Pulmonary function tests (PFTs) measure how well the lungs work. There are several types of PFTs: spirometry measures airflow; lung volume measures how much air is in the lungs; and diffusion testing measures how well oxygen moves from the lungs into the bloodstream. PFTs can diagnose lung diseases like asthma, identify causes of shortness of breath, and assess treatment effectiveness. Abnormal PFT results usually mean the subject may have a lung disease if values are less than 80% of predicted normal levels based on factors like age, height and sex. PFT devices precisely measure things like airflow, gas volumes and pressures to evaluate lung function.

1. Welcome you all
By : LOKENDRA YADAV

2. What is pulmonary function
test’s?(PFTs)

3. • Pulmonary function tests are a group
of test that measure how well the
lungs take in and release air and how
well they move oxygen into the
blood.(it is a non invasive)

4. How the test is
performed?

5. SPIROMETRY…
In a spirometry test, you breathe into a
mouthpiece that is connected to an
instrument called a spirometer. The
spirometer records the amount and the
rate of air that you breathe in and out
over a period of time.

6. Lung volume measurement can be done in two
ways:
•The most accurate way is to sit in a sealed, clear
box that looks like a telephone booth (body
plethysmograph) while breathing in and out into a
mouthpiece. Changes in pressure inside the box
help determine the lung volume.

7. Body plethysmograph

9. •Lung volume can also be measured when you
breathe nitrogen or helium gas through a tube for a
certain period of time. The concentration of the
gas in a chamber attached to the tube is measured
to estimate the lung volume.
•To measure diffusion capacity, you breathe a
harmless gas for a very short time, often one
breath. The concentration of the gas in the air
you breathe out then is measured. The difference
in the amount of gas inhaled and exhaled can
help estimate how quickly gas can travel from the
lungs into the blood.

10. Why the test is performed?

11. Pulmonary function tests are done to:
•Diagnose certain types of lung disease (especially
asthma, bronchitis, and emphysema)
•Find the cause of shortness of breath
•Measure whether exposure to contaminants at work
affects lung function
It also can be done to:
•Assess the effect of medication
•Measure progress in disease treatment

12. Spirometry measures airflow. By measuring how much air you exhale,
and how quickly, spirometry can evaluate a broad range of lung diseases.
Lung volume measures the amount of air in the lungs without
forcibly blowing out. Some lung diseases (such as emphysema and
chronic bronchitis) can make the lungs contain too much air. Other lung
diseases (such as fibrosis of the lungs and asbestosis) make the lungs
scarred and smaller so that they contain too little air.
Testing the diffusion capacity (also called the DLCO) allows the doctor
to estimate how well the lungs move oxygen from the air into the
bloodstream.

13. Normal value of PFTs is depend upon subject height ,age
and sex normal results
Are expressed as a percentage .A value is usually
considered abnormal if it less than 80% of predicted value.
Abnormal value usually mean that subject may have some
chest or lung disease

14. PULMONARY FUNCTION ANALYZERS(PFA)
Three basic type of measurement made in pulmonary
clinic
Ventilation: simple inhalation and exhalation.
Distribution: This is measurement quantify the degree of
lung obstruction and also determine the residual
volume(second method by inhaling Nitrogen)
Diffusion: This measurement is performed to determine the
rate at at which gas is exchanged with the blood stream.

17. PFA provide a complete
evaluation of lung function
or the respiratory process

20. NITROGEN
ANALYZER
?

21. It allows rapid analysis of
nitrogen concentration
(volume%) in respiratory air.

23. NITROGEN LINEARIZER: In case of
nitrogen washout during human physiological
investigation require stable linear input device. for
this purpose it was necessary to obtain a precision
of 0.02% nitrogen (0.02% of the avg nitrogen
usually encountered during a breath near the end
of the wash out)

24. By using low drift op-amp in nitrogen analyzer

25. AUTOGAIN
CIRCUIT
?

26. AUTO GAIN CIRCUIT is nothing but
it is a automatic gain control(AGC).
The avg o/p signal level is fed back
to adjust the gain to an
appropriate level of range of input
signal level

27. PNEUMOTACH
FLOW
TRANSDUCER
?

28. A Device that measure a the flow of
gases in form of pressure gradient.
And a pressure gradient developed by
PHEUMOTACH METER is directly related
to flow.

30. PRESSURE
TRANSDUCER
?

31. LINEAR AMP
?

32. LINEAR AMP is stand
for linear amplifier
very familiar term.

33. A linear amp is an electronic
circuit whose o/p is
proportional to its i/p but
capable of delivering more
power into a load if it
required

34. BTPS
?

35. B : BODY
T : TEMPERATURE
P : PRESSURE
S : SATURATION

36. BTPS : ABBREVATION is used for body
temperature ambient pressure saturated
water vapors condition of a volume of gas
for humans normal respiratory tract
temperature is measured at 37 degree
Celsius ,ambient pressure and the partial
pressure of water vapors at 37 degree Celsius
at 47 mm Hg

37. What is BTPS compensation?

38. A/D
CONVERTOR
?

42. PRESENT TRANSDUCER USED IN SPIROMETER……
TURBINE TRANDUCERS
actually a
rotating vane,
this spins, the
revolutions are
counted as
they break a
light beam
TRANDUCERS

43. MILLER,S QUADRANT…….
RESTRICTIVE NORMAL
120
F
E INS √
100
V
60
COMBINED OBSTRUCTIV
F 40 EXP
V
C
BOTH
% 20
0
20 40 80 100
120
FVC/FVCref %
TRANDUCERS

51. Thank You