GPS intelligent tracker based on Bluetooth

Abstract

The invention discloses a GPS intelligent tracker based on Bluetooth. The GPS intelligent tracker comprises a bracelet body, a GPS module, a Bluetooth module, a communication module, a power supply module and a local terminal device. A mounting groove is formed in the bracelet body; the GPS module is arranged in the mounting groove, and the GPS module is used for obtaining GPS positioning data of the bracelet body; the Bluetooth module is arranged in the mounting groove, and the Bluetooth module is used for sending a Bluetooth signal; the communication module is arranged in the mounting groove and is in signal connection with the GPS module, and the communication module is used for sending GPS positioning data; the power supply module is arranged in the mounting groove and electrically connected with the GPS module, the Bluetooth module and the communication module, and the power supply module is used for supplying power to the GPS module, the Bluetooth module and the communication module; the local terminal device is used for receiving GPS positioning data and Bluetooth signals. The device can be worn on the body of a patient, can accurately position the position of the patient, and can be quickly found when the old or psychiatric patient gets lost or gets lost from a hospital.

Description

Technical Field

[0001] The present invention relates to the technical field of medical auxiliary equipment, and in particular to a Bluetooth-based GPS intelligent tracker. Background Art

[0002] Patient safety is paramount in the medical field. Particularly in psychiatric or geriatric wards, patients may become lost within or outside the hospital due to cognitive impairment or other reasons, posing challenges to hospital management and patient safety. Existing patient tracking wristbands can provide a certain degree of location monitoring, but their single signal source makes them susceptible to interference from building shielding and other signal sources, and their positioning accuracy needs to be improved. Therefore, developing a new tracking device that overcomes these issues in existing technologies is a research area for those skilled in the art. Summary of the Invention

[0003] The purpose of the present invention is to provide a Bluetooth-based GPS smart tracker that can be worn on a patient and accurately locate the patient's position, so that elderly or psychiatric patients can be quickly found when they get lost or stray from the hospital.

[0004] The present invention discloses a Bluetooth-based GPS intelligent tracker, which includes:

[0005] A wristband body, wherein the wristband body is provided with a mounting groove;

[0006] A GPS module is disposed in the mounting slot and is used to obtain GPS positioning data of the wristband body;

[0007] A Bluetooth module, the Bluetooth module is disposed in the mounting slot and is used to send Bluetooth signals;

[0008] a communication module, the communication module being disposed in the mounting slot and signal-connected to the GPS module, the communication module being used to send the GPS positioning data;

[0009] a power supply module, the power supply module being disposed in the mounting slot and electrically connected to the GPS module, the Bluetooth module, and the communication module, respectively, and being used to supply power to the GPS module, the Bluetooth module, and the communication module;

[0010] A local terminal device is used to receive the GPS positioning data and the Bluetooth signal.

[0011] By adopting this technical solution: the patient wears the bracelet body, obtains the GPS positioning data of the bracelet body based on the GPS module, and obtains the Bluetooth signal representing the location information of the bracelet body based on the Bluetooth module; the local terminal combines the GPS positioning data and the Bluetooth signal to accurately locate the patient wearing the bracelet body, thereby quickly finding the elderly or psychiatric patients when they get lost or lost in the hospital.

[0012] Preferably, it also includes: an alarm module, which is arranged in the installation slot, and the alarm module is used to sound an alarm when an alarm signal is received; the communication module is signal-connected to the alarm module, and the communication module is also used to receive the alarm signal and output it to the alarm module; the power supply module is electrically connected to the alarm module, and the power supply module is also used to supply power to the alarm module; the local terminal device is also used to output the alarm signal.

[0013] By adopting this technical solution, the local terminal accurately locates the patient wearing the wristband by combining GPS positioning data and the Bluetooth signal. When medical staff detect through the local terminal that a mentally ill patient wearing the wristband is about to leave the hospital, they can control the local terminal device to output an alarm signal. The communication module receives the alarm signal and outputs it to the alarm module, which activates an alarm and summons nearby staff to implement movement restrictions on the mentally ill patient wearing the wristband who is about to leave the hospital.

