Disclosure: member of family (not me) is Type 2 and uses an interstitial fluid Continuous Glucose Monitoring system. It does involve a small, extraordinarily thin needle in an adhesive sensor, piercing the skin. We change it out every 15 days.
Genuinely reliable Non Invasive (NI) glucose monitoring is still a work in progress. Promising research devices involve three factors at the fingertip: light at several defined wave lengths passing thru the fingertip tissue and the capillaries found there, RGB color spectrum analysis of capillary contents at the skin/fingertip test site, and finally, time. Here's a brief summary of one test (that is maybe more than you want to know)...
The technology underlying the NI measurements is presented in detail in the same issue of this journal.20 In brief, four light emitting diodes (LEDs) within the finger compartment emit a discrete wavelength from ~ 600 ~ 1000 nm through the fingertip. As the light wave passes through the tissue and blood capillaries, the light is partially absorbed and consequently, the light signal is changed. The traversed light is then projected onto a color image sensor (camera) of the device. The camera photographs in real time the light that traverses the fingertip tissue. The color images are stored in a digital memory for analysis by a dedicated algorithm executed in the digital processor unit. The six-dimensional signals (position [x, y], color [R, G, B], and time [t]) are associated with tissue glucose levels by means of adopted algorithms derived from brain neural mechanism to extract order out of disorder.
Source: 2018 study,
National Library of Medicine
Yeah, it's 7 year old information, but these things move slowly and deliberately (at least in countries where you don't have venture capitalists champing at the bit to rush the product out the door and start raking in the bucks.)
Bottom line: #1) consult with your diabetes caregiver /advisor about using NI glucose testing. And #2) rest assured that any NI glucose measuring device hawked by the ads in the margin of your browser is a scam and waste of money. There's
no "galvanic skin response" pad embedded in a finger ring or anything resembling an athletic tracking bracelet that works.
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