Continuous glucose monitors have been around for a while now, indeed I’ve been using one to improve my control for the last 5 years. The market has been dominated by three main players, all with very similar devices, at very similar – and for many out of reach – prices. That could be about to change.

I spent a few hours with California based C8 MediSensors last week looking at their new take on CGM, which just like the blood glucose meter, was invented by the father of a diabetic child looking at current treatment and thinking, we can do better than this. Rather than measure glucose levels from the inside, using a sensor beneath the skin, their device fires a beam of light through the skin to measure the level of glucose in the interstitial fluid. That’s right, no needles and no blood. They’re in the process of gaining CE Mark approval which will allow them to sell their optical CGM device in Europe, hopefully this year.

You wear the device, which is slightly bigger than an insulin pump, and its smaller battery pack next to your skin, attached via a material belt that goes around your waist. You view your BG measurements via an app on your smartphone.

Looking at this from the view of someone who already uses CGM, I’m excited. I know the benefits (and frustrations) CGM can bring, but I also know that that funding can be very hard to get and the ongoing cost of consumables make it too expensive for many people to consider. The C8 has the potential to change this. Let’s take a closer look…

The facts about C8 MediSensors Optical Glucose Monitor System:

• Accuracy: company data shows it to be in the same accuracy range as standard invasive CGM – like any CGM, this is about giving you a better view and context to your glucose levels, not an accurate number at a particular moment you can use to bolus from – you still need blood tests for that.
• Techy stuff: the C8 uses Raman Spectography to fire light through your skin and vibrate your molecules. As each molecule has a unique signature, the device can identify the glucose molecules and count them (in all honesty, it’s a bit more complicated than that, but you get the idea, there’s a full explanation here).
• Cost: this is a major winner. The C8 will retail at US$4,000 (around £2,500 at today’s exchange rate). That’s about the same cost as one year’s supply of CGM sensors based on using one a week. The C8 will be guaranteed for around 2 years (varies according to country) and is expected to last at least 4, with running costs minimal in the tens rather than hundreds or thousands of pounds. That makes CGM, while still not cheap, significantly more affordable. Plus it comes with a 30 day money back guarantee – so you have time to play around with it and if you decide it’s not for you, send it back.
• Availability: hold your horses, this is an investigational device not yet on sale anywhere. CE Mark approval is on the cards for later this year, after which it will launch in Europe. I have no timescales on a US release.

Using non invasive CGM:

• No pain: as it’s non-invasive there are no needles or insertion devices. Skin irritation is always a concern when you have something on your skin for long periods of time – but I guess you’d have to try it to see how it works for you.
• Getting started: when you strap on the system, it should be up and running in around 15-20mins and need one blood test to calibrate (it basically has to warm up, so if you’re hot it’ll be quicker, but will take a bit longer if you’re cold). The only time it should take longer is the very first time you use the device, when you’ll have a 45-60min warm up. This compares very favourably to around a 2 hour warm up for the invasive models.
• Monitoring the results: the C8 device has no separate monitor, instead it transmits its results to an app on your smart phone. The app currently works on Android phones, with an Apple version planned.
• Alerts: high/low alarms will sound on your phone, not on the device itself – this might help with the perennial CGM problem of the alarms being too quiet – on a phone they should be easier to tailor.  At the moment there are no rate of change or predictive alerts, but they are a future possibility.
• Battery life: Around 10 hours, with 2 batteries provided as standard. So you’re going to need to recharge daily, compared to weekly at the most for other CGMs. Powering your own laser beam takes a fair amount of power.  Plus you need to make sure you keep your smartphone fully charged, as that’s how you view your results.
• Sex appeal: the device and battery are pretty bulky and are worn strapped to the stomach via a material belt. Compared to the tiny Dexcom and Medtronic transmitters, which are just a bit bigger than a 50p piece, it’s a major difference. They are working on improving this for future versions.
• Exercise: the laser does like to be snuggled up close to the skin, without too much jigging around. So at the moment C8 recommend you don’t use it while exercising as it might give erratic readings. I think this’ll be one of those things that users will have to play around with to work out for themselves. On the plus side, it is easy to take the belt off and on and start up time is very fast.
• What about the kids?: at the moment its only been tested for use for those over 18, so although theoretically ideal for kids it isn’t officially approved for them to use.

And of course, who wouldn’t want to be able to say to their friends in the pub “Did you know, I have the world’s smallest Raman spectrometer strapped to my stomach?”.

I think this has the potential to allow many more people to take advantage of using CGM as it reduces the big stumbling block of cost, and removes the issue that some have with painful sensor insertion. As someone who already uses standard CGM, I’m not tempted to switch at the moment – the battery life and size of the device wouldn’t fit with my life. But if I didn’t already have CGM, I’d be looking at this with interest when it comes out.

For more info, take a look at a video of the C8 in action.

As you’d expect, I didn’t spend my own hard earned cash to go and see this, C8 lured me to their offices with promises of expenses, nice sandwiches and an interesting product, which they delivered on.