CN109620104B - Capsule endoscope and positioning method and system thereof - Google Patents
Capsule endoscope and positioning method and system thereof Download PDFInfo
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- CN109620104B CN109620104B CN201910021483.6A CN201910021483A CN109620104B CN 109620104 B CN109620104 B CN 109620104B CN 201910021483 A CN201910021483 A CN 201910021483A CN 109620104 B CN109620104 B CN 109620104B
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B1/00—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor
- A61B1/00147—Holding or positioning arrangements
- A61B1/00158—Holding or positioning arrangements using magnetic field
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B1/00—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor
- A61B1/04—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor combined with photographic or television appliances
- A61B1/041—Capsule endoscopes for imaging
Abstract
The invention is suitable for the technical field of three-dimensional positioning, and provides a capsule endoscope and a positioning method and a system thereof, wherein a magnetic sensor and a magnet inside the capsule endoscope are arranged inside the capsule endoscope, the magnetic sensor is used for measuring the magnetic field of a driving magnet for driving the capsule endoscope to move, so as to obtain the magnetic field measurement value of the driving magnet, measure the spin angle of the capsule endoscope, obtain the spin angle measurement value of the capsule endoscope, calculate the pose information of the capsule endoscope relative to the driving magnet according to the magnetic field measurement value, the angle measurement value, a preset driving magnetic field model and a preset optimization algorithm of the driving magnet, and determine the pose information of the capsule endoscope in a world coordinate system according to the pose information of the driving magnet in the world coordinate system and the pose information of the capsule endoscope relative to the driving magnet, thereby avoiding the positioning process of the capsule endoscope from being influenced by, effectively improves the positioning accuracy of the capsule endoscope.
Description
Technical Field
The invention belongs to the technical field of three-dimensional positioning, and particularly relates to a capsule endoscope and a positioning method and system thereof.
Background
A capsule endoscope, also called an intelligent capsule endoscope system, is a capsule-shaped endoscope. The capsule endoscope is internally provided with a camera shooting and signal transmission device, is orally taken by a detected person, moves in the alimentary canal and shoots images so as to obtain the images of the inner part of the alimentary canal of the detected person. Compared with the traditional endoscope, the capsule endoscope can not cause wound to the examinee, does not influence the movement of the examinee, and is very convenient. In order to control the capsule endoscope to detect the digestive tract system of the human body more accurately, the position of the capsule endoscope in the human body needs to be positioned in real time.
Disclosure of Invention
The embodiment of the invention provides a capsule endoscope and a positioning method and system thereof, aiming at improving the positioning accuracy of the capsule endoscope.
The embodiment of the invention provides a positioning method of a capsule endoscope, wherein a magnetic sensor and a magnet in the capsule endoscope are arranged inside the capsule endoscope, and the method comprises the following steps:
measuring the magnetic field of a driving magnet which drives the capsule endoscope to move through the magnetic sensor to obtain the magnetic field measured value of the driving magnet;
measuring the spin angle of the capsule endoscope to obtain a measurement value of the spin angle of the capsule endoscope;
calculating the pose information of the capsule endoscope relative to the driving magnet according to the magnetic field measurement value of the driving magnet, the spin angle measurement value, a preset driving magnetic field model and a preset optimization algorithm;
and determining the pose information of the capsule endoscope in the world coordinate system according to the pose information of the driving magnet in the world coordinate system and the pose information of the capsule endoscope relative to the driving magnet.
Further, the step of measuring a magnetic field of a driving magnet for driving the capsule endoscope to move by a magnetic sensor includes:
acquiring a first magnetic field value measured in advance, wherein the first magnetic field value is the total magnetic field value of the magnet inside the capsule endoscope, the geomagnetic field and the ambient magnetic field without being influenced by the driving magnet;
measuring by the magnetic sensor to obtain a second magnetic field value, wherein the second magnetic field value is the total magnetic field value of the driving magnet, the magnet inside the capsule endoscope, the geomagnetic field and the magnetic field of the surrounding environment;
and calculating the magnetic field measurement value of the driving magnet according to the first magnetic field value and the second magnetic field value.
Further, the step of calculating the pose information of the capsule endoscope with respect to the driving magnet includes:
calculating a magnetic field measurement error of the driving magnet according to the driving magnetic field model, the magnetic field measurement value of the driving magnet and the measurement value of the spin angle;
and minimizing the magnetic field measurement error of the driving magnet through the optimization algorithm to obtain the pose information of the capsule endoscope relative to the driving magnet.
Still further, before the step of performing magnetic field measurement by a magnetic sensor on a driving magnet that drives the capsule endoscope to move, the method further comprises:
acquiring the distance between the magnetic sensor and the center of the capsule endoscope and acquiring the relative magnetic permeability of the driving magnet;
and constructing the driving magnetic field model according to the magnetic dipole model, the distance between the magnetic sensor and the center of the capsule endoscope and the relative magnetic permeability of the driving magnet.
Furthermore, at least two magnetic sensors are arranged inside the capsule endoscope, and the magnetic sensors are three-axis magnetic sensors.
Furthermore, an inertial sensor is arranged inside the capsule endoscope and used for measuring the spin angle of the capsule endoscope.
An embodiment of the present invention further provides a capsule endoscope, including: a magnetic sensor disposed in the capsule endoscope, a magnet in the capsule endoscope, and a spin angle measurement sensor;
the magnetic sensor is used for measuring the magnetic field of a driving magnet which drives the capsule endoscope to move, and obtaining the magnetic field measurement value of the driving magnet;
the magnetic sensors comprise a first magnetic sensor and a second magnetic sensor, and the first magnetic sensor and the second magnetic sensor are arranged on a circuit board in the capsule endoscope in a scattered welding mode;
the spin angle measuring sensor is used for measuring the spin angle of the capsule endoscope, so that the positioning system calculates the pose information of the capsule endoscope relative to the driving magnet according to the measured value of the spin angle obtained from the magnetic sensor and by combining a preset driving magnetic field model and a preset optimization algorithm, and determines the pose information of the capsule endoscope in a world coordinate system according to the pose information of the driving magnet in the world coordinate system and the position information of the capsule endoscope relative to the driving magnet.
Still further, the first secondary sensor or the second magnetic sensor is a three-axis magnetic sensor.
Still further, the spin angle measurement sensor includes an inertial sensor.
Still further, the magnetic sensor includes two or more dispersed first sensors or second sensors.
The embodiment of the invention provides a positioning system, which is used for positioning pose information of a capsule endoscope in a world coordinate system, and the capsule endoscope comprises: a magnetic sensor disposed in the capsule endoscope, a magnet in the capsule endoscope, and a spin angle measurement sensor; the magnetic sensor is used for measuring the magnetic field of a driving magnet which drives the capsule endoscope to move, and obtaining the magnetic field measurement value of the driving magnet; the magnetic sensors comprise a first magnetic sensor and a second magnetic sensor, and the first magnetic sensor and the second magnetic sensor are arranged on a circuit board in the capsule endoscope in a scattered welding mode; the spin angle measuring sensor is used for measuring the spin angle of the capsule endoscope;
the positioning system includes: a receiver and a processing device;
the receiver for obtaining magnetic field measurements of the drive magnet from the magnetic sensor and measurements of the spin angle from the spin angle measurement sensor;
and the processing device is used for calculating the pose information of the capsule endoscope relative to the driving magnet according to the magnetic field measurement value of the driving magnet obtained by the magnetic sensor and the spin angle measurement value obtained by the spin angle measurement sensor by combining a preset driving magnetic field model and a preset optimization algorithm, and according to the pose information of the driving magnet in a world coordinate system.
