Batteryless wearable ultrasonic tags and system for passive healthcare monitoring

Abstract

The present disclosure pertains to a wearable medical device for passive healthcare monitoring. The device includes an ultrasonic tag (1) attached to the user's skin, comprising an ultrasonic transducer (2) and a coil (3) electrically connected to the transducer. The transducer and coil (3) form a resonant circuit with a resonant frequency close to the working frequency of the transducer. The ultrasonic tag (1) is encapsulated in a biocompatible soft elastomer. The device is characterized by the ultrasonic tag (1) being powered by near field coupling with a transmit / receive coil (5) in close proximity to the tag.

Description

[0001] 21644.93

[0002] DESCRIPTION BATTERYLESS WEARABLE ULTRASONIC TAGS AND SYSTEM FOR PASSIVE HEALTHCARE MONITORING

[0003] Field of the Invention

[0004] The present disclosure generally relates to wearable medical devices, and more specifically, to batteryless ultrasonic tags for passive healthcare monitoring powered by near field coupling.

[0005] State of the Art

[0006] Wearable medical devices have become increasingly popular in recent years due to their potential to provide continuous, real-time monitoring of various physiological parameters. These devices often incorporate sensors that can measure parameters such as heart rate, blood pressure, and body temperature. One type of sensor that has been used in wearable medical devices is the ultrasonic sensor. Ultrasonic sensors work by emitting ultrasonic waves and then measuring the time it takes for these waves to bounce back after hitting an object. This allows the sensor to determine the distance to the object, which can be used to measure various physiological parameters.

[0007] One of the challenges with wearable medical devices is providing power to the sensors. Many devices rely on batteries to power the sensors, but batteries can be bulky and heavy, which can make the devices uncomfortable to wear. Furthermore, batteries have a limited lifespan and may require frequent replacement, which can be inconvenient for the user. To address this issue, some devices have incorporated wireless power transfer technologies, such as near field coupling, to power the sensors. Near field coupling works by transmitting power wirelessly from a power source to a receiver within a short distance.21644.93

[0008] In the field of non-destructive testing, a wireless ultrasound sensor has been disclosed in EP3311154B1. This sensor comprises an ultrasound transducer and two induction coils, which are electrically coupled to the ultrasound transducer.

[0009] Summary of the Invention

[0010] The object of the present disclosure is to provide a wearable medical device for passive healthcare monitoring. The device is intended to be used in various applications including, but not limited to, ultrasonic contact lens, blood pressure monitoring, and bladder volume monitoring.

[0011] Brief Description of the Drawing

[0012] Fig 1 shows an exemplary embodiment of the invention.

[0013] Reference Numbers:

[0014] 1. Ultrasonic tag

[0015] 2. Ultrasonic transducer

[0016] 3. Coil

[0017] 4. Biocompatible soft elastomer

[0018] 5. Transmit / receive coil

[0019] Detailed Description of the Invention

[0020] The ultrasonic tag (1) comprises an ultrasonic transducer (2) and a coil (3) that are electrically connected to each other. The ultrasonic transducer (2) and the coil (3) form a resonant circuit with a resonant frequency that is close to the working frequency of the ultrasonic transducer. The ultrasonic tag (1) is encapsulated in a biocompatible soft elastomer. The ultrasonic tag (1) is powered by near field21644.93

[0021] coupling with a transmit / receive coil (5) that is in close proximity to the ultrasonic tag (1).

[0022] The ultrasonic transducer (2) may be a Lead Zirconate Titanate (PZT) disc or plate. The ultrasonic tag (1) may further comprise a silicone-based adhesive layer for long-term adhesion to the skin. The transmit / receive coil (5) may be designed for impedance tuning and matching for maximum power transfer to the ultrasonic tag (1). The ultrasonic tag (1) may be adapted for in-vivo blood pressure monitoring or bladder volume monitoring. The ultrasonic tag (1) may also be adapted for ex- vivo axial eye length monitoring. The ultrasonic tag (1) may be powered by a Bluetooth and / or cloud-connected transmitter / receiver electronic circuitry.

[0023] The wearable medical device provides several technical advantages. By using near field coupling, the ultrasonic tag (l)s attached to the skin are powered up for measurements, eliminating the use of bulky batteries and data acquisition electronics. This makes the device more comfortable and convenient for the user. The device can be used for a variety of applications, including but not limited to ultrasonic contact lens, blood pressure monitoring, bladder volume monitoring, and axial eye length monitoring. This versatility makes the device a valuable tool in the field of healthcare monitoring.

