The lungs are vital organs in the body and they are responsible for providing oxygen to be circulated and used in various biochemical processes in our body. Spirometry is a common test to measure the performance of the lungs by measuring the volume of air inhaled and exhaled by the individual and then depicting the data in the pneumotachographs namely, volume-time graph and flow volume loop. These are helpful in study of the diseases like asthma, pulmonary fibrosis, COPD and cystic fibrosis.
The earlier methods were mechanical systems. They failed to provide an exact interpretation of the problem due to the presence of inertial mechanical parts and loading effects of the systems. Electronic spirometers are much ahead of their earlier counterparts in these fields. This article discusses spirometer – types and what it is used for.
Pulmonary function tests
The pulmonary function tests are done to record the performance of the lungs especially by measuring the amount of air inhaled and exhaled. The results of the test are very useful in diagnosing abnormalities like asthma and bronchitis and causes for shortness of breath. They are also done to get preliminary knowledge of the condition of the lungs before doing any surgery. They also determine the effects of drug’s efficacy.
This type of testing helps predict a set course of diagnosis in case of diseases like asthma, bronchitis and emphysema and such other lung diseases. It is a helpful tool in determining the aftermath of such diagnosis as well.
Types of spirometers
- Whole body plethysmograph: Better than other conventional approaches. Person is enclosed in a small area where measurements are taken.
- Pneumotachometer: Flow rate of gases is calculated by determining pressure differences across a fine mesh.
- Fully electronic spirometer: It’s accurate and uses ultrasonic transducers and ensure good hygiene by providing disposable air flow channels.
- Incentive spirometer: This is specially designed for improving functioning of lungs.
- Peak flow meter: Used for measuring the exhaling ability of lungs.
- Windmill-type spirometer: Portable, lighter and more handy with rotating benefits while taking measurements.
- Tilt-compensated spirometer: Also known as AME spirometer EVOLVE. The patient has to lean forward and backward. Readings can be recorded horizontally. The tilt sensing capability compensates for the patients position.
Spirometry is a procedure whose results are extremely dependent on the cooperation of the patient. Hence it is not advisable for patients of young age and old age, who cannot follow the instructions properly. In addition, the detection of mild and acute asthmatics is not predictable in the tests as they show normal results.
However over the years, with the advent of electronics into the field of biomedical instrumentation, spirometry has undergone major changes to make it comfortable to individuals undergoing tests and to gain reliability in its results in terms of accuracy.