A fibre-optic breath rate sensor can be used for monitoring patients during a magnetic resonance imaging scan.
[citation needed] Similar results are seen with animals when they are being handled and not being handled—the invasiveness of touch apparently is enough to make significant changes in breathing.
One study found that only 33% of people presenting to an emergency department with an oxygen saturation below 90% had an increased respiratory rate.
It has also been reported that factors such as crying, sleeping, agitation and age have a significant influence on the respiratory rate.
[citation needed] As a result of these and similar studies the value of respiratory rate as an indicator of serious illness is limited.