WO2023221283A1 - Inertial measurement-integrated magnetic control system - Google Patents

Abstract

Disclosed is an inertial measurement-integrated magnetic control system (1), comprising an instrument (10), an electromagnetic device (20), and a processing apparatus (30). The instrument (10) comprises an inertial sensor and an induction coil (13) for generating an induction signal on the basis of a variable magnetic field. The electromagnetic device (20) comprises an electromagnetic coil (22) for generates a variable magnetic field on the basis of a variable current. The induction coil (13) receives the variable magnetic field generated by the electromagnetic coil (22) and generates the induction signal. The processing apparatus (30) acquires the motion state of the instrument (10) and the relative coordinates of the instrument (10) and the electromagnetic device (20) on the basis of an inertial signal measured by the inertial sensor and the induction signal generated by the induction coil (13). The magnetic control system (1) can improve the accuracy of positioning the instrument (10).

Description

Magnetic control system integrating inertial measurement Technical field

The present disclosure generally relates to a medical device, and specifically to a magnetic control system incorporating inertial measurements.

Background technique

With the development of modern medical technology, lesions in the digestive cavity (such as polyps on the gastric wall) can be inspected by introducing a capsule endoscope, which can collect images in the stomach, such as Images of polyps in the stomach wall to help doctors diagnose patients.

At present, such capsule endoscopes usually have built-in magnets and can be affected by magnetic force. Operators such as doctors and nurses can magnetically guide the capsule endoscope located in the digestive cavity by operating an external magnetic control device so that the capsule The endoscope moves to a predetermined position in the digestive cavity to collect images. In order to guide the capsule endoscope more accurately, it is usually necessary to position the capsule endoscope. In the prior art, the capsule endoscope is usually positioned by magnetically detecting an external electromagnetic device through a magnetic sensor built into the capsule endoscope.

However, in the above-mentioned prior art, when the magnetic sensor performs magnetic detection, it may be difficult to accurately position the capsule endoscope due to the influence of environmental magnetic fields such as magnetic permeable materials of peripheral devices and the geomagnetic field.

Contents of the invention

The present disclosure is proposed in view of the above-mentioned status of the prior art, and its purpose is to provide a magnetic control system that integrates inertial measurement and can improve positioning accuracy.

To this end, the present disclosure provides a magnetic control system that integrates inertial measurement, which includes an instrument, an electromagnetic device, and a processing device. The instrument includes an inertial sensor and an induction coil that generates an induction signal based on a changing magnetic field. The electromagnetic device includes An electromagnetic coil that generates a changing magnetic field based on a changing current. The induction coil receives the changing magnetic field generated by the electromagnetic coil and generates an induction signal. The processing device fuses the inertial signal measured by the inertial sensor and the induction signal. The induction signal generated by the coil is used to obtain the motion state of the instrument and the relative coordinates of the instrument and the electromagnetic device.

In the magnetic control system involved in the present disclosure, the inertial signal of the instrument is measured through the inertial sensor and the magnetic field generated by the electromagnetic coil is measured through the induction coil, and the inertial signal and the induction signal are fused, thereby improving the resolution of the inertial signal and/or induction. The accuracy of the signal can improve the positioning accuracy of the instrument.

In addition, in the magnetic control system involved in the present disclosure, optionally, the motion state includes the acceleration of the instrument and the attitude angle of the instrument, and the induction signal is a voltage signal or a current signal.

In addition, in the magnetic control system involved in the present disclosure, optionally, the processing device optimizes the motion state based on the induction signal and the error state Kalman filter algorithm; or, the processing device optimizes the motion state based on the The inertial signal and error state Kalman filter algorithm optimize the relative coordinates. As a result, the accuracy of solving the inertial signal and/or the induction signal can be improved.

In addition, in the magnetic control system related to the present disclosure, optionally, the orientation of the inertial sensor is the same as or orthogonal to the orientation of the induction coil. As a result, the inertial signal and the induction signal can be easily fused.

In addition, in the magnetic control system involved in the present disclosure, optionally, the inertial signal and the induction signal have matching time information. As a result, the inertial signal and the induction signal can be easily fused.

In addition, in the magnetic control system involved in the present disclosure, optionally, the inertial sensor includes an accelerometer and a gyroscope. Thus, the acceleration information and posture information of the instrument can be obtained.

In addition, in the magnetic control system involved in the present disclosure, optionally, the positional relationship between the induction coil and the electromagnetic coil satisfies:

Among them, μ ₀ represents the vacuum magnetic permeability, N ₁ represents the number of turns of the electromagnetic coil, S ₁ represents the coil area of the electromagnetic coil,

represents the orientation of the electromagnetic coil, I represents the amplitude of the current of the electromagnetic coil, f represents the alternating frequency of the current of the electromagnetic coil, E represents the induction signal generated by the induction coil, and N ₂ represents the The number of turns of the induction coil, S ₂ represents the coil area of the induction coil,

Indicates the orientation of the induction coil,

Indicates the relative coordinates of the induction coil compared to the electromagnetic coil.

In addition, in the magnetic control system related to the present disclosure, optionally, the number of the electromagnetic coils is multiple. In this case, multiple induction signals are generated by multiple electromagnetic coils and the relative positions of the instrument and the electromagnetic device are obtained based on the multiple induction signals, which can help further improve the magnetic positioning accuracy.

In addition, in the magnetic control system involved in the present disclosure, optionally, the instrument further includes a built-in magnet arranged in the accommodation space, and the electromagnetic device further includes a spherical operating magnet, and the operating magnet is The built-in magnet exerts a magnetic effect to cause displacement of the instrument. This facilitates magnetic guidance of the instrument.

Furthermore, in the magnetic control system involved in the present disclosure, optionally, the operating magnet includes a permanent magnet and an electromagnet based on changing current.

According to the magnetic control system according to the present disclosure, the accuracy of positioning the instrument can be improved.

Description of the drawings

The present disclosure will now be explained in further detail only by way of example with reference to the accompanying drawings, in which:

FIG. 1 is a schematic diagram showing a scene of a magnetic control system according to an example of this embodiment.

FIG. 2A is a schematic diagram showing the instrument according to this embodiment example; FIG. 2B is a schematic structural diagram showing the image acquisition device and the induction coil of the instrument according to this embodiment example.

FIG. 3A is a schematic diagram showing an electromagnetic device involved in this embodiment example; FIG. 3B is an arrangement example showing an electromagnetic coil involved in this embodiment example.

FIG. 4 is a schematic diagram showing coordinate system conversion according to the example of this embodiment.

FIG. 5 shows the magnetic positioning method according to this embodiment.

FIG. 6 illustrates a method for optimizing positioning results by combining inertial sensors according to this embodiment.

Detailed ways

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the drawings. In the following description, the same components are assigned the same reference numerals, and repeated descriptions are omitted. In addition, the drawings are only schematic diagrams, and the dimensional ratios of components, shapes of components, etc. may be different from actual ones.

