This information pertains to both the Spirometer and the Go Direct Spirometer.
For safety precautions, a bacterial filter must always be used with the spirometer, and each student must use their own bacterial filter. Students must never share bacterial filters.
The bacterial filter is placed on the inlet of the spirometer and is designed to protect the user during an inhalation. During an inhalation, air is brought across the spirometer head and then into the filter. During an exhalation, the air goes through the filter that then goes through the spirometer. So in this case, the spirometer head is protected from the exhaled air from the student.
Each student must use their own filter to maintain sterility of the spirometer. If you have the students ‘share’ filters then they will be breathing in material from the previous student during an inhalation. Students can write their name on their filter and then use this filter for a period of days. That filter should last them for a month or so but should be stored in a sealed plastic bag.
Students that are feeling sick should NOT use the spirometer.
Bacterial filters can not be sterilized.
See How effective is the bacterial filter for the spirometer? if you need more information on the bacterial filter or if you need to clean the flow head of the Spirometer. The Go Direct Spirometer does not have a removable flow head, and therefore can not be sterilized.