IR Plethysmograph

Plethysmograph is an infrared photoelectric sensor used to record changes in pulsatile blood flow from the finger. The Plethysmograph operates by recording changes in blood volume as the arterial pulse expands and contracts the microvasculature.
This circuit will provide an alternative method to visualize pulse rate for the children and remove the complications of electrode application. An enclosure will be made to help deliver a consistent view of the pulse rate and remove any motion artifacts that might be visible. The ideal enclosure could be as simple as a clothes pin. The following video also demonstrates our latest working beat detection method displaying the heart rate.

Video Demo:

ECG Prototype 2

Jake delivered a new prototype with an enclosure to support our Bay Area deployment. I've checked out the latest hardware and have modified the heart rate method to correctly perform beat detection with a normal/positive QRS waveform.

Bay Area Pilot

Luckily a Marin County Middle School teacher has contacted us to participate in our very first launch of our prototype . Kassie Petrick has graciously offered us her support in the development of a lesson plan incorporating our biomedical prototypes. The lesson plan will begin with a basic introduction to the human body and then lead into a history lesson on the discovery of "vital signs". Afterwards, students will participate in manual exercises of pulse monitoring (via stethoscope and wrist/neck) and then an explanation of "lub-dub" will follow to describe the anatomy of the heart. Finally an electrical perspective of the heart's contraction will provide background for the autonomous methods ECG and Pulse Monitor (Plethysmograph) circuits. The lesson plan will be delivered to Kassie's 7th and 8th grade students and I'll be present to assist as well as monitor the kids' reception of the activity/capability. Hopefully a few students would be interested in pursuing developing a science project/health related project around this peripheral. The XO chapter of the lesson plan will be delivered on May 29th.

Lesson plan to be posted on our Google groups:
http://groups.google.com/group/olpcgoldenstate