Of all the body responses one could monitor, heart rate is one of the most important because it fluctuates greatly depending on our state of mind and physical condition. Heart rate during physical activity gives us a direct indication of our fitness level, and heart rate changes throughout the night can be clear indicators of when a dream cycle has begun. A heart rate monitor is also a very easy device to use for extended periods because it can
be placed on the body in such a way that is not uncomfortable or in the way of any normal activity.

The heart rate monitor project presented here uses a sensitive light-detecting resistor to detect small changes in the light beaming through your finger as your blood pumps through the tiny arteries in the finger. This device is not the same as the heart rate monitors typically used in hospitals because those use skin probes that detect changes in electrical activity as the heart beats. This heart rate monitor actually “sees” your pulse through the body, so it can be used on a finger, toe, or even your earlobe.

The heart rate monitor is a combination of analog and digital circuitry, as shown below.



The LM324 quad op amp (IC1) forms a sensitive amplifier and a low-pass filter that will “lock” onto tiny variations in voltage that fall within the typical heart rate frequencies. The varying voltage comes from the light-dependent resistor (LDR), which changes a very small amount each time blood pumps through the tiny arteries in between the visible red LED and the LDR surface.




Complete Design



Insert Your Fingure Here







if you feel any doubt or need further details feel free to use Forum.
Source: Evil Genius MPP Issue 2010
[Submitted by coolmirza143]
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ExperimenterUK
Fri Feb 12 2016, 04:39 AM
@ Ankush SS .. source code for what?
plinniocom2n
Fri Feb 12 2016, 12:17 AM
thank you
Tue Feb 09 2016, 05:17 PM
Ankush SS
Can i get the source code of this project? Please n thnk u for ur kindness
Fri Feb 05 2016, 08:33 AM
SANJYOT JADHAV
sir did we have to use Gsm modem for testing the circuit on proteus
Tue Feb 02 2016, 11:17 AM
upendra kumar
i want information about 3-phase motor control using gsm technology
Sat Jan 16 2016, 05:33 PM
Kenneth Etuk
Hi everyone, I need help with a project involving MCU,rttc, and DC motor. I will pay for it. please reply to my mail [email protected] if you are interested. thanks
ExperimenterUK
Sat Jan 16 2016, 02:08 AM
@Kabona Log in and create a thread. Tell us what you want to do
Tue Jan 12 2016, 08:24 PM
Kabona
how can I make my pc be input and output device for the microcontroller
Sat Jan 09 2016, 07:04 AM
Ravz
Thank u..... one more doubt Will ultrasonic sensor HC-SR04 works with aurdino board in operating system linux
Tommy.Kofisterix
Fri Jan 08 2016, 08:50 PM
I know it detects also the mud on rear bumper, this means other obstacles will

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plinniocom2n
Fri Feb 12 2016, 12:12 AM
designAAA
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Sat Jan 16 2016, 05:54 AM
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ExperimenterUK Avatar
Posted By ExperimenterUK
Fri Feb 12 2016, 04:45 AM
How do I get the link to the file? plinniocom2nGoo...
plinniocom2n Avatar
Posted By plinniocom2n
Fri Feb 12 2016, 12:18 AM
How do I get the link to the file? Newbie here.
sankalp_s Avatar
Posted By sankalp_s
Thu Feb 11 2016, 06:28 PM
Hello phil sir finaly i'm dumping my code, now i'm...
ExperimenterUK Avatar
Posted By ExperimenterUK
Thu Feb 04 2016, 04:10 AM
Sir I didn't understand that. Could you explain ab...
sankalp_s Avatar
Posted By sankalp_s
Tue Feb 02 2016, 07:26 PM
but good use of sub routines will save a lot of ...
ExperimenterUK Avatar
Posted By ExperimenterUK
Tue Feb 02 2016, 12:25 AM
after removing ALLON instruction it's working fine...
ExperimenterUK Avatar
Posted By ExperimenterUK
Tue Feb 02 2016, 12:14 AM
Which micro controller are you using ?.Does it hav...
sankalp_s Avatar
Posted By sankalp_s
Sat Jan 30 2016, 07:40 PM
You need to explain exactly what you want the code...
ExperimenterUK Avatar
Posted By ExperimenterUK
Sat Jan 30 2016, 06:57 PM
>sir can you code this in any other method?You nee...
sankalp_s Avatar
Posted By sankalp_s
Sat Jan 30 2016, 06:47 PM
CALL ALLONCLR L1CLR L2CLR L3CLR L4CALL DELAY ;del...