Instrument Specification Flashcards
Section 10
What requirements should a spirometer have?
Capable of measuring volumes of at least 8 litres (BTPS), independent of flow rate for flows of 0-14 litres per second and capable of accumulating volume for at least 15 seconds
Flow accuracy
Flow should be accurate within plus or minus 3% of the reading or plus or minus 50 ml, whichever is greater
How many maneuvers can you perform within 10 minutes?
Eight maximum
As displays for flow volume and volume time control provide quality control they must :
Meet minimum size and resolution requirements
Have the ability to overlay more than one curve to evaluate repeatability.
Flow volume tracking evaluates what?
Clients maximal inhalation effort
Volume time tracings evaluate?
The end portion of the maneuver
Start of test must be determined by…
The back extrapolation method
Start of test should be
Crisp.. no coughs, second inspirations, or other irregularities.
FEF25-75% must be measured with an accuracy of at least ..
+/- 5% or +/- 0.200Ls-1 whichever is greater over a range of up to 7 Ls-1
FEF25-75% is highly dependent on what valid measurement
FVC and a good level of expiratory effort
Spirometers should provide a written tracing of what two volumes for a whole forced expiration
Volume vs time and volume vs flow vs time
The spirometer must be capable of displaying the entire FVC maneuver at a constant speed from
Maximum inspiration to at least 15 seconds after the start of the maneuver
The paper speed should be…
20 mm per second or faster
Volume sensitivity should be…
10 mm per liter of volume
Flow sensitivity should be
4 mm per liter per second of flow
What does calibration establish?
The relationship between sensor-determined values of flow or volume and the actual flow or volume.
Calibration should be done daily before conducting testing to demonstrate what?
That the spirometer is functioning accurately before use.
When calibrating what is the acceptable spirometer recorded volume
+/- 3.5% or 2.90 to 3.0 L at three different speeds
What are the approximate 3 different speeds for calibrations?
0.5 seconds, 3 seconds, and 6 seconds
The air in the calibration syringe should be at the same ___ and ____ as the air inside the spirometer
Temperature and relative humidity
What are two types of spirometer?
Volume and flow
Volume spirometers record what?
Amount of air exhaled or time within a certain time
Flow spirometer measure what?
how fast the air moves in or out as the volume of air inhaled or exhaled increases
Instrument volume standard
8 liters in btps
Flow rate standard
0 to 14 liters per second
Fvc test time standard
At least 15 seconds
Fvc volume accuracy standard
Plus or minus 50 ml or within 3% of the reading whichever is greater
Temperature and pressure Standard
Conversion to btps either by the instrument or the user
Fev1 volume accuracy standard
8 liter btps with accuracy of plus or minus 50 ml or within 3% of the reading whichever is greater
Start point of the test standard
0 time Point determined by back extrapolation method this requires activation of the recording chart prior to fvc maneuver
Inertia and resistance Standard
Less than 1.5 CM H2O per liter per second at 14 liters per second
Fef 25 to 75% volume standard
Accuracy of plus or minus 5 percent of the reading or plus or minus 150 ml per second whichever is greatest
Tracing requirements standards
Flow versus volume or volume versus time
Paper speed of 20 mm per second
Volume sensitivity of at least 10 millimeter of paper per liter of volume
Flow sensitivity of at least 4 millimeter per liter per second