Still further, the capsule endoscope comprises a radio frequency module, the first magnetic sensor, the second magnetic sensor and the spin angle measurement sensor are connected with the radio frequency module, the first magnetic sensor and the second magnetic sensor respectively send the magnetic field measurement value of the driving magnet to the receiver through the radio frequency module, and the spin angle measurement sensor sends the measurement value of the spin angle to the receiver through the radio frequency module.
Furthermore, the processing device is further configured to calculate a magnetic field measurement error of the driving magnet according to the driving magnetic field model, the magnetic field measurement value of the driving magnet, and the measurement value of the spin angle; and minimizing the magnetic field measurement error of the driving magnet through the optimization algorithm to obtain the pose information of the capsule endoscope relative to the driving magnet.
Still further, the processing device is further used for acquiring the distance between the magnetic sensor and the center of the capsule endoscope and acquiring the relative permeability of the driving magnet; and constructing the driving magnetic field model according to the magnetic dipole model, the distance between the magnetic sensor and the center of the capsule endoscope and the relative magnetic permeability of the driving magnet.
The embodiment of the invention also provides a positioning system for positioning a capsule endoscope, wherein a magnetic sensor and a magnet in the capsule endoscope are arranged in the capsule endoscope, and the positioning system comprises:
the magnetic field measuring unit is used for measuring the magnetic field of a driving magnet for driving the capsule endoscope to move through a magnetic sensor to obtain the magnetic field measured value of the driving magnet;
the spin measuring unit is used for measuring the spin angle of the capsule endoscope and obtaining the measured value of the spin angle of the capsule endoscope;
the relative pose calculation unit is used for calculating pose information of the capsule endoscope relative to the driving magnet according to the magnetic field measurement value of the driving magnet, the spin angle measurement value, a preset driving magnetic field model and a preset optimization algorithm; and
and the capsule pose determining unit is used for determining the pose information of the capsule endoscope in the world coordinate system according to the pose information of the driving magnet in the world coordinate system and the pose information of the capsule endoscope relative to the driving magnet.
Still further, the magnetic field measurement unit includes:
the first magnetic field value acquisition unit is used for acquiring a first magnetic field value measured in advance, wherein the first magnetic field value is the total magnetic field value of the magnet in the capsule endoscope, the geomagnetic field and the ambient magnetic field under the condition of not being influenced by the driving magnet;
the second magnetic field value measuring unit is used for measuring a second magnetic field value through the magnetic sensor, wherein the second magnetic field value is the total magnetic field value of the driving magnet, the magnet inside the capsule endoscope, the geomagnetic field and the ambient magnetic field; and
and the magnetic field value calculation unit is used for calculating the magnetic field measurement value of the driving magnet according to the first magnetic field value and the second magnetic field value.
Still further, the relative pose calculation unit includes:
an error calculation unit for calculating a magnetic field measurement error of the driving magnet based on the driving magnet model, the magnetic field measurement value of the driving magnet, and the spin angle measurement value; and
and the error minimization unit is used for minimizing the magnetic field measurement error of the driving magnet through the optimization algorithm to obtain the pose information of the capsule endoscope relative to the driving magnet.
Still further, the positioning system further comprises:
the parameter acquisition unit is used for acquiring the distance between the magnetic sensor and the center of the capsule endoscope and acquiring the relative magnetic permeability of the driving magnet; and
and the magnetic field model building unit is used for building the driving magnetic field model according to the magnetic dipole model, the distance between the magnetic sensor and the center of the capsule endoscope and the relative magnetic permeability of the driving magnet.
The invention measures the magnetic field of the driving magnet through the magnetic sensor to obtain the magnetic field measurement value of the driving magnet, measures the spin angle of the capsule endoscope at the same time to obtain the measurement value of the spin angle of the capsule endoscope, calculates the pose information of the capsule endoscope relative to the driving magnet according to the magnetic field measurement value, the measurement value of the spin angle, a preset driving magnetic field model and a preset optimization algorithm, and then obtains the pose information of the capsule endoscope in a world coordinate system according to the pose information of the driving magnet in the world coordinate system, thereby positioning the capsule endoscope according to the magnetic field measurement value of the driving magnet, the driving magnetic field model, the measurement value of the spin angle and the optimization algorithm, avoiding the positioning process of the capsule endoscope from being influenced by the magnetic field of the driving magnet, and improving the positioning accuracy of the capsule.
Drawings
FIG. 1 is a flowchart illustrating a method for positioning a capsule endoscope according to an embodiment of the present invention;
FIG. 2 is an exemplary diagram of three axial directions of an inertial sensor in a method for positioning a capsule endoscope according to an embodiment of the present invention;
FIG. 3 is a flowchart of a positioning method for a capsule endoscope according to a second embodiment of the present invention;
FIG. 4 is a schematic structural diagram of a capsule endoscope provided in the third embodiment of the present invention;
fig. 5 is a schematic structural diagram of a positioning system according to a fourth embodiment of the present invention;
fig. 6 is a schematic structural diagram of a positioning system according to a fourth embodiment of the present invention;
FIG. 7 is a schematic structural diagram of a positioning system for positioning a capsule endoscope according to a fifth embodiment of the present invention; and
fig. 8 is a schematic structural diagram of a preferred positioning system for positioning a capsule endoscope according to a fifth embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
At present, the positioning modes mainly comprise optical positioning, ultrasonic positioning, ray positioning and magnetic positioning, the optical positioning is not suitable for in-vivo positioning, the ultrasonic positioning precision is not high, and the ray positioning has radiativity. The capsule endoscope is internally provided with a small magnet, a magnetic control system outside a human body is provided with a large magnet, the large magnet and the small magnet are both permanent magnets, the large magnet is used as a driving magnet in the magnetic control system and is used for providing a driving magnetic field, and the capsule endoscope moves in a digestive system of the human body under the driving of the driving magnetic field. In the existing magnetic positioning technology, the position of the capsule endoscope is obtained by measuring the magnetic field change of the small magnet, however, the magnetic field intensity of the large magnet is large, and the measurement of the magnetic field intensity of the small magnet is influenced, so that the positioning accuracy of the capsule endoscope is not high. In the invention, the position and attitude information of the capsule endoscope is determined by measuring the magnetic field of the driving magnet and according to the driving magnetic field model, the spin angle of the capsule endoscope and the optimization algorithm, so that the influence of the driving magnetic field on the positioning accuracy is effectively avoided, and the positioning accuracy of the capsule endoscope is improved.
