Résumé
The common negative pressure drainage bottle used in the vacuum sealing drainage (VSD) cannot quantitative and automatically cut off. Excessive drainage damages the negative pressure source, causes drainage interruption, so once drainage was continuously performed, medical staff need to closely observe drainage bottle calibration. It was also important to known whether there was a large amount of fresh blood sucked out during continuous drainage because it could lose too much blood. To solve these two problems, we designed a kind of negative pressure drainage device, which volume was constant, with the function of automatic cutting off continuous drainage. It can not only prevent drainage fluid flowing back to the negative pressure source and cause drainage interruption, but also prevent massive blood loss from continued drainage after the hemorrhage. We could benefit from this device, which possess many advantages, such as simple structure, security and reliability. It is worthy promoting in the clinical work.