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When defining respiration rate we say that it is the number of breaths a person takes per minute. We can easily count the number of breaths when a person is at rest by counting the number of times his or her chest may rise in a one minute. The normal range for an adult will be between 12 to 16 breaths per minute. You should always ensure that your patient is not having difficulty breathing. There can be changes in the respiration rate due to illness Hopkins:2018
There are different normal ranges for children and adults. Children have a higher respiratory rate than adults Eldridge,2018.

Table showing the different ranges of respiratory rates:
Infant (1 to 12 months) 30-60 breaths per minute
Toddler (1-2 years) 24-40 breaths per minute
Pre-schooler (3-5 years) 22-34 breaths per minute
School-age child (6-12 years) 18-30 breaths per minute
Adolescent (13-17 years) 12-16 breaths per minute
Adults 12-16 breaths per minute

Abnormal respiratory rates are very common in people .There are five main ones: 1.Apnea 2.Dyspnea 3.Tachypnea 4.Hyperpnea 5.Bradypnea

These can be caused by other medical conditions such as fever, asthma, dehydration, sleep conditions and alcohol.
There are four methods used to measure respiratory rate: Physical chest counts, Wearable devices, A fibre optic breath rate sensor and Transthoracic impedance.

Figure 1: Shows physical chest counts.

Fibre-optic breath rate sensor
This device is worn around the waist. In figure 2, we see that fibres are attached to a textile. This forms the device.
Figure 2: fibres attached to textile.
Although the normal range for an adult is 12-16, breaths per minute this device is usually set between 6-50 breaths per minute. This is because it has to take into account that the patient may not be at rest but active and other factors like these may cause an increase or decrease in respiratory rate.
Firstly, you apply the device around the chest or waist as seen in figure 3. It can be used for long term monitoring, as it is comfortable. It can be used in magnetic resonance imaging MRI scans because it is not affected by electromagnetic interference karek, 2014.
Figure 3: shows a patient wearing a fibre-optic breath rate sensor

Table showing the advantages and disadvantages of a fibre-optic breath rate sensor

Long-term monitoring as it is comfortable
There are high costs
No sensitivity to electromagnetic fields
Are weak and can break easily
They are small and have a low weight

This device can record different vital signs including respiratory rate. The bra consists of three components, heart rate monitor, respiratory monitor and pedometer. The device is worn around the torso of the body. The data is recorded on a box that is attached to the shirt of the patient but it can also connect to your phone via Bluetooth. It has a rechargeable battery that works as its power source Anon, 2017.

Table showing advantages and disadvantages of the OMBra

It is very comfortable It is very expensive
It is made of material that detects odour and removes it Not easy to maintain and wash.

Figure 4: showing the OMBra

These electrodes can be worn on any part of the body and they do not require any gel. This device is made up of electrocardiography ECG sensors, respiratory monitors and a thermometer. The two main advantages of this device are that they are very small and compact and do not need adhesive Anon, 2018.
Figure 5: showing sense pro dry electrodes

When using an electrocardiogram ECG to measure respiratory rate we look at different waveforms. ECG signals can measure respiratory rate in two different ways. The first one is simpler than the second is, it can measure the amount of ECG samples in R-R intervals. The second method detects the size of R wave in QRS signal. Both of these can be seen in figure 6. This second method is very complicated. These methods are used when we measure with the ECG signals. Kim, 2017
Figure 6: showing respiratory rate with ECG signal
We can also use ECG electrodes to measure respiratory rate. This form of recording is called transthoracic impedance. One of the disadvantages is that you need special purpose hardware but its biggest advantage is that it gives a continuous respiration related waveform.

Figure 7: showing ECG electrodes setup and waveform

There is a third method when using an ECG. This method is better for younger patients. It looks at the beat to beat differences in RR intervals Moody, 2016
Figure 8: showing the third method of an ECG

Many factors can affect your respiratory rate. These include your age, emotional status, exercise, internal temperature and oxygen and carbon dioxide levels.
We can see that there are many ways and devices that can used to measure the respiration rate. Each of the devices I have researched use many different methods to measure the respiration rate in different ways but they all have the same outcome, they give us respiration rate. Each device has advantages and disadvantages but each one is suited for a different situation and different patients.

Anon. 2017. OM-Bra. Available: Accessed 5 September 2018.

Anon. 2018. Sense-pro-dry-electrodes. Available: Accessed 5 September 2018.

Eldridge, L. 2018. What is a normal respiratory rate? Available: Accessed 4 September 2018.

Hopkins, J. 2018. What are vital signs? Available:,P00866 Accessed 4 September 2018.

Karek, M. 2014. An Optical Fibre-Based Sensor for Respiratory Monitoring. Available: Accessed 5 September 2018.

Moody, B. G. 2016. ECG-derived respiration. Available: Accessed 5 September 2018.

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