It should be noted that the terms "comprising" and "having" and any variations thereof in this disclosure, such as a series of steps or units of process, method, system, product or equipment included or included, are not necessarily limited to those explicitly listed. Those steps or elements may be included or have other steps or elements not expressly listed or inherent to such processes, methods, products or apparatuses.

The magnetic control system involved in this embodiment may be a medical magnetic control system that places an instrument in a tissue cavity to inspect and/or treat the tissue cavity. The magnetic control system involved in this embodiment may also be a system that places instruments in a certain space to collect information in the space.

The medical magnetic control system involved in this embodiment may refer to a gastric examination/treatment system, intestinal examination/treatment system, etc., for example, a capsule-type instrument is placed in the digestive cavity such as the stomach, intestine, etc., to collect images through image acquisition, electrolysis, etc. Pathological information can be obtained in the digestive cavity through chemical reactions or other methods, or lesions can be treated in the digestive cavity through vibration, electrical stimulation, drug release, etc. Normally, when using such a magnetic control system to inspect the digestive cavity, the instrument needs to be guided to adjust its position within the digestive cavity.

The magnet control system according to this embodiment will be described in detail below, taking a capsule endoscope system that collects images to inspect tissue cavities as an example.

It should be noted that the “capsule endoscope” referred to herein is a specific example of the device according to this embodiment, and is not limiting. Those skilled in the art can understand that the medical device involved in this embodiment can also be, for example, a vibration capsule, an electrical stimulation capsule, an electrochemical capsule, a drug release capsule, etc., which can be placed in a tissue cavity for examination and/or treatment. equipment.

FIG. 1 is a schematic diagram showing a magnet control system (hereinafter referred to as a “capsule endoscope system”) 1 according to an example of this embodiment. In this embodiment, as shown in FIG. 1 , the capsule endoscope system 1 may include an instrument (hereinafter, referred to as a “capsule endoscope”) 10 and an electromagnetic device 20 . The capsule endoscope 10 can be placed in the tissue cavity of the subject (see FIG. 1 ), and the electromagnetic device 20 can guide the capsule endoscope 10 to move in the tissue cavity by, for example, applying magnetic effects to the instrument.

In some examples, the tissue cavity introduced by the capsule endoscope 10 may be a digestive cavity, such as the gastric cavity, esophagus, large intestine, colon, small intestine, etc. In other examples, the tissue cavity introduced by the capsule endoscope 10 may also be a non-digestive cavity, such as the abdominal cavity, chest cavity, etc. For the digestive cavity, the capsule endoscope 10 can be introduced into the digestive cavity by taking it. For the non-digestive cavity, the capsule endoscope 10 can be introduced into the non-digestive cavity through a minimally invasive opening prescribed by clinical surgery. Hereinafter, the capsule endoscope 10 will be described in detail, taking the gastric cavity as an example.

FIG. 2A is a schematic diagram showing a scene of the capsule endoscope 10 according to the example of this embodiment. This embodiment provides a capsule endoscope 10 that can be made into a capsule shape (see FIG. 2A ) so as to be easily introduced into a digestive cavity such as the gastric cavity. The gastric cavity can be inspected and/or treated through the imaging device of the capsule endoscope 10, and after the inspection and/or treatment is completed, the capsule endoscope 10 can be expelled from the body.

In appearance, the capsule endoscope 10 may include a capsule-shaped housing 100 (see FIG. 2A ). The housing 100 may include a cylindrical main housing 100a and two dome-shaped end housings (a first end housing 100b and a second end housing) respectively provided at both axial ends of the main housing 100a. body 100c) to form a receiving space for arranging devices. In some examples, the apexes of the two end housings may pass through the central axis of the main housing 100a. In addition, the openings at both axial ends of the main housing 100a may be sealed by the first end housing 100b and the second end housing 100c respectively, thereby maintaining the liquid-tight state of the accommodation space.

In some examples, the main housing 100a and the first end housing 100b or the second end housing 100c may be integrally formed. This can improve liquid tightness and simplify the assembly process. In addition, the first end housing 100b and/or the second end housing 100c may be a transparent housing, and may transmit light of a specified wavelength (eg, visible light). Additionally, the main housing 100a may be a generally opaque housing for reasons such as reducing stray light.

Those skilled in the art can understand that the main housing 100a, the first end housing 100b and the second end housing 100c in FIG. 2A are examples and are not limited thereto. The length, diameter, wall thickness of the main housing 100a, the arc radius, wall thickness and other absolute values of the first end housing 100b and the second end housing 100c and their relative values can be adjusted according to actual needs. This article does not list the various designs. As an example, the wall thickness of the first end housing 100b may be equal to the wall thickness of the second end housing 100c, and the wall thickness of the first end housing 100b may also be greater than that of the second end housing 100c. Wall thickness.

In some examples, the capsule endoscope 10 may include an image acquisition device 11 disposed within a receiving space (see Figure 2A). The image capturing device 11 may be arranged at one end of the transparent housing and the lens assembly of the image capturing device 11 may face the transparent housing. In this case, the image capturing device 11 can collect the light incident through the transparent housing, thereby performing image capturing.

In some examples, the optical axis of image capture device 11 may be parallel to the central axis of housing 100 . In some examples, the optical axis of image capture device 11 and the central axis of housing 100 may be collinear. Referring to FIG. 2A , AA′ shows the central axis of the housing 100 . The image acquisition device 11 may be arranged in the accommodation space in such a manner that the optical axis is parallel to AA′ (further, the optical axis may be collinear with AA′). . On the one hand, the orientation of the capsule endoscope 10 is consistent with the orientation of the image capture device 11 , so that the orientation of the image capture device 11 can be easily adjusted by adjusting the orientation of the capsule endoscope 10 . On the other hand, when the transparent area of the transparent housing is fully utilized, the viewing angle of the image capturing device 11 can be further reduced.

In some examples, the capsule endoscope 10 may further include a built-in magnet 12 disposed within the receiving space (see FIG. 2A ). In this case, by applying magnetic action to the built-in magnet 12 by the electromagnetic device 20 (described in detail later), the capsule endoscope 10 can be magnetically guided to adjust the position of the capsule endoscope 10 in the gastric cavity, For example, the capsule endoscope 10 is moved to an area of interest (eg, a lesion area) to collect images.

In some examples, built-in magnet 12 may be a permanent magnet. In addition, the built-in magnet 12 may be in a cylindrical shape, such as a cylindrical shape. In some examples, the built-in magnet 12 may be in the shape of a cylinder with an aspect ratio no greater than 1, that is, a disk shape. That is to say, the length of the cylindrical built-in magnet 12 may not be greater than the diameter of the built-in magnet 12 . In addition, in other examples, the built-in magnet 12 may also be in the shape of a hollow cylinder.

In some examples, the central axis of built-in magnet 12 may be collinear with the central axis of housing 100 . Referring to Figure 2A, the built-in magnets 12 may be arranged with the central axis along AA'. In this case, the central axis of the built-in magnet 12 is consistent with the central axis of the housing 100 and the optical axis of the image capturing device 11 is consistent with the central axis of the housing 100. The orientation of the image capturing device 11 can be adjusted by adjusting the posture of the built-in magnet 12. Make adjustments, such as adjusting the deflection angle of the built-in magnet.