Example one
Fig. 1 shows a flow of implementing a positioning method for a capsule endoscope according to an embodiment of the present invention, and for convenience of description, only the parts related to the embodiment of the present invention are shown, which are detailed as follows:
in step S101, magnetic field measurement is performed by the magnetic sensor on the drive magnet that drives the capsule endoscope to move, and a magnetic field measurement value of the drive magnet is obtained.
In the embodiment of the invention, the capsule endoscope is internally provided with the magnetic sensor and the magnet in the capsule endoscope, and the driving magnet outside the capsule endoscope drives the capsule endoscope to move through interaction with the magnet in the capsule endoscope. In the process of driving the capsule endoscope to move, the capsule endoscope needs to be positioned in real time, and as the relative pose between the magnet in the capsule endoscope and the driving magnet is different when the pose of the capsule endoscope changes, the magnetic field at the position of the capsule endoscope also changes. Therefore, when the capsule endoscope is positioned, the magnetic field intensity of the driving magnet is measured by the magnetic sensor inside the capsule endoscope, and the measured value is the magnetic field measured value of the driving magnet.
Preferably, at least two magnetic sensors are provided inside the capsule endoscope to perform measurement simultaneously by the plurality of magnetic sensors to improve the accuracy of the measurement of the magnetic field of the driving magnet. As an example, the magnetic field measurement of the drive magnet may be represented as VlWhere l denotes the l-th magnetic sensor.
When at least two magnetic sensors are arranged inside the capsule endoscope, preferably, the magnetic sensors are dispersed at the inner positions of the capsule endoscope, the magnetic sensors are separated from the magnets inside the capsule endoscope and are fixed in distance, and the magnetic field measurement range of a single magnetic sensor is larger than or equal to the magnetic field intensity superposition value of the two magnets inside the capsule endoscope, so that the utilization rate and the measurement effect of the magnetic sensors are improved.
Further preferably, the magnetic sensor is a three-axis magnetic sensor, and the magnetic field strength in the three measuring axis directions can be measured, so as to improve the measuring effect of the magnetic sensor.
In step S102, the spin angle of the capsule endoscope is measured, and a measurement value of the spin angle of the capsule endoscope is obtained.
In the embodiment of the invention, after the magnetic field measurement value of the driving magnet is obtained, since the position of the capsule endoscope is a three-dimensional position, namely, the capsule endoscope comprises three degrees of freedom, and the posture of the capsule endoscope is a posture of a three-dimensional space and also comprises three degrees of freedom, in order to be able to more accurately determine the posture information (position and posture) of the capsule endoscope subsequently, namely, determine the value of 6 degrees of freedom, the spin angle of the capsule endoscope needs to be measured. The spin angle of the capsule endoscope may be measured by a spin angle measurement sensor in the capsule endoscope.
Preferably, an inertial sensor is arranged inside the capsule endoscope, and the spin angle of the capsule endoscope is measured by the inertial sensor so as to improve the measurement accuracy of the spin angle of the capsule endoscope.
Specifically, the inertial sensor includes a linear acceleration sensor and a gyroscope.
When the linear acceleration sensor in the inertial sensor is a three-axis acceleration sensor and a three-axis gyroscope, as shown in fig. 2, ax, ay, az are respectivelyThree measuring axes of a three-axis acceleration sensor are shown, omega x, omega y and omega z respectively show three measuring axes of a three-axis gyroscope, and the directions of az and omega z are H0The direction, acc is the linear acceleration of the inertial sensor, theta is the spin angle of the capsule endoscope,
is the angle between az and acc. The components of the three-axis acceleration sensor on three measuring axes are respectively:
further, the measured value of the spin angle of the capsule endoscope is determined as theta-arctan (-acc)y/accx). The formula for calculating the measured value of the spin angle of the capsule endoscope by the three-axis gyroscope in the inertial sensor is
Wherein N is the number of data measured by the triaxial gyroscope, dt is the data acquisition interval of the triaxial gyroscope, omegaziAngular rate data points for the spin of the capsule endoscope are measured for the ω z measurement axis. When the inertial sensor is used for measuring the spin angle of the capsule endoscope, the linear acceleration sensor or the gyroscope can be used independently, or the linear acceleration sensor and the gyroscope can be used for measurement together, wherein the linear acceleration sensor is a three-axis acceleration sensor, and the number of measuring axes of the gyroscope is not limited. After the measured value θ of the spin angle is obtained By calculation, a coordinate transformation relation R (θ) with respect to the measured value θ of the spin angle needs to be calculated, and the expression of R (θ) varies according to the axial direction of the magnetic sensor and the axial direction of the inertial sensor, and when the axial direction of the magnetic sensor is the same as the axial direction of the inertial sensor, that is, the axial directions Bx, By, and Bz of the magnetic sensor correspond to the axial directions ax (or ω x), ay (or ω y), and az (or wz) of the inertial sensor, respectively, the coordinate transformation relation R (θ) with respect to the measured value θ of the spin angle is obtained as follows:
In step S103, pose information of the capsule endoscope relative to the driving magnet is calculated according to the magnetic field measurement value of the driving magnet, the measurement value of the spin angle, a preset driving magnetic field model, and a preset optimization algorithm.
In the embodiment of the invention, a driving magnetic field model is constructed in advance, the magnetic field measurement error of the driving magnet is calculated according to the driving magnetic field model, the magnetic field measurement value of the driving magnet and the spin angle measurement value, the magnetic field measurement error is minimized through an optimization algorithm, and the pose information of the capsule endoscope relative to the driving magnet can be calculated.
Preferably, the distance (x) between each magnetic sensor and the center of the capsule endoscope is acquired when the driving magnetic field model is constructedl,yl,zl)TObtaining the relative permeability mu of the driving magnetrThe magnetic dipole model has higher operation efficiency in magnetic positioning operation and is very suitable for real-time positioning, and a driving magnetic field model is constructed according to the obtained parameters and the magnetic dipole model, and is expressed as follows:
When calculating the magnetic field measurement error Err of the driving magnet from the driving magnetic field model, the magnetic field measurement value of the driving magnet, and the measurement value of the spin angle, it is further preferable that the magnetic field measurement error is expressed as:
In step S104, the pose information of the capsule endoscope in the world coordinate system is determined based on the pose information of the driving magnet in the world coordinate system and the pose information of the capsule endoscope relative to the driving magnet.
In the embodiment of the invention, the pose information (position and posture) of the driving magnet in the world coordinate system is known, and when the pose information of the capsule endoscope relative to the driving magnet is obtained, the pose information of the capsule endoscope in the world coordinate system can be obtained through conversion according to the pose information of the driving magnet in the world coordinate system and the pose information of the capsule endoscope relative to the driving magnet, so that the positioning of the capsule endoscope is completed.
