Weak magnetic field detection methods and endoscope detectors

Abstract

This invention discloses a weak magnetic field detection method and an endoscopic detection device. The weak magnetic field detection method is used to detect weakly magnetic medical devices within non-magnetic cavities. It includes: acquiring a magnetic field observation vector formed by at least one observation point on a reference spherical model after a change in the magnetic field; wherein the reference spherical model represents the geomagnetic field and has a first geomagnetic radius; if the magnitude of the magnetic field observation vector and the first geomagnetic radius satisfy a preset quantitative relationship, it is determined that a weak magnetic source exists within the non-magnetic cavity, and a presence signal is output. The weak magnetic field detection method provided by this invention only requires receiving the weak magnetic field, thus avoiding high-intensity radiation that could damage the non-magnetic cavity. Furthermore, by implementing a fitted spherical model and simple vector judgment, it achieves the technical advantages of fast detection speed, simple process, and low false trigger probability.

Description

Technical Field

[0001] This invention relates to the field of medical technology, and in particular to a weak magnetic field detection method and an endoscope detector. Background Technology

[0002] Currently, endoscopic expulsion detection methods in the medical field mainly focus on emitting sound or light signals when the endoscope is expelled from the body to alert the patient to retrieve it. However, this approach offers a poor user experience and is prone to accidental triggering while the endoscope is inside the patient, or failure to trigger an alarm due to feces obstructing the light sensor after expulsion. Existing technologies also employ X-ray imaging to detect the interior of the patient's digestive tract and determine the presence of an endoscope. While this accurately identifies the endoscope's location, the X-ray imaging process is complex, time-consuming, and potentially harmful to the human body. Therefore, developing a weak magnetic field detection method with low accidental triggering probability, no harm to the human body, convenient and rapid detection process, and applicability in the medical field is a pressing technical problem. Summary of the Invention

[0003] One of the objectives of this invention is to provide a weak magnetic field detection method to solve the technical problems in the prior art, such as poor detection effect, slow detection speed, harmfulness to the human body during the detection process, and high probability of false triggering of weak magnetic medical devices.

[0004] One of the objectives of this invention is to provide an endoscope detector.

[0005] To achieve one of the above-mentioned objectives, one embodiment of the present invention provides a weak magnetic field detection method for detecting weak magnetic medical devices within a non-magnetic cavity, comprising: acquiring a magnetic field observation vector formed by at least one observation point on a reference spherical model after a change in the magnetic field; wherein the reference spherical model represents the geomagnetic field and has a first geomagnetic radius; if the magnitude of the magnetic field observation vector and the first geomagnetic radius satisfy a preset quantitative relationship, then it is determined that a weak magnetic source exists within the non-magnetic cavity, and a presence signal is output.

[0006] As a further improvement of one embodiment of the present invention, the method specifically includes: if the magnitude of the observed magnetic field vector is less than a first criterion value, or the magnitude of the observed magnetic field vector is greater than a second criterion value, then it is determined that a weak magnetic source exists in the non-magnetic cavity, and an existence signal is output; wherein, the first criterion value is equal to the difference between the first geomagnetic radius and the first tolerance, the second criterion value is equal to the sum of the first geomagnetic radius and the first tolerance, and the first tolerance characterizes the difference between the magnitudes of different geomagnetic field vectors in the reference sphere model.

[0007] As a further improvement of one embodiment of the present invention, the method further includes: receiving the presence signal, obtaining the number and / or average duration of the presence signal; and outputting an alarm signal if the number and / or average duration of the presence signal is greater than a preset value.

[0008] As a further improvement of one embodiment of the present invention, the method further includes: receiving the presence signal, acquiring the magnitudes of a plurality of magnetic field observation vectors within a preset time range; calculating the standard deviation of the magnitudes of the plurality of magnetic field observation vectors to obtain the magnetic observation standard deviation; and outputting an alarm signal when the magnetic observation standard deviation is less than or equal to a preset dynamic magnetic field threshold.

[0009] As a further improvement of one embodiment of the present invention, the method specifically includes: acquiring a magnetic field observation vector formed by at least one observation point on a reference sphere model after a change in the magnetic field, and acceleration and rotational angular velocity change signals during the magnetic field change process, to obtain the magnitude, acceleration data, and gyroscope data of the magnetic field observation vector; the method further includes: receiving the presence signal, calculating the standard deviation of the acceleration data, and / or the average value of the gyroscope data, to obtain the velocity standard deviation and / or the gyroscope mean; if the velocity standard deviation is less than or equal to a preset dynamic velocity threshold, and / or when the gyroscope mean is less than or equal to a preset dynamic rotation threshold, an alarm signal is output.

[0010] As a further improvement of one embodiment of the present invention, the method specifically includes: acquiring geomagnetic field data from multiple directions, fitting the reference sphere model in a three-dimensional coordinate system; calculating geomagnetic field vectors from multiple directions based on the geomagnetic field data; calculating a first tolerance in the preset quantitative relationship based on the magnitude of the geomagnetic field vectors; wherein the first tolerance characterizes the difference between the magnitudes of different geomagnetic field vectors in the reference sphere model, the geomagnetic field vectors are configured as directed line segments pointing from the center of the reference sphere model to the position of the geomagnetic field data in the three-dimensional coordinate system; the first tolerance is configured as an integer multiple of the standard deviation of the magnitude of the geomagnetic field vectors.

[0011] As a further improvement of one embodiment of the present invention, the method further includes: acquiring geomagnetic field data from multiple magnetic sensors in multiple orientations; fitting multiple spherical models in a three-dimensional coordinate system to obtain multiple calibration spherical models; calculating the center of each calibration spherical model and the vector from the center of the reference spherical model to the calibration point to obtain multiple calibration sphere centers and calibration vectors; calibrating the magnitude of multiple calibration vectors using the calibration vector of one of the multiple calibration spherical models to obtain multiple data vectors; calculating multiple data points based on the data vectors and the corresponding calibration sphere centers, and calculating multiple data points in a three-dimensional coordinate system based on the data points. A reference spherical model is fitted in the system; wherein the magnetic field data is distributed on the calibration spherical model to form multiple calibration points; the calibration vector is one of the calibration vectors of the calibration spherical model in a preset direction; the method specifically includes: obtaining the vector corresponding to the observation point in a first state to obtain a first observation vector; obtaining the vector corresponding to the observation point in a second state and calibrating it with the calibration vector to obtain a second observation vector; if the magnitude of the second observation vector and the first geomagnetic radius satisfy a preset quantitative relationship, then it is determined that the weak magnetic source exists in the non-magnetic cavity, and the presence signal is output.

[0012] As a further improvement of one embodiment of the present invention, the calibration sphere model is an ellipsoid, the preset direction is the major axis direction of the ellipsoid, and the method specifically includes: calculating multiple calibration parameters based on the calibration vector and the magnitudes of multiple calibration quantities; wherein the calibration parameter is the quotient of the magnitude of the calibration vector and the magnitude of the calibration quantity; calibrating the magnitudes of the multiple calibration quantities according to the multiple calibration parameters to obtain multiple data vectors; the method specifically includes: obtaining the calibration parameters corresponding to the first observation vector to obtain observation calibration parameters; obtaining the vector corresponding to the observation point in the second state, calibrating it with the observation calibration parameters to obtain the second observation vector.

[0013] As a further improvement of one embodiment of the present invention, the method further includes: if the magnitude of the magnetic field observation vector and the first geomagnetic radius do not satisfy a preset quantitative relationship, then track the change in the distance between at least two observation points on the reference sphere model with the magnetic field to obtain the distance change value; if the distance change value and the preset distance change threshold satisfy a preset quantitative relationship, then determine that there is a weak magnetic source in the non-magnetic cavity.

[0014] As a further improvement of one embodiment of the present invention, the method further includes: tracking the dispersion of at least two sets of observation points on the reference sphere model to obtain first dispersion data and second dispersion data, and tracking the overall dispersion of the at least two sets of observation points to obtain global dispersion data, which are used to characterize the change of the distance between observation points with the magnetic field; if the global dispersion data and the preset distance change threshold, the first dispersion data and the second dispersion data satisfy a preset quantitative relationship, then it is determined that a weak magnetic source exists in the non-magnetic cavity.

[0015] To achieve one of the above-mentioned objectives, one embodiment of the present invention provides an endoscope detector for detecting endoscopes inside the human body. The endoscope is configured to have weak magnetism. The endoscope detector includes a detection panel and a handle connected to the detection panel. The detection panel includes a display surface and a sensing surface arranged opposite to each other. The endoscope detector is configured to implement the weak magnetic detection method as described in claims 1-8.

[0016] As a further improvement of one embodiment of the present invention, the display surface is provided with an alarm light and a status light configured in a ring shape, and the sensing surface is uniformly distributed with at least four sensing units, each sensing unit including at least two magnetic sensors, one of which is disposed on the side close to the geometric center of the sensing surface, and the other is disposed on the side away from the geometric center.