In some examples, the capsule endoscope 10 may also include an induction coil 13 (see Figure 2A). The induction coil 13 can generate an induction signal based on a changing magnetic field, and the induction signal can be an electrical signal such as a current signal, a voltage signal, or the like. In this case, the electromagnetic device 20 applies a changing magnetic field to the induction coil 13 and obtains an induction signal generated by the induction coil 13 based on the changing magnetic field. Thus, the position information of the induction coil 13 can be obtained using electromagnetic characteristics ( Described in detail later). In various embodiments, the sensed signal may be a digital signal or an analog signal.

In various embodiments, induction coil 13 and built-in magnet 12 may remain relatively stationary. That is to say, the built-in magnet 12 does not apply a changing magnetic field to the induction coil 13 .

When magnetically positioning the capsule endoscope 10 , it may be affected by various environmental magnetic fields, such as the geomagnetic field. These environmental magnetic fields are usually substantially static magnetic fields. In this case, by using the induction coil 13 to sense the dynamic magnetic field and generate an induction signal, the influence of the environmental magnetic field on the magnetic positioning can be effectively reduced.

In some examples, the central axis of induction coil 13 may be parallel to the central axis of housing 100 . In some examples, the central axis of induction coil 13 may be collinear with the central axis of housing 100 . Referring to FIG. 2A , the induction coil 13 may be arranged in the accommodation space in such a manner that the central axis is parallel to AA′ (further, the induction coil 13 may be arranged in such a manner that the central axis is collinear with AA′). In this case, the orientation of the capsule endoscope 10 can be easily acquired by acquiring the axial direction of the induction coil 13 .

In various embodiments, the coil area of the induction coil 13 may be 20mm ² to 80mm ² , for example, 20mm ² , 25mm ² , 30mm 2 , 35mm ² , 40mm ² , 45mm ² , 50mm ² , 55mm ^{2 ,} 60mm ² , 65mm ² , 70mm ² , 75mm ² , or 80mm ² . Preferably, the coil area of the induction coil 13 may be 40 mm ² to 60 mm ² . In addition, the number of turns of the induction coil 13 may be 50 to 500, such as 50, 100, 150, 200, 250, 300, 350, 400, 450, or 500. Preferably, the number of turns of the induction coil 13 may be 100 to 300. The wire diameter of the induction coil 13 may be 0.03mm to 0.3mm, for example, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm or 0.3mm . Preferably, the wire diameter of the induction coil 13 may be 0.05-0.2 mm.

In some examples, the number of induction coils 13 may be one or more, such as 1, 2, 3 or more. In some examples, the axial directions of the multiple induction coils 13 may also be different. The central axis of a part of the plurality of induction coils 13 may be parallel to the central axis of the housing 100 (further, may be collinear), and the central axis of another part may intersect with the central axis of the housing 100 .

FIG. 2B is a schematic structural diagram showing the image acquisition device 12 and the induction coil 13 of the capsule endoscope 10 according to the example of this embodiment. In some examples, induction coil 13 may be wrapped around the lens assembly of image capture device 11 (see Figure 2B). In addition, in order to conveniently obtain the orientation of the lens assembly of the image acquisition device 11 , the central axis of the induction coil 13 and the optical axis of the lens assembly of the image acquisition device 11 may be parallel. Further, the central axis of the induction coil 13 and the optical axis of the lens assembly of the image acquisition device 11 may be collinear. When there are multiple induction coils 13 , the central axis of part of the induction coils 13 may be parallel to the optical axis of the lens assembly, and the central axis of another part of the induction coils 13 may intersect with the optical axis of the lens assembly at a preset angle.

In some examples, the capsule endoscope 10 may further include a PCB 14 disposed within the accommodation space (see FIG. 2A ). MEMS memory (not shown) may be printed on PCB 14 . The memory may store images collected by the image acquisition device 11 and/or induction signals generated by the induction coil 13 .

In some examples, capsule endoscope 10 may also include a magnetic sensor (not shown). The magnetic sensor of the capsule endoscope 10 can be a mems sensor and can be printed on the PCB 14 . The magnetic sensor of the capsule endoscope 10 can sense the magnetic field of the built-in magnet 12, the magnetic field of an external device, and/or the environmental magnetic field, etc. In addition, the output data of the magnetic sensor of the capsule endoscope 10 and the output data of the induction coil 13 may have the same time stamp. In this case, through the cooperative use of the magnetic sensor and the induction coil 13, the influence of the environmental magnetic field can be further reduced, thereby further improving the accuracy of magnetic positioning.

In addition, in some examples, the magnetic sensor of the capsule endoscope 10 can also be used to magnetically detect the magnetic control device 20 to obtain the relative position of the magnetic control device 20 and the capsule endoscope 10 . The magnetic control device 20 is equivalent to a magnetic dipole moment, and based on the electromagnetic principle, the relative position of the magnetic control device 20 and the capsule endoscope 10 can be obtained (refer to Formula II below). In some examples, the number of magnetic sensors of the capsule endoscope 10 may be multiple, and two of them may be respectively arranged at both axial ends of the capsule endoscope 10 .

In some examples, the capsule endoscope 10 may further include an inertial sensor (not shown). In various embodiments, the inertial sensor may measure the inertial signal of the capsule endoscope 10 . In addition, the inertial signal measured by the inertial sensor and the induction signal measured by the induction coil 13 may have matching time information. For example, the inertial signal may include the measurement time, and the induction signal may also include the measurement time. This facilitates the fusion of inertial signals and induction signals.

Inertial sensors may include three-axis accelerometers and three-axis gyroscopes. The three-axis accelerometer and three-axis gyroscope can be mems devices and can be printed on PCB14. In various embodiments, the orientation of the inertial sensor and the orientation of the induction coil 13 may be the same or orthogonal. As a result, the inertial signal and the induction signal can be easily fused. In various embodiments, the inertial sensor may be oriented the same as or orthogonal to the central axis of housing 100 . In various embodiments, the inertial signal may include acceleration information of the capsule endoscope 10 measured by an accelerometer, and angular velocity information of the capsule endoscope 10 measured by a gyroscope.

In various embodiments, the acceleration a, displacement p (hereinafter sometimes also referred to as position p or coordinate p), attitude q, etc. of the capsule endoscope 10 can be obtained by solving the inertial signal. For example, the velocity υ of the capsule endoscope 10 can be obtained by solving the acceleration a, the displacement p of the capsule endoscope 10 can be obtained by solving the speed υ, and the capsule endoscope 10 can be obtained by solving the angular velocity ω. The posture q of mirror 10. The posture q of the capsule endoscope 10 may include the pitch angle, roll angle, and yaw angle of the capsule endoscope 10 .

As mentioned above, the orientation of the inertial sensor can be the same as the orientation of the housing 100. In this case, the pitch angle, roll angle and yaw angle obtained by solving the angular velocity measured by the inertial sensor can be regarded as the capsule-type internal The pitch angle, roll angle and yaw angle of the sight glass 10.

