UWB-technology-based surgical positioning method, system and device, and medium

Abstract

Disclosed in the present invention are a UWB-technology-based surgical positioning method, system and device, and a medium. The method comprises: establishing a human body electromagnetic simulation model, and using UWB technology to provide a signal which is propagated within a human body in the human body electromagnetic simulation model, so as to establish a channel model; constructing a path loss model for calculating a path loss in the channel model; on the basis of a signal reception principle, constructing a mathematical model which includes a received power and a path loss; after a first path loss is calculated by means of the path loss model, calculating a received power on the basis of the mathematical model; at the minimum received power, calculating a second path loss on the basis of the mathematical model; calculating a communication distance on the basis of the second path loss, a free-space path loss model, and environmental parameters which include a shadow loss; and on the basis of the communication distance, using a trilateration positioning method to perform surgical positioning on a target to be measured. The present invention can improve the accuracy of surgical positioning, thereby avoiding causing additional harm to patients.

Description

A surgical positioning method, system, device and medium based on UWB technology Technical Field

[0001] The present invention relates to the field of surgical positioning technology, and in particular to a surgical positioning method, system, equipment and medium based on UWB technology. Background Art

[0002] During surgery, especially orthopedic surgery, a traditional method for accurately locating the surgical site relies on the surgeon's years of surgical experience. A positioning pin is placed on the patient, and then X-rays are taken to obtain transverse and longitudinal sections, which are then used to correct the positioning pin. This method requires extensive experience and high standards from the surgeon, thus limiting its widespread application. Furthermore, this reliance on experience to determine the surgical site carries uncertainty and risks, and any inaccurate positioning requires repetition. Patients sometimes require multiple X-rays, sometimes as many as a dozen, which exposes them to excessive radiation.

[0003] Another approach involves the use of orthopedic computer-assisted navigation technology. Based on intraoperative images, this technology employs appropriate positioning techniques to accurately track, display, and guide the surgical site and surgical instruments in real time, enabling orthopedic surgeons to perform surgery based on the navigation images. However, this navigation information is difficult to understand. Surgeons primarily use tomographic images displayed on the navigation system screen, superimposed with surgical instrument information, for intraoperative positioning. These images do not accurately reflect the patient's current position, making it difficult for surgeons to intuitively understand the spatial relationship between the surgical instruments and the patient's actual anatomical structures in a real-life surgical scenario. Furthermore, this positioning method can cause additional wounds to the patient beyond the surgical site. Therefore, the aforementioned surgical positioning methods are not highly accurate, and the difficulty in understanding the surgical positioning position can also cause additional harm to the patient.

[0004] Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a surgical positioning method, system, device and medium based on UWB technology, which can improve the accuracy of surgical positioning and avoid causing additional harm to the patient.

[0006] In a first aspect, an embodiment of the present invention provides a surgical positioning method based on UWB technology, the surgical positioning method based on UWB technology comprising:

[0007] Establishing a human electromagnetic simulation model, and using UWB technology to provide signals propagating in the human body in the human electromagnetic simulation model, and establishing a channel model;

[0008] Constructing a path loss model for calculating path loss in the channel model;

[0009] Based on the signal reception principle, a mathematical model including received power and path loss is constructed;

[0010] After calculating the first path loss using the path loss model, calculating the received power according to the mathematical model;

[0011] Under the minimum received power, calculating the second path loss according to the mathematical model;

[0012] Calculating a communication distance based on the second path loss, a free space path loss model, and environmental parameters including shadow loss;

[0013] According to the communication distance, a three-ball intersection positioning method is used to perform surgical positioning on the target to be measured.

[0014] Compared with the prior art, the first aspect of the present invention has the following beneficial effects:

[0015] This method uses UWB technology to provide signals propagating within the human body in a human electromagnetic simulation model, establishes an easily implementable channel model, and saves time and cost. The use of UWB technology for signal propagation can minimize the signal transmission power and has the advantages of strong multipath resolution, low system complexity, and high theoretical ranging accuracy. The communication distance is calculated by comprehensively considering path loss and environmental parameters including shadow loss, which can improve the accuracy of communication distance calculation. Based on the communication distance, the three-sphere intersection positioning method is used to perform surgical positioning on the target to be measured, which can improve the accuracy of surgical positioning, avoid additional harm to the patient, and ensure human safety.

[0016] According to some embodiments of the present invention, a path loss model for calculating the channel model is constructed in the following manner: loss =p0+α((d+d0) / d0) n

[0017] Among them, p loss represents the path loss, p0 represents the reference value, d represents the depth from the body surface to the body, d0 represents the reference depth, n represents the path loss exponent, and α represents a constant.

[0018] According to some embodiments of the present invention, a mathematical model including received power and path loss is constructed as follows: Prx (dBm) = Ptx (dBm) + Gtx (dBi) + Grx (dBi) - L (dB)

[0019] Where Prx (dBm) represents the received power, Ptx (dBm) represents the transmitted power, Gtx (dBi) represents the transmit antenna gain, Grx (dBi) represents the receive antenna gain, and L (dB) represents the path loss.