[0017] Compared with existing technologies, this invention utilizes the weak magnetism carried by medical devices to detect medical devices inside non-magnetic cavities. By fitting a reference sphere model representing the strength of the Earth's magnetic field, the vector changes of a certain data point in the reference sphere model under different states are tracked, and comparisons are made based on certain preset quantitative relationships. Since the detection process only needs to receive the Earth's magnetic field and the weak magnetic field emitted by the medical device, and does not send signals to the non-magnetic cavity, it will not generate high-intensity radiation that could damage the non-magnetic cavity. At the same time, the technical solution based on fitting a sphere model and making vector judgments can achieve the technical effects of fast detection speed, simple process and low probability of false triggering. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the first side of the endoscope detection device in one embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the second side of the endoscope detection device in one embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of the third side of the endoscope detection device in another embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of the fourth side of the endoscope detection device in another embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of the cooperation structure between the endoscope detection device and the human body in one embodiment of the present invention;

[0023] Figure 6 This is a schematic diagram of the scanning trajectory of the endoscope detection device in one embodiment of the present invention;

[0024] Figure 7 This is a schematic diagram of the scanning trajectory of the endoscope detection device in another embodiment of the present invention;

[0025] Figure 8 This is a schematic diagram of the steps of a weak magnetic field detection method in one embodiment of the present invention;

[0026] Figure 9 This is a schematic diagram of the magnetic field distribution in a specific application scenario of the weak magnetic field detection method according to one embodiment of the present invention;

[0027] Figure 10 This is a schematic diagram of the steps of a weak magnetic field detection method in another embodiment of the present invention;

[0028] Figure 11 This is a schematic diagram of the steps of the first embodiment of the weak magnetic field detection method according to one embodiment of the present invention;

[0029] Figure 12 This is a schematic diagram of signal changes in the first embodiment of the weak magnetic field detection method according to one embodiment of the present invention;

[0030] Figure 13 This is a schematic diagram of the steps of the second embodiment of the weak magnetic field detection method in one embodiment of the present invention;

[0031] Figure 14 This is a schematic diagram of the steps of the third embodiment of the weak magnetic field detection method in one embodiment of the present invention;

[0032] Figure 15 This is a schematic diagram of the steps of a weak magnetic field detection method in another embodiment of the present invention;

[0033] Figure 16 This is a schematic diagram illustrating the steps of a specific example of a weak magnetic field detection method in another embodiment of the present invention;

[0034] Figure 17 This is a schematic diagram of the distribution of a sphere model in a specific application scenario of the weak magnetic field detection method in another embodiment of the present invention;

[0035] Figure 18This is a schematic diagram of the distribution of a sphere model in another specific application scenario of the weak magnetic field detection method in another embodiment of the present invention;

[0036] Figure 19 This is a schematic diagram of the distribution of a reference sphere model in a specific application scenario of the weak magnetic field detection method in another embodiment of the present invention;

[0037] Figure 20 This is a schematic diagram of the steps of a first embodiment of a specific example of a weak magnetic field detection method in another embodiment of the present invention;

[0038] Figure 21 This is a schematic diagram of the steps of a second embodiment of a specific example of a weak magnetic field detection method in another embodiment of the present invention;

[0039] Figure 22 This is a schematic diagram of the magnetic field distribution in a specific application scenario of the weak magnetic field detection method in another embodiment of the present invention;

[0040] Figure 23 This is a schematic diagram showing the distribution of the observation point change process in a specific application scenario of the weak magnetic field detection method in another embodiment of the present invention;

[0041] Figure 24 This is a schematic diagram illustrating two possible distributions of observation points after changes in a specific application scenario of the weak magnetic field detection method in another embodiment of the present invention. Detailed Implementation

[0042] The present invention will now be described in detail with reference to the specific embodiments shown in the accompanying drawings. However, these embodiments do not limit the present invention, and any structural, methodological, or functional modifications made by those skilled in the art based on these embodiments are included within the scope of protection of the present invention.

[0043] It should be noted that the term "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Furthermore, the terms "first," "second," "third," "fourth," "fifth," "sixth," "seventh," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] Weak magnetic field detection tools are often configured to carry a weak magnetic field detection method to detect weak magnetic devices inside non-magnetic cavities. Because the magnetism of weak magnetic devices is relatively weak, they are usually difficult to detect accurately after being superimposed with external interference such as the Earth's magnetic field. This makes it impossible for the operator to accurately know whether there are still weak magnetic devices inside the non-magnetic cavity and the current status of the weak magnetic devices.

[0045] In the medical field, this problem typically manifests as the difficulty for medical professionals to determine whether an endoscope, which can be considered a weak magnetic device, is still present in the human body, which can be viewed as a non-magnetic cavity. If the endoscope (especially a capsule endoscope) is not successfully removed from the body, its prolonged presence can complicate subsequent medical procedures and may even cause secondary damage to the body.

[0046] Based on this, the present invention provides an endoscope detection device for detecting endoscopes inside the human body, wherein the endoscope is configured to have weak magnetism. Of course, the endoscope detection device, when facing similar accuracy requirements, can also be further applied to other technical fields to detect any weakly magnetic devices existing in non-magnetic cavities.

[0047] In one embodiment of the present invention, the structure of the endoscope detection device 1 is as follows: Figure 1 and Figure 2 As shown, the device includes a detection panel 11 and a handle 12 pivotally connected to the detection panel 11. The detection panel 11 may further include a display surface 111 and a sensing surface 112 disposed opposite to each other. The display surface 111 may be disposed on a first side of the endoscope detection device 1 (or detection panel 11), while the sensing surface 112 may be disposed on a second side of the endoscope detection device 1 (or detection panel 11). Preferably, the endoscope detection device 1 is configured to implement a weak magnetic detection method to achieve the endoscope detection function.

[0048] Furthermore, the handle 12 can be configured as a long strip and can be arranged in a first plane along its length. The first plane can be configured to be perpendicular to the plane where the detection panel 11 is located. Preferably, the handle 12 can be configured to rotate within the first plane around its pivot connection with the detection panel 11 to adjust the relative position of the handle 12 and the detection panel 11. In actual use, the operator holds the handle 12 and places the detection panel 11 close to the non-magnetic cavity. Based on the above structural configuration, the operator can easily adjust the posture of the detection panel 11 by adjusting the relative position of the two. Of course, in other embodiments, the detection panel 11 and the handle 12 can also be configured as a fixed connection with a fixed relative position. This could be that the handle 12 and the detection panel 11 extend along the same horizontal plane, or that the handle 12 is angled to the plane where the detection panel 11 is located, to facilitate the detection panel 11 being close to the non-magnetic cavity to be detected.

[0049] In this embodiment, the handle 12 may further be provided with an indicator light 121 for indicating the power supply status and / or fault status of the endoscope probe 1. For example, in one case, the indicator light 121 is configured to emit a first color light when charging, a second color light when in use, and / or a third color light when the power is low. In another case, the indicator light 121 is configured to be at least two, so as to indicate the current power supply status by the number of indicator lights 121 lit. In yet another case, the indicator light 121 is configured to emit a flashing or continuous light to indicate when an abnormal operation of the internal components of the endoscope probe 1 is detected.

[0050] The handle 12 may further include a receiving compartment 122, which can be configured as a battery compartment to house a power supply battery, or as a control compartment to house components used for weak magnetic field detection. For aesthetic and ease of use, the indicator light 121 is located on the side of the handle 12 closer to the detection panel 11, while the receiving compartment 122 is located on the side of the handle 12 away from the detection panel 11. This allows the operator's hand to cover the receiving compartment 122 to protect the internal components without obstructing the indicator light 121, thus facilitating the viewing of the current status of the endoscope detection device 1. For the same reason, at least the indicator light 121 can be configured to be located on the same side of the display surface 111 (which may be the aforementioned first side).

[0051] Of course, the cover plate of the empty compartment 122 exposed to the outside can be configured to be in the same plane as other parts of the handle 12 to improve the integrity of the handle 12. Considering the benefits of grip stability, the cover plate can also be configured to protrude from other parts of the handle 12 and form an ergonomic shape, thereby increasing the friction between the palm and the handle 12 and enhancing the grip effect.

[0052] Preferably, the display surface 111 may further include an alarm light 1111 and a status light 1112 configured as annular rings. Of course, the alarm light 1111 and the status light 1112 may also be configured as arcs or other shapes. For example, the alarm light 1111 may be configured as a semi-circular arc located on the display surface 111 at a position away from or near the handle 12, and the status light 1112 may be configured as a semi-circular arc located on the display surface 111 at a position near or far from the handle 12.

[0053] Specifically, the alarm light 1111 and the status light 1112 can be configured as an integrated light strip, and can be illuminated as a whole at a preset brightness or at different levels of brightness after a preset alarm condition is detected or a preset status indication signal is received. The alarm light 1111 can also be configured to be illuminated partially at a preset brightness or partially at different levels of brightness. In particular, in embodiments where multiple magnetic sensors are provided on the sensing surface 112, multiple parts of the alarm light 1111 can be directly or indirectly connected to the multiple magnetic sensors, so that when the data detected by one or more magnetic sensors meets the preset alarm condition, it can be reflected in a part of the alarm light 1111 to issue an alarm indication. In one embodiment, the preset alarm condition can be that the corresponding magnetic sensor detects a weak magnetic device (such as a capsule endoscope inside the human body) or a weak magnetic signal in a non-magnetic cavity. Based on this, for example, when the weak magnetic device or weak magnetic signal is located in the upper left corner of the detection panel 11, at least part of the arc of the upper left corner of the alarm light 1111 will be lit, thereby displaying the detected weak magnetic condition and instructing the operator to hold the endoscope detection device 1 and move it towards the upper left, thereby further and quickly determining the location of the weak magnetic device and playing the role of scanning path guidance.

