Abstract: A connector (50) includes a tubular member (52) and a base tube (58). A light-guiding tube (60) is drawn out from the base tube (58) toward the opposite side to the tubular member (52). An adapter (1) includes: a first connecting portion (10) that can be connected to and disconnected from a light source device (70); a second connecting portion (20) that can be connected to and disconnected from the connector (50); and a light-guiding member (30) that guides light emitted from the light source device (70) to a proximal end surface (61) of the tube (60).

Abstract: A tube distal end position detection system (1) includes a light source device (50) that emits light, a hollow tube (10) having a flow path (11) that allows a liquid to flow through, a connector (20) provided at a base end of the tube so as to allow light from the light source device to be incident on an end surface (12) at the base end of the tube, and a light emitting portion (30) provided at the distal end of the tube. Light from the light source device passes through the tube and is emitted from the light emitting portion and transmitted to the body surface.

Abstract: In the estimation method, MRI indexes (such as ADC and FA) are estimated based on a scattering coefficient ?s? of a measurement site B or a parameter having a correlation with the scattering coefficient ?s?, the scattering coefficient ?s? being obtained by a near-infrared spectroscopy based on a detection result of near-infrared light made incident on the measurement site B and propagated inside the measurement site B.