A recent study by the Diabetes Technology on a cohort of 1000 people found that of 18 popular glucometers in the US, only 6 met the FDA standard for accuracy:
and another good study on accuracy here: Performance Evaluation of Three Blood Glucose Monitoring Systems Using ISO 15197
I was surprised by 2 things:
- Of course that only 6 BGMs met the standard….
- The FDA standard itself which specifies accuracy of only +- 15mg/dL at or below 100mg/dl and +-15% above that number. If your fasting blood glucose was measured at say 95mg/dl, that could mean to a 95% confidence level you are anywhere from 80mg/dl (relatively close to hypoglycemia) to 110mg/dl (pre-diabetic).
I decided to take a look inside the best scoring BGM: Contour Next One. Basically it looks like this:


Top side features a simple connector housing for the strip insert, a Toshiba custom analogue front end and an MCU.
A decap of the MCU reveals that it is from Renesas and is likely a R5F51135ADLJ (128KB ROM flash, 32KB RAM, 8KB data flash). This is based on Renesas’ proprietary