[0020] According to some embodiments of the present invention, calculating the communication distance based on the second path loss, the free space path loss model, and environmental parameters including shadow loss includes:

[0021] Calculating a signal loss based on the environmental parameters including the shadow loss and the second path loss;

[0022] Based on the signal loss, the communication distance is calculated using the free space path loss model; wherein the free space path loss model is: L = 32.4 + 20*log(D) + 20*log(M)

[0023] Where L represents signal loss, D represents the free space propagation distance of the wireless signal, and M represents the propagation signal frequency.

[0024] According to some embodiments of the present invention, performing surgical positioning on the target to be measured using a three-ball intersection positioning method based on the communication distance includes:

[0025] Establishing a ranging model including four transmitting devices with known spatial positions and one receiving terminal, and calculating the communication distance from each transmitting device to the receiving terminal;

[0026] According to the communication distance and the ranging model, a three-sphere intersection positioning method is used to calculate a feasible coordinate estimation set of the receiving terminal;

[0027] The feasible coordinate estimation set is plane-fitted using the least squares method to obtain the coordinate position of the receiving terminal, and surgical positioning of the target to be measured is performed based on the coordinate position.

[0028] According to some embodiments of the present invention, the calculating, based on the communication distance and the ranging model, using a three-sphere intersection positioning method to obtain a feasible coordinate estimation set of the receiving terminal includes:

[0029] Based on the three known spatial positions of the transmitting device and the receiving terminal in the ranging model, a three-sphere intersection positioning method is used to obtain two points where the three spheres intersect;

[0030] constructing a sphere using a transmitting device at a fourth known spatial position, the receiving terminal, and a communication distance between the transmitting device at the fourth known spatial position and the receiving terminal;

[0031] Calculating a quadratic equation based on the equation of the sphere and the coordinates of the two points;

[0032] Using the discriminant of the quadratic equation to determine the number of intersections between the straight line between the two points and the sphere;

[0033] If there is an intersection between the straight line between the two points and the sphere, a feasible coordinate estimation set of the receiving terminal is calculated using the solution of the quadratic equation.

[0034] According to some embodiments of the present invention, the calculating a set of feasible coordinate estimates of the receiving terminal using a solution of the quadratic equation includes:

[0035] Based on the first solution and the second solution of the quadratic equation, if the first solution and the second solution are both less than 0, selecting a point closer to the center of the sphere as a first feasible coordinate;

[0036] If the first solution is less than 0 and the second solution is greater than 1, then select the point closer to the center of the sphere as the second feasible coordinate;

[0037] If the first solution is equal to the second solution, the point tangent to the sphere is used as the third feasible coordinate;

[0038] If the first solution is greater than 0 and less than 1 and the second solution is greater than 1, the point intersecting with the sphere is used as the fourth feasible coordinate;

[0039] The first feasible coordinates, the second feasible coordinates, the third feasible coordinates, and the fourth feasible coordinates are combined to obtain a feasible coordinate estimation set.

[0040] In a second aspect, an embodiment of the present invention further provides a surgical positioning system based on UWB technology, the surgical positioning system based on UWB technology comprising:

[0041] The first model building unit is used to build a human electromagnetic simulation model, and use UWB technology to provide a signal propagating in the human body in the human electromagnetic simulation model to build a channel model;

[0042] A second model building unit is used to build a path loss model for calculating the path loss in the channel model;

[0043] The third model building unit is used to build a mathematical model including received power and path loss according to the signal reception principle;

[0044] a first data calculation unit, configured to calculate a first path loss using the path loss model and then calculate a received power according to the mathematical model;

[0045] A second data calculation unit, configured to calculate a second path loss according to the mathematical model at the minimum received power;

[0046] a third data calculation unit, configured to calculate a communication distance based on the second path loss, a free space path loss model, and environmental parameters including shadow loss;

[0047] The target positioning unit is used to perform surgical positioning on the target according to the communication distance by adopting a three-ball intersection positioning method.

[0048] In a third aspect, an embodiment of the present invention also provides a surgical positioning device based on UWB technology, comprising at least one control processor and a memory for communicating with the at least one control processor; the memory stores instructions that can be executed by the at least one control processor, and the instructions are executed by the at least one control processor so that the at least one control processor can execute a surgical positioning method based on UWB technology as described above.

[0049] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the surgical positioning method based on UWB technology as described above.

