Respiratory rate may be generally thought of as the number of breaths we take per minute. When we breathe, air is inhaled into the lungs, where oxygen is filtered out and made available to the blood vessels. At the same time, the lungs filter carbon dioxide from the blood, which is removed from the body as we breathe out.
This process occurs so instinctively that we don’t consciously think about it. However, breathing rate is a rich source of insights as it is triggered by autonomic brain processes responsible for physiological arousal.
As we encounter startling stimuli we adjust our breathing rate and as we get stressed and agitated, our breathing rate changes. Monitoring respiratory rates can provide valuable insights across many sectors in both academic and commercial research.
Measuring respiration rate
In the past, respiratory rate was measured using manual approaches. When the participant or patient was at rest, the researcher or practitioner would count the number of breaths per minute.
Subsequent studies have found this approach to be somewhat lacking. Although this method is widely used, there is a large margin of error with different individuals perceiving different numbers of breaths!
You can imagine how easy it might be for inconsistencies to creep in, as well as how time consuming it could be! In a research setting obtaining data needs to be as efficient as possible for the sake of both researcher and participant so manual recording is both impractical and inconvenient.
A variety of devices are now available which allow you to measure respiratory rate and incorporate it into your research. Taking advantage of this new technology is a great way of obtaining more sophisticated data.
In this piece we will take a look at pneumographic devices, which are the most widely used means of measuring respiration rate in research settings.
These devices measure the force of chest movements during respiration using a range of methods. Many require the use of a transducer belt and an amplifier
a) Transducer Belt
The belt is worn by the participant and is sensitive to any changes in thoracic (between the neck and abdomen) or abdominal circumference.
Often, where the belt is worn will be determined by whether the subject breathes primarily with the stomach or chest.
If using a belt ensure that it is fitted closely to the body. It also helps to have as little movement as possible while measuring the subject’s respiration rate, since too much movement can cause noise in the data.
If you do observe noise in the data, it helps to differentiate between whether this is physiological or due to movement by the participant.
Using software with real time capability can help with this. For example, if you observe an abnormality but simultaneously observe the participant turn in their seat, you know to ignore any strange data output.
Some devices will have different amplifier settings depending on research needs. It’s useful to have these different settings available so look out for them when selecting a product.
A physiological study looking at the effect of a particular exercise program, for example, will have vastly different requirements to a sedentary market research study.
The amplifier stabilizes the signal received by the transducer and ensures it is clean and centered. Check out this link for a more detailed overview of using this technology.
A wide range of software allows you to analyze pneumographic data in great detail, one of which is the iMotions platform.
Incorporating the simple concept of breathing into your research may seem simple, but it can give you a really fascinating insight into your participant’s emotional and psychological processes.
Stress and emotional arousal are both correlated with respiration rate, so investigating this factor can give you another angle on how your participants are responding to the chosen stimuli.
In addition, iMotions software allows you to easily incorporate measurement of respiratory effort with other biometric sensors. It can also export this synchronised data to your data analysis program of choice.
Imagine being able to combine respiratory data with EEG and GSR information – the potential is mind-blowing, and best of all, already possible with the help of the iMotions platform.