Spirometers

The ability to efficiently inhale and exhale oxygen is essential for life as well as good health. The most common way medical doctors will test the efficiency of a patients lungs is through a spirometry test.

Spirometry is what the test is referred to as while a spirometer is the device used during the test.

Spirometry is mainly used to diagnose Chronic Obstructive Pulmonary Disease (COPD), however it is also used to monitor the severity of other lung conditions as well as the lung’s response to medication. The spirometry test itself looks at how well the lungs are working as oxygen is inhaled and exhaled. Spirometry tests show four main patterns: A normal pattern, an obstructive pattern, a restrictive pattern, and a combined obstructive and restrictive pattern. Modern day Spirometers are precision instruments that use a differential pressure transducer for the measurements of respiration flow rates.

Although a multitude of different companies make spirometers they all work and measure essntially the same thing. All spirometers have a mouthpiece that the patient blows into and are connected to a device that will either elctronicly measure airflow or measure it through an analagous method. There are six main typs of spirometers. The Whole body plethysmograph, Pneumotachometer, Fully electronic spirometer, Incentive spirometer, Peak flow meter, Windmill-type spirometer, and the Tiltcompensated spirometer. The Whole Body Plethsymograph gives a more accurate measurement for the components of lung volumes as compared to other conventional spirometers. A person is enclosed in a small space when the measurement is taken.

The Pneumotachometer measures the flow rate of gases by detecting pressure differences across the fine mesh. One advantage of this spirometer is that the subject under investigation can breathe in fresh air during the experiment. Electronic spirometers have been developed that compute airflow rates in a channel without the need for fine meshes or moving parts. They operate by measuring the speed of the airflow with techniques such as ultrasonic transducers, or by measuring pressure difference in the channel. These Spirometers have greater accuracy by eliminating the momentum and resistance errors associated with moving parts such as windmills or flow valves for flow measurement.

They also allow improved hygiene between patients by allowing fully disposable air flow channels.

The Incentive spirometer is designed to improve the patients lung function while the peak flow spirometer only measures. Windmill-type spirometer is also known as Spiropet spirometer. It is used specially for measuring forced vital capacity without using water and has broad measurements ranging from 1000 ml to 7000 ml. Tilt-compensated type spirometer also known as the AME Spirometer EVOLVE. This new spirometer can be held horizontally while taking measurements but should the patient lean too far forward or backwards the spirometer's 3D-tilt sensing compensates and indicates the patient position.