[0050] It can be understood that the beneficial effects of the above-mentioned second to fourth aspects compared with the relevant technologies are the same as the beneficial effects of the above-mentioned first aspect compared with the relevant technologies. Please refer to the relevant description in the above-mentioned first aspect and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments with reference to the following drawings, in which:

[0052] FIG1 is a flow chart of a surgical positioning method based on UWB technology according to the present invention;

[0053] FIG2 is a schematic diagram showing the positional relationship between a line segment P1P2 and a ball according to an embodiment of the present invention;

[0054] FIG3 is a structural diagram of a surgical positioning system based on UWB technology according to the present invention;

[0055] FIG4 is a schematic diagram of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0056] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0057] In the description of the present invention, if there is a description of first, second, etc., it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0058] In the description of the present invention, it should be understood that descriptions involving orientation, such as the orientation or positional relationship indicated by up, down, etc., are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0059] In the description of the present invention, it should be noted that, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0060] During surgery, especially orthopedic surgery, a traditional method for accurately locating the surgical site relies on the surgeon's years of surgical experience. A positioning pin is placed on the patient, and then X-rays are taken to obtain transverse and longitudinal sections, which are then used to correct the positioning pin. This method requires extensive experience and high standards from the surgeon, thus limiting its widespread application. Furthermore, this reliance on experience to determine the surgical site carries uncertainty and risks, and any inaccurate positioning requires repetition. Patients sometimes require multiple X-rays, sometimes as many as a dozen, which exposes them to excessive radiation.

[0061] Another approach involves the use of orthopedic computer-assisted navigation technology. Based on intraoperative images, this technology employs appropriate positioning techniques to accurately track, display, and guide the surgical site and surgical instruments in real time, enabling orthopedic surgeons to perform surgery based on the navigation images. However, this navigation information is difficult to understand. Surgeons primarily use tomographic images displayed on the navigation system screen, superimposed with surgical instrument information, for intraoperative positioning. These images do not accurately reflect the patient's current position, making it difficult for surgeons to intuitively understand the spatial relationship between the surgical instruments and the patient's actual anatomical structures in a real-life surgical scenario. Furthermore, this positioning method can cause additional wounds to the patient beyond the surgical site. Therefore, the aforementioned surgical positioning methods are not highly accurate, and the difficulty in understanding the surgical positioning position can also cause additional harm to the patient.

[0062] To solve the above problems, the present invention adopts UWB technology to provide signals propagated in the human body in a human electromagnetic simulation model, establishes an easy-to-implement channel model, saves time and cost, adopts UWB technology for signal propagation, can minimize the signal transmission power, and has the advantages of strong multipath resolution capability, low system complexity, and high theoretical ranging accuracy; comprehensively considers path loss and environmental parameters including shadow loss to calculate the communication distance, which can improve the accuracy of communication distance calculation; according to the communication distance, the three-ball intersection positioning method is used to perform surgical positioning of the target to be measured, which can improve the accuracy of surgical positioning, avoid additional harm to the patient, and ensure human safety.

[0063] 1 , an embodiment of the present invention provides a surgical positioning method based on UWB technology. The surgical positioning method based on UWB technology includes but is not limited to steps S100 to S700, wherein:

[0064] Step S100: establishing a human electromagnetic simulation model, and using UWB technology to provide signals propagating in the human body in the human electromagnetic simulation model, and establishing a channel model;

[0065] Step S200: constructing a path loss model for calculating path loss in a channel model;

[0066] Step S300: Construct a mathematical model including received power and path loss based on the signal reception principle;

[0067] Step S400: After calculating the first path loss using the path loss model, calculate the received power according to the mathematical model;

[0068] Step S500: Calculate the second path loss according to the mathematical model at the minimum received power;

[0069] Step S600: Calculate the communication distance based on the second path loss, the free space path loss model, and environmental parameters including shadow loss;

[0070] Step S700: Based on the communication distance, a three-ball intersection positioning method is used to perform surgical positioning on the target.

[0071] In this embodiment, in order to save time costs, this embodiment establishes a human electromagnetic simulation model and uses UWB technology to provide signals propagated in the human body in the human electromagnetic simulation model, thereby establishing an easy-to-implement channel model; in order to improve the accuracy of communication distance calculation, this embodiment constructs a path loss model for calculating the path loss in the channel model, and constructs a mathematical model including receiving power and path loss according to the signal reception principle. After calculating the first path loss through the path loss model, the receiving power is calculated according to the mathematical model, and at the minimum receiving power, the second path loss is calculated according to the mathematical model. Based on the second path loss, the free space path loss model and the environmental parameters including shadow loss, the communication distance is calculated; in order to improve the accuracy of surgical positioning, this embodiment uses a three-ball intersection positioning method according to the communication distance to perform surgical positioning on the target to be measured.

[0072] In some embodiments, the path loss model used to calculate the channel model is constructed as follows: loss =p0+α((d+d0) / d0) n

[0073] Among them, p loss represents the path loss, p0 represents the reference value, d represents the depth from the body surface to the body, d0 represents the reference depth, n represents the path loss exponent, and α represents a constant.

[0074] In this embodiment, since a general logarithmic function is not applicable to a channel model established based on UWB technology, the path loss model constructed in this embodiment can be applicable to a channel model established based on UWB technology.

[0075] In some embodiments, a mathematical model including received power and path loss is constructed as follows: Prx (dBm) = Ptx (dBm) + Gtx (dBi) + Grx (dBi) - L (dB)

[0076] Where Prx (dBm) represents the received power, Ptx (dBm) represents the transmitted power, Gtx (dBi) represents the transmit antenna gain, Grx (dBi) represents the receive antenna gain, and L (dB) represents the path loss.

