I was planning on making a Breathalyzer for Detecting Disease by the using sensors for carbon monoxide, carbon dioxide and acetone but it seems it was a pretty broad idea and the difficulty is too high so I decided to pursue the Carbon Monoxide Monitoring idea and sending this data to a mobile app. The level of carbon monoxide in a person's breath will corresponding to the health status of the person. I was wondering anyone has ever done this before or it is possible to implement?
... using arduino sensors ...
There are no "Arduino" sensors. That's like saying using "Windows" sensors. Arduino is just a microprocessor. Have you researched sensors in general to see what is available?
i am sorry for quoting it that way. I was actually trying to say that i would use available arduino gas sensors for each (acetone, carbon monoxide and carbon dioxide).
possibly i will use the sensors here : Arduino Playground - HomePage
Research sensors some more. Those sensors are not suitable for breath analysis due to all the water in breath, they also need regular calibration because they drift. Finally they need to be on for 48 hours before they are stable and the heaters take a lot of current.
It sounds like an almost impossible task you have there.
darkatsuki12:
Hello. I am planning in creating a breathalyzer that can detect the acetone, carbon monoxide and carbon dioxide from the exhaled breathe using gas sensors(for acetone,carbon monoxide and carbon dioxide). I would like to inquire if it is possible to do this or not
I'd say: It depends on the sensors.
But most likely you want to detect just a few ppm of gas in the breathe, while the sensors provide a sensitivity of thousands of ppm or even percentages of gas.
For detecting just a few molecules, you possibly will need to use a gas chromatograph to get a signal.
So my answer is: It may work if your sensor is a "gas chromatograph", but if you are thinking of some "cheapo Arduino gas sensor": No chance.
darkatsuki12:
i am planning on tackling some lung diseases and diabetes that can be detected in breathe.
What's your budget? $50?
jurs:
I'd say: It depends on the sensors.But most likely you want to detect just a few ppm of gas in the breathe, while the sensors provide a sensitivity of thousands of ppm or even percentages of gas.
For detecting just a few molecules, you possibly will need to use a gas chromatograph to get a signal.
So my answer is: It may work if your sensor is a "gas chromatograph", but if you are thinking of some "cheapo Arduino gas sensor": No chance.
I see thanks for the information about gas chromatograph. I decided to just pursue the breathe carbon monoxide idea instead of pursuing the last idea.
if possible less than $40. I decided that the idea of detecting diseases through the three gases will be very difficult so i'll just pursue in detecting the exhaled carbon monoxide.
I plan to use this sensor: http://www.ddscientific.com/uploads/5/7/1/3/57136893/s_4_2ecoh_datasheet___.pdf
darkatsuki12:
if possible less than $40. I decided that the idea of detecting diseases through the three gases will be very difficult so i'll just pursue in detecting the exhaled carbon monoxide.
I plan to use this sensor: http://www.ddscientific.com/uploads/5/7/1/3/57136893/s_4_2ecoh_datasheet___.pdf
And where do you get a signal amplifier for the output amplification of the sensor?
This sensor will require a highly developed circuit of external components for a signal amplifier circuit until you get a signal that you can read with an Arduino.
Your sensor datasheet tells:
Output signal 175 ± 50 nA / ppm
Measurement Range 0 - 200 ppm
That is nano or micro amperes as output!
And the signal is heavily temperature dependent, see diagram in the datasheet!
But the only ranges of Arduino for analog input is the ADC with
- default range 0...5 volts
- internal range 0...1.1 volts (Atmega328)
- external range (you provide the reference voltage)
So where do you get the required signal amplifier circuit from?
See application note (for a different sensor and different microcontroller I found using Google): http://www.st.com/web/en/resource/technical/document/application_note/DM00093722.pdf
Figure 10 in that document shows a signal amplifier circuit needed for carbon monoxide sensing.
The amplifer needed for Arduino and 2ECOH sensor is similar.
The picture "Figure 13: Gas-sensing evaluation board" will show you a signal amplifier circuit with sensor on a printed circuit board, ready to connect it to a microcontroller board.