Some of you might have noticed the blog has been quieter than one of those new fangled electric cars recently.
So I will let you into the loop;
I am currently working on a project involving analog/digital interactions – mainly aimed at music.
The shape that this project is taking is to illustrate the blood flow through your body – so that the changes to the music can be observed (did you know that your heart “tunes” to a bass beat?). The main piece of tech for this project is being able to measure the heart rate of our test subject.
We’ve been through many prototypes of using different methods, most recently lasers. They have all so far delivered results but none I am happy with.
However today we are switching to using infrared diode’s and phototransistors. The theory behind this is that when your blood pumps, the blood vessels under your skin fill with blood, which absorbs some of the IR light – instead of reflecting it. So if the IR emitter is set to reflect off ones skin into a phototransistor – a difference in level can be detected.
From here these readings can be fed into a string of results (or an array) using the PicAxe chip. From here the heartbeat of the subject can be calculated, and any errors can be smoothed or corrected. From this point it is as simple as creating another array that more or less tells the chip how many pulses each “BPM” should have.
From here the chip can operate a relay which will light a length of EL (Elecrto-Luminescant) wire which will be arranged to mimic or simulate the wearers veins. The final design is set to fully cover both lengths of arm – however at this stage the length of one forearm will be used.