[0014] Preferably, it also includes: a detection module, which is arranged in the installation slot and is used to obtain a detection signal; the communication module is signal-connected to the detection module, and the communication module is also used to send the detection signal; the power supply module is electrically connected to the detection module, and the power supply module is also used to supply power to the detection module; the local terminal device is also used to receive the detection signal.

[0015] By adopting this technical solution: during the daily wearing of the bracelet body, data on human body parameters can also be collected through the detection module, and the detection signal containing the human body parameter data is output to the local terminal device through the communication module, thereby realizing the recording and storage of the patient's daily body parameters.

[0016] Preferably, the detection module includes a heart rate detection unit and / or a body temperature detection unit.

[0017] Preferably, it also includes: a lighting module, which is arranged in the mounting groove; the power supply module is electrically connected to the lighting module, and the power supply module is also used to supply power to the lighting module; a control switch, which is installed on the bracelet body and electrically connected to the lighting module, and the control switch is used to control the on / off of the lighting module.

[0018] By adopting this technical solution: when elderly patients wear the bracelet body, they can also start the lighting module by controlling the switch at night to achieve lighting when going to the toilet at night.

[0019] Preferably, the system further comprises: a PCB board, wherein the PCB board is arranged in the mounting slot, and the GPS module, the Bluetooth module, the communication module, the power supply module, the alarm module, the lighting module and the detection module are integrally mounted on the PCB board;

[0020] A waterproof and dustproof cover is installed on the installation groove and covers the surface of the PCB board.

[0021] By adopting this technical solution: the PCB board is used to realize the integrated installation of functional modules such as GPS module, Bluetooth module, communication module, power supply module, alarm module, lighting module, and detection module, which reduces the design size of the installation slot. The waterproof and dustproof cover provides waterproof and dustproof protection for the PCB board, ensuring the stable use of various functional modules.

[0022] Preferably, the local terminal device comprises at least three Bluetooth gateways distributed at different locations in the hospital, and a central processor connected to the at least three Bluetooth gateways and the communication module respectively by signals;

[0023] The central processing unit is used to obtain the position coordinates of the wristband body according to the positioning data and the Bluetooth signal, and is also used to output the alarm signal when the wristband body enters a preset alarm area.

[0024] More preferably, the central processing unit is configured to obtain the positioning position of the wristband body according to the following steps:

[0025] Step 100: formatting the positioning data and the Bluetooth signal, and cleaning abnormal values ​​in the positioning data and abnormal values ​​in the RSSI data of the Bluetooth signal;

[0026] Step 200: perform distance estimation based on RSSI data:

[0027] Construct a free space propagation model and express the relationship between signal strength and distance as:

[0028] RSSI = TXPower - 10nlog 10 (d)+X

[0029] Where TXPower is the transmit power of the Bluetooth communication module; n is the path loss exponent; d is the distance between the wristband body and the Bluetooth gateway; X is the additional attenuation of the ambient noise;

[0030] Substitute the RSSI data in the Bluetooth signal into the free space propagation model to solve the distance value between the wristband body and each Bluetooth gateway;

[0031] Step 300, estimating the RSSI positioning result of the wristband body through a three-point positioning algorithm;

[0032] Step 400: The RSSI positioning result of the wristband body and the GPS positioning data are integrated based on the Kalman filter algorithm to obtain the position coordinates of the wristband body.

[0033] Compared with the prior art, the present invention has the following technical advantages:

[0034] Firstly, the present invention can be worn on a patient and accurately locate the patient's position, enabling monitoring and rapid retrieval of elderly or psychiatric patients after they get lost or stray from a hospital.

[0035] Secondly, the present invention can activate an active alarm when a patient is about to go missing, so that staff can restrict mentally ill patients from leaving the hospital.