[0077] In some embodiments, calculating the communication distance based on the second path loss, the free space path loss model, and environmental parameters including shadow loss includes:

[0078] The signal loss is calculated based on the environmental parameters including the shadow loss and the second path loss;

[0079] Based on the signal loss, the communication distance is calculated using the free space path loss model; the free space path loss model is: L = 32.4 + 20*log(D) + 20*log(M)

[0080] Where L represents signal loss in dB, D represents the free space propagation distance of the wireless signal in km, and M represents the propagation signal frequency in MHz.

[0081] In actual communication environments, satellite communications can use an ideal path loss model. However, in the actual operating room environment of this solution, obstacles such as surgical instruments and operating tables may absorb some of the signal energy. Therefore, the above formula needs to be further improved:

[0082] Where d0 represents the reference distance (i.e., reference depth), n represents the path loss exponent in different environments, L(d) represents the signal loss after partial absorption of the signal energy due to obstacles such as surgical instruments and operating tables, and d represents the depth from the body surface to the inside of the body.

[0083] In this embodiment, the communication distance is calculated by comprehensively considering the path loss and environmental parameters including shadow loss, which can improve the accuracy of the communication distance calculation.

[0084] In some embodiments, a three-ball intersection positioning method is used to perform surgical positioning on a target according to the communication distance, including:

[0085] Establish a ranging model that includes four transmitters with known spatial positions and one receiving terminal, and calculate the communication distance from each transmitter to the receiving terminal;

[0086] According to the communication distance and ranging model, the feasible coordinate estimation set of the receiving terminal is calculated using the three-sphere intersection positioning method;

[0087] The least squares method is used to perform plane fitting on the feasible coordinate estimation set to obtain the coordinate position of the receiving terminal, and the surgical positioning of the target to be measured is performed based on the coordinate position.

[0088] In this embodiment, there is no need to place a positioning needle on the patient. Only the three-ball intersection positioning method is used to perform surgical positioning on the target to be measured, which can improve the accuracy of surgical positioning, avoid additional harm to the patient, and ensure human safety.

[0089] In some embodiments, based on the communication distance and the ranging model, a three-sphere intersection positioning method is used to calculate a feasible coordinate estimation set of the receiving terminal, including:

[0090] Based on the three known spatial positions of the transmitter and the receiving terminal in the ranging model, the three-sphere intersection positioning method is used to obtain the two points where the three spheres intersect;

[0091] Constructing a sphere using a transmitter and a receiving terminal at a fourth known spatial position and a communication distance between the transmitter and the receiving terminal at the fourth known spatial position;

[0092] According to the equation of the sphere and the coordinates of the two points, a quadratic equation is calculated;

[0093] Use the discriminant of a quadratic equation to determine the number of intersections between the line between two points and the sphere;

[0094] If there is an intersection between the line between the two points and the sphere, the solution of the quadratic equation is used to calculate the set of feasible coordinate estimates of the receiving terminal.

[0095] In some embodiments, computing a set of feasible coordinate estimates for a receiving terminal using a solution of a quadratic equation includes:

[0096] Based on the first and second solutions of the quadratic equation, if both the first and second solutions are less than 0, the point closer to the center of the sphere is selected as the first feasible coordinate;

[0097] If the first solution is less than 0 and the second solution is greater than 1, the point closer to the center of the sphere is selected as the second feasible coordinate;

[0098] If the first solution is equal to the second solution, the point tangent to the sphere is taken as the third feasible coordinate;

[0099] If the first solution is greater than 0 and less than 1 and the second solution is greater than 1, the point of intersection with the sphere is taken as the fourth feasible coordinate;

[0100] The first feasible coordinate, the second feasible coordinate, the third feasible coordinate, and the fourth feasible coordinate are combined to obtain a set of feasible coordinate estimates.

[0101] To facilitate understanding by those skilled in the art, a set of best embodiments is provided below:

[0102] This embodiment will design and develop surgical positioning based on UWB technology, designing a complete surgical positioning solution, including theoretical and technical research, human body simulation modeling and the application of related technologies. Specifically, it includes the following steps:

[0103] 1. Establishing a high-precision human electromagnetic simulation model is an important prerequisite for adopting simulation calculation methods. In previous human channel characteristic simulation models, most of them use cylinders to depict the human torso and limbs, and use spheres or ellipses to represent the head. Of course, there are also models that use multi-layer planar stacking structures, with each plane layer representing tissues and organs of different thicknesses. Obviously, these models are relatively rough. Due to the irregular external shape of the human body, the complex interweaving of internal tissues and organs, and the different electromagnetic properties of different tissues, in order to improve the accuracy of the human electromagnetic simulation model, maximize the consideration of the various tissue effects of the human body, and reduce the complexity of modeling, this embodiment will use CT and MRI human body sections provided by Yale University for three-dimensional reconstruction to establish a human electromagnetic simulation model.

