/challenges-projects/design-challenges/enchanted-objects/b/blog/posts/magichat---4---heart-beat-sensorOne of the most challenging part of this project is to measure the heart beat (and then blood pressure)Hear beat measuring is based on the principle of photoplethysmography (PPG) which is a non-invasive method of measuring the variation in blood voluen-USTelligent Community 12https://community.element14.com/challenges-projects/design-challenges/enchanted-objects/b/blog/posts/magichat---4---heart-beat-sensorMon, 30 Mar 2015 21:28:53 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:e101544a-e63d-49e1-a9f6-9dd0d2ff39f9crjeder1<p>An other nice idea is what I found at Hackaday: <a class="jive-link-external-small" href="http://hackaday.com/2015/03/19/measuring-heart-rate-with-a-piezo/" rel="nofollow ugc noopener" target="_blank" title="http://hackaday.com/2015/03/19/measuring-heart-rate-with-a-piezo/">Measuring Heart Rate With A Piezo | Hackaday</a></p><p>And I am wondering if IR is the right wave length because some smart wathches use green light because it can penedrate the skin, as far as I remember.</p><p>Found something while I was looking for a reference:</p><p><a class="jive-link-external-small" href="http://www.osram-os.com/osram_os/en/press/press-releases/ir-devices-and-laser-diodes/2014/compact-osram-sensor-improves-fitness-monitoring/index.jsp" rel="nofollow ugc noopener" target="_blank" title="http://www.osram-os.com/osram_os/en/press/press-releases/ir-devices-and-laser-diodes/2014/compact-osram-sensor-improves-fitness-monitoring/index.jsp">Compact Osram sensor improves fitness monitoring | OSRAM Opto Semiconductors</a></p><img src="https://community.element14.com/aggbug?PostID=20322&AppID=117&AppType=Weblog&ContentType=0" width="1" height="1">https://community.element14.com/challenges-projects/design-challenges/enchanted-objects/b/blog/posts/magichat---4---heart-beat-sensorMon, 30 Mar 2015 08:28:47 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:e101544a-e63d-49e1-a9f6-9dd0d2ff39f9mcb11<p>Looks great.</p><p>&nbsp;</p><p>If this doesn&#39;t work, let me know as I have a circuit we used in disco lighting equipment to adjust the gain, but respond to the bass pulses.</p><p>I&#39;m sure it could be adapted to give a potentially much greater range.</p><p>&nbsp;</p><p>Mark</p><img src="https://community.element14.com/aggbug?PostID=20322&AppID=117&AppType=Weblog&ContentType=0" width="1" height="1">