Body surface pressure monitoring device based on flexible patch

Abstract

The invention discloses a body surface pressure monitoring device based on a flexible patch, and belongs to the field of detection equipment. The device comprises a pressure sensor array, a main control module, a Bluetooth module, a power management module and an air pressure sensor. Each pressure sensor in the pressure sensor array is arranged on the independent flexible substrate layer, and the main control module, the Bluetooth module, the power management module and the air pressure sensor are arranged on the printed circuit board and serve as control panels. The pressure sensors are connected through flexible snakelike wires which can be telescopically bent, and the pressure sensors and the control panel are connected through flexible snakelike wires which can be telescopically bent. The device has the function of monitoring body surface pressure distribution, surface pressure is converted into air pressure in the closed cavity through soft silica gel for measurement, real-time pressure data can be sent to terminal equipment, visualization of pressure distribution is achieved, and a guardian can more accurately evaluate the risk degree of pressure injury of a patient.

Description

Technical Field

[0001] The invention belongs to the field of detection equipment, and in particular relates to a body surface pressure monitoring device based on a flexible patch. Background Art

[0002] Pressure injury refers to localized damage to the skin and / or subcutaneous tissue caused by severe, prolonged pressure or pressure combined with shear force. It can manifest as deep tissue damage or open ulcers in intact skin, which may be accompanied by pain. Traditional methods of detecting pressure injuries mainly rely on the observation and judgment of medical staff and use risk assessment tools for screening, but this method is susceptible to subjective factors and may be misjudged. To quantify the risk of pressure injuries, an effective method is to use electronic technology to non-invasively monitor skin surface pressure.

[0003] Existing surface pressure monitoring devices are mainly composed of sensor patches and back-end processing modules. When patients wear the patch, their skin will directly contact the sensor element, which may cause discomfort; although it can measure pressure, it can only measure single-point pressure and cannot reflect the pressure distribution in the area. Therefore, a more comfortable and soft device that can intuitively reflect the pressure distribution in the monitoring area is needed. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects in the prior art and provide a body surface pressure monitoring device based on a flexible patch.

[0005] The specific technical solutions adopted by the present invention are as follows:

[0006] The present invention provides a body surface pressure monitoring device based on a flexible patch, comprising a pressure sensor array, a main control module, a Bluetooth module, a power management module and an air pressure sensor;

[0007] The main control module controls the multiplexing chip through the communication interface and receives the digital signals from the pressure sensor and the air pressure sensor, and transmits them to the Bluetooth module through the serial port after processing;

[0008] The Bluetooth module transmits data to the terminal device in the form of low-power Bluetooth data packets;

[0009] The power management module is used to supply power to the pressure sensor array, the main control module and the Bluetooth module;

[0010] The pressure sensor array is used to monitor the pressure distribution on the surface of human skin;

[0011] The air pressure sensor is used to measure the atmospheric pressure;

[0012] Each pressure sensor in the pressure sensor array is arranged on an independent flexible substrate layer, the main control module, Bluetooth module, power management module and air pressure sensor are arranged on a printed circuit board and serve as a control board, and each pressure sensor and the pressure sensor and the control board are connected by a retractable and bendable flexible serpentine wire.

[0013] Preferably, the interface between the pressure sensor array and the control board is a gold finger.

[0014] Preferably, the Bluetooth module includes a low-power Bluetooth system-on-chip chip and its peripheral circuits and a Bluetooth antenna, and the low-power Bluetooth system-on-chip chip integrates a microcontroller, a serial interface and a Bluetooth RF transceiver; the Bluetooth module is used to receive data from the main control module and then transmit it to the terminal device through low-power Bluetooth technology.

[0015] Preferably, the main control module includes a microcontroller and a multiplexing chip. The microcontroller selects the channel of the multiplexing chip and communicates with the sensor on the corresponding channel bus, and sends the data to the Bluetooth module after processing. The communication method between the multiplexing chip and the pressure sensor and the microprocessor is I2C.