[0104] To use UWB technology to provide signal propagation within the human body using a human electromagnetic simulation model, a readily implementable channel model is necessary. Traditional FIT-based electromagnetic simulations require complex human electromagnetic models and are very time-consuming. Therefore, based on the above human electromagnetic simulation results, we will develop a more easily implementable channel statistical model to characterize the path loss characteristics of 2.5 to 6.0 GHz signals within the human body.

[0105] The path loss characteristic can be modeled as a function expression related to distance. The path loss of UWB signals in indoor and free space can generally be expressed by a logarithmic function. However, this logarithmic function is not applicable to the UWB channel in the human body. Therefore, the path loss modeling is changed to the following improved power law function form: loss =p0+α((d+d0) / d0) n (1)

[0106] Among them, p loss represents the path loss, p0 represents the reference value, d represents the depth from the body surface to the body, d0 represents the reference depth, n represents the path loss exponent, and α represents a constant.

[0107] 2. In commonly used communication distance calculation methods, the calculation principle of wireless communication distance is primarily influenced by three factors: transmission power, antenna gain, and propagation loss. Therefore, signal transmission distance is closely related to these factors. Propagation loss consists of path loss, shadow loss, and multipath loss. Wireless communication distance calculation is typically based on a free-space path loss model and other environmental parameters. Other environmental parameters, such as shadow loss, are affected by the channel environment, whereby signal power is reduced on obstructing surfaces due to absorption, diffraction, scattering, and reflection. Typically, shadow loss is used in conjunction with path loss to compensate for the discrepancy between the theoretical path loss formula and the actual received signal measured. Furthermore, small-scale channel fading is primarily affected by multipath effects. This experiment is based on UWB signal propagation through the human body. The corresponding path loss model has already been established in step 1 above in this embodiment. Furthermore, the transmission power, antenna gain, and other values ​​of the experimental equipment are generally determined by the respective equipment. To simplify the experimental results, this embodiment uses the simplest form.

[0108] After calculating the path loss using the path loss model, the received power can be calculated using the following formula according to the signal reception principle: Prx (dBm) = Ptx (dBm) + Gtx (dBi) + Grx (dBi) - L (dB) (2)

[0109] Among them, Prx (dBm) represents the received power, Ptx (dBm) represents the transmitted power, Gtx (dBi) represents the transmitting antenna gain, Grx (dBi) represents the receiving antenna gain, and L (dB) represents the path loss. (Due to the experimental surgical environment, the impact of other environmental losses can be ignored. Therefore, the main loss is the path loss, and L (dB) can be represented by the path loss.)

[0110] Finally, to estimate the signal propagation distance, we first need a minimum acceptable power (Prx_min). Using the known transmitter power (Ptx) and antenna gain (Gtx and Grx), we can calculate the loss (L). Then, by combining this loss with the free space path loss model and other environmental parameters, we can determine the distance. The free space path loss model is: L = 32.4 + 20*log(D) + 20*log(M) (3)

[0111] Where L represents signal loss in dB, D represents the free space propagation distance of the wireless signal in km, and M represents the propagation signal frequency in MHz.

[0112] In actual communication environments, satellite communications can use an ideal path loss model. However, in the actual operating room environment of this solution, obstacles such as surgical instruments and operating tables may absorb some of the signal energy. Therefore, the above formula needs to be further improved:

[0113] Where d0 represents the reference distance (i.e., reference depth), n represents the path loss exponent in different environments, L(d) represents the signal loss after partial absorption of the signal energy due to obstacles such as surgical instruments and operating tables, and d represents the depth from the body surface to the inside of the body.

[0114] 3. After obtaining the accurate distance calculation formulas, this embodiment will use the three-sphere intersection positioning method to calculate the target's location. The solution of the three-sphere intersection geometric positioning is mainly completed by solving the three-dimensional coordinates and distance formulas. It is often used for satellite positioning. Since the human body is a three-dimensional model, this method can be used for calculation. In this embodiment, three signal transmitters A, B and C are used (three signal transmitters with known spatial positions are fixed at three appropriate positions in the operating room respectively) and a receiving terminal R (the receiving terminal is set at a suitable position near the surgical site on the human body surface). Since the spatial position of the signal transmitter is known, the receiving terminal can obtain specific spatial position data through signal reception and analysis, and the user terminal can obtain the distance to the measured target through pseudo-range measurement. Based on the distance calculation method between two points in spatial coordinates, the receiving terminal can obtain three distance equations by observing the three signal transmitters. On the basis of no measurement error, these three distance equations can be used to calculate the two possible coordinate solutions of the receiving terminal (i.e., the feasible coordinate estimation set). Then, the target coordinates (x, y, z) can be obtained by further elimination through the least squares method. Among them, the three-sphere intersection positioning method is specifically as follows:

[0115] Assume that the three balls intersect at points P1(x1,y1,z1) and P2(x2,y2,z2), and let the coordinates of a point P in the line segment P1P2 be (x,y,z), then the coordinates of point P can be expressed as:

[0116] If the coordinates of the fourth transmitter are P3 (x3, y3, z3), and the distance between it and the receiving terminal is r, then the sphere with the transmitter as the center and the distance as the radius can be expressed as: (x-x3) 2 +(y-y3) 2 +(z-z3) 2 =r 2 (5)

[0117] Substituting equation 5 into equation 4, we get the quadratic equation: au 2+bu+c=0 (6)

[0118] in:

[0119] For the above quadratic equation, by (the discriminant of the root) Δ = b 2 -4ac can determine the number of intersections between the sphere and the line segment. If Δ<0, there are no intersections; if Δ>0, there are two intersections; and if Δ=0, there is exactly one intersection.

