Abstract: A reception system includes a reception circuit, an antenna element, a cable, a switching circuit, and a control unit. The switching circuit can perform switching between a first connection state in which the reception circuit, the antenna element, and the cable are electrically connected to each other and a second connection state in which the reception circuit and the cable are electrically connected to each other but the antenna element is not electrically connected to the cable. The control unit controls the switching circuit such that the first connection state is obtained in a first time period and the second connection state is obtained in a second time period.

Abstract: A receiving antenna system includes: a receiving antenna including: an antenna element configured to receive a radio signal transmitted from a medical device introduced into a subject; and a base material on which the antenna element is mounted, the base material including a first base material, and a second base material; and a holder attached to the subject and configured to house the receiving antenna, wherein the antenna element is mounted on the first base material or the second base material, one of the first base material and the second base material has higher effective permittivity than effective permittivity of another one of the first base material and the second base material, and the first base material, the antenna element and the second base material are arranged in this order from a subject side.

Abstract: A position detection device includes: a region acquiring unit that acquires a region where at least two of spheres with receiving antennas as centers and distances between each receiving antenna and a capsule endoscope as radii overlap with one another; an orientation estimating unit that estimates orientations of the capsule endoscope at points in the region based on positional relationships between the points and the receiving antennas, and received strength of signals received by the receiving antennas; and a position determination unit that determines the position of the capsule endoscope based on the positions of the points and the orientations, wherein the position determination unit calculates theoretical values of the received strength at the points, acquires measured values of the received strength at the receiving antennas, and detects a point having a minimum error between the theoretical value and the measured value as the position of the capsule endoscope.

Abstract: A position detection apparatus includes: a distance calculation unit configured to calculate a first distance between each of a plurality of receiving antennas and the capsule endoscope based on each reception strength of a signal received by the plurality of receiving antennas, a total distance calculation unit configured to calculate a total sum of distances from spherical surfaces inside a region where at least three or more spheres out of a plurality of spheres are overlapped, each of the plurality of spheres having a center at each of the plurality of receiving antennas and having a radius of the first distance, and a position determination unit configured to detect, as the position of the capsule endoscope, a position where the total sum of distances from the spherical surfaces is minimum.