My group and I are currently working on a biomedical engineering project for our class. Our design idea is a wearable metal detector that uses metallic tracers in the blood to determine the concentration of glucose in the blood. There are multiple aspects of this design, but we wanted to reduce this project down to a proof of concept. We want to make a metal detector that is REALLY sensitive that can detect objects that we can make as small as possible (think iron fillings) that could simulate the tracer.
We plan to use an Arduino to read the changes in coil inductance. The main problem that we are running into is that, being biomed majors, we do not really know much about the electronics and circuits that will make this concept work. We found a few circuits for metal detectors, but we really don't understand what's going on in them. Here's a link to one that I found http://3.bp.blogspot.com/-iu_ERGb6vzQ/Ue2DyIWZYFI/AAAAAAAAAd8/yl2Wk05B37A/s1600/IMG_20130722_202500.jpg.
Main questions so far: Can someone explain whats going on in this circuit? What would the input and output waveforms look like? Can we use a simpler circuit and still get around the same sensitivity? If we want a more sensitive detector would a small coil with a ton of turns be a safe option? We'd like to use two coils concentric setup (one transmitter on receiver) would that add to sensitivity?
Thanks in advance!