Preferably, a capsule endoscope model is established on a host user interface, the pose information of the capsule endoscope model is refreshed according to the pose information of the capsule endoscope obtained through positioning, and when the pose information of the next moment input by a user is received, magnetic force is generated by adjusting the position and the pose of the driving magnet, so that the capsule endoscope moves to the position and the pose in the pose information of the next moment, the human-computer interaction process of the positioning and the movement of the capsule endoscope is realized, and the user experience is improved. In addition, when the capsule endoscope moves to the position and the posture in the posture information at the next moment, the posture of the capsule endoscope is continuously adjusted according to the posture information fed back by the capsule endoscope in real time so as to balance the stress of the capsule endoscope and enable the capsule endoscope to realize suspension.
In the embodiment of the invention, the magnetic field of the driving magnet is measured, the spin angle of the capsule endoscope is measured, and the magnetic field measurement error of the driving magnet is minimized according to the driving magnetic field model, the magnetic field measurement value of the driving magnet, the measurement value of the spin angle of the capsule endoscope and the optimization algorithm to determine the pose information of the capsule endoscope, so that the influence of the driving magnetic field on the positioning accuracy is effectively avoided, and the positioning accuracy of the capsule endoscope is improved.
Example two
Fig. 3 shows a flow of implementing a positioning method for a capsule endoscope according to a second embodiment of the present invention, and for convenience of description, only the parts related to the second embodiment of the present invention are shown, which are detailed as follows:
in step S301, a first magnetic field value measured in advance is acquired.
In the embodiment of the present invention, when there is no magnetic field of the driving magnet (i.e., when the capsule endoscope is located outside the magnetic field range of the driving magnet), a first magnetic field value is measured by a magnetic sensor inside the capsule endoscope, where the first magnetic field value is a total magnetic field value of the magnet in the capsule endoscope, the geomagnetic field, and the ambient magnetic field is a magnetic field of a device (e.g., some medical devices, or a device such as a mobile phone or a computer of a user) around the capsule endoscope, and does not include the magnetic field of the driving magnet. Wherein the first magnetic field value is a fixed value when the change of the magnetic field of the surrounding environment is not considered.
In step S302, a second magnetic field value is measured by the magnetic sensor.
In the embodiment of the invention, when the capsule endoscope is driven by the driving magnet to move, the capsule endoscope is positioned in the magnetic field range of the driving magnet, and a second magnetic field value is measured by a magnetic sensor inside the capsule endoscope, wherein the second magnetic field value is the total magnetic field value of the driving magnet, the magnet inside the capsule endoscope, the geomagnetic field and the ambient magnetic field.
In step S303, a magnetic field measurement of the driving magnet is calculated according to the first magnetic field value and the second magnetic field value.
In the embodiment of the invention, the first magnetic field value is the total magnetic field value of the magnet in the capsule endoscope, the geomagnetic field and the ambient magnetic field, and the second magnetic field value is the total magnetic field value of the driving magnet, the magnet inside the capsule endoscope, the geomagnetic field and the ambient magnetic field, so that the magnetic field measurement value V of the driving magnet can be calculated by subtracting the first magnetic field value from the second magnetic field valuel。
Preferably, the magnetic field measurement V of the drive magnetlThe calculation formula of (2) is as follows:
Vl＝Vl1-Vl0wherein V isl0A first magnetic field value, V, measured for the first magnetic sensorl1A second magnetic field value measured for the ith magnetic sensor.
In step S304, the spin angle of the capsule endoscope is measured, and a measurement value of the spin angle of the capsule endoscope is obtained.
In step S305, pose information of the capsule endoscope with respect to the driving magnet is calculated according to the magnetic field measurement value of the driving magnet, the measurement value of the spin angle, a preset driving magnetic field model, and a preset optimization algorithm.
In step S306, the pose information of the capsule endoscope in the world coordinate system is determined based on the pose information of the driving magnet in the world coordinate system and the pose information of the capsule endoscope relative to the driving magnet.
In the embodiment of the present invention, the details of step S304 to step S306 can refer to the description of step S102 to step S104 in the embodiment, and are not repeated herein.
According to the embodiment of the invention, the measured values respectively measured by the magnetic sensors in the capsule endoscope are obtained when the magnetic field of the driving magnet exists and when the magnetic field of the driving magnet does not exist, the magnetic field measured value of the driving magnet is obtained through calculation, and the magnetic field measurement error of the driving magnet is minimized according to the driving magnetic field model, the magnetic field measured value of the driving magnet, the measured value of the spin angle of the capsule endoscope and the optimization algorithm, so that the pose information of the capsule endoscope is obtained, the positioning of the capsule endoscope is realized without depending on the magnetic field measured value of the magnet in the capsule endoscope, the influence of the driving magnetic field on the positioning accuracy is effectively avoided, and the positioning accuracy of the capsule endoscope.
EXAMPLE III
Fig. 4 shows a capsule endoscope 40 according to a third embodiment of the present invention, and the capsule endoscope 40 is applied to the positioning method of the capsule endoscope shown in the first and second embodiments. For convenience of explanation, only portions related to the embodiments of the present invention are shown.
In the embodiment of the present invention, the capsule endoscope 40 includes a magnetic sensor 41 provided therein, a magnet 42 in the capsule endoscope, and a spin angle measurement sensor 43. Wherein:
the magnetic sensor 41 is used for measuring a driving magnet which drives the capsule endoscope 40 to move, and obtaining a magnetic field measurement value of the driving magnet, the magnetic sensor 41 comprises a first magnetic sensor 411 and a second magnetic sensor 412, and the first magnetic sensor 411 and the second magnetic sensor 412 are arranged on a circuit board of the capsule endoscope 40 in a scattered welding mode;
the spin angle measuring sensor 43 is used to measure the spin angle of the capsule endoscope 40.
In the embodiment of the present invention, the positioning system for positioning the capsule endoscope 40 calculates the pose information of the capsule endoscope 40 with respect to the driving magnet based on the magnetic field measurement value of the driving magnet acquired from the magnetic sensor 41 and the measurement value of the spin angle acquired from the spin angle measurement sensor 43 in combination with a preset driving magnetic field model and a preset optimization algorithm, and determines the pose information of the capsule endoscope 40 in the world coordinate system based on the position information of the driving magnet in the world coordinate system and the pose information of the capsule endoscope 40 with respect to the driving magnet. The driving magnetic field model, the optimization algorithm, and the calculation process of the pose information of the capsule endoscope 40 with respect to the driving magnet may refer to the description of the corresponding step in the embodiment, and are not described herein again.
In the embodiment of the present invention, the first magnetic sensor 411 and the second magnetic sensor 412 are dispersedly welded on the circuit board of the capsule endoscope 40 to simultaneously measure the magnetic field values at different positions inside the capsule endoscope 40, and then positioning is performed according to the magnetic field measurement values of the driving magnet respectively obtained by the first sensor 411 and the second sensor 412 when the capsule endoscope 40 is positioned, so as to improve the positioning accuracy of the capsule endoscope 40. Preferably, the magnetic sensors 41 include two or more dispersed first and second sensors 411 and 412, so that the magnetic field values at different positions inside the capsule endoscope 40 are measured by the plurality of dispersed magnetic sensors 41, thereby improving the positioning accuracy of the capsule endoscope 40. For the process of obtaining the magnetic field measurement value of the driving magnet, reference may be made to the detailed description of the corresponding steps in the first embodiment and the second embodiment, which are not repeated herein.
