Stumble It!
Abbott Navigator: A First Look
As of Sunday evening at 9pm, I’m on the Navigator! That would be the newest continuous glucose monitoring system from Abbott Diabetes, approved by the FDA this past March. Approval took much longer than expected, while the company had been promising me a close look at the product for over a year, in part because I’d just missed out on participating in the local study. Anyway I’m hooked up now, and quite excited to share my thoughts!
I spent about an hour and a half going through the basics with the company’s clinical science manager, who happens to live in the next town and was kind enough to make a house call. It was an easy setup because: 1) I’ve used two other CGM systems before, and 2) I’m a long-time FreeStyle user, so totally familiar with their test strips, lancets, etc. The latter probably makes me a little biased toward this CGM system; I loved the look and feel and perceived ease-of-use right away.
Here are some of my first impressions:
WHAT’S DIFFERENT
Well, the first thing that hit me was the packaging; nobody eating carrot cake on the front of the box. And they were pretty sparing with the excess cardboard and foam. Both pluses right there for my “feel good” factor, although utterly irrelevant to system performance 
The default view of the main screen features big, clear numbers, not graphs. If you want to see the graphs, you have to push a series of buttons to enter the “Reports” menu, then select “Line Graphs” and choose from 2, 4, 6, 12, or 24 hour views. I’m not sure yet whether I like the fact that I’m only seeing a single number most of the time.
A heck of a lot fewer calibrations required! You only need to conduct four calibrations in the five-day wear period — and they are super-easy because the Navigator has a FreeStyle fingerstick meter built right in. You just stick a test strip into the little port on the lower left corner and feed it some blood.
There’s nothing to recharge. The “Transmitter” (Abbott’s term for the piece you wear on your body that houses the sensor) takes a Silver Oxide 357 HC watch battery, and the “Receiver” (controller unit) takes two triple-A Energizer batteries. But here’s the catch: estimated battery life for the Transmitter is 30 days, and the Receiver is 60 days. If the batteries die on you mid-session, you lose the current sensor. So you have to be diligent about watching battery life. Ugh.
The Navigator Transmitter is quite comfortable, if slightly large. The insertion process differs from both the DexCom and Guardian, too. DexCom’s got that nice mini-size sensor (or “Transmitter”), and a pretty easy and painless snap insertion with a smallish disposal plastic piece. Guardian’s insertion is nastier, with that gi-normous needle I hated, but the insertion device is reusable, which is good (less trash). The Navigator, on the other hand, has a largish insertion device that is fully disposable (shown here). You have to push really hard, and it makes a rather unpleasant noise during insertion.
SO FAR…
So my very first morning with the Navigator was a workout day. I calibrated when the thing woke me up at 7am, as required. But I was a little late getting to my breakfast, so the second required calibration, at 9am, was actually rejected: “Cal Failed.” Huh? Turns out the Navigator automatically rejects any attempted calibration when you are “trending,” i.e. when your blood sugar is moving rapidly upwards or downwards.
(hey, that was right after breakfast!)
I think this is a very clever and important feature, as I’m sure my many ill-timed calibrations contributed to my frustration with the DexCom. Calibrations should always be done when your BG level is steady, I have learned, since feeding any CGM system numbers that are moving targets only confuses it.
Right now I’m scrolling through the graphs and checking my post-meal peaks: 231 after breakfast; 208 after lunch (cookies, yeah). I’m loving the way this thing looks and feels and seems to be in pretty tight synchronization with my fingerstick meter (accuracy, hooray!) But I find a can barely see a darn thing without activating the back light each time I pick it up. You can’t change the settings to keep the backlight on, presumably because that would run the battery down way too fast. Dern. That might bother me.
More updates on Flying with Navigator coming here soon.
Explore posts in the same categories: CGM Adventures (Continuous Glucose Monitoring), Products
amy,
Posted by: Kate | July 8th, 2008 at 7:51 ami do believe that the kind of batteries that the transmitter uses are the kind that come in my omnipods - - - maybe a place / way to resuse them? they are still great when i take them out (every time i remove a pod), so here’s to a little hope that my recycling ways are not in vain…
Yikes! That transmitter/receiver (rectangular) looks larger than an OmniPod Pod! I think I would have run out of space on my skin for both had I not switched to the MiniMed Paradigm with Real Time. Their seashell transmitter is much smaller.
Posted by: June S | July 8th, 2008 at 10:35 amYikes! How can you fit a large “Pod” on your body PLUS the large Navigator transmitter/receiver. From the photo, it appears even longer than an OmniPod Pod. (Perhaps the photo is deceptive.)