[0054] In addition, the status light 1112 can be used to indicate the current working state of the endoscope probe 1, such as being in sensing state, calibration state, or initialization state. The distinction between these states can be formed by referring to the previous description of the working state of the alarm light 1111, or it can be formed by using different colored lights and flashing methods that are different from those described above. For example, when the endoscope probe 1 is in sensing state, the status light 1112 is configured to be constantly lit; when the endoscope probe 1 is in calibration state, the status light 1112 is configured to flash; and when the endoscope probe 1 is in initialization state, the status light 1112 is configured to have a "marquee" effect.

[0055] Figure 2 The structure of the second side of the endoscope probe 1 is shown, wherein at least four sensing units 1120 are evenly distributed on the sensing surface 112. The handle 12, as... Figure 2 In the case where the sensor units 1120 extend vertically as shown, the at least four sensing units 1120 can be arranged in a cross shape, and the sensing units 1120 located on the left and right sides can be configured to extend horizontally, while the sensing units 1120 located on the top and bottom sides can be configured to extend vertically. Of course, in the same case, the at least four sensing units 1120 can also be arranged in a cross shape, and are mutually centrally symmetrical and axially symmetrical.

[0056] Furthermore, the sensing unit 1120 may include at least two magnetic sensors, with one of the magnetic sensors disposed on the side close to the geometric center of the sensing surface 112, and the other disposed on the side away from the geometric center. Figure 2 In the illustrated embodiment, the sensing unit 1120 may include a first magnetic sensor 1120A and a second magnetic sensor 1120B. The first sensor 1120A and the second magnetic sensor 1120B are spaced apart along the length of the sensing unit 1120, with the first magnetic sensor 1120A located near the geometric center of the sensing surface 112 and the second magnetic sensor 1120B located away from the geometric center of the sensing surface 112. Other magnetic sensors may have the same configuration as described above, or they may have other configurations.

[0057] Understandably, eight sensing units 1120 on the sensing surface 112 can be configured, arranged along a cross direction and an X direction respectively. Of course, the arrangement of sensing units 1120 in this invention is not limited to the specific examples provided above. Meanwhile, the function of configuring two magnetic sensors within a single sensing unit 1120 is to improve the anti-interference capability of the endoscope detection device 1. Based on this, the number of magnetic sensors within a single sensing unit 1120 can be increased or decreased according to needs and cost control considerations.

[0058] In one embodiment of the endoscope detection device 1 provided above, such as Figure 1 and Figure 2 As shown, the detection panel 11 is configured with a circular extended surface, thereby accommodating more sensing units 1120 in a smaller space and forming a more aesthetically pleasing shape. Of course, as... Figure 3 and Figure 4 In another embodiment shown, the probe panel 11 can also be configured to have an extended surface with a rectangular or rounded rectangle shape, thereby configuring the endoscope probe device 1 to have a large length component, which is sufficient to extend into a narrow space, expanding the applicable scenarios of the device and making it easier to store.

[0059] In this other embodiment, such as Figure 3 and Figure 4 As shown, the endoscope detection device 1 may also include a detection panel 11 and a handle 12 connected to the detection panel 11. The detection panel 11 may also include a display surface 111 and a sensing surface 112 arranged opposite to each other. The endoscope detection device 1 may also be configured to implement a weak magnetic detection method to detect a weakly magnetic endoscope in the human body.

[0060] In an embodiment where the detection panel 11 is configured with a rounded rectangular extended surface, the alarm light 1111 and status light 1112 in the display surface 111 can also be configured as strips with the same rounded rectangular shape to maintain consistency in design language. Similar to the previous embodiment, the alarm light 1111 can be located outside the status light 1112 and arranged along the edge of the detection panel 11. Meanwhile, to maintain the portability of the endoscope detection device 1 as much as possible without sacrificing its sensing accuracy, multiple sensing elements 1120 can be spaced apart along the length extension direction of the detection panel 11, preferably five, so that detection can be achieved at different positions along the length extension direction. Of course, in this configuration, the alarm light 1111 and the sensing elements 1120 can also be configured to have the connection relationship and functions described above to achieve the technical effect of endoscope tracking and navigation.

[0061] Because sufficient space needs to be provided for the sensing element 1120, the detection panel 11 is configured to be relatively long. Therefore, in this embodiment, the length of the handle 12 can be adaptively shortened to maintain the overall size balance of the endoscope detection device 1. Simultaneously, the connection between the handle 12 and the detection panel 11 can be configured as a simple fixed connection, thereby facilitating the operator's grip on the handle 12 and control of the position and orientation of the detection panel 11. Similarly, the handle 12 can also be equipped with an indicator light 121 and an empty compartment 122, and adopt the functional configuration provided in the previous embodiment.

[0062] The rounded rectangular shape of the detection panel 11 provides a larger coverage area for the sensing surface 112, making the scanning process faster. Of course, this invention is not limited to the two shape configurations described above. Inspired by the above configurations, various other fixed-shape configurations or variable-shape configurations can be derived. Furthermore, although the sensing elements 1120 are configured as uniformly distributed on the sensing surface 112 with a fixed relative position, this does not preclude the implementation of flexible disassembly and / or adjustment of their relative positions. Those skilled in the art can make substitutions as needed. It is noteworthy that, in terms of selection, the magnetic sensor can be configured as an AMR (Anisotropic Magnetoresistance) sensor or a TMR (Tunneling Magnetoresistance) sensor.

[0063] Figure 5The cooperation state between the endoscopic detection device 1 and the human body 2 is shown. Since the detection depth of the endoscopic detection device 1 is greatly affected by the magnetic source intensity, when detecting the magnet set in the endoscope and the magnetic sensor is facing the north and south poles of the magnet, it can reach 20 cm to 30 cm. Based on this, the endoscopic detection device 1 can be scanned close to the surface of the human abdomen 21 so that the detection range 100 of the endoscopic detection device 1 is sufficient to cover the part between the surface of the human abdomen 21 and the human spine 22.

[0064] In addition, although ferromagnetic materials such as metals have a certain interference on the detection process of the endoscopic detection device 1, when there is no obvious ferromagnetic substance on the surface of the human abdomen 21 (such as on clothes), the detection process can still proceed normally. At the same time, when the detection panel 11 of the endoscopic detection device 1 is close to the surface of the human abdomen 21, an angle can be formed between the detection panel 11 and the handle 12, which is convenient for the operator to hold, and it can be ensured that during the process of moving the endoscopic detection device 1, the detection panel 11 is always close to the human abdomen 21.

[0065] For the endoscopic detection device 1 provided by the above two embodiments, different scanning steps can be respectively provided. As Figure 6 shows the scanning steps of the endoscopic detection device 1 provided by the previous embodiment. Based on the above structural configuration, the detection range 100 formed by the endoscopic detection device 1 can be the same circle. When facing a similar rectangular待测区域200 on the human body, due to its relatively small and light weight, it can be scanned in a broken line trajectory, such as an S shape or a "ji" shape. As Figure 7 shows the scanning steps of the endoscopic detection device 1 provided by the latter embodiment. Based on the above structural configuration, the detection range 100 formed by the endoscopic detection device 1 is the same strip shape. When facing the待测区域200, the advantage of its large coverage area can be utilized for linear scanning, such as scanning back and forth along the diagonal of the待测区域200. Of course, any of the above scanning methods can be completed by holding the handle 12 pivotally connected or fixedly connected to the detection panel 11.

[0066] As Figure 8 shown, an embodiment of the present invention provides a weak magnetic detection method, which can be used to detect weak magnetic medical devices in a non-magnetic cavity, such as the endoscope for detecting the human body described above. The weak magnetic detection method specifically includes:

[0067] Step 31, obtaining a magnetic field observation vector formed by at least one observation point on the reference sphere model after the magnetic field changes;

[0068] Step 32: If the magnitude of the magnetic field observation vector and the first geomagnetic radius satisfy a preset quantitative relationship, then it is determined that a weak magnetic source exists in the non-magnetic cavity, and an existence signal is output.

[0069] The reference sphere model represents the geomagnetic field and has a first geomagnetic radius.

[0070] Figure 9 The diagram shows a partial schematic of the magnetic field distribution formed after implementing the aforementioned weak magnetic field detection method in a specific application scenario. Specifically, the magnetic field distribution is mainly composed of a reference spherical model 4, which is shaped like a "spherical shell" (the area of ​​the arc-shaped solid line and two arc-shaped dashed lines in the figure) and is composed of the endpoints of multiple magnetic field vectors. The starting point of the magnetic field vectors is the center 40 of the reference spherical model 4.

