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DETECTION OF LUNG CANCER IN PRIMITIVE
STAGE BY ANALYSIS OF VOLATILE ORGANIC
COMPOUNDS IN EXHALED AIR COMPOUNDS

By,
Ayush
Faisal Ameen
Siddharth DC
Santosh Srivatsa

Dept. of Instrumentation Tech, RVCE

INTRODUCTION
 Types of lung cancers


Small cell lung cancer:
 12 out of 100 patients are suffering from this type of cancer,
mainly caused due to smoking.

 Cured by chemotherapy rather than surgery.

Non-small cell lung cancer:
 Most common type of cancer which infiltrates regional lymph nodes and
adjacent organs.

 Depending on tumor size ,lymph node involvement and presence & absence
of distant metastasis this type of cancer is categorized into stageI, stageII,
stageIII & stageIV


LUNG CANCER DETECTION IN PRIMITIVE STAGE :METHODS

 PWS(partial wave spectroscopic microscopy)
-based on alteration in Buccal epithelium.

 Chest CT and PET scan

 Analysis of VOCs(volatile organic compounds) in exhaled
air using E-Nose


ANALYSIS OF VOCS IN EXHALED AIR USING
E-NOSE

Concept:

“The exhaled breath contains VOCs .
Analysis of Exhaled breath can be analyzed to
detect lung cancer in primitive stages . This
analysis results in the detection of “biomarkers”, 1-
butanol and 3-hydroxy-2-butanone in the exhaled
air which indicates the probability of lung cancer”


 The “electronic nose” is an electronic detection system
consisting of an array of coated sensors, which can
detect VOCs. And the change in chemical reactivity or
electrical properties of the Enose can be analyzed to
evaluate certain important parameters:

 Breath samples are taken from lung cancer patients,
healthy nonsmokers, Ex-smokers, and patients with
respiratory condition.

Implementation :
 Oral exhaled breath was collected in Tedlar bags.

 The gas from each bag was analyzed by the Enose, resulting
in a total of four graphic displays per subject.

 The E-Nose is an electronic detection system with an array of
6-channel coated chip sensors, each consisting of tin oxide
electrodes with individualized highly-reactive rare earth coatings.

 These element coatings undergo oxidation which is detected by a
chip-based microelectronic device as a change in resistance, which
results in change in voltage and is recorded simultaneously for all
channels.


 An additional two channels provided measurements of
temperature and humidity.

 An electronic memory is generated allowing the
identification of similar patterns between samples
rather than the identification of specific compounds.

 The output from each channel is graphically displayed
the following parameters are analyzed :
 The peak height of the curve
 Rate to peak height,
 Rate of recovery, and
 Area under the curve


 Results:
Rate to Peak Height:
 Patients with lung cancer had significantly lower rates to
peak height for when compared with other subjects.

Peak Height:
 Lung cancer patients had significantly lower peak height values
when compared to other subjects.

Rate of Recovery:
 Lung cancer patients having significantly lower rate of recovery
values when compared with other subjects.

Area Under Curve:
No significant differences were seen for lung cancer patients
And other subjects when comparing area under the curve
values .


ANALOGY

 The electronic nose system is analogues to the
mammalian Olfaction system.


E-NOSE RESPONSE TO ODORANTS
 Regarded as first order response

 Reference gas is flushed through the sensor to
obtain the base line.

 Sensor is exposed to the odorant which causes
change in the output signal, until steady state is
reached.

 Finally odorant is flushed out of the sensor using
the reference gas resulting in the sensor to return
back to its base line.


 Time during which sensor is exposed to the odorant
is referred to as Response Time.

 while the time sensor takes to return to the base line
resistance is called the Recovery Time.

SENSORS EMPLOYED IN E-NOSE SYSTEM

PHYSICAL CHANGE TYPE OF SENSORS

conductivity Conductivity sensors

mass Piezoelectric sensors( SAW)

optical Optical sensor

Work function MOSFET


MOSFET SENSOR:
 Works on the principal that the
threshold voltage of the sensor
changes on interaction with the gate
material [porous gas sensitive] with
certain gases such as hydrogen.

 Threshold voltage changes due to
change in work function of the
metal and oxide layer

 Change in threshold voltage s
proportional to concentration of the
analyte Fig : MOSFET based sensor

 Changes in drain source current and
the gate voltage are also considered
as response mechanism


Optical Sensor:
 optical fiber sensor arrays have there size or tips coated with a
florescent dye encapsulated in a polymer matrix as shown in fig.

 Polarity alterations in the florescent dye, on interaction with the gas
changes its optical properties such as intensity, spectrum and
wavelength shift.

 These optical changes are used as response mechanism for odor
detection


Surface acoustic wave sensor[SAW]:
 It is composed of piezoelectric substrate with an input(transmitting)
and output (receiving ) interdigital transducer deposited on top of
the surface

 It is a class of microelectromechanical systems (MEMS) which
rely on the modulation of surface acoustic waves to sense a
physical phenomenon.


Conducting Sensors:
 It works on the principal
that interaction with gas
leads to change in
resistance.

 Sensing material is
deposited over two parallel
electrodes through which
relative resistance measure


CONCLUSION

 From the detailed analysis of the sensors its been
found that lung cancer can be detected in primitive
stage by following our non invasive and inexpensive
technique.


REFERENCES
 IEEE SENSORS JOURNAL, VOL. 10, NO. 9, SEPTEMBER 2010
 Sensors 2009
 Wikipedia.com
 Thebestoncologist.com
 http://www.uta.edu
 www.mdpi.com/1424-8220/9/7/5099/pdf
 http://www.emeraldinsight.com/journals
 www.irma-international.org

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