Page 29 - Olfaction regained_Flipbook-subtitles

Instead of water a coloured fluid can also be used in order to enhance visibility. However, this may cause colouring of the manometer tubes, which subsequently might cause a decreased visibility. The nasal button attached to the end of the flexible tube must be held against one nostril, keeping it closed off from the outside air. It is important to check whether the opening in the nasal button is free in the nasal cavity and not occluded by the nasal septum or nasal concha. A finger must close the other nostril, since nasal airflow will otherwise be generated there as well. This airflow will reduce the displacement of the fluid in the manometer. When the nostril is closed correctly, the polite yawning technique can be carried out. This is done correctly when the fluid in the manometer moves towards the nose of the patient. The passage of the nostrils, also called nasal cycle, changes in most humans every couple of hours. At a certain point in time, one nostril is more open than the other (Hasegawa and Kern, 1977; Eccles, 1978; Broek and Feenstra, 1995). Therefore, it is advisable to try both nostrils when using the manometer in order to identify the most open one, which should consequently be used during practice. Obviously, closing one of the nostrils is of course only necessary when practicing with the manometer. When the polite yawning technique is used normally to smell this will not be necessary. Figure 11. Correct movement of the fluid in the manometer. At first, when practicing the most important objective is to have the fluid move in the right direction. Then, it is important that this movement is repeated frequently, the fluid should fluctuate up and down regularly and evenly. Subsequently, the emphasis is on enlarging the magnitude of replacement of the fluid with the lowest possible effort. Finally, the patient should be able to carry out the movement correctly without using the manometer, and automatically. Only then, will the patient benefit optimally from the polite yawning 28