Post on 06-May-2015
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
Dept. of Instrumentation Tech, RVCE
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
Dept. of Instrumentation Tech, RVCE
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
Dept. of Instrumentation Tech, RVCE
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”
Dept. of Instrumentation Tech, RVCE
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.
Dept. of Instrumentation Tech, RVCE
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
Dept. of Instrumentation Tech, RVCE
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 curvevalues .
Dept. of Instrumentation Tech, RVCE
Dept. of Instrumentation Tech, RVCE
Dept. of Instrumentation Tech, RVCE
Dept. of Instrumentation Tech, RVCE
ANALOGY
The electronic nose system is analogues to the mammalian Olfaction system.
Dept. of Instrumentation Tech, RVCE
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.
Dept. of Instrumentation Tech, RVCE
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.
Dept. of Instrumentation Tech, RVCE
SENSORS EMPLOYED IN E-NOSE SYSTEM
PHYSICAL CHANGE TYPE OF SENSORS
conductivity Conductivity sensors
mass Piezoelectric sensors( SAW)
optical Optical sensor
Work function MOSFET
Dept. of Instrumentation Tech, RVCE
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
Changes in drain source current and
the gate voltage are also considered as response mechanism
Fig : MOSFET based sensor
Dept. of Instrumentation Tech, RVCE
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
Dept. of Instrumentation Tech, RVCE
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.
Dept. of Instrumentation Tech, RVCE
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
Dept. of Instrumentation Tech, RVCE
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.
Dept. of Instrumentation Tech, RVCE
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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