Posted by: June S | July 8th, 2008 at 10:36 amLove the minimal callibration, though it sounds like you are still testing anyway so I’m not sure how much of a bonus that ends up being. I’ve heard great things about the accuracy, too.
The cost, though… definitely a hurdle. Assuming this is a loaner, do you think you’ll buy this when the time comes? Or undertake the insurance battle?
Posted by: Kassie | July 8th, 2008 at 10:58 amI’m so excited to see you using and reviewing this product! I’ve worn the dex com and it was less than stellar for me…how much do the watch batteries cost? I assume the sensors are comparable with dex and minimed. Hmm. Will be waiting for your comments in a few days!
Posted by: barbara | July 8th, 2008 at 1:02 pmI want one of those!
Wonder when they’ll be availiable here in Norway, and if I can get one …
Posted by: Viranth | July 8th, 2008 at 2:03 pmLooking forward to reading all your comments about the Navigator. Thank you for sharing.
Posted by: Ellen | July 8th, 2008 at 4:07 pmMy son has been using the navigator for 6 weeks now. Impressions:
- Very accurate on the abdomen, less accurate on the arm
- Very good and timely alarms, excellent trending info you can work with
- Transmitter a bit big, but what the hell
- Tremendous help when doing exams, sports or driving.
You can manage to avoid both lows and highs by reacting to the trends (though it is more difficult to avoid highs than lows). If you wear the cgm and behave as you did before and react to it you will definitely increase time spent within euglycemic zone. What does happen however is that he can now do things he could not do before, so he does them (e.g. eating pizza, KFC or other things that are difficult to control). Fingesticks apart from calibration are down to 2-3 (or less) per day
Posted by: Titos | July 8th, 2008 at 4:09 pmAmy,
Once again thank you so much for sharing all the wonderful information that you do.
It looks a bit large to me, but if it is accurate I would be thrilled, as for right now I am not using my Medtronic CGM.
Keep us posted.
Posted by: karend1 | July 8th, 2008 at 6:33 pmAmy, just wondering … values above 200 TWICE a day? And that with all the gear you are using? Isn’t a pump supposed to keep you much much lower? I mean, even with just pens I manage to stay below 170 right after breakfast plus a pretty tight business schedule. I wouldn’t even be able to *think* straight with a 231. Hope you’re doing well, of course. Just wondering …
Posted by: ACat | July 8th, 2008 at 11:06 pmAmy:
Thanks for the thorough review of the Navigator. I just linked to it from both the Continuous Glucose Monitor Users group and the Continuous Glucose Monitor Forum in TuDiabetes.
Take care,
Posted by: Manny Hernandez | July 9th, 2008 at 1:20 amHi Amy — Did you ask the trainer about the Navigator warning which states: “A portion of the membrane polymer will remain in the skin each time the sensor is removed. Although no health effects were observed or reported in clinical studies, the long term effects of the sensor membrane fragments remaining in the skin have not been determined.” — This is from Abbot’s “Brief Statement of FreeStyle Navigator System Uses and Risks flyer ART14904 Rev. A.
Any thoughts or comments on this issue?
Thanks.
Posted by: John | July 9th, 2008 at 4:49 amYes, John, we did talk about that. Apparently some micro-particles of plastic can remain in the skin. They haven’t found any ill effects. The risk seemed equally “micro” to me.
Your thoughts?
Posted by: AmyT | July 9th, 2008 at 7:24 amI have to say the thing looks huge but I will admit I am biased since I use CGM through my Minimed pump. I find that my current sensor can get in the way especially during a Yoga class. All that bending can make it difficult to keep it in place.
I am glad however that there are several choices out there in the market place. My insurance covers my sensors and the more people that use CGMS the more likely insurance will be will to pay for it. Especially if it saves people from have complications from going low.
Posted by: Dave | July 9th, 2008 at 7:38 amHi Amy — Hmm… My concerns are with how much of these particles are left in the skin, if they ever disintegrate (or migrate), if, over time, the accumulation of these particle interferes with glucose readings, and how these particles may ultimately affect insulin absorption… especially considering that the Navigator shares the same “real estate” as infusion sets, pods and needle-stick sites used to deliver insulin, symilin, byetta, etc… We already know that infusing insulin may cause scar tissue in patients over time, leading to decreased infusion sites… Will the same happen with the puncture left by a CGM system, and will this be exacerbated by a footprint of “micro” particles?
Posted by: John | July 9th, 2008 at 8:27 amAmy,
Great post thank you for this.
gina
Posted by: gina | July 16th, 2008 at 1:31 pm