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how to make a manometre?

Manometer with iron wire

Materials:

• 50 centimetres of transparent plastic tube, with a diameter of 8 to 10 millimetres;

• A block of foam rubber of about 3 by 3 centimetres, which may function as a nasal ‘button’;

• 35 centimetres of thin iron wire;

• A magic marker;

• A drinking glass.

Push the iron wire up through the plastic tube. Make sure the ends of the tube are free of wire. Cut the foam rubber into a conical shape and make a hole in the length of the cone, which is a little smaller than the diameter of the tube. Push the foam rubber onto the end of the tube, broad side first. Bend the tube with iron wire into a U-shape. At approximately one and a half centimetres above the curve, place indication lines on the vertical part of the tube, on the end where the foam rubber has been placed. These should be horizontal lines, placed at every half centimetre. Fill the tube with fluid, up to the first indication line. The manometer is ready to use. The manometer may be placed in a drinking glass so that the fluid does not escape and the hands are kept free to perform the polite yawning technique.

Keep in mind that the iron wire may start to rust after some time. A ‘fresh’ manometer should therefore (and also for hygienic reasons) be constructed for each new patient.

A nasal button may be the best way to keep outside air out of the nose when using a manometer. An original nasal button is, however, used by Otolaryngologists and is not easy to come by or copy. The end of the plastic tube may be placed in the nostril without a nasal button, if it would not be so unpleasant and at times irritating and would make it difficult to close off the nostril around the end of the tube. Using a piece of foam rubber is a compromise between an original nasal button and just leaving the tube as it is. The foam rubber protects the nostril from unpleasantness and even injury, but the orthonasal airflow to the nose is more diffuse. It is therefore of great importance to close off the opening of the nostril around the tube, obviously without actually closing off the tube itself.