Preferably, the first magnetic sensor 411 or the second magnetic sensor 412 is a three-axis magnetic sensor, and can measure magnetic field values in three measuring axis directions, and by combining the magnetic field values in the three measuring axis directions and the spin angle of the capsule endoscope 40 measured by the spin angle measuring sensor 43, can realize the positioning of the pose (six degrees of freedom) of the capsule endoscope 40.
Preferably, the spin angle measuring sensor 43 includes an inertial sensor by which the spin angle of the capsule endoscope 40 is measured to improve the measurement accuracy of the spin angle of the capsule endoscope 40. Furthermore, the spin angle measuring sensor 43 may also be a linear acceleration sensor and/or a gyroscope. Further, the linear acceleration sensor is a three-axis acceleration sensor.
Preferably, a radio frequency module is further disposed in the capsule endoscope 40, and the radio frequency module is connected to the first magnetic sensor 411, the second magnetic sensor 412 and the spin angle measuring sensor 43, and is configured to send out magnetic field measurement values of the driving magnetic field measured by the first magnetic sensor 411 and the second magnetic sensor 412, respectively, and send out a measurement value of the spin angle of the capsule endoscope 40 measured by the spin angle measuring sensor 43, so that a processor connected to the capsule endoscope 40 from the outside can process the measurement data in time. Besides the radio frequency module, it can be realized by other communication modules (e.g., bluetooth module) capable of realizing data communication.
In the embodiment of the invention, the capsule endoscope comprises a magnetic sensor arranged in the capsule endoscope, a magnet in the capsule endoscope and a spin angle measuring sensor, the driving magnet interacts with the magnet in the capsule endoscope to drive the capsule endoscope to move, and the capsule endoscope is positioned according to a driving magnetic field measurement value acquired by the magnetic sensor in the capsule endoscope and a spin angle measurement value acquired by the spin angle measuring sensor in the capsule endoscope by combining a preset driving magnetic field model and a preset optimization algorithm, so that the positioning effect of the capsule endoscope is improved.
Example four
Fig. 5 shows a structure of a positioning system 50 provided in a fourth embodiment of the present invention, where the positioning system 50 is used to position pose information of a capsule endoscope in a world coordinate system in the third embodiment, and for convenience of explanation, only the parts related to the third embodiment of the present invention are shown. Wherein, positioning system 50 includes: a receiver 51 and processing means 52;
a receiver 51 for acquiring magnetic field measurements of the drive magnet from the magnetic sensor and spin angle measurements from the spin angle measurement sensor;
and the processing device 52 is used for calculating the pose information of the capsule endoscope relative to the driving magnet according to the magnetic field measured value of the driving magnet acquired from the magnetic sensor and the measured value of the spin angle acquired from the spin angle measuring sensor by combining a preset driving magnetic field model and a preset optimization algorithm, and determining the pose information of the capsule endoscope in a world coordinate system according to the pose information of the driving magnet in the world coordinate system and the pose information of the capsule endoscope relative to the driving magnet.
In the embodiment of the present invention, the processing device 52 is further configured to obtain the distance between the magnetic sensor and the center of the capsule endoscope and obtain the relative permeability of the driving magnet, and construct a driving magnetic field model according to the magnetic dipole model, the distance between the magnetic sensor and the center of the capsule endoscope, and the relative permeability of the driving magnet. The specific construction process may refer to the detailed description of a corresponding step in the embodiment, and is not repeated herein.
In an embodiment of the present invention, the processing device 52 is further configured to calculate a magnetic field measurement error of the driving magnet according to the driving magnetic field model, the magnetic field measurement value of the driving magnet, and the measurement value of the spin angle; and minimizing the magnetic field measurement error of the driving magnet through an optimization algorithm to obtain the pose information of the capsule endoscope relative to the driving magnet. The detailed description of the corresponding steps in the embodiment can be referred to for the specific calculation process, and is not repeated herein.
Preferably, as shown in fig. 6, the positioning system 50 further includes the capsule endoscope 40 in the third embodiment, and the positioning system 50 is used for positioning the pose of the capsule endoscope 40 in real time, wherein the capsule endoscope 40 includes the magnetic sensor 41, the magnet 42 in the capsule endoscope, and the spin angle measurement sensor 43. The capsule endoscope 40 may be provided with a plurality of first magnetic sensors 411 and a plurality of second magnetic sensors 412.
Preferably, as shown in fig. 6, a radio frequency module is further disposed in the capsule endoscope 40, and the radio frequency module is connected to the first magnetic sensor 411, the second magnetic sensor 412 and the spin angle measuring sensor 43, and is configured to transmit the magnetic field measurement values of the driving magnetic field measured by the first magnetic sensor 411 and the second magnetic sensor 412, respectively, to the receiver 51 of the positioning system 50, and transmit the measurement values of the spin angle of the capsule endoscope 40 measured by the spin angle measuring sensor 43 to the receiver 51 of the positioning system 50, so as to assist the positioning system 50 in positioning the capsule endoscope 40. Besides the radio frequency module, it can be realized by other communication modules (e.g., bluetooth module) capable of realizing data communication.
In the embodiment of the invention, a receiver in the positioning system receives a magnetic field measurement value of a driving magnet and a measurement value of a spin angle of the capsule endoscope, which are sent by the capsule endoscope, and a processing device determines the pose information of the capsule endoscope in a world coordinate system according to the magnetic field measurement value of the driving magnet and the measurement value of the spin angle of the capsule endoscope by combining a preset driving magnetic field model, a preset optimization algorithm and the pose information of the driving magnet in the world coordinate system, so that the positioning of the capsule endoscope is realized, and the positioning accuracy of the capsule endoscope is improved.
EXAMPLE five
Fig. 7 shows a structure of a positioning system for positioning a capsule endoscope according to a fifth embodiment of the present invention, and for convenience of explanation, only the parts related to the embodiment of the present invention are shown, including:
and the magnetic field measuring unit 71 is used for measuring the magnetic field of the driving magnet for driving the capsule endoscope to move through the magnetic sensor to obtain the magnetic field measured value of the driving magnet.
In the embodiment of the invention, the capsule endoscope is internally provided with the magnetic sensor and the magnet in the capsule endoscope, and the driving magnet outside the capsule endoscope drives the capsule endoscope to move through interaction with the magnet in the capsule endoscope. In the process of driving the capsule endoscope to move, the capsule endoscope needs to be positioned in real time, and as the relative pose between the magnet in the capsule endoscope and the driving magnet is different when the pose of the capsule endoscope changes, the magnetic field at the position of the capsule endoscope also changes. Therefore, when the capsule endoscope is positioned, the magnetic field intensity of the driving magnet is measured by all the magnetic sensors in the capsule endoscope, and the measured value is the magnetic field measured value of the driving magnet.
Preferably, at least two magnetic sensors are provided inside the capsule endoscope to perform measurement simultaneously by the plurality of magnetic sensors to improve the accuracy of the measurement of the magnetic field of the driving magnet. As an example, the magnetic field measurement of the drive magnet may be represented as VlWhere l denotes the l-th magnetic sensor.
