Method for automatic, continuous blood sampling with remote alarm for clogged catheters.

An inexpensive blood sampling system is described that includes a remote alarm triggered by a decrease in rate of blood withdrawal. Additional modifications include design of a reliable sampling catheter and of a method for quickly and atraumatically replacing clogged catheters. This system has been used to collect continuous, integrated blood samples every 15 min for up to 72 h from cows. The alarm system is also useful for monitoring any flow in which minimum rate is critical, e.g., for column chromatography.