Patient body position monitoring method and system and medium

Abstract

The invention relates to a patient body position monitoring method and system and a medium. The method comprises the steps that a UWB positioning base station and a UWB positioning tag are installed; the UWB positioning label sends an ultra wide band signal in a fixed time slot, and each UWB positioning base station intercepts the signal and then obtains a time difference of receiving the signal; transmitting the time difference to a data concentrator in a wireless mode through a LoRa technology; the data concentrator transmits the data to the positioning server through the Ethernet; the positioning server calls an optimized TDOA positioning algorithm to accurately position the UWB positioning tag; and angle information between the UWB positioning tags is calculated according to the positioning coordinates of the UWB positioning tags. The limitation that the body position of a patient is indirectly known through the angle of a sickbed can be avoided, and direct and accurate monitoring of the body position is achieved.

Description

Technical Field

[0001] The present invention relates to the field of medical information technology, and in particular to a patient position monitoring method, system and medium. Background Art

[0002] The supine position refers to the posture that patients take when they rest and adapt to medical care needs. In clinical practice, the corresponding position is often adjusted according to the patient's condition and treatment needs. For example, in order to prevent VAP, the head of the bed of patients with endotracheal intubation should be raised by 30° to 45°. At present, a homemade measuring table is often used in clinical practice to measure the angle of the head of the bed and adjust the patient's supine angle. This method has the following limitations: ① When the patient's compliance is poor, there is a deviation between the angle of the head of the bed and the patient's supine angle, making it difficult to accurately measure the patient's position; ② Patients with IABP inserted through the femoral artery require the head of the bed to be raised no more than 45° and the lower limbs cannot be bent. The current method can only measure the position angle of the patient's upper body, making it difficult to manage the placement of the lower limbs; ③ When the lower limbs are covered by a quilt, it is difficult to meet the nursing requirements of direct observation at any time. Summary of the invention

[0003] The object of the present invention is to provide a patient position monitoring method, system and medium to accurately measure the patient's position.

[0004] To achieve the above objectives, in a first aspect, an embodiment of the present application provides a patient position monitoring method, comprising the following specific steps:

[0005] Install UWB positioning base stations and UWB positioning tags;

[0006] The UWB positioning tag sends an ultra-wideband signal in a fixed time slot, and each UWB positioning base station intercepts the signal and obtains the time difference of the received signal;

[0007] The time difference is wirelessly transmitted to the data concentrator via LoRa technology;

[0008] The data is transmitted from the data concentrator to the positioning server via Ethernet;

[0009] The positioning server uses the optimized TDOA positioning algorithm to accurately locate the UWB positioning tag;

[0010] According to the positioning coordinates of the UWB positioning tags, the angle information between the UWB positioning tags is calculated.

[0011] The UWB positioning base station is fixed at the four corners of the bed and is used to receive and measure the pulse signals of the UWB positioning tags to obtain high-precision positioning data of the UWB positioning tags. The UWB positioning tags located between the fourth and fifth ribs of the patient's mid-axillary line are tag one, the ones on the outside of the ipsilateral hip joint are tag two, and the ones on the outside of the ipsilateral knee joint are tag three, which send UWB positioning pulse signals.

[0012] The positioning server calls the optimized TDOA positioning algorithm to accurately position the UWB positioning tag, specifically,

[0013] Two UWB positioning base stations simultaneously receive signals from the same UWB positioning tag;

[0014] The time difference between the UWB positioning base station i and the UWB positioning base station j receiving the signal means that the distance difference between the UWB positioning tag and the two base stations is a known constant c·△t ij , which defines a hyperplane, and the UWB positioning tag must be located on this hyperplane;

[0015] Multiple hyperplane intersections: If there are N UWB positioning base stations, N-1 time differences can be obtained, and then N-1 hyperplanes can be defined. The position of the UWB positioning tag is the intersection of these hyperplanes.

[0016] In three-dimensional space, the time difference between each pair of positioning base stations defines a hyperplane, and the position (x, y, z) of the UWB positioning tag can be obtained by solving the following set of equations:

[0017]

[0018] Among them, (x i ,y i ,z i ) and (x j ,y j ,z j ) are the receiver R i and R j The position of the signal, c is the propagation speed of the signal in the medium.

