Capsule endoscope apparatus

Abstract

A signal processing circuit of an external device includes a CPU and a memory which are not shown. A program for estimating at least one of the position and orientation of a capsule endoscope on the basis of strength signals received through respective antennas is installed in the signal processing circuit. A single-core coil to generate a magnetic field is arranged in the capsule endoscope. The generated magnetic field is detected by a plurality of coils arranged outside a body, whereby a distance that the capsule endoscope has traveled can be obtained with accuracy. This arrangement controls image-capture timing to reliably capture images necessary for a diagnosis and prevent unnecessary image capture.

1 . A capsule endoscope apparatus comprising an image capturing unit for capturing an image in a body to transmit the image by radio and a receiving unit for receiving the image transmitted by radio from the image capturing unit to record the image, the apparatus further comprising:
 a transmitting unit having a plurality of first antennas arranged at different positions outside the body to transmit a signal having a specific magnitude through each antenna;   an estimating unit for receiving the signals generated from the antennas through a second antenna disposed in the image capturing unit to estimate at least one of the position and orientation of the image capturing unit on the basis of the received signals; and   a control unit for controlling image capture by the image capturing unit using information regarding at least one of the position and orientation obtained by the estimating unit.   
     
     
         2 . The capsule endoscope apparatus according to  claim 1 , wherein
 the control unit includes:   a distance calculating unit for calculating a distance that the image capturing unit has traveled on the basis of a plurality of positions of the image capturing unit obtained by the estimating unit; and   an image-capture control unit for controlling image capture by the image capturing unit on the basis of the distance.   
     
     
         3 . The capsule endoscope apparatus according to  claim 2 , wherein
 the distance calculating unit includes a unit for calculating a predicted distance on the basis of the plurality of positions of the image capturing unit obtained by the estimating unit.   
     
     
         4 . The capsule endoscope apparatus according to  claim 3 , wherein the predicted distance is calculated using an approximation function derived from the plurality of positions of the image capturing unit obtained by the estimating unit. 
     
     
         5 . The capsule endoscope apparatus according to  claim 2 , wherein
 the control unit includes:   an orientation-change calculating unit for calculating a change in orientation of the image capturing unit on the basis of a plurality of orientations obtained by the estimating unit; and   an image-capture control unit for controlling image capture by the image capturing unit on the basis of the distance and the change in orientation.