POSITION DETECTING SYSTEM AND POSITION DETECTING METHOD

• US 20110012594A1
• Filed: 06/29/2010
• Published: 01/20/2011
• Est. Priority Date: 11/21/2008
• Status: Active Grant

• Current Assignee: Olympus Corporation
• Original Assignee: Olympus Medical Systems Corporation (Olympus Corporation)
• Inventors: SATO, Ryoji, KIMURA, Atsushi, KAWANO, Hironao, CHIBA, Atsushi
• Granted Patent: US 8,049,503 B2
• Time in Patent Office: Days
• US Class Current: 324/309
• CPC Class Codes: A61B 1/00016 using wireless means
• CPC Class Codes: A61B 1/00036 Means for power saving, e.g. sleeping mode
• CPC Class Codes: A61B 1/00158 using magnetic field
• CPC Class Codes: A61B 1/041 Capsule endoscopes for imaging
• CPC Class Codes: A61B 1/042 characterised by a proximal camera, e.g. a CCD camera
• CPC Class Codes: A61B 5/061 Determining position of a probe within the body employing means separate from the probe, e.g. sensing internal probe position employing impedance electrodes on the surface of the body A61B1/00158 takes precedence
• CPC Class Codes: A61B 5/065 Determining position of the probe employing exclusively positioning means located on or in the probe, e.g. using position sensors arranged on the probe
• CPC Class Codes: A61B 5/073 Intestinal transmitters

Abstract

A system includes a body-insertable apparatus disposed while introduced in a subject in a detection space, and an external apparatus disposed on the outside of the subject. The body-insertable apparatus includes a first switch for connecting/interrupting a resonance circuit and an oscillation circuit or a ground line. The external apparatus includes a drive coil driving unit for outputting a drive signal having the resonance frequency; a drive coil for generating the drive magnetic field in the detection space in accordance with the drive signal; and a second switch for connecting/interrupting the drive coil driving unit and the drive coil. The second switch connects the drive coil driving unit and the drive coil when the first switch is off, and disconnects them when the first switch is on. The resonance circuit generates the resonance magnetic field in accordance with the induction signal or the drive magnetic field.

Claims

1. A position detecting system comprising:

a body-insertable apparatus disposed in a state where it is introduced in a subject in a detection space; and

an external apparatus disposed on the outside of the subject,

wherein the body-insertable apparatus comprises

an oscillation circuit that outputs an induction signal of a resonance frequency;

a resonance circuit that generates a resonance magnetic field having the resonance frequency in accordance with the induction signal output from the oscillation circuit or a drive magnetic field having the resonance frequency generated in the detection space, and is connected between the oscillation circuit and a ground line; and

a first switch that connects and interrupts the resonance circuit and the oscillation circuit or the ground line,

the external apparatus comprises

a drive coil driving unit that outputs a drive signal having the resonance frequency;

a drive coil that generates the drive magnetic field in the detection space in accordance with the drive signal;

a second switch that connects and interrupts the drive coil driving unit and the drive coil;

a magnetic field sensor that detects the resonance magnetic field; and

a position deriving unit that derives position information of the body-insertable apparatus by using information of the resonance magnetic field detected by the magnetic field sensor,

the second switch connects the drive coil driving unit and the drive coil when the first switch is in an off state, and disconnects the drive coil driving unit and the drive coil when the first switch is in an on state, and

the resonance circuit generates the resonance magnetic field in accordance with the induction signal or the drive magnetic field.

2. The position detecting system according to claim 1, wherein

the external apparatus comprises

a signal intensity detecting unit that detects signal intensity of a detection signal detected by the magnetic field sensor;

and

a second switch control unit that controls an on/off state of the second switch based on the signal intensity detected by the signal intensity detecting unit.

3. The position detecting system according to claim 1, wherein

the body-insertable apparatus comprises:

an internal power source that supplies power to the inside of the body-insertable apparatus; and

a first switch control unit that controls the first switch in accordance with voltage level of a power source voltage output from the internal power source.

4. The position detecting system according to claim 1, wherein

the external apparatus comprises:

a switching coil that generates a switching magnetic field in the detection space; and

a switching coil driving unit that supplies a signal for generating the switching magnetic field to the switching coil, and

the first switch is a magnetic reed switch which is turned on/off according to the switching magnetic field.

5. The position detecting system according to claim 1, wherein

the external apparatus comprises a control signal transmitting unit that transmits a control signal for controlling an on/off state of the first switch to the body-insertable apparatus, and

the body-insertable apparatus comprises:

a control signal receiving unit that receives the control signal; and

a first switch control unit that controls an on/off state of the first switch based on the switch signal.

6. The position detecting system according to claim 5, wherein

the control signal transmitting unit comprises

a control coil that forms a control magnetic field in the detection space;

and

a control coil driving unit that supplies a signal for generating the control magnetic field to the control coil, and

the control signal receiving unit comprises

a magnetic reed switch that is turned on/off according to the control magnetic field; and

a first switch control unit that controls the on/off state of the first switch based on a signal output from the magnetic reed switch.

7. The position detecting system according to claim 6, wherein the control coil driving unit supplies a signal for generating the control magnetic field in a predetermined pattern to the control coil.

