In order to plot and slice and dice my health data, I decided to buy a blood pressure meter
suited to tracking.
I bought an Omron Blood Pressure (BP791IT) device (http://amzn.com/B004H44GB4). 
It measures the blood pressure, your pulse, detects heart rhythm problems and also connects to Microsoft HealthVault online to upload its data, which is pretty impressive for $70.
The device is cheap and very sturdy and well-designed and made, if that is your concern.
The feature to integrate with HealthVault also shows some vision from the manufacturer.
I am used to do these things in the style of Quantified Self (QS) and track a number of parameters in order to see correlations. The whole experience with the software has been just ok and leaves more to be desired to improve the user experience, especially for QS. Ideally, a simple CSV should be provided by the driver as a choice and that will simplify things for QS.
Actually, getting the device to connect was frustrating for me and I had to try a little of installing/uninstalling things to get it to work.
Maybe, the mistake I made was to also install the Omron software, which could get data from the device and show it and this installed a driver which somehow interfered with HV, I don’t know.
It is not so explicit, but you must make a choice of which software you want to use viz. the Omron software or HealthVault and install things with that in mind.
If you want to really graph and correlate things or have your own method for QS style work, then I suggest you go with the Omron software, import the device data with it and export a csv file so you can use that in your tool of choice.
Both softwares do a straightforward graph plot but I have found that QS work needs correlations between tracked data (e.g. caffeine and BP) and I have to still come across a good tool other than Excel to do this.
You cannot really do this correlation with HealthVault and I’ll cover this software in a future post.
The way the Omron BP791IT (and other HealthVault devices) works is that you need to have a HealthVault (HV) account and you then install an HV connector which is the glue that connects to your HV account (in the cloud) to the device through a driver.
So, this connector will take care of the plumbing required to detect a device, read from it (using it’s driver), upload the data, etc.
Now that it is all set up, it works well and I have to take readings and connect the USB cord and the HV connector detects it and uploads the required data.
You can then go to your account and see the data and also graph it.
Pretty good for the upload but not a great user experience with the software itself.
Anyway, the conclusion is that the Omron BP791IT is a great device and is good value for money and the Omron software is good if all you care about is tracking your blood pressure and pulse.
Things get more complex for QS style tracking if you want the data to be more open (as is with most software).
This human life 