement of the flexible antenna under uniaxial stretching along the length direction in an embodiment of the present invention.

[0031] Figure 8 This is a schematic diagram of the reflection coefficient measurement of the flexible antenna under uniaxial stretching along the width direction in an embodiment of the present invention.

[0032] Figure 9 This is a schematic diagram of the reflection coefficient measurement of the flexible antenna under the condition of bending along the length direction in an embodiment of the present invention.

[0033] Figure 10 This is a schematic diagram of the reflection coefficient measurement of the flexible antenna under the condition of bending along the width direction in an embodiment of the present invention. Detailed Implementation

[0034] The technical solution of the present invention will now be described in detail with reference to the embodiments and accompanying drawings.

[0035] like Figure 1 and Figure 2 As shown, in a first aspect, this invention provides a flexible electronic health monitoring device, including a flexible antenna, a rectifier module, a monitoring and sensing module, a flexible dielectric substrate, and an encapsulation layer. The flexible antenna, rectifier module, and monitoring and sensing module are provided with multiple local rigid islands for supporting the required antenna feed points and small rigid devices. The flexible antenna is flexibly electrically connected to the rectifier module, and the rectifier module is flexibly electrically connected to the monitoring and sensing module. The flexible antenna, rectifier module, and monitoring and sensing module are disposed on the flexible dielectric substrate. Here, the encapsulation layer is a flexible encapsulation layer, which encapsulates the flexible dielectric substrate on which the flexible antenna, rectifier module and monitoring sensor module are installed. The flexible antenna is a flexible microstrip antenna used to receive electrical energy transmitted wirelessly from external devices in the far field of radio frequency and transmit it to the rectifier module; The rectifier module is used to store the input electrical energy in the form of capacitors and to power the monitoring and sensing modules. The monitoring sensor module is used to collect relevant monitoring data and send the monitoring data to external devices.

[0036] It is understandable that small rigid devices can include electrical components that cannot be made of flexible materials, such as resistors, capacitors, inductors, Schottky diodes, voltage regulator chips, sensor chips, and control chips.

[0037] In some embodiments, to provide a feasible flexible electrical connection, the flexible electrical connection between the flexible antenna and the rectifier module, and the flexible electrical connection between the rectifier module and the monitoring and sensing module, can specifically be as follows: when it involves the flexible electrical connection between a local rigid island and a flexible device, an interconnecting material with rheological viscosity and conductivity is used for the flexible electrical connection, and the conductive lines between other devices and within each device are connected by a flexible conductive material.

[0038] It is understandable that in the above embodiments, local rigid islands are set up to achieve full flexibility of the entire flexible electronic health monitoring device. The flexible electrical connection between these local rigid islands and ordinary flexible devices has certain unique characteristics. Therefore, interconnecting materials with rheological viscosity and conductivity are used for flexible electrical connections, such as liquid metal composite adhesives or conductive adhesives. The flexible devices and other components mentioned here can be the various components that make up the flexible antenna, rectifier module, and monitoring sensor module, such as the flexible radiating element of the flexible antenna, the ground plane, the patch capacitors and related chips used in the rectifier module and monitoring sensor module.

[0039] In some embodiments, to provide a feasible flexible antenna, the flexible antenna may employ a flexible conductive material to fabricate a conductive layer.

[0040] It is understandable that the flexible antenna here is a flexible microstrip antenna, which includes a radiating element, related connecting wires, and a ground layer, all of which are conductive layers.

[0041] In some embodiments, to provide a feasible flexible dielectric substrate, the flexible dielectric substrate may be an elastomer film such as TPU (thermoplastic polyurethane elastomer), Ecoflex (biodegradable plastic), PDMS (polydimethylsiloxane), or SEBS (linear triadic copolymer).

[0042] In addition, since flexible antennas and monitoring and sensing modules may require the implementation of conductive paths between upper and lower layers on the flexible dielectric substrate and encapsulation layer, such as the radiating element and ground layer of the flexible antenna being respectively set on the upper and lower sides of the flexible dielectric substrate, and a sensor in the monitoring and sensing module needing to contact the human body through a contact point formed by conductive material, the flexible dielectric substrate and encapsulation layer may also include conductive vias to achieve interlayer conduction.