[0024] In some aspects, the ultrasonic transducer (2) in the ultrasonic tag (1) may be a Lead Zirconate Titanate (PZT) disc or plate. PZT is a type of piezoelectric ceramic material that is known for its high dielectric constant and piezoelectric properties, which make it suitable for use in ultrasonic transducers. The use of a PZT disc or plate as the ultrasonic transducer (2) may enhance the sensitivity and efficiency of the ultrasonic tag (1), thereby improving the accuracy and reliability of the healthcare monitoring.

[0025] In some cases, the ultrasonic tag (1) may include a silicone -based adhesive layer for long-term adhesion to the skin. The adhesive layer may be designed to securely21644.93

[0026] attach the ultrasonic tag (1) to the skin of the user, ensuring that the tag remains in place during the monitoring period. This may provide a stable and consistent contact between the ultrasonic tag (1) and the skin, which is beneficial for obtaining accurate and reliable measurements. Furthermore, the use of a silicone-based adhesive may enhance the comfort and wearability of the ultrasonic tag (1), as silicone is known for its skin-friendly properties, including its flexibility, breathability, and hypoallergenic nature.

[0027] In some embodiments, the transmit / receive coil (5) may be designed for impedance tuning and matching for maximum power transfer to the ultrasonic tag (1). Impedance matching is a technique used in electronics to maximize the power transfer between devices by making the output impedance of one device equal to the input impedance of the other. In the context of the wearable medical device, impedance matching may be used to optimize the power transfer from the transmit / receive coil (5) to the ultrasonic tag (1), thereby ensuring that the tag is sufficiently powered for its operation. This may enhance the efficiency and performance of the device, while also reducing power consumption and extending battery life.

[0028] In conclusion, the wearable medical device for passive healthcare monitoring provides several technical advantages. By utilizing an ultrasonic tag (1) with a PZT ultrasonic transducer (2) and a silicone-based adhesive layer, the device offers high sensitivity, reliable measurements, and comfortable wearability. Furthermore, the use of impedance matching in the transmit / receive coil (5) enhances the power transfer to the ultrasonic tag (1), improving the efficiency and performance of the device. These features make the wearable medical device a valuable tool for a wide range of healthcare monitoring applications.

[0029] In some cases, the ultrasonic tag (1) may be powered by a Bluetooth and / or cloud-connected transmitter / receiver electronic circuitry. This type of circuitry can wirelessly transmit power to the ultrasonic tag (1), as well as receive data from the21644.93

[0030] tag. The use of Bluetooth and / or cloud connectivity allows for real-time data transmission and remote monitoring, which can be beneficial in healthcare applications where continuous monitoring and immediate response are desired. For instance, in the case of blood pressure monitoring, the data collected by the ultrasonic tag (1) can be instantly transmitted to a healthcare provider or a monitoring system, allowing for immediate intervention in case of abnormal readings.

[0031] In other aspects, the wearable medical device itself may be powered by a Bluetooth and / or cloud-connected transmitter / receiver electronic circuitry. This allows for the device to be wirelessly powered and controlled, enhancing its usability and convenience. The wireless power supply can eliminate the use of bulky batteries in the device, making it more lightweight and comfortable for the user. Furthermore, the use of Bluetooth and / or cloud connectivity allows for real-time data transmission and remote control of the device, which can be beneficial in healthcare applications where continuous monitoring and immediate response are desired. In conclusion, the wearable medical device for passive healthcare monitoring provides several technical advantages. By utilizing near field coupling and Bluetooth and / or cloud-connected transmitter / receiver electronic circuitry, the device offers wireless power supply and real-time data transmission, enhancing its usability and convenience. Furthermore, the use of an ultrasonic tag (1) with a PZT ultrasonic transducer (2) and a silicone-based adhesive layer offers high sensitivity, reliable measurements, and comfortable wearability. These features make the wearable medical device a valuable tool for a wide range of healthcare monitoring applications.