[0071] Using the first observation point 41 on the reference sphere model as the aforementioned observation point, different relative positional changes with the reference sphere model 4 may occur at different times (the previous moment or any moment after the previous moment) or under different states (which could be changes in the attitude of the onboard detection device or magnetic sensor, or changes in the operating state of the onboard detection device). For example, in one case, the first observation point 41 moves to the position of the second observation point 42 and moves outward from the coverage area of ​​the reference sphere model 4; in another case, the first observation point 41 moves to the position of the third observation point 43 and moves inward from the coverage area of ​​the reference sphere model 4; in yet another case, the first observation point 41 moves to the position of the fourth observation point 44 and undergoes a relative positional change within the coverage area of ​​the reference sphere model 4.

[0072] The first geomagnetic radius can be the distance between the center of the sphere 40 and the solid arc line, i.e., R shown in the figure. The solid arc line is located between the two dashed arc lines and has a relatively balanced distance relative to the center of the sphere 40. Based on this, at this time, by judging the magnitude of the magnetic field observation vector formed after the magnetic field change at the observation point and the quantitative relationship with the first geomagnetic radius, it can be determined whether the observation point has a large fluctuation amplitude, causing it to break away from the spherical shell formed by the two dashed arc lines.

[0073] For example, in its initial state, the first observation point 41 forms a first observation vector 410 with the center of the sphere 40. When the first observation point 41 moves to the position of the second observation point 42 due to the influence of a change in the magnetic field, it forms a second observation vector 420 with the center of the sphere 40. When the first observation point 41 moves to the position of the third observation point 43 due to another change in the magnetic field, it forms a third observation vector 430 with the center of the sphere 40. When the first observation point 41 moves to the position of the fourth observation point 44 due to yet another change in the magnetic field, it forms a fourth observation vector 440 with the center of the sphere 40. Thus, the magnitude of the second observation vector 420 can be compared with the quantitative relationship between the first geomagnetic radius R, thereby determining the movement of the observation point due to changes in the magnetic field.

[0074] For example, in one embodiment, when the first observation point 41 moves to the position of the second observation point 42 or to the position of the third observation point 43, it is determined that there is a weak magnetic source outside that causes the observation point to leave the reference sphere model 4. When the first observation point 41 moves to the position of the fourth observation point 44, it is determined that there is no weak magnetic source outside that causes the observation point to leave the reference sphere model 4.

[0075] like Figure 10 As shown, another embodiment of the present invention provides a weak magnetic field detection method, specifically defining the content of the preset quantitative relationship in the previous embodiment, specifically including:

[0076] Step 31: Obtain the magnetic field observation vector formed by at least one observation point on the reference sphere model after the magnetic field changes;

[0077] Step 32': If the magnitude of the magnetic field observation vector is less than the first criterion value, or the magnitude of the magnetic field observation vector is greater than the second criterion value, then it is determined that a weak magnetic source exists in the non-magnetic cavity, and an existence signal is output.

[0078] The reference sphere model represents the geomagnetic field and has a first geomagnetic radius. The first criterion value is equal to the difference between the first geomagnetic radius and a first tolerance, and the second criterion value is equal to the sum of the first geomagnetic radius and the first tolerance. The first tolerance represents the difference between the magnitudes of different geomagnetic field vectors in the reference sphere model.

[0079] The refined step 32' can be applied to any of the above technical solutions, and in particular, to any of the above definitions of the preset quantitative relationship. Based on this, the magnetic field observation vector before the magnetic field change is defined as B′. s Define the first geomagnetic radius R = |B e |, define the first tolerance as r T Then the above judgment process is as follows: if |B′ s |<|B e |-rT or |B′ s |>|B e |+r T If the signal is detected, a weak magnetic source is determined to exist within the non-magnetic cavity, and a signal is output. This utilizes the characteristic that the observation points are typically uniformly distributed within the spherical shell of the reference spherical model 4, ensuring that the above judgment steps are sufficient to cover most cases of observation point selection and making the output results more accurate.

[0080] Among them, B e This can characterize the geomagnetic field vector detected in a space excluding weak magnetic sources, and is preferably a calibrated geomagnetic field vector. In some embodiments, the magnitude of this geomagnetic field vector, or geomagnetic field strength, can be the square root of the sum of the squares of the orthogonal components of the geomagnetic field in the three directions, i.e. First tolerance r T The noise level of different magnetic sensors may be estimated through actual measurements, and may be based on inherent differences in their hardware construction. Therefore, different magnetic sensors may have different first tolerances r. T Regardless of whether the magnetic sensor has undergone uniform calibration for sensitivity and bias.

[0081] like Figure 11 As shown, a first embodiment of the weak magnetic field detection method according to an embodiment of the present invention is provided, specifically including:

[0082] Step 31: Obtain the magnetic field observation vector formed by at least one observation point on the reference sphere model after the magnetic field changes;

[0083] Step 32: If the magnitude of the magnetic field observation vector and the first geomagnetic radius satisfy a preset quantitative relationship, then it is determined that a weak magnetic source exists in the non-magnetic cavity, and an existence signal is output.

[0084] Step 331: Receive presence signals and obtain the number and / or average duration of presence signals;

[0085] Step 332: If the number of signals and / or the average duration are greater than a preset value, an alarm signal is output.

[0086] In the implementation where steps 31 and 32 are configured to be continuously executed, the output of the presence signal is insufficient to be used as sufficient evidence to determine the presence of a weak magnetic source in a non-magnetic cavity under high precision requirements. Therefore, in this first embodiment, at least one of the quantity of presence signals and the duration of presence signal output is determined.

[0087] Furthermore, the number of presence signals is preferably defined as the number of magnetic sensors that output presence signals. This allows for a comprehensive assessment of the presence of a weak magnetic source by combining the outputs of multiple magnetic sensors, improving the robustness of the detection process and reducing the probability of false triggering. Simultaneously, the duration is preferably defined as the average duration, which can be the arithmetic mean of multiple durations output by a single magnetic sensor under different detection cycles, or the arithmetic mean or weighted average of multiple durations output by multiple magnetic sensors under the same detection cycle. This avoids accidental alarms caused by excessive movement or other interference. Preferably, the preset value for the number of presence signals can be 2, and the preset value for the duration can be 0.5s. It is worth noting that the joint judgment and window monitoring judgment described above can be adaptively configured with the above steps.

[0088] like Figure 12 The diagram illustrates the signal changes output by the sensing unit 1120 and the alarm lamp 1111. The sensing unit 1120 can output a high-level presence signal sig(e) and a low-level absence signal sig(n). The alarm lamp 1111 or its front-end components can respectively receive or output a high-level alarm signal sig(w) and a low-level non-alarm signal sig(r). Thus, in... Figure 12 In the diagram, the dashed box represents the average duration (or the monitoring window used to detect the average duration). If the monitoring window always includes only the presence signal sig(e), then the weak magnetic source is determined to exist. After the duration of the monitoring window ends, an alarm signal is output and the alarm light 1111 is triggered to form an alarm indication.

[0089] Of course, to improve response speed, the sampling rate of the detection device can be adaptively increased, and the monitoring window duration can be shortened (i.e., the preset value for the average duration can be shortened). A suitable preset value can be selected based on stable filtered noise; this can be adaptively configured as needed. Meanwhile, the presence of a signal does not necessarily mean it will not trigger any indication. In one embodiment, the detection device is configured to generate a pre-alarm in response to the presence signal to prompt the operator to perform a detailed scan at the current location. The same steps described above can also be configured for normal alarm operation.

[0090] like Figure 13 As shown, a second embodiment of the weak magnetic field detection method according to an embodiment of the present invention is provided, specifically including:

[0091] Step 31: Obtain the magnetic field observation vector formed by at least one observation point on the reference sphere model after the magnetic field changes;

[0092] Step 32: If the magnitude of the magnetic field observation vector and the first geomagnetic radius satisfy a preset quantitative relationship, then it is determined that a weak magnetic source exists in the non-magnetic cavity, and an existence signal is output.

[0093] Step 341: Receive the presence signal and acquire the magnitude of several magnetic field observation vectors within a preset time range;

[0094] Step 342: Calculate the standard deviation of the magnitudes of several magnetic field observation vectors to obtain the magnetic observation standard deviation;

[0095] Step 343: When the standard deviation of magnetic observation is less than or equal to the preset dynamic magnetic field threshold, an alarm signal is output.

