8051 Microcontroller Projects AVR PIC Projects Tutorials Ebooks Libraries codes : Forum / topic http://www.8051projects.net/ Learn to make simple microcontroller projects, pic, 8051, avr and arm projects. download 8051 projects, tutorials, libraries, sample codes. join the microcontroller discussion forum and ask doubts regarding electronics. the best source for 8051 over internet. en-gb 2008 Rickey's World contact@nospam.com (Ajay Bhargav) contact@nospam.com (Ajay Bhargav) Thu, 08 Jan 2009 20:52:02 -0800 Thu, 08 Jan 2009 20:52:02 -0800 http://backend.userland.com/rss e107 (http://e107.org) 60 Search Search 8051 Microcontroller Projects AVR PIC Projects Tutorials Ebooks Libraries codes query http://www.8051projects.net/search.php Heart Beat Sensor http://www.8051projects.net/forum-t5948.html Sat, 16 Feb 2008 13:19:15 -0800 http://www.8051projects.net/forum-t5948.html Re: Heart Beat Sensor http://www.8051projects.net/forum-t5948.html contact@nospam.com (Ajay Bhargav) Mon, 25 Feb 2008 12:14:50 -0800 http://www.8051projects.net/forum-t5948.html Re: Heart Beat Sensor http://www.8051projects.net/forum-t5948.html contact@nospam.com (Ajay Bhargav) Tue, 26 Feb 2008 01:01:28 -0800 http://www.8051projects.net/forum-t5948.html Re: Heart Beat Sensor http://www.8051projects.net/forum-t5948.html Ajay wrote ...

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

]]> contact@nospam.com (Ajay Bhargav) Sun, 02 Mar 2008 10:10:07 -0800 http://www.8051projects.net/forum-t5948.html Re: Heart Beat Sensor http://www.8051projects.net/forum-t5948.html ]]> contact@nospam.com (Ajay Bhargav) Mon, 03 Mar 2008 11:45:52 -0800 http://www.8051projects.net/forum-t5948.html Re: Heart Beat Sensor http://www.8051projects.net/forum-t5948.html contact@nospam.com (Ajay Bhargav) Mon, 03 Mar 2008 11:46:06 -0800 http://www.8051projects.net/forum-t5948.html Re: Heart Beat Sensor http://www.8051projects.net/forum-t5948.html
and... i hope binu has no problem with sharing his circuits ]]> contact@nospam.com (Ajay Bhargav) Tue, 04 Mar 2008 09:46:00 -0800 http://www.8051projects.net/forum-t5948.html Re: Heart Beat Sensor http://www.8051projects.net/forum-t5948.html ]]> contact@nospam.com (Ajay Bhargav) Tue, 04 Mar 2008 11:19:18 -0800 http://www.8051projects.net/forum-t5948.html Re: Heart Beat Sensor http://www.8051projects.net/forum-t5948.html what is connection of heart beat with IR sensor? ]]> contact@nospam.com (Ajay Bhargav) Tue, 04 Mar 2008 11:51:05 -0800 http://www.8051projects.net/forum-t5948.html Re: Heart Beat Sensor http://www.8051projects.net/forum-t5948.html
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
]]> contact@nospam.com (Ajay Bhargav) Tue, 04 Mar 2008 13:19:48 -0800 http://www.8051projects.net/forum-t5948.html Re: Heart Beat Sensor http://www.8051projects.net/forum-t5948.html ]]> contact@nospam.com (Ajay Bhargav) Sun, 05 Oct 2008 19:53:32 -0700 http://www.8051projects.net/forum-t5948.html Re: Heart Beat Sensor http://www.8051projects.net/forum-t5948.html
you can also get a heart beat sensor from here :

http://www.sunrom.com/index.php?main_page=product_info&products_id=556&currency=INR


Arun]]> contact@nospam.com (Ajay Bhargav) Sun, 05 Oct 2008 23:42:07 -0700 http://www.8051projects.net/forum-t5948.html