Position detection apparatus and medical-device-position detection system

Abstract

A position detection apparatus and a medical-device-position detection system that have improved position detection accuracy are provided by setting high amplification for the position detection apparatus. The position detection apparatus includes a circuit that has at least one embedded coil ( 10 a ) and that is provided inside an object ( 10 ) to be detected; a first magnetic-field generating unit ( 11 ) for generating a first magnetic field in the region where the embedded coil ( 10 a ) is disposed; a magnetic-field detecting unit ( 5, 12 ) for detecting an induced magnetic field generated at the embedded coil ( 10 a ) by the first magnetic field; and a second magnetic-field generating unit ( 23 ) for generating a second magnetic field having a phase substantially opposite to the phase of the first magnetic field.

1 . A medical-device-position detection system comprising:
 a medical device including a circuit having at least one embedded coil, and a magnet;   a first magnetic-field generating unit for generating a first magnetic field;   a magnetic-field detecting unit for detecting an induced magnetic field excited at the embedded coil by the first magnetic field; and   a second magnetic-field generating unit for generating a second magnetic field having a phase substantially opposite to the phase of the first magnetic field,   wherein the second magnetic-field generating unit is configured to generate a third magnetic field for controlling the position and orientation of the magnet included in the medical device.   
     
     
         2 . The medical-device-position detection system according to  claim 1 , wherein the magnetic-field detecting unit and the second magnetic-field generating unit are arranged on substantially the same flat surface. 
     
     
         3 . The medical-device-position detection system according to  claim 1 , wherein an object to be detected is a capsule medical device. 
     
     
         4 . The medical-device-position detection system according to  claim 3 , wherein the capsule medical device includes a container for holding a medication to be administgered to a subject. 
     
     
         5 . The medical-device-position detection system according to  claim 1 , wherein the second magnetic-field generating unit is provided with a moving mechanism for moving a position of at least one of a mutually-induced-magnetic-field generating coil for generating a mutually induced magnetic field by the first magnetic field and a second magnetic-field generating coil positioned in the vicinity of the magnetic-field detecting unit. 
     
     
         6 . The medical-device-position detection system according to  claim 5 , wherein the moving mechanism is configured to move the position of the mutually-induced-magnetic-field generating coil so as to minimize the intensity of a magnetic-field-intensity signal being output from the magnetic-field detecting unit and being associated with a combined magnetic field of the first magnetic field and the second magnetic field. 
     
     
         7 . The medical-device-position detection system according to  claim 1 , wherein an object to be detected is a tubular medical device. 
     
     
         8 . The medical-device-position detection system according to  claim 7 , wherein the tubular medical device is a catheter or an endoscope. 
     
     
         9 . The medical-device-position detection system according to  claim 7 , wherein the embedded coil is provided substantially at a tip of the tubular medical device. 
     
     
         10 . The medical-device-position detection system according to  claim 7 , wherein the embedded coil is provided at an intermediate section of the tubular medical device. 
     
     
         11 . The medical-device-position detection system according to  claim 1 , wherein
 the second magnetic-field generating unit is positioned in the vicinity of the first magnetic-field generating unit and includes a mutually-induced-magnetic-field generating coil for generating a mutually induced magnetic field by the first magnetic field and a second magnetic-field generating coil positioned in the vicinity of the magnetic-field detecting unit, and   the mutually-induced-magnetic-field generating coil and the second magnetic-field generating coil are electrically connected in series.   
     
     
         12 . The medical-device position detection system according to  claim 1 , wherein the second magnetic-field generating unit includes a mutually-induced-magnetic-field generating coil for generating a mutually induced magnetic field by the first magnetic field. 
     
     
         13 . The medical-device-position detection system according to  claim 11 , wherein the mutually-induced-magnetic-field generating coil and the first magnetic-field generating unit are arranged on substantially the same flat surface. 
     
     
         14 . A medical-device-position detection system comprising:
 a medical device including a circuit having at least one embedded coil, and a magnet;   a first magnetic-field generating unit for generating a first magnetic field;   a magnetic-field detecting unit for detecting an induced magnetic field excited at the embedded coil by the first magnetic field; and   a second magnetic-field generating unit for generating a second magnetic field having a phase substantially opposite to the phase of the first magnetic field,   wherein the position and orientation of the magnet included in the medical device is controlled based on the second magnetic field generated by the second magnetic-field generating unit.