When at least two magnetic sensors are arranged inside the capsule endoscope, preferably, the magnetic sensors are dispersed at the inner positions of the capsule endoscope, the magnetic sensors are separated from the magnets inside the capsule endoscope and are fixed in distance, and the magnetic field measurement range of a single magnetic sensor is larger than or equal to the magnetic field intensity superposition value of the two magnets inside the capsule endoscope, so that the utilization rate and the measurement effect of the magnetic sensors are improved.
Further preferably, the magnetic sensor is a three-axis magnetic sensor, and the magnetic field strength in the three measuring axis directions can be measured, so as to improve the measuring effect of the magnetic sensor.
And the spin measuring unit 72 is used for measuring the spin angle of the capsule endoscope and obtaining the measured value of the spin angle of the capsule endoscope.
In the embodiment of the invention, after the magnetic field measurement value of the driving magnet is obtained, since the position of the capsule endoscope is a three-dimensional position, namely, the capsule endoscope comprises three degrees of freedom, and the posture of the capsule endoscope is a three-dimensional posture and also comprises three degrees of freedom, in order to be able to determine the posture information (position and posture) of the capsule endoscope subsequently, namely, the value of 6 degrees of freedom can be determined, the spin angle of the capsule endoscope needs to be measured. The measurement of the spin angle of the capsule endoscope can be realized by a spin angle measuring sensor in the capsule endoscope.
Preferably, an inertial sensor is arranged inside the capsule endoscope, and the spin angle of the capsule endoscope is measured by the inertial sensor so as to improve the measurement accuracy of the spin angle of the capsule endoscope.
Specifically, the inertial sensor includes a linear acceleration sensor and a gyroscope.
When the linear acceleration sensor in the inertial sensor is a three-axis acceleration sensor and a three-axis gyroscope, as shown in fig. 2, ax, ay, az respectively represent three measurement axes of the three-axis acceleration sensor, ω x, ω y, ω z respectively represent three measurement axes of the three-axis gyroscope, and the directions of az and ω z are H0The direction, acc is the linear acceleration of the inertial sensor, theta is the spin angle of the capsule endoscope,
is the angle between az and acc. The components of the three-axis acceleration sensor on three measuring axes are respectively:
further, the measured value of the spin angle of the capsule endoscope is determined as theta-arctan (-acc)y/accx). The formula for calculating the measured value of the spin angle of the capsule endoscope by the three-axis gyroscope in the inertial sensor is
Wherein N is the number of data measured by the triaxial gyroscope, dt is the data acquisition interval of the triaxial gyroscope, omegaziAngular rate data points for the spin of the capsule endoscope are measured for the ω z measurement axis. When the inertial sensor is used for measuring the spin angle of the capsule endoscope, the inertial sensor can be used for measuring the spin angle of the capsule endoscope independently or by combining a three-axis acceleration sensor and a three-axis gyroscope, wherein the three-axis acceleration sensor is used as the linear acceleration sensor, and the number of measuring axes of the gyroscope is not limited. After the measured value θ of the spin angle is obtained By calculation, a coordinate transformation relation R (θ) with respect to the measured value θ of the spin angle needs to be calculated, and the expression of R (θ) varies according to the axial direction of the magnetic sensor and the axial direction of the inertial sensor, and when the axial direction of the magnetic sensor is the same as the axial direction of the inertial sensor, that is, the axial directions Bx, By, and Bz of the magnetic sensor correspond to the axial directions ax (or ω x), ay (or ω y), and az (or wz) of the inertial sensor, respectively, the coordinate transformation relation R (θ) with respect to the measured value θ of the spin angle is obtained as follows:
And the relative pose calculation unit 73 is used for calculating pose information of the capsule endoscope relative to the driving magnet according to the magnetic field measurement value of the driving magnet, the spin angle measurement value, the preset driving magnetic field model and the preset optimization algorithm.
In the embodiment of the invention, a driving magnetic field model is constructed in advance, the magnetic field measurement error of the driving magnet is calculated according to the driving magnetic field model, the magnetic field measurement value of the driving magnet and the spin angle measurement value, the magnetic field measurement error is minimized through an optimization algorithm, and the pose information of the capsule endoscope relative to the driving magnet can be calculated. Wherein the construction of the driving magnetic field model and the calculation of the pose information of the capsule endoscope relative to the driving magnet (including the calculation and minimization process of the magnetic field measurement error) are executed by a processing device in the positioning system.
Preferably, the driving magnetic field is constructedIn modeling, the distance (x) between each magnetic sensor and the center of the capsule endoscope is obtainedl,yl,zl)TObtaining the relative permeability mu of the driving magnetrThe magnetic dipole model has higher operation efficiency in magnetic positioning operation and is very suitable for real-time positioning, so that a driving magnetic field model is constructed according to the obtained parameters and the magnetic dipole model, and the driving magnetic field model is expressed as follows:
When calculating the magnetic field measurement error Err of the driving magnet from the driving magnetic field model, the magnetic field measurement value of the driving magnet, and the measurement value of the spin angle, it is further preferable that the magnetic field measurement error is expressed as:
And the capsule pose determining unit 74 is used for determining the pose information of the capsule endoscope in the world coordinate system according to the pose information of the driving magnet in the world coordinate system and the pose information of the capsule endoscope relative to the driving magnet.
In the embodiment of the invention, the pose information (position and posture) of the driving magnet in the world coordinate system is known, and when the pose information of the capsule endoscope relative to the driving magnet is obtained, the pose information of the capsule endoscope in the world coordinate system can be obtained through conversion according to the pose information of the driving magnet in the world coordinate system and the pose information of the capsule endoscope relative to the driving magnet, so that the positioning of the capsule endoscope is completed.
Preferably, a capsule endoscope model is established on a host user interface, the pose information of the capsule endoscope model is refreshed according to the pose information of the capsule endoscope obtained through positioning, and when the pose information of the next moment input by a user is received, magnetic force is generated by adjusting the position and the pose of the driving magnet, so that the capsule endoscope moves to the position and the pose in the pose information of the next moment, the human-computer interaction process of the positioning and the movement of the capsule endoscope is realized, and the user experience is improved. In addition, when the capsule endoscope moves to the position and the posture in the posture information at the next moment, the posture of the capsule endoscope is continuously adjusted according to the posture information fed back by the capsule endoscope in real time so as to balance the stress of the capsule endoscope and enable the capsule endoscope to realize suspension.
Preferably, as shown in fig. 8, the magnetic field measurement unit 71 includes:
a first magnetic field value obtaining unit 711, configured to obtain a first magnetic field value measured in advance, where the first magnetic field value is a total magnetic field value of a magnet inside the capsule endoscope, a geomagnetic field, and a magnetic field of a surrounding environment without being affected by the driving magnet;
a second magnetic field value measuring unit 712, configured to obtain a second magnetic field value through measurement by the magnetic sensor, where the second magnetic field value is a total magnetic field value of the driving magnet, the magnet inside the capsule endoscope, the geomagnetic field, and the magnetic field of the surrounding environment; and
a magnetic field value calculating unit 713, configured to calculate a magnetic field measurement value of the driving magnet according to the first magnetic field value and the second magnetic field value.