In addition, as mentioned above, the orientation of the inertial sensor and the orientation of the induction coil 13 may be the same. In this case, the pitch angle, roll angle and yaw angle obtained by calculating the angular velocity measured by the inertial sensor can also be regarded as The pitch angle, roll angle and yaw angle of the induction coil 13. That is, the pitch angle, roll angle and yaw angle obtained by calculating the angular velocity measured by the inertial sensor can be regarded as the orientation of the induction coil 13 in the world coordinate system.

In various embodiments, attitude calculation of inertial navigation can be performed based on the angular velocity ω and acceleration a of the capsule endoscope 10 . Specifically, based on the differential equations of attitude q, velocity υ, and position p, their solutions are derived and converted into approximate forms in discrete time, so that navigation information can be solved under discrete time sampling. details as follows:

(1) The differential equation of attitude q is as follows,

(2) The differential equation of velocity υ is as follows, where R _wb is the rotation matrix corresponding to the quaternion q, and g is the gravity acceleration:

(3) On the basis of solving υ, the differential equation of displacement p can be further obtained, as shown below:

The general solution to the above differential equation is as follows:

Based on the rotation matrix, R _wb is solved as follows:

in,

φ=|φ'|, that is, φ is the amplitude of vector φ',

Based on quaternions, the solution of q _wb is as follows:

in,

The solution for velocity υ is as follows:

The solution for displacement p is as follows:

or

Through the above-mentioned inertial navigation solution, the displacement p and attitude q of the capsule endoscope 10 are obtained.

In addition, when using the measurement results of inertial sensors for state estimation, the traditional approach is to estimate the inertial sensor output at each moment and continuously adjust the estimate through repeated iterations. When the sampling rate of the inertial sensor is higher than that of the induction coil 13, multiple iterations are required before updating the state quantity, which may result in excessive calculation and low calculation efficiency. In order to improve calculation efficiency, the pre-integration calculation method can be used. The main method is to integrate the output of the inertial sensor in the time period from the i-th to the j-th time (including multiple output moments of the inertial sensor), and combine it with the inertial The output of the sensor at the i-th moment is used to obtain the values of attitude q, speed υ, and position p at the j-th moment. Specifically, the state quantity (attitude q, speed υ, position p) at the j-th moment is the sum of the state quantity at the i-th moment and the integral value in the [i, j] time period. In this case, by calculating the integral value in the [i, j] time period, no repeated iterations are performed in this time period, thereby improving the calculation efficiency.

The attitude and coordinates of the capsule endoscope 10 obtained based on the inertial signal of the inertial sensor usually have intrinsic properties, that is, they are independent of the environment. The above attitude q and displacement p can be used to reflect the motion state of the capsule endoscope 10 . However, due to errors such as the inertial sensor itself (for example, the bias of the gyroscope and accelerometer, random walk and white noise, etc.), the attitude q and displacement p obtained based on the inertial signal of the inertial sensor may be less accurate. improve. In this case, by fusing the attitude q and displacement p obtained based on the inertial signal of the inertial sensor with the induction signal measured by the induction coil 13, the accuracy of the attitude and coordinates of the capsule endoscope 10 can be effectively improved.

Those skilled in the art can understand that the posture and coordinates of the capsule endoscope 10 obtained based on the induction signal of the induction coil 13 and the posture and coordinates of the capsule endoscope 10 obtained based on the inertial signal of the inertial sensor. There is a correlation between them, all in order to obtain the motion state of the capsule endoscope 10 . Based on this, the solution of the induction signal is optimized by fusing the inertial signal, or the induction signal is fused to optimize the solution of the inertial signal. As a result, the accuracy of calculating the inertial signal and/or the sensing signal can be effectively improved, thereby improving the accuracy of positioning the capsule endoscope 10 .

In some examples, using an error state Kalman filter algorithm (ESKF) and fusing sensing signals, the motion state obtained based on the inertial signal can be optimized, so that the motion state and/or coordinates of the capsule endoscope 10 can be optimized. optimization. In other examples, using the error state Kalman filter algorithm (ESKF) and fusing the inertial signal, the coordinates obtained based on the sensing signal can be optimized, so that the motion state and/or coordinates of the capsule endoscope 10 can be optimized. optimization.

In some examples, the calculation of measurements based on the magnetic sensor of the capsule endoscope 10 can also be optimized using an error state Kalman filter algorithm (ESKF) and fusing the inertial signals. Alternatively, the error state Kalman filter algorithm (ESKF) is used and the measurement value of the magnetic sensor of the capsule endoscope 10 is fused to optimize the solution of the inertial signal.

Specifically, the working principle of the Kalman filter algorithm ( _KF ) is as follows.

u _k-1 is the control variable at time k-1, which is a known quantity. Noise will be generated during the state transition process, which is described by Q. Calculate the covariance P of this step. According to the measurement result H of the induction coil and the corresponding measurement error R, x _k can be updated. The update process can be described by the Kalman gain K. After getting K, use what we got in the previous step

and observed

By performing a weighted average according to K, the optimal estimator can be obtained

details as follows:

The Kalman filter time update algorithm is as follows:

The Kalman filter state update algorithm is as follows:

ESKF (Error State Kalman Filter Algorithm) is a derivative of KF (Kalman Filter Algorithm), which changes the estimator into the error error plus the true value truth. The true value truth refers to the target (in this implementation, the target is The attitude q, speed υ and displacement p of the capsule endoscope 10), and the error error refers to the output error of the inertial sensor (random walk of the accelerometer and gyroscope, bias error of the gyroscope, etc.) and includes the inertial sensor Error target state error. By expressing the target pose as a form including errors, the covariance matrix P can be determined more accurately, and the Kalman gain K can be accurately calculated.

By replacing H in the above formula with the expression of the induced voltage E (described later) and updating the status, a more accurate position and attitude can be obtained. One induction coil 13 corresponds to an observation value, and an array composed of multiple induction coils corresponds to the observation value vector H.

In some examples, the central axis of the capsule endoscope 10 , the optical axis of the image acquisition module 11 , the magnetic axis of the built-in magnet 12 , and the central axis of the induction coil 13 may be collinear, and the orientation of the inertial sensor may be along the capsule. The central axis of the endoscope 10.

In some examples, the capsule endoscope 10 may further include a wireless transceiver module 15 disposed in the accommodation space (see FIG. 2A ). The wireless transceiver module 15 can transmit the images collected by the image acquisition device 11 , the induction signals generated by the induction coil 13 , etc. to the outside. Thereby, the image acquired by the image acquisition device 11, the induction signal generated by the induction coil 13, etc. can be easily transmitted to the outside. In addition, in order to facilitate real-time viewing of images collected by the image collection device 11 or real-time acquisition of the position of the capsule endoscope 10, etc., the wireless transceiver module 15 can communicate with the outside in real time.