[0032] In some embodiments, the ultrasonic transducer (2) in the ultrasonic tag (1) may be a piezocomposite or any other piezoceramic. Piezocomposites and other piezoceramics are materials that exhibit piezoelectric properties, meaning they can generate an electric charge in response to applied mechanical stress. This property makes them suitable for use in ultrasonic transducers, which operate by converting21644.93

[0033] electrical signals into mechanical vibrations and vice versa. The use of a piezocomposite or other piezoceramic as the ultrasonic transducer (2) may provide flexibility in the design and fabrication of the ultrasonic tag (1), as these materials can be tailored to meet specific performance requirements. For instance, piezocomposites can offer improved acoustic impedance matching with biological tissues, which can enhance the efficiency of ultrasonic energy transfer and improve the quality of the measurements obtained.

[0034] In some cases, the ultrasonic transducer (2) may be a Lead Zirconate Titanate (PZT) disc or plate. PZT is a type of piezoceramic that is known for its high dielectric constant and strong piezoelectric effect, which make it an excellent material for use in ultrasonic transducers. The use of a PZT disc or plate as the ultrasonic transducer (2) may enhance the sensitivity and efficiency of the ultrasonic tag (1), thereby improving the accuracy and reliability of the healthcare monitoring. Furthermore, PZT materials are robust and durable, which can contribute to the longevity and reliability of the wearable medical device.

[0035] In conclusion, the wearable medical device for passive healthcare monitoring provides several technical advantages. By utilizing an ultrasonic tag (1) with a piezocomposite, PZT, or other piezoceramic ultrasonic transducer, the device offers high sensitivity, reliable measurements, and flexible design options. Furthermore, the use of near field coupling and Bluetooth and / or cloud-connected transmitter / receiver electronic circuitry enhances the device's usability and convenience by providing wireless power supply and real-time data transmission. These features make the wearable medical device a valuable tool for a wide range of healthcare monitoring applications.

[0036] In some embodiments, the ultrasonic tag (1) of the wearable medical device may include a silicone-based adhesive layer for long-term adhesion to the skin. The adhesive layer may be designed to securely attach the ultrasonic tag (1) to the skin of the user, ensuring that the tag remains in place during the monitoring period. This may provide a stable and consistent contact between the ultrasonic tag (1) and the21644.93

[0037] skin, which is beneficial for obtaining accurate and reliable measurements. Furthermore, the use of a silicone-based adhesive may enhance the comfort and wearability of the ultrasonic tag (1), as silicone is known for its skin-friendly properties, including its flexibility, breathability, and hypoallergenic nature.

[0038] In other cases, the wearable medical device itself may further comprise a silicone-based adhesive layer for long-term adhesion to the skin. This adhesive layer may be applied to the outer surface of the device, allowing it to be securely attached to the skin of the user. The use of a silicone-based adhesive layer in the wearable medical device can enhance the stability and reliability of the device, as it ensures that the device remains in place during the monitoring period. This can be particularly beneficial in applications where continuous and long-term monitoring is desired, as it allows for consistent and uninterrupted data collection.

[0039] In conclusion, the inclusion of a silicone-based adhesive layer in the ultrasonic tag (1) and the wearable medical device provides several technical advantages. By ensuring secure and long-term adhesion to the skin, the adhesive layer enhances the stability and reliability of the healthcare monitoring, leading to more accurate and reliable measurements. Furthermore, the use of a silicone-based adhesive enhances the comfort and wearability of the device, making it more user-friendly and suitable for long-term use. These features contribute to the overall effectiveness and usability of the wearable medical device for passive healthcare monitoring.

[0040] In some embodiments, the transmit / receive coil (5) of the wearable medical device may be designed for impedance tuning and matching for maximum power transfer to the ultrasonic tag (1). Impedance matching is a technique used in electronics to maximize the power transfer between devices by making the output impedance of one device equal to the input impedance of the other. In the context of the wearable medical device, impedance matching may be used to optimize the power transfer from the transmit / receive coil (5) to the ultrasonic tag (1), thereby ensuring that the tag is sufficiently powered for its operation. This may enhance the efficiency and21644.93

[0041] performance of the device, while also reducing power consumption and extending battery life.

[0042] In conclusion, the design of the transmit / receive coil (5) for impedance tuning and matching for maximum power transfer to the ultrasonic tag (1) provides several technical advantages. By optimizing the power transfer and enabling wireless power supply, the design enhances the efficiency, performance, and usability of the wearable medical device. Furthermore, it contributes to the device's lightweight and comfortable design, making it more user-friendly and suitable for long-term use. These features make the wearable medical device a valuable tool for a wide range of healthcare monitoring applications.