[0016] Preferably, the pressure sensor array is a 4×4 array based on an island bridge structure design, and each measuring unit includes a digital pressure sensor and a hemispherical soft silicone shell; the pressure sensors are distributed on the upper surface of the flexible base layer, and are covered with a soft silicone shell on the outside to form a closed cavity, and the soft silicone shell is adhered and fixed to the upper surface of the flexible base layer; when the hemispherical outer surface of the soft silicone contacts the skin, it deforms when under pressure, causing the air pressure in the closed cavity to change; the surface pressure of the soft silicone is obtained by taking the difference between the cavity air pressure value measured by the pressure sensor and the atmospheric pressure measured by the air pressure sensor.

[0017] Preferably, the power management module includes a lithium battery and a DC-DC low-voltage difference linear voltage regulator circuit, and the lithium battery is adhered to the back of the control board; the DC-DC low-voltage difference linear voltage regulator circuit converts the battery voltage into a DC power supply voltage to power the main control module, and powers the Bluetooth module and the pressure sensor array through the main control module.

[0018] Preferably, the air pressure sensor communicates directly with the microcontroller of the main control module via an I2C interface.

[0019] Preferably, the overall structure and circuit routing of the serpentine conductor both adopt a serpentine design of a semicircular arc plus a straight line.

[0020] Preferably, the flexible patch formed by the pressure sensor array adopts a double-layer board structure; electrical components and wiring are distributed on the upper surface of the base layer, and wiring is distributed on the lower surface, and the two surfaces are electrically connected in the form of vias.

[0021] Preferably, the material of the base layer is flexible polyimide.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The device of the present invention has the function of monitoring the distribution of body surface pressure. It converts the surface pressure into the air pressure in a closed cavity for measurement through soft silicone, and can send real-time pressure data to a terminal device to realize visualization of the pressure distribution, so that the monitoring personnel can more accurately assess the risk level of pressure injury of the patient. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The figure is a front schematic diagram of a printed circuit board (PCB) of a pressure sensor array of the present invention.

[0025] Figure 2 It is a planar structural diagram of the flexible serpentine conductor of the present invention.

[0026] Figure 3 It is a functional block diagram of the present invention.

[0027] Figure 4 It is a schematic diagram of the soft silica gel shell structure of the present invention. DETAILED DESCRIPTION

[0028] The present invention is further described and illustrated below in conjunction with the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention can be combined accordingly without conflicting with each other.

[0029] The present invention provides a body surface pressure monitoring device based on a flexible patch, which mainly includes a pressure sensor array, a main control module, a Bluetooth module, a power management module and an air pressure sensor. Among them, the pressure sensor array includes multiple pressure sensors, each of which is arranged on an independent flexible substrate layer. The main control module, the Bluetooth module, the power management module and the air pressure sensor are all arranged on a printed circuit board, collectively referred to as a control board. The pressure sensors and the pressure sensors and the control board are connected by a flexible serpentine wire that can be retracted and bent, so that they can fit on the skin surface and have certain bending and ductility.

[0030] In a preferred embodiment of the present invention, the interface between the pressure sensor array and the control board is a gold finger.

[0031] The functions of each module in the monitoring device are briefly described as follows:

[0032] The main control module controls the multiplexing chip through the communication interface and receives the digital signals from the pressure sensor and the air pressure sensor, and transmits them to the Bluetooth module through the serial port after processing. In a preferred embodiment of the present invention, the main control module includes a microcontroller and a multiplexing chip, the microcontroller selects the channel of the multiplexing chip and communicates with the sensor on the corresponding channel bus, and sends the data to the Bluetooth module after processing; the communication mode between the multiplexing chip and the pressure sensor and the microprocessor is I2C.

[0033] The Bluetooth module transmits data to the terminal device in the form of low-power Bluetooth data packets. In a preferred embodiment of the present invention, the Bluetooth module includes a low-power Bluetooth system-on-chip chip and its peripheral circuits and a Bluetooth antenna, and the low-power Bluetooth system-on-chip chip integrates a microcontroller, a serial interface and a Bluetooth radio frequency transceiver; the Bluetooth module is used to receive data from the main control module and then transmit it to the terminal device through low-power Bluetooth technology.

