Friday, May 9, 2014

Understanding Various Types Of Spirometers

By Tracie Knight


Spirometry is a medical procedure used to measure lung functions, specifically the volume and speed of the air one breathes in and out. It is one of pulmonary function tests and it is also referred to as measuring of breath. Spirometry is performed using pieces of equipment called spirometers. There are many version and models of these apparatus in the market, giving a buyer a wide range of options to choose from.

The work of this equipment is to determine abnormal ventilation patterns and how air moves in and out of the lungs. This device is normally able to detect two kinds of abnormal ventilation patterns. The first abnormal pattern is restrictive while the second one is obstructive. Different device models use different measurement methods to achieve their functions. Some of most common methods include use of water gauge, ultrasonic, and pressure transducers.

These devices keep improving with the ever improving technology. Currently several models are in application in various sectors around the world. Among the main models are whole body plethymograph, fully electronic, tilt compensated, pneumotachometer, windmill-type, incentive, and peak flow type model. The most accurate model of all the models is whole body plethymograph, which gives high accuracy in values recorded. The high accuracy is partly because patients are enclosed in rooms during the exercise.

Pneumotachometers gauge rate or flow of air by use of fine meshes. Pressure of breathed air is sensed and measured as the air flows over the fine meshes. This allows for its rate of flow to be measured too. As the procedure continues, the patients can inhale fresh air. This does not exist in other models.

Previous models have been improved to come up with the fully electronic version, which does not use moving parts or fine meshes. In fully improved models, techniques like ultrasonic transudcers and pressure difference are used to gauge rate of air flow. Accuracy is greatly improved because no friction due to resistance is experienced since no moving parts are present. Disposable air flow channels in the products improve hygiene.

The most commonly used type is the incentive model. These models improve gaseous exchange in the lung of patient when used for a long time. In hospitals they are placed on benches or tables next to beds. Doctors instruct patients to breathe through them for a given number of times daily. Any improvements the patient makes in their breathing habits can be observed on the calibrations on the apparatus.

Windmill-type model is able to gauge forced vital capacity without involving water. When compared to water-tank types, it has lower weight and higher portability. Measurements taken are wide and lie between 7000ml and 1000ml. When recording measurements, this apparatus must be held in horizontal position due to the presence of revolving discs. Tilt-compensated types contain 3D sensing mechanics that permit forward or backward positions during use.

The cooperation the patient gives the doctor highly determines how successful the testing process can be. Normally values obtained from a single test are not used because they contain errors. The procedure is therefore repeated at least three times to obtain final values. Little kids who cannot understand instructions cannot also be tested because of the same reason.




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