[0096] In this second embodiment, a scheme corresponding to the dynamic judgment described above is provided. By calculating the standard deviation, it is determined whether the detection device is in rapid and intense motion, thereby eliminating false alarms and other interference caused by changes in the magnetic field. The modulus of the plurality of magnetic field observation vectors can be the modulus of multiple magnetic field observation vectors formed by a single magnetic sensor within a preset time range. The data length is defined as L. m (or the magnitude of several magnetic field observation vectors formed within a preset time range), the magnitude of the magnetic field observation vector is defined as the sensing axis j of the magnetic sensor, where the sensing axis j can be any one of the x-axis, y-axis, or z-axis, then the standard deviation of magnetic observation std mag It can be configured to at least satisfy:

[0097] std mag =std(mag(L m ,j));

[0098] Here, mag() represents the data detected by any magnetic sensor, and std() represents the standard deviation of the data sequence. Therefore, when the standard deviation of magnetic observation is std(), the standard deviation of the data sequence is calculated. mag Satisfy std mag std mTh If the current detection device is determined to be in a violently moving or rapidly changing magnetic field, and the presence of a weak magnetic source cannot be determined based on the current results, the operator can be instructed to shut down the detection device for self-protection; when the magnetic observation standard deviation std mag Satisfy std mag ≤std mTh When the current detection device is determined to be working normally, an alarm signal can be output corresponding to the presence signal output in the aforementioned steps; where std mTh The dynamic magnetic field threshold is denoted as .

[0099] like Figure 14 As shown, a third embodiment of the weak magnetic field detection method according to an embodiment of the present invention is provided, specifically including:

[0100] Step 31': Obtain the magnetic field observation vector formed by at least one observation point on the reference sphere model after the magnetic field changes, as well as the acceleration and rotational angular velocity change signals during the magnetic field change process, to obtain the magnitude, acceleration data and gyroscope data of the magnetic field observation vector;

[0101] Step 32: If the magnitude of the magnetic field observation vector and the first geomagnetic radius satisfy a preset quantitative relationship, then it is determined that there is a weak magnetic source in the non-magnetic cavity, and an existence signal is output.

[0102] Step 351: Receive the presence signal, calculate the standard deviation of the acceleration data and / or the average value of the gyroscope data, and obtain the velocity standard deviation and / or the gyroscope mean.

[0103] Step 352: If the speed standard deviation is less than or equal to the preset dynamic speed threshold, and / or when the gyroscope mean is less than or equal to the preset dynamic rotation threshold, then an alarm signal is output.

[0104] In this third embodiment, another scheme corresponding to the dynamic judgment described above is provided. By receiving and calculating at least one of acceleration data and gyroscope data (or specifically, calculating the standard deviation of the acceleration data and the average value of the gyroscope data), it is determined whether the detection device is in rapid and intense motion, thereby eliminating false alarms and other interference caused by the resulting magnetic field changes. Based on this, the above-mentioned detection device or other devices equipped with the weak magnetic field detection method provided in this embodiment can be further configured with an acceleration sensor and / or a gyroscope. Of course, one of the above components can be set in the detection device, or multiple components can be integrated into each sensing element and arranged as a whole.

[0105] Define the data length as L m (Or acceleration data generated within a preset time range), the sensing axis of the magnetic sensor corresponding to the acceleration data is defined as j, where the sensing axis j can be any one of the x-axis, y-axis, or z-axis, then the velocity standard deviation std acc It can be configured to at least satisfy:

[0106] std acc =std(acc(L m ,j));

[0107] Here, acc() represents the data detected by any accelerometer, and std() calculates the standard deviation of the data sequence. Therefore, when the velocity standard deviation is std... acc Satisfy std acc std aTh If the current detection device is determined to be in a violently moving or rapidly changing magnetic field, and the presence of a weak magnetic source cannot be determined based on the current results, the operator can be instructed to shut down the detection device for self-protection; when the velocity standard deviation std accSatisfy std acc ≤std aTh When the current detection device is determined to be working normally, an alarm signal can be output corresponding to the presence signal output in the aforementioned steps; where std aTh The dynamic speed threshold is defined as follows.

[0108] Correspondingly, the data length is defined as L. m (Or, the gyroscope data generated within a preset time range), the sensing axis of the magnetic sensor corresponding to the gyroscope data is defined as j, where the sensing axis j can be any one of the x-axis, y-axis, or z-axis, then the gyroscope mean A gyr It can be configured to at least satisfy:

[0109] A gyr =mean(gyr(L) m ,j));

[0110] Here, gyr() represents the data detected by any gyroscope, and mean() represents the average value of the data sequence. Therefore, when the gyroscope mean A... gyr Satisfy A gyr >A gTh If the current detection device is determined to be in a violently moving or rapidly changing magnetic field, and the presence of a weak magnetic source cannot be determined based on the current results, the operator can be instructed to shut down the detection device for self-protection; when the gyroscope average value A gyr Satisfy A gyr ≤A gTh When the current detection device is determined to be working normally, an alarm signal can be output corresponding to the presence signal output in the aforementioned steps; where A gTh The dynamic rotation threshold is defined as follows.

[0111] The reason for calculating the standard deviation and the average value separately is that the detection device also experiences acceleration during normal use, so calculating the standard deviation allows us to understand the changes in acceleration. However, the angle changes during normal use are often insignificant or even zero, so calculating the average value allows us to quickly understand the current changes. Those skilled in the art can derive more implementation methods based on this principle.

[0112] It should be noted that although the above three embodiments provide different steps set after the presence of a signal for determining whether an alarm should be triggered, this does not mean that the different embodiments are necessarily isolated from each other. To avoid redundancy, this document will not elaborate too much on the combination of the above three embodiments, but it is understandable that in other embodiments, the output of the alarm signal can be configured to achieve the desired result when any two, three, or more of the quantity requirements, duration requirements, standard deviation requirements, acceleration requirements, and gyroscope data requirements are met, thereby introducing mechanisms such as joint judgment, window monitoring, and dynamic judgment to further reduce the probability of false triggering. In one embodiment, the execution can proceed in the order of executing the third embodiment first and then the first embodiment, or in the order of executing the second embodiment first and then the first embodiment, or in the order of executing the second and third embodiments simultaneously, followed by the first embodiment. This forms a judgment logic of "data reception—data correction—dynamic judgment—data analysis—joint judgment—window monitoring judgment".

[0113] like Figure 15 As shown, another embodiment of the present invention provides a weak magnetic field detection method, which adds several preliminary steps before performing weak magnetic field detection, specifically including:

[0114] Step 301: Obtain geomagnetic field data from multiple directions and fit a reference sphere model in a three-dimensional coordinate system;

[0115] Step 302: Calculate the geomagnetic field vectors from multiple directions based on the geomagnetic field data;

[0116] Step 303: Calculate the first tolerance based on the magnitude of the geomagnetic field vector;

[0117] Step 31: Obtain the magnetic field observation vector formed by at least one observation point on the reference sphere model after the magnetic field changes;

[0118] Step 32: If the magnitude of the magnetic field observation vector and the first geomagnetic radius satisfy a preset quantitative relationship, then it is determined that a weak magnetic source exists in the non-magnetic cavity, and an existence signal is output.

[0119] The reference sphere model represents the geomagnetic field and has a first geomagnetic radius. The first tolerance represents the difference between the magnitudes of different geomagnetic field vectors in the reference sphere model. The geomagnetic field vector can be configured as a directed line segment pointing from the center of the reference sphere model to the position of the geomagnetic field data in a three-dimensional coordinate system. The first tolerance can be configured as an integer multiple of the standard deviation of the magnitude of the geomagnetic field vector.

[0120] The tracking of the observation point and the acquisition and judgment of the magnitude of the magnetic field observation vector need to be based on a reference sphere model. The reference sphere model can be preset before the detection. It should usually be formed by fitting the geomagnetic field data completely without the presence of a weak magnetic source. Of course, under other special conditions, such as when the detection environment requires an external constant magnetic field, the reference sphere model can be formed by fitting the external magnetic field and the geomagnetic field together.

[0121] The fitting of the reference sphere model relies on geomagnetic field data from multiple directions. Since the geomagnetic field data is relative to the Earth coordinate system, this raw geomagnetic field data (or, as mentioned earlier, the geomagnetic field vector) can be defined as B. e (The value can be in the range of 50-60 μT), and it needs to be converted into a representation in a three-dimensional coordinate system fitted relative to the detection device. This type of geomagnetic field data can be defined as B. s Based on this, geomagnetic field data B was detected. s It can be configured to at least satisfy:

[0122] B s =R es B e ;

[0123] Among them, R es This is the transformation matrix. Since the Earth's magnetic field is uniform and stable, and the orientation of the detection device can be adjusted, the projection of the geomagnetic field onto each axis at various parts of the device (or at each of its magnetic sensors) varies. Therefore, under certain operating conditions, it can rotate in an open environment without additional magnetic field interference to obtain multi-directional geomagnetic field data, and based on the data measured at each time t:

[0124] B s (t)=[B x (t),B y (t),B z (t)],

[0125] The detected geomagnetic field data is plotted in a three-dimensional coordinate system to fit and form a reference spherical model. Of course, there are many other ways to fit the geomagnetic field data into the reference spherical model; this invention is not limited to fitting the data based on the vector corresponding to the geomagnetic field data. In one case, the geomagnetic field data can also be defined as the coordinates of the corresponding geomagnetic field vector, which can also achieve the expected technical effect of step 301.