[0019] The patient position angle calculation method: a known non-zero vector Coordinates Non-zero vector Coordinates vector With vector The angle between them is θ, then

[0020]

[0021] In a second aspect, an embodiment of the present application is a patient position monitoring system, comprising a perception layer, an acquisition layer, a data layer and an application layer, wherein the perception layer comprises a UWB positioning base station and a UWB positioning tag, wherein the UWB positioning base station is fixed at the four corners of the bed, and is used to receive and measure the pulse signal of the UWB positioning tag to obtain high-precision positioning data of the UWB positioning tag, wherein the UWB positioning tag located between the fourth and fifth ribs of the patient's mid-axillary line is tag one, the one located on the outside of the ipsilateral hip joint is tag two, and the one located on the outside of the ipsilateral knee joint is tag three, and sends a UWB positioning pulse signal, wherein the acquisition layer is composed of a data concentrator, and wireless communication technology is used between the UWB positioning base station and the concentrator to realize wireless transmission of positioning data, wherein the data layer comprises a positioning server, and the positioning server receives the measurement data of the UWB positioning base station and completes high-precision position calculation, and the TCP / IP network communication protocol is used to exchange data between the data concentrator and the positioning server, and the application layer is a user operation terminal, which is used to set the target range of the position angle, display the angle of the patient's position, and realize the out-of-range alarm function.

[0022] In a third aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores program code, and when the program code is executed by a processor, the steps of the patient position monitoring method as described above are implemented.

[0023] The beneficial effects of adopting the above embodiment are: 1. avoiding the limitation of indirectly understanding the patient's body position through the angle of the bed, and realizing direct and accurate monitoring of the body position; 2. not being restricted by obstructions such as quilts, the patient's body position can be directly observed through the computer interface; 3. realizing unified interface management of the body position of patients in the ward. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 A flow chart of the method provided in the embodiment of the present application;

[0026] Figure 2 A system diagram provided for an embodiment of the present application;

[0027] Figure 3 A schematic diagram of specific label coordinates provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0029] It should be noted that the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0030] See also Figure 1 The present application relates to a patient position monitoring method based on ultra-wideband (UWB) wireless communication technology, comprising the following specific steps:

[0031] Install UWB positioning base stations and UWB positioning tags;

[0032] The UWB positioning tag sends an ultra-wideband signal in a fixed time slot, and each UWB positioning base station intercepts the signal and obtains the time difference of the received signal;

[0033] The time difference is wirelessly transmitted to the data concentrator via LoRa technology;

[0034] The data is transmitted from the data concentrator to the positioning server via Ethernet;

[0035] The positioning server uses the optimized TDOA positioning algorithm to accurately locate the UWB positioning tag;

[0036] According to the positioning coordinates of the UWB positioning tags, the angle information between the UWB positioning tags is calculated.

[0037] The positioning algorithm based on the time difference of arrival (TDOA) is a positioning method that uses time difference. By measuring the time it takes for the signal to arrive at the monitoring station, the distance of the signal source can be determined. The position of the signal can be determined by using the distance from the signal source to each monitoring station (using the monitoring station as the center and the distance as the radius to draw a circle). However, absolute time is generally difficult to measure. By comparing the absolute time difference of the signal arriving at each monitoring station, a hyperbola with the monitoring station as the focus and the distance difference as the major axis can be drawn. The intersection of the hyperbola is the position of the signal.

[0038] The specific steps are as follows:

[0039] ① Two positioning base stations simultaneously receive signals from the same positioning tag

[0040] ② The time difference between the signals received by positioning base station i and positioning base station j means that the distance difference between the positioning tag and the two base stations is a known constant c·△t ij , which defines a hyperplane on which the localization label must lie.

[0041] ③Multiple hyperplane intersections: If there are N positioning base stations, N-1 time differences can be obtained, and then N-1 hyperplanes can be defined. The position of the positioning tag is the intersection of these hyperplanes.

[0042] ④ In three-dimensional space, the time difference between each pair of positioning base stations defines a hyperplane. The position (x, y, z) of the positioning tag can be obtained by solving the following set of equations:

[0043] c·△t ij =[√(xx j ) 2 +(yy j ) 2 +(zz j ) 2 ]-[√(xx i ) 2 +(yy i ) 2 +(zz i )2]

[0044] Among them, (x i ,y i ,z i ) and (x j ,y j ,z j ) are the receiver R i and R j The position of the signal, c is the propagation speed of the signal in the medium, and the speed of light c≈3*108 m / s is usually used.

[0045] UWB technology transmits a large amount of data in a very short time through extremely short pulse signals. This technology does not require the use of traditional sinusoidal carriers, but instead uses nanosecond-level non-sinusoidal narrow pulses for data transmission, so its frequency band is very wide, usually above 1GHz. This technology can be used to locate UWB tags and achieve high-precision positioning at the centimeter level. Based on the high-precision position information of the three tags as raw data, the angle value between the three tags can be calculated.