[0043] Furthermore, when the radiating element, rectifier module, and monitoring sensor module of the flexible antenna are located on the upper side of the flexible dielectric substrate, the ground plane can be located on the lower side of the flexible dielectric substrate and extend to the lower side of the flexible dielectric substrate corresponding to the rectifier module and the monitoring sensor module. That is, the projection of the rectifier module and / or the monitoring sensor module on the lower side of the flexible dielectric substrate can be covered by the ground plane. Figure 3 As shown, it can isolate the radiating element of the flexible antenna from human skin, ensuring energy transmission efficiency and protecting the human body from electromagnetic radiation, while also providing a system ground wire.

[0044] In some embodiments, to provide a feasible flexible conductive material, the flexible conductive material may be formed by spraying, screen printing, aerosol printing, or transfer processes using liquid metal ink and / or silver paste and / or conductive nanofibers and / or PEDOT:PSS (an aqueous solution of a polymer composed of poly(3,4-ethylenedioxythiophene) PEDOT and polystyrene sulfonate PSS).

[0045] The following are two methods for preparing flexible conductive materials: The first method for preparing flexible conductive materials includes: A first quantity of indium bismuth tin (InBiSn) alloy and a second quantity of isopropanol (IPA) are heated to obtain a heated solution. Here, the content of the indium bismuth tin (InBiSn) alloy can be 51% indium, 32.5% bismuth and 16.5% tin, and the first quantity and the second quantity can preferably be in a ratio of 1 gram: 5 milliliters, such as the first quantity being 2 grams and the second quantity being 10 milliliters. At the same time, during heating, the first quantity of indium bismuth tin (InBiSn) alloy and the second quantity of isopropanol (IPA) can be heated through a hot plate at 70°C.

[0046] The heated solution was placed in an ultrasonic cell disruptor, and the operating parameters of the ultrasonic cell disruptor were set and run. After the operation was completed, the mixture was allowed to settle for a short period of time, and then dried to obtain low-melting-point alloy particles with a thin oxide layer formed on them. Here, the operating parameters of the ultrasonic cell disruptor can be set as follows: power set to 600W, running for 30 minutes; the initial time can be 6 hours; and drying can specifically be carried out at 40℃ for 12 hours. Because a thin oxide layer forms on the low-melting-point alloy particles, they are easy to store and disperse.

[0047] Low-melting-point alloy particles are mixed with gallium indium tin (GaInSn) liquid metal in a third-concentration hydrochloric acid (HCl) solution to remove the thin oxide layer on the low-melting-point alloy particles, forming a uniform metallic ink, which is then dried to remove acid. Here, the third concentration can be 1 mol / L; and the drying and acid removal can specifically be carried out at 40°C. Furthermore, the content of the gallium indium tin liquid metal can be 68.5% gallium, 21.5% indium, and 10% tin, and the mass ratio of low-melting-point alloy particles to gallium indium tin liquid metal can be 2:1. This ratio allows the final flexible conductive material to achieve a good balance between conductivity and stretchability. Simultaneously, the rheology and printability can be tuned by increasing or decreasing the amount of low-melting-point alloy particles. This metallic ink is an all-metal system that maintains high conductivity. The thin oxide layer on the low-melting-point alloy particles is removed by using hydrochloric acid, which allows the low-melting-point alloy particles to fuse with the gallium indium tin liquid metal, improving contact and the connectivity of electronic channels. It can still have a continuous conductive path under large strain, so it is suitable for flexible interconnects and antenna feed lines.

[0048] After drying and deacidifying, the metallic ink is coated or printed using laser-cut stainless steel stencils or polyester stencils or screen printing techniques. Then, it undergoes low-temperature activation and mechanical wetting or light pressing to obtain a flexible conductive material of the corresponding shape. Here, low-temperature activation can be carried out at 40-60℃.

[0049] This flexible conductive material can be used as a low sheet resistance and stretchable conductive trace and microstrip antenna pattern. It has good compatibility with flexible dielectric substrates formed by elastomer films such as TPU (thermoplastic polyurethane elastomer), Ecoflex (biodegradable plastic), PDMS (polydimethylsiloxane), or SEBS (linear tri-block copolymer). It can also be combined with vias to form the above-mentioned conductive vias and achieve low-stress interconnection with local rigid islands.

[0050] The second method for preparing flexible conductive materials includes: The flexible dielectric substrate is ultrasonically treated with ethanol and deionized water in sequence, then dried, and then plasma cleaned. The ultrasonic treatment time can be 10 minutes, that is, the flexible dielectric substrate is ultrasonically treated with ethanol for 10 minutes, and then ultrasonically treated with deionized water for 10 minutes. The plasma cleaning time can be 120 seconds, the purpose of which is to improve adhesion and wetting.

