Discussion in "General help Guidance and Discussion" started by    xmen    Feb 16, 2008.
Sat Feb 16 2008, 09:19 PM
#1
hi.........i need sensor to detect our heart beat .... anything available please guide me.......


[ Edited Wed Feb 27 2008, 06:21 AM ]
Mon Feb 25 2008, 08:14 PM
#2
use super bright led and LDR
Tue Feb 26 2008, 09:01 AM
#3
hi TPS, can you explain how LED and LDR can help to detect heart beat?
Sun Mar 02 2008, 06:10 PM
#4


hi TPS, can you explain how LED and LDR can help to detect heart beat?

Ajay


Mon Mar 03 2008, 07:46 PM
#6
curtsy binu


[ Edited Mon Mar 03 2008, 07:47 PM ]
Tue Mar 04 2008, 05:46 PM
#7
thank you TPS
and... i hope binu has no problem with sharing his circuits
Tue Mar 04 2008, 07:19 PM
#8
YES I hope so
Tue Mar 04 2008, 07:51 PM
#9
just one thing now.. how putting this sensor on finger can detect heart beat?
what is connection of heart beat with IR sensor? :-s
Tue Mar 04 2008, 09:19 PM
#10


Heart beat is sensed by using a high intensity type LED and LDR. The finger is placed between the LED and LDR. As Sensor a photo diode or a photo transistor can be used. The skin may be illuminated with visible (red) using transmitted or reflected light for detection. The very small changes in reflectivity or in transmittance caused by the varying blood content of human tissue are almost invisible. Various noise sources may produce disturbance signals with amplitudes equal or even higher than the amplitude of the pulse signal. Valid pulse measurement therefore requires extensive preprocessing of the raw signal.
The new signal processing approach presented here combines analog and digital signal processing in a way that both parts can be kept simple but in combination are very effective in suppressing disturbance signals. The setup described here uses a red LED for transmitted light illumination and a LDR as detector. With only slight changes in the preamplifier circuit the same hardware and software could be used with other illumination and detection concepts. The detectors photo current (AC Part) is converted to voltage and amplified by an operational amplifier (LM358). Output is given to another non-inverting input of the same LM358; here the second amplification is done. The value is preset in the inverting input, the amplified value is compared with preset value if any abnormal condition occurs it will generate an interrupt to the controller AT89C2051.

binu

Get Social

Information

Powered by e107 Forum System

Conversation

ExperimenterUK
Sun Jan 25 2015, 08:10 PM
This box is for chat. Post problems in a suitable forum
ExperimenterUK
Sun Jan 25 2015, 08:04 PM
@gaurav.k Use the purple "Post reply" button. Green buttons often present a fresh edit box.
ExperimenterUK
Sun Jan 25 2015, 07:33 PM
@avianash..we have no entry for avianash.. Are you sure that is your login name ?
Fri Jan 23 2015, 04:29 AM
lolokijuh
DJ Bakal tulungan mo ako s IC Tester
Fri Jan 23 2015, 04:29 AM
lolokijuh
sir help about IC Tester
Thu Jan 22 2015, 01:59 PM
apparao majji
could you please help in programming
Thu Jan 22 2015, 10:13 AM
avianash
hi my account is inactive plz help me
gaurav.k
Thu Jan 22 2015, 07:04 AM
not able top post any reply from my login... after pressing "post Reply "it takes me to a blank page
Thu Jan 22 2015, 04:06 AM
frankie
friend, that modification should be done in the program so that led up and down oscillation is one blink, thanks
Wed Jan 21 2015, 05:06 PM
Gargiarya
to get a clear view of seven segment with 8051 visit http://www.mechaterrain.com/seven-segment-fixed-display-using-8051

Downloads

Comments

nawfel
Sat Jan 17 2015, 07:27 AM
Rohi123
Sat Jan 10 2015, 11:00 AM
safakarici
Fri Jan 09 2015, 08:55 PM
Nikita_Pinjare
Thu Jan 08 2015, 03:10 PM
mayank058
Wed Jan 07 2015, 05:43 AM
Overeating
Tue Jan 06 2015, 05:56 AM
trancebreaker11
Sun Jan 04 2015, 07:42 AM
akash474001
Thu Jan 01 2015, 05:49 AM

Online

Guests: 47, Members: 0 ...

most ever online: 182184
(Members: , Guests: 182184) on 06 Aug 2010: 05:37 AM

Members: 37573
Newest member: nawfel
Forum Activity
ExperimenterUK Avatar
Posted By ExperimenterUK
Sun Jan 25 2015, 08:19 PM
According to this page the output is fairly linear...
mayank058 Avatar
Posted By mayank058
Thu Jan 22 2015, 12:16 PM
dear sir, Now i want to generate a si...
mayank058 Avatar
Posted By mayank058
Tue Jan 20 2015, 06:40 AM
dear sir, Now its working properly. Th...
ajay_bhargav Avatar
Posted By ajay_bhargav
Tue Jan 20 2015, 04:36 AM
ajay_bhargav Avatar
Posted By ajay_bhargav
Tue Jan 20 2015, 04:35 AM
I found another issue with your code:calling PWMIn...
mayank058 Avatar
Posted By mayank058
Mon Jan 19 2015, 05:47 AM
dear sir, Please do it for me..
PsySc0rpi0n Avatar
Posted By PsySc0rpi0n
Sun Jan 18 2015, 08:23 PM
But it's a way to debug to consider to the future ...
ajay_bhargav Avatar
Posted By ajay_bhargav
Sun Jan 18 2015, 06:04 AM
I remember i created small library for lpc23xx ser...
ajay_bhargav Avatar
Posted By ajay_bhargav
Sun Jan 18 2015, 06:00 AM
It's obviously a personal choice. Digging into map...
ajay_bhargav Avatar
Posted By ajay_bhargav
Sun Jan 18 2015, 05:58 AM
@karan123 I suggest you to create a new thread for...