System for detecting position of distal end of medical tube

A medical tube distal end position detection system for detecting a position of a distal end of a tube inserted into a patient, the system comprising:

• a light source device that emits light;
• a hollow tube having a flow path that allows a liquid to flow therethrough;
• a connector provided at a base end of the tube so as to allow the light from the light source device to be incident on an end surface at the base end of the tube;
• and
• a light emitting portion provided at the distal end of the tube,
• wherein the tube comprises a three-layer structure of an inner layer, an outer layer, and an intermediate layer provided between the inner layer and the outer layer, in which the intermediate layer has a higher refractive index than the inner layer and the outer layer, and the inner layer, the outer layer, and the intermediate layer are each made of resin,
• the system is configured so that the light from the light source device is allowed to pass through the intermediate layer of the tube and be emitted from the light emitting portion, and the light from the light emitting portion is allowed to be transmitted to a body surface,
• wherein the light emitting portion includes a refractive member that refracts light emerging from the tube,
• the refractive member is arranged coaxially with the tube, and
• an outer diameter of the refractive member is larger than an outer diameter of the tube.