[0126] This embodiment further provides a technical solution for calculating the first tolerance of the reference sphere model based on the magnitude of the geomagnetic field vector. This can be achieved by calculating the difference between the maximum and minimum magnitudes of the geomagnetic field vectors from multiple directions as the first tolerance; alternatively, it can be achieved by calculating the standard deviation of the magnitudes of all geomagnetic field vectors and directly using this standard deviation as the first tolerance; or by performing a multiplication operation on the standard deviation to use it as the first tolerance (increasing the tolerance and improving the model's error tolerance). In one embodiment, the first tolerance is defined as r. T Then at least the configuration must satisfy:

[0127] r Ti =n·std({|B si |} 1,2,...,M );

[0128] Where std() is the standard deviation calculation function, {|B si |} 1,2,...,M Let be the magnitude of the M geomagnetic field vectors measured by the i-th magnetic sensor, where n is an empirical multiple, and the value of can be in the range of 1-3.

[0129] Furthermore, in another embodiment, step 303 may specifically include: analyzing the magnitude of the geomagnetic field vector, filtering out outliers, and calculating the first tolerance of the reference sphere model based on the magnitude of the filtered geomagnetic field vector. This further improves the accuracy of the model fitting.

[0130] like Figure 16 As shown, a specific example of a weak magnetic field detection method in another embodiment of the present invention is provided, which specifically includes:

[0131] Step 3011: Obtain geomagnetic field data from multiple magnetic sensors in multiple orientations, fit multiple spherical models in a three-dimensional coordinate system, and obtain multiple calibration spherical models.

[0132] Step 3012: Calculate the center of the calibrated sphere model and the vector from the center of the sphere to the calibration point to obtain multiple calibration vectors for the calibrated sphere centers;

[0133] Step 3013: Using one of the calibration vectors of multiple calibration sphere models, calibrate the modulus of multiple calibration vectors to obtain multiple data vectors;

[0134] Step 3014: Calculate multiple data points based on the data vector and the corresponding calibration sphere center, and fit the reference sphere model in the three-dimensional coordinate system based on the data points;

[0135] Step 31: Obtain the magnetic field observation vector formed by at least one observation point on the reference sphere model after the magnetic field changes;

[0136] Step 32: If the magnitude of the magnetic field observation vector and the first geomagnetic radius satisfy a preset quantitative relationship, then it is determined that a weak magnetic source exists in the non-magnetic cavity, and an existence signal is output.

[0137] The magnetic field data is distributed on the calibration sphere model to form multiple calibration points; the calibration vector is one of the calibration vectors of the calibration sphere model in a preset direction.

[0138] Since actual magnetic sensors often exhibit some inconsistencies, this specific example provides a refined approach to step 301 to further improve detection accuracy and the quality of the reference sphere model. It is worth noting that although steps 302 and 303 are omitted in this embodiment, this does not mean that this embodiment cannot combine the above steps to form a new technical solution.

[0139] Define the magnetic field value measured by the i-th sensor on the j-axis in the detection device as B. ij Then it can be configured to at least satisfy:

[0140]

[0141] in, Let be the unit vector in the positive direction of the j-axis. K represents the projection of the Earth's magnetic field onto the sensor's j-axis. ij D is the conversion coefficient of sensor i on the j-axis, with an ideal value of 1, meaning the output equals the input; ij This is the bias.

[0142] Because magnetic sensors are affected by circuit design, manufacturing process, and temperature changes, the conversion coefficient K... ij Possibly deviating from 1, bias D ij The value may not be zero, causing errors in the magnetic field output of the magnetic sensor, and the output will not be zero even without an external magnetic field. This will be reflected in a three-dimensional coordinate system as follows: Figure 17 The ellipsoidal model shown, whose center is not at the origin, can be defined as a calibration sphere model 4'.

[0143] The intensity of geomagnetic field data acquired by the same magnetic sensor in different orientations will vary (which is why the calibration spherical model 4' is ellipsoidal). Based on this, geomagnetic field data from multiple orientations can be collected by changing the orientation of the magnetic sensor. After fitting this data into an ellipsoidal model, the calibration center of the current ellipsoidal model is defined as ΔB. i Then we can have:

[0144] ΔB i =[ΔB ix ,ΔB iy ,ΔB iz ];

[0145] Therefore, the offset of the calibration center of the ellipsoid model relative to the origin, at least along the x-axis, y-axis, and z-axis, can be calculated. Furthermore, because:

[0146]

[0147] Thus, the bias D can be obtained. ij And can be further determined based on the calibrated sphere center coordinates [ΔB] ix ,ΔB iy ,ΔB iz The dimensions of the calibration spherical model 4' in various directions (e.g., the major and minor axes of the ellipsoid) are obtained. Then, based on the calibration sphere center and the dimensions in each direction, different calibration vectors are calculated. One of these vectors is selected as the calibration vector, and the other calibration vectors are calibrated (either by scaling up or projecting the modulus) to finally generate a reference spherical model corresponding to the magnetic sensor. This improves the non-standard spherical model caused by the magnetic sensor's own errors, facilitating subsequent determination of the presence of a weak magnetic source using the modulus of the magnetic field observation vector.

[0148] The foregoing describes the fitting and processing of geomagnetic field data from a single sensor in multiple orientations. Therefore, steps 3011 to 3014 of this invention are not limited to the case of multiple magnetic sensors. They can also include: acquiring geomagnetic field data from the magnetic sensors in multiple orientations; fitting a spherical model in a three-dimensional coordinate system to obtain a calibration spherical model; calculating the center of the calibration spherical model and the vector from the center to the calibration point to obtain the calibration center and calibration vector; using one of the calibration vectors of the calibration spherical model as a calibration vector to calibrate the magnitudes of multiple calibration vectors to obtain multiple data vectors; calculating multiple data points based on the data vectors and the calibration center, and fitting a reference spherical model in a three-dimensional coordinate system based on the data points.

[0149] Since the major and minor axes of an ellipsoid do not necessarily extend along the x-axis, y-axis, or z-axis, the weak magnetic field detection method may further include: determining the major and / or minor axes of the calibration sphere model, using the vector containing at least one of the major or minor axes as a calibration vector, calibrating the magnitudes of other calibration vectors, and obtaining multiple data vectors.

[0150] Different magnetic sensors may have varying degrees of deviation, which can lead to differences in their output (e.g., different vector components, different total intensity, etc.), resulting in different fitted patterns. Figure 18The multiple calibration sphere models 4' shown are illustrated. Based on this, the first calibration sphere model 4A', second calibration sphere model 4B', third calibration sphere model 4C', fourth calibration sphere model 4D', fifth calibration sphere model 4E', sixth calibration sphere model 4F', and seventh calibration sphere model 4G' in the calibration sphere model 4' can be fitted. It is worth noting that the above multiple calibration sphere models can be generated by fitting the geomagnetic field data corresponding to multiple magnetic sensors, respectively.

[0151] The first calibration sphere model 4A' is defined as being formed by fitting the geomagnetic field data obtained from the first magnetic sensor. Assuming that its vector extending along the positive x-axis is used as the calibration vector, the magnitude of this calibration vector is r. 1x The magnitude of the calibrated quantity of the i-th magnetic sensor on the j-th axis is r. ij Furthermore, the modulus r of the calibration vector can be adjusted. 1x The modulus of other calibrated quantities ij Perform scalar operations to calibrate other calibrated quantities and form corresponding calibrated data vectors.

[0152] The above process transforms multiple calibration spherical models, shaped like ellipsoids and located at different positions, into multiple spherical models, approximately spheres, located at different positions. Furthermore, the calibration process can also include an offset D. ij The participation of [unclear] is used to unify the calibration centers of different calibrated spheres to the origin of the three-dimensional coordinate system (calibration vector minus the corresponding offset D). ij Or ΔB ij ),thereby Figure 18 After traversing and processing multiple calibration sphere models, they will eventually be uniformly fitted to form a model like... Figure 19 The reference sphere model 4 shown has geomagnetic field data detected by different magnetic sensors distributed on it, which is sufficient to adapt to the subsequent steps of the weak magnetic field detection method provided above, and uses the magnetic field change at the observation point as an indicator to determine whether weak magnetic field exists.

[0153] The above steps improve the consistency of detection data from different magnetic sensors in the detection device, as well as the consistency of detection data from different axes of the same magnetic sensor.

[0154] like Figure 20 The image shows a first embodiment of a specific example of a weak magnetic field detection method in another embodiment of the present invention, which specifically includes:

[0155] Step 3011: Obtain geomagnetic field data from multiple magnetic sensors in multiple orientations, fit multiple spherical models in a three-dimensional coordinate system, and obtain multiple calibration spherical models.

[0156] Step 3012: Calculate the center of the calibrated sphere model and the vector from the center of the sphere to the calibration point to obtain multiple calibration sphere centers and calibration vectors;

[0157] Step 3013: Using one of the calibration vectors of multiple calibration sphere models, calibrate the modulus of multiple calibration vectors to obtain multiple data vectors;

[0158] Step 3014: Calculate multiple data points based on the data vector and the corresponding calibration sphere center, and fit the reference sphere model in the three-dimensional coordinate system based on the data points;

[0159] Step 311: Obtain the vector corresponding to the observation point in the first state to obtain the first observation vector;

[0160] Step 312: Obtain the vector corresponding to the observation point in the second state, and calibrate it with the calibration vector to obtain the second observation vector;

[0161] Step 32”: If the magnitude of the second observation vector and the first geomagnetic radius satisfy a preset quantitative relationship, then it is determined that there is a weak magnetic source in the non-magnetic cavity, and an existence signal is output.

