Nightscout: now on the 640g

I've been a keen follower of Nightscout and the whole We're Not Waiting movement for sometime.

However, as the Nightscout solutions have revolved around the Dexcom G4 and previous generation Medtronic pumps, we've been forced to look, but not touch the Nightscout riches.

Not any more though.

I'm sat downstairs typing this, keeping an eye on Janki's CGM readings from her Medtronic 640g upstairs via Nightscout:

And I love it as much as I thought I would :-)

What this is:

• Automated (for up to a day currently) transfer of 640g CGM data into Nightscout
• For remote monitoring inside the home or school classroom environment

And what it isn't:

• Ready for prime time: this is at Proof of Principle development stage
• Fully mobile: it is not as mobile as an xdrip / Dexcom receiver solution (read on)
• Iinstantaneous: there is a 5-10 minute delay on SG data with the current setup

I'm posting this to show other 640g users that there's NS hope, not to claim a final, polished solution exists.

When Janki started on the 640g we knew the radio frequency would be different and that the newly minted Medtronic Nightscout port (mmcommander), then very recently released by Jesus Berian, would not work.

What I didn't realise at the time was that the radio would also be encrypted for the first time [not necessarily a bad thing as the transmitter now calculates SG as well just pushing out raw ISIG] and the radio data packet would also be shaken up...

What to do?

Well, in-between marveling at the very neat solutions - both hardware and software - coming out of Nightscout and hearing of the blood sweat and tears spent by others trying to unlock the 640g we were encouraged to read about Medtronic's MiniMed Connect launch earlier this autumn in the US (on the previous generation of pumps) and to see a community solution (led by Mark Wilson) porting that data over to Nightscout via CareLink (I did look at that code for this project, but have not included it in this solution - it does look like a great platform to develop further then Connect eventually becomes available!)

I know MM Connect exists on the 640g, at least in prototype form. However, Medtronic will not reveal a launch date for the Connect in the UK on the 640g, nor even confirm it's coming (I read a community post quoting 2017 for European release but I have no idea if that's accurate. I hope it isn't).

The Sound of Music

So I started working on a mobile solution, which focused on the pump alarms, using a sound recognition app and just required Janki to carry a small, light-weight mobile phone with her. Although that was useful and works well, particularly for monitoring in the evenings and overnight, it isn't 100% reliable and does not always relay alerts immediately.



Give me the Full Picture
But I really, really wanted Nightscout on the 640g and, after spending time with some of the wonderful UK NS Faculty and NS's one and only Wes Ton the other week, I was more determined than ever to make it work, one way or another.

Anyone reading my September blog on the remote alerts, may have picked up on my thought process of how I was going to achieve this... :-) In a nutshell, my current solution runs using a combination of batch / shell scripts to pull the CGM data from Janki's 640g via CareLink. The CSV file is then extracted from CareLink and relevant data extracted. That dataset is then sent up to our Nightscout website via the standard API using cURL. In its present form it requires a Windows 7+ laptop or tablet (due to CareLink) and an internet connection (3/4G or WiFi).

A Bayer Contour Next Link 2.4 BG meter needs to be plugged in throughout (i.e. you'd be wise to use a spare - linked - meter). The scripts are designed to run for up to 24 hours without user intervention and poll the pump every 5 minutes. [At present I'm using every 10 minutes whilst I get a better feel for any significant battery impact on the pump side - nothing of note yet].

On the Shoulders of Giants...
I'm far from the first person to do something like this in the world of CGM data.

Indeed, I believe John Costik started his remote T1D monitoring in a similar way.

I'm also indebted to Ben West who developed a small suite of utilities (mmcsv) to fetch and parse CareLink CSV files from the previous generation of Medtronic pumps. Although I wasn't able to use the fetch components, have made a number of changes to his efficient code to allow me to use it extract the CGM data from each 640g CSV file.

At the moment, I'm working through the other parameters in the CSV file. From the example data I've seen, the 640g CSV file has significantly more data locked away in it than the older Medtronic pumps. It'll be fun to get as much of that over and up into Nightscout as possible :-)

I'll try to get more info up very soon, but for now, after a week of wonky Enlite sensors and very little sleep, I'm going to leave this one here and just enjoy finally getting automated remote access to Janki's 640g CGM data.

Thank you Estelle for the spare Bayer Contour Next Link 2.4! And a huge thank-you to the developers and supporters of Nightscout who have allowed us to reclaim our T1D data.

As ever, feel free to post a comment below, on Facebook or on Twitter :-)

Update: If you've landed here looking for Nightscout on your 600-series pump, thanks for stopping by :) The simplest way to get your pump on to Nightscout is to use the 600-series Android Uploader. Enjoy!