[0051] A silver nanowire suspension prepared with silver nanowires (AgNWs) and isopropanol was deposited as a base network on a flexible dielectric substrate. Then, an LMMs suspension prepared with liquid metal microcapsules (LMMs) and isopropanol was sprayed onto the base network to form a superimposed structure. Here, the concentration of the silver nanowire suspension prepared with silver nanowires and isopropanol can be 0.5 mg / mL, and the concentration of the LMMs suspension prepared with liquid metal microcapsules and isopropanol can be 1 mg / mL. In this superimposed structure, the silver nanowires are located between the liquid metal microcapsules and the flexible dielectric substrate.

[0052] A flexible dielectric substrate is inverted and suspended above a concentrated hydrochloric acid solution at a first distance. HCl-vapor treatment is then applied to remove the oxide layer of the liquid metal microcapsules, causing them to rupture and release liquid metal. This liquid metal diffuses and reactively wets the underlying network formed by silver nanowires, creating a hybrid conductive layer in which the silver nanowires are embedded in the liquid metal film. Here, the concentration of concentrated hydrochloric acid can be 36-38 wt%, and the first distance can be 1 cm. The HCl-vapor treatment time can be 10 seconds.

[0053] The flexible dielectric substrate is dried to obtain a flexible conductive material embedded in the flexible dielectric substrate; here, the drying process can be: placing the flexible dielectric substrate in an environment of 35°C and drying for 4 hours.

[0054] In this method, it is important to note that excessive use of liquid metal microcapsules can lead to corrosion or "internalization" of the silver nanowires, resulting in cracks and increased resistance. Conversely, insufficient use can expose the silver nanowires, allowing hydrochloric acid to corrode them and generate silver chloride, further increasing resistance. Therefore, the liquid metal microcapsules should be applied in appropriate amounts to completely cover the silver nanowires while ensuring that cracking is controllable.

[0055] The flexible conductive material prepared by this method combines the advantages of a high aspect ratio network of silver nanowires and a continuous thin film of liquid metal microcapsules. Its adhesion, chemical stability, and mechanical stability are superior to those of bare silver nanowires, making it suitable for long-term applications of flexible antennas or flexible interconnects.

[0056] The flexible conductive materials generated by the two methods can also be applied to different modules. For example, the antenna radiating surface can use the flexible conductive material generated by the second method, while the conductive via can use the flexible conductive material generated by the first method. They can also be combined according to actual performance requirements.

[0057] In some embodiments, the rectifier module may employ low-threshold Schottky diodes to form a full-wave or voltage doubler rectifier structure, such as... Figure 4 As shown, the rectifier module may include a first surface-mount capacitor, a second surface-mount capacitor, a first rectifier diode, a second rectifier diode, and a power management chip. One end of the first surface-mount capacitor is flexibly electrically connected to the output terminal of the flexible antenna. The other end of the first surface-mount capacitor is flexibly electrically connected to the positive terminal of the first rectifier diode and the negative terminal of the second rectifier diode. The negative terminal of the first rectifier diode is flexibly electrically connected to one end of the second surface-mount capacitor. The positive terminal of the second rectifier diode is flexibly electrically connected to the other end of the second surface-mount capacitor. The positive terminal of the second rectifier diode is also flexibly electrically connected to the output terminal of the flexible antenna. Both ends of the second surface-mount capacitor are flexibly electrically connected to the input terminal of the power management chip, outputting rectified DC power to the power management chip. The power management chip regulates the rectified DC power before outputting it.

[0058] It is understood that the first surface-mount capacitor serves as an energy storage capacitor, while the second surface-mount capacitor serves as a load capacitor. Furthermore, surface-mount capacitors are well-suited for use on flexible dielectric substrates, connecting to other devices via stretchable conductors (i.e., flexible electrical connections), thus making them a good fit for the flexible electronic health monitoring device in this embodiment of the invention. The power management chip can employ a low-dropout linear regulator or a buck-boost converter for regulated output.

[0059] Meanwhile, due to the instability of indoor wireless power supply, in order to save power and ensure the operation of the monitoring sensor module, the power management chip regulates the output of the rectified DC power supply, which may include: The power management chip performs voltage regulation and output after the voltage of the second surface-mount capacitor reaches a first preset value, and shuts off the output when the voltage of the second surface-mount capacitor falls below a second preset value.

