PROBLEM TO BE SOLVED: To provide a detector for coming off of indwelling needle which ensures to determine optically that the catheter is in a blood vessel when it is inserted and determines optically whether the needle comes off during transfusion to make user know the status.SOLUTION: The detector for coming off of indwelling needle includes an inner needle hub 40 having an inner needle inserted into the catheter 12, an emitting part 3 to emit the light into the vessel from the inner needle hub and the tip of the catheter, a connector part 11 one end of which is connected to the catheter and the other end of which is removably mounted with the emitting part 3 after the inner needle is removed, an emission driving part 4, an emission receiving part 88 to receive light emitted from the tip of the catheter when the catheter is inserted into the vessel to transfuse medicinal solution through catheter, and a controller 5 which determines that the tip of the catheter is off from the vessel by receiving signal from the emission receiving part and comparing the thresholds of the receiving signal and the predetermined receiving signal.COPYRIGHT: (C)2010,JPO&INPIT【課題】カテーテルを血管内に刺入する際に血管内に入っていることを光学的に確実に検出でき、輸液中に針抜け状態が発生しているかどうかを光学的に検出して容易に確実に知ることができる留置針の針抜け検出装置を提供する。【解決手段】カテーテル12内に挿入される内針を有する内針ハブ40と、光を内針ハブとカテーテルの先端から血管内に照射する発光部3と、内針を抜去した後に一端部がカテーテルに接続され他端部には発光部3が着脱可能に装着されるコネクタ部11と、発光駆動部4と、カテーテルを血管内に刺し入れる場合とカテーテルを通じて薬液を輸液する場合にカテーテルの先端から照射される光を受光する受光部88と、受光部から受光信号を受け、受光信号と予め定めた受光信号のしきい値とを比較してカテーテルの先端が血管から抜けていると判断する制御部5を備える。【選択図】図1