[0162] The first embodiment provides a detailed step 31 that complements the aforementioned steps, and a corresponding step 32, wherein the first observation vector can correspond to Figure 9 The first observation vector in the vector is 410, and the second observation vector can correspond to... Figure 9 The second observation vector 420, the third observation vector 430, and the fourth observation vector 440, or any other observation vector that has changed relative to the first observation vector 410.

[0163] Although steps 301 and 31 are configured in detail simultaneously in this embodiment, the only relationship between them is that step 31 relies on the calibration parameters generated in step 301. It is understandable that step 301 can be implemented independently of step 31 to generate a more accurate reference sphere model. The technical effects corresponding to the specific implementation provided in step 31 can, of course, replace other implementation methods described above.

[0164] like Figure 21 The image shows a second embodiment of a specific example of a weak magnetic field detection method in another embodiment of the present invention, which specifically includes:

[0165] Step 3011: Obtain geomagnetic field data from multiple magnetic sensors in multiple orientations, fit multiple spherical models in a three-dimensional coordinate system, and obtain multiple calibration spherical models.

[0166] Step 3012: Calculate the center of the calibrated sphere model and the vector from the center of the sphere to the calibration point to obtain multiple calibration sphere centers and calibration vectors;

[0167] Step 30131: Calculate multiple calibration parameters based on the calibration vector and the magnitudes of multiple calibration quantities;

[0168] Step 30132: Based on multiple calibration parameters, calibrate the magnitudes of multiple calibration quantities to obtain multiple data vectors;

[0169] Step 3014: Calculate multiple data points based on the data vector and the corresponding calibration sphere center, and fit the reference sphere model in the three-dimensional coordinate system based on the data points;

[0170] Step 311: Obtain the vector corresponding to the observation point in the first state to obtain the first observation vector;

[0171] Step 3121: Obtain the calibration parameters corresponding to the first observation vector to obtain the observation calibration parameters;

[0172] Step 3122: Obtain the vector corresponding to the observation point in the second state, calibrate with the observation calibration parameters, and obtain the second observation vector;

[0173] Step 32”: If the magnitude of the second magnetic field observation vector and the first geomagnetic radius satisfy a preset quantitative relationship, then it is determined that there is a weak magnetic source in the non-magnetic cavity, and an existence signal is output.

[0174] Wherein, the calibration parameter is the quotient of the modulus of the calibration vector and the modulus of the calibration quantity.

[0175] Define the magnitude of the calibration vector as r 1x The magnitude of the calibration quantity of the i-th sensor on the j-th axis is r. ij Then the calibration parameter s corresponding to the calibrated quantity ij-1x At least the following configuration is required:

[0176]

[0177] This allows us to calculate the scaling factor required to correct the magnitude of the calibration quantity to the calibration vector, thus unifying the different conversion factors and ultimately making it sufficient to fit a reference sphere model similar to a perfect sphere. The conversion factor K corresponding to sensor i on the j-axis is... ij Then we have:

[0178] K′ ij =s ij-1x K ij ≈K 1x ;

[0179] Wherein, K′ ij K is the data vector corresponding to the calibration vector. 1xThe conversion coefficient is the one corresponding to the calibration vector (in this embodiment, it is the conversion coefficient corresponding to the calibration vector of the first magnetic sensor in the x-axis direction).

[0180] Based on this, in embodiments where multiple magnetic sensors are configured in the detection device, calibration parameters s can be utilized. ij-1x The calibration vectors of all magnetic sensors are calibrated in all axes to generate the data vector B′. ij , where data vector B′ ij At least the following configurations must be met:

[0181] B′ ij =s ij-1x (B ij -ΔB ij );

[0182] Among them, B ij For the output of the i-th magnetic sensor on the j-th axis, ΔB ij This is the bias on the j-axis corresponding to the i-th magnetic sensor.

[0183] Although steps 3013 and 312 are configured in detail simultaneously in this embodiment, the only relationship between them is that step 312 relies on the calibration parameters generated in step 3013. It is understandable that step 3013 can be implemented independently of step 312 to generate a more accurate reference sphere model. The technical effects corresponding to the specific implementation provided in step 31 can, of course, replace other implementation methods described above.

[0184] The above calibration process can be performed during any phase of the detection process.

[0185] For example, during operation, the detection device calculates the magnetic field strength in real time and identifies weak magnetic sources. If a magnetic sensor's measurement value approaches its range, a status light can indicate to the operator that strong magnetic interference (such as from a magnetic control system or a large magnet) is present, affecting the device's operation. In this case, the alarm light can be configured to remain off to prevent false alarms. The operator can then recalibrate the detection device after avoiding the magnetic interference. Once calibration is complete and the interference has been eliminated, the alarm light and detection process can be restarted.

[0186] For example, when the detection device is started and initialized, or when it needs to be restarted and recalibrated due to a strong magnetic field impact, the operator can place the detection device in an environment without a significant magnetic field, or randomly shake it in that environment (either by drawing circles in a figure-eight pattern or by rotating the detection device) until all calibration points are within the corresponding spherical shell area. Experiments have shown that the above initialization process typically takes 1-3 seconds.

[0187] Of course, the present invention can also provide, for example Figures 22 to 24 Another implementation method specifically includes: tracking the change in the distance between at least two observation points on the reference sphere model as the magnetic field changes, and obtaining the distance change value; if the distance change value and a preset distance change threshold satisfy a preset quantitative relationship, then it is determined that a weak magnetic source exists in the non-magnetic cavity. This can prevent situations where the magnetic field generated by the weak magnetic source is insufficient to detach the observation point from the geomagnetic field sphere, leading to missed detections or omissions.

[0188] like Figure 22 As shown, the reference sphere model may include a fifth observation point 45 and a sixth observation point 46, which have a first distance Δx1 in the initial state and correspond to the sphere center 40 to form a fifth observation vector 450 and a sixth observation vector 460, respectively. After the external magnetic field of the detection device changes, the fifth observation point 45 moves to the first position 45' and forms a new observation vector 450' with the sphere center 40. The sixth observation point 46 moves to the second position 46' and forms another new observation vector 460' with the sphere center 40. The first position 45' and the sixth position 46' have a second distance Δx2.

[0189] Based on this, the difference between the first and second spacings can be calculated to obtain the spacing change value, and a quantitative relationship can be determined with the corresponding spacing change threshold to determine whether a weak magnetic source exists within the non-magnetic cavity. This technical solution can be used as a standalone method to determine the presence of a weak magnetic source, or as a supplement to the aforementioned method of using the magnitude of the magnetic field observation vector to determine the presence of a weak magnetic source. That is, if the magnitude of the magnetic field observation vector does not satisfy a preset quantitative relationship with the first geomagnetic radius, the above steps are performed for further verification and judgment.

[0190] Furthermore, in another embodiment, the weak magnetic field detection method may further include: tracking the dispersion of at least two sets of observation points on a reference sphere model to obtain first dispersion data and second dispersion data, and tracking the overall dispersion of the at least two sets of observation points to obtain global dispersion data, which are respectively used to characterize the change of the distance between observation points with the magnetic field; if the global dispersion data and the distance change threshold, the first dispersion data and the second dispersion data satisfy a preset quantitative relationship, then it is determined that a weak magnetic source exists in the non-magnetic cavity.

[0191] Preferably, the first dispersion data is defined as s(group1), the second dispersion data is defined as s(group2), and the spacing variation threshold (or dispersion tolerance) is defined as s. th If the global discrete data is defined as s(group1,group2,...), then the global discrete data must be configured to at least satisfy the following:

[0192] s(group1,group2,...)>max(s(group1),s(group1),...)+s th .

[0193] That is, if the global discrete data is greater than the sum of the maximum value among all discrete data, including the first and second discrete data, and the discrete tolerance, it is determined that the magnetic field as a whole has been disturbed by an external magnetic field (such as a weak magnetic source), and therefore a weak magnetic source is determined to exist within the non-magnetic cavity. In this embodiment, even if errors occur that lead to outliers inside, the above conditions will not be triggered, preventing the system from making a misjudgment. The discrete tolerance serves to adjust the sensitivity and anti-interference capability of the calculation and judgment.

[0194] If the global discrete data are approximately equal to or slightly smaller than the sum of the maximum value and the dispersion tolerance, it is determined that the overall magnetic field is not disturbed by an external magnetic field. This condition still holds even in the presence of outliers.

[0195] Similar to the aforementioned technical solutions, the preferred technical solutions provided by this invention can serve as supplementary verification steps to any of the aforementioned embodiments. They can also serve as independent methods for determining weak magnetic sources, replacing the aforementioned technical solution of determining the presence of a weak magnetic source by observing the magnitude of the magnetic field vector, and are preferably combined with any of the additional features or embodiments described above.

