Midterm 2 Flashcards
_______ requires measurement of gas volume or flow, and various instruments and measurement principles are used to make these measurements.
Pulmonary function testing
There are two general types of measuring instruments: _____ and ____
instruments that measure gas volume and instruments that measure gas flow.
Both types of instruments simultaneously measure time, and both compute various volumes and flow rates used in pulmonary function testing.
instruments that measure gas volume and instruments that measure gas flow.
The _____ is sometimes used as a generic term for all volume-measuring and flow-measuring devices.
spirometer
_______ are specifically called spirometers and include water-sealed, bellows, and dry rolling seal types.
Volume-measuring devices
These devices expand as they collect gas volumes.
Volume-measuring devices
The magnitude of the expansion is the _____ measured, and the speed of expansion represents the ____
volume and flow rate
In the absence of leaks and with low-momentum forces, _______ can be extremely accurate for measuring volumes, and with low inertia and friction forces, _____ can be extremely accurate when computing flow rates.
volume-measuring devices
_______ are commonly called pneumotachometers
Flow-measuring devices
Flow-measuring devices are commonly called pneumotach- ometers, although some practitioners reserve this term for only the device originally designed by _____.
Fleisch
These devices measure flow using a variety of unique principles.
Flow-measuring devices
The _____ measures the change in pressure as gas flows through it.
Fleisch-type pneumotachometer
Known as ___ or ____ , another type of flow-measuring device measures the temperature change created by gas flowing through it.
thermistors or mass flowmeters
There are also ______ , which use rotation of a fan or blades similar to a windmill.
turbinometers
Every measuring instrument has ______
capacity, accuracy, error, resolution, precision, linearity, and output.
The ideal instrument would have ______ to measure every pulmonary parameter, and it would have ____ and ____ over its entire measurement range.
unlimited capacity / perfect accuracy and precision
However, in real practice, there are no ______
ideal instruments
The _____ of an instrument refers to the range or limits of how much it can measure.
capacity
_____ is the combination of two or more lung volumes
capacity
Most instruments are designed with _____ to measure volumes and flow rates of all adults.
capacities
The ______ of a measuring instrument is how well it measures a known reference value.
accuracy
For volume measurements, standard reference values are provided by a graduated ____
3.0-L calibration syringe.
No measuring instrument is perfect, and there usually is an ____ difference between reference values and measured values. This difference is called the ____.
arithmetic / error
___ and ____ are opposing terms;
Accuracy and error
the greater the ____ , the smaller is the ____.
accuracy / error
Accuracy and error are commonly expressed as ____, with their sum always equaling ____
percentages / 100%.
To determine ____ and _____ , an object of known measurement (e.g., 3-L cylinder) is tested multiple times and the absolute value of the deviation from the known measurement (error) calculated. The average value of the error over multiple tests is then computed.
percent accuracy and percent error
______ is the smallest detectable measurement; instruments with high _____ can measure the smallest volumes, flows, and times.
Resolution
_____ is synonymous with reliability (repeatability) of measurements and the opposite of variability.
Precision
When multiple values are measured for a given test, the standard deviation of these values indicates the extent to which these values vary from the mean and is therefore an indication of the ____ of an instrument.
precision
A small standard deviation indicates low variability and ______.
high precision
_____ refers to the accuracy of the instrument over its entire range of measurement, or its capacity.
Linearity
Some devices may accurately measure large volumes or high flow rates but may be less accurate when measuring small volumes or low flow rates.
Linearity
To determine _____ , accuracy and precision are calculated at different points over the range (capacity) of the device.
linearity
____ includes the specific measurements made or computed by the instrument.
Output
Most volume-measuring and flow-measuring devices measure the ____ and _____ . Others calculate various forced expiratory flow (FEF) rates, and some measure tidal volume(VT) and minute ventilation (V̇E).
FVC and forced expiratory volume in 1 second (FEV1)