A study on the change of droplet volume by the increase of flow rate

Abstract

Abstract: Drip-control type infusion pumps cause a flow rate error when the volume of the droplet dropping in the drip chamber changes. Therefore, the purpose of this study is to accurately measure the volume of one droplet as the flow rate increases. For measurement of droplet volume, a droplet bypassing device was prototyped. In the case of a 20 drop/mL drip nozzle, a volume error of + 7.6% occurred at a flow rate of 500 mL/min, compared to the theoretical volume of 50.0 mm3. In the case of a 60 drop/mL drip nozzle, a volume error of − 17.4% occurred at a flow rate of 300 mL/min, compared to the theoretical volume of 16.7 mm3. Moreover, the standard deviation of the measured value of the droplet volume increased as the flow rate increased. It was shown that even with proper use of the infusion set, significant flow rate errors can occur depending on the flow rate settings. Therefore, it is considered that the drip-control type infusion pump needs to be controlled by correcting the volume change due to the increase in the flow rate. Graphic Abstract: The volume of one droplet intermittently dropped from the drip nozzle using a droplet bypass device was accurately measured. The change in droplet volume with increasing flow rate was shown [Figure not available: see fulltext.].