In the embodiment of the invention, when the magnetic field of the driving magnet is absent (namely, when the capsule endoscope is positioned outside the magnetic field range of the driving magnet), a first magnetic field value is measured by a magnetic sensor inside the capsule endoscope, the first magnetic field value is the total magnetic field value of the magnet in the capsule endoscope, the geomagnetic field and the ambient magnetic field, and the ambient magnetic field is the magnetic field of the equipment around the capsule endoscope and does not include the magnetic field of the driving magnet. Wherein the first magnetic field value is a fixed value when the change of the magnetic field of the surrounding environment is not considered.
In the embodiment of the invention, when the capsule endoscope is driven by the driving magnet to move, the capsule endoscope is positioned in the magnetic field range of the driving magnet, and a second magnetic field value is measured by a magnetic sensor inside the capsule endoscope, wherein the second magnetic field value is the total magnetic field value of the driving magnet, the magnet inside the capsule endoscope, the geomagnetic field and the ambient magnetic field.
In the embodiment of the invention, the first magnetic field value is the total magnetic field value of the magnet in the capsule endoscope, the geomagnetic field and the ambient magnetic field, and the second magnetic field value is the total magnetic field value of the driving magnet, the magnet inside the capsule endoscope, the geomagnetic field and the ambient magnetic field, so that the magnetic field measurement value V of the driving magnet can be calculated by subtracting the first magnetic field value from the second magnetic field valuel。
Preferably, the magnetic field measurement V of the drive magnetlThe calculation formula of (2) is as follows:
Vl＝Vl1-Vl0wherein V isl0A first magnetic field value, V, measured for the first magnetic sensorl1A second magnetic field value measured for the ith magnetic sensor.
Preferably, as shown in fig. 8, the relative pose calculation unit 73 includes:
an error calculation unit 731 for calculating a magnetic field measurement error of the driving magnet according to the driving magnet model, the magnetic field measurement value of the driving magnet, and the measurement value of the spin angle; and
an error minimization unit 732, configured to minimize the magnetic field measurement error of the driving magnet through an optimization algorithm, and obtain pose information of the capsule endoscope relative to the driving magnet.
In the embodiment of the present invention, details of the error calculation unit 731 and the error minimization unit 732 are already described in the relative pose calculation unit 73, and are not described again.
Preferably, the positioning system further comprises:
the parameter acquisition unit is used for acquiring the distance between the magnetic sensor and the center of the capsule endoscope and acquiring the relative magnetic permeability of the driving magnet; and
and the magnetic field model building unit is used for building a driving magnetic field model according to the magnetic dipole model, the distance between the magnetic sensor and the center of the capsule endoscope and the relative magnetic permeability of the driving magnet.
In the embodiment of the invention, the magnetic field of the driving magnet is measured, the spin angle of the capsule endoscope is measured, and the magnetic field measurement error of the driving magnet is minimized according to the driving magnetic field model, the magnetic field measurement value of the driving magnet, the measurement value of the spin angle of the capsule endoscope and the optimization algorithm to determine the pose information of the capsule endoscope, so that the influence of the driving magnetic field on the positioning accuracy is effectively avoided, and the positioning accuracy of the capsule endoscope is improved.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (16)
1. A method of positioning a capsule endoscope, wherein a magnetic sensor and a magnet in the capsule endoscope are provided inside the capsule endoscope, the method comprising:
acquiring a first magnetic field value measured in advance, wherein the first magnetic field value is the total magnetic field value of a magnet inside the capsule endoscope, a geomagnetic field and a surrounding magnetic field under the condition that the first magnetic field value is not influenced by a driving magnet for driving the capsule endoscope to move;
measuring by the magnetic sensor to obtain a second magnetic field value, wherein the second magnetic field value is the total magnetic field value of the driving magnet, the magnet inside the capsule endoscope, the geomagnetic field and the magnetic field of the surrounding environment;
calculating a magnetic field measurement value of the drive magnet according to the first magnetic field value and the second magnetic field value;
measuring the spin angle of the capsule endoscope to obtain a measurement value of the spin angle of the capsule endoscope;
calculating the pose information of the capsule endoscope relative to the driving magnet according to the magnetic field measurement value of the driving magnet, the spin angle measurement value, a preset driving magnetic field model and a preset optimization algorithm;
and determining the pose information of the capsule endoscope in the world coordinate system according to the pose information of the driving magnet in the world coordinate system and the pose information of the capsule endoscope relative to the driving magnet.
2. The method of claim 1, wherein the step of calculating pose information of the capsule endoscope relative to the driver magnets comprises:
calculating a magnetic field measurement error of the driving magnet according to the driving magnetic field model, the magnetic field measurement value of the driving magnet and the measurement value of the spin angle;
and minimizing the magnetic field measurement error of the driving magnet through the optimization algorithm to obtain the pose information of the capsule endoscope relative to the driving magnet.
3. The method of claim 1, wherein prior to the step of measuring the magnetic field by a magnetic sensor on a drive magnet that drives movement of the capsule endoscope, the method further comprises:
acquiring the distance between the magnetic sensor and the center of the capsule endoscope and acquiring the relative magnetic permeability of the driving magnet;
and constructing the driving magnetic field model according to the magnetic dipole model, the distance between the magnetic sensor and the center of the capsule endoscope and the relative magnetic permeability of the driving magnet.
4. The method of claim 1, wherein at least two of the magnetic sensors are disposed within the capsule endoscope, wherein the magnetic sensors are three-axis magnetic sensors.
5. The method of claim 1, wherein an inertial sensor is provided inside the capsule endoscope, the inertial sensor being used to measure a spin angle of the capsule endoscope.
6. A capsule endoscope, comprising: a magnetic sensor disposed in the capsule endoscope, a magnet in the capsule endoscope, and a spin angle measurement sensor;
the magnetic sensor is used for acquiring a first magnetic field value measured in advance, the first magnetic field value is the total magnetic field value of a magnet inside the capsule endoscope, a geomagnetic field and a surrounding magnetic field under the influence of a driving magnet which drives the capsule endoscope to move, a second magnetic field value is obtained through measurement of the magnetic sensor, the second magnetic field value is the total magnetic field value of the driving magnet, the magnet inside the capsule endoscope, the geomagnetic field and the surrounding magnetic field, and the magnetic field measurement value of the driving magnet is calculated according to the first magnetic field value and the second magnetic field value;
the magnetic sensors comprise a first magnetic sensor and a second magnetic sensor, and the first magnetic sensor and the second magnetic sensor are arranged on a circuit board in the capsule endoscope in a scattered welding mode;
the spin angle measuring sensor is used for measuring the spin angle of the capsule endoscope, so that the positioning system calculates the pose information of the capsule endoscope relative to the driving magnet according to the magnetic field measured value of the driving magnet acquired from the magnetic sensor and the measured value of the spin angle acquired from the spin angle measuring sensor by combining a preset driving magnetic field model and a preset optimization algorithm, and determines the pose information of the capsule endoscope in a world coordinate system according to the pose information of the driving magnet in the world coordinate system and the pose information of the capsule endoscope relative to the driving magnet.