[0196] Specifically, such as Figure 23 As shown, for a single set of observation points, the set of observation points before the magnetic field change is defined as being distributed in the first region 47, which has a certain degree of dispersion. After the magnetic field change, if the set of observation points shows an increase in the dispersion data, the original set of observation points forms a first subset 471 and a second subset 472, which is reflected as the first region 47 expanding into the second region 47'. In this way, it can be determined that a weak magnetic source exists within the non-magnetic cavity.

[0197] like Figure 24 As shown, for the two sets of observation points, the third region 48A illustrates the global distribution of the first set of observation points 481A and the second set of observation points 482A under the influence of a weak magnetic source. The global distribution includes the global dispersion data. The first set of observation points 481A has first dispersion data, and the second set of observation points 482A has second dispersion data. At this point, the global dispersion data is greater than the sum of the maximum value and the dispersion tolerance in the first and second sets of dispersion data.

[0198] Region 48B shows the global distribution of the first observation point set 481B and the second observation point set 482B under another condition, which has a different degree of global dispersion. In this case, the distribution area of ​​the second observation point set 482B remains basically unchanged, and outliers appear in the first observation point set 481B. However, because the global dispersion of the fourth region 48B is approximately equal to the sum of the first dispersion of the larger first observation point set 481B and the dispersion tolerance, it can still be determined that there is no weak magnetic source or other external magnetic field influence at this time, so the influence of outliers can be better eliminated.

[0199] Of course, the method provided in this embodiment may further include: filtering out outliers from the at least two observation points after the change, and calculating the dispersion data based on the filtered observation points.

[0200] In summary, this invention utilizes the weak magnetism carried by medical devices to detect medical devices within non-magnetic cavities. By fitting a reference sphere model characterizing the strength of the Earth's magnetic field, it tracks the vector changes of a data point within this reference sphere model under different states, and then compares and judges based on certain preset quantitative relationships. Since the detection process only needs to receive the Earth's magnetic field and the weak magnetic field emitted by the medical device, and does not send signals to the non-magnetic cavity, it will not generate high-intensity radiation that could damage the non-magnetic cavity. At the same time, the technical solution based on fitting a sphere model and performing vector judgment achieves the technical effects of fast detection speed, simple process, and low probability of false triggering.

[0201] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0202] The detailed descriptions listed above are merely specific descriptions of feasible embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method of detecting a weakly magnetic medical device within a non-magnetic cavity, the method comprising: applying a magnetic field to the cavity; detecting a magnetic field generated by the medical device; and determining a strength of the detected magnetic field. The method comprises the following steps: acquiring a magnetic field observation vector formed by at least one observation point after a magnetic field change on a reference spherical model; wherein the reference spherical model represents a geomagnetic field condition and has a first geomagnetic radius; if a preset quantitative relationship is satisfied between a modulus of the magnetic field observation vector and the first geomagnetic radius, it is determined that a weak magnetic source exists in the non-magnetic cavity, and an existing signal is outputted; The method specifically comprises: if the modulus of the magnetic field observation vector is less than a first criterion value, or the modulus of the magnetic field observation vector is greater than a second criterion value, it is determined that a weak magnetic source exists in the non-magnetic cavity, and an existing signal is outputted; wherein the first criterion value is equal to the difference between the first geomagnetic radius and a first tolerance, the second criterion value is equal to the sum of the first geomagnetic radius and the first tolerance, and the first tolerance represents the difference between the moduli of different geomagnetic field vectors in the reference spherical model.

2. The method of field-weakening detection according to claim 1, characterized in that The method further comprises: receiving the existing signal, acquiring the number and / or average duration of the existing signal; if the number and / or average duration of the existing signal is greater than a preset value, an alarm signal is outputted.

3. The method of field-weakening detection according to claim 1, characterized in that The method further comprises: receiving the existing signal, acquiring the moduli of a plurality of magnetic field observation vectors within a preset time range; calculating the standard deviation of the moduli of the plurality of magnetic field observation vectors to obtain a magnetic observation standard deviation; when the magnetic observation standard deviation is less than or equal to a preset dynamic magnetic field threshold value, an alarm signal is outputted.

4. The method of field-weakening detection according to claim 1, characterized in that The method specifically comprises: acquiring a magnetic field observation vector formed by at least one observation point after a magnetic field change on a reference spherical model, and an acceleration and rotational angular velocity change signal during the magnetic field change, to obtain the modulus of the magnetic field observation vector, acceleration data, and gyroscopic data; The method further comprises: receiving the existing signal, calculating the standard deviation of the acceleration data, and / or the average value of the gyroscopic data, to obtain a speed standard deviation and / or a gyroscopic average value; if the speed standard deviation is less than or equal to a preset dynamic speed threshold value, and / or when the gyroscopic average value is less than or equal to a preset dynamic rotation threshold value, an alarm signal is outputted.

5. The method of field-weakening detection according to claim 1, characterized in that The method specifically comprises: acquiring multi-azimuth geomagnetic field data, and fitting the reference spherical model in a three-dimensional coordinate system; calculating a plurality of multi-azimuth geomagnetic field vectors according to the geomagnetic field data; calculating a first tolerance in the preset quantitative relationship according to the modulus of the geomagnetic field vector; wherein the first tolerance represents the difference between the moduli of different geomagnetic field vectors in the reference spherical model, the geomagnetic field vector is configured as a directed line segment from the center of the reference spherical model to the position of the geomagnetic field data in the three-dimensional coordinate system, and the first tolerance is configured as an integer multiple of the standard deviation of the modulus of the geomagnetic field vector.

6. The method of field-weakening detection according to claim 1, characterized in that The method further comprises: acquiring multi-azimuth geomagnetic field data of a plurality of magnetic sensors, fitting a plurality of spherical models in a three-dimensional coordinate system to obtain a plurality of calibrated spherical models; calculating the center of the calibrated spherical model and the vector from the center of the reference spherical model to the calibration point to obtain a plurality of calibrated center of spheres and calibration vectors; Calibrating the modulus of the plurality of calibration vectors with a calibration vector of one of the plurality of calibration sphere models to obtain a plurality of data vectors; According to the data vectors and the corresponding calibration sphere centers, a plurality of data points are calculated, and a reference sphere model is fitted in a three-dimensional coordinate system according to the data points; Wherein, the magnetic field data is distributed on the calibration sphere model to form a plurality of calibration points; the calibration vector is a calibration vector of one of the calibration sphere models in a preset direction; The method specifically comprises: Obtaining a vector corresponding to the observation point in the first state to obtain a first observation vector; Obtaining a vector corresponding to the observation point in the second state and calibrating it with the calibration vector to obtain a second observation vector; If the modulus of the second observation vector and the first geomagnetic radius satisfy a preset quantitative relationship, it is determined that the weak magnetic source exists in the non-magnetic cavity, and the existence signal is output.

7. The method of field-weakening detection according to claim 6, characterized in that The calibration sphere model is an ellipsoid, the preset direction is the long axis direction of the ellipsoid, and the method specifically comprises: According to the calibration vector and the modulus of the plurality of calibration vectors, a plurality of calibration parameters are calculated; wherein the calibration parameter is the quotient of the modulus of the calibration vector and the modulus of the calibration vector; According to a plurality of calibration parameters, the modulus of a plurality of calibration vectors is calibrated to obtain a plurality of data vectors; The method specifically comprises: Obtaining a calibration parameter corresponding to the first observation vector to obtain an observation calibration parameter; Obtaining a vector corresponding to the observation point in the second state and calibrating it with the observation calibration parameter to obtain a second observation vector.

8. The method of field-weakening detection according to claim 1, characterized in that The method further comprises: If the modulus of the magnetic field observation vector and the first geomagnetic radius do not satisfy the preset quantitative relationship, the distance change value of at least two observation points on the reference sphere model is tracked with the change of the magnetic field to obtain the distance change value; If the distance change value and the preset distance change threshold value satisfy the preset quantitative relationship, it is determined that the weak magnetic source exists in the non-magnetic cavity.

9. The method of field-weakening detection according to claim 8, characterized in that The method further comprises: Tracking the dispersion of at least two groups of observation point sets on the reference sphere model to obtain first dispersion data and second dispersion data, and tracking the dispersion of the at least two groups of observation points as a whole to obtain global dispersion data, which are respectively used to represent the distance change of the observation points with the change of the magnetic field; If the global dispersion data, the preset distance change threshold value, the first dispersion data and the second dispersion data satisfy the preset quantitative relationship, it is determined that the weak magnetic source exists in the non-magnetic cavity.

10. An endoscope probe for probing an endoscope in a human body, the endoscope being configured to have a weak magnetism, characterized by, The endoscope probe comprises a detection panel and a handle connected to the detection panel, the detection panel comprises a display surface and a sensing surface arranged opposite to each other, and the endoscope probe is configured to implement the weak magnetic detection method of any one of claims 1-9.

11. The endoscopic probe of claim 10, wherein, The display surface is provided with an alarm lamp and a state lamp configured in a ring shape, the sensing surface is uniformly provided with at least four sensing units, the sensing units comprise at least two magnetic sensors, one of the magnetic sensors is arranged on one side close to the geometric center of the sensing surface, and the other is arranged on the side away from the geometric center.

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