Respiratory rate

The respiratory rate is the rate at which breathing occurs. This is usually measured in breaths per minute and is set, and controlled by the respiratory centre. The respiratory rate is the rate at which breathing occurs. This is usually measured in breaths per minute and is set, and controlled by the respiratory centre. The respiratory rate in humans is measured when a person is at rest and involves counting the number of breaths for one minute by counting how many times the chest rises. A fibre-optic breath rate sensor can be used for monitoring patients during a magnetic resonance imaging scan. Respiration rates may increase with fever, illness, or other medical conditions. Inaccuracies in respiratory measurement have been reported in the literature. One study compared respiratory rate counted using a 90-second count period, to a full minute, and found significant differences in the rates.. Another study found that rapid respiratory rates in babies, counted using a stethoscope, were 60–80% higher than those counted from beside the cot without the aid of the stethoscope. 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. Various other methods to measure respiratory rate are commonly used, including impedance pneumography, and capnography which are commonly implemented in patient monitoring. In addition novel techniques for automatically monitoring respiratory rate using wearable sensors are in development, such as estimation of respiratory rate from the electrocardiogram, photoplethysmogram and accelerometry signals. For humans, the typical respiratory rate for a healthy adult at rest is 12–18 breaths per minute. The respiratory center sets the quiet respiratory rhythm at around two seconds for an inhalation and three seconds exhalation. This gives the lower of the average rate at 12 breaths per minute. Average resting respiratory rates by age are: Respiratory minute volume is the volume of air which is inhaled (inhaled minute volume) or exhaled (exhaled minute volume) from the lungs in one minute.