A drip infusion warning system.

: We have developed a drip infusion warning system for hospital and care facility use. In general, two kinds of infusion sets are used, which have drop factors of either 20 or 60. (A drop factor is the number of drops to deliver 1 ml of infusion solution.) When an infusion set having a 20 drop factor is used, the number of drops per drip is adjusted to 20. If an infusion set has a drop factor of 60, then the infusion volume rate becomes three times as much. This may result in legal consequences if the patient is injured. In this study, a drip infusion warning system detects whether the infusion is a 20 or a 60 drop factor. The system consists of two electrodes, one wrapped around the infusion supply polyvinyl-chloride tube, and another one around the drip chamber. The electrical impedance between two electrodes is changed by the growth and fall of each drop of fluid. The drop growth length especially changes, depending on the type of infusion set used. Therefore, the two types of infusion sets can be identified by monitoring the drop length. Our warning system detects whether the infusion set used corresponds to a 20 or 60 drop factor, so the system can reduce human errors.