TECHNICAL FIELD

The present invention relates to a fluid measuring apparatus configured to measure information about a fluid by irradiating the fluid with light.

BACKGROUND ART

For this type of apparatus, there is known an apparatus configured to irradiate a fluid with light and to receive scattered light, thereby measuring a fluid concentration, a flow volume, a flow velocity, and the like. For example, Patent Literature 1 discloses a technology/technique in which a blood flowing in an artificial dialysis apparatus is irradiated with light to measure a blood concentration (or a hematocrit value) and a blood flow volume.

CITATION LIST

Patent Literature

Patent Literature 1: Japanese Patent No. 5586476

SUMMARY OF INVENTION

Technical Problem

In the artificial dialysis apparatus, a blood collected from a patient flows in a tube by a power of a pump; however, the blood may temporarily flow backward in the tube because of characteristics of the pump. As a result, the measurement using the light may not be accurately performed.

In the aforementioned Patent Literature 1, there is no description about a backflow of the blood. Thus, if the backflow of the blood occurs, the blood concentration and the blood flow volume cannot be accurately measured, which is technically problematic.

The above is an example of problems to be solved by the present invention. It is therefore an object of the present invention to provide a fluid measuring apparatus configured to accurately measure information about a fluid.

Solution to Problem

The above object of the present invention can be achieved by a first fluid measuring apparatus provided with: an irradiating device configured to irradiate a fluid with light; a light receiving device configured to receive light scattered by the fluid; a detecting device configured to detect a backflow of the fluid on the basis of a received light signal of the light receiving device; and a calculating device configured to calculate estimated concentration information indicating a concentration of the fluid, on the basis of a detection result of the detecting device and the received light signal of the light receiving device.

The above object of the present invention can be achieved by a second fluid measuring apparatus provided with: an irradiating device configured to irradiate a fluid with light; a light receiving device configured to receive light scattered by the fluid; a detecting device configured to detect that a change amount of received light intensity indicated by a received light signal of the light receiving device is greater than or equal to a predetermined value; and a calculating device configured to calculate estimated concentration information indicating a concentration of the fluid, on the basis of a detection result of the detecting device and the received light signal of the light receiving device.

