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How to Choose a Good Spirometer

This article is based on the articles Office Spirometers: The Good, The Bad, And The Ugly (P.L. Enright, M. Swanney, D. Burton and G. Liistro - The Buyers’ Guide To Respiratory Care Products) and Comment choisir un matériel spirométrique portatif? (How to choose a good portable spirometer? by A. Perdrix, F. Scarnato, A. Maître - Info Respiration).

There are many spirometers on the market. We try to give an overview of the important characteristics to look for while choosing a spirometer.

Quality of the results

Obviously the most important feature is the quality of the spirometer's test results.
Good spirometers were tested by an independent laboratory using a waveform generator.
A recent article, published in Chest, showed some important differences in the quality of the results from different spirometers in a field setting.

Curves

It is of the utmost importance that the spirometer (software) shows the flow-volume and volume-time curve after the test.
Good spirometers will also show the flow-volume loop in real-time during the test maneuver.

Quality Control

Most spirometers give a quality control after the test. A good spirometer will recognize signes of a sub maximal FVC.

User Friendliness

One can distinguish PC based and stand-alone spirometers. A choice between one or the other should depend on the user’s needs.
User friendliness of software or spirometer are important.

Calibration

Even in spirometers that do not require calibration (turbine, ultrasound) the possibility to check calibration and to adapt calibration - when necessary - should be present.

BTPS correction

Automatic correction to BTPS values is recommended. If not present, the possibility to introduce temperature and atmospheric pressure should exist.

Correction for Ethnicity

There are differences up to 13% in spirometry values between different ethnic groups. Clearly this should be taken into account when interpreting results.

Mouth Pieces

Many spirometers need special tailored mouthpieces that are often expensive. Other models use standardized mouthpieces that are freely available and often cheaper.

Prices of mouthpieces between spirometers vary between € 0,10 and € 3,00.

Cross Contamination

The possibility should be present to use an antibacterial filter for patients at risk. Some spirometers use disposable sensors.

Maintenance

Spirometer maintenance should be easy.

Print-out

The spirometer should be able to generate a print-out containing all the spirometry values, flow-volume loop and volume-time graph.

Reproducibility

A good spirometer calculates reproducibility of different tests.

Portability

A portable spirometer contributes to user friendliness and can be useful if spirometry tests are performed in different rooms or at different locations.