Creative Connectivity - the site for eHealth, telematics and wireless

Continua Health Alliance takes the bigamous route – Bluetooth and ZigBee.

June 9th, 2009 |  Published in eHealth & Assisted Living  |  3 Comments

After months of debate, the Continua Health Alliance finally announced its choice of wireless technology for low power medical devices.  Bluetooth low energy and ZigBee have been the key antagonists in this process and today Continua decided to make it a threesome and share its bed with both partners.

Both brides proudly announced the forthcoming nuptials, Bluetooth claiming that it had been chosen as the Health Device Standard, and ZigBee pronouncing that it has been selected for the next generation standard.

Whilst most people outside the specification groups will dismiss this as irrelevant, it does have some important implications, as it presents medical device manufacturers with a dilemma – which of these two wireless standards do they choose?  We’re at a point in time where we’re about to witness a new phenomenon of internet connected, consumer medical devices, which will open up the possibility of a new era of personal healthcare.  If manufacturers become confused about which of two incompatible standards to use, they’ll delay their products, with a resulting delay in availability and implementation.  It’s important that doesn’t happen.

At a top level, this decision seems clear – Bluetooth low energy will be used for PAN (Personal Area Devices) – the ones that we carry around with us.  And ZigBee will be used for LAN (Local Area Network) devices – the ones that tend to stay within a building, either a home or hospital.  Go back thirty years and that’s the same sort of differentiation that was applied to telephones.  We had fixed phones in our homes and a few people had walkie-talkies for when they were outside.  But today that differentiation has disappeared.

The same is going to be true for consumer medical devices.  Although they will start out as personal devices that we keep discreetly hidden in our bedrooms or bathrooms, very soon they will become mobile devices.  That’s already happening with sports and fitness devices, where there’s healthy market for pedometers and heart rate belts.  As we evolve through a few generations of products, they’ll become smaller, more discrete and less obtrusive in the way they measure us.  And that equates with more mobile and more personal.  It removes the distinction between PAN and WAN – they just become the things we carry.

 Which brings us back to the dilemma facing device manufacturers.  It’s vitally important that they don’t delay their development plans, but they need to decide which of the two technologies to go with.  My personal view is that Bluetooth will dominate.  There are some technical reasons for that, but the biggest one is not technical – it’s scale.  Bluetooth based medical devices will be able to connect to mobile phones, which exist in billions.  So a Bluetooth medical device already has something to connect to.  In contrast, only a few million ZigBee devices have been sold.  It means that a company making a ZigBee based medical device has the additional cost of providing a ZigBee adaptor that can plug into a PC or phone.  

Vince Holton, writing on the Incisor blog, thinks Bluetooth will dominate.  He quotes Mike Foley – executive director of the Bluetooth SIG, who, when asked to quantify it, said that on a scale of importance, it was (for him at least) “one step below the potential Microsoft Yahoo acquisition”.  I’m not sure that I know what that means, but it sounds convincing and ought to get the financial community interested.

 Bluetooth provides the scale that is the honeypot for applications.  There’s already a growing and enthusiasm community of application developers writing apps for mobile phone.  Look at the success of the Apple iPhone App Store.  That’s already featuring hundreds of medical and health applications.  The same developers will jump at the prospect of connecting to real monitoring devices.

We don’t yet really know how the personal health device market will evolve.  We’ll only discover that when devices exist and applications developers start to play with them.  It’s important that they see this decision as the starting pistol to develop devices and not as one that makes them sit and wait.

For more information on the consumer medical ecosystem that Bluetooth will enable, download the White Paper: A Bluetooth Ecosystem for Health and Fitness .

3 comments ↓

#1 David Doherty on 06.12.09 at 10:05 pm

The only benefits i can see in making this arbitrary differentiation is that it will ensure slower adoption and help the established manufacturers (who fund the existence of the Continua Health Alliance) to maintain the status quo a moment longer.

IMO the starting pistol was fired a while ago and (as you rightly point out) the scale of Bluetooth in the market means half the race has already been run. There is no time for sitting round listening for the last lap bell!

#2 Mikell van der Laan on 10.02.09 at 1:36 am

Picking one over the other serves no purpose other than illustrating the person doing the picking understands little of each protocol or their true utility. It’s about like claiming motorcycles will replace cars in the very near future. While both vehicles, each has its own RIGHTSIZED purpose and will never eclipse the other.

Zigbee will dominate in all applications needing light or marginal data exchange but heavy 3D location in giant or small spaces, for which there are countless needs in the medical field.

Bluetooth will be the PAN for all of us, but never allow location services with resolution great enough to really make it useful for that purpose. On the other hand, its data transfer ability is unmatched.

#3 Nick on 10.04.09 at 6:37 pm

It is absolutely correct that wireless needs to be chosen on the basis of the application. Unless you do that, then you will end up with a product that at best will only perform adequately, and at worst, not at all.

However, the issue here is not a choice of “standard” Bluetooth and ZigBee, but the new Bluetooth low energy standard and ZigBee. Bluetooth low energy is totally different to the Bluetooth that is used in phones and medical products today. Like ZigBee it is designed for light and marginal data exchange, but with the added ability to talk to the next generation of mobile phones.

In the Continua world most products implementing one of these standards will operate in a cable replacement or multipoint mode, neither of which needs an advanced topology. In this case I believe that Bluetooth low energy has the key advantage of being able to connect to hundreds of millions of mobile phones. The problem of having two alternatives is that medical device manufacturers have to make a choice of which to add to their products. It won’t be both, as that is too expensive an option. Nor do I think there is an obvious demarcation of applications, as many of the prospective use cases are valid in relatively static environments, such as clinics, as well as in a mobile environment.

Without guidance, the market will decide. My suspicion is that the ability to connect to a cellphone will be the dominant decision that they make. Each standard has other good features, but the prospect of connecting a device to a mobile phone and hence to a web application is a powerful one, particularly for consumer healthcare devices.

I think that the need for location may become redundant as a result. If a device is fixed, it’s not important, as location information can be programmed into it when it’s installed. If it’s mobile and connected to the phone, then it can use the handset’s GPS facilities. That leaves asset tagging, which is still fragmented between active RFID, low power 802.11 and some proprietary time of flight implementations on 802.15.4 chipsets. I’m not sure that there will be much consolidation in this area, leaving the choice of Continua wireless standard down to the market.

So returning to your RIGHTSIZED comment, Bluetooth low energy has the mobile phone connection, standard Bluetooth has the higher bandwidth, but I struggle to see what ZigBee offers in this particular market.

Leave a Comment

About Creative Connectivity

Creative Connectivity is Nick Hunn's blog on aspects and applications of wireless connectivity. Having worked with wireless for over twenty years I've seen the best and worst of it and despair at how little of its potential is exploited.

I hope that's about to change, as the demands of healthcare, energy and transport apply pressure to use wireless more intelligently for consumer health devices, smart metering and telematics. These are my views on the subject - please let me know yours.

You can Subscribe via RSS »