[0043] In conclusion, the functional adaptations of the ultrasonic tag (1) for in-vivo blood pressure monitoring or bladder volume monitoring provide several technical advantages. By providing non-invasive, continuous, and real-time monitoring of blood pressure and bladder volume, the ultrasonic tag (1) enhances the usability and effectiveness of the wearable medical device. Furthermore, these adaptations contribute to the versatility of the device, making it a valuable tool for a wide range of healthcare monitoring applications.

[0044] In other cases, the ultrasonic tag (1) may be used for ex-vivo testing on cow eyes for axial eye length monitoring. Cow eyes are often used in ophthalmic research due to their similarity to human eyes in terms of size and structure. The ultrasonic tag (1) may be attached to the surface of the cow eye and used to measure the axial length in a similar manner as described above. The use of the ultrasonic tag (1) for ex-vivo testing on cow eyes may provide a valuable tool for ophthalmic research, contributing to the development of new treatments and interventions for eye conditions.

[0045] In conclusion, the adaptation of the ultrasonic tag (1) for ex-vivo axial eye length monitoring provides several technical advantages. By providing non-invasive,21644.93

[0046] accurate, and real-time monitoring of axial eye length, the ultrasonic tag (1) enhances the usability and effectiveness of the wearable medical device in ophthalmic applications. Furthermore, the use of the ultrasonic tag (1) for ex-vivo testing on cow eyes contributes to ophthalmic research, paving the way for the development of new treatments and interventions for eye conditions. These features make the wearable medical device a valuable tool for a wide range of healthcare monitoring and research applications.

[0047] In some embodiments, the ultrasonic tag (1) is embedded inside a biocompatible soft elastomer (4) using a mold. The ultrasonic transducer (2)and the coil (3), which form the core components of the ultrasonic tag (1), are placed inside the mold. A biocompatible soft elastomer, such as Poly(methylhydrosiloxane), is then poured into the mold, encapsulating the ultrasonic transducer (2) and the coil (3). This process ensures that the ultrasonic tag (1) is fully encapsulated within the elastomer, providing a protective layer that shields the tag from external factors and enhances its durability. Furthermore, the use of a biocompatible soft elastomer (4) enhances the comfort and wearability of the ultrasonic tag (1), as the elastomer is soft and flexible, conforming to the contours of the skin.

[0048] In other cases, for skin adhesion, medical skin adhesive tape or sticky silicone for wearables can be drop casted or adhered to one face of the ultrasonic tag (1). The adhesive layer ensures that the ultrasonic tag (1) remains securely attached to the skin during the monitoring period, providing a stable and consistent contact between the tag and the skin. This is beneficial for obtaining accurate and reliable measurements, as it minimizes the potential for movement or displacement of the tag that could affect the quality of the measurements. Furthermore, the use of medical skin adhesive tape or sticky silicone enhances the comfort and wearability of the ultrasonic tag (1), as these materials are known for their skin-friendly properties, including their flexibility, breathability, and hypoallergenic nature.21644.93

[0049] In conclusion, the process of embedding the ultrasonic tag (1) inside a biocompatible soft elastomer (4) using a mold and adhering the tag to the skin using medical skin adhesive tape or sticky silicone for wearables provides several technical advantages. By ensuring the durability, stability, and comfort of the ultrasonic tag (1), these processes enhance the usability and effectiveness of the wearable medical device for passive healthcare monitoring. These features make the wearable medical device a valuable tool for a wide range of healthcare monitoring applications.

[0050] In other cases, the system operates as if the piezoelement is excited with wires when the coil (3)s are aligned to each other, even when the ultrasonic tag (1) is embedded inside a biocompatible soft elastomer. The elastomer provides a protective layer that shields the ultrasonic tag (1) from external factors, while also allowing the magnetic field generated by the transmit / receive coil (5) coil to reach the coil (3) of the ultrasonic tag (1). This ensures that the piezoelement can be excited even when the ultrasonic tag (1) is fully encapsulated within the elastomer, enhancing the durability and reliability of the system.