[0120] To solve for the target point's coordinates, we first use the three-sphere intersection algorithm to calculate two points. Then, using Δ in Equation 6, we determine the intersection of the line between these two points and the sphere. If there's no intersection, the measured distance is flawed and deviates from the true value. We set this value to r and repeat the process until an intersection is found. When an intersection occurs, or when Δ > 0, we solve for the value of u, which includes both u1 and u2, and make the following judgment:

[0121] (1) When u1 and u2 are less than 0, the line segment P1P2 has no intersection with the sphere, as shown in Figure 2(a). At this time, the final positioning point is the point P1 that is closer to the center of the sphere;

[0122] (2) When u1 < 0 and u2 > 1, the line segment P1P2 is inside the sphere and has no intersection with the sphere, as shown in Figure 2(b). At this time, the final positioning point is selected as point P1 which is closer to the center of the sphere;

[0123] (3) When u1=u2, the line segment P1P2 is tangent to the sphere at a point, as shown in Figure 2(c). At this point, the final positioning point is the tangent point P;

[0124] (4) When 0<u1<1<u2, the line segment P1P2 intersects the sphere at a point, as shown in Figure 2(d). At this point, the final positioning point is the intersection point P.

[0125] The coordinate position of the receiving terminal is obtained by further elimination through the least square method, including the steps of:

[0126] This embodiment defines For the receiving terminal (x u ,y u ) and the i-th transmitter (x i ,y i ) between the geometric distance d u,i The estimate is:

[0127] Expand Equation 8 using Taylor's formula and take its first-order term, then the reference point (x v ,y v ) is converted to: du,i =d v,i +a i,1 δ x +a i,2 δ y ,i=1,…,N (9)

[0128] Among them, δ x =x u -x v ,δ y =y u -y v , N is the number of transmitters, d v,i is the distance between the reference point and the i-th transmitter, that is:

[0129] will a i,1 and a i,2 Expressed as a differential expression, that is:

[0130] Based on Equation 9 Estimated d u,i , we can get the N equations of the system, namely:

[0131] It can be expressed as a matrix: Aδ=D δ=[δ x ,δ2] T

[0132] The least squares estimate of the parameter matrix is: δ=(A T A) -1 (A T D) (14)

[0133] When A is a non-singular matrix, A can be directly inverted to obtain A -1 ; When A is a singular matrix, the generalized inverse A can be obtained for A + , the inverse process can be solved by the singular value decomposition (SVD) method. From this, we can solve formula 13 and estimate δ, and the coordinates of the beacon point can be obtained as:

[0134] Estimation is performed using iteration and recursion. A point in the measurement environment is selected as the reference point for the first iteration. For subsequent iterations, the solution obtained is the (n-1)th iteration, meaning the solution for the (n-1)th iteration serves as the reference point for the nth iteration. The coordinate position of the receiving terminal is obtained by plane fitting the set of feasible coordinate estimates using the least squares method.

[0135] Finally, the surgical positioning of the target to be measured is performed according to the coordinate position of the receiving terminal.

[0136] In this embodiment, a human-based channel statistical model was studied based on a highly accurate three-dimensional human electromagnetic simulation model. Through practical analysis of the results, a simplified and improved method for the channel statistical model was proposed, resulting in a human-based path loss model. This provides a valuable reference for future research in this area. Building on the aforementioned embodiments, a four-base-station-one-beacon model was established using the principle of the three-sphere intersection positioning method for simulation verification. The position coordinates of the beacon point (i.e., the receiving terminal) were calculated using the least squares method to verify their accuracy. The circular error probability (CEP) was used to determine whether the calculated position coordinates met the allowable error accuracy. The entire process employed extremely rigorous logic, ultimately achieving a final result within the allowable error range of only 0.083 cm. This embodiment addresses the current challenges of surgical positioning by proposing a novel approach. While ensuring human safety and accurate results, it leverages the unique characteristics of UWB signal propagation to minimize signal transmission power, resulting in strong multipath resolution, low system complexity and cost, and high theoretical ranging accuracy. The impact of this approach was comprehensively evaluated, and a specific solution based on practical application was proposed.

[0137] It should be noted that, in this embodiment, the coordinate position of the receiving terminal may also be calculated using Fang's algorithm model, which is not specifically limited in this embodiment.

