2.2. Practical Implementation

Except for a small low-cost blower (DF501512SH FAN, Vordas, Shenzen, China; 12 V; 5 × 5 × 1.5 cm) employed to generate the airflow, we used recycled materials to assemble the device in the diagram of Figure 1. As shown in Figure 2, the ice container was made using two conventional disposable 8 L plastic bottles for drinking water: the upper part of one of the bottles was cut and the bottom of the other bottle was cut and, after making several small holes in it, it was used as the platform to sustain the ice and to allow the melted ice water to drop. The isolating chamber (18 × 22 × 27 cm, internal dimensions) was made using pieces of expanded polystyrene (4 cm width) which is a material usually employed in the building and packaging industries and is therefore widely available (Figure 2). This material was also employed for embedding the external pipe to conduct the refrigerated air to the infant: 20 cm in length, an internal square section of 1 cm per side, and an external rectangular section (4 × 12 cm) (Figure 2). The pipe ended with a vertical, short (3 cm) cylindrical tube having a 12 mm internal diameter (not visible in Figure 2). A 25 cm long piece of hose (1.5 cm in diameter) inside the chamber connected its airflow entrance with the upper part of the water compartment. The length of the tube section inside the water chamber was short enough to avoid it being submersed in water when the ice melts.

Construction of the simple, low-cost assembly used for the proof-of-concept testing. (A) Eight-liter plastic bottle of drinking water. (B) Compartment for ice/water made from the lower part of one bottle, piece to separate the ice and water made by cutting and drilling the base of another bottle, and piece of hose. (C) Assembled ice/water compartment. (D) Isolating chamber (expanded polystyrene) with blower and hose (upper wall open). Glue was used to seal the wall attachments to avoid air leaks. (E) Compartment for ice/water placed within the insulating chamber and loaded with ice. (F) Setting with closed chamber ready to be used with the testing infant manikin.