Improve Digital BP Monitor Accuracy

I own several popular off-the-shelf digital blood-pressure machines but notice that readings fluctuate whenever the cuff fit is less than ideal. From my observations, cuff size—and the comfort level that goes with it—is one of the sources of these errors. Some other modifications are also required such as (1) The level up to which the BP cuff should be inflated (2) The rate at which the cuff should be deflated. I want to redesign the cuff as well as modify the inflation level and deflation rate to reduce the likelihood of incorrect Blood pressure measurement.

Here is what I need:
• A re-engineered cuff concept that prioritises comfort (so users keep it positioned correctly) without sacrificing the airtight integrity required by oscillometric sensors.
• Materials selection and mechanical drawings (CAD or comparable) ready for prototyping.
• The level up to which the BP cuff should be inflated should be programmed.
• The rate at which the cuff should be deflated should be programmed. Your task is to modify the cuff size of digital BP machine readily available in market, and also create a program so that the cuff inflation and deflation is modified as mentioned above, thus producing a newly modified digital BP apparatus. The exact modification of cuff inflation and deflation will be discussed after signing NDA and IP right through personal email.

If you have experience with biomedical device reverse engineering, and device fabrication, or have worked on digital BP algorithms sensors and output, your insight will be invaluable.