[0138] 3 , an embodiment of the present invention further provides a surgical positioning system based on UWB technology. The surgical positioning system based on UWB technology includes a first model building unit 100, a second model building unit 200, a third model building unit 300, a first data calculation unit 400, a second data calculation unit 500, a third data calculation unit 600, and a target positioning unit 700, wherein:

[0139] The first model building unit 100 is used to build a human electromagnetic simulation model, and use UWB technology to provide a signal propagating in the human body in the human electromagnetic simulation model to build a channel model;

[0140] The second model building unit 200 is used to build a path loss model for calculating the path loss in the channel model;

[0141] The third model building unit 300 is used to build a mathematical model including received power and path loss according to the signal reception principle;

[0142] A first data calculation unit 400 is configured to calculate a first path loss using a path loss model and then calculate a received power using a mathematical model;

[0143] The second data calculation unit 500 is configured to calculate a second path loss according to a mathematical model at a minimum received power;

[0144] A third data calculation unit 600 is configured to calculate a communication distance based on the second path loss, a free space path loss model, and environmental parameters including shadow loss;

[0145] The target positioning unit 700 is used to perform surgical positioning on the target according to the communication distance by using a three-ball intersection positioning method.

[0146] It should be noted that since the surgical positioning system based on UWB technology in this embodiment and the above-mentioned surgical positioning method based on UWB technology are based on the same inventive concept, the corresponding contents in the method embodiment are also applicable to this system embodiment and will not be described in detail here.

[0147] Referring to FIG4 , an embodiment of the present application further provides a surgical positioning device based on UWB technology. The surgical positioning device based on UWB technology includes:

[0148] at least one memory;

[0149] at least one processor;

[0150] at least one program;

[0151] The programs are stored in the memory, and the processor executes at least one program to implement the above-mentioned surgical positioning method based on UWB technology in the present disclosure.

[0152] The electronic device may be any intelligent terminal including a mobile phone, a tablet computer, a personal digital assistant (PDA), a car computer, etc.

[0153] The electronic device according to the embodiment of the present application is described in detail below.

[0154] The processor 1600 may be implemented as a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is configured to execute relevant programs to implement the technical solutions provided by the embodiments of the present disclosure.

[0155] The memory 1700 can be implemented in the form of a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 1700 can store an operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 1700 and is called by the processor 1600 to execute the surgical positioning method based on UWB technology in the embodiments of this disclosure.

[0156] Input / output interface 1800, used for information input and output;

[0157] Communication interface 1900, used to implement communication interaction between this device and other devices, which can be achieved through wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, WiFi, Bluetooth, etc.);

[0158] bus 2000 , which transmits information between various components of the device (e.g., processor 1600 , memory 1700 , input / output interface 1800 , and communication interface 1900 );

[0159] The processor 1600 , the memory 1700 , the input / output interface 1800 , and the communication interface 1900 are connected to each other in communication within the device via the bus 2000 .

[0160] An embodiment of the present disclosure further provides a storage medium, which is a computer-readable storage medium. The computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the above-mentioned surgical positioning method based on UWB technology.

[0161] The memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory may include a high-speed random access memory and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory may optionally include a memory remotely arranged relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0162] The embodiments described in the embodiments of the present disclosure are intended to more clearly illustrate the technical solutions of the embodiments of the present disclosure and do not constitute a limitation on the technical solutions provided by the embodiments of the present disclosure. Those skilled in the art will appreciate that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of the present disclosure are also applicable to similar technical problems.

[0163] Those skilled in the art will understand that the technical solutions shown in the drawings do not constitute a limitation on the embodiments of the present disclosure, and may include more or fewer steps than shown in the drawings, or a combination of certain steps, or different steps.

[0164] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, i.e., they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of this embodiment.

[0165] Those skilled in the art will appreciate that all or some of the steps in the methods, systems, and functional modules / units in the devices disclosed above may be implemented as software, firmware, hardware, or appropriate combinations thereof.

[0166] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0167] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0168] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0169] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0170] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0171] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including multiple instructions for enabling an electronic device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes various media that can store programs, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk. The embodiments of the present application are described in detail above in conjunction with the accompanying drawings, but the present application is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in the relevant technical field without departing from the purpose of the present application.

Claims

1. A surgical positioning method based on UWB technology, characterized in that: The surgical positioning method based on UWB technology includes: Establishing a human electromagnetic simulation model, and using UWB technology to provide a signal propagated in a human body in the human electromagnetic simulation model, and establishing a channel model; Constructing a path loss model for calculating path loss in the channel model; According to the signal reception principle, a mathematical model including the received power and path loss is constructed; After calculating the first path loss through the path loss model, calculating the received power according to the mathematical model; Under the minimum received power, calculating the second path loss according to the mathematical model; Calculating a communication distance based on the second path loss, a free space path loss model, and environmental parameters including shadow loss; According to the communication distance, a three-ball intersection positioning method is used to perform surgical positioning on the target to be measured.