In some examples, the capsule endoscope 10 may further include a power supply 16 disposed in the accommodation space (see FIG. 2A ). The power supply 16 can provide power for the image acquisition device 11, PCB 14, wireless transceiver module 15, etc. However, the examples of this embodiment are not limited to this. In other examples, for the purpose of miniaturizing the capsule endoscope 10 , the power supply 16 can also be arranged outside the capsule endoscope 10 , and through a wireless The method provides electric energy to the PCB 14, wireless transceiver module 15 and other devices placed in the accommodation space.

Those skilled in the art can understand that the arrangement positions of each device in the accommodation space in FIG. 2A are examples and are not limited thereto. For example, the positions of built-in magnet 12 and power source 16 in Figure 2A can be interchanged. In FIG. 2A , as an optional embodiment, the wireless transceiver module 15 may be arranged at one end of the accommodation space close to the second end housing 100c. In other embodiments, the wireless transceiver module 15 may also be arranged in the middle of the accommodation space.

As mentioned above, when using the capsule endoscope 10 to collect images in the gastric cavity, in order to collect images of the region of interest, it is usually necessary to use external equipment to guide the capsule endoscope 10 so that the capsule endoscope 10 can The endoscope 10 is moved to the site of interest and the lens assembly of the capsule endoscope 10 is directed toward the site of interest. To this end, this embodiment also provides an electromagnetic device 20 capable of exerting a magnetic effect on the capsule endoscope 10 for magnetic guidance of the capsule endoscope 10 .

FIG. 3A is a schematic diagram showing the electromagnetic device 20 according to the example of this embodiment. The electromagnetic device 20 of this embodiment may include an operating magnet 21 (see FIG. 3A). The operating magnet 21 can exert a magnetic effect on the built-in magnet 12 of the capsule endoscope 10 to magnetically guide the capsule endoscope 10, so that the capsule endoscope 10 is displaced.

In some examples, operating magnet 21 may include permanent magnet 211 (see Figure 3A). The permanent magnet 211 may be cylindrical, spherical, etc. Additionally, the magnetic axis of the permanent magnet 211 may be collinear with the central axis.

For the purpose of conveniently adjusting the magnetic field intensity applied by the permanent magnet 211 to the capsule endoscope 10 or guiding the capsule endoscope 10 to move in the vertical direction, the permanent magnet 211 may move along the vertical direction, for example , by reducing the height of the permanent magnet 211, the intensity of the magnetic field applied by the permanent magnet 211 to the capsule endoscope 10 can be increased.

For the purpose of guiding the capsule endoscope 10 to move in the horizontal direction, the permanent magnet 211 may move in the horizontal direction. For purposes such as adjusting the posture of the capsule endoscope 10, the permanent magnet 211 can also rotate, for example, around an axis along the horizontal direction.

It should be noted that, for convenience of description, FIG. 3A omits mechanisms such as support frames, robotic arms, and motors. Those skilled in the art can understand that the electromagnetic device 20 of this embodiment may also include a mechanical arm (not shown). The mechanical arm can drive the operating magnet 21 to move in the horizontal and vertical directions. The mechanical arm can also drive the permanent magnet 211 Turn.

In some examples, operating magnet 21 may also include a varying current-based electromagnet 212 (see Figure 3A). Electromagnet 212 may be a coil. By adjusting the current flowing into the electromagnet 212, the intensity of the magnetic field received by the capsule endoscope 10 can also be adjusted. In some examples, the magnetic field generated by electromagnet 212 is adjusted by adjusting the magnitude and/or direction of the current flowing in electromagnet 212 . In some examples, electromagnet 212 may be cylindrical. Additionally, the axis of electromagnet 212 may be along a vertical direction.

When guiding the capsule endoscope 10 , for purposes such as precise guidance, for example, to more accurately guide the capsule endoscope 10 to a site of interest, it is necessary to know the position of the capsule endoscope 10 during the guidance process. .

To this end, the electromagnetic device 20 may also include an electromagnetic coil 22 (see FIG. 3A), through which a changing magnetic field is applied to the induction coil 13 of the capsule endoscope 10, so that the induction coil 13 generates an induction signal. Further, The position information of the capsule endoscope 10 is obtained based on the induction signal generated by the induction coil 13 , for example, the relative coordinates of the capsule endoscope 10 and the electromagnetic device 20 are obtained.

In various embodiments, the electromagnetic coil 22 may be a wire-wound electromagnetic device. Passing current through the electromagnetic coil 22 generates a magnetic field. In addition, if the amplitude, direction, frequency, etc. of the current flowing through the electromagnetic coil 22 change, the magnetic field generated by the electromagnetic coil 22 may also change accordingly. For example, when the current amplitude increases, the intensity of the magnetic field generated by the electromagnetic coil 22 will increase, and when the direction of the current changes, the direction of the magnetic field generated by the electromagnetic coil 22 will change. In addition, the frequency of changes in the direction of the magnetic field generated by the electromagnetic coil 22 and the frequency of changes in the direction of the current may be the same.

In various embodiments, the current passed through the electromagnetic coil 13 may be a current that changes with a predetermined rule. As a result, the electromagnetic coil 13 can generate a changing magnetic field. In some embodiments, the current flowing through the electromagnetic coil 13 may be a direct current with varying amplitude. For example, the amplitude may gradually increase, gradually decrease, or increase-decrease-increase-decrease. The way changes. In other embodiments, the current flowing through the electromagnetic coil 13 may also be an alternating current whose direction changes at a predetermined frequency. For example, the predetermined frequency may be 500 Hz to 50 KHz.

As described above, the electromagnetic coil 22 of the electromagnetic device 20 can generate a magnetic field based on a current and can generate a changing magnetic field based on a changing current, and the induction coil 13 of the capsule endoscope 10 can generate a current based on the changing magnetic field. In this case, by passing a current that changes with a predetermined law into the electromagnetic coil 22, the electromagnetic coil 22 can generate a dynamic magnetic field with a known changing law, and the induction coil 13 can generate an induction signal based on the dynamic magnetic field (for example, induced current or induced voltage). Based on the basic parameters of the induction coil 13 and the electromagnetic coil 22 and the electromagnetic principles, the relative position between the induction coil 13 and the electromagnetic coil 22 can be obtained through calculation, specifically:

In formula I, μ ₀ represents vacuum permeability (permeability); N ₁ represents the number of turns of the electromagnetic coil 22, and S ₁ represents the coil area of the electromagnetic coil 22.

represents the orientation of the electromagnetic coil 22, I represents the amplitude of the current of the electromagnetic coil 22, f represents the alternating frequency of the current of the electromagnetic coil 22; E represents the induced voltage generated by the induction coil 13, and N ₂ represents the number of turns of the induction coil 13 , S ₂ represents the coil area of the induction coil 13,

Indicates the orientation of the induction coil 13,

Indicates the position vector of the induction coil 13 compared to the electromagnetic coil 22 (the relative coordinates of the induction coil 13 and the electromagnetic coil 22).