[0060] Understandably, when the voltage is regulated, the energy stored in the first surface-mount capacitor begins to be consumed; when the output is turned off, the first surface-mount capacitor continues to store energy. In other words, the power management chip uses a duty cycle-energy storage mechanism to smoothly handle intermittent or unevenly received energy from the far field.

[0061] Due to the instability of indoor wireless power supply, the monitoring sensor module may not have completed one sampling, processing, and data transmission cycle. Therefore, the capacitance value of the first patch capacitor must be at least greater than or equal to the preset capacitance value. The formula for calculating the preset capacitance value is as follows: ; Among them, E burst V represents the energy required for a single full-cycle operation of the monitoring sensor module. H V is the first preset value. L As the second preset value, C SYS This is the preset capacitance value.

[0062] In order to make the energy stored in the first surface mount capacitor more consistent with the required energy consumption and the existing fault tolerance range, and to avoid the first surface mount capacitor becoming larger due to the capacitance value being set too high, the capacitance value of the first surface mount capacitor is preferably set to be greater than the preset capacitance value and less than or equal to 3 times the preset capacitance value.

[0063] A schematic timing diagram of the flexible antenna, rectifier module, and monitoring sensor module of the flexible electronic health monitoring device is shown below. Figure 5 As shown, the input power represents the unstable input power received by the flexible antenna, and its fluctuations reflect signal variations caused by distance, obstruction, and multipath effects in the actual environment. Peak periods indicate sufficient energy, while trough periods indicate insufficient energy.

[0064] The energy storage capacitor C1 refers to the first surface-mount capacitor, which directly responds to input power fluctuations, acting as an energy buffer and temporary storage device to smooth out instability in the input energy. The load capacitor C2 refers to the second surface-mount capacitor, whose amplitude exhibits a typical sawtooth waveform, reaching a threshold value of V. H Second preset value V L Periodic fluctuations, threshold line V H and V L It serves as a threshold control function; the high threshold V is marked by a gray dashed line. H (i.e., system startup voltage) and low threshold V L (i.e., system shutdown voltage), constituting the voltage window for system operation, C m This represents the maximum amplitude of the energy storage capacitor C1, and t represents time. For ease of understanding, we use 1, 2, 3... to represent the time interval, which is not the standard 1 second, 2 seconds...

[0065] The system operating status indicates the operating status of the subsequent monitoring and sensing module. This monitoring and sensing module may include a control chip, a biosensor, and a patch Bluetooth antenna. Here, the biosensor and patch Bluetooth antenna are flexibly electrically connected to the control chip, which is flexibly electrically connected to the rectifier module. Figure 5In the system operating status section, a high level indicates that the monitoring and sensing module is in working condition, and its control chip, biosensor, and patch Bluetooth antenna are powered on to perform data acquisition, processing, and transmission tasks; while a low level indicates that the monitoring and sensing module is in sleep mode (i.e., system sleep mode), at which time only the rectifier module is working to minimize power consumption and accumulate energy.

[0066] The key timing relationships are shown in Table 1.

[0067] Table 1. Key Timing Correspondence Table

[0068] As can be seen, the energy storage capacitor C1 effectively smooths out fluctuations in input power, ensuring continuous energy collection even when the RF signal is weak. The system represented by the monitoring sensor module only operates when the voltage of the load capacitor C2 is between the first preset value VH and the second preset value VL, ensuring sufficient energy for each operation. A complete monitoring process, including sampling, processing, and data transmission, is strictly limited to the time window when energy is sufficient, thereby ensuring the reliability of data transmission. Furthermore, the system's operating frequency automatically adapts to the input energy intensity, operating frequently when energy is sufficient and extending the system's sleep time when energy is scarce. This design enables coordinated energy-to-data management that maintains periodic and reliable data transmission even in extremely unstable energy harvesting environments.

[0069] In the above embodiments, the encapsulation layer can be formed by spin coating or dip coating of an elastomer prepolymer compatible with the flexible dielectric substrate. The thickness of the encapsulation layer can be 50-300μm. It can adopt a partitioned encapsulation and stress relief design to improve reliability under sweat and / or humid heat and / or repeated deformation environments.