2. The surgical positioning method based on UWB technology according to claim 1, characterized in that: The path loss model used to calculate the channel model is constructed in the following manner: loss =p0+α((d+d0) / d0) n Among them, p loss represents path loss, p0 represents reference value, d represents depth from body surface to body interior, d0 represents reference depth, n represents path loss exponent, and α represents constant.

3. The surgical positioning method based on UWB technology according to claim 1, characterized in that: The mathematical model including the received power and path loss is constructed as follows: Prx (dBm) = Ptx (dBm) + Gtx (dBi) + Grx (dBi) - L (dB) Among them, Prx (dBm) represents the receiving power, Ptx (dBm) represents the transmitting power, Gtx (dBi) represents the transmitting antenna gain, Grx (dBi) represents the receiving antenna gain, and L (dB) represents the path loss.

4. The surgical positioning method based on UWB technology according to claim 1, characterized in that: The calculating the communication distance based on the second path loss, the free space path loss model and the environmental parameters including the shadow loss includes: Calculating a signal loss based on the environmental parameters including the shadow loss and the second path loss; Based on the signal loss, the free space path loss model is used to calculate the communication distance; wherein the free space path loss model is used to calculate the communication distance. The spatial path loss model is: L=32.4+20*log(D)+20*log(M) Among them, L represents signal loss, D represents the free space propagation distance of the wireless signal, and M represents the propagation signal frequency.

5. The surgical positioning method based on UWB technology according to claim 1, characterized in that: The method of using a three-ball intersection positioning method to perform surgical positioning on the target to be measured according to the communication distance includes: Establishing a ranging model including four transmitting devices with known spatial positions and a receiving terminal, and calculating the communication distance from each of the transmitting devices to the receiving terminal; According to the communication distance and the ranging model, a feasible coordinate estimation set of the receiving terminal is calculated using a three-sphere intersection positioning method; The feasible coordinate estimation set is plane-fitted using the least square method to obtain the coordinate position of the receiving terminal, and the target to be measured is surgically positioned according to the coordinate position.

6. The surgical positioning method based on UWB technology according to claim 5, characterized in that: The step of calculating a feasible coordinate estimation set of the receiving terminal using a three-sphere intersection positioning method according to the communication distance and the ranging model includes: Based on the transmitting device and the receiving terminal with three known spatial positions in the ranging model, a three-ball intersection positioning method is used to obtain two points where the three balls intersect; constructing a sphere using a transmitting device at a fourth known spatial position, the receiving terminal, and a communication distance between the transmitting device at the fourth known spatial position and the receiving terminal; A quadratic equation is calculated based on the equation expression of the sphere and the coordinates of the two points; Using the discriminant of the quadratic equation to determine the number of intersections between the straight line between the two points and the sphere; If there is an intersection point between the straight line between the two points and the sphere, a feasible coordinate estimation set of the receiving terminal is calculated using the solution of the quadratic equation.

7. The surgical positioning method based on UWB technology according to claim 6, characterized in that: The calculating the feasible coordinate estimation set of the receiving terminal by using the solution of the quadratic equation includes: Based on the first solution and the second solution of the quadratic equation, if the first solution and the second solution are both less than 0, selecting a point closer to the center of the sphere as a first feasible coordinate; If the first solution is less than 0 and the second solution is greater than 1, then a point closer to the center of the sphere is selected as the second feasible coordinate; If the first solution is equal to the second solution, the point tangent to the sphere is taken as the third feasible coordinate; If the first solution is greater than 0 and less than 1 and the second solution is greater than 1, the point intersecting with the sphere is taken as the fourth feasible coordinate; The first feasible coordinates, the second feasible coordinates, the third feasible coordinates and the fourth feasible coordinates are combined to obtain a feasible coordinate estimation set.

8. A surgical positioning system based on UWB technology, characterized in that: The surgical positioning system based on UWB technology includes: The first model building unit is used to build a human electromagnetic simulation model, and use UWB technology to provide a signal propagated in the human body in the human electromagnetic simulation model to build a channel model; A second model building unit, used to build a path loss model for calculating the path loss in the channel model; A third model building unit is used to build a mathematical model including receiving power and path loss according to the signal receiving principle; A first data calculation unit, configured to calculate a first path loss by using the path loss model and then calculate a received power according to the mathematical model; A second data calculation unit, configured to calculate a second path loss according to the mathematical model at a minimum received power; a third data calculation unit, configured to calculate a communication distance based on the second path loss, a free space path loss model, and environmental parameters including shadow loss; The target positioning unit is used to perform surgical positioning on the target according to the communication distance by adopting a three-ball intersection positioning method.

9. A surgical positioning device based on UWB technology, characterized in that: It includes at least one control processor and a memory for communicating with the at least one control processor; the memory stores instructions that can be executed by the at least one control processor, and the instructions are executed by the at least one control processor to enable the at least one control processor to execute the surgical positioning method based on UWB technology as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the surgical positioning method based on UWB technology as described in any one of claims 1 to 7.

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