PROBLEM TO BE SOLVED: To provide a dialyzer that enables blood recirculation to be grasped safely and accurately during dialysis treatment.SOLUTION: In a dialyzer having a blood purifier composed of a dialysis membrane disposed between a blood flow path and a dialysis fluid flow path an artery side blood circuit is connected to the upstream side of the blood flow path of the blood purifier, a vein side blood circuit is connected to the downstream side of the blood flow path of the blood purifier, a dialysis fluid supply line is connected to the upstream side of the dialysis fluid flow path of the blood purifier, a dialysis fluid drain line is connected to the downstream side of the dialysis fluid flow path of the blood purifier, and measuring means for measuring blood parameters which are characteristic values of blood is provided to the artery side blood circuit. A predetermined amount of the dialysis fluid is caused to flow into the blood flow path through the dialysis membrane, the blood parameters are acquired from the measuring means, and a change in the blood parameters by the flowing of the dialysis fluid into the blood flow path is detected.SELECTED DRAWING: Figure 1【課題】透析治療中に血液再循環を安全かつ正確に把握できる透析装置を提供する。【解決手段】血液流路と透析液流路との間に設けられた透析膜からなる血液浄化器を有する透析装置であって、血液浄化器の血液流路上流側に動脈側血液回路が接続され、血液浄化器の血液流路下流側に静脈側血液回路が接続され、血液浄化器の透析液流路上流側に透析液供給ラインが接続され、血液浄化器の透析液流路下流側に透析液排液ラインが接続され、血液の特性値である血液パラメータを測定する測定手段が動脈側血液回路に設けられ、透析膜を通して血液流路へと所定量の透析液を流入させ、測定手段から血液パラメータを取得して血液流路への透析液の流入による血液パラメータの変化を検出する透析装置。【選択図】図１
