I've spent a little time looking at what I can find on the web about Dielectric Spectroscopy, in particular in relation to glucose. I've not yet found the ideal range of frequencies for glucose detection; one source suggests as much as 80MHz, while another as low as 40kHz. The higher the frequency the harder things get. Also, I need to get some experience of the technique and tech in general. So, plan is:

• Start with breadboarding/test equipment to create a minimal dielectric spectroscopy setup.
• Start at low frequencies (tens of Hz) and work up (to tens of MHz).
• Test different electrode styles and evaulate their response (I can think of three styles already).
• Test using known materials in solution (plain water, saline, glucose, possible blood itself) and characterise their signatures across different frequency ranges.
• Test using a running solution (flow through tubing) at different rates and characterise impact this has on the signature. Include case where some material within scope of electrode is NOT affected by flow.

I have more or less settled on an initial architecture for the device; a discrete waveform generator coupled with a discrete phase/amplitude detector, both of which are coupled to a basic micro controller. At this stage this doesn't need to be that powerful; a simple Arduino will even do (I can solve for what micro controller and bluetooth hardware to use latter).

If I move forward then the waveform generator may be replaced with something more basic (all I need is a sine wave with a frequency I can control and which covers the desired range).

So, I've ordered the following bits to start with. Will be a few weeks before they arrive.

• AD8302 Phase/amplitude detector (small and cheap)
• AD9954 High-end DDS waveform generator (large and pricey, 400MSPS, 200MHz max output)
• AD9834 Mid-range DDS waveform generator (small and cheap, 75MSPS, 37.5MHz max output)
• Signal Generator Module (0-40MHz, based on AD9850 - saves time during the bench testing phase)

In the meantime I'll use my other projects to learn more about SMD design/assembly so when the time comes I'll be able to make this into something reasonably compact and wearable!