Method and system for determining orientation of capsule endoscope

Patent metadata

Field	Value
Publication number	US-11819320-B2
Application number	US-202117199360-A
Country	US
Kind code	B2
Filing date	Mar 11, 2021
Priority date	Mar 11, 2020
Publication date	Nov 21, 2023
Grant date	Nov 21, 2023

Abstract

The present invention discloses a method and system for determining orientation of a capsule endoscope. An external magnetic field is provided outside the capsule endoscope, and an internal magnetic field is provided inside the capsule endoscope. Magnetic field data is obtained according to the external magnetic field and the internal magnetic field, and acceleration data of the capsule endoscope is obtained. When the polarization direction of the external magnetic field is horizontal, the orientation information of the capsule endoscope is obtained according to the acceleration data. When the polarization direction of the external magnetic field is non-horizontal, the orientation information of the capsule endoscope is obtained according to the acceleration data and the magnetic field data.

First claim

What is claimed is:

1. A method for determining orientation of a capsule endoscope, comprising:
providing an external magnetic field outside the capsule endoscope;
providing an internal magnetic field inside the capsule endoscope;
obtaining magnetic field data according to the external magnetic field and the internal magnetic field;
obtaining acceleration data of the capsule endoscope; and
obtaining the orientation information of the capsule endoscope according to the acceleration data when a polarization direction of the external magnetic field is horizontal, and
obtaining the orientation information of the capsule endoscope according to the acceleration data and magnetic field data when the polarization direction is non-horizontal,
wherein when the polarization direction of the external magnetic field is non-horizontal, the step of obtaining orientation information of the capsule endoscope comprises:
obtaining a tilt angle of the capsule endoscope to ground according to the acceleration data;
obtaining a distance between the external magnet and the capsule endoscope and a vector angle between a direction vector of the external magnet and a direction vector of the capsule endoscope according to the magnetic field data;
obtaining a magnetic field direction of the external magnet in a geodetic coordinate system according to the distance;
obtaining the orientation information of the capsule endoscope according to the tilt angle of the capsule endoscope to ground, the vector angle and the magnetic field direction.

2. The method of claim 1 , wherein an external magnet provides the external magnetic field, the method further comprising:
obtaining the polarization direction of the external magnet according to position coordinates and tilt angle of the external magnet.

3. The method of claim 2 , wherein when the polarization direction of the external magnetic field is horizontal, the step of obtaining orientation information of the capsule endoscope comprises:
obtaining a horizontal orientation of the capsule endoscope based on a direction of a horizontal polarization component of the external magnet; and obtaining a tilt angle of the capsule endoscope relative to a reference ground based on the acceleration data.

4. The method of claim 1 , wherein when a gravity line of the capsule endoscope coincides with a gravity line of the external magnet, a first formula is used to calculate the magnetic field direction of the external magnet in the geodetic coordinate system; and wherein when the gravity line of the capsule endoscope does not coincide with the gravity line of the external magnet, a second formula is used to calculate the magnetic field direction of the external magnet in the geodetic coordinate system,
the first formula is:

(

a
,
b
,
c

)

=

1

1
+

3
⁢
cos
⁢

α
2

⁢

(

sin
⁢
αcos
⁢
β

,

-

sin

⁢
αsin
⁢
β

,

cos
⁢
α

)

;

the second formula is:

(

a
,
b
,
c

)

=

1

1
+

3
⁢
cos
⁢

α
2

⁢

(

sin
⁢
αcos
⁢
β

,

-

sin

⁢
αsinβ

,

cos
⁢
α

)

;

wherein (a, b, c) represents the magnetic field direction of the external magnet in the geodetic coordinate system, a is the tilt angle of the external magnet, β is an angle between the polarization direction of the external magnet and the x-axis, B x , B y and B z respectively represent the x-axis, y-axis, and z-axis components of the magnetic field generated by the external magnet at the position of the magnetic field sensor.

5. The method of claim 1 , wherein obtaining the distance and the vector angle comprises:
obtaining a first sub-magnetic field data representing the internal magnetic field;
obtaining a second sub-magnetic field data representing the internal magnetic field and the external magnetic field;
obtaining a third sub-magnetic field data representing the external magnetic field according to the first sub-magnetic field data and the second sub-magnetic field data;
obtaining the distance between the external magnet and the capsule endoscope according to the third sub-magnetic field data; and
obtaining the vector angle between the direction vector of the external magnet and the direction vector of the capsule endoscope according to the second sub-magnetic field data and the third sub-magnetic field data.

6. The method of claim 1 , wherein obtaining the magnetic field data according to the external magnetic field and the internal magnetic field comprises:
obtaining a magnetic field value according to the internal magnetic field and the external magnetic field;
obtaining th

Assignees

• Ankon Medical Tech Shanghai Co Ltd
• Anx Ip Holding Pte Ltd

Inventors

• Duan Xiaodong
• Wang Qingqing

Classifications

• A61B5/062 Primary

  using magnetic field · CPC title

• A61B1/00009

  of image signals during a use of endoscope · CPC title

• A61B1/041 Primary

  Capsule endoscopes for imaging · CPC title

• G16H20/40

  relating to mechanical, radiation or invasive therapies, e.g. surgery, laser therapy, dialysis or acupuncture · CPC title

• A61B1/045

  Control thereof · CPC title