[0070] The fabrication method of the entire flexible electronic health monitoring device can then be as follows: First, a flexible dielectric substrate is prepared. Existing spin coating or casting methods can be used to prepare elastomer films such as TPU, Ecoflex, PDMS, or SEBS on the flexible substrate. Then, the flexible antenna and each conductive path are formed according to the two methods mentioned above, and the via positions for conductive vias and local rigid islands are reserved. Then, small rigid devices such as diodes, capacitors, inductors and various chips are mounted on the local rigid islands. After the holes are opened by laser or mechanical means, they are filled with flexible conductive materials from the above two methods to form conductive vias, thus completing the interlayer conduction. The encapsulation layer is created by spin coating or dip coating, and a stress relief structure is designed in the boundary area.

[0071] like Figure 6As shown, in a second aspect of this invention, a flexible electronic health monitoring system is provided, including a power supply end, a data receiving end, and a flexible electronic health monitoring device as described above. The power supply end includes a power amplifier module and a radio frequency transmitting antenna. The power amplifier module is electrically connected to the radio frequency transmitting antenna and is used to radiate electromagnetic waves to form an energy field with meter-level coverage indoors. The flexible electronic health monitoring device receives energy from an energy field through a flexible antenna, and outputs the energy to the monitoring and sensing module through a rectifier module to power the monitoring and sensing module. The monitoring and sensing module collects the corresponding monitoring data and sends it to the data receiving end.

[0072] Here, the frequency band of the radiated electromagnetic waves should be 915 MHz, 2.4 GHz, or 5.8 GHz to achieve meter-level coverage, and the transmission power and EIRP should form an indoor energy field with meter-level coverage while meeting regulatory and public exposure (MPE) limits. The data receiving end can be a terminal such as a mobile phone or computer.

[0073] In the actual constructed environment, the following results were obtained: With an EIRP ≤ 36 dBm, a receiving antenna gain of approximately 6 dBi, and indoor coverage of 3-6 m, the system's regulated output fluctuation is ≤ ±5%, and the average output power can reach 20-500 μW (depending on the field strength). This provides power for intermittent backhaul between low-power sensing modules such as ECG (chest electrocardiogram), PPG (photoplethysmography), IMU (inertial measurement unit), and pressure sensors, and Bluetooth. Under conditions of 0-60% lateral or longitudinal uniaxial tension and 90° bending deformation, the system can achieve the following results: Figure 7 , Figure 8 , Figure 9 and Figure 10 As shown, S 11 This represents the reflection coefficient, and frequency represents the receiving frequency. Figure 7 The uniaxial tension along the length direction described in the text refers to, for example... Figure 2 In the plane formed by the flexible antenna shown, the direction from the flexible antenna to the rectifier module is the length direction. A uniaxial stretch is performed with the centerline of the flexible antenna perpendicular to the length direction as the axis. Figure 7 The table shows the reflection coefficient of the flexible antenna when stretched by 0% (i.e., no stretching), 20% (i.e., the flexible antenna is stretched to 120% in the length direction), 40% (i.e., the flexible antenna is stretched to 140% in the length direction), and 60% (i.e., the flexible antenna is stretched to 160% in the length direction). Figure 8 The uniaxial tension along the width direction mentioned in the text refers to, for example... Figure 2 In the plane formed by the flexible antenna shown, the direction perpendicular to the aforementioned length direction is the width direction, with the main body of the flexible antenna (i.e. Figure 3The uniaxial stretching of the radiating element (with the centerline in the width direction as the axis) is performed. Figure 8 The table shows the reflection coefficient of the flexible antenna when stretched by 0% (i.e., no stretching), 20% (i.e., the flexible antenna is stretched to 120% in the width direction), 40% (i.e., the flexible antenna is stretched to 140% in the width direction), and 60% (i.e., the flexible antenna is stretched to 160% in the width direction). Figure 9 The bending along the length direction mentioned above refers to fixing one end of the flexible antenna along the aforementioned length direction and bending the other end; the included angle between the two ends is the bending angle. Figure 9 The reflection coefficients of the flexible antenna are marked for bending angles of 0°, 30°, 60° and 90°. Figure 10 The bending along the width direction mentioned above refers to fixing one end of the flexible antenna in the aforementioned width direction and bending the other end; the included angle between the two ends is the bending angle. Figure 10 The reflection coefficients of the flexible antenna are marked at bending angles of 0°, 30°, 60°, and 90°. It can be seen that the reflection coefficient of the flexible antenna consistently remains below -10 dB, thus ensuring stable energy reception. Furthermore, the system maintains stable interconnect and packaging performance under conditions exceeding 10,000 stretching / bending cycles and in sweat / humid heat environments.

