Also, you may have read this, but we are not the only ones trying to find the solution for non-invasive blood glucose sensing; it is a crowded field.
Nevertheless, I direct you to the final paragraph that states:
"Considerable progress has been made in the development of non-invasive glucose devices however, at this time, frequent testing using invasive blood glucose determination via fingerstick provides the best information for diabetes disease management. Industry spokespersons have said: “… anyone who can come up with a viable noninvasive or painless technique is going to make a lot of money. People’s lives are involved ... and we don"t want to suggest that this technology is right around the corner. This is very tricky, difficult work".