[0034] The power management module is used to supply power to the pressure sensor array, the main control module and the Bluetooth module. In a preferred embodiment of the present invention, the power management module includes a lithium battery and a DC-DC low voltage drop linear voltage regulator circuit. The lithium battery is attached to the back of the control board; the DC-DC low voltage drop linear voltage regulator circuit converts the battery voltage into a DC power supply voltage to supply power to the main control module, and supplies power to the Bluetooth module and the pressure sensor array through the main control module.

[0035] Pressure sensor array, used to monitor the pressure distribution on the surface of human skin.

[0036] The air pressure sensor is used to measure the atmospheric pressure. In a preferred embodiment of the present invention, the air pressure sensor directly communicates with the microcontroller of the main control module through an I2C interface.

[0037] In a preferred embodiment of the present invention, the pressure sensor array is a 4×4 array based on an island bridge structure design, that is, the pressure sensor array is composed of 16 independent measurement units, each of which includes a digital pressure sensor and corresponding peripheral resistors and capacitors, which are designed as independent "island" structures, and each measurement unit is interconnected by a serpentine wire, see Figure 1 As shown. Specifically, the pressure sensor is distributed on the upper surface of the flexible base layer, and a soft silicone shell is provided on the outside to form a closed cavity, and the soft silicone shell is adhered and fixed to the upper surface of the flexible base layer. In actual use, when the hemispherical outer surface of the soft silicone contacts the skin, it deforms when under pressure, causing the air pressure in the closed cavity to change; the surface pressure of the soft silicone is obtained by the difference between the cavity air pressure value measured by the pressure sensor and the atmospheric pressure measured by the air pressure sensor.

[0038] In a preferred embodiment of the present invention, the flexible patch composed of the pressure sensor array adopts a double-layer board design, the upper surface of the base layer is distributed with electrical components and wiring, the lower surface is distributed with wiring, and the two sides are electrically connected in the form of vias. Specifically, the material of the base layer can be a flexible polyimide (PI) material, and the thickness can be as thin as 0.3 mm. The flexible patch in this embodiment can be attached to the skin using a medical polyurethane film.

[0039] In a preferred embodiment of the present invention, see Figure 2 As shown, the overall structure and circuit routing of the serpentine wire adopt a serpentine design of semicircular arc plus straight line, that is, the bending position is connected by semicircular arc wire, and the rest of the position is connected by straight wire, which has the characteristics of stretchability and bendability. It should be noted that this is only one implementation method, and the specific routing method can be adjusted according to actual conditions as long as it can ensure conformal contact between the patch and the skin.

[0040] The specific forms of the functional modules of the device of the present invention will be described in detail below through embodiments.

[0041] Example

[0042] The functional modules of the whole device can be found in Figure 3 shown.

[0043] Among them, the Bluetooth module should include a low-power Bluetooth system-on-chip (BLE SoC) and its peripheral circuits and Bluetooth antenna. The low-power Bluetooth system-on-chip integrates a microcontroller, a serial interface and a Bluetooth RF transceiver, which is used to receive digital signals from the main control module and transmit them to the terminal device through low-power Bluetooth technology.

[0044] The Bluetooth module in this embodiment can be the minimum system module and its peripheral circuits supporting the development of embedded systems, such as the CC2541 of Texas Instruments, or it can be an integrated Bluetooth serial communication module, such as the HC-08 of Guangzhou Huicheng Company, to simplify the circuit design. HC-08 is a data transmission module based on the low-power Bluetooth (BLE) 4.0 protocol. It uses the CC2540 chip of Texas Instruments, integrates an 8051 microcontroller, 256KB FLASH, a 2.4-GHz Bluetooth radio frequency transceiver and two serial ports, and can communicate with the main controller on the control board through the serial port. After the two HC-08 modules are connected, they enter the serial port transparent transmission mode, and the master and slave devices can directly use the serial port to send and receive data.