[0046] Patient position angle calculation method: known non-zero vector Coordinates Non-zero vector Coordinates vector With vector The angle between them is θ, then

[0047]

[0048] like Figure 2 As shown, a patient position monitoring system includes a sensing layer 1, a collection layer 2, a data layer 3 and an application layer 4, wherein the sensing layer 1 includes a UWB positioning base station and a UWB positioning tag, wherein the UWB positioning base station is fixed at the four corners of the bed and is used to receive and measure the pulse signal of the UWB positioning tag to obtain high-precision positioning data of the UWB positioning tag, wherein the UWB positioning tag is located at three points, namely, the fourth and fifth intercostal spaces of the patient's mid-axillary line, the lateral side of the ipsilateral hip joint, and the lateral side of the ipsilateral knee joint, and sends a UWB positioning pulse signal, wherein the collection layer 2 is composed of a data concentrator, wherein the UWB positioning base station and the concentrator use wireless communication technology to realize wireless transmission of positioning data, wherein the data layer 3 includes a positioning server, wherein the positioning server receives the measurement data of the UWB positioning base station and completes high-precision position calculation, wherein the data concentrator and the positioning server use the TCP / IP network communication protocol for data exchange, wherein the application layer 4 is a user operation terminal and is used to realize the setting of the target range of the position angle, the angle display of the patient's position, and the alarm function of exceeding the range.

[0049] Example:

[0050] The following is combined with Figure 3 To further illustrate the present invention, it is assumed that the coordinates of base station A are (0,0,0), the coordinates of base station B are (4,0,0), the coordinates of base station C are (2,3.46,0) (ensuring that A, B, and C form a right triangle on the xy plane), and the coordinates of base station D are (1,1,3) (a point not on the plane formed by A, B, and C, used for three-dimensional positioning).

[0051] The real coordinates of tag T are (x, y, z) (unknown). Assume that tag T sends signals to four base stations at the same time, and base stations A, B, C, and D receive the signals at T1, T2, T3, and T4 respectively. And we know that the time synchronization between base stations is accurate, so we can calculate the following time difference: ΔT AB =T2-T1, ΔT AC =T3-T1, ΔT AD =T4-T1 (ΔT can also be calculated BC , ΔT BD , ΔT CD etc., but usually not all combinations are needed, as three base station pairs are sufficient to determine a 2D position, with the fourth base station used for 3D positioning)

[0052] Calculate the distance difference: Using the propagation speed of electromagnetic waves in the air (close to the speed of light c), we can calculate the distance difference between each pair of base stations and tags. For example: Δd AB =c*ΔT AB , Δd AC =c*ΔT AC , Δd AD =c*ΔT AD (Note: c here is the propagation speed of electromagnetic waves in the air, which is a constant. The specific value can be selected according to actual conditions, such as the approximate value of the speed of light 3×10^8m / s)

[0053] Establishing a hyperbolic equation: For each pair of base stations, we can establish a hyperbolic equation based on the distance difference. Taking base stations A and B as an example, on a two-dimensional plane, the hyperbolic equation is: √((x-0) 2 +z 2 +(y-0) 2 )=Δd AB / c. But since we are in three-dimensional space, we directly consider the three-dimensional hyperbola (actually closer to a hyperbola, but it can be approximated as a hyperbola at close distances) equation. However, in order to simplify the calculation, we usually use multiple equations formed by combining multiple base stations to solve. For three-dimensional positioning, the method we more often use is: through the distance difference between three base stations and the tag, three sets of hyperbola (or hyperbolic surface) equations are formed, plus a direct distance equation between the base station and the tag (if available), or a hyperbola equation is formed through the distance difference between the fourth base station and the tag. But here, in order to explain the application of TDOA in three-dimensional positioning, we still use distance differences to form equations. In fact, in three-dimensional space, we are more likely to use numerical methods to solve these equations, because directly solving the three-dimensional hyperbolic equation system may be very complicated.

[0054] Solve the system of equations: Now we have at least three (four in this example, but three is usually enough) equations related to the label position, forming a nonlinear system of equations with three unknowns (x, y, z). Through numerical methods (such as iteration, least squares method, etc.), we can solve this system of equations and obtain the three-dimensional coordinates (x, y, z) of the label T.

