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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ElectronicManiac
Tue Mar 31 2015, 03:33 PM
anyone?
ElectronicManiac
Tue Mar 31 2015, 03:33 PM
Please Reply me on Scrolling Dot Matrix LED Display using 8051
Tue Mar 31 2015, 10:32 AM
Akshayy
Can you please provide the proteus file
ajay_bhargav
Tue Mar 31 2015, 04:14 AM
@Peter james, we have many projects related to this, Please refer download section and tutorials or post in forum for specific questions.
Mon Mar 30 2015, 04:51 PM
Peter james
can any one provide me an assembly language program to interface with 16x2 LCD, 4X4 Keypad and a GSM Module to recieve message and display it.
ajay_bhargav
Mon Mar 23 2015, 04:22 AM
You can only simulate simple 8051. RD2 support is not there in proteus. However there are similar atmel varient which can be used instead.
Sun Mar 22 2015, 07:24 PM
Aryan Nath
How can i Simulate microcontroller project in Proteus that uses P89V51RD2
Thu Mar 19 2015, 02:45 PM
Peter Mann
I have tried to register on the site, but it keeps saying I've entered two different email adresses - but I haven't!
ajay_bhargav
Sun Mar 15 2015, 08:25 PM
I did not get new message indication.. strange..
ExperimenterUK
Sun Mar 15 2015, 08:18 PM
slight delay, my connection failed

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Tue Mar 31 2015, 04:47 PM
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diana1234 Avatar
Posted By diana1234
Tue Mar 31 2015, 11:17 AM
Thank you sir for the reply,As you give the LED ex...
mayank058 Avatar
Posted By mayank058
Tue Mar 31 2015, 06:44 AM
Dear Iamalien, Thank you ...
mayank058 Avatar
Posted By mayank058
Tue Mar 31 2015, 06:33 AM
Thanks to all of u for showing your interest in my...
iamalien Avatar
Posted By iamalien
Tue Mar 31 2015, 04:43 AM
here you go a 227 variable array in the ram and st...
ajay_bhargav Avatar
Posted By ajay_bhargav
Tue Mar 31 2015, 04:33 AM
Can you post Keil compiler output?
iamalien Avatar
Posted By iamalien
Tue Mar 31 2015, 04:31 AM
i have already compiled the program in keil thats ...
ajay_bhargav Avatar
Posted By ajay_bhargav
Tue Mar 31 2015, 04:29 AM
Its in nature of resistor to reduce the current wh...
ajay_bhargav Avatar
Posted By ajay_bhargav
Tue Mar 31 2015, 04:10 AM
256 bytes ram for 200 char display... I think you ...
diana1234 Avatar
Posted By diana1234
Mon Mar 30 2015, 08:12 AM
Dear sir,How a resistor can be used as a current l...
ExperimenterUK Avatar
Posted By ExperimenterUK
Mon Mar 30 2015, 05:13 AM
The processor on the MCB2300 has a built in DAC.Cr...