[0045] The main control module includes a microcontroller and its peripheral circuits, and a multiplexing chip. The multiplexing chip is used to expand I2C communication, allowing multiple I2C devices to communicate with the microcontroller through a single I2C bus. Each channel of the multiplexing chip can connect to multiple slave devices with different addresses, and the microcontroller can choose to communicate with the device of a specific channel.

[0046] The microcontroller in the embodiment is STM32F103 from STMicroelectronics, and the multiplexing chip is TCA9548A from Texas Instruments. The TCA9548A device is equipped with eight bidirectional conversion switches that can be controlled via the I2C bus. The pressure sensor can be configured with two different addresses through a pull-down resistor, so two pressure sensors can be connected to one channel of the TCA9548A, and only one TCA9548A is needed to realize the communication between the microcontroller and 16 pressure sensors in the array.

[0047] The pressure sensor array is a 4×4 array based on an island bridge structure design. Each measuring unit includes a digital pressure sensor and a hemispherical soft silicone shell. The digital pressure sensor is independently welded on the upper surface of the base layer, and the hemispherical soft silicone shell is adhered to the upper surface of the base layer to form a closed cavity.

[0048] The digital pressure sensor in the embodiment is DPS310 from Infineon Technologies, which can measure pressure and temperature simultaneously. The signal processor inside the DPS310 can convert the measurement results of the pressure and temperature sensors into 24-bit signed bit signals, which are read through the I2C interface. By configuring the pull-down resistor of the pin, two different communication addresses can be set.

[0049] The soft silicone shell in the embodiment is made by 3D printing technology, with an elastic modulus of 120 kPa, an inner diameter of the silicone shell of 7 mm, a wall thickness of 0.8 mm, and is evenly distributed on a plane in the form of an array, corresponding to each pressure sensor, see Figure 4 shown.

[0050] The independent air pressure sensor in the embodiment is DPS310 produced by Infineon, which is used to measure the atmospheric pressure and directly communicates with the microcontroller through an I2C interface.

[0051] The power management module includes a lithium battery and a DC-DC low-voltage dropout linear regulator circuit (LDO), wherein the lithium battery is attached to the back of the control board, and the DC-DC low-voltage dropout linear regulator circuit converts the battery voltage into a DC power supply voltage (+3.3V) to power the main control module, and the Bluetooth module and the pressure sensor array are powered through the main control module.

[0052] The LDO in the embodiment may be TPS782 from Texas Instruments, which is a low dropout voltage regulator capable of converting 3.7V of a lithium battery to 3.3V.

[0053] When the flexible patch is attached to the human body, the surface of the soft silicone spherical shell contacts the skin, and the air pressure changes when it is compressed. The gauge pressure can be calculated as the difference between the air pressure in the cavity and the external atmospheric pressure. However, considering the temperature and the restoring force generated when the soft silicone is deformed, the measured pressure value needs to be calibrated. The pressure sensors in the array transmit the pressure and temperature measurement values ​​to the main control module in turn. After receiving the data from the 16 pressure sensors, the microprocessor reads the atmospheric pressure value measured by the air pressure sensor on the control board once. After the above data is processed, it is sent to the Bluetooth module through the serial port. The Bluetooth module sends the data to the Bluetooth module of the terminal device in the form of a low-power Bluetooth data packet, and the terminal device reads the data through the serial port.

[0054] The terminal device in the embodiment of the present invention is a PC, and the pressure measurement value is corrected using a support vector regression model pre-trained in MATLAB, that is, the surface pressure of the soft silicone is estimated by temperature, atmospheric pressure and air pressure in the cavity, and finally the calculation results are visualized, and a pressure distribution heat map is displayed in real time on the computer screen.

[0055] It can be seen that the present invention has the function of monitoring the distribution of body surface pressure, converts the surface pressure into the air pressure in a closed cavity for measurement through soft silicone, and can send real-time pressure data to the terminal device to realize the visualization of pressure distribution, so that the monitoring personnel can more accurately assess the risk level of pressure injury of the patient.

