a wristed development

I'm still using fitbit as a kind of health tracker. I like that it is stealthy, meaning that I can use it without it being visible, unlike many of the others with their illuminated arm candy. It also syncs wirelessly and without me needing to do anything, except remember to charge it about once a week.

As blogger FAQ mentioned the other day, there's a whole next generation of wearable devices getting prepared, some of which are going for a more analogue look. The Withings Activité is a great example, with its fundamentally stylish analogue watch plus the added accelerometer, altimeter and bluetooth to permit more or less the same tracking as the fitbit.

At the moment various Google and Apple devices are also being prepared, following the announcement of the relevant health kits and similar as the basis of hubs to provide the services. I see Withings and Nike are already 'close' to Apple on these hubs.

As a user of fitbit and also of various Garmin devices when I cycle, I know that there's a certain additional encouragement when there's some metrics to cross-check. It's a bit corny to mention the 'what gets measured get managed' kind of line, but it is true and I know I keep more of an eye on step-counts, calories and heart rate type things as a result.

So if the Apple Quanta iWatchy thingy eventually emerges, it will be interesting to see the trade offs between amount of sensors, battery life, style and 'glanceability'. That last one is becoming a key design point with things on the wrist. How simple are the gestures to change modes and how simple /legible is the actual device?

I suppose style is personal, but some of the watches (including my Garmin) look a bit like something from a cereal packet. As I only use the Garmin watch if I'm doing something that requires bright clothing, then it probably doesn't matter too much.

I wonder if a sensor race will break out? How many sensors/measures make, er, sense?

Easy
1) Accelerometer - to measure steps - in terms of battery use, this could last a year as a step counter.
2) Altimeter - to measure height but also ascents/descents (e.g. flights of stairs). Also battery efficient.
3) Positioning - expensive on battery - a GPS sensor - my Garmin watch has that but it burns the battery fast. Probably takes the battery down to day-ish.
4) Activity rate - such as low, medium, high - the fitbits do this kind of thing from the accelerometer.
5) Need for activity - really a timer. Easy.
6) Calories burned - use a simple calculation from body weight and activity level.
7) Thermometer - ambient temperature anyone?
8) BMI body mass index. Needs weight for this, but I guess the watches will have a link to scales. Even my bike computer can do this.

Fairly easy
6a) Heart rate in watch - tricky on a watch - they usually use skin colour (i.e. to spot the heart beat) but it's an expensive battery user.
6b) Heart rate near watch - what I use - which is a heart rate belt, which is low power and lasts for months. Needs to be picked up by ANT+ or Bluetooth. My Garmin watch can pick up this signal, as does my bike stuff.

Slightly more complicated
7) VO2 max - kind of lung capacity related - a calculation derivable from some of the others, as long as there is also a heart rate being measured. My current watch does this (probably quite poorly compared with a 'lab test')
8) Jiggle - How much up and down in a step? A fancier version of an accelerometer. which can pick up on posture. My heart rate belt does this, I can't see it working in a watch. Also raises a basic question about wrist mounted activity measure. Not much use on a bike, for example.

Needs to link to something else
9) Blood Pressure/Cholesterol/Insulin - I can't see how this would be possible inside a watch type device. But it could store it from another dedicated device.

Other stuff
I suppose payment protocols, ticketing and proximity charging would be other useful non health things to embed.

We seem to have a couple of directions opening up for these devices. Simple sensors with linkages to a glanceable display vs something that tries to repeat most of the phone functions on the wrist?

And then to figure out a style that doesn't look like something out of a toy factory. The wrist is still prime real estate.