Personally, I don't believe Wello iPhone case/health tracker works

In an increasingly competitive market for health monitoring, the Wello iPhone 5/5S case is going all-in-one.

It reckons that if you hold it for a few seconds, via Bluetooth its app can provide your heart rate, blood pressure, blood oxygen levels, temperature and heart ECG waves.

There's also for a peripheral you blow into to test your lung function.

Now, I'm all for making the qualified self as easy as possible, but accuracy must come into the picture somewhere.

I'm pretty skeptical about heart rate monitors that aren't chest straps so accuracy taking your blood pressure - a metric I love - through your fingers sounds suspicious to me.

Still, Azoi, the team behind Wello, seems legit and has been working on their tech for a couple of years. It will also be available for Android devices, only not as a case.

Guess we'll find out more when the Wello iPhone case - currently available for pre-order priced $199/£120 - is released.

Next metric for the quantified self is blood pressure

As I've previously suggested, blood pressure is one of the key body metrics; at least I track it. And it's something that up-to-this-point hasn't been addressed by wearables.

That's because it can't be easily measured in the way that say, heart rate can be: you need a proper pressure band around the upper arm, and that has to be a separate peripheral.

But it doesn't mean that companies aren't trying.

Blipcare has completed its Indiegogo funding, gaining $23,754 for what it calls the 'world's first wi-fi blood pressure'.

It uses wi-fi instead of Bluetooth so it can be used directly to the web rather than requiring an smartphone app.

More interesting from a wearables point of view, however, is the QardioArm, which takes a more conventional app-based approach, which also uploads your readings to the cloud.

It's raised $131,069 with 14 days left, with the available option being $99 with free shipping to US and UK.

Obviously, it's a wearable, although not something you wear all the time.

D.I.Y. Data: Two months of monitoring my vital signs

Two months ago, I started regularly tracking some of my biometrics using a blood pressure monitor.

It's a semi-serious attempt to see how my body is reacting to the stresses and strains of daily life, and something I'll be looking to continue into 2014.

And with that in mind, here are the first 50 days of the experiment.

I think it's difficult to see any clear trends. I try to take the readings at the same time in my day - at the start - but given my weird operating routine, that's certainly not the same time each day in terms of GMT.

Still, there is a clear downwards trend in systolic blood pressure, although that may partly be because I'm getting more used to taking my own blood pressure.

My diastolic pressure has remained more constant during the period, so the systolic-diastolic line has decreased thanks to the downward trend in systolic pressure. Weight and heartrate have remained steady. 

D.I.Y. Data: Checking my vital signs

Following the self-destruction of my Up band, and general moaning about the lack of open source data, I've come up with a solution.

Well, a solution of sorts. I've started manually tracking myself.

Luckily, we had a blood pressure monitor in a back cupboard and that's the core of my new regime.

When I get up, I weight myself and check my blood pressure and heart rate. That's manually entered into a spreadsheet, and I drop the numbers into a simple graph (below).

It's not rocket science, but checking these vital signs at roughly the same time every day (always before eating) should provide consistent results.

More generally, checking our vital signs is a step beyond the sport and health trackers because you certainly can't take a blood pressure reading without a proper sleeve attachment. However, the monitors themselves aren't expensive and some manufacturers of other health equipment such as Beurer and Withings do sub-£30/$50 examples.

Equally, measuring your blood pressure is medically more important than factors such as heartrate, sleeping patterns or even weight. There's a reason they call high blood pressure the 'silent killer'.

Of course, it is related to metrics such as weight, diet and general fitness, but as you can see, at the start of the process, my blood pressure was rather high.

I've since made some lifestyle tweaks and am happy to see it dropping towards the standard '120 over 80', although I'm sure there's a large psychological element in this. My lifestyle changes are not so radical that it would have had this impact so quickly.

Anyhow, what's more significant for me is not just rely on what my sensors are recording. Sure, that's useful but just because we're measuring something doesn't mean it's important.