[0056] The above-described embodiment is only a preferred solution of the present invention, but it is not intended to limit the present invention. A person skilled in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims

1. A body surface pressure monitoring device based on a flexible patch, characterized in that: It includes a pressure sensor array, a main control module, a Bluetooth module, a power management module and an air pressure sensor; The main control module controls the multiplexing chip through the communication interface and receives the digital signals from the pressure sensor and the air pressure sensor, and transmits them to the Bluetooth module through the serial port after processing; The Bluetooth module transmits data to the terminal device in the form of low-power Bluetooth data packets; The power management module is used to supply power to the pressure sensor array, the main control module and the Bluetooth module; The pressure sensor array is used to monitor the pressure distribution on the surface of human skin; The air pressure sensor is used to measure the atmospheric pressure; Each pressure sensor in the pressure sensor array is arranged on an independent flexible substrate layer, the main control module, Bluetooth module, power management module and air pressure sensor are arranged on a printed circuit board and serve as a control board, and each pressure sensor and the pressure sensor and the control board are connected by a retractable and bendable flexible serpentine wire.

2. A body surface pressure monitoring device based on a flexible patch according to claim 1, characterized in that: The interface between the pressure sensor array and the control board is a gold finger.

3. A body surface pressure monitoring device based on a flexible patch according to claim 1, characterized in that: The Bluetooth module includes a low-power Bluetooth system-on-chip chip and its peripheral circuits and a Bluetooth antenna. The low-power Bluetooth system-on-chip chip integrates a microcontroller, a serial interface and a Bluetooth radio frequency transceiver; the Bluetooth module is used to receive data from the main control module and then transmit it to the terminal device through low-power Bluetooth technology.

4. A body surface pressure monitoring device based on a flexible patch according to claim 1, characterized in that: The main control module includes a microcontroller and a multiplexing chip. The microcontroller selects a channel of the multiplexing chip and communicates with a sensor on a corresponding channel bus, and sends data to a Bluetooth module after processing. The communication method between the multiplexing chip, the pressure sensor and the microprocessor is I2C.

5. A body surface pressure monitoring device based on a flexible patch according to claim 1, characterized in that: The pressure sensor array is a 4×4 array based on an island bridge structure design, and each measuring unit includes a digital pressure sensor and a hemispherical soft silicone shell; the pressure sensors are distributed on the upper surface of the flexible base layer, and a soft silicone shell is provided on the outside to form a closed cavity, and the soft silicone shell is adhered and fixed to the upper surface of the flexible base layer; when the hemispherical outer surface of the soft silicone contacts the skin, it deforms when under pressure, causing the air pressure in the closed cavity to change; the surface pressure of the soft silicone is obtained by taking the difference between the cavity air pressure value measured by the pressure sensor and the atmospheric pressure measured by the air pressure sensor.

6. A body surface pressure monitoring device based on a flexible patch according to claim 1, characterized in that: The power management module includes a lithium battery and a DC-DC low-voltage difference linear voltage regulator circuit. The lithium battery is adhered to the back of the control board; the DC-DC low-voltage difference linear voltage regulator circuit converts the battery voltage into a DC power supply voltage to power the main control module, and powers the Bluetooth module and the pressure sensor array through the main control module.

7. A body surface pressure monitoring device based on a flexible patch according to claim 1, characterized in that: The air pressure sensor communicates directly with the microcontroller of the main control module via an I2C interface.

8. The body surface pressure monitoring device based on a flexible patch according to claim 1, characterized in that: The overall structure and circuit routing of the serpentine conductor both adopt a serpentine design of a semicircular arc plus a straight line.

9. The body surface pressure monitoring device based on a flexible patch according to claim 1, characterized in that: The flexible patch formed by the pressure sensor array adopts a double-layer board structure; the electrical components and wiring are distributed on the upper surface of the base layer, and the wiring is distributed on the lower surface, and the two surfaces are electrically connected in the form of vias.

10. The body surface pressure monitoring device based on a flexible patch according to claim 1, characterized in that: The material of the base layer is flexible polyimide.

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