[0036] Third, the present invention can provide a lighting function to help elderly patients wear the bracelet body to achieve lighting when going to the toilet at night.

[0037] Fourthly, the present invention can collect and record data on human body parameters during daily wear.

[0038] Finally, the hardware part of the present invention has a simple structure and is easy to prepare and implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a status diagram of the patient, Bluetooth gateway, and central processor during the use of this solution.

[0040] Figure 2 This is a structural diagram of the wristband body in Example 1.

[0041] Figure 3 for Figure 2 Schematic diagram of the structure after removing the PCB board and the rear waterproof and dustproof cover.

[0042] Figure 4 This is a schematic diagram of the signal connections of the various functional modules on the PCB board in Example 1.

[0043] Figure 5 This is a schematic diagram of the signal connections of the various functional modules on the PCB board in Example 2.

[0044] Figure 6 Schematic diagram of signal connections of various functional modules on the PCB board in Example 3.

[0045] In the figure, the corresponding reference numerals of the various components are as follows:

[0046] 100, wristband body; 210, Bluetooth gateway; 220, CPU; 110, mounting slot; 120, PCB board; 130, waterproof and dustproof cover; 140, control switch; 310, GPS module; 320, Bluetooth module; 330, communication module; 340, lighting module; 350, power supply module; 360, alarm module; 370, detection module. DETAILED DESCRIPTION

[0047] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0048] Example 1, please refer to Figure 1-4 :

[0049] A Bluetooth-based GPS smart tracker includes a wristband body 100 and a local terminal device.

[0050] The wristband body 100 is designed to be worn on the wrist of a geriatric or psychiatric patient. A control switch 140 is provided on one side of the wristband body 100. A mounting slot 110 is provided on the wristband body 100. A PCB board 120 and a waterproof and dustproof cover 130 are mounted in the mounting slot 110. The waterproof and dustproof cover 130 covers the surface of the PCB board 120 and protects the PCB board 120 from water and dust during daily use.

[0051] The PCB board 120 is integrated with a GPS module 310, a Bluetooth module 320, a communication module 330, a lighting module 340 and a power supply module 350. The lighting module 340 uses lighting beads to achieve lighting when it is turned on. The control switch 140 is electrically connected to the lighting module 340 and is used to control the lighting module 340 to start / stop. The GPS module 310 is used to obtain the GPS positioning data of the bracelet body 100; the Bluetooth module 320 is used to send Bluetooth signals to the outside in real time; the communication module 330 is signal-connected to the GPS module 310 and is used to output the GPS positioning data to the outside; the power supply module 350 uses a lithium battery and is used to power the GPS module 310, the Bluetooth module 320, the lighting module 340 and the communication module 330 respectively.

[0052] The local terminal device includes at least three Bluetooth gateways 210 and a central processor 220. The at least three Bluetooth gateways 210 are configured to be installed at different locations within the hospital to maximize coverage of the entire hospital area while ensuring that communication between the Bluetooth gateways 210 is not affected. The central processor 220 is signal-connected to each of the at least three Bluetooth gateways 210 to obtain Bluetooth signals. The central processor 220 is further signal-connected to the communication module 330 to obtain GPS positioning data output by the communication module 330.

[0053] The central processor 220 is provided with a positioning operation module, which is used to integrate the received GPS positioning and Bluetooth signals to obtain accurate positioning of the patient's location. Specifically,

[0054] The local terminal device is configured to implement the fusion positioning by performing the following working process:

[0055] Each Bluetooth gateway 210 receives the Bluetooth signal output by the Bluetooth module 320 on the GPS smart tracker within its coverage area, records the RSSI value of the Bluetooth signal, attaches a timestamp and identification information to form RSSI signal data, and sends the RSSI signal data to the central processor 220.