In addition, in Formula I, the number of turns N ₁ of the electromagnetic coil 22, the coil area S ₁ , and the direction

The amplitude I of the current, the alternating frequency f of the current, the number of turns N ₂ of the induction coil 13 and the coil area S ₂ are known quantities; the induced voltage E generated by the induction coil 13 can be obtained through observation. By calculating the orientation of the induction coil 13

and position vector

To obtain the relative position of the induction coil 13 and the electromagnetic coil 22 . Based on various known quantities and the observed quantity E, the orientation of the induction coil 13 can be determined.

and position vector

Estimation is performed to obtain the relative positions of the induction coil 13 and the electromagnetic coil 22 .

In some embodiments, the orientation of

and position vector

The unscented Kalman filter algorithm (UKF) can be used for estimation. Specifically, the unscented Kalman filter algorithm is a method that uses linear or nonlinear system state equations (see Formula I) to input observation data (for example, E in Formula I) to the system state (for example, orientation

and position vector

) estimation algorithm. In this algorithm, the observation quantity E is assumed to be Gaussian distributed, and based on Bayes' theorem, the direction is calculated

and position vector

In the posterior case (that is, after the observation E and its position in the Gaussian distribution are known), the conditional probability of the orientation

and position vector

Make an estimate.

In the above embodiment using the unscented Kalman filter algorithm (UKF), the Gaussian distribution of the observation quantity E can be based on the number of turns N ₁ of the electromagnetic coil, the coil area S ₁ , the orientation

It is established based on various parameters such as the amplitude I of the current, the alternating frequency f of the current, and the vertical and horizontal distances between the capsule endoscope 10 and the electromagnetic coil 22 .

In other embodiments, the orientation

and position vector

The LM nonlinear optimization algorithm (Levenberg-Marquardt algorithm) can also be used for estimation. The LM nonlinear optimization algorithm is a nonlinear least squares algorithm that uses gradients to find the maximum or minimum value. Specifically, when the observation quantity of E is known, the orientation

and position vector

Make a linear approximation within its domain and ignore derivative terms above the second order, thus transforming it into a linear least squares problem.

For example, when the observation quantity of E is known, perform the following steps: 1) Be the position vector

Set an initial value and an initial change range (usually can be set to the theoretical maximum range); 2) Center the initial value and find the first optimal value within the initial change range; 3) Based on the first Prefer the value to obtain the first calculated value of E; 4) Compare the first calculated value of E with the observed value of E. If the decrease in the calculated value of E compared to the observed value of E is within the predetermined threshold, then set the first change range, and execute the rules from steps 2) to 4) above, that is, center on the first preferred value. Find the second preferred value within the first variation range, obtain the second calculated value of E based on the second preferred value, and compare the second calculated value of E with the observed value of E. If the decrease in the calculated value of E compared to the observed value of E is outside the predetermined threshold, the change range is reset and the rules from steps 2) to 4) above are executed. From this, the orientation

and position vector

Make an estimate.

FIG. 4 is a schematic diagram showing coordinate system conversion according to the example of this embodiment. In the embodiment shown in Figure 4, (W) represents the world coordinate system, where _xw , _yw and _zw are the three coordinate axes of the world coordinate system respectively. (D) represents the coordinate system of the operating magnet 21, where x _d , y _d and z _d are respectively the three coordinate axes of the coordinate system of the operating magnet 21 . (C) represents the coordinate system of the electromagnetic coil 22, where x _c , y _c and z _c are respectively the three coordinate axes of the coordinate system of the electromagnetic coil 22 . (E) represents the coordinate system of the capsule endoscope 10 , where x _e , y _e , and _ze are respectively the three coordinate axes of the coordinate system of the capsule endoscope 10 .

In the embodiment shown in FIG. 4 , after the above calculation, the coordinates of the induction coil 13 in the coordinate system of the electromagnetic coil 22 (that is, the relative position of the induction coil 13 and the electromagnetic coil 22 ) and the world coordinate of the induction coil 13 are obtained. The coordinates of the induction coil 13 in the world coordinate system can be obtained by fusing the coordinates of the electromagnetic coil 22 in the world coordinate system with the orientation in the world coordinate system. Furthermore, by fusing the coordinates of the operating magnet 21 in the world coordinate system, the coordinates of the induction coil 13 in the coordinates of the operating magnet 21 (ie, the relative position of the induction coil 13 and the operating magnet 21) can be obtained. Thereby, the relative coordinates of the capsule endoscope 10 and the electromagnetic device 20 are obtained.

In various embodiments, the coil area of the electromagnetic coil 13 may be 50mm ² to 300mm ² , for example, 50mm ² , 60mm ² , 70mm ² , 80mm ² , 90mm ² , 100mm ² , 110mm ² , 120mm ² , 130mm ² , 113mm ² , 140mm ² , 150mm ² , 200mm ² , 250mm ² , or 300mm ² . Preferably, the coil area of the electromagnetic coil 13 may be 80 to 200 mm ² . In addition, the number of turns of the electromagnetic coil 13 may be 50 to 500, 50, 100, 150, 200, 250, 300, 350, 400, 450, or 500. Preferably, the number of turns of the electromagnetic coil 13 may be 100 to 300. The wire diameter of the electromagnetic coil 13 may be 0.3mm to 0.8mm, for example, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, or 0.8mm. Preferably, the wire diameter of the electromagnetic coil 13 may be 0.4mm to 0.7mm.

In some examples, electromagnetic coil 13 may be cylindrical. Additionally, in some examples, the ratio of the length to the diameter of the electromagnetic coil 13 may be 0.5 to 1.5, such as 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, or 1.5.

FIG. 3B shows an arrangement example of the electromagnetic coil 22 involved in this embodiment example. In various embodiments, the number of electromagnetic coils 22 may be one or more (see Figures 3A and 3B). In this case, multiple induction signals are generated by multiple electromagnetic coils 22 and the relative positions of the capsule endoscope 10 and the electromagnetic device 20 are obtained based on the multiple induction signals, which can help to further improve magnetic positioning. Accuracy.

It should be noted that, for the sake of simplicity of description, a reference number is given to one of the plurality of electromagnetic coils 22 in FIGS. 3A and 3B .

In various embodiments, the number of the plurality of electromagnetic coils 22 may be 6 to 36, optionally 6, 8, 9, 12, 15, 16, 25, 36. The plurality of electromagnetic coils 22 may be arranged in an array. In some examples, the array formed by the arrangement of the plurality of electromagnetic coils 22 may be an equally spaced array. In other examples, the row spacing and/or column spacing of the array formed by the arrangement of the plurality of electromagnetic coils 22 may gradually decrease from the center to the periphery (see FIG. 3B ). In the embodiment shown in FIG. 3B , the distance between row R0 and row R1 may be greater than the distance between row R1 and row R2, and the distance between column C0 and column C1 may be greater than the distance between column C1 and column C2.

In some examples, multiple electromagnetic coils 22 may be arranged along a horizontal plane. In this case, the vertical coordinates of each electromagnetic coil 22 are the same, which can help simplify calculations. In addition, the electromagnetic device 20 may also include a platform 23 located below the capsule endoscope 10 (see FIG. 3A ). A plurality of electromagnetic coils 22 may be arranged on the platform 23 . In some examples, the platform 23 may be an examination bed, and the subject may lie flat on the examination bed to receive the examination.