[0055] If the coordinates of label T1 are (0, 0, 0), the coordinates of label T2 are (100, 0, 0), and the coordinates of label T3 are (100, 100, 0), label T1 points to the non-zero vector →a=(100, 0, 0) of label T2, and label T2 points to the non-zero vector b→=(0, 100, 0) of label T3, then the angle between vector →a and vector b→ is θ, then cosθ=0, then θ=90°, that is, the angle of the patient's lying position is 90°.

[0056] An embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores program codes, and when the program codes are executed by a processor, the steps of the patient position monitoring method as described above are implemented.

[0057] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0058] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0059] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0060] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0061] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0062] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0063] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0064] Those skilled in the art may implement the present invention in a variety of variations without departing from the scope and essence of the present invention, such as using a feature of one embodiment to obtain another embodiment. Any modification, equivalent substitution and improvement made within the technical concept of the present invention shall be within the scope of the present invention.

Claims

1. A method for monitoring patient position, characterized in that: The specific steps include: Install UWB positioning base stations and UWB positioning tags; The UWB positioning tag sends an ultra-wideband signal in a fixed time slot, and each UWB positioning base station intercepts the signal and obtains the time difference of the received signal; The time difference is wirelessly transmitted to the data concentrator via LoRa technology; The data is transmitted from the data concentrator to the positioning server via Ethernet; The positioning server uses the optimized TDOA positioning algorithm to accurately locate the UWB positioning tag; According to the positioning coordinates of the UWB positioning tags, the angle information between the UWB positioning tags is calculated.

2. A patient position monitoring method according to claim 1, characterized in that: The UWB positioning base station is fixed at the four corners of the bed and is used to receive and measure the pulse signals of the UWB positioning tags to obtain high-precision positioning data of the UWB positioning tags. The UWB positioning tags located between the fourth and fifth ribs of the patient's mid-axillary line are tag one, the ones on the outside of the ipsilateral hip joint are tag two, and the ones on the outside of the ipsilateral knee joint are tag three, which send UWB positioning pulse signals.

3. A patient position monitoring method according to claim 1, characterized in that: The positioning server calls the optimized TDOA positioning algorithm to accurately position the UWB positioning tag, specifically, Two UWB positioning base stations simultaneously receive signals from the same UWB positioning tag; The time difference between the UWB positioning base station i and the UWB positioning base station j receiving the signal means that the distance difference between the UWB positioning tag and the two base stations is a known constant c·△t ij , which defines a hyperplane, and the UWB positioning tag must be located on this hyperplane; Multiple hyperplane intersections: If there are N UWB positioning base stations, N-1 time differences can be obtained, and then N-1 hyperplanes can be defined. The position of the UWB positioning tag is the intersection of these hyperplanes. In three-dimensional space, the time difference between each pair of positioning base stations defines a hyperplane, and the position (x, y, z) of the UWB positioning tag can be obtained by solving the following set of equations: Among them, (x i ,y i ,z i ) and (x j ,y j ,z j ) are the receiver R i and R j The position of the signal, c is the propagation speed of the signal in the medium.

4. A patient position monitoring method according to claim 3, characterized in that: The patient position angle calculation method is: the positions of the three tags are known, tag one points to tag two, and there is a non-zero vector Its coordinates Label 2 points to label 3, and there is a non-zero vector Its coordinates vector With vector The angle between them is θ, then 5. A patient position monitoring system, characterized in that: It includes a perception layer, a collection layer, a data layer and an application layer. The perception layer includes a UWB positioning base station and a UWB positioning tag. The UWB positioning base station is fixed at the four corners of the bed and is used to receive and measure the pulse signal of the UWB positioning tag to obtain high-precision positioning data of the UWB positioning tag. The UWB positioning tag located between the fourth and fifth ribs of the patient's mid-axillary line is tag one, the outer side of the ipsilateral hip joint is tag two, and the outer side of the ipsilateral knee joint is tag three, which send UWB positioning pulse signals. The collection layer is composed of a data concentrator. Wireless communication technology is used between the UWB positioning base station and the concentrator to realize wireless transmission of positioning data. The data layer includes a positioning server. The positioning server receives the measurement data of the UWB positioning base station and completes high-precision position calculation. The data concentrator and the positioning server use TCP / IP network communication protocol for data exchange. The application layer is a user operation terminal, which is used to set the target range of body angle, display the angle of the patient's body position, and realize the alarm function of exceeding the range.

6. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores program codes, and when the program codes are executed by a processor, the steps of the patient position monitoring method according to any one of claims 1 to 4 are implemented.

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