A flow metering insert (10) for a drip chamber (50) is provided that is suitable for use in intravenous administration. The insert comprises: a primary liquid flow channel with an inlet, an outlet, and a flow-resistant passage between the inlet and the outlet; and a flow indicating channel in communication with the primary liquid flow channel between the inlet and the flow-resistant passage. The flow-resistant passage provides a resistance to liquid flow such that liquid is forced into the flow indicating channel and reaches a height proportional to the rate of liquid flow through the primary liquid flow channel. The flow-resistant passage and the flow indicating channel are at least partially defined by one or more first recesses and/or channels in the insert such that the flow-resistant passage and the flow indicating channel are formed between the insert and a wall of the drip chamber when the insert is inserted into the drip chamber.

A portable air flow meter fabricated using a 3D printer. A nozzle cover, a fixing cover, and a handle are formed integrally with a cylindrical housing in which a multi-nozzle for measuring an air flow is installed. The cylindrical housing is fabricated using a 3D printer. Fabrication costs are reduced, and a fabrication period is reduced. The portable air flow meter has superior portability due to light weight, and is effective in terms of usability.

A flow meter for intravenous liquids comprising a vertical inlet passage (2), a parallel indicating chamber (9), a U shaped flow-resistant liquid passage (6), and an exit chamber (11). Liquid to be dispensed enters the inlet passage (2) via inlet (5) and moves down the passage to a junction with both the U shaped flow-resistant passage (6), and the indicator passage. From the junction, the liquid rises up the indicator passage to a height proportional to the flow rate set by an external flow meter, and also through the flow resistant passage, which has an outlet (8) that delivers the liquid to the exit chamber (11) and from there to a patient through an outlet (12). The meter may be formed by an assembly of two injection molded components, thus reducing manufacturing costs.

A flow meter for intravenous liquids comprising a vertical inlet passage (2), a parallel indicating chamber (9), a U shaped flow-resistant liquid passage (6), and an exit chamber (11). Liquid to be dispensed enters the inlet passage (2) via inlet (5) and moves down the passage to a junction with both the U shaped flow-resistant passage (6), and the indicator passage. From the junction, the liquid rises up the indicator passage to a height proportional to the flow rate set by an external flow meter, and also through the flow resistant passage, which has an outlet (8) that delivers the liquid to the exit chamber (11) and from there to a patient through an outlet (12). The meter may be formed by an assembly of two injection moulded components, thus reducing manufacturing costs.