Device for retaining blood in a vein

摘要

The device has a sleeve (16) fastened at a body part e.g. arm, including a vein and an artery. The sleeve includes pneumatic chambers (20a, 20b), which exert pressure on the body part by volume change such that the vein and/or the artery is closed. A sensor (24) e.g. pressure sensor, directly or indirectly contacts the body part during fastening the sleeve at the body part. The sensor detects blood flow through the artery and delivers a sensor signal (25). A value of the sensor signal is based on the blood flow. The sensor signal controls a display unit (36) e.g. LED.