Commonly used arm positions can overestimate blood pressure readings: study

I was also fed up with inaccurate readings, and was trying to prototype a medical device that would have an adjustable cuff based on arm size. I ran it by my concierge doc, but apparently the latest tech is to use light waves to measure BP, similar to how wearables are doing pulse OX and Heart Rate. The technique is known as Photoplethysmography (PPG).

There are devices that are sold with various swappable cuff sizes.