[0074] Because flexible electronic health monitoring devices are diverse, they may include low-power sensing modules such as ECG (chest electrocardiogram) and / or PPG (photoplethysmography) and / or IMU (inertial sensing) and / or pressure sensors, each corresponding to different flexible electronic health monitoring devices and their application scenarios, such as: In the context of chest electrocardiogram monitoring: The flexible electronic health monitoring device is attached to the anterior chest wall (fourth intercostal space on the left sternal border) of the monitored person for real-time electrocardiogram signal acquisition and wireless transmission.

[0075] The flexible antenna is integrated onto a flexible dielectric substrate. The rectifier module is located in the low-strain region next to the sternum; A monitoring and sensing module is formed by integrating biosensors and control chips on the surface of a flexible dielectric substrate for electrocardiogram signal acquisition. The health monitoring sensor module processes electrocardiogram signals through a control chip and transmits them wirelessly via a Bluetooth antenna.

[0076] The work process is as follows: When the transmitter emits radio frequency energy at 915 MHz or 2.4 GHz, the flexible antenna on the chest receives the energy and provides stable DC power through the rectifier module. The ECG electrodes (belonging to biosensors) are attached to the skin to collect ECG signals in real time. After being amplified and filtered by other components in the monitoring and sensing module, the signals are transmitted to the data receiver via Bluetooth antenna by the control chip.

[0077] In the scenario of walking rehabilitation monitoring in a hospital ward: It is necessary to monitor the gait and exercise intensity of the monitored individuals; The power supply can be placed at both ends of the ward, using 2.4 GHz or 5.8 GHz directional antennas with EIRP=36-40dBm, to ensure that the receiving end is always within the coverage area during movement; The flexible antenna is attached to the outside of the patient's lower leg or near the knee joint; The rectifier module is located in the low-strain region of the lower leg and is connected to the circuitry of the flexible antenna and monitoring sensor module via conductive vias and flexible electrical connections. The biosensors in the monitoring and sensing module collect acceleration and pressure signals, which are then processed by the control chip and uploaded in real time to the nurse station terminal (i.e., the data receiving end) via Bluetooth antenna.

[0078] The work process is as follows: When patients walk or perform rehabilitation training in the ward, the flexible antenna maintains stable energy collection under stretching and bending conditions. After being converted and regulated by the rectifier module, it continuously supplies power to the monitoring sensor module, ensuring the real-time acquisition and transmission of gait signals and motion data.

Claims

1. A flexible electronic health monitoring device, characterized in that, The device includes a flexible antenna, a rectifier module, a monitoring and sensing module, a flexible dielectric substrate, and a packaging layer. The flexible antenna, rectifier module, and monitoring and sensing module are provided with multiple local rigid islands to support the required antenna feed points and small rigid devices. The flexible antenna is flexibly electrically connected to the rectifier module, and the rectifier module is flexibly electrically connected to the monitoring and sensing module. The flexible antenna, rectifier module, and monitoring and sensing module are disposed on the flexible dielectric substrate. The packaging layer is a flexible packaging layer that encapsulates the flexible dielectric substrate on which the flexible antenna, rectifier module, and monitoring and sensing module are disposed. The flexible antenna is a flexible microstrip antenna, used to receive electrical energy transmitted wirelessly from external devices in the far field of radio frequency and transmit it to the rectifier module. The rectifier module is used to store the input electrical energy in the form of a capacitor and to power the monitoring and sensing module. The monitoring and sensing module is used to collect relevant monitoring data and send the monitoring data to external devices.

2. The flexible electronic health monitoring device as described in claim 1, characterized in that, In the flexible electrical connection between the flexible antenna and the rectifier module, and the flexible electrical connection between the rectifier module and the monitoring and sensing module, when it involves the flexible electrical connection between the local rigid island and the flexible device, an interconnecting material with rheological viscosity and conductivity is used for the flexible electrical connection. The conductive lines between other devices and within each device are flexibly connected by flexible conductive materials.

3. The flexible electronic health monitoring device as described in claim 2, characterized in that, The interconnecting material with rheological viscosity and conductivity includes: liquid metal composite adhesive or conductive adhesive.