[0051] In conclusion, the operational aspect of the system where the piezoelement is excited with wires when the coil (3) s are aligned to each other provides several technical advantages. By enabling on-demand excitation of the piezoelement and ensuring the durability and reliability of the system, this operational aspect enhances the efficiency, performance, and longevity of the wearable medical device for passive healthcare monitoring. These features make the wearable medical device a valuable tool for a wide range of healthcare monitoring applications.

[0052] In conclusion, the potential for other applications of the ultrasonic tag (1), such as blood flow monitoring and stomach filling monitoring, provides several technical advantages. By providing non-invasive, continuous, and real-time monitoring of blood flow and stomach filling, the ultrasonic tag (1) enhances the versatility and effectiveness of the wearable medical device. Furthermore, these adaptations21644.93

[0053] contribute to the wide applicability of the device, making it a valuable tool for a broad range of healthcare monitoring applications.

[0054] In general, the wearable medical device and the system for passive healthcare monitoring offer several technical advantages and benefits. The batteryless design of the ultrasonic tag (1), powered by near field coupling or Bluetooth and / or cloud-connected transmitter / receiver electronic circuitry, contributes to the lightweight and comfortable nature of the device. This can potentially improve patient comfort and convenience, particularly for long-term monitoring applications.

[0055] Moreover, the device's ability to monitor various physiological parameters, such as blood pressure, bladder volume, and axial eye length, in a non-invasive manner, can provide valuable data for healthcare providers. This can facilitate timely intervention and better management of various health conditions.

[0056] Furthermore, the versatility of the device, as demonstrated by its adaptability for other applications like blood flow monitoring and stomach filling monitoring, broadens its potential use in the healthcare field. This makes the wearable medical device a valuable tool for a wide range of healthcare monitoring applications.

[0057] In conclusion, the wearable medical device for passive healthcare monitoring, as described herein, offers a novel and effective solution for non-invasive, continuous, and real-time monitoring of various physiological parameters. Its technical advantages and benefits, including its lightweight and comfortable design, versatility, and broad applicability, make it a valuable tool in the field of healthcare monitoring.

Claims

21644.93CLAIMS1. A wearable medical device for passive healthcare monitoring, comprising: an ultrasonic tag (1) attached to the skin of a user,the ultrasonic tag (1) (1) comprising an ultrasonic transducer (2) and a coil (3) electrically connected to the ultrasonic transducer (2), wherein the ultrasonic transducer (2) and the coil (3) form a resonant circuit with a resonant frequency close to the working frequency of the ultrasonic transducer (2);anda biocompatible soft elastomer (4) encapsulating the ultrasonic transducer (2) and the coil (3), characterised in that, the ultrasonic tag (1) is powered by near field coupling with a transmit / receive coil (5) in close proximity to the ultrasonic tag (1).

2. The wearable medical device of claim 1, wherein the ultrasonic transducer (2) is a Lead Zirconate Titanate (PZT) disc or plate.

3. The wearable medical device of claim 1 or 2, wherein the ultrasonic tag (1) further comprises a silicone-based adhesive layer for long-term adhesion to the skin.

4. The wearable medical device of any preceding claim, wherein the transmit / receive coil (5) is designed for impedance tuning and matching for maximum power transfer to the ultrasonic tag (1).

5. The wearable medical device of any preceding claim, wherein the ultrasonic tag (1) is adapted for in-vivo blood pressure monitoring or bladder volume monitoring.

6. The wearable medical device of any preceding claim, wherein the ultrasonic tag (1) is adapted for ex-vivo axial eye length monitoring.21644.

937. The wearable medical device of any preceding claim, wherein the ultrasonic tag (1) is powered by a Bluetooth and / or cloud-connected transmitter / receiver electronic circuitry.

8. A system for passive healthcare monitoring, comprising:a wearable medical device as claimed in claim 1 ;anda transmit / receive coil (5) designed to power up the ultrasonic tag (1) of the wearable medical device by near field coupling,characterised in that the transmit / receive coil (5) includes an electronic circuitry with impedance matching and tuning for the ultrasonic tag (1).

9. The system of claim 8, wherein the wearable medical device is adapted for in- vivo blood pressure monitoring or bladder volume monitoring.

10. The system of claim 9, wherein the wearable medical device further comprises a silicone-based adhesive layer for long-term adhesion to the skin.

11. The system of any one of claims 8 to 10, wherein the wearable medical device is powered by a Bluetooth and / or cloud-connected transmitter / receiver electronic circuitry.

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