In some examples, the planar size of the array formed by the arrangement of the plurality of electromagnetic coils 22 can be from 200mm*200mm to 400mm*400mm, for example, 200mm*200mm, 200mm*300mm, 200mm*400mm, 300mm*300mm, 300mm*400mm , or 400mm*400mm, etc.

In some examples, the plurality of electromagnetic coils 22 may be arranged so that each electromagnetic coil 22 is oriented in the same direction, for example, the orientation of each electromagnetic coil 22 may be along a vertical direction. In other examples, the plurality of electromagnetic coils 22 may be arranged such that at least two electromagnetic coils 22 have different orientations, for example, the orientation of one or a part of the electromagnetic coils 2 may be orthogonal to the orientation of another or another part of the electromagnetic coils 2 . In addition, the plurality of electromagnetic coils 22 may also be arranged so that the directions of the respective electromagnetic coils 22 are different. In this case, diversified magnetic fields are generated toward different electromagnetic coils 22 to obtain diversified induction signals, which can help further improve the magnetic positioning accuracy.

In some examples, current (eg, alternating current) may be applied to each electromagnetic coil 22 in a time-divided manner, for example, current may be applied to each electromagnetic coil 22 in sequence. Additionally, the magnitude and/or frequency of the current applied to each solenoid coil 22 may be the same. In this case, by matching the time stamps of current applied to each electromagnetic coil 22, the electromagnetic coil 22 corresponding to each induction signal can be determined simply. Specifically, the electromagnetic coil 22 is marked with a time stamp when a current is applied, and each induction signal is also stamped with a time stamp. By matching the two timestamps, the electromagnetic coil 22 corresponding to each induction signal can be determined. .

In other examples, current (eg, alternating current) may also be applied to each electromagnetic coil 22 at the same time. In addition, the amplitude of the current applied to each electromagnetic coil 22 may be the same and the frequency may be different. In this case, by matching the frequency of the current applied to each electromagnetic coil 22, the electromagnetic coil 22 corresponding to each induction signal can be easily determined.

In addition, the electromagnetic device 20 may also include a magnetic sensor array (not shown). The magnetic sensor array of the electromagnetic device 20 can sense the built-in magnet 12 of the capsule endoscope 10 to obtain the relative coordinates of the electromagnetic device 20 and the capsule endoscope 10 . In some examples, the magnetic sensor array of electromagnetic device 20 may be disposed on examination table 23 . In some examples, the magnetic sensor arrays and electromagnetic coils 22 of electromagnetic device 20 may be arranged in a staggered manner. In addition, those skilled in the art can understand that the postures, coordinates, etc. of each component of the electromagnetic device 20 in the world coordinate system can be preset as known quantities, and the relative positions between the components of the capsule endoscope 10 It can also be preset as a known quantity to obtain the relative coordinates of the built-in magnet 12 compared to the magnetic sensor of the electromagnetic device, or the relative coordinates of the induction coil 13 compared to the electromagnetic coil 22, and then other coordinates can be obtained through coordinate conversion. The relative coordinates between parts.

Specifically, the built-in magnet 12 is equivalent to a magnetic dipole moment. Based on Formula II and various known quantities, the relative coordinates of the capsule endoscope 10 and the electromagnetic device 20 can be obtained:

Wherein, _μ0 is the vacuum magnetic permeability (permeability), M is the module of the equivalent magnetic moment of the built-in magnet 12, r is the distance between the capsule endoscope 10 and the magnetic sensor array of the electromagnetic device 20,

is the unit vector of the magnetic moment direction of the built-in magnet 12, indicating the posture orientation of the built-in magnet 12 (that is, the posture orientation of the capsule endoscope 10),

is the position vector of the built-in magnet 12 in the coordinate system of the magnetic sensor array of the electromagnetic device 20 . In the above formula II, r,

is an unknown quantity, M is a known quantity, and B can be known through measurement. Through the unscented Kalman filter algorithm, the above r,

That is, the relative coordinates of the capsule endoscope 10 and the magnetic sensor array of the electromagnetic device 20, and the posture of the capsule endoscope 10.

As described above, the posture and/or coordinates of the capsule endoscope 10 are obtained based on the calculation of the measurement value of the magnetic sensor array of the electromagnetic device 20, and the capsule endoscope is obtained based on the inertial signal of the inertial sensor. 10's posture and/or coordinates, and there is a correlation between the two. If the measurement error and solution deviation are small enough, they can be considered equivalent. Based on this, by fusing inertial signals to optimize the calculation of the measurement values of the magnetic sensor array of the electromagnetic device 20 , or fusing the measurement values of the magnetic sensor array of the electromagnetic device 20 to optimize the calculation of the inertial signals, it is possible to effectively improve The accuracy of positioning the capsule endoscope 10 can be improved by calculating the accuracy of the inertial signal and/or the measurement value of the magnetic sensor array of the electromagnetic device 20 .

In addition, in some examples, the solution of the measured values of the magnetic sensor array based on the electromagnetic device 20 can also be optimized by using the error state Kalman filter algorithm (ESKF) and fusing the inertial signals. Alternatively, the solution of the inertial signal can be optimized by using the error state Kalman filter algorithm (ESKF) and fusing the measurement values of the magnetic sensor array of the electromagnetic device 20 . As a result, the accuracy of solving the inertial signal and/or the measurement value of the magnetic sensor array of the electromagnetic device 20 can be improved.

FIG. 5 shows the magnetic positioning method according to this embodiment. Hereinafter, the positioning method for positioning the capsule endoscope 10 according to this embodiment will be described in detail with reference to FIG. 5 .

Referring to Figure 5, the method for positioning the capsule endoscope 10 may include the following steps: applying a dynamic magnetic field to the capsule endoscope 10 (step S110); collecting the induction signal generated by the induction coil 13 (step S120); calculating the induction Relative coordinates of coil 13 (step S130).

In various embodiments, in step S110, the dynamic magnetic field may include a plurality of changing magnetic fields generated sequentially in time sequence. In some examples, the changing frequencies and central field strengths of the plurality of changing magnetic fields may be the same. In some examples, the coordinates of the plurality of changing magnetic fields along the vertical direction may be the same. In some examples, the above-mentioned multiple changing magnetic fields are marked with timestamps to record various time information such as generation time and duration. In addition, the magnetic axes of at least two magnetic fields among the plurality of changing magnetic fields may be different. In various embodiments, the dynamic magnetic field described above may be generated by the electromagnetic coil 22 referred to herein.

In addition, in various embodiments, before performing step S110, it can also be sensed whether there is a changing magnetic field in the surrounding environment of the capsule endoscope 10. If there is, it is necessary to measure the changing law of the magnetic field to perform subsequent operations. The influence of this magnetic field is subtracted during processing.

