24 hour blood pressure recording can save lives, and avoid unnecessary medication.
But! the present products hurt to much while measuring and/or cost too much or are too bulky,
so are not used. Look at chart below, listen while you read to you tube audio

Goal: to make an arduino based 24 hr arm strap BP recorder:
That is not painful and may not wake you up
producing data in Comma Separated Value files, for open access in spreadsheets etc.
using plain ol' disposable AA batteries (no lithium fire while you sleep,reduced product recall risk)
Doing EKG heart trace recording an other sensors at the same time. Probably sensor is Honeywell self digitizing pressure sensor @$45 each, Olimex arduino board and EKG boards. It is possible that a rental by mail service will make it easier to achieve product recalls, especially in the early stages where it is more likely. Or this is a purely experimental open source development kit, that may not be subject to government approval as it is not a consumer device, this may depend of the level of funding achieved here.

The issue of non painful measurement Bp measurement while maintaining accuracy is critical. Some units such as the Panasonic (no data recording or auto trigger, not so bulky but not arm band size) have a measure during compression rather than release and a nice semi rigid cuff which is fast and with minimal pain, but there is a problem with accuracy compared to others, seemingly large outlier measurements is the way the problem seems to manifest.

All BP measurements have a bit if variability some of which originates in the body of the person also. It may be possible to calculate the blood pressure by several pain free algorithms and sensors during the same inflation deflation measurement cycle time to error correct the measurement.

History of our work so far

1.Chinese machine bought and tested, records and exports data with proprietary software clumsy, measurement so painful even when awake as to be unusable as a machine in general 200+$?
2. Omron recording machine with proprietary recording software had minicomputer wired to the start button to trigger periodic BP measurement. The bulk of the machine means even in sleep a person can wake up and pull the machine off of the table while going to the bathroom, or get tangled in the hose. $700 spent on that phase.
3. Doctors describe Welch-Allen recording unit as about 2500 dollars as too expensive, one CHF pharmacist did say there was a new rental reimbursement code that could make it economic. Another doctor said the unit was possibly painful and unpopular with users.
4. Attempts to trigger and data record form the Panasonic above did not prove practical. $???
5. Arm band unit purchased, unusable, unmodifiable @$200
6. Arm band unit found to be a painless type and a 555 timer analog trigger was placed in several and tested with 3 doctors who had varied acceptance levels based on personality. Data had to be taken down with pencil and paper from repeated pressing of buttons. Lithium battery vulnerable to puncture if assembled improperly. @$1000. arm

we did some work in our lab to try to convert existing blood pressure devices into 24-hour recorders. the principal problem is that most of them hurts quite a bit and when you're sleeping you just can't stand it and you take it off and so we did find a brand that was not painful. it depends on how it's done and we did modify it and it worked okay.

it was a tedious mechanical you have to basically write down all the numbers recorded over the 24 hours because there was no digital way of getting it and then the idea was to apply some of those ideas to an Arduino based arm mounted blood pressure and EKG recorder and certainly is possible and some work was done on it.

at the moment it's shelved because it kind of became too big a project for us to manage right now but we do have the information on both of those projects on the website and it could be pursued. it could be very valuable reporting device because some of them are quite expensive and painful to use so an otherwise good idea has been thwarted by poor technology implementation and it's another great area for some improvement in health care.

7. Design and Build of Arduino based system foundered on digression of digitization of pressure sensing issues that should have been sidestepped with purchase of Honeywell predigitizing pressure sensor. Project frozen and shelved and now put up for further funding here and now. @$2000