[0056] The central processor 220 formats the collected RSSI signal data and GPS positioning data: clears abnormal values ​​in the RSSI signal data caused by multipath effects or signal interference, and cleans abnormal values ​​in the GPS positioning data caused by signal loss or incorrect positioning due to occlusion or reflection.

[0057] Then, the median filtering method is used to process the RSSI signal data and GPS positioning data respectively to reduce noise and outliers and improve data quality:

[0058] Apply median filtering to the RSSI signal data. Window selection: For each RSSI data point, select a window containing an odd number of data points (for example, a 5-point window containing the current point and two points before and after it). Median calculation: Calculate the median value for each RSSI value within the window. The median value is the value in the middle after sorting the data from small to large. Replacement operation: Replace the original RSSI value in the center of the window with the calculated median value. The formula is expressed as:

[0059] RSSI filtered (t) = median(RSSI (t-k) ,...,RSSI (t) ,...,RSSI (t+k) )

[0060] Among them, RSSI filtered (t) is the filtered RSSI value, t is the index of the center data point, and k is the window radius.

[0061] Apply median filtering to GPS positioning data. Noise identification: Since GPS positioning data is usually relatively stable, first identify possible noise or erroneous data points. Apply median filtering: Similar to RSSI, apply median filtering to GPS positioning data to smooth out short-term fluctuations. The median filter formula for GPS coordinates is:

[0062] GPS filtered (t)=median(GPS (t-k) ,...,GPS (t) ,...,GPS (t+k) )

[0063] GPS filtered (t) is the GPS coordinate value after filtering.

[0064] The filtering results are checked for smoothness and boundary effects are processed to ensure that the filtered data is smooth and there are no new abnormal fluctuations.

[0065] RSSI ranging: According to the free space propagation model, the relationship between signal strength and distance can be expressed as:

[0066] RSSI = TXPower - 10nlog 10 (d)+X

[0067] in:

[0068] TXPower is the transmit power of the tracking device (dBm).

[0069] n is the path loss exponent that depends on the environment (usually between 1.6 and 2.5).

[0070] d is the distance between the beacon and the receiver (in meters).

[0071] X is the additional attenuation caused by environmental noise and other random factors.

[0072] Using the filtered RSSI value, the distance between the device and the Bluetooth beacon is calculated according to the above model. First, the values ​​of TXPower and n need to be known or estimated. TXPower is generally known, while the path loss index n varies in different propagation environments. Generally speaking, the value of n ranges from 2 to 6, and this invention will be debugged according to the deployment environment. Then, the RSSI value is substituted into the model to solve for the distance d.

[0073]

[0074] Position estimation: Estimate the device's indoor coordinates using a three-point positioning algorithm. The locations of at least three Bluetooth gateways 210 are predetermined and known, denoted as G1(x1, y1), G2(x2, y2), and G3(x3, y3). The distances between the tracker and each Bluetooth gateway are calculated according to step 3 and are denoted as d1, d2, and d3, respectively.

[0075] For each Bluetooth gateway, the following set of equations is established based on the distance estimation:

[0076]

[0077] Where (x, y) is the position coordinate of the tracker, and the above equation is solved to obtain the estimated position.

[0078] Position optimization: Indoor RSSI positioning results are fused with outdoor GPS positioning results through the Kalman filter algorithm to reduce errors and improve positioning accuracy and robustness.

[0079] In this scheme, it is assumed that the patient cannot move quickly, and the speed factor is not considered to simplify the calculation.

[0080] Define the state vector

[0081]

[0082] Among them, x k and y k are the position coordinates of the smart tracker in two-dimensional space at time k.

[0083] Initialize the state vector X0 and the state covariance matrix P0.

[0084] State Prediction: The position prediction remains unchanged without considering the velocity, as we assume that the position changes are negligible over short time intervals:

[0085] Covariance prediction: Predict the state covariance matrix at the next moment. Here, only the uncertainty of the position is considered. Usually, since the system noise is very small, it can be assumed to be the unit matrix: Among them, Q k-1 is the covariance matrix of the process noise, which is usually assumed to be small.