4. The flexible electronic health monitoring device as described in claim 2, characterized in that, The flexible antenna uses a flexible conductive material to make the conductive layer.

5. The flexible electronic health monitoring device as described in claim 4, characterized in that, The flexible conductive material is formed by spraying, screen printing, aerosol printing, or transfer processes using liquid metal ink and / or silver paste and / or conductive nanofibers and / or PEDOT:PSS.

6. The flexible electronic health monitoring device as described in claim 5, characterized in that, The method for preparing the flexible conductive material includes: A first quantity of indium bismuth tin alloy and a second quantity of isopropanol are heated to obtain a heated solution. The heated solution was placed in an ultrasonic cell disruptor, the operating parameters of the ultrasonic cell disruptor were set and the operation was carried out. After the operation was completed, the solution was allowed to settle and then dried to obtain low melting point alloy particles with a thin oxide layer formed on them. Low-melting-point alloy particles are mixed with gallium indium tin liquid metal in hydrochloric acid of the third concentration to remove the thin oxide layer on the low-melting-point alloy particles, forming a uniform metal ink, which is then dried and deacidified. After drying and deacidifying, the metallic ink is coated or printed using laser cutting of stainless steel or polyester templates or screen printing techniques. Then, it undergoes low-temperature activation and mechanical wetting or light pressing to obtain a flexible conductive material of the corresponding shape.

7. The flexible electronic health monitoring device as described in claim 5, characterized in that, The method for preparing the flexible conductive material includes: The flexible dielectric substrate was ultrasonically treated with ethanol and deionized water in sequence, dried, and then subjected to plasma cleaning. A silver nanowire suspension prepared with silver nanowires and isopropanol was used to lay a bottom layer network on a flexible dielectric substrate. Then, a liquid metal microcapsule suspension prepared with isopropanol was sprayed onto the bottom layer network to form a superimposed structure. The flexible dielectric substrate is inverted and suspended above the surface of concentrated hydrochloric acid at a distance of 1. HCl-vapor treatment is performed to remove the oxide layer of the liquid metal microcapsules, causing the liquid metal microcapsules to rupture and release liquid metal, which diffuses and reactively wets the underlying network formed by the silver nanowires, forming a hybrid conductive layer in which the silver nanowires are embedded in the liquid metal film. A flexible conductive material embedded in a flexible dielectric substrate is obtained by drying the flexible dielectric substrate.

8. The flexible electronic health monitoring device according to any one of claims 1-7, characterized in that, The rectifier module includes a first surface-mount capacitor, a second surface-mount capacitor, a first rectifier diode, a second rectifier diode, and a power management chip. One end of the first surface-mount capacitor is flexibly electrically connected to the output terminal of the flexible antenna. The other end of the first surface-mount capacitor is flexibly electrically connected to the positive terminal of the first rectifier diode and the negative terminal of the second rectifier diode. The negative terminal of the first rectifier diode is flexibly electrically connected to one end of the second surface-mount capacitor. The positive terminal of the second rectifier diode is flexibly electrically connected to the other end of the second surface-mount capacitor. The positive terminal of the second rectifier diode is also flexibly electrically connected to the output terminal of the flexible antenna. Both ends of the second surface-mount capacitor are flexibly electrically connected to the input terminal of the power management chip, outputting rectified DC power to the power management chip. The power management chip regulates the rectified DC power before outputting it.

9. The flexible electronic health monitoring device as described in claim 8, characterized in that, The power management chip regulates the rectified DC power supply before outputting it, including: The power management chip performs voltage regulation and output after the voltage of the second surface-mount capacitor reaches a first preset value, and shuts off the output when the voltage of the second surface-mount capacitor falls below a second preset value.

10. A flexible electronic health monitoring system, characterized in that, Includes a power supply end, a data receiving end, and a flexible electronic health monitoring device as described in any one of claims 1-9; The power supply end includes a power amplifier module and a radio frequency transmitting antenna. The power amplifier module is electrically connected to the radio frequency transmitting antenna and is used to radiate electromagnetic waves to form an indoor energy field with meter-level coverage. The flexible electronic health monitoring device receives energy from the energy field through a flexible antenna, and outputs the energy to the monitoring and sensing module through a rectifier module to power the monitoring and sensing module. The monitoring and sensing module collects the corresponding monitoring data and sends it to the data receiving end.

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