7. The capsule endoscope of claim 6, wherein the first magnetic sensor or the second magnetic sensor is a three-axis magnetic sensor.
8. A capsule endoscope according to claim 6 or 7, wherein said spin angle measurement sensor comprises an inertial sensor.
9. The capsule endoscope of claim 6, wherein the magnetic sensors comprise two or more discrete first or second magnetic sensors.
10. A positioning system for positioning pose information of the capsule endoscope of any one of claims 6-9 in a world coordinate system, the capsule endoscope further comprising a spin angle measurement sensor; the magnetic sensors comprise a first magnetic sensor and a second magnetic sensor, and the first magnetic sensor and the second magnetic sensor are arranged on a circuit board in the capsule endoscope in a scattered welding mode; the spin angle measuring sensor is used for measuring the spin angle of the capsule endoscope;
the positioning system includes: a receiver and a processing device;
the receiver for obtaining magnetic field measurements of the drive magnet from the magnetic sensor and measurements of the spin angle from the spin angle measurement sensor;
the processing device is used for calculating the pose information of the capsule endoscope relative to the driving magnet according to the magnetic field measured value of the driving magnet acquired from the magnetic sensor and the measured value of the spin angle acquired from the spin angle measuring sensor by combining a preset driving magnetic field model and a preset optimization algorithm, and determining the pose information of the capsule endoscope in a world coordinate system according to the pose information of the driving magnet in the world coordinate system and the pose information of the capsule endoscope relative to the driving magnet.
11. The positioning system of claim 10, wherein the capsule endoscope comprises a radio frequency module, the first magnetic sensor, the second magnetic sensor, and the spin angle measurement sensor are coupled to the radio frequency module, the first magnetic sensor and the second magnetic sensor each transmit a magnetic field measurement of the drive magnet to the receiver via the radio frequency module, and the spin angle measurement sensor transmits the spin angle measurement to the receiver via the radio frequency module.
12. The positioning system of claim 10 or 11, wherein the processing device is further configured to calculate a magnetic field measurement error of the drive magnet based on the drive magnetic field model, the magnetic field measurement of the drive magnet, and the measurement of the spin angle; and minimizing the magnetic field measurement error of the driving magnet through the optimization algorithm to obtain the pose information of the capsule endoscope relative to the driving magnet.
13. The positioning system of claim 10 or 11, wherein the processing device is further configured to obtain a distance of the magnetic sensor from a center of the capsule endoscope and obtain a relative permeability of the drive magnet; and constructing the driving magnetic field model according to the magnetic dipole model, the distance between the magnetic sensor and the center of the capsule endoscope and the relative magnetic permeability of the driving magnet.
14. A positioning system for positioning a capsule endoscope, wherein a magnetic sensor and a magnet in the capsule endoscope are provided inside the capsule endoscope, the positioning system comprising:
the capsule endoscope comprises a first magnetic field value acquisition unit, a second magnetic field value acquisition unit and a control unit, wherein the first magnetic field value acquisition unit is used for acquiring a first magnetic field value measured in advance, and the first magnetic field value is the total magnetic field value of a magnet inside the capsule endoscope, a geomagnetic field and a surrounding magnetic field under the condition that the first magnetic field value is not influenced by a driving magnet for driving the capsule endoscope to move;
the second magnetic field value measuring unit is used for measuring a second magnetic field value through the magnetic sensor, wherein the second magnetic field value is the total magnetic field value of the driving magnet, the magnet inside the capsule endoscope, the geomagnetic field and the ambient magnetic field;
the magnetic field value calculation unit is used for calculating the magnetic field measurement value of the driving magnet according to the first magnetic field value and the second magnetic field value;
the spin measuring unit is used for measuring the spin angle of the capsule endoscope and obtaining the measured value of the spin angle of the capsule endoscope;
the relative pose calculation unit is used for calculating pose information of the capsule endoscope relative to the driving magnet according to the magnetic field measurement value of the driving magnet, the spin angle measurement value, a preset driving magnetic field model and a preset optimization algorithm; and
and the capsule pose determining unit is used for determining the pose information of the capsule endoscope in the world coordinate system according to the pose information of the driving magnet in the world coordinate system and the pose information of the capsule endoscope relative to the driving magnet.
15. The positioning system according to claim 14, wherein the relative pose calculation unit includes:
an error calculation unit for calculating a magnetic field measurement error of the driving magnet according to the driving magnetic field model, the magnetic field measurement value of the driving magnet, and the spin angle measurement value; and
and the error minimization unit is used for minimizing the magnetic field measurement error of the driving magnet through the optimization algorithm to obtain the pose information of the capsule endoscope relative to the driving magnet.
16. The positioning system of claim 14, further comprising:
the parameter acquisition unit is used for acquiring the distance between the magnetic sensor and the center of the capsule endoscope and acquiring the relative magnetic permeability of the driving magnet; and
and the magnetic field model building unit is used for building the driving magnetic field model according to the magnetic dipole model, the distance between the magnetic sensor and the center of the capsule endoscope and the relative magnetic permeability of the driving magnet.
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| WO2020252940A1 (en) * | 2019-06-17 | 2020-12-24 | 深圳硅基智控科技有限公司 | Magnetic control device of capsule endoscope and method for controlling movement of capsule endoscope in tissue cavity |
| CN111184497B (en) | 2020-04-08 | 2020-07-17 | 上海安翰医疗技术有限公司 | Capsule endoscope control method and system |
| CN111870211A (en) * | 2020-07-28 | 2020-11-03 | 北京信息科技大学 | Three-dimensional endoscope with instrument pose navigation function and navigation method thereof |
| CN112741586B (en) * | 2020-12-23 | 2022-04-01 | 武汉大学 | Position acquisition method based on capsule endoscopy human body internal position acquisition system |
| CN115104999A (en) * | 2021-03-18 | 2022-09-27 | 深圳硅基智控科技有限公司 | Capsule endoscope system and capsule endoscope magnetic positioning method thereof |
| CN113238291B (en) * | 2021-06-21 | 2023-11-17 | 福建世新机器人科技有限公司 | Geomagnetic vector real-time estimation and separation method based on magnetic component positioning tracking |
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| CN114668362B (en) * | 2022-03-18 | 2022-11-11 | 元化智能科技(深圳)有限公司 | Positioning system and device of wireless capsule endoscope and computer equipment |
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| CN107348931A (en) * | 2017-05-27 | 2017-11-17 | 重庆金山医疗器械有限公司 | A kind of capsule endoscope spatial attitude assay method, system and device |
| CN108827133A (en) * | 2018-06-15 | 2018-11-16 | 北京理工大学 | A method of detecting mobile magnetic source pose |
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| CN109620104A (en) | 2019-04-16 |
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