[0086] Measurement model: For GPS, the measurement model directly gives the location information and can be expressed as:

[0087] Z GPS,k =H GPS,k x k +V GPS,k

[0088] Among them H GPS,k is an identity matrix or a matrix containing only position information, V GPS,k is the noise of GPS measurement.

[0089] For RSSI, the measurement vector Z RSSI,k Contains distance information from each beacon, which needs to be converted into location information:

[0090] Z RSSI,k =H RSSI,k x k +V RSSI,k

[0091] Among them H RSSI,k is the Jacobian matrix of the function that converts position to distance, V RSSI,k is the noise of the RSSI measurement.

[0092] Fusion Model:

[0093] In this scheme, GPS and RSSI are used simultaneously, and the two are integrated into a unified measurement vector, and a weight is assigned to each measurement. This can be achieved by weighting the observation model matrix H K and the weighted measurement noise covariance matrix R K To achieve:

[0094]

[0095] Where α is the weight of RSSI relative to GPS, and are the noise variances of GPS and RSSI measurements, respectively.

[0096] Compute the residuals using the fused measurement model:

[0097]

[0098] Taking into account the weighted observation model and measurement noise, calculate the Kalman gain:

[0099]

[0100] Update the state estimate based on the measurement results:

[0101]

[0102] Update the state covariance matrix:

[0103]

[0104] The above prediction and update steps are repeated until the estimation of all time steps is completed.

[0105] Output the final state estimate As a positioning result.

[0106] Example 2, please refer to Figure 5 :

[0107] Compared with Example 1, Example 2 further includes: an alarm module 360 ​​.

[0108] The alarm module 360 ​​is integrated with the PCB 120 and is configured to generate an alarm upon receiving an alarm signal. The central processor 220 in the local terminal device also includes an alarm instruction unit configured to output the alarm signal. The communication module 330 is signal-connected to the alarm module 360 ​​and configured to receive and output the alarm signal to the alarm module 360. The power supply module 350 is electrically connected to the alarm module 360 ​​and is configured to supply power to the alarm module 360.

[0109] When medical staff detects through the local terminal that a mentally ill patient wearing the bracelet body 100 is about to leave the hospital, they can control the central processor 220 to output an alarm signal, and the communication module 330 receives the alarm signal and outputs it to the alarm module 360. The alarm module 360 ​​executes the alarm and summons nearby staff to perform movement restraints on the mentally ill patient wearing the bracelet body 100 who is about to leave the hospital.

[0110] Example 3, please refer to Figure 6 :

[0111] Compared with Example 1, Example 3 further includes: a detection module 370 .

[0112] The detection module 370 is integrated with the PCB board 120 and is used to obtain a detection signal containing physiological parameters of the wearer when the wristband body 100 is worn. Furthermore, the detection module 370 may include a heart rate detection unit and / or a body temperature detection unit. The power supply module 350 is electrically connected to the detection module 370 and is used to supply power to the detection module 370.

[0113] The communication module 330 is signal-connected to the detection module 370 and is used to send the detection signal to the central processor 220 in the local terminal device. The central processor 220 is also provided with a data storage unit for temporarily storing the detection signal. It should be noted that in the prior art, functional modules for detecting human heart rate and body temperature have been maturely applied in smart watches such as Xiaomi. Therefore, this solution will not further elaborate on the working principles of the heart rate detection unit and / or body temperature detection unit.

[0114] On the basis of achieving the technical effects of Example 1, this solution can also collect data on human body parameters through the detection module 370 during daily wearing of the bracelet body 100. The detection signal containing the human body parameter data is output to the central processor 220 through the communication module 330, thereby realizing the recording and storage of daily body parameters of patients wearing this device.

[0115] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the scope of protection of the present invention.

