Making a Respiratory Belt

The respiratory belt can be made from materials that are available on the consumer market. The belt has one inelastic and one elastic part. The inelastic part is made from curtain cloth, with hook and loop fasteners sewed on it. The elastic part is made from electrolycra and two parts of elastic. The resistance of electrolycra varies depending on how much it is stretched. For this reason, electrolycra is a useful component for measuring the stretch of the respiration belt, by measuring how the chest expands and contracts with inhalation and exhalation. Images of the respiratory belt are shown in the figures below. The electrolycra part is cut from a larger piece of the fabric. The approximate size of the electrolycra part is 6×1.5 cm. The approximate size of the elastic parts is 6×2 cm. The electrolycra can be cut in two directions, which will result in different profiles for how the resistance depends on the stretch of the fabric. In our experience, the best result is achieved when the electrolycra is cut in the fiber direction. This is illustrated in the bottom figure below with a red cut out from a larger piece of electrolycra fabric.

Arduino1_ed

The elastic part of the respiratory belt. In the middle the electrolycra (gray fabric) is surrounded by elastics (black material).

Arduino2_ed

The entire respiratory belt.

Fabric

A red cutout from a larger fabric of electrolycra.