Dexcom Software 505

24 hours later.

Why is Software 505 a big deal? Let’s step back for a moment.

“CGM accuracy is measured by the mean absolute relative difference (MARD) from a patient’s reference values obtained from blood glucose measurements from a lab analyzer, YSI (Yellow Springs Instrument). A lower value indicates closer accuracy to reference values.” Dexcom’s G4 Continuous Glucose Monitor, pre-software 505 has a MARD of 13%. Software 505 improves that MARD to 9%.

Remember, lower is better in this case.

If you need another reference, this new algorithm is used in ongoing Artificial Pancreas research. Between the statistics, and the “vote of confidence” that comes with being associated with Artificial Pancreas trials, I was sold. Yes, updating to 505 meant all past data on my receiver would be removed. Yes, updating means starting a sensor over – I suppose this was just fortunate timing. After a quick download on Chromadex/Nightscout CGM Utility, I was prepared for greatness.

The problem with all of this is that my primary computer is a MacBook. My Dell is literally collecting dust in a closet. But, that dust magnet was my only means for updating to this newer, better, blood glucose monitoring software. I shouldn’t be surprised at this restriction considering this is the same company whose uploader software is only compatible on Windows, but it’s still disappointing. This selective development ostracizes part of their user base and unnecessarily segregates Dexcom faithful into haves and have-nots.

Conversations about device interoperability and data access aim to address these problems (among others). Operating systems should not be a barrier to entry to data access and improved diabetes care. While the excuses for these limitations will become more trivial as open source solutions take the lead in improving diabetes care, technologically speaking, it would be nice to have some official support from the companies that have a direct impact on our, on my health.

Visit for more info on Software 505.

Oh, I’ll share thoughts about 505’s accuracy down the road if appropriate. I’ve never had any glaring problems with the G4’s accuracy before, so I’m not sure if I’ll be able to notice a genuine difference without booting up a second receiver – which I don’t have. I’m willing to believe better is better on good faith. (Reminder: not a doctor.)

One thought on “Dexcom Software 505

  1. Mac vs. PC issues aside, the improved accuracy PLUS the smaller transmitter makes the system quite alluring; moreso than before.

    I also find it fascinating how the software can really improve accuracy that much. I figured most of that aspect was built into the sensor itself.



Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s