In various embodiments, in step S120 , the induction signal may be a voltage signal generated by the induction coil 13 . In various embodiments, the voltage signal generated by induction coil 13 may be a digital signal. In various embodiments, the induction signal generated by the induction coil 13 may be transmitted to the outside via the wireless transceiver module 15 . In various embodiments, the sensing signal may be collected in real time.

In various embodiments, in step S120, the induction signal generated by the induction coil 13 may be time-stamped to record the generation time and duration of the induction signal. In addition, the time stamp of the induction signal has a matching relationship with the time stamp of the dynamic magnetic field, so that the induction signal corresponding to each changing magnetic field is determined through the time stamp.

In various embodiments, in step S130, based on the voltage signal generated by the induction coil 13, various parameters of the induction coil 13, and the physical characteristics of the dynamic magnetic field in step S110, combined with the electromagnetic principle, it can be solved The relative coordinates between the induction coil 13 and the source of the dynamic magnetic field. In various embodiments, the relative coordinates between the induction coil 13 and the source of the dynamic magnetic field can be solved through the unscented Kalman filter algorithm or the Levenberg-Marquardt algorithm. Then, the relative coordinates between the capsule endoscope 10 and the source of the dynamic magnetic field are obtained.

FIG. 6 illustrates a method for optimizing positioning results by combining inertial sensors according to this embodiment. Below, the positioning optimization method will be described in detail with reference to Figure 6.

Referring to FIG. 6 , the optimization method for positioning the capsule endoscope 10 may include the following steps: obtaining an estimate of the attitude and/or coordinates of the capsule endoscope 10 (step S210 ); Observed values of attitude and/or coordinates (step S220); optimize the estimated value based on the observed values (step S230).

In various embodiments, in step S210, based on the induction signal measured by the induction coil 13 described herein, the inertial signal measured by the inertial sensor, the measurement value of the magnetic sensor of the capsule endoscope 10, and/or The measured value of the magnetic sensor of the electromagnetic device 20 can be used to obtain an estimated value of the coordinates and attitude of the capsule endoscope 10 using, for example, an unscented Kalman filter algorithm, a LM optimization algorithm, etc.

In various embodiments, in step S220, the observation object may be the induction signal measured by the induction coil 13 described herein, the inertial signal measured by the inertial sensor, the measured value of the magnetic sensor of the capsule endoscope 10, and/or measurements from the magnetic sensors of the electromagnetic device 20 . Those skilled in the art can understand that the solution object in step S210 and the observation object in step S220 may be different.

In various embodiments, in step S230, the estimated value obtained in step S210 can be optimized by fusing the observation values obtained in step S220 and using, for example, an error state Kalman filter algorithm (ESKF), so as to The coordinates and attitude of the capsule endoscope 10 are obtained more accurately. For example, estimates can be optimized using a Kalman gain as a weighted average of estimates and results based on observations.

In the magnetic control system 1 of the present disclosure, the inertial signal of the instrument 10 is measured by the inertial sensor, and the magnetic field generated by the electromagnetic coil 22 is measured by the induction coil 13, and the inertial signal and the induction signal are fused, thereby improving the resolution of the inertial signal. and/or the accuracy of the sensing signal, thereby improving the positioning accuracy of the instrument 10 .

In some embodiments, the capsule endoscope system 1 may further include a processing device 30 (see Figure 1). The processing device 30 can perform the calculation of the above formula I to obtain the position of the capsule endoscope 10, image processing, and the like. In addition, the processing device 30 may perform the above positioning method. In addition, the processing device 30 can also perform the above optimization method.

In addition, the capsule endoscope system 1 may further include a communication device 40 (see FIG. 1 ). The communication device 40 can communicate with the wireless transceiver module 15 to receive, for example, images collected by the image acquisition device 11 , induction signals generated by the induction coil 13 , and the like.

In addition, the capsule endoscope system 1 may further include a display device 50 (see FIG. 1 ). The display device 50 may be used to display images captured by the image capture device 11 . In addition, the capsule endoscope system 1 may also include a storage unit 60 (see FIG. 1 ). The storage unit 60 may store images collected by the image acquisition device 11 , induction signals generated by the induction coil 13 , and the like.

Although the present disclosure has been specifically described above in conjunction with the accompanying drawings and examples, it should be understood that the above description does not limit the present disclosure in any form. Those skilled in the art can make modifications and changes to the disclosure as necessary without departing from the essential spirit and scope of the disclosure, and these modifications and changes all fall within the scope of the disclosure.

Claims (10)

1. A magnetic control system that integrates inertial measurement, characterized by including instruments, electromagnetic equipment and processing devices. The instruments include inertial sensors and induction coils that generate induction signals based on changing magnetic fields. The electromagnetic equipment includes based on changing magnetic fields. An electromagnetic coil generates a changing magnetic field through electric current. The induction coil receives the changing magnetic field generated by the electromagnetic coil and generates an induction signal. The processing device fuses the inertial signal measured by the inertial sensor and the inertial signal generated by the induction coil. The induction signal is used to obtain the motion state of the instrument and the relative coordinates of the instrument and the electromagnetic device.
2. The magnetic control system according to claim 1, wherein the motion state includes the acceleration of the instrument and the attitude angle of the instrument, and the induction signal is a voltage signal or a current signal.
3. The magnetic control system according to claim 1, wherein the processing device optimizes the motion state based on the induction signal and an error state Kalman filter algorithm; or, the processing device optimizes the motion state based on the inertial signal. and error state Kalman filter algorithm to optimize the relative coordinates.
4. The magnetic control system according to claim 1, characterized in that the orientation of the inertial sensor is the same as or orthogonal to the orientation of the induction coil.
5. The magnetic control system according to claim 1, wherein the inertial signal and the induction signal have matching time information.
6. The magnetic control system according to claim 1, wherein the inertial sensor includes an accelerometer and a gyroscope.
7. The magnetic control system according to claim 5, characterized in that the positional relationship between the induction coil and the electromagnetic coil satisfies:

   

   Among them, μ ₀ represents the vacuum magnetic permeability, N ₁ represents the number of turns of the electromagnetic coil, S ₁ represents the coil area of the electromagnetic coil,

   

   represents the orientation of the electromagnetic coil, I represents the amplitude of the current of the electromagnetic coil, f represents the alternating frequency of the current of the electromagnetic coil, E represents the induction signal generated by the induction coil, and N ₂ represents the The number of turns of the induction coil, S ₂ represents the coil area of the induction coil,

   

   Indicates the orientation of the induction coil,

   

   Indicates the relative coordinates of the induction coil compared to the electromagnetic coil.
8. The magnetic control system according to claim 5, characterized in that the number of the electromagnetic coils is multiple.
9. The magnetic control system according to claim 1, characterized in that the instrument further includes a built-in magnet arranged in the accommodation space, the electromagnetic device further includes an operating magnet, the operating magnet exerts a force on the built-in magnet. Magnetism acts to cause displacement of the instrument.
10. The magnetic control system according to claim 9, wherein the operating magnet includes a permanent magnet and an electromagnet based on changing current.

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