The invention relates to a passage detection device of an
indwelling catheter, in particular to a self-
recovery device of detecting a pipeline passage by a diaphragm type
blood withdrawal method. Thedevice is characterized in that an elastic film is hermetically connected to a
piston cylinder, and a cavity body in the
piston cylinder is divided into two parts of space by the elastic film, whereinone part of the space is communicated between the
indwelling catheter and a liquid source pipeline in a
vein blood vessel, and the other part of the space provides a deformation space for the elasticfilm; the elastic film is connected with a driving connecting piece, the elastic film elastically deforms in the
piston cylinder by pressing the driving connecting piece, negative pressure is formedbetween the
indwelling catheter and the liquid source pipeline in the
vein blood vessel, and whether blood flows back at the indwelling
catheter or not is detected through the formed negative pressure; and the detected elastic film returns to an initial state after releasing the driving connecting piece. The device can be connected with the indwelling
catheter for a long time, is used for checkingwhether the pipeline is unobstructed or not before infusion, reduces the individual difference problem of manual operation while simplifying the operation of withdrawing blood, and obviously improvesthe efficiency and quality of
nursing operation of the indwelling
catheter before infusion.