Claims

1. A Bluetooth-based GPS smart tracker, characterized in that: include: A bracelet body, wherein a mounting groove is provided on the bracelet body; A GPS module, the GPS module is arranged in the installation slot, and the GPS module is used to obtain GPS positioning data of the wristband body; A Bluetooth module, the Bluetooth module is disposed in the installation slot, and the Bluetooth module is used to send a Bluetooth signal; A communication module, the communication module is arranged in the installation slot and is connected to the GPS module signal, and the communication module is used to send the GPS positioning data; A power supply module, the power supply module is arranged in the mounting groove and is electrically connected to the GPS module, the Bluetooth module and the communication module respectively, and the power supply module is used to supply power to the GPS module, the Bluetooth module and the communication module; A local terminal device is used to receive the GPS positioning data and the Bluetooth signal.

2. The GPS smart tracker according to claim 1, characterized in that: Also includes: An alarm module, the alarm module is arranged in the installation slot, and the alarm module is used to give an alarm when receiving an alarm signal; The communication module is connected to the alarm module signal, and the communication module is also used to receive the alarm signal and output it to the alarm module; The power supply module is electrically connected to the alarm module, and the power supply module is also used to supply power to the alarm module; The local terminal device is also used to output the alarm signal.

3. The GPS smart tracker according to claim 2, characterized in that: Also includes: A detection module, the detection module is disposed in the installation slot, and the detection module is used to obtain a detection signal; The communication module is connected to the detection module by signal, and the detection module is also used to send the alarm signal; The power supply module is electrically connected to the detection module, and the power supply module is also used to supply power to the detection module; The local terminal device is further configured to receive the detection signal.

4. The GPS smart tracker according to claim 3, characterized in that: The detection module includes a heart rate detection unit and / or a body temperature detection unit.

5. The GPS smart tracker according to claim 4, characterized in that: Also includes: A lighting module, wherein the lighting module is disposed in the mounting groove; The power supply module is electrically connected to the alarm module, and the power supply module is also used to supply power to the lighting module; A control switch is installed on the bracelet body and is electrically connected to the lighting module. The control switch is used to control the on / off of the lighting module.

6. The GPS smart tracker according to claim 5, characterized in that: Also includes: A PCB board, wherein the PCB board is arranged in the installation slot, and the GPS module, the Bluetooth module, the communication module, the power supply module, the alarm module, the lighting module and the detection module are integrally installed on the PCB board; A waterproof and dustproof cover is installed on the installation groove and covers the surface of the PCB board.

7. The GPS smart tracker according to claim 6, characterized in that: The local terminal device includes at least three Bluetooth gateways distributed at different locations in the hospital, and a central processor connected to the at least three Bluetooth gateways and the communication module respectively by signals; The central processor is used to obtain the position coordinates of the bracelet body according to the positioning data and the Bluetooth signal, and is also used to output the alarm signal when the bracelet body enters a preset alarm area.

8. The GPS smart tracker according to claim 7, characterized in that: The central processor is configured to obtain the positioning position of the wristband body according to the following steps: Step 100, formatting the positioning data and the Bluetooth signal, and cleaning abnormal values ​​in the positioning data and abnormal values ​​in the RSSI data in the Bluetooth signal; Step 200, perform ranging estimation based on RSSI data: Construct a free space propagation model and express the relationship between signal strength and distance as: RSSI=TXPower-10nlog 10 (d)+X Among them, TXPower is the transmission power of the Bluetooth communication module; n is the path loss index; d is the distance between the wristband body and the Bluetooth gateway; X is the additional attenuation of environmental noise; Substitute the RSSI data in the Bluetooth signal into the free space propagation model to solve the distance value between the wristband body and each Bluetooth gateway respectively; Step 300, estimating the RSSI positioning result of the wristband body through a three-point positioning algorithm; Step 400: The RSSI positioning result of the wristband body and the GPS positioning data are integrated based on the Kalman filter algorithm to obtain the position coordinates of the wristband body.

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