8. The position detecting system according to claim 1, wherein

the body-insertable apparatus comprises a magnetic field generating unit that generates a magnetic field, and

the external apparatus comprises

a guidance coil that forms a guidance magnetic field which acts on the magnetic field generating unit in the detection space;

and

a guidance coil driving unit that supplies a signal for generating the guidance magnetic field to the guidance coil.

9. The position detecting system according to claim 4, wherein

the body-insertable apparatus comprises a magnetic field generating unit that generates a magnetic field,

the external apparatus comprises

a guidance coil that forms a guidance magnetic field which acts on the magnetic field generating unit in the detection space;

and

a guidance coil driving unit that supplies a signal for generating the guidance magnetic field to the guidance coil, and

the guidance coil or the drive coil is used as the switching coil.

10. The position detecting system according to claim 6, wherein

the body-insertable apparatus comprises a magnetic field generating unit that generates a magnetic field,

the external apparatus comprises

a guidance coil that forms a guidance magnetic field which acts on the magnetic field generating unit in the detection space;

and

a guidance coil driving unit that supplies a signal for generating the guidance magnetic field to the guidance coil, and

the guidance coil or the drive coil is used as the control coil.

11. The position detecting system according to claim 1, wherein the external apparatus comprises an averaging unit that averages the position information.

12. The position detecting system according to claim 11, wherein the averaging unit changes a parameter of position information to be averaged, between an on state and an off state of the second switch.

13. The position detecting system according to claim 1, wherein the external apparatus comprises an averaging unit that averages information of the resonance magnetic field.

14. The position detecting system according to claim 13, wherein the averaging unit sets different parameters of information of the resonance magnetic field to be averaged for the case where the second switch is in the on state and the case where the second switch is in the off state.

15. The position detecting system according to claim 1, wherein the position deriving unit derives the position information of the body-insertable apparatus from information obtained by eliminating the information of the drive magnetic field from the magnetic field information included in a detection signal detected by the magnetic field sensor.

16. The position detecting system according to claim 1, wherein the position deriving unit derives the position information of the body-insertable apparatus from information obtained by eliminating information of unnecessary magnetic field generated when the drive coil is excited by the resonance magnetic field from the magnetic field information included in a detection signal detected by the magnetic field sensor in a state where the second switch is in an on state.

17. The position detecting system according to claim 1, wherein

the body-insertable apparatus comprises

an imaging unit that images the inside of the subject to capture an image;

and

an image transmitting unit that transmits the image captured by the imaging unit to the external apparatus, and

the external apparatus comprises

an image receiving unit that receives the image transmitted from the image transmitting unit; and

a display unit that displays the image received by the image receiving unit together with the position information.

18. A position detecting system comprising:

a body-insertable apparatus disposed in a state where it is introduced in a subject in a detection space; and

an external apparatus disposed on the outside of the subject,

wherein the body-insertable apparatus comprises

an oscillating means for outputting an induction signal of a resonance frequency;

a resonance means for generating a resonance magnetic field having the resonance frequency in accordance with the induction signal output from the oscillating means or a drive magnetic field having the resonance frequency generated in the detection space, the resonance means being connected between the oscillating means and a ground line; and

a first switching means for connecting and interrupting the resonance means and the oscillating means or the ground line,

the external apparatus comprises;

a drive signal outputting means for outputting a drive signal having the resonance frequency;

a drive magnetic field generating means for generating the drive magnetic field in the detection space in accordance with the drive signal;

a second switching means for connecting and interrupting the drive signal outputting means and the drive magnetic field generating means;

a magnetic field detecting means for detecting the resonance magnetic field; and

a position deriving means for deriving position information of the body-insertable apparatus by using information of the resonance magnetic field detected by the magnetic field detecting means,

the second switching means connects the driving signal output means and the drive magnetic field generating means when the first switching means is in an off state, and disconnects the drive signal outputting means and the drive magnetic field generating means when the first switching means is in an on state, and

the resonance means generates the resonance magnetic field in accordance with the induction signal or the drive magnetic field.

19. A position detecting method for detecting position in a subject of a body-insertable apparatus including a resonance circuit that generates a resonance magnetic field spontaneously or being induced by an external magnetic field, the position detecting method comprising:

a resonance magnetic field intensity detecting step of detecting intensity of the resonance magnetic field;

a resonance magnetic field intensity determining step of determining whether the magnetic field intensity detected at the resonance magnetic field intensity detecting step is equal to or larger than a predetermined value;

an external magnetic field generating step, when the magnetic field intensity is smaller than the predetermined value, of generating the external magnetic field;

a resonance magnetic field detecting step of detecting a resonance magnetic field spontaneously generated by the resonance circuit or a resonance magnetic field generated by being induced by the external magnetic field generated at the external magnetic field generating step; and

a position deriving step of deriving position information indicative of a position in the subject of the body-insertable apparatus based on the resonance magnetic field detected at the resonance magnetic field detecting step.

20. The position detecting method according to claim 19, wherein

the position deriving step includes

a position information storing step of storing the position information derived in the position deriving step by an amount of predetermined number of times;

and

a position information averaging step of averaging the position information of the amount of the predetermined number of times stored in the position information storing step, and

the position information indicative of the position